Moisture-driven Composite Battery from Waste Materials for Sustainable Energy Harvesting

Moisture-driven Composite Battery from Waste Materials for Sustainable Energy Harvesting | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Moisture-driven Composite Battery from Waste Materials for Sustainable Energy Harvesting Aman Ul Azam Khan, Nazmunnahar Nazmunnahar, Mortuza Hasan, Abdul Baqui This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8570579/v1 This work is licensed under a CC BY 4.0 License Status: Under Revision Version 1 posted 10 You are reading this latest preprint version Abstract Atmospheric moisture is an abundant, renewable resource with potential for sustainable energy harvesting. While moisture–material interactions can generate electricity under ambient conditions, most current systems remain expensive, specific environment dependent, and produce voltages too low for direct use in wearable electronics. To address these limitations, we developed a moisture-electric composite battery (MECB) from waste biomass and recycled materials that converts ambient humidity into continuous electrical output. The MECB integrates wild sugarcane fibers and recycled cigarette-butt cellulose with an upcycled carbon-paste layer, which enhances moisture uptake, ion dissociation, and directional ion migration across asymmetric current collectors. A single unit delivers up to 1.16 V and 16.44 µW cm⁻³, operates continuously in open environments, and self-restores voltage after drying via natural moisture reabsorption. A conceptual model establishes the moisture–electricity relationship, linking absorption to ion generation and power output. Scalable series/parallel configurations boost voltage and current, directly powering small electronics without external capacitors. This low-cost approach highlights moisture-activated textiles as sustainable, long-duration power sources for self-sufficient systems. Physical sciences/Energy science and technology Physical sciences/Engineering Earth and environmental sciences/Environmental sciences Physical sciences/Materials science Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Introduction Water is a sustainable and recyclable resource that plays a pivotal role in Earth’s energy dynamics through the natural hydrologic cycle. While energy harvesting from liquid water has been explored extensively, the vast potential of atmospheric moisture remains underutilized 1 , 2 . Hydrovoltaic power generation enables energy production by harvesting atmospheric water vapor in its gaseous state 3 . It directly generates electricity 4 via water-material interactions, provides enhanced flexibility, and complements conventional renewable energy sources 5 . The early development of hydrovoltaic power generation has progressed rapidly with a particular focus on droplets 6 , waves 7 , and water evaporation 8 . Moisture is a key component of the natural water cycle that acts as a medium for transferring thermal, mechanical, and chemical energy 9 . The use of low-dimensional nanostructures for harvesting moisture-induced energy presents a promising strategy to meet future energy demands through enhanced ionization and rapid ion transport 10 . Even recent investigations into moisture-material interactions have led to significant advancements in fields such as water splitting 11 . Recent study has employed hygroscopic hydrogels as water-absorbing electrolytes in conjunction with photoelectrochemical catalysts to facilitate moisture splitting 12 , 13 . Significant advancements have been made across emerging fields and applications 14 – 17 . For instance, optimizing the site-specific water binding properties of metal-organic frameworks (MOFs) has notably enhanced the efficiency of atmospheric water harvesting (AWH) 18 . Notably, moisture-driven electricity generation (MEG) has attracted significant attention in the past few years 2 . It utilizes streaming currents 4 , 19 – 21 or ion drift driven by concentration gradients 22 to convert the chemical energy of moisture into electrical energy. Many functional materials such as nanostructured carbon 4 , graphene 23 , carbon black 4 , metal oxide nanowires 24 , and proteins 25 have been utilized in MEG systems to efficiently harvest electrical energy from moisture. Natural hydrophilic substances 26 like lignocellulosic materials have emerged as valuable resources for constructing MEGs. Moreover, MEGs can be designed from organic or inorganic materials independently or through the integration of organic–inorganic composite nanomaterials 27 – 29 . However, these technologies face significant challenges. A major concern is the high cost of materials in MEG development, which could restrict large-scale implementation and reduce accessibility for end users. Moreover, the requirement for partial sealing complicates fabrication and limits design flexibility, and the spacing required between current collectors to sustain the moisture gradient can further increase internal resistance 2 . Conversion occurs only during water sorption 30 (33); if an MEG material or device is left exposed to an open environment when not in use, it ultimately becomes incapable of power generations 2 . Moisture-electric generators (MEGs) typically produce voltages of ≤ 0.6 V, which is insufficient for direct integration into wearable electronics and smart textile applications 31 . Thus, these limitations pose barriers to the development and application of MEG materials and devices. This research addresses these challenges by developing a MEG-based composite battery (MECB) that incorporates sustainable, cost-effective materials, increases scalability, simplifies fabrication processes, and improves energy generation efficiency to advance the practical application of MEG technologies. Materials and Methodology Engineering MEG-Based Composite Battery (MECB). To engineer the MECB, the composite structure was strategically designed to enhance power generation. The current collector was created on the surface of the composite. This structure comprises multiple functional layers in a planar configuration that enhance moisture-driven ion transport and electrical output while ensuring flexibility. Architecting the composite. The design of the composite was illustrated in Fig. 1 a. Lignocellulosic material such as Saccharum spontaneum (wild sugarcane or kans grass) was used for its relatively high moisture content and hydrophilic nature, which shows strong water affinity due to its polar structure. 32 This affinity allows efficient moisture uptake from the environment 33 , which is necessary for MEG. Wild sugarcane, categorized as a waste material due to natural dispersion of mature stalks (Supplementary Fig. 1), minimizes the composite cost. It was mixed with cigarette butt fibers (CBF), also considered waste material. Fibers were extracted from cigarette butts following a series of defined steps. (Supplementary Fig. 2) Cigarette butts were collected from bins, stores, and public spaces. They were manually cleaned of unburned tobacco and ash. The paper coating was removed with a blade, and the cellulose acetate filter was extracted and hand-shredded. Fibers were washed in hot water (70°C) for 30 minutes, then scoured and bleached with aqueous NaOH (99.9% purity) and H 2 O 2 (50% concentration) at 95°C for one hour 34 . Treated fibers were immersed in 0.02% H ₂ SO ₄ (100 ml) for 30 minutes at room temperature 35 , then rinsed several times with cold water. The fibers were cleaned using (99% purity) acetone and subsequently dried in an oven at 60°C for 60 minutes to remove heavy metal contaminants 34 . These purified fibers were integrated into the composite structure. A quadrilateral composite structure was fabricated by first preparing thin sheets from sequential layers of wild sugarcane fibers. A 100°C boiled 0.95 ml saline solution (sea salt and water) was sprayed on the sheet. (Supplementary Fig. 3) Then, cigarette butt fibers were arranged in a grid pattern of horizontal and vertical lines to form squares. (Supplementary Fig. 4) Again 0.95 ml of saline solution was applied. The second thin sheet of wild sugarcane fibers was layered, followed by a final saline spray. Polyvinyl acetate resin ((C 4 H 6 O 2 ) n ) was used as a binder to ensure cohesion. The composite was processed into thin sheets by felting process, thoroughly dried, and cut into quadrilateral shapes. Fabrication of permanent current collectors for the MECB. Current collectors play a vital role by enabling the effective collection and distribution of generated electricity, which enhances charge/discharge performance and provides structural support 36 . The positive current collector was fabricated on one side of the composite using a Carbon Black (CB)-Manganese Dioxide (MnO₂) mixture sourced from non-functional dry cell batteries, classified as e-waste. Carbon processed into porous CB provides a large surface area that is ideal for chemical binding which enhances reactions and improves absorption functionality 37 . Moreover, MnO₂ is a low-cost, abundant, and eco-friendly material with high capacitance for energy storage 38 . This CB - MnO₂ mixture is cost-effective and upcycling waste into higher-value products. Sea salt commonly known as sodium chloride (NaCl) was selected for its environmental stability and its ability to absorb up to 500% of its weight in moisture under high relative humidity conditions 2 . Thus, NaCl absorbs moisture under high RH (Supplementary Fig. 5). Although other hygroscopic salts like lithium chloride (LiCl) and calcium chloride (CaCl ₂ ) 39 were considered (Supplementary Fig. 6) but NaCl was selected for cost-effectiveness, high availability environmental safety, and optimal ionic activity. Moreover, experimental analysis further indicates that NaCl exhibits the fastest moisture uptake on the composites (Supplementary Fig. 7). The mixture of Carbon Black-MnO₂, sea salt, and water is termed the mixture-salt electrolyte solution. Due to its insolubility in saline water (Supplementary Fig. 8), minimal water is recommended for paste formation. The solution was applied to one side of the composites by brush coating. An initial conductivity of 1.37 × 10⁻⁷ S m⁻¹ was achieved at a 5.41 g m⁻² loading density, increasing to 1.0 × 10⁻⁶ S m⁻¹ at 9.46 g m⁻² after three times coating repetitions (Supplementary Fig. 9–10). Coated composites were thoroughly dried in oven at 70°C. Experimental evidence shows that the carbon-coated composite possesses enhanced moisture absorption and desorption behaviour relative to the uncoated composite, which is essential for effective moisture-driven energy conversion in MEG devices (Supplementary Fig. 11). Ultra-flexible aluminum foil collected from e-waste served as the negative collector to ensure cost efficiency and sustainability. It was collected and washed with detergent at 60°C for 30 minutes, then attached to the other side of the composite’s top surface using polyvinyl acetate. The entire structure was dried in oven at 70°C. The entire fabrication of the MECB is shown in Fig. 1 b, with a 3D schematic of the structural design presented in Fig. 1 c. Further characterization using scanning electron microscopy (SEM) revealed the fibrous architecture, coated surface of the composite (Fig. 1 d) and porous composition, while energy-dispersive X-ray spectroscopy (EDX) showed the elemental distribution of Na and Cl (Supplementary Fig. 12). Working Principle of the MECB. The battery operates through a hydrovoltaic mechanism that harnesses absorbed atmospheric moisture and facilitates ionic transport within the engineered composite (Supplementary Fig. 13). Upon exposure to RH, the composite absorbs moisture from the surrounding air. The absorbed water causes NaCl to dissociate into Na⁺ and Cl⁻ ions (Fig. 2 a) which follows the fundamental principles of electrolyte dissociation 40 . Ions move from regions of high concentration to low concentration. This movement occurs during moisture absorption, while ion backflow occurs during moisture desorption (Fig. 2 b). The transfer of ions from high to low concentration creates a potential difference that generates electrical energy (Fig. 2 c) between the current collectors 30 (Supplementary Fig. 14). Water plays dual roles as a medium for ionization and driver of ionic mobility. In hydrophilic materials, absorbed water forms ion transport pathways and enables ion movement essential for electric potential 41 . It also enhances surface interaction and maximizes area for effective MEG 42 . Density Functional Theory (DFT) 43 offers theoretical insight into this charge transfer mechanism 44 . Charges accumulate at the surface with pure water (0.0031e per H₂O molecule), but saline water (NaCl-embedded) shows result in a much higher charge transfer of 0.0189e, nearly six times greater 2 . In this study, NaCl ions embedded in the structure enhance surface charge during moisture absorption and thereby enable electricity generation. The CB embedded in the composite facilitates electric double layer (EDL) formation at electrode interfaces, increases charge separation, and stabilizes voltage output by adsorbing counter-ions 45 . The composite surface shows three RH-dependent regimes (Supplementary Fig. 15). At low RH, it remains dry and inactive because insufficient moisture prevents bond formation with NaCl. At 65% RH, moisture absorption supports ion mobility and EDL stability, which results in peak voltage efficiency but moderate power output due to limited current generation. At high RH, abundant moisture absorbed by the composite reacts with NaCl to form Na⁺ and Cl⁻ ions, that leads to higher current flow and greater overall power generation (Fig. 2 d and Supplementary Fig. 16). These regimes also appear through surface color variation (Supplementary Fig. 17). According to the Stern model 46 , the relationship between EDL surface charge density 2 and potential difference is defined. Water molecules dissociate into H⁺ and OH⁻ and increase surface charge density. NaCl provides Na⁺ ions that adsorb onto CB particles and increase charge separation 47 . Another key factor is the battery’s repeatable voltage generation cycle, regulated by the moisture absorption and desorption process 48 . Electrical signals appear only after moisture absorption which confirms ambient humidity as the energy source 49 . The system maintains stable performance within a defined RH range and delivers consistent energy output. It enables a sustainable closed-loop green energy source 48 (Supplementary Fig. 18). The interaction between water molecules and hygroscopic materials induces structural deformation, commonly observed as swelling (Supplementary Fig. 19) during moisture absorption and shrinking during desorption 50 . A defining characteristic of the MECB is its hygroscopic nature; at elevated RH, the composite rapidly absorbs water and becomes hydrated, whereas at reduced RH, it releases moisture and dehydrate (Supplementary Fig. 20). This behavior was also evident in the fully coated composite (Supplementary Fig. 21). The lignocellulosic and cellulose-based materials in the MECB are inherently hydrophilic, with polar groups like hydroxyl and carbonyl that adsorb water through hydrogen bonding 51 (Supplementary Fig. 22). This dynamic humidity response is critical for moisture-induced charge generation in the composite. Result and Discussion Electricity Generation of MECB. According to our observations, during moisture absorption, ion transport and water molecule ionization within the composite facilitate charge separation and thereby induce voltage and current generation (Supplementary Fig. 23). The MECB demonstrated varying open-circuit voltages (V oc ), with the highest recorded value of approximately 1.16 V. Additionally, the short-circuit current (I sc ) was measured in several microamperes (Fig. 3 a). Electrical output is observed only when two distinct current collectors are placed across the composite. No output is detected with connections in the same region which indicates the necessity of a water content gradient for electricity generation 2 . The distance between current collectors significantly impacts performance (Fig. 3 b). Voltage and current varies, and contact quality and local moisture output. Therefore, power generation efficiency depends strongly on the minimum distance between the two current collectors. The V oc of the MECB sustained different ranges over 9 days (216 hours) under varying temperature and humidity (Fig. 3 c). The I sc is also sustained over time across a range of current levels and varying temperature and humidity conditions (Fig. 3 d). These electrical responses indicate that the MECB continues to operate under ambient temperature and humidity conditions when exposed to an open environment for extended periods. It is noteworthy that the entire MECB remained exposed to an open humid environment throughout the long-term measurement and continued to operate even after full water absorption 30 , 52 (Fig. 3 e). Fundamentally, the absorbed water content controls the moisture gradient and influences overall MECB behavior. Water loss from external thermal stimuli reduces output, but prior MEG studies confirm functionality restoration via water reabsorption 2 . To investigate this, we examined MECB behavior under light exposure. A random full day (24 hours) was selected for experimental analysis. The V oc dropped significantly upon illumination but recovered after the light source was turned off (Fig. 3 f). This is attributed to the CB-MnO₂ mixture in the current collector, where CB functions as a photothermal material 53 . Another analysis shows that under rapid heating water desorption occurs faster than absorption during cooling and uptake remains slow at high temperature (Fig. 3 g). Another key observation is the mass of the composite affects MECB’s self-recharging behavior. When exposed to high heat, the battery dried completely and the voltage dropped sharply. Upon re-exposure to the natural environment, gradual moisture reabsorption occurred. During this period, the MECB showed a self-recharge effect (Fig. 2 h). These results confirm that MECB performance decreases with moisture loss and then returns to a self-recharge state as mass recovery occurs 54 . The regained moisture leads to progressive V oc recovery through natural adsorption and allows the MECB to accumulate electricity and sustainably harvest energy from environmental humidity (Fig. 2 i). To further understand the dynamic behavior of the MECB, time-resolved absorption and desorption experiments were conducted under controlled environmental conditions. Based on overall performance we selected two samples (Sample A and B) for analysis. During moisture absorption (MA%) I sc increased proportionally (Fig. 4 a and 4 b). In contrast, during moisture desorption (MD%) I sc decreased accordingly (Fig. 4 c and 4 d). However, V oc showed a nonlinear response to both MA% (Fig. 4 e and 4 f) and MD% (Fig. 4 g and 4 h). This formed an asymmetric bell-shaped trend that defines a critical hydration window where ion transport and interfacial polarization reach maximum efficiency. Excess moisture induced dielectric screening and caused a V oc drop. The faster rate of MA% compared with MD% in natural environments reflects rapid ionic activation from moisture influx, while the slower decline during desorption results from bound water retention and delayed ionic deactivation within the porous matrix. Time-resolved measurements show that current rises sharply during initial moisture contact and decays gradually during desorption (Supplementary Fig. 24). V oc peaks gradually and then fluctuates as the system approaches moisture equilibrium (Supplementary Fig. 25). Geometry Optimization for MECB Output. The preliminary observation in MECB was that a larger area exhibited an increase in output by enhancing I sc 2 . However, further investigation showed final power output depends more on ion transport efficiency and moisture distribution rather than total surface area. To validate this, four MECB samples with different surface areas but identical length, width, and thickness were fabricated (Fig. 5 a). Power Density was estimated as $$\:P=({V}_{oc}.{I}_{sc})/4(A.d)$$ 1 Where A is the projected area and d is thickness. Sample A showed the highest volumetric power density of approximately 16.44 µW cm⁻³ (Fig. 5 b) and a corresponding gravimetric power density of approximately 2.41 g cm⁻³ based on its density. Sample B showed the highest gravimetric power density of approximately 15.74 µW g⁻¹ (Supplementary Fig. 26) and it confirmed highest power output among all tested samples (Fig. 5 c) It showed a value approximately five times greater than that of the lowest-powered sample. (Supplementary Fig. 27) However, its volumetric power density was lower (≈ 5.1 µW cm⁻³). This contrast highlights the importance of balancing material efficiency per unit mass and total power output per unit volume in MECB. The optimal composite thickness increases voltage and current and produces superior power (Fig. 5 d). The structure lowers internal resistance and improves ion transport, which gives higher performance. Thus, careful geometric balancing is essential for improving MEG performance. A crucial factor is that MECB performance is entirely moisture-dependent. The generator operates as a fully moisture-driven energy harvesting system, where RH dynamically controls the internal water gradient. The results indicate that voltage output increases with RH, peaking at ≈ 65% and beyond 65%, V oc drops gradually (Fig. 5 e). The composite contains NaCl with a deliquescent RH of 75% at 25°C, allowing it to absorb significant moisture from the environment 55 . NaCl enhances ion transport by dissociating into Na⁺ and Cl⁻ and supports moisture uptake through its hygroscopic nature which boosts electrochemical potential and V oc output. In contrast to previously reported MEG systems, which typically required most specific environmental conditions and exhibited only transient electrical responses 8 , 56 . The MECB demonstrated better electrical performance across a wide range of temperatures and relative humidity levels (Fig. 5 f). This is attributed to the composite materials and hygroscopic salts, which help retain moisture and ensure stable voltage despite changes in environmental temperature 57 . However, extreme temperatures cause excess moisture loss which significantly reduces charge transport and voltage (Supplementary Fig. 28). RH variations regulate the internal water gradient and thereby influence ion mobility and overall charge transport efficiency. Normal temperatures allow better moisture absorption and further enhance MECB performance (Supplementary Fig. 29). Functional Integration and Application Prospects of the MECB. The MECB holds significant potential as an energy-harvesting and power-generation technology. Its production is cost-effective, as the entire system is fabricated using waste materials (Supplementary Fig. 30). This approach promotes upcycling while ensuring sustainability and efficient utilization of discarded resources. The MECB demonstrates outstanding mechanical flexibility and maintains superior voltage output under bending conditions (Fig. 6 a). Scaling up the MECB’s power output is achieved by series and parallel connection of multiple units, which respectively enhance V oc (Fig. 6 b) and I sc (Fig. 6 c and Supplementary Fig. 31). The series configuration uses sequential connection of MECB units and allows scalable voltage enhancement through cumulative ionic potential. This arrangement ensures structural simplicity and continuous electrical conduction. The highest V oc recorded for a single MECB was 1.16 V at 65% RH (Fig. 6 d). There are several modes of power output from the MECB. Storing the generated electricity in a capacitor is an effective way to make it accessible when required (Fig. 6 e). The MECB can also be used directly for energy supply (Fig. 6 f). Four MECBs were connected in series and self-charged through moisture absorption. At 30.5°C and 80% RH, the system generated 1.79 V and 323 µA, sufficient to illuminate a 3 mm red LED for over 3 hours (Supplementary Movie 1). This RH-dependent performance highlights its potential for passive humidity-responsive systems and long-duration micro-power applications. Unlike most previously reported moisture-induced generators that require capacitors 49 , the MECB directly powered the LED (Fig. 5 g). After the LED was turned off, post-discharge measurements showed a residual voltage of 1.70 V with no current under the same load conditions (Supplementary Fig. 32). By weight, the MECB delivers 1.52 V at 1.48 g and provides a strong balance between voltage and mass. In contrast conventional 1.5 V batteries like Olympic, Sunlight, Murata LR44 58 , and Enfuel Soft Battery 59 are significantly heavier. It offers a higher voltage-to-weight ratio making it well suited for lightweight wearable applications (Supplementary Table 1). Baqui's Moist Electric Generation Model (Baqui's MEG Model) The MEG systems integrate hydrophilic materials and hygroscopic salts. These components collectively enable moisture absorption, ion dissociation, and subsequent charge transfer which constitute the basis of MEG-based energy harvesting system. Given the fundamental role of these mechanisms, this study introduces a conceptual model, “Baqui’s Moist Electric Generation Model (Baqui’s MEG Model),” which mathematically describes the relationship between moisture absorption and electrical output. Baqui’s MEG Model States that, "In a system combining hydrophilic materials, hygroscopic salts, and moisture, an increase in moisture absorption leads to a proportional increase in ion generation, which in turn produces electrical energy when connected to conductive current collectors." This model describes the fundamental relationship between moisture absorption and power generation in MEG-based systems. Hydrophilic materials enhance atmospheric moisture absorption, while hygroscopic salts facilitate water dissociation into free ions. As moisture uptake increases, the concentration of dissociated ions rises proportionally, which enhances ion mobility and charge transport. When conductive current collectors are present, these mobile ions generate electrochemical potential and enable continuous charge flow. Mathematical Model for Baqui's MEG Model To establish a theoretical foundation for Baqui’s MEG Model, we propose a mathematical framework based on fundamental electrochemical principles. This model incorporates Fick’s Model of Diffusion 60 , the Nernst-Planck Eq. 6 1 , the Nernst Eq. 6 2 , and Ohm’s Model 63 . In a MEG system, moisture absorption by hydrophilic materials facilitates ion dissociation from hygroscopic salts and initiates ion movement. The flux of ions ( J ) is governed by Fick’s First Model of Diffusion 60 , expressed as: $$\:J=-D\frac{dc}{dx}$$ 1 Where J represents the ionic flux, D is the diffusion coefficient of ions, \(\:\frac{dC}{dx}\) denotes the concentration gradient of mobile ions across the material. The equation describes ion migration from high to low concentration regions driven by moisture-induced dissociation that leads to charge separation and electricity generation. As moisture absorption ( A ) increases, the ion concentration ( C ) within the system exhibits a proportional relationship, expressed as: $$\:C={k}_{A}A$$ 2 Where k A is a constant dependent on material hygroscopicity and salt dissociation efficiency. This relationship highlights that greater moisture uptake increases free ion availability which enhances ionic conductivity and supports charge transport. The rate of ion generation follows: $$\:\frac{dc}{dt}=\alpha\:A$$ 3 Here \(\:\frac{dC}{dt}\) represents the rate of change of ion concentration over time and α is a material-dependent coefficient that characterizes the efficiency of ion dissociation per unit of absorbed moisture. The equation illustrates that higher moisture absorption leads to a proportional increase in ion generation. This transport behavior is governed by the Nernst-Planck equation, expressed as: $$\:J=-D\frac{dc}{dx}+\mu\:CE$$ 4 where D is the ion diffusion coefficient, denotes the concentration gradient, µ is the ion mobility, C is the ion concentration, and E represents the applied electric field. The first term in Eq. 4 describes ion diffusion driven by concentration gradients as per Fick’s Model. The second term captures ion migration under an electric field which enhances directed charge transport. Furthermore, the generated voltage ( V ) is dictated by the ion concentration gradient across the system, as described by the Nernst equation: $$\:V=\frac{RT}{zf}\text{l}\text{n}\left(\frac{{C}_{out}}{{C}_{im}}\right)$$ 5 where R is the universal gas constant, T is the absolute temperature, z is the charge number of the ions, F is the Faraday constant, C out and C in are the ion concentrations at the two points (electrodes/current collectors). As moisture absorption increases, the higher ion concentration gradient strengthens the electrochemical potential and enhances the voltage output. The relationship between the V and A can be expressed as: $$\:V\propto\:\text{l}\text{n}\left(A\right)$$ 6 Here k V is a constant that includes material-specific factors. The equation indicates that V increases logarithmically with A as higher ion concentration enhances electrochemical potential. Besides, I generated is related to V and R (electrical resistance) of the material, based on Ohm's law which expressed as: $$\:I=\frac{V}{R}$$ 7 According to this relationship, for a given material, an increase in V will lead to an increase in the I generated, provided that the R remains constant. The system resistance R depends on ionic conductivity, geometry and ion transport efficiency. Increased A enhances conductivity which lowers resistance and boosts current output. The R is given by: $$\:R=\frac{L}{\sigma\:A}$$ 8 where L represents the length of the conductive path through the material, 𝜎 is the ionic conductivity, and A is the cross-sectional area through which the ions are transported. This relationship shows R decreases with higher ionic conductivity or cross-sectional area and increases with material length. As A increases ionic conductivity improves which reduces R and increases I as described by Ohm's Model (Eq. 7 ). Again, as A increases, the σ is directly proportional to A , which can be expressed as: $$\:\sigma\:\propto\:A$$ 9 Thus, the generated current I can be written as: $$\:I=\frac{kVln\left(A\right).k\sigma\:A}{L}$$ 10 where, k is a proportionality constant. Here, k σ reflects material properties including ion dissociation efficiency. The power output ( P ) of the system can be expressed as, $$\:P=VI$$ 11 Substituting the V and I from Equations ( 6 ) and ( 10 ), respectively, the power output becomes: $$\:P=\left(kVln\left(A\right)\right)\frac{kVk\sigma\:Aln\left(A\right)}{L}$$ 12 Simplifying, we get: $$\:P=\frac{{k}^{2}VK\sigma\:A{ln}^{2}\left(A\right)}{L}$$ 13 Finally, the derived model shows that the P is directly proportional to A with a logarithmic dependence, expressed as: $$\:P\propto\:A{ln}^{2}\left(A\right)$$ 14 This equation supports Baqui’s MEG Model by showing that increased moisture absorption increases ion concentration which enhances ionic conductivity and improves power output highlighting the key role of moisture in system performance. This behavior aligns with the fundamental principles of ion transport and electrochemical potential and also shows the importance of optimizing moisture absorption to maximize power output. Validation and Applicability of Baqui’s MEG Model To validate the proposed model that describes the relationship between moisture absorption and power generation, controlled experiments were conducted using MECB. The mathematical model states that the generated power output, P depends on the moisture absorption capacity, A by following the relationship: $$\:P=KA{ln}^{2}\left(A\right)$$ 15 This study experimentally evaluated this equation and found an R² value of 0.95. (Supplementary Table 2). This high coefficient confirms that the model captures power generation behavior with excellent accuracy. The experimental data and the theoretical curve align well across the entire moisture absorption range (Supplementary Fig. 33). The K value of 0.155 is a material-specific constant reflecting ion mobility, porosity, interfacial conductivity and internal moisture-driven potential gradients. The key consideration is that Baqui’s MEG model establishes a broadly applicable theoretical framework for understanding moisture-electric generation. Beyond our system, we qualitatively aligned the model with trends from previous MEG devices. While the equation links moisture absorption to power output, earlier studies often correlate power output with relative humidity (RH%) or RH and voltage/current. (Supplementary Fig. 34). However, as RH rises, moisture absorption by materials increases proportionally 64 due to the greater uptake by hydrophilic and hygroscopic materials, particularly at high RH. Our experimental data (Supplementary Table 3) further confirm RH as a reliable indicator of moisture absorption across diverse MEG platforms. However, MEG systems vary in material properties, fabrication methods, structure and measurement conditions. Despite these differences, our equation aligns with trends in previous MEG studies showing that power output rises with absorbed moisture of its natural logarithm. This confirms that moisture enhances electricity generation through a nonlinear effect. These results suggest Baqui’s MEG Model provides a robust and general framework for understanding moisture-induced electricity generation across diverse materials and device designs. Conclusion In summary, we have successfully developed an innovative MECB by engineering a multifunctional composite structure from waste-derived materials. The MECB exhibits robust and repeatable energy output driven by moisture-induced ion transport under ambient humidity. The integration of wild sugarcane and recycled cigarette butt fibers with a salt-based electrolyte derived from e-waste enables the fabrication of a flexible and scalable green energy-harvesting device. A functional imbalance created by different current collectors sustains voltage output even after full moisture saturation. The system remained operational under extended open-environment conditions and exhibited a self-regenerating behavior through dynamic desorption and absorption cycles. A single MECB achieved highest 1.16 V open-circuit voltage and 16.44 µW cm⁻³ power density. The connection of multiple MECB units in series or parallel enhances the energy output and offers a scalable strategy for long-duration and low-power applications. We compared the performance with previous MEGs and found that MECB demonstrates comparatively improved efficiency. (Supplementary Table 4) We also propose ‘Baqui’s Moist Electric Generation Model’ as a fundamental framework that links moisture absorption, ion dissociation, and electricity generation to guide future MEG system design. These findings highlight both practical viability and deeper insights into moisture–material interactions for next-generation energy system. Declarations Data availability All data supporting the findings of this study are available within the Source Data file and the Supplementary Information associated with this article. Author contributions These authors contributed equally: Aman Ul Azam Khan and Nazmunnahar Nazmunahar. A.U.A.K. and N.N. designed the experiments and prepared the original draft. M.H. performed the theoretical calculations and conducted the data analysis. All authors discussed the results and contributed to manuscript revision. A.B. supervised the overall project. Corresponding authors: Nazmunnahar Nazmunnahar Competing interests The authors declare no competing interests. Funding Declaration This research received no external funding. References Guan, P. et al. Recent development of moisture-enabled‐electric nanogenerators. Small 18 , 2204603 (2022). Zhang, Y. et al. An asymmetric hygroscopic structure for moisture-driven hygro‐ionic electricity generation and storage. Adv. Mater. 34 , 2201228 (2022). Xie, J. W., Chen, L., Yang, X., Wu, P. & Huang, F. (2019). Yuelong. (IntechOpen. Xue, G. et al. Water-evaporation-induced electricity with nanostructured carbon materials. Nat. Nanotechnol. 12 , 317–321 (2017). Soares, P. Electrical energy generation through water evaporation using porous membranes (Universidade do Porto (Portugal), 2023). Yin, J. et al. Generating electricity by moving a droplet of ionic liquid along graphene. Nat. Nanotechnol. 9 , 378–383 (2014). Yin, J. et al. Waving potential in graphene. Nat. Commun. 5 , 3582 (2014). Huang, Y. et al. All-region-applicable, continuous power supply of graphene oxide composite. Energy Environ. Sci. 12 , 1848–1856 (2019). Fu, C. et al. A Long Life Moisture-Enabled Electric Generator Based on Ionic Diode Rectification and Electrode Chemistry Regulation. Adv. Sci. 11 , 2305530 (2024). Huang, Y. et al. Interface-mediated hygroelectric generator with an output voltage approaching 1.5 volts. Nat. Commun. 9 , 4166 (2018). Zhang, Y., Nandakumar, D. K. & Tan, S. C. Digestion of ambient humidity for energy generation. Joule 4 , 2532–2536 (2020). Nandakumar, D. K., Vaghasiya, J. V., Yang, L., Zhang, Y. & Tan, S. C. A solar cell that breathes in moisture for energy generation. Nano Energy . 68 , 104263 (2020). Yang, L. et al. Energy harvesting from atmospheric humidity by a hydrogel-integrated ferroelectric-semiconductor system. Joule 4 , 176–188 (2020). Li, X. et al. Metalized polyamide heterostructure as a moisture-responsive actuator for multimodal adaptive personal heat management. Sci. Adv. 7 , eabj7906 (2021). Ejeian, M. & Wang, R. Adsorption-based atmospheric water harvesting. Joule 5 , 1678–1703 (2021). Lord, J. et al. Global potential for harvesting drinking water from air using solar energy. Nature 598 , 611–617 (2021). Yang, J. et al. A moisture-hungry copper complex harvesting air moisture for potable water and autonomous urban agriculture. Adv. Mater. 32 , 2002936 (2020). Hanikel, N. et al. Evolution of water structures in metal-organic frameworks for improved atmospheric water harvesting. Science 374 , 454–459 (2021). van der Heyden, F. H., Stein, D. & Dekker, C. Streaming currents in a single nanofluidic channel. Phys. Rev. Lett. 95 , 116104 (2005). Van der Heyden, F. H., Stein, D., Besteman, K., Lemay, S. G. & Dekker, C. Charge inversion at high ionic strength studied by streaming currents. Phys. Rev. Lett. 96 , 224502 (2006). Joly, L., Ybert, C., Trizac, E. & Bocquet, L. Hydrodynamics within the electric double layer on slipping surfaces. Phys. Rev. Lett. 93 , 257805 (2004). Zhao, F., Cheng, H., Zhang, Z., Jiang, L. & Qu, L. Direct power generation from a graphene oxide film under moisture. Adv. Mater. (Deerfield Beach Fla) . 27 , 4351–4357 (2015). Zhao, F., Liang, Y., Cheng, H., Jiang, L. & Qu, L. Highly efficient moisture-enabled electricity generation from graphene oxide frameworks. Energy Environ. Sci. 9 , 912–916 (2016). Shen, D. et al. Self-powered wearable electronics based on moisture enabled electricity generation. Adv. Mater. 30 , 1705925 (2018). Mandal, S. et al. Protein-based flexible moisture-induced energy-harvesting devices as self-biased electronic sensors. ACS Appl. Electron. Mater. 2 , 780–789 (2020). Kwon, S. H. et al. An effective energy harvesting method from a natural water motion active transducer. Energy Environ. Sci. 7 , 3279–3283 (2014). Kalia, S., Kaith, B. & Kaur, I. Pretreatments of natural fibers and their application as reinforcing material in polymer composites—a review. Polym. Eng. Sci. 49 , 1253–1272 (2009). Spitalsky, Z., Tasis, D., Papagelis, K. & Galiotis, C. Carbon nanotube–polymer composites: chemistry, processing, mechanical and electrical properties. Prog. Polym. Sci. 35 , 357–401 (2010). Günther, A. & Jensen, K. F. Multiphase microfluidics: from flow characteristics to chemical and materials synthesis. Lab. Chip . 6 , 1487–1503 (2006). Xu, T. et al. An efficient polymer moist-electric generator. Energy Environ. Sci. 12 , 972–978 (2019). Khan, A. U. A. et al. Development of the smart jacket featured with medical, sports, and defense attributes using conductive thread and thermoelectric fabric. Engineering Proceedings 30, 18 (2023). Rahman, M., Das, A., Tabassum, S., Das, S. & Uddin, M. Physical and chemical characterization of Saccharum spontaneum flower fibre: potential applications in thermal insulation and microbial fuel cells. arXiv preprint arXiv:2501.05324 (2025). Al-Maharma, A. Y. & Al-Huniti, N. Critical review of the parameters affecting the effectiveness of moisture absorption treatments used for natural composites. J. Compos. Sci. 3 , 27 (2019). Afroz, F., Mahmud, R. U. & Islam, R. Green approach to recover the cellulose acetate fiber from used cigarette butts, and characterize the filter fiber. AATCC J. Res. 10 , 311–320 (2023). Benavente, M. J., Caballero, M. J. A., Silvero, G., López-Coca, I. & Escobar, V. G. in Proceedings. (MDPI). Yamada, M., Watanabe, T., Gunji, T., Wu, J. & Matsumoto, F. Review of the design of current collectors for improving the battery performance in lithium-ion and post-lithium-ion batteries. Electrochem 1 , 124–159 (2020). Tian, W. et al. Porous carbons: structure-oriented design and versatile applications. Adv. Funct. Mater. 30 , 1909265 (2020). Rupnar, D. V. et al. Recent trends and advances in MnO2-based energy storage technologies. Inorg. Chem. Commun. 173 , 113784 (2025). Shan, H. et al. Hygroscopic salt-embedded composite materials for sorption-based atmospheric water harvesting. Nat. Reviews Mater. 9 , 699–721 (2024). Crundwell, F. K. The impact of surface charge on the ionic dissociation of common salt (NaCl). Chem. Eng. Sci. 205 , 174–180 (2019). Okada, T. et al. Ion and water transport characteristics of Nafion membranes as electrolytes. Electrochim. Acta . 43 , 3741–3747 (1998). Feng, J. C. et al. High output power moist-electric generator based on synergistic nanoarchitectonics for effective ion regulation. Nano Energy . 119 , 109103 (2024). Feng, D. et al. Catalytic mechanism of Na on coal pyrolysis-derived carbon black formation: Experiment and DFT simulation. Fuel Process. Technol. 224 , 107011 (2021). Bahari, Y., Mortazavi, B., Rajabpour, A., Zhuang, X. & Rabczuk, T. Application of two-dimensional materials as anodes for rechargeable metal-ion batteries: A comprehensive perspective from density functional theory simulations. Energy Storage Mater. 35 , 203–282 (2021). Frackowiak, E., Abbas, Q. & Béguin, F. Carbon/carbon supercapacitors. J. Energy Chem. 22 , 226–240 (2013). Brown, M. A., Goel, A. & Abbas, Z. Effect of electrolyte concentration on the stern layer thickness at a charged interface. Angew. Chem. 128 , 3854–3858 (2016). Rasines, G. et al. On the use of carbon black loaded nitrogen-doped carbon aerogel for the electrosorption of sodium chloride from saline water. Electrochim. Acta . 170 , 154–163 (2015). Wang, H. et al. Moisture adsorption-desorption full cycle power generation. Nat. Commun. 13 , 2524 (2022). Sun, Z. et al. Emerging design principles, materials, and applications for moisture-enabled electric generation. EScience 2 , 32–46 (2022). Li, Y. & Tanaka, T. Kinetics of swelling and shrinking of gels. J. Chem. Phys. 92 , 1365–1371 (1990). Etale, A., Onyianta, A. J., Turner, S. R. & Eichhorn, S. J. Cellulose: a review of water interactions, applications in composites, and water treatment. Chem. Rev. 123 , 2016–2048 (2023). Liu, X. et al. Power generation from ambient humidity using protein nanowires. Nature 578 , 550–554 (2020). Han, D., Meng, Z., Wu, D., Zhang, C. & Zhu, H. Thermal properties of carbon black aqueous nanofluids for solar absorption. Nanoscale Res. Lett. 6 , 457 (2011). Yan, H., Liu, Z. & Qi, R. Development and mechanism investigation of TiO2/Co hydrogel microgenerator utilizing humidity gradient. Energy. Conv. Manag. 291 , 117256 (2023). Biskos, G., Malinowski, A., Russell, L., Buseck, P. & Martin, S. Nanosize effect on the deliquescence and the efflorescence of sodium chloride particles. Aerosol Sci. Technol. 40 , 97–106 (2006). Cheng, H. et al. Spontaneous power source in ambient air of a well-directionally reduced graphene oxide bulk. Energy Environ. Sci. 11 , 2839–2845 (2018). Xu, J. et al. Ultrahigh solar-driven atmospheric water production enabled by scalable rapid-cycling water harvester with vertically aligned nanocomposite sorbent. Energy Environ. Sci. 14 , 5979–5994 (2021). Brinkley, S. Top Picks for LR44 Battery Equivalents , < (2023). https://www.ovaga.com/blog/fast-charging-technology/top-picks-for-lr44-battery-equivalents#simple-list-item-0 Oy, E. SoftBattery®: Printed Thin and Flexible Battery Solutions , < https://www.enfucell.com/softbattery (. Paul, A., Laurila, T., Vuorinen, V. & Divinski, S. V. in Thermodynamics, diffusion and the kirkendall effect in solids 115–139Springer, (2014). Maex, R. On the nernst–planck equation. J. Integr. Neurosci. 16 , 73–91 (2017). Feiner, A. S. & McEvoy, A. The nernst equation. J. Chem. Educ. 71 , 493 (1994). Tenny, K. M. & Keenaghan, M. Ohms Law. (2017). Li, Y. & Ren, S. 2-Basic properties of building decorative materials. Building Decor. Materials , 10–24 (2011). Additional Declarations No competing interests reported. Supplementary Files MEGSupplementaryDocument.docx SupplementaryMovie1.mp4 SourceDataofMECB.xlsx Cite Share Download PDF Status: Under Revision Version 1 posted Editorial decision: Revision requested 30 Jan, 2026 Reviews received at journal 29 Jan, 2026 Reviewers agreed at journal 23 Jan, 2026 Reviews received at journal 22 Jan, 2026 Reviewers agreed at journal 22 Jan, 2026 Reviewers invited by journal 16 Jan, 2026 Editor invited by journal 16 Jan, 2026 Editor assigned by journal 12 Jan, 2026 Submission checks completed at journal 12 Jan, 2026 First submitted to journal 10 Jan, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8570579","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":576424425,"identity":"09443f3f-43bd-496b-aca1-16f04aa49e93","order_by":0,"name":"Aman Ul Azam Khan","email":"","orcid":"","institution":"BGMEA University of Fashion \u0026 Technology","correspondingAuthor":false,"prefix":"","firstName":"Aman","middleName":"Ul Azam","lastName":"Khan","suffix":""},{"id":576424426,"identity":"ea2f9a2f-f770-4713-a6ee-069f25447e81","order_by":1,"name":"Nazmunnahar Nazmunnahar","email":"data:image/png;base64,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","orcid":"","institution":"The University of Manchester","correspondingAuthor":true,"prefix":"","firstName":"Nazmunnahar","middleName":"","lastName":"Nazmunnahar","suffix":""},{"id":576424427,"identity":"4e164d21-1492-427e-acde-ed7d03651255","order_by":2,"name":"Mortuza Hasan","email":"","orcid":"","institution":"BGMEA University of Fashion \u0026 Technology","correspondingAuthor":false,"prefix":"","firstName":"Mortuza","middleName":"","lastName":"Hasan","suffix":""},{"id":576424428,"identity":"03fab29a-636d-47c3-a848-ca5b0b4287dd","order_by":3,"name":"Abdul Baqui","email":"","orcid":"","institution":"Central Queensland University (CQU)","correspondingAuthor":false,"prefix":"","firstName":"Abdul","middleName":"","lastName":"Baqui","suffix":""}],"badges":[],"createdAt":"2026-01-10 21:53:16","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8570579/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8570579/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":100688126,"identity":"52d6670a-9bdc-488a-8869-645e6ec2b831","added_by":"auto","created_at":"2026-01-20 13:26:38","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":2371251,"visible":true,"origin":"","legend":"","description":"","filename":"ManusciptofMECBV2.docx","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/73095aee08187de5eb912496.docx"},{"id":100688199,"identity":"d30cd115-e5e8-4d2f-94fd-1d0d11d33a91","added_by":"auto","created_at":"2026-01-20 13:29:23","extension":"json","order_by":1,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":5840,"visible":true,"origin":"","legend":"","description":"","filename":"1559c244b1704536a0554c87fcfb5f69.json","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/7193d087779c544b19913f1f.json"},{"id":100688146,"identity":"feac899f-6163-440e-985f-a51b4a164865","added_by":"auto","created_at":"2026-01-20 13:26:56","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":7960408,"visible":true,"origin":"","legend":"","description":"","filename":"MEGSupplementaryDocument.docx","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/32c58d4de2af341164ebe2c4.docx"},{"id":100688135,"identity":"665d2682-704a-4e19-99a1-5c85b3648f06","added_by":"auto","created_at":"2026-01-20 13:26:55","extension":"xlsx","order_by":3,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":64703,"visible":true,"origin":"","legend":"","description":"","filename":"SourceDataofMECB.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/fa19217095c7347069f494bf.xlsx"},{"id":100688128,"identity":"b83b0300-b32e-4cc2-96c7-1af55a65c26f","added_by":"auto","created_at":"2026-01-20 13:26:49","extension":"mp4","order_by":4,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":44289098,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMovie1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/eb13bce06078bf06194a6219.mp4"},{"id":100688176,"identity":"7784b7ef-8e20-48a7-b192-c85fd6d16cb2","added_by":"auto","created_at":"2026-01-20 13:28:19","extension":"xml","order_by":5,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":132829,"visible":true,"origin":"","legend":"","description":"","filename":"1559c244b1704536a0554c87fcfb5f691enriched.xml","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/d4653811895df97a852674f6.xml"},{"id":100688243,"identity":"eb8cdd04-fb19-4157-bc3d-14f3a0f54159","added_by":"auto","created_at":"2026-01-20 13:30:24","extension":"png","order_by":6,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":815321,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/30f35341597ad0eec2a29102.png"},{"id":100688044,"identity":"4e309524-fb39-44f1-8b53-a2fa2d541ed1","added_by":"auto","created_at":"2026-01-20 13:25:36","extension":"png","order_by":7,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":411824,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/cd02acaae3e77ecea8808f77.png"},{"id":100687986,"identity":"1a181026-b419-4cde-ae2f-ce31c44df038","added_by":"auto","created_at":"2026-01-20 13:24:26","extension":"png","order_by":8,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":391102,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/8cb40c7bba30b7bcc975ee6b.png"},{"id":100688201,"identity":"f85d267b-ded0-45bb-8290-c21214438a92","added_by":"auto","created_at":"2026-01-20 13:29:26","extension":"png","order_by":9,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":90756,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/a4b46b7e26c85949d4cc2f85.png"},{"id":100688134,"identity":"dbcfbb92-b7db-4436-9187-912da68df294","added_by":"auto","created_at":"2026-01-20 13:26:54","extension":"png","order_by":10,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":173755,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/070b3e98d389b7929650c13d.png"},{"id":100688053,"identity":"036c6c5b-df0a-4634-972f-db578bd20834","added_by":"auto","created_at":"2026-01-20 13:25:59","extension":"png","order_by":11,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":469736,"visible":true,"origin":"","legend":"","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/49c900eee51122d0dcab3202.png"},{"id":100688175,"identity":"517a0644-9b47-4050-a49d-f306e6f39ee7","added_by":"auto","created_at":"2026-01-20 13:28:17","extension":"png","order_by":12,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":93328,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/b1e6b1c50ea7b5f1d2cd95c1.png"},{"id":100688198,"identity":"4e812fad-79d7-4358-8f7d-9aad2c51c286","added_by":"auto","created_at":"2026-01-20 13:28:50","extension":"png","order_by":13,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":63774,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/4f9beb3188a8318e4c1215f4.png"},{"id":100688006,"identity":"f4b6948a-602f-4b03-be09-d9078a2579b1","added_by":"auto","created_at":"2026-01-20 13:25:17","extension":"png","order_by":14,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":59682,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/3d3a2f35fbd2a5f833ed37b0.png"},{"id":100688158,"identity":"ccb226b5-2eaa-4b4c-b2ab-383317d6342b","added_by":"auto","created_at":"2026-01-20 13:27:40","extension":"png","order_by":15,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":21864,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/2a3d0d3a6c5ff5af619b2ba3.png"},{"id":100688203,"identity":"58778e9a-9cf8-4b74-849e-03a3d0610cb0","added_by":"auto","created_at":"2026-01-20 13:29:38","extension":"png","order_by":16,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":31310,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/60d646cd56e9d8491707b16e.png"},{"id":100688161,"identity":"f62be4f7-a61e-4a50-a140-bfc8361cb224","added_by":"auto","created_at":"2026-01-20 13:27:51","extension":"png","order_by":17,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":74374,"visible":true,"origin":"","legend":"","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/1f871e30c425cf57abc2e0e8.png"},{"id":100688051,"identity":"2ed662d7-5814-49fc-a244-019fdf95f91c","added_by":"auto","created_at":"2026-01-20 13:25:53","extension":"xml","order_by":18,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":132785,"visible":true,"origin":"","legend":"","description":"","filename":"1559c244b1704536a0554c87fcfb5f691structuring.xml","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/f43c2561205d4cf6af96bc6d.xml"},{"id":100688150,"identity":"8cc615f4-abc3-4ecf-bf6f-eac37d1d9515","added_by":"auto","created_at":"2026-01-20 13:27:07","extension":"html","order_by":19,"title":"","display":"","copyAsset":false,"role":"acdc-reference","size":148348,"visible":true,"origin":"","legend":"","description":"","filename":"earlyproof.html","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/79b343b35fd3c95dace9a61c.html"},{"id":100688202,"identity":"13b75f37-209a-429e-a249-17145c838981","added_by":"auto","created_at":"2026-01-20 13:29:27","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":399757,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eDesign and structure of the MECB.\u003c/strong\u003e \u003cstrong\u003ea\u003c/strong\u003e Schematic of the composite architecture comprising wild Saccharum spontaneum (Wild Sugercane) and cigarette-butt fibers (CBF). \u003cstrong\u003eb\u003c/strong\u003e3D symmetric representation of the structural sequence and fabrication of the MECB. \u003cstrong\u003ec\u003c/strong\u003e 3D schematic overall structure of the MECB. \u003cstrong\u003ed\u003c/strong\u003e SEM micrographs of the coating surface and internal porous structure showing interwoven fibers (CBF and wild sugarcane) and carbon coating that facilitates moisture absorption and ion transport.\u003c/p\u003e","description":"","filename":"floatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/c811bd70697c589650ec1b03.png"},{"id":100688160,"identity":"1d147323-3bda-43ce-b6b8-abdd40e59077","added_by":"auto","created_at":"2026-01-20 13:27:51","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":333879,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eWorking mechanism of the MECB driven by moisture interaction.\u003c/strong\u003e \u003cstrong\u003ea \u003c/strong\u003eDissolution of crystal NaCl salt in absorbed water leading to Na⁺ and Cl⁻ formation and hydration. \u003cstrong\u003eb\u003c/strong\u003e Illustration of directional ion migration and backflow during moisture absorption and desorption, highlighting the reversible hygro-ionic process. \u003cstrong\u003ec\u003c/strong\u003e Conversion of chemical potential energy to electrical energy \u003cstrong\u003ed \u003c/strong\u003eSchematic representation of ion migration and ion backflow in the MECB during moisture absorption and desorption under low, moderate, and high relative humidity (RH) conditions.\u003c/p\u003e","description":"","filename":"floatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/a02e74a43133e0c06ad61785.png"},{"id":100688155,"identity":"d85ba3c4-7a09-4c32-bd50-5347076aff16","added_by":"auto","created_at":"2026-01-20 13:27:28","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":444155,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eElectricity generation characteristics of the MECB.\u003c/strong\u003e \u003cstrong\u003ea \u003c/strong\u003eOpen-circuit voltage (V\u003csub\u003eoc\u003c/sub\u003e) and short-circuit current (I\u003csub\u003e\u003cstrong\u003esc\u003c/strong\u003e\u003c/sub\u003e) generation of the different sample types. \u003cstrong\u003eb\u003c/strong\u003e Effect of the distance between current collectors on electricity generation. \u003cstrong\u003ec\u003c/strong\u003e Continuous measurement of V\u003csub\u003eoc\u003c/sub\u003e and \u003cstrong\u003ed\u003c/strong\u003e I\u003csub\u003esc\u003c/sub\u003e under open environmental conditions for 216 h (9 days). \u003cstrong\u003ee\u003c/strong\u003e Relationship between V\u003csub\u003eoc\u003c/sub\u003e and fractional water uptake which shows an asymmetric dependence with an optimum hydration point. \u003cstrong\u003ef\u003c/strong\u003e Voltage variation of a single MECB over a 24 h period under ambient conditions. \u003cstrong\u003eg\u003c/strong\u003e Effect of rapid heating that causes water desorption and slower reabsorption during cooling state \u003cstrong\u003eh\u003c/strong\u003e Mass variation of the MECB during the self-recharging state. \u0026nbsp;\u003cstrong\u003ei\u003c/strong\u003e Accumulated charge stored in a 4,700 µF capacitor connected to a single MECB, confirming successive charge-discharge cycles.\u003c/p\u003e","description":"","filename":"floatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/07a4d9f9076fc71ae36d185a.png"},{"id":100688130,"identity":"71986259-5f47-407b-b896-38f1f2979cc8","added_by":"auto","created_at":"2026-01-20 13:26:50","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":167593,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCorrelation between moisture and electrical performance of the MECB. a\u003c/strong\u003e Relationship between current (I\u003csub\u003esc\u003c/sub\u003e) generation and moisture absorption (MA%) for Sample A. and \u003cstrong\u003eb\u003c/strong\u003e Sample B. \u003cstrong\u003ec\u003c/strong\u003e Decrease in I\u003csub\u003esc\u003c/sub\u003e with moisture desorption (MD%) for Sample A and \u003cstrong\u003ed\u003c/strong\u003e Sample B. \u003cstrong\u003ee \u003c/strong\u003eAsymmetric dependence of open-circuit voltage (V\u003csub\u003eoc\u003c/sub\u003e) on MA% for Sample A and \u003cstrong\u003ef\u003c/strong\u003e Sample B. \u003cstrong\u003eg\u003c/strong\u003e Correlation between V\u003csub\u003eoc\u003c/sub\u003e and MD% for Sample A and \u003cstrong\u003eh\u003c/strong\u003e Sample B, demonstrating the strong coupling between hygroscopic behavior and electrical response.\u003c/p\u003e","description":"","filename":"floatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/0360ad3c911cfba061a90a27.png"},{"id":100688248,"identity":"42cf894c-8c00-494e-80ec-eb45934d99c3","added_by":"auto","created_at":"2026-01-20 13:30:38","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":233175,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eGeometry optimization for enhanced MECB output performance. a\u003c/strong\u003e Illustration of four MECB configurations (Samples A, B, C and D) with different length, width, and surface area. \u003cstrong\u003eb\u003c/strong\u003e Volumetric power density of each sample plotted as a function of geometric area. \u003cstrong\u003ec\u003c/strong\u003e Power output of MECBs with different sizes. \u003cstrong\u003ed\u003c/strong\u003e Influence of composite thickness on open-circuit voltage (V\u003csub\u003eoc\u003c/sub\u003e) and short-circuit current (I\u003csub\u003esc\u003c/sub\u003e). \u003cstrong\u003ee\u003c/strong\u003e Electrical performance of the MECB under varying relative humidity (RH) conditions. \u003cstrong\u003ef\u003c/strong\u003e Effect of environmental factors, including humidity and temperature, on electricity generation efficiency.\u003c/p\u003e","description":"","filename":"floatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/2c55a60d640e080c2e7c0505.png"},{"id":100688246,"identity":"2f4325b0-428b-4554-884e-fb029d16c8a3","added_by":"auto","created_at":"2026-01-20 13:30:29","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":316131,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003ePerformance and integration of MECB units for energy storage and device power. a\u003c/strong\u003e V\u003csub\u003eoc\u003c/sub\u003e stability under mechanical deformation. \u003cstrong\u003eb\u003c/strong\u003e V\u003csub\u003eoc\u003c/sub\u003e output versus the number of serially connected MECB units. The inset is serial circuit. \u003cstrong\u003ec\u003c/strong\u003e I\u003csub\u003esc\u003c/sub\u003e output for parallel configurations. The inset is parallel circuit. \u003cstrong\u003ed\u003c/strong\u003e Highest V\u003csub\u003eoc\u003c/sub\u003e recorded from a single MECB. \u003cstrong\u003ee\u003c/strong\u003e Capacitor-charging performance of the MECB. A single MECB connected to a 47 µF capacitor shows rapid charge storage and prolonged retention. \u003cstrong\u003ef\u003c/strong\u003e Direct powering of a red LED using four MECB units connected in series. \u003cstrong\u003eg\u003c/strong\u003e Continuous LED illumination powered by the MECB. Continuous LED illumination over three hours reflects the practical capability of the MECB for self-sustained energy supply.\u003c/p\u003e","description":"","filename":"floatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/605968323495c6253bb5ab5b.png"},{"id":100804017,"identity":"b7bb1408-f932-488c-96a0-40e80eebafaa","added_by":"auto","created_at":"2026-01-21 14:34:52","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2913905,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/bb6cdb09-57d8-4f1b-9ce5-e53c94238b6c.pdf"},{"id":100687977,"identity":"ba4fb91c-25fe-4243-83f9-f0ce3512ca23","added_by":"auto","created_at":"2026-01-20 13:24:12","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":7960408,"visible":true,"origin":"","legend":"","description":"","filename":"MEGSupplementaryDocument.docx","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/e45e5de06a0fd9a500dedb41.docx"},{"id":100688102,"identity":"5d8570d9-9b1d-4e07-af04-235e811bf8c5","added_by":"auto","created_at":"2026-01-20 13:26:30","extension":"mp4","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":44289098,"visible":true,"origin":"","legend":"","description":"","filename":"SupplementaryMovie1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/3faf100295eadcb115066d9b.mp4"},{"id":100687984,"identity":"8326f013-67cc-40c9-8b09-c8754c060f20","added_by":"auto","created_at":"2026-01-20 13:24:25","extension":"xlsx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":64703,"visible":true,"origin":"","legend":"","description":"","filename":"SourceDataofMECB.xlsx","url":"https://assets-eu.researchsquare.com/files/rs-8570579/v1/502640dcad7d2be4dd549ac3.xlsx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Moisture-driven Composite Battery from Waste Materials for Sustainable Energy Harvesting","fulltext":[{"header":"Introduction","content":"\u003cp\u003eWater is a sustainable and recyclable resource that plays a pivotal role in Earth\u0026rsquo;s energy dynamics through the natural hydrologic cycle. While energy harvesting from liquid water has been explored extensively, the vast potential of atmospheric moisture remains underutilized\u003csup\u003e\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e,\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Hydrovoltaic power generation enables energy production by harvesting atmospheric water vapor in its gaseous state\u003csup\u003e\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u003c/sup\u003e. It directly generates electricity\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e via water-material interactions, provides enhanced flexibility, and complements conventional renewable energy sources\u003csup\u003e\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThe early development of hydrovoltaic power generation has progressed rapidly with a particular focus on droplets\u003csup\u003e\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u003c/sup\u003e, waves\u003csup\u003e\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u003c/sup\u003e, and water evaporation\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u003c/sup\u003e. Moisture is a key component of the natural water cycle that acts as a medium for transferring thermal, mechanical, and chemical energy\u003csup\u003e\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u003c/sup\u003e. The use of low-dimensional nanostructures for harvesting moisture-induced energy presents a promising strategy to meet future energy demands through enhanced ionization and rapid ion transport\u003csup\u003e\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e\u003c/sup\u003e. Even recent investigations into moisture-material interactions have led to significant advancements in fields such as water splitting\u003csup\u003e\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e\u003c/sup\u003e. Recent study has employed hygroscopic hydrogels as water-absorbing electrolytes in conjunction with photoelectrochemical catalysts to facilitate moisture splitting\u003csup\u003e\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e,\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e\u003c/sup\u003e. Significant advancements have been made across emerging fields and applications\u003csup\u003e\u003cspan additionalcitationids=\"CR15 CR16\" citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e\u003c/sup\u003e. For instance, optimizing the site-specific water binding properties of metal-organic frameworks (MOFs) has notably enhanced the efficiency of atmospheric water harvesting (AWH)\u003csup\u003e\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eNotably, moisture-driven electricity generation (MEG) has attracted significant attention in the past few years\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. It utilizes streaming currents\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e,\u003cspan additionalcitationids=\"CR20\" citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u003c/sup\u003e or ion drift driven by concentration gradients\u003csup\u003e\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e\u003c/sup\u003e to convert the chemical energy of moisture into electrical energy. Many functional materials such as nanostructured carbon\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e, graphene\u003csup\u003e\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u003c/sup\u003e, carbon black\u003csup\u003e\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u003c/sup\u003e, metal oxide nanowires\u003csup\u003e\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u003c/sup\u003e, and proteins\u003csup\u003e\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e\u003c/sup\u003e have been utilized in MEG systems to efficiently harvest electrical energy from moisture. Natural hydrophilic substances\u003csup\u003e\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u003c/sup\u003e like lignocellulosic materials have emerged as valuable resources for constructing MEGs. Moreover, MEGs can be designed from organic or inorganic materials independently or through the integration of organic\u0026ndash;inorganic composite nanomaterials\u003csup\u003e\u003cspan additionalcitationids=\"CR28\" citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eHowever, these technologies face significant challenges. A major concern is the high cost of materials in MEG development, which could restrict large-scale implementation and reduce accessibility for end users. Moreover, the requirement for partial sealing complicates fabrication and limits design flexibility, and the spacing required between current collectors to sustain the moisture gradient can further increase internal resistance\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Conversion occurs only during water sorption\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e (33); if an MEG material or device is left exposed to an open environment when not in use, it ultimately becomes incapable of power generations\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Moisture-electric generators (MEGs) typically produce voltages of \u0026le;\u0026thinsp;0.6 V, which is insufficient for direct integration into wearable electronics and smart textile applications\u003csup\u003e\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThus, these limitations pose barriers to the development and application of MEG materials and devices. This research addresses these challenges by developing a MEG-based composite battery (MECB) that incorporates sustainable, cost-effective materials, increases scalability, simplifies fabrication processes, and improves energy generation efficiency to advance the practical application of MEG technologies.\u003c/p\u003e"},{"header":"Materials and Methodology","content":"\u003cp\u003e \u003cb\u003eEngineering MEG-Based Composite Battery (MECB).\u003c/b\u003e \u003c/p\u003e \u003cp\u003eTo engineer the MECB, the composite structure was strategically designed to enhance power generation. The current collector was created on the surface of the composite. This structure comprises multiple functional layers in a planar configuration that enhance moisture-driven ion transport and electrical output while ensuring flexibility.\u003c/p\u003e \u003cp\u003e \u003cb\u003eArchitecting the composite.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe design of the composite was illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ea. Lignocellulosic material such as Saccharum spontaneum (wild sugarcane or kans grass) was used for its relatively high moisture content and hydrophilic nature, which shows strong water affinity due to its polar structure.\u003csup\u003e\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e\u003c/sup\u003e This affinity allows efficient moisture uptake from the environment\u003csup\u003e\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u003c/sup\u003e, which is necessary for MEG. Wild sugarcane, categorized as a waste material due to natural dispersion of mature stalks (Supplementary Fig.\u0026nbsp;1), minimizes the composite cost. It was mixed with cigarette butt fibers (CBF), also considered waste material. Fibers were extracted from cigarette butts following a series of defined steps. (Supplementary Fig.\u0026nbsp;2) Cigarette butts were collected from bins, stores, and public spaces. They were manually cleaned of unburned tobacco and ash. The paper coating was removed with a blade, and the cellulose acetate filter was extracted and hand-shredded. Fibers were washed in hot water (70°C) for 30 minutes, then scoured and bleached with aqueous NaOH (99.9% purity) and H\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e (50% concentration) at 95°C for one hour\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. Treated fibers were immersed in 0.02% H\u003csub\u003e₂\u003c/sub\u003eSO\u003csub\u003e₄\u003c/sub\u003e (100 ml) for 30 minutes at room temperature\u003csup\u003e\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u003c/sup\u003e, then rinsed several times with cold water. The fibers were cleaned using (99% purity) acetone and subsequently dried in an oven at 60°C for 60 minutes to remove heavy metal contaminants\u003csup\u003e\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e\u003c/sup\u003e. These purified fibers were integrated into the composite structure.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eA quadrilateral composite structure was fabricated by first preparing thin sheets from sequential layers of wild sugarcane fibers. A 100°C boiled 0.95 ml saline solution (sea salt and water) was sprayed on the sheet. (Supplementary Fig.\u0026nbsp;3) Then, cigarette butt fibers were arranged in a grid pattern of horizontal and vertical lines to form squares. (Supplementary Fig.\u0026nbsp;4) Again 0.95 ml of saline solution was applied. The second thin sheet of wild sugarcane fibers was layered, followed by a final saline spray. Polyvinyl acetate resin ((C\u003csub\u003e4\u003c/sub\u003eH\u003csub\u003e6\u003c/sub\u003eO\u003csub\u003e2\u003c/sub\u003e)\u003csub\u003en\u003c/sub\u003e) was used as a binder to ensure cohesion. The composite was processed into thin sheets by felting process, thoroughly dried, and cut into quadrilateral shapes.\u003c/p\u003e \u003cp\u003e \u003cb\u003eFabrication of permanent current collectors for the MECB.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eCurrent collectors play a vital role by enabling the effective collection and distribution of generated electricity, which enhances charge/discharge performance and provides structural support\u003csup\u003e\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e\u003c/sup\u003e. The positive current collector was fabricated on one side of the composite using a Carbon Black (CB)-Manganese Dioxide (MnO₂) mixture sourced from non-functional dry cell batteries, classified as e-waste. Carbon processed into porous CB provides a large surface area that is ideal for chemical binding which enhances reactions and improves absorption functionality\u003csup\u003e\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e\u003c/sup\u003e. Moreover, MnO₂ is a low-cost, abundant, and eco-friendly material with high capacitance for energy storage\u003csup\u003e\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eThis CB - MnO₂ mixture is cost-effective and upcycling waste into higher-value products. Sea salt commonly known as sodium chloride (NaCl) was selected for its environmental stability and its ability to absorb up to 500% of its weight in moisture under high relative humidity conditions\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. Thus, NaCl absorbs moisture under high RH (Supplementary Fig.\u0026nbsp;5). Although other hygroscopic salts like lithium chloride (LiCl) and calcium chloride (CaCl\u003csub\u003e₂\u003c/sub\u003e)\u003csup\u003e39\u003c/sup\u003e were considered (Supplementary Fig.\u0026nbsp;6) but NaCl was selected for cost-effectiveness, high availability environmental safety, and optimal ionic activity. Moreover, experimental analysis further indicates that NaCl exhibits the fastest moisture uptake on the composites (Supplementary Fig.\u0026nbsp;7).\u003c/p\u003e \u003cp\u003eThe mixture of Carbon Black-MnO₂, sea salt, and water is termed the mixture-salt electrolyte solution. Due to its insolubility in saline water (Supplementary Fig.\u0026nbsp;8), minimal water is recommended for paste formation. The solution was applied to one side of the composites by brush coating. An initial conductivity of 1.37 × 10⁻⁷ S m⁻¹ was achieved at a 5.41 g m⁻² loading density, increasing to 1.0 × 10⁻⁶ S m⁻¹ at 9.46 g m⁻² after three times coating repetitions (Supplementary Fig.\u0026nbsp;9–10). Coated composites were thoroughly dried in oven at 70°C. Experimental evidence shows that the carbon-coated composite possesses enhanced moisture absorption and desorption behaviour relative to the uncoated composite, which is essential for effective moisture-driven energy conversion in MEG devices (Supplementary Fig.\u0026nbsp;11). Ultra-flexible aluminum foil collected from e-waste served as the negative collector to ensure cost efficiency and sustainability. It was collected and washed with detergent at 60°C for 30 minutes, then attached to the other side of the composite’s top surface using polyvinyl acetate. The entire structure was dried in oven at 70°C. The entire fabrication of the MECB is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eb, with a 3D schematic of the structural design presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ec. Further characterization using scanning electron microscopy (SEM) revealed the fibrous architecture, coated surface of the composite (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003ed) and porous composition, while energy-dispersive X-ray spectroscopy (EDX) showed the elemental distribution of Na and Cl (Supplementary Fig.\u0026nbsp;12).\u003c/p\u003e \u003cp\u003e \u003cb\u003eWorking Principle of the MECB.\u003c/b\u003e \u003c/p\u003e \u003cp\u003eThe battery operates through a hydrovoltaic mechanism that harnesses absorbed atmospheric moisture and facilitates ionic transport within the engineered composite (Supplementary Fig.\u0026nbsp;13). Upon exposure to RH, the composite absorbs moisture from the surrounding air. The absorbed water causes NaCl to dissociate into Na⁺ and Cl⁻ ions (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea) which follows the fundamental principles of electrolyte dissociation\u003csup\u003e\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e\u003c/sup\u003e. Ions move from regions of high concentration to low concentration. This movement occurs during moisture absorption, while ion backflow occurs during moisture desorption (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb). The transfer of ions from high to low concentration creates a potential difference that generates electrical energy (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec) between the current collectors\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e\u003c/sup\u003e (Supplementary Fig.\u0026nbsp;14).\u003c/p\u003e \u003cp\u003eWater plays dual roles as a medium for ionization and driver of ionic mobility. In hydrophilic materials, absorbed water forms ion transport pathways and enables ion movement essential for electric potential\u003csup\u003e\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u003c/sup\u003e. It also enhances surface interaction and maximizes area for effective MEG\u003csup\u003e\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e\u003c/sup\u003e. Density Functional Theory (DFT)\u003csup\u003e\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e\u003c/sup\u003e offers theoretical insight into this charge transfer mechanism\u003csup\u003e\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e\u003c/sup\u003e. Charges accumulate at the surface with pure water (0.0031e per H₂O molecule), but saline water (NaCl-embedded) shows result in a much higher charge transfer of 0.0189e, nearly six times greater\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. In this study, NaCl ions embedded in the structure enhance surface charge during moisture absorption and thereby enable electricity generation.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe CB embedded in the composite facilitates electric double layer (EDL) formation at electrode interfaces, increases charge separation, and stabilizes voltage output by adsorbing counter-ions\u003csup\u003e\u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u003c/sup\u003e. The composite surface shows three RH-dependent regimes (Supplementary Fig.\u0026nbsp;15). At low RH, it remains dry and inactive because insufficient moisture prevents bond formation with NaCl. At 65% RH, moisture absorption supports ion mobility and EDL stability, which results in peak voltage efficiency but moderate power output due to limited current generation. At high RH, abundant moisture absorbed by the composite reacts with NaCl to form Na⁺ and Cl⁻ ions, that leads to higher current flow and greater overall power generation (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ed and Supplementary Fig.\u0026nbsp;16). These regimes also appear through surface color variation (Supplementary Fig.\u0026nbsp;17). According to the Stern model\u003csup\u003e\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e\u003c/sup\u003e, the relationship between EDL surface charge density\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e and potential difference is defined. Water molecules dissociate into H⁺ and OH⁻ and increase surface charge density. NaCl provides Na⁺ ions that adsorb onto CB particles and increase charge separation\u003csup\u003e\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e\u003c/sup\u003e.\u003c/p\u003e \u003cp\u003eAnother key factor is the battery’s repeatable voltage generation cycle, regulated by the moisture absorption and desorption process\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e. Electrical signals appear only after moisture absorption which confirms ambient humidity as the energy source\u003csup\u003e\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e. The system maintains stable performance within a defined RH range and delivers consistent energy output. It enables a sustainable closed-loop green energy source\u003csup\u003e\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u003c/sup\u003e (Supplementary Fig.\u0026nbsp;18). The interaction between water molecules and hygroscopic materials induces structural deformation, commonly observed as swelling (Supplementary Fig.\u0026nbsp;19) during moisture absorption and shrinking during desorption\u003csup\u003e\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e\u003c/sup\u003e. A defining characteristic of the MECB is its hygroscopic nature; at elevated RH, the composite rapidly absorbs water and becomes hydrated, whereas at reduced RH, it releases moisture and dehydrate (Supplementary Fig.\u0026nbsp;20). This behavior was also evident in the fully coated composite (Supplementary Fig.\u0026nbsp;21). The lignocellulosic and cellulose-based materials in the MECB are inherently hydrophilic, with polar groups like hydroxyl and carbonyl that adsorb water through hydrogen bonding\u003csup\u003e\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u003c/sup\u003e (Supplementary Fig.\u0026nbsp;22). This dynamic humidity response is critical for moisture-induced charge generation in the composite.\u003c/p\u003e "},{"header":"Result and Discussion","content":"\u003cp\u003e \u003cb\u003eElectricity Generation of MECB.\u003c/b\u003e \u003c/p\u003e\u003cp\u003eAccording to our observations, during moisture absorption, ion transport and water molecule ionization within the composite facilitate charge separation and thereby induce voltage and current generation (Supplementary Fig.\u0026nbsp;23). The MECB demonstrated varying open-circuit voltages (V\u003csub\u003eoc\u003c/sub\u003e), with the highest recorded value of approximately 1.16 V. Additionally, the short-circuit current (I\u003csub\u003esc\u003c/sub\u003e) was measured in several microamperes (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea). Electrical output is observed only when two distinct current collectors are placed across the composite. No output is detected with connections in the same region which indicates the necessity of a water content gradient for electricity generation\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. The distance between current collectors significantly impacts performance (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb). Voltage and current varies, and contact quality and local moisture output. Therefore, power generation efficiency depends strongly on the minimum distance between the two current collectors. The V\u003csub\u003eoc\u003c/sub\u003e of the MECB sustained different ranges over 9 days (216 hours) under varying temperature and humidity (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec). The I\u003csub\u003esc\u003c/sub\u003e is also sustained over time across a range of current levels and varying temperature and humidity conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed). These electrical responses indicate that the MECB continues to operate under ambient temperature and humidity conditions when exposed to an open environment for extended periods. It is noteworthy that the entire MECB remained exposed to an open humid environment throughout the long-term measurement and continued to operate even after full water absorption\u003csup\u003e\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e,\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u003c/sup\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ee).\u003c/p\u003e\u003cp\u003eFundamentally, the absorbed water content controls the moisture gradient and influences overall MECB behavior. Water loss from external thermal stimuli reduces output, but prior MEG studies confirm functionality restoration via water reabsorption\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. To investigate this, we examined MECB behavior under light exposure. A random full day (24 hours) was selected for experimental analysis. The V\u003csub\u003eoc\u003c/sub\u003e dropped significantly upon illumination but recovered after the light source was turned off (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ef). This is attributed to the CB-MnO₂ mixture in the current collector, where CB functions as a photothermal material\u003csup\u003e\u003cspan citationid=\"CR53\" class=\"CitationRef\"\u003e53\u003c/span\u003e\u003c/sup\u003e. Another analysis shows that under rapid heating water desorption occurs faster than absorption during cooling and uptake remains slow at high temperature (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eg).\u003c/p\u003e\u003cp\u003eAnother key observation is the mass of the composite affects MECB’s self-recharging behavior. When exposed to high heat, the battery dried completely and the voltage dropped sharply. Upon re-exposure to the natural environment, gradual moisture reabsorption occurred. During this period, the MECB showed a self-recharge effect (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eh). These results confirm that MECB performance decreases with moisture loss and then returns to a self-recharge state as mass recovery occurs\u003csup\u003e\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e\u003c/sup\u003e. The regained moisture leads to progressive V\u003csub\u003eoc\u003c/sub\u003e recovery through natural adsorption and allows the MECB to accumulate electricity and sustainably harvest energy from environmental humidity (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ei).\u003c/p\u003e\u003cp\u003eTo further understand the dynamic behavior of the MECB, time-resolved absorption and desorption experiments were conducted under controlled environmental conditions. Based on overall performance we selected two samples (Sample A and B) for analysis. During moisture absorption (MA%) I\u003csub\u003esc\u003c/sub\u003e increased proportionally (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ea and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eb). In contrast, during moisture desorption (MD%) I\u003csub\u003esc\u003c/sub\u003e decreased accordingly (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ec and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ed). However, V\u003csub\u003eoc\u003c/sub\u003e showed a nonlinear response to both MA% (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ee and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003ef) and MD% (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eg and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eh). This formed an asymmetric bell-shaped trend that defines a critical hydration window where ion transport and interfacial polarization reach maximum efficiency. Excess moisture induced dielectric screening and caused a V\u003csub\u003eoc\u003c/sub\u003e drop. The faster rate of MA% compared with MD% in natural environments reflects rapid ionic activation from moisture influx, while the slower decline during desorption results from bound water retention and delayed ionic deactivation within the porous matrix. Time-resolved measurements show that current rises sharply during initial moisture contact and decays gradually during desorption (Supplementary Fig.\u0026nbsp;24). V\u003csub\u003eoc\u003c/sub\u003e peaks gradually and then fluctuates as the system approaches moisture equilibrium (Supplementary Fig.\u0026nbsp;25).\u003c/p\u003e\u003cp\u003e \u003cb\u003eGeometry Optimization for MECB Output.\u003c/b\u003e \u003c/p\u003e\u003cp\u003eThe preliminary observation in MECB was that a larger area exhibited an increase in output by enhancing I\u003csub\u003esc\u003c/sub\u003e\u003csup\u003e\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u003c/sup\u003e. However, further investigation showed final power output depends more on ion transport efficiency and moisture distribution rather than total surface area. To validate this, four MECB samples with different surface areas but identical length, width, and thickness were fabricated (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ea). Power Density was estimated as\u003c/p\u003e\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:P=({V}_{oc}.{I}_{sc})/4(A.d)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003cp\u003eWhere \u003cem\u003eA\u003c/em\u003e is the projected area and \u003cem\u003ed\u003c/em\u003e is thickness. Sample A showed the highest volumetric power density of approximately 16.44 µW cm⁻³ (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eb) and a corresponding gravimetric power density of approximately 2.41 g cm⁻³ based on its density. Sample B showed the highest gravimetric power density of approximately 15.74 µW g⁻¹ (Supplementary Fig.\u0026nbsp;26) and it confirmed highest power output among all tested samples (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ec) It showed a value approximately five times greater than that of the lowest-powered sample. (Supplementary Fig.\u0026nbsp;27) However, its volumetric power density was lower (≈ 5.1 µW cm⁻³). This contrast highlights the importance of balancing material efficiency per unit mass and total power output per unit volume in MECB. The optimal composite thickness increases voltage and current and produces superior power (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ed). The structure lowers internal resistance and improves ion transport, which gives higher performance. Thus, careful geometric balancing is essential for improving MEG performance.\u003c/p\u003e\u003cp\u003eA crucial factor is that MECB performance is entirely moisture-dependent. The generator operates as a fully moisture-driven energy harvesting system, where RH dynamically controls the internal water gradient. The results indicate that voltage output increases with RH, peaking at ≈ 65% and beyond 65%, V\u003csub\u003eoc\u003c/sub\u003e drops gradually (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ee). The composite contains NaCl with a deliquescent RH of 75% at 25°C, allowing it to absorb significant moisture from the environment\u003csup\u003e\u003cspan citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e\u003c/sup\u003e. NaCl enhances ion transport by dissociating into Na⁺ and Cl⁻ and supports moisture uptake through its hygroscopic nature which boosts electrochemical potential and V\u003csub\u003eoc\u003c/sub\u003e output. In contrast to previously reported MEG systems, which typically required most specific environmental conditions and exhibited only transient electrical responses\u003csup\u003e\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e,\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e\u003c/sup\u003e. The MECB demonstrated better electrical performance across a wide range of temperatures and relative humidity levels (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003ef). This is attributed to the composite materials and hygroscopic salts, which help retain moisture and ensure stable voltage despite changes in environmental temperature\u003csup\u003e\u003cspan citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u003c/sup\u003e. However, extreme temperatures cause excess moisture loss which significantly reduces charge transport and voltage (Supplementary Fig.\u0026nbsp;28). RH variations regulate the internal water gradient and thereby influence ion mobility and overall charge transport efficiency. Normal temperatures allow better moisture absorption and further enhance MECB performance (Supplementary Fig.\u0026nbsp;29).\u003c/p\u003e\u003cp\u003e \u003cb\u003eFunctional Integration and Application Prospects of the MECB.\u003c/b\u003e \u003c/p\u003e\u003cp\u003eThe MECB holds significant potential as an energy-harvesting and power-generation technology. Its production is cost-effective, as the entire system is fabricated using waste materials (Supplementary Fig.\u0026nbsp;30). This approach promotes upcycling while ensuring sustainability and efficient utilization of discarded resources. The MECB demonstrates outstanding mechanical flexibility and maintains superior voltage output under bending conditions (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea). Scaling up the MECB’s power output is achieved by series and parallel connection of multiple units, which respectively enhance V\u003csub\u003eoc\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb) and I\u003csub\u003esc\u003c/sub\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ec and Supplementary Fig.\u0026nbsp;31). The series configuration uses sequential connection of MECB units and allows scalable voltage enhancement through cumulative ionic potential. This arrangement ensures structural simplicity and continuous electrical conduction. The highest V\u003csub\u003eoc\u003c/sub\u003e recorded for a single MECB was 1.16 V at 65% RH (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ed). There are several modes of power output from the MECB. Storing the generated electricity in a capacitor is an effective way to make it accessible when required (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ee). The MECB can also be used directly for energy supply (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ef). Four MECBs were connected in series and self-charged through moisture absorption. At 30.5°C and 80% RH, the system generated 1.79 V and 323 µA, sufficient to illuminate a 3 mm red LED for over 3 hours (Supplementary Movie 1).\u003c/p\u003e\u003cp\u003eThis RH-dependent performance highlights its potential for passive humidity-responsive systems and long-duration micro-power applications. Unlike most previously reported moisture-induced generators that require capacitors\u003csup\u003e\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e\u003c/sup\u003e, the MECB directly powered the LED (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eg). After the LED was turned off, post-discharge measurements showed a residual voltage of 1.70 V with no current under the same load conditions (Supplementary Fig.\u0026nbsp;32). By weight, the MECB delivers 1.52 V at 1.48 g and provides a strong balance between voltage and mass. In contrast conventional 1.5 V batteries like Olympic, Sunlight, Murata LR44\u003csup\u003e58\u003c/sup\u003e, and Enfuel Soft Battery\u003csup\u003e\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e\u003c/sup\u003e are significantly heavier. It offers a higher voltage-to-weight ratio making it well suited for lightweight wearable applications (Supplementary Table\u0026nbsp;1).\u003c/p\u003e\u003ch3\u003eBaqui's Moist Electric Generation Model (Baqui's MEG Model)\u003c/h3\u003e\u003cp\u003eThe MEG systems integrate hydrophilic materials and hygroscopic salts. These components collectively enable moisture absorption, ion dissociation, and subsequent charge transfer which constitute the basis of MEG-based energy harvesting system. Given the fundamental role of these mechanisms, this study introduces a conceptual model, “Baqui’s Moist Electric Generation Model (Baqui’s MEG Model),” which mathematically describes the relationship between moisture absorption and electrical output.\u003c/p\u003e\u003cp\u003eBaqui’s MEG Model States that,\u003c/p\u003e\u003cp\u003e \u003cem\u003e\"In a system combining hydrophilic materials, hygroscopic salts, and moisture, an increase in moisture absorption leads to a proportional increase in ion generation, which in turn produces electrical energy when connected to conductive current collectors.\"\u003c/em\u003e \u003c/p\u003e\u003cp\u003eThis model describes the fundamental relationship between moisture absorption and power generation in MEG-based systems. Hydrophilic materials enhance atmospheric moisture absorption, while hygroscopic salts facilitate water dissociation into free ions. As moisture uptake increases, the concentration of dissociated ions rises proportionally, which enhances ion mobility and charge transport. When conductive current collectors are present, these mobile ions generate electrochemical potential and enable continuous charge flow.\u003c/p\u003e\u003ch3\u003eMathematical Model for Baqui's MEG Model\u003c/h3\u003e\u003cp\u003eTo establish a theoretical foundation for Baqui’s MEG Model, we propose a mathematical framework based on fundamental electrochemical principles. This model incorporates Fick’s Model of Diffusion\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e, the Nernst-Planck Eq.\u0026nbsp;6\u003csup\u003e1\u003c/sup\u003e, the Nernst Eq.\u0026nbsp;6\u003csup\u003e2\u003c/sup\u003e, and Ohm’s Model\u003csup\u003e\u003cspan citationid=\"CR63\" class=\"CitationRef\"\u003e63\u003c/span\u003e\u003c/sup\u003e. In a MEG system, moisture absorption by hydrophilic materials facilitates ion dissociation from hygroscopic salts and initiates ion movement. The flux of ions (\u003cem\u003eJ\u003c/em\u003e) is governed by Fick’s First Model of Diffusion\u003csup\u003e\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e\u003c/sup\u003e, expressed as:\u003c/p\u003e\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:J=-D\\frac{dc}{dx}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e1\u003c/div\u003e\u003c/div\u003e\u003cp\u003eWhere \u003cem\u003eJ\u003c/em\u003e represents the ionic flux, \u003cem\u003eD\u003c/em\u003e is the diffusion coefficient of ions, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\frac{dC}{dx}\\)\u003c/span\u003e\u003c/span\u003e denotes the concentration gradient of mobile ions across the material. The equation describes ion migration from high to low concentration regions driven by moisture-induced dissociation that leads to charge separation and electricity generation. As moisture absorption (\u003cem\u003eA\u003c/em\u003e) increases, the ion concentration (\u003cem\u003eC\u003c/em\u003e) within the system exhibits a proportional relationship, expressed as:\u003c/p\u003e\u003cdiv id=\"Equ3\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ3\" name=\"EquationSource\"\u003e\n$$\\:C={k}_{A}A$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e2\u003c/div\u003e\u003c/div\u003e\u003cp\u003eWhere \u003cem\u003ek\u003c/em\u003e\u003csub\u003e\u003cem\u003eA\u003c/em\u003e\u003c/sub\u003e is a constant dependent on material hygroscopicity and salt dissociation efficiency. This relationship highlights that greater moisture uptake increases free ion availability which enhances ionic conductivity and supports charge transport. The rate of ion generation follows:\u003c/p\u003e\u003cdiv id=\"Equ4\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ4\" name=\"EquationSource\"\u003e\n$$\\:\\frac{dc}{dt}=\\alpha\\:A$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003cp\u003eHere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\frac{dC}{dt}\\)\u003c/span\u003e\u003c/span\u003e represents the rate of change of ion concentration over time and \u003cem\u003eα\u003c/em\u003e is a material-dependent coefficient that characterizes the efficiency of ion dissociation per unit of absorbed moisture. The equation illustrates that higher moisture absorption leads to a proportional increase in ion generation. This transport behavior is governed by the Nernst-Planck equation, expressed as:\u003c/p\u003e\u003cdiv id=\"Equ5\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ5\" name=\"EquationSource\"\u003e\n$$\\:J=-D\\frac{dc}{dx}+\\mu\\:CE$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e4\u003c/div\u003e\u003c/div\u003e\u003cp\u003ewhere \u003cem\u003eD\u003c/em\u003e is the ion diffusion coefficient, denotes the concentration gradient, \u003cem\u003eµ\u003c/em\u003e is the ion mobility, \u003cem\u003eC\u003c/em\u003e is the ion concentration, and \u003cem\u003eE\u003c/em\u003e represents the applied electric field. The first term in Eq.\u0026nbsp;\u003cspan refid=\"Equ5\" class=\"InternalRef\"\u003e4\u003c/span\u003e describes ion diffusion driven by concentration gradients as per Fick’s Model. The second term captures ion migration under an electric field which enhances directed charge transport. Furthermore, the generated voltage (\u003cem\u003eV\u003c/em\u003e) is dictated by the ion concentration gradient across the system, as described by the Nernst equation:\u003c/p\u003e\u003cdiv id=\"Equ6\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ6\" name=\"EquationSource\"\u003e\n$$\\:V=\\frac{RT}{zf}\\text{l}\\text{n}\\left(\\frac{{C}_{out}}{{C}_{im}}\\right)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\u003c/div\u003e\u003cp\u003ewhere \u003cem\u003eR\u003c/em\u003e is the universal gas constant, \u003cem\u003eT\u003c/em\u003e is the absolute temperature, \u003cem\u003ez\u003c/em\u003e is the charge number of the ions, F is the Faraday constant, \u003cem\u003eC\u003c/em\u003e\u003csub\u003e\u003cem\u003eout\u003c/em\u003e\u003c/sub\u003e and \u003cem\u003eC\u003c/em\u003e\u003csub\u003e\u003cem\u003ein\u003c/em\u003e\u003c/sub\u003e are the ion concentrations at the two points (electrodes/current collectors). As moisture absorption increases, the higher ion concentration gradient strengthens the electrochemical potential and enhances the voltage output. The relationship between the \u003cem\u003eV\u003c/em\u003e and \u003cem\u003eA\u003c/em\u003e can be expressed as:\u003c/p\u003e\u003cdiv id=\"Equ7\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ7\" name=\"EquationSource\"\u003e\n$$\\:V\\propto\\:\\text{l}\\text{n}\\left(A\\right)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e6\u003c/div\u003e\u003c/div\u003e\u003cp\u003eHere \u003cem\u003ek\u003c/em\u003e\u003csub\u003e\u003cem\u003eV\u003c/em\u003e\u003c/sub\u003e is a constant that includes material-specific factors. The equation indicates that \u003cem\u003eV\u003c/em\u003e increases logarithmically with \u003cem\u003eA\u003c/em\u003e as higher ion concentration enhances electrochemical potential. Besides, \u003cem\u003eI\u003c/em\u003e generated is related to \u003cem\u003eV\u003c/em\u003e and \u003cem\u003eR\u003c/em\u003e (electrical resistance) of the material, based on Ohm's law which expressed as:\u003c/p\u003e\u003cdiv id=\"Equ8\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ8\" name=\"EquationSource\"\u003e\n$$\\:I=\\frac{V}{R}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e7\u003c/div\u003e\u003c/div\u003e\u003cp\u003eAccording to this relationship, for a given material, an increase in \u003cem\u003eV\u003c/em\u003e will lead to an increase in the \u003cem\u003eI\u003c/em\u003e generated, provided that the \u003cem\u003eR\u003c/em\u003e remains constant. The system resistance \u003cem\u003eR\u003c/em\u003e depends on ionic conductivity, geometry and ion transport efficiency. Increased \u003cem\u003eA\u003c/em\u003e enhances conductivity which lowers resistance and boosts current output. The \u003cem\u003eR\u003c/em\u003e is given by:\u003c/p\u003e\u003cdiv id=\"Equ9\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ9\" name=\"EquationSource\"\u003e\n$$\\:R=\\frac{L}{\\sigma\\:A}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e8\u003c/div\u003e\u003c/div\u003e\u003cp\u003ewhere \u003cem\u003eL\u003c/em\u003e represents the length of the conductive path through the material, \u003cem\u003e𝜎\u003c/em\u003e is the ionic conductivity, and \u003cem\u003eA\u003c/em\u003e is the cross-sectional area through which the ions are transported. This relationship shows \u003cem\u003eR\u003c/em\u003e decreases with higher ionic conductivity or cross-sectional area and increases with material length. As \u003cem\u003eA\u003c/em\u003e increases ionic conductivity improves which reduces \u003cem\u003eR\u003c/em\u003e and increases \u003cem\u003eI\u003c/em\u003e as described by Ohm's Model (Eq.\u0026nbsp;\u003cspan refid=\"Equ8\" class=\"InternalRef\"\u003e7\u003c/span\u003e). Again, as \u003cem\u003eA\u003c/em\u003e increases, the \u003cem\u003eσ\u003c/em\u003e is directly proportional to \u003cem\u003eA\u003c/em\u003e, which can be expressed as:\u003c/p\u003e\u003cdiv id=\"Equ10\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ10\" name=\"EquationSource\"\u003e\n$$\\:\\sigma\\:\\propto\\:A$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e9\u003c/div\u003e\u003c/div\u003e\u003cp\u003eThus, the generated current \u003cem\u003eI\u003c/em\u003e can be written as:\u003c/p\u003e\u003cdiv id=\"Equ11\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ11\" name=\"EquationSource\"\u003e\n$$\\:I=\\frac{kVln\\left(A\\right).k\\sigma\\:A}{L}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e10\u003c/div\u003e\u003c/div\u003e\u003cp\u003ewhere, \u003cem\u003ek\u003c/em\u003e is a proportionality constant. Here, \u003cem\u003ek\u003c/em\u003e\u003csub\u003e\u003cem\u003eσ\u003c/em\u003e\u003c/sub\u003e reflects material properties including ion dissociation efficiency. The power output (\u003cem\u003eP\u003c/em\u003e) of the system can be expressed as,\u003c/p\u003e\u003cdiv id=\"Equ12\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ12\" name=\"EquationSource\"\u003e\n$$\\:P=VI$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e11\u003c/div\u003e\u003c/div\u003e\u003cp\u003eSubstituting the \u003cem\u003eV\u003c/em\u003e and \u003cem\u003eI\u003c/em\u003e from Equations (\u003cspan refid=\"Equ7\" class=\"InternalRef\"\u003e6\u003c/span\u003e) and (\u003cspan refid=\"Equ11\" class=\"InternalRef\"\u003e10\u003c/span\u003e), respectively, the power output becomes:\u003c/p\u003e\u003cdiv id=\"Equ13\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ13\" name=\"EquationSource\"\u003e\n$$\\:P=\\left(kVln\\left(A\\right)\\right)\\frac{kVk\\sigma\\:Aln\\left(A\\right)}{L}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e12\u003c/div\u003e\u003c/div\u003e\u003cp\u003eSimplifying, we get:\u003c/p\u003e\u003cdiv id=\"Equ14\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ14\" name=\"EquationSource\"\u003e\n$$\\:P=\\frac{{k}^{2}VK\\sigma\\:A{ln}^{2}\\left(A\\right)}{L}$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e13\u003c/div\u003e\u003c/div\u003e\u003cp\u003eFinally, the derived model shows that the \u003cem\u003eP\u003c/em\u003e is directly proportional to \u003cem\u003eA\u003c/em\u003e with a logarithmic dependence, expressed as:\u003c/p\u003e\u003cdiv id=\"Equ15\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ15\" name=\"EquationSource\"\u003e\n$$\\:P\\propto\\:A{ln}^{2}\\left(A\\right)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e14\u003c/div\u003e\u003c/div\u003e\u003cp\u003eThis equation supports Baqui’s MEG Model by showing that increased moisture absorption increases ion concentration which enhances ionic conductivity and improves power output highlighting the key role of moisture in system performance. This behavior aligns with the fundamental principles of ion transport and electrochemical potential and also shows the importance of optimizing moisture absorption to maximize power output.\u003c/p\u003e\u003ch3\u003eValidation and Applicability of Baqui’s MEG Model\u003c/h3\u003e\u003cp\u003eTo validate the proposed model that describes the relationship between moisture absorption and power generation, controlled experiments were conducted using MECB. The mathematical model states that the generated power output, P depends on the moisture absorption capacity, A by following the relationship:\u003c/p\u003e\u003cdiv id=\"Equ16\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ16\" name=\"EquationSource\"\u003e\n$$\\:P=KA{ln}^{2}\\left(A\\right)$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e15\u003c/div\u003e\u003c/div\u003e\u003cp\u003eThis study experimentally evaluated this equation and found an \u003cem\u003eR²\u003c/em\u003e value of 0.95. (Supplementary Table\u0026nbsp;2). This high coefficient confirms that the model captures power generation behavior with excellent accuracy. The experimental data and the theoretical curve align well across the entire moisture absorption range (Supplementary Fig.\u0026nbsp;33). The \u003cem\u003eK\u003c/em\u003e value of 0.155 is a material-specific constant reflecting ion mobility, porosity, interfacial conductivity and internal moisture-driven potential gradients. The key consideration is that Baqui’s MEG model establishes a broadly applicable theoretical framework for understanding moisture-electric generation. Beyond our system, we qualitatively aligned the model with trends from previous MEG devices. While the equation links moisture absorption to power output, earlier studies often correlate power output with relative humidity (RH%) or RH and voltage/current. (Supplementary Fig.\u0026nbsp;34). However, as RH rises, moisture absorption by materials increases proportionally\u003csup\u003e\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e\u003c/sup\u003e due to the greater uptake by hydrophilic and hygroscopic materials, particularly at high RH. Our experimental data (Supplementary Table\u0026nbsp;3) further confirm RH as a reliable indicator of moisture absorption across diverse MEG platforms. However, MEG systems vary in material properties, fabrication methods, structure and measurement conditions. Despite these differences, our equation aligns with trends in previous MEG studies showing that power output rises with absorbed moisture of its natural logarithm. This confirms that moisture enhances electricity generation through a nonlinear effect. These results suggest Baqui’s MEG Model provides a robust and general framework for understanding moisture-induced electricity generation across diverse materials and device designs.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, we have successfully developed an innovative MECB by engineering a multifunctional composite structure from waste-derived materials. The MECB exhibits robust and repeatable energy output driven by moisture-induced ion transport under ambient humidity. The integration of wild sugarcane and recycled cigarette butt fibers with a salt-based electrolyte derived from e-waste enables the fabrication of a flexible and scalable green energy-harvesting device. A functional imbalance created by different current collectors sustains voltage output even after full moisture saturation. The system remained operational under extended open-environment conditions and exhibited a self-regenerating behavior through dynamic desorption and absorption cycles. A single MECB achieved highest 1.16 V open-circuit voltage and 16.44 \u0026micro;W cm⁻\u0026sup3; power density. The connection of multiple MECB units in series or parallel enhances the energy output and offers a scalable strategy for long-duration and low-power applications. We compared the performance with previous MEGs and found that MECB demonstrates comparatively improved efficiency. (Supplementary Table\u0026nbsp;4) We also propose \u0026lsquo;Baqui\u0026rsquo;s Moist Electric Generation Model\u0026rsquo; as a fundamental framework that links moisture absorption, ion dissociation, and electricity generation to guide future MEG system design. These findings highlight both practical viability and deeper insights into moisture\u0026ndash;material interactions for next-generation energy system.\u003c/p\u003e "},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAll data supporting the findings of this study are available within the Source Data file and the Supplementary Information associated with this article.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThese authors contributed equally: Aman Ul Azam Khan and Nazmunnahar Nazmunahar.\u003c/p\u003e\n\u003cp\u003eA.U.A.K. and N.N. designed the experiments and prepared the original draft. M.H. performed the theoretical calculations and conducted the data analysis. All authors discussed the results and contributed to manuscript revision. A.B. supervised the overall project.\u003c/p\u003e\n\u003cp\u003eCorresponding authors: Nazmunnahar Nazmunnahar\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding Declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received no external funding.\u003c/p\u003e\n"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eGuan, P. et al. Recent development of moisture-enabled‐electric nanogenerators. \u003cem\u003eSmall\u003c/em\u003e \u003cb\u003e18\u003c/b\u003e, 2204603 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, Y. et al. An asymmetric hygroscopic structure for moisture-driven hygro‐ionic electricity generation and storage. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cb\u003e34\u003c/b\u003e, 2201228 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXie, J. W., Chen, L., Yang, X., Wu, P. \u0026amp; Huang, F. (2019). Yuelong. (IntechOpen.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXue, G. et al. Water-evaporation-induced electricity with nanostructured carbon materials. \u003cem\u003eNat. Nanotechnol.\u003c/em\u003e \u003cb\u003e12\u003c/b\u003e, 317\u0026ndash;321 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSoares, P. \u003cem\u003eElectrical energy generation through water evaporation using porous membranes\u003c/em\u003e (Universidade do Porto (Portugal), 2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYin, J. et al. Generating electricity by moving a droplet of ionic liquid along graphene. \u003cem\u003eNat. Nanotechnol.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e, 378\u0026ndash;383 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYin, J. et al. Waving potential in graphene. \u003cem\u003eNat. Commun.\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e, 3582 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang, Y. et al. All-region-applicable, continuous power supply of graphene oxide composite. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e12\u003c/b\u003e, 1848\u0026ndash;1856 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFu, C. et al. A Long Life Moisture-Enabled Electric Generator Based on Ionic Diode Rectification and Electrode Chemistry Regulation. \u003cem\u003eAdv. Sci.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e, 2305530 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHuang, Y. et al. Interface-mediated hygroelectric generator with an output voltage approaching 1.5 volts. \u003cem\u003eNat. Commun.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e, 4166 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang, Y., Nandakumar, D. K. \u0026amp; Tan, S. C. Digestion of ambient humidity for energy generation. \u003cem\u003eJoule\u003c/em\u003e \u003cb\u003e4\u003c/b\u003e, 2532\u0026ndash;2536 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNandakumar, D. K., Vaghasiya, J. V., Yang, L., Zhang, Y. \u0026amp; Tan, S. C. A solar cell that breathes in moisture for energy generation. \u003cem\u003eNano Energy\u003c/em\u003e. \u003cb\u003e68\u003c/b\u003e, 104263 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang, L. et al. Energy harvesting from atmospheric humidity by a hydrogel-integrated ferroelectric-semiconductor system. \u003cem\u003eJoule\u003c/em\u003e \u003cb\u003e4\u003c/b\u003e, 176\u0026ndash;188 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, X. et al. Metalized polyamide heterostructure as a moisture-responsive actuator for multimodal adaptive personal heat management. \u003cem\u003eSci. Adv.\u003c/em\u003e \u003cb\u003e7\u003c/b\u003e, eabj7906 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEjeian, M. \u0026amp; Wang, R. Adsorption-based atmospheric water harvesting. \u003cem\u003eJoule\u003c/em\u003e \u003cb\u003e5\u003c/b\u003e, 1678\u0026ndash;1703 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLord, J. et al. Global potential for harvesting drinking water from air using solar energy. \u003cem\u003eNature\u003c/em\u003e \u003cb\u003e598\u003c/b\u003e, 611\u0026ndash;617 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYang, J. et al. A moisture-hungry copper complex harvesting air moisture for potable water and autonomous urban agriculture. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cb\u003e32\u003c/b\u003e, 2002936 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHanikel, N. et al. Evolution of water structures in metal-organic frameworks for improved atmospheric water harvesting. \u003cem\u003eScience\u003c/em\u003e \u003cb\u003e374\u003c/b\u003e, 454\u0026ndash;459 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003evan der Heyden, F. H., Stein, D. \u0026amp; Dekker, C. Streaming currents in a single nanofluidic channel. \u003cem\u003ePhys. Rev. Lett.\u003c/em\u003e \u003cb\u003e95\u003c/b\u003e, 116104 (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eVan der Heyden, F. H., Stein, D., Besteman, K., Lemay, S. G. \u0026amp; Dekker, C. Charge inversion at high ionic strength studied by streaming currents. \u003cem\u003ePhys. Rev. Lett.\u003c/em\u003e \u003cb\u003e96\u003c/b\u003e, 224502 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJoly, L., Ybert, C., Trizac, E. \u0026amp; Bocquet, L. Hydrodynamics within the electric double layer on slipping surfaces. \u003cem\u003ePhys. Rev. Lett.\u003c/em\u003e \u003cb\u003e93\u003c/b\u003e, 257805 (2004).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, F., Cheng, H., Zhang, Z., Jiang, L. \u0026amp; Qu, L. Direct power generation from a graphene oxide film under moisture. \u003cem\u003eAdv. Mater. (Deerfield Beach Fla)\u003c/em\u003e. \u003cb\u003e27\u003c/b\u003e, 4351\u0026ndash;4357 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhao, F., Liang, Y., Cheng, H., Jiang, L. \u0026amp; Qu, L. Highly efficient moisture-enabled electricity generation from graphene oxide frameworks. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e, 912\u0026ndash;916 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShen, D. et al. Self-powered wearable electronics based on moisture enabled electricity generation. \u003cem\u003eAdv. Mater.\u003c/em\u003e \u003cb\u003e30\u003c/b\u003e, 1705925 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMandal, S. et al. Protein-based flexible moisture-induced energy-harvesting devices as self-biased electronic sensors. \u003cem\u003eACS Appl. Electron. Mater.\u003c/em\u003e \u003cb\u003e2\u003c/b\u003e, 780\u0026ndash;789 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKwon, S. H. et al. An effective energy harvesting method from a natural water motion active transducer. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e7\u003c/b\u003e, 3279\u0026ndash;3283 (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKalia, S., Kaith, B. \u0026amp; Kaur, I. Pretreatments of natural fibers and their application as reinforcing material in polymer composites\u0026mdash;a review. \u003cem\u003ePolym. Eng. Sci.\u003c/em\u003e \u003cb\u003e49\u003c/b\u003e, 1253\u0026ndash;1272 (2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSpitalsky, Z., Tasis, D., Papagelis, K. \u0026amp; Galiotis, C. Carbon nanotube\u0026ndash;polymer composites: chemistry, processing, mechanical and electrical properties. \u003cem\u003eProg. Polym. Sci.\u003c/em\u003e \u003cb\u003e35\u003c/b\u003e, 357\u0026ndash;401 (2010).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG\u0026uuml;nther, A. \u0026amp; Jensen, K. F. Multiphase microfluidics: from flow characteristics to chemical and materials synthesis. \u003cem\u003eLab. Chip\u003c/em\u003e. \u003cb\u003e6\u003c/b\u003e, 1487\u0026ndash;1503 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu, T. et al. An efficient polymer moist-electric generator. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e12\u003c/b\u003e, 972\u0026ndash;978 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhan, A. U. A. et al. Development of the smart jacket featured with medical, sports, and defense attributes using conductive thread and thermoelectric fabric. \u003cem\u003eEngineering Proceedings\u003c/em\u003e 30, 18 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRahman, M., Das, A., Tabassum, S., Das, S. \u0026amp; Uddin, M. Physical and chemical characterization of Saccharum spontaneum flower fibre: potential applications in thermal insulation and microbial fuel cells. \u003cem\u003earXiv preprint arXiv:2501.05324\u003c/em\u003e (2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Maharma, A. Y. \u0026amp; Al-Huniti, N. Critical review of the parameters affecting the effectiveness of moisture absorption treatments used for natural composites. \u003cem\u003eJ. Compos. Sci.\u003c/em\u003e \u003cb\u003e3\u003c/b\u003e, 27 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAfroz, F., Mahmud, R. U. \u0026amp; Islam, R. Green approach to recover the cellulose acetate fiber from used cigarette butts, and characterize the filter fiber. \u003cem\u003eAATCC J. Res.\u003c/em\u003e \u003cb\u003e10\u003c/b\u003e, 311\u0026ndash;320 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBenavente, M. J., Caballero, M. J. A., Silvero, G., L\u0026oacute;pez-Coca, I. \u0026amp; Escobar, V. G. in \u003cem\u003eProceedings.\u003c/em\u003e (MDPI).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYamada, M., Watanabe, T., Gunji, T., Wu, J. \u0026amp; Matsumoto, F. Review of the design of current collectors for improving the battery performance in lithium-ion and post-lithium-ion batteries. \u003cem\u003eElectrochem\u003c/em\u003e \u003cb\u003e1\u003c/b\u003e, 124\u0026ndash;159 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTian, W. et al. Porous carbons: structure-oriented design and versatile applications. \u003cem\u003eAdv. Funct. Mater.\u003c/em\u003e \u003cb\u003e30\u003c/b\u003e, 1909265 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRupnar, D. V. et al. Recent trends and advances in MnO2-based energy storage technologies. \u003cem\u003eInorg. Chem. Commun.\u003c/em\u003e \u003cb\u003e173\u003c/b\u003e, 113784 (2025).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShan, H. et al. Hygroscopic salt-embedded composite materials for sorption-based atmospheric water harvesting. \u003cem\u003eNat. Reviews Mater.\u003c/em\u003e \u003cb\u003e9\u003c/b\u003e, 699\u0026ndash;721 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCrundwell, F. K. The impact of surface charge on the ionic dissociation of common salt (NaCl). \u003cem\u003eChem. Eng. Sci.\u003c/em\u003e \u003cb\u003e205\u003c/b\u003e, 174\u0026ndash;180 (2019).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOkada, T. et al. Ion and water transport characteristics of Nafion membranes as electrolytes. \u003cem\u003eElectrochim. Acta\u003c/em\u003e. \u003cb\u003e43\u003c/b\u003e, 3741\u0026ndash;3747 (1998).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng, J. C. et al. High output power moist-electric generator based on synergistic nanoarchitectonics for effective ion regulation. \u003cem\u003eNano Energy\u003c/em\u003e. \u003cb\u003e119\u003c/b\u003e, 109103 (2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeng, D. et al. Catalytic mechanism of Na on coal pyrolysis-derived carbon black formation: Experiment and DFT simulation. \u003cem\u003eFuel Process. Technol.\u003c/em\u003e \u003cb\u003e224\u003c/b\u003e, 107011 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBahari, Y., Mortazavi, B., Rajabpour, A., Zhuang, X. \u0026amp; Rabczuk, T. Application of two-dimensional materials as anodes for rechargeable metal-ion batteries: A comprehensive perspective from density functional theory simulations. \u003cem\u003eEnergy Storage Mater.\u003c/em\u003e \u003cb\u003e35\u003c/b\u003e, 203\u0026ndash;282 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFrackowiak, E., Abbas, Q. \u0026amp; B\u0026eacute;guin, F. Carbon/carbon supercapacitors. \u003cem\u003eJ. Energy Chem.\u003c/em\u003e \u003cb\u003e22\u003c/b\u003e, 226\u0026ndash;240 (2013).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrown, M. A., Goel, A. \u0026amp; Abbas, Z. Effect of electrolyte concentration on the stern layer thickness at a charged interface. \u003cem\u003eAngew. Chem.\u003c/em\u003e \u003cb\u003e128\u003c/b\u003e, 3854\u0026ndash;3858 (2016).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRasines, G. et al. On the use of carbon black loaded nitrogen-doped carbon aerogel for the electrosorption of sodium chloride from saline water. \u003cem\u003eElectrochim. Acta\u003c/em\u003e. \u003cb\u003e170\u003c/b\u003e, 154\u0026ndash;163 (2015).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWang, H. et al. Moisture adsorption-desorption full cycle power generation. \u003cem\u003eNat. Commun.\u003c/em\u003e \u003cb\u003e13\u003c/b\u003e, 2524 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun, Z. et al. Emerging design principles, materials, and applications for moisture-enabled electric generation. \u003cem\u003eEScience\u003c/em\u003e \u003cb\u003e2\u003c/b\u003e, 32\u0026ndash;46 (2022).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, Y. \u0026amp; Tanaka, T. Kinetics of swelling and shrinking of gels. \u003cem\u003eJ. Chem. Phys.\u003c/em\u003e \u003cb\u003e92\u003c/b\u003e, 1365\u0026ndash;1371 (1990).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEtale, A., Onyianta, A. J., Turner, S. R. \u0026amp; Eichhorn, S. J. Cellulose: a review of water interactions, applications in composites, and water treatment. \u003cem\u003eChem. Rev.\u003c/em\u003e \u003cb\u003e123\u003c/b\u003e, 2016\u0026ndash;2048 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu, X. et al. Power generation from ambient humidity using protein nanowires. \u003cem\u003eNature\u003c/em\u003e \u003cb\u003e578\u003c/b\u003e, 550\u0026ndash;554 (2020).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHan, D., Meng, Z., Wu, D., Zhang, C. \u0026amp; Zhu, H. Thermal properties of carbon black aqueous nanofluids for solar absorption. \u003cem\u003eNanoscale Res. Lett.\u003c/em\u003e \u003cb\u003e6\u003c/b\u003e, 457 (2011).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eYan, H., Liu, Z. \u0026amp; Qi, R. Development and mechanism investigation of TiO2/Co hydrogel microgenerator utilizing humidity gradient. \u003cem\u003eEnergy. Conv. Manag.\u003c/em\u003e \u003cb\u003e291\u003c/b\u003e, 117256 (2023).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBiskos, G., Malinowski, A., Russell, L., Buseck, P. \u0026amp; Martin, S. Nanosize effect on the deliquescence and the efflorescence of sodium chloride particles. \u003cem\u003eAerosol Sci. Technol.\u003c/em\u003e \u003cb\u003e40\u003c/b\u003e, 97\u0026ndash;106 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCheng, H. et al. Spontaneous power source in ambient air of a well-directionally reduced graphene oxide bulk. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e11\u003c/b\u003e, 2839\u0026ndash;2845 (2018).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eXu, J. et al. Ultrahigh solar-driven atmospheric water production enabled by scalable rapid-cycling water harvester with vertically aligned nanocomposite sorbent. \u003cem\u003eEnergy Environ. Sci.\u003c/em\u003e \u003cb\u003e14\u003c/b\u003e, 5979\u0026ndash;5994 (2021).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBrinkley, S. \u003cem\u003eTop Picks for LR44 Battery Equivalents\u003c/em\u003e, \u0026lt; (2023). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.ovaga.com/blog/fast-charging-technology/top-picks-for-lr44-battery-equivalents#simple-list-item-0\u003c/span\u003e\u003cspan address=\"https://www.ovaga.com/blog/fast-charging-technology/top-picks-for-lr44-battery-equivalents#simple-list-item-0\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eOy, E. \u003cem\u003eSoftBattery\u0026reg;: Printed Thin and Flexible Battery Solutions\u003c/em\u003e, \u0026lt;\u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://www.enfucell.com/softbattery\u003c/span\u003e\u003cspan address=\"https://www.enfucell.com/softbattery\" targettype=\"URL\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePaul, A., Laurila, T., Vuorinen, V. \u0026amp; Divinski, S. V. in \u003cem\u003eThermodynamics, diffusion and the kirkendall effect in solids\u003c/em\u003e 115\u0026ndash;139Springer, (2014).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMaex, R. On the nernst\u0026ndash;planck equation. \u003cem\u003eJ. Integr. Neurosci.\u003c/em\u003e \u003cb\u003e16\u003c/b\u003e, 73\u0026ndash;91 (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFeiner, A. S. \u0026amp; McEvoy, A. The nernst equation. \u003cem\u003eJ. Chem. Educ.\u003c/em\u003e \u003cb\u003e71\u003c/b\u003e, 493 (1994).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTenny, K. M. \u0026amp; Keenaghan, M. Ohms Law. (2017).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLi, Y. \u0026amp; Ren, S. 2-Basic properties of building decorative materials. \u003cem\u003eBuilding Decor. Materials\u003c/em\u003e, 10\u0026ndash;24 (2011).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8570579/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8570579/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eAtmospheric moisture is an abundant, renewable resource with potential for sustainable energy harvesting. While moisture\u0026ndash;material interactions can generate electricity under ambient conditions, most current systems remain expensive, specific environment dependent, and produce voltages too low for direct use in wearable electronics. To address these limitations, we developed a moisture-electric composite battery (MECB) from waste biomass and recycled materials that converts ambient humidity into continuous electrical output. The MECB integrates wild sugarcane fibers and recycled cigarette-butt cellulose with an upcycled carbon-paste layer, which enhances moisture uptake, ion dissociation, and directional ion migration across asymmetric current collectors. A single unit delivers up to 1.16 V and 16.44 \u0026micro;W cm⁻\u0026sup3;, operates continuously in open environments, and self-restores voltage after drying via natural moisture reabsorption. A conceptual model establishes the moisture\u0026ndash;electricity relationship, linking absorption to ion generation and power output. Scalable series/parallel configurations boost voltage and current, directly powering small electronics without external capacitors. This low-cost approach highlights moisture-activated textiles as sustainable, long-duration power sources for self-sufficient systems.\u003c/p\u003e","manuscriptTitle":"Moisture-driven Composite Battery from Waste Materials for Sustainable Energy Harvesting","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-01-20 11:19:18","doi":"10.21203/rs.3.rs-8570579/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-01-30T16:09:33+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-29T07:43:02+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"124042369922171805049727825412353007391","date":"2026-01-23T14:38:19+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-01-22T19:57:15+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"106333639927272724377830711896700390345","date":"2026-01-22T19:34:23+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-01-16T14:15:18+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-01-16T13:14:21+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-01-12T13:03:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-01-12T13:03:05+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-01-10T21:36:06+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"de3ca51e-e74d-4aac-9964-105c084b72ad","owner":[],"postedDate":"January 20th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"in-revision","subjectAreas":[{"id":61327400,"name":"Physical sciences/Energy science and technology"},{"id":61327401,"name":"Physical sciences/Engineering"},{"id":61327402,"name":"Earth and environmental sciences/Environmental sciences"},{"id":61327403,"name":"Physical sciences/Materials science"}],"tags":[],"updatedAt":"2026-04-21T11:40:25+00:00","versionOfRecord":[],"versionCreatedAt":"2026-01-20 11:19:18","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8570579","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8570579","identity":"rs-8570579","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}