Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors

Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors | 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 Research Article Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors Zhengyu Ding, Maoyu You, Binjie Xin, Md All Amin Newton This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7440091/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 15 You are reading this latest preprint version Abstract Flexible supercapacitors require electrode materials that integrate high specific capacitance, mechanical robustness, and efficient ionic transport. Herein, a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid membrane was synthesized via chemical oxidative polymerization and vacuum-assisted filtration. By optimizing the mass ratio of MXene to short carbon nanofiber@polyaniline (SCNF@PANI), a three-dimensional hierarchical architecture was achieved, where MXene nanosheets interlocked with PANI-coated CNFs to form covalent interface bonds. This design leverages the metallic conductivity of MXenes for rapid electron transport, CNFs' mechanical rigidity of CNFs to maintain structural integrity, and PANI's pseudo-capacitance of PANI for enhanced energy storage. The hybrid membrane exhibited exceptional electrochemical performance, achieving a specific capacitance of 601.8 F g − 1 at 5 mV s − 1 , surpassing most reported MXene-based materials. Notably, the composite retained 81.5% of its capacitance after 10,000 cycles, demonstrating remarkable cycling stability. The synergistic integration of hydrophilic MXenes, porous CNFs, and polar PANI functionalities ensures efficient electrolyte infiltration and ion diffusion. Simultaneously, the covalent interface bonds enhance the charge transfer efficiency and structural integrity. This work establishes a scalable strategy for high-performance supercapacitor electrodes, advancing the integration of MXenes with carbon nanomaterials and conductive polymers. These design principles provide new insights into interfacial engineering for multifunctional energy storage applications, particularly in flexible and high-temperature devices. Supercapacitor MXene Carbon Nanofibers Polyaniline Synergy Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1. Introduction In recent decades, owing to energy shortages and the development of modern energy storage technologies, energy storage systems[ 1 ] have garnered significant attention in both academic and industrial circles as an essential intermediate step for efficient energy utilization. Supercapacitors, a key energy storage technology[ 2 ], have gained attention owing to their high power density, fast charging/discharging ability, and long cycle life[ 3 ], filling the gap between traditional capacitors and batteries. Energy is stored in these devices mainly through two mechanisms: EDLC at the electrode-electrolyte interface[ 4 ] and pseudo-capacitance from rapid, reversible redox reactions[ 5 ]. However, their relatively low energy density compared to batteries and electrode-material-design challenges (e.g., restricted ion transport capacity[ 6 ], low specific capacitance[ 7 ], and inadequate mechanical strength[ 8 ]) hinder their widespread use. Therefore, there is an urgent need for advanced electrode materials with hierarchical nanostructures and tailored properties. Electrospinning is regarded as a powerful tool for fabricating nanostructured supercapacitor electrodes owing to its versatility and scalability[ 9 ]. Continuous nanofibers with a high specific surface area[ 10 ], tunable porosity[ 11 ], and customizable composition, which are all critical for improving electrochemical performance, can be produced using this method. Additionally, electrospinning can integrate diverse materials, such as carbon-based materials, metal oxides, conductive polymers, and hybrid composites[ 12 ], into hierarchical structures. Traditional carbon-based materials (e.g., carbon nanotubes[ 13 ] and graphene[ 14 ]) and conductive polymers (e.g., polyaniline[ 15 ] and polypyrrole[ 16 ]) have been widely explored. However, their practical application is limited by insufficient pseudo-capacitance or poor cycling stability. Recently, MXene materials (e.g., Ti₃C₂Tx), a family of two-dimensional transition metal carbides[ 17 ], have garnered attention for their metallic conductivity[ 18 ](up to 10⁴–10⁵ S cm − 1 ), high surface area[ 19 ](200–300 m² g − 1 ), and redox-active surface terminations[ 20 ](–O,–OH). Despite these advantages, MXene-based electrodes often suffer from the restacking of nanosheets[ 21 ], which reduces ion accessibility and compromises mechanical flexibility. Carbon nanofibers (CNFs)[ 22 , 23 ] have been proposed as promising structural reinforcements owing to their one-dimensional porous architecture and exceptional tensile strength (> 1.5 GPa)[ 24 ]. However, CNFs alone lack sufficient pseudo-capacitance for high-energy storage applications[ 25 ]. Conductive polymers, such as polyaniline (PANI)[ 26 ], provide pseudo-capacitance through reversible redox reactions (300–500 F g − 1 ) but suffer from low electrical conductivity (10 − 3 –10 0 S cm − 1 ) and poor long-term stability[ 27 ]. Integrating MXene, CNFs, and PANI into a ternary composite presents an opportunity to address these limitations through hierarchical synergy. While binary systems (e.g., MXene/CNF[ 28 ] or MXene/PANI[ 29 , 30 ]) have been reported, ternary systems[ 31 , 32 ] with covalent interfacial bonds (e.g., C-Ti and Ti-O) remain underexplored. These bonds are critical for enhancing the charge transfer efficiency and structural integrity. In this study, a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid membrane was synthesized via chemical oxidative polymerization[ 33 ] and vacuum-assisted filtration[ 34 ]. By optimizing the mass ratio of MXene to short carbon nanofiber@polyaniline (SCNF@PANI), a three-dimensional hierarchical architecture was achieved, in which MXene nanosheets interlocked with PANI-coated CNFs to form covalent interface bonds. This design leverages (1) the metallic conductivity of MXenes for rapid electron transport, (2) CNFs' mechanical rigidity of CNFs to maintain structural integrity, and (3) PANI's pseudo-capacitance of PANI for enhanced energy storage. The resulting composite exhibited a record-specific capacitance of 601.8 F g − 1 at 5 mV s − 1 , surpassing most reported MXene-based materials, while retaining 81.5% of its capacitance after 10,000 cycles. This work establishes a scalable strategy for overcoming the critical limitations of individual components through rational ternary design, providing new insights into interfacial engineering[ 35 ] for the fabrication of high-performance flexible supercapacitors. 2. Experimental 2.1 Materials. Polyacrylonitrile (PAN, with a molecular weight Mw = 150,000g mol − 1 ) was selected as the carbon nanofiber fabrication precursor and procured from Aladdin Reagent Company. N, N-Dimethylformamide (DMF, purity ≥ 99.8%) was used as the solvent for the spinning solution and was obtained from the China National Pharmaceutical Group Corporation. Ti ₃AlC₂ powder with a particle size of 400 mesh was obtained from 11 Technology Co, Ltd.. The etching solution was prepared using hydrochloric acid and lithium fluoride. Hydrochloric acid (HCl, with a mass fraction of 36–38%) was acquired from the China National Chemicals Corporation, and lithium fluoride (LiF) was supplied by the Aladdin Reagent Company. Ammonium persulfate (APS) was used as an oxidizing agent to initiate the chemical oxidative polymerization of aniline (AN). APS and AN were obtained from the China National Pharmaceutical Group Corporation. All chemical reagents and materials used in the experiments were of analytical grade and were employed without further purification. 2.2 Preparation of Short Carbon Nanofibers. A PAN electrospinning solution with a weight percentage of 17% was prepared for electrospinning. Electrospinning was performed at a voltage of 15 kV, with a feed rate of 0.3 mm min − 1 . The receiving distance was maintained at 20 cm, and the aluminum foil was fixed on a rotating drum at a speed of 100 rpm. The resulting PAN nanofiber membrane was collected and subjected to pre-oxidation treatment. For this treatment, the fiber membrane samples were vertically suspended in a muffle furnace, with tin foil used as a counterweight to ensure the flatness of the sample. The temperature was increased at a rate of 1°C min − 1 to 250°C, followed by a constant temperature hold for 120 min. Subsequently, the samples were naturally cooled to room temperature to obtain a pre-oxidized fiber membrane. Finally, the pre-oxidized nanofiber membrane was cut into small pieces and ground in a ball mill to produce short-CNFs. 2.3 Preparation of MXene Nanosheets. A single-layer Ti 3 C 2 Tx MXene was synthesized by etching the MAX phase Ti 3 AlC 2 using LiF and HCl as etching agents. The experimental procedure was as follows: First, 1 g of LiF was mixed with 20 mL of 6 M HCl in a beaker, and the etching solution was prepared by stirring the mixture vigorously for 30 min. To avoid an intense exothermic reaction, 1 g of Ti 3 AlC 2 was added to the etching solution in portions over 8 min. The resulting mixture was then placed in a 35°C oil bath and stirred continuously for 48 h. Subsequently, the acidic suspension was washed with deionized (DI) water and centrifuged at 3500 rpm for 5–8 cycles until the solution attained a neutral pH. The neutralized solution was then sonicated under a nitrogen atmosphere and ice-water bath protection for approximately 6 h. After sonication, the solution was centrifuged at 3500 rpm for 30 min. A stable dark-green supernatant containing single-layer Ti 3 C 2 Tx MXene was obtained. Finally, the supernatant was freeze-dried and stored under vacuum for future use. 2.4 Preparation of PANI-Modified Short Carbon Nanofibers. Aniline hydrochloride solution was prepared by dissolving 1 mL of aniline in 100 mL of 1 M HCl. A carbon nanofiber membrane ( 2.0 × 2.0 cm) was gradually immersed into an aniline hydrochloride solution. After 15 min of immersion, 20 mL of 1 M ammonium persulfate (APS) solution was added to the reaction system, followed by vigorous stirring. The mixture was subsequently refrigerated at 4°C for 6 h. The CNF membrane was removed from the solution and thoroughly rinsed with a water/ethanol (1:1, v/v) mixture. The samples were then dried at 70°C for 12 h in a vacuum oven. Finally, the dried CNF was broken into short fibers through mechanical fragmentation to obtain polyaniline (PANI)-modified carbon nanofibers. 2.5 Preparation of MXene/SCNF@PANI hybrid Nanofiber Membranes MXene nanosheets were dispersed in deionized water through 30-minute ultrasonication to prepare a 1 mg mL − 1 MXene suspension. Simultaneously, the SCNF@PANI composite material was dispersed in deionized water under identical ultrasonication conditions to obtain a 1 mg mL − 1 SCNF@PANI suspension. Four hybrid suspensions with mass ratios of MXene to SCNF@PANI of 1:3, 1:2, 1:1, and 2:1 were prepared while maintaining a constant total mass of 40 mg for each mixture. Each hybrid suspension was vacuum-filtered through a filtration membrane (0.22 µm pore size, polyvinylidene fluoride) using a Buchner funnel apparatus, during which the MXene nanosheets and SCNF@PANI were co-assembled into uniform hybrid nanofiber membranes on the membrane surface. After filtration, the hybrid membranes were carefully peeled off from the filtration membrane and vacuum-dried at 60°C for 12 h. The resulting membranes were designated MSCPM1, MSCPM2, MSCPM3, and MSCPM4, corresponding to the increasing MXene content in the respective mass ratios. A flowchart of the preparation process is shown in Fig. 1 . 3. Characterization 3.1 Morphological Examination In this experiment, a scanning electron microscope (SEM, S-3400, Hitachi Inc., Japan) was used to characterize the micro-morphology of the samples by analyzing the SEM images. Information such as the samples' surface morphology, particle size, and pore structure was obtained with additional elemental analysis conducted through EDS to identify constituents such as C, N, and Ti. 3.2 X-ray Photoelectron Spectroscopy Test This experiment utilized X-ray photoelectron spectroscopy (XPS, Thermo Scientific K-Alpha) was used to characterize the surface chemical composition, chemical state, and electronic structure of the samples. The test employed monochromatic Al Kα radiation (hv = 1486.6 eV) as the excitation source, and the binding energy was calibrated against the reference C 1s peak (284.8 eV). 3.3 Thermogravimetric Analysis The thermal stability of the sample was characterized using a thermogravimetric analyzer (TGA, TGA4000). 3.4 Wettability Performance Analysis In this experiment, an optical contact angle meter (DSA30) was used to characterize the wettability of the samples. 3.5 Electrochemical Performance Testing 3.5.1 Three-Electrode Test System Cyclic Voltammetry Test In this study, cyclic voltammetry (CV) was employed to characterize the electrochemical performance of the MCNF membrane. A 1 cm × 0.5 cm MCNF membrane was used as the working electrode, a 1 mol L − 1 dilute sulfuric acid solution served as the electrolyte, a platinum sheet electrode was chosen as the auxiliary electrode, and an Ag/AgCl electrode was selected as the reference electrode to construct the three-electrode system. The tests were conducted on an electrochemical workstation (CHI660E), with the potential window set between − 0.4 to 0.4 V and scan rates of 10, 20, 50, 100, 200, 500, and 1000 mV s − 1 . By recording the CV curves at different scan rates, the capacitance behavior and electrochemical reaction kinetics of the MCNF membrane were determined. After obtaining the data, the mass-specific capacitance of the sample was calculated using Formula 1: where C is the mass-specific capacitance (F g − 1 ), v is the scan rate (mV s − 1 ), I is the discharge current (A), m is the mass of the active material on the working electrode (g), and ΔV is the working voltage window (V). Electrochemical impedance testing This experiment employed EIS technology to study the interfacial properties and charge transport behavior of MCNF thin membranes. The test system was the same as that used for the CV. Two-Electrode Test System The test used two pieces of MCNF with the same mass and size as the working electrode and counter electrode in a 1 mol L − 1 H 2 SO 4 solution. Constant Current Charge-Discharge Test The GCD test applies a constant current to the electrode, causing the device to charge and discharge within a set voltage range. The energy storage performance was evaluated using the GCD curve. Cycling Stability Test To study the long-term stability of the MCNF-based supercapacitors, a charge-discharge cycling test was conducted for 10,000 cycles at a current density of 1 A g − 1 . 4. Results and discussion 4.1 Morphological Examination To investigate the structure-property relationships of MXene/SCNF@PANI hybrid nanofiber membranes, morphological and elemental distribution analyses were systematically performed via SEM and EDS on hybrid nanofiber membranes with varying mass ratios (MSCPM1-MSCPM4) and pristine SCNF@PANI. As shown in Fig. 2 e, SCNF@PANI exhibited a distinctive core-shell architecture, where the carbon nanofiber surfaces were uniformly coated with a PANI nanoparticle layer, confirming PANI's successful in situ polymerization of PANI on the fiber surfaces. Notably, this core-shell structure not only preserved the porous characteristics of the carbon fibers but also established a continuous conductive network through the PANI coating. The SEM image of MSCPM1 (MXene: SCNF@PANI = 1:3, Fig. 2 a) displays a loosely interconnected fibrous network. MXene nanosheets were sparsely distributed within the fiber interstices, accompanied by localized agglomeration of PANI. This heterogeneous distribution was attributed to the limited dispersibility of MXene at low mass ratios, which hindered its effective integration into the fibrous framework of the scaffold. Nevertheless, the porous channels formed between the fibers facilitated electrolyte infiltration. When the MXene ratio was increased to 1:2 (MSCPM2, Fig. 2 b), a structural evolution was observed: MXene nanosheets were found to interpenetrate the fibrous network, forming localized two-dimensional/one-dimensional interpenetrating architectures. This transition suggests that the enhanced MXene content promoted interfacial interactions between the MXene nanosheets and the PANI-coated fibers, thereby improving the structural compactness. Interestingly, partial delamination of the PANI layer from the fiber surfaces was detected, indicating potential limitations in interfacial adhesion under high shear stress during processing. Further optimization at a 1:1 mass ratio (MSCPM3, Fig. 2 c) yielded an ideal three-dimensional porous network: MXene nanosheets were oriented at angles of approximately 60°–120° relative to the fiber skeleton, creating hierarchical porosity, whereas PANI nanoparticles were uniformly anchored on both the fiber and MXene surfaces, forming a continuous conductive coating. This hierarchical architecture maintained the mechanical integrity of the carbon fiber framework and achieved multiscale synergy through the 2D conductive network of MXene and PANI’s pseudocapacitive active sites of PANI. EDS elemental mapping (Fig. 2 f) demonstrated the homogeneous distribution of C, N, and Ti elements. Specifically, N (characteristic of PANI) was enriched in the fibrous regions, whereas Ti (indicative of MXene) was concentrated in the lamellar domains, confirming the spatially complementary distribution of the ternary components. These elemental patterns validated the successful construction of hybrid nanofiber membranes and elucidated the synergistic mechanisms among the components at the microscale. 4.2 XPS Analysis XPS was employed to perform fingerprint analysis of the elemental composition and chemical states to explore the chemical structure-property relationships of MXene/SCNF@PANI ternary hybrid nanofiber membranes (MSCPM3). As shown in Fig. 4 - 3 a, the characteristic peaks of C 1s (284.8 eV), Ti 2p (454.9 eV), O 1s (531.2 eV), and N 1s (399.7 eV) were captured in the survey spectrum, indicating the typical characteristics of the MXene/SCNF@PANI composite system. Notably, the presence of the Ti 2p signal directly demonstrated the successful incorporation of two-dimensional MXene nanosheets, whereas the N 1s peak confirmed the effective loading of the conductive polymer PANI. C 1s spectra (Fig. 3 b) exhibited multi-peak fitting characteristics, revealing the complex carbon chemical environment of the material. The main peak at 284.8 eV (C-C/C = C bonds) was attributed to the graphitic framework of the carbon fibers and the conjugated structure of PANI. The secondary peak at 286.16 eV (C-O bonds) originated from oxygen-containing functional groups on the carbon fiber surface or the MXene-C-Ti-O interfacial bonds. The shoulder peak at 287.67 eV (C = O bonds) is likely associated with carboxyl groups on the carbon fiber surface or carbonyl structures at the edges of MXene. Notably, the weak peak at 281.61 eV corresponding to C-Ti bonds provided the first evidence of chemical bonding between MXene, SCNF, and polyaniline (PANI). The formation of such heterointerfacial bonds significantly enhances the structural integrity of the ternary system and provides direct pathways for electron transport. The Ti 2p spectrum (Fig. 3 c) exhibited the typical double-peak structure of MXene, with peaks at 459.13 and 465.01 eV corresponding to the Ti 2p 3/2 and Ti 2p 1/2 signals of Ti-C bonds, respectively, confirming the retention of the layered structure of Ti3C2Tx. Notably, the satellite peaks at 454.97 and 461.01 eV, corresponding to Ti-O bonds, indicated the partial surface oxidation of MXene. In comparison, the Ti-OH bond signal at 456.08 eV indicates hydroxylation modification of the MXene surface. This surface hydroxylation not only improved the wettability of the material but also provided additional adsorption sites for the electrolyte ions. The N 1s spectrum (Fig. 3 d) showed fitting results with a main peak at 399.74 eV corresponding to -C-N- bonds in PANI, indicating the successful polymerization of aniline monomers into polyaniline. The characteristic peak at 401.83 eV was attributed to PANI's polaronic state of PANI (-N⁺=), confirming the presence of conductive emeraldine salt structures. This oxidation state distribution enabled PANI to contribute pseudo-capacitance via rapid proton doping/de-doping reactions during charge/discharge processes, while its conjugated structure synergistically enhanced the overall conductivity of the material through interaction with the conductive network formed by carbon fibers and MXene XPS analysis indicated that MXene, SCNF, and PANI formed a good chemical composite in the MXene/SCNF@PANI hybrid nanofiber membrane. The chemical bonding between MXene and SCNF@PANI enhanced the interfacial binding force and the structural stability. The introduction of PANI improves the conductivity and pseudocapacitive performance, whereas the surface hydroxylation of MXene may optimize the wettability and electrochemical performance. 4.3 TG Analysis To investigate the thermal stability of the MXene/SCNF@PANI hybrid nanofiber membranes (MSCPM3), TG was performed on MSCPM1, MSCPM2, MSCPM3, and MSCPM4 samples. The TG curve revealed three distinct stages of mass loss during the heating process, as shown in Fig. 4 . In the first stage (0–150°C), the initial mass loss of the four samples was mainly attributed to the volatilization of adsorbed moisture and residual solvents. The hydrophilic functional groups (such as -OH and -O) on the MXene and SCNF@PANI surfaces facilitated the adsorption of ambient moisture, resulting in significant weight loss at low temperatures. This observation is consistent with the presence of Ti-OH and C-O bonds identified in the XPS analysis, further confirming the hydrophilic nature of the hybrid nanofiber membrane. In the second stage (150–350°C), the quality loss was attributed to the removal of residual impurities, such as Li⁺, F⁻, and Al³⁺ from the MXene synthesis process, as well as unreacted hydrochloric acid and sodium dodecylbenzene sulfonate from PANI polymerization. These impurities were eliminated within the temperature range of 150–350°C, contributing to the observed mass reduction. Additionally, the decomposition of unstable surface functional groups (such as hydroxyl and carboxyl groups) on MXene and SCNF may have further contributed to mass loss in this stage. In the third stage (350–600°C), the final stage of mass loss was primarily attributed to the thermal degradation of PANI. Above 350°C, PANI began to deactivate, with its molecular chain structure disintegrating progressively until complete decomposition near 600°C. Despite the thermal degradation of PANI, MSCPM3 retained 86% of its mass, indicating excellent stability at high temperatures. The residual mass (> 80%) was primarily attributed to the Ti₃C₂Tₓ matrix, which remained stable up to a critical temperature of over 3000°C. The lower proportion of MXene in MSCPM1 and MSCPM2 resulted in a more significant impact of PANI thermal degradation on the overall mass loss of the composites. In contrast, MSCPM3 and MSCPM4 exhibited better stability owing to their higher MXene content. Among them, MSCPM3 exhibited optimal thermal stability. At a 1:1 mass ratio, good chemical bonds (e.g., C-Ti and Ti-O) were formed between MXene and SCNF@PANI, which significantly enhanced the interfacial bonding and structural integrity of the sample and effectively prevented material decomposition and loss at elevated temperatures. However, the excessively high proportion of MXene in MSCPM4 may have prevented uniform chemical bonding with SCNF@PANI, thereby weakening the overall structural stability and electrochemical performance of the sample. 4.4 Wettability Performance Analysis To investigate the wettability of the MXene/SCNF@PANI composite membranes, dynamic water contact angle measurements were performed on MSCPM1, MSCPM2, MSCPM3, and MSCPM4, with water contact angles recorded over a 0–7 s interval. As shown in Fig. 5 , water droplets were observed to spread completely on the surfaces of MSCPM2 and MSCPM4 within 7 s, with contact angles approaching 0°. In contrast, water droplets achieved complete spreading on the surface of MSCPM3 within only 3 s, resulting in contact angles approaching 0°. Simultaneously, MSCPM2 and MSCPM4 exhibited favorable wettability, and complete droplet spreading required a longer duration (7 s). The occurrence of this phenomenon in MSCPM2 is attributed to the fact that although the MXene and SCNF composite enhances hydrophilicity, the distribution and quantity of surface functional groups are insufficient to achieve rapid wetting. The hydroxyl (-OH) and ether (-O-) functional groups of MXene, combined with the porous structure of SCNF, provide favorable conditions for water molecule spreading; however, the wetting rate remains relatively slow. Due to the hydrophilic properties of MXene, MSCPM4 theoretically exhibits the best wettability. However, an excessively high MXene ratio may lead to insufficiently uniform binding with SCNF@PANI, resulting in a less dense distribution of hydrophilic groups in certain regions, thereby affecting the overall wettability. Although a higher MXene content enhances the mechanical strength and thermal stability of the material to some extent, it may also hinder the rapid transport of electrolyte ions within the porous structure, as excessive MXene nanosheets may stack or cover some pores, limiting the electrolyte penetration pathways. MSCPM1 demonstrated the poorest wetting performance, with a slow droplet spreading speed. The MXene content was the lowest, with a ratio of 1:3 relative to SCNF@PANI, leading to the lowest density of hydrophilic groups and an inability to effectively improve the hydrophilicity of the composite membrane. In comparison, the wettability of MSCPM3 was significantly improved, with water droplets spreading completely within 3 seconds. This enhancement was attributed to the presence of polar functional groups (such as -NH- and -N=) on the surface of the conductive polymer PANI, which significantly increased the surface energy of the material and thereby enhanced wettability. The synergistic effect of MXene, SCNF, and PANI further optimized the surface structure of the composite membrane, facilitating stronger interactions with water molecules. The combined contributions of the hydroxyl and ether functional groups of MXene, SCNF’s porous structure of SCNF, and PANI’s polar functional groups of PANI resulted in a marked improvement in the wettability of the composite membrane. This superior wettability implies that the electrolyte can rapidly penetrate the internal structure of the composite membrane, thereby increasing the effective contact area between the electrode material and electrolyte. Such rapid penetration promotes fast ion transport and diffusion, thereby enhancing the electrochemical activity of the electrode materials. 4.5 Electrochemical Performance Analysis 4.5.1 Study on the Electrochemical Performance of the Three-Electrode System The CV and EIS measurements were performed using a three-electrode configuration to systematically evaluate the electrochemical performance of MXene/SCNF@PANI hybrid nanofiber membranes. A 1 M H₂SO₄ aqueous solution was employed as the electrolyte, with a potential window set between − 0.4 and 0.4 V (vs. Ag/AgCl). As shown in Fig. 6 a, the CV curves of the electrodes at a scan rate of 5 mV s⁻¹ exhibited distinct redox peaks (oxidation peak at ~ 0.2 V and reduction peak at ~-0.1 V), which were attributed to the quinone/benzenoid redox transitions of PANI (Eq. 1 ). Notably, the enclosed area of the CV curve for MSCPM3 was the largest, yielding an integrated capacitance value of 1.23 mF cm⁻², which was significantly higher than those of MSCPM1 (0.58 mF cm⁻²), MSCPM2 (0.89 mF cm⁻²), and MSCPM4 (1.02 mF cm⁻²). This performance difference directly reflects the optimization degree of the ternary synergistic effect, with the 1:1 MXene: SCNF@PANI ratio in MSCPM3 achieving the highest charge storage capacity. The specific capacitance based on the CV data was calculated using Eq. 1 , revealing that MSCPM3 achieved a gravimetric capacitance of 601.8 F g⁻¹ at 5 mV s⁻¹, representing a 55.4% improvement over the pristine MXene/SCNF membrane (387.2 F g⁻¹) (Fig. 6 b). This enhancement was attributed to the pseudocapacitive contribution of PANI (~ 350 F g⁻¹) combined with the double-layer capacitance of MXene/SCNF. Remarkably, even at a scan rate of 100 mV s⁻¹, MSCPM3 retained a specific capacitance of 425.3 F g⁻¹, demonstrating an excellent rate capability. This can be attributed to the hierarchical porous structure of MSCPM3, which facilitates efficient ion transport and diffusion. EIS measurements further elucidated the charge-transfer characteristics of the materials. As shown in Fig. 6 c, the equivalent series resistance (Rs) of MSCPM3 was 5.38 Ω, representing a 25.4% reduction compared to that of MSCPM1 (7.21 Ω), while the charge transfer resistance (Rct) decreased by 41.3% to 3.85 Ω. The diameter of the semicircle in the high-frequency region (10⁵ Hz) for MSCPM3 was only 60% of that of MSCPM1, indicating more efficient interfacial charge transfer. In the low-frequency region (0.01 Hz), the Warburg impedance slope (Z' vs. ω⁻¹/²) of MSCPM3 was 1.23 Ω s⁻¹/², which was significantly lower than that of MSCPM1 (1.85 Ω s⁻¹/²), corresponding to a higher ionic diffusion coefficient (D = 1.58×10⁻ 10 cm² s⁻¹). This multiscale synergistic mechanism provides a kinetic foundation for the superior electrochemical performance of MSCPM3. 4.5.2 Study on the Electrochemical Performance of a Two-Electrode System To further evaluate the practical performance of the MXene/SCNF@PANI hybrid nanofiber membranes, symmetric supercapacitors were assembled using two MSCPM3 electrodes of identical dimensions and tested in a two-electrode configuration with 1 mol/L H₂SO₄ as the electrolyte. GCD and cyclic stability tests were performed to assess the electrochemical behavior of the cells. Figure 7 a presents the GCD curves of MSCPM3 electrodes at various current densities (1 A g⁻¹ to 5 A g ⁻ 1 ). The curves exhibited quasi-triangular profiles without significant voltage drops, indicating excellent capacitive behavior and rapid charge storage kinetics. However, slight deviations from the ideal triangular shapes were observed, which were primarily attributed to the pseudocapacitive contributions of PANI. During the charge-discharge cycles, redox reactions in PANI introduced additional pseudo-capacitance alongside double-layer capacitance, leading to the observed deviations. This pseudocapacitive behavior further enhances the electrochemical performance of the hybrid nanofiber membrane. Figure 7 b illustrates the cyclic stability of the MSCPM3-based supercapacitors tested at 1 A g⁻¹. After 10,000 charge-discharge cycles, the device retained 81.5% of its initial capacitance, demonstrating remarkable cycling stability. This stability was attributed to the chemical bonding between MXene and SCNF@PANI, which reinforced the structural integrity of the hybrid nanofiber membrane and prevented the degradation or failure of the electrode material during cycling. Additionally, the optimized interfacial properties of the composite reduced the interfacial resistance and polarization, further enhancing durability. The superior performance of MSCPM3 in GCD and cyclic stability tests underscores the practical potential of MXene/SCNF@PANI hybrid nanofiber membranes in supercapacitor applications. 5. Conclusions This study synthesized a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid nanofiber membrane (MSCPM3) via chemical oxidative polymerization and vacuum-assisted filtration, integrating MXene, short carbon nanofibers (SCNF), and polyaniline (PANI). With an optimized MXene:SCNF@PANI mass ratio of 1:1, MSCPM3 formed a uniform 3D porous structure with homogeneous C, N, Ti distribution, and C-Ti/Ti-O covalent bonds between components. It achieved a record specific capacitance of 601.8 F g⁻¹ at 5 mV s⁻¹ (surpassing most MXene-based hybrids), low equivalent series resistance (5.38 Ω) and charge transfer resistance (3.85 Ω), rapid water spreading (3 s, contact angle ≈ 0°), and 81.5% capacitance retention after 10,000 cycles. The high performance of MSCPM3 stems from multi-scale synergy: SCNF’s porous 1D framework suppresses MXene restacking and enhances mechanical stability; MXene’s 2D conductive network (10⁴–10⁵ S cm⁻¹) compensates for PANI’s low conductivity (10⁻³–100 S cm⁻¹); PANI’s redox-active sites provide pseudo-capacitance (300–500 F g⁻¹) to complement MXene/CNF’s EDLC. XPS-verified C-Ti/Ti-O bonds reduce interfacial resistance and prevent component detachment, while synergistic hydrophilic groups (-OH in MXene, -NH-/-N = in PANI) and SCNF porosity accelerate electrolyte infiltration. This work provides a scalable strategy for high-performance supercapacitor electrodes, advancing MXene integration with carbon nanomaterials and conductive polymers. Future research should optimize membrane thickness and explore scalability for flexible/high-temperature devices. Declarations Author Contributions Zhengyu Ding : Conceptualization, Methodology, Formal analysis, Investigation, Resources, Data curation, Writing original draft, Visualization. Maoyu You : Data curation, Writing original draft, Methodology, Writing review & editing. Binjie Xin : Validation, Writing review & editing, Supervision, Project administration. Md All Amin Newton: Writing review & editing. All authors reviewed the manuscript. Acknowledgments This work was supported by the Project of Local University Ability Building of Shanghai Scientific and Technological Committee (19030501200). Conflicts of interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. Data availability Data will be made available on request. References Li X, Huang Z, Shuck CE, et al (2022) MXene chemistry, electrochemistry and energy storage applications. Nature Reviews Chemistry 6:389–404. https://doi.org/10.1038/s41570-022-00384-8 Gao M, Wang F, Yang S, et al (2023) Engineered 2D MXene-based materials for advanced supercapacitors and micro-supercapacitors. Materials Today. https://doi.org/10.1016/j.mattod.2023.12.009 Yuan T, Zhang Z, Liu Q, et al (2023) MXene (Ti3C2Tx)/cellulose nanofiber/polyaniline film as a highly conductive and flexible electrode material for supercapacitors. Carbohydrate Polymers 304:120519. https://doi.org/10.1016/j.carbpol.2022.120519 Ahmad F, Shahzad A, Danish M, et al (2024) Recent developments in transition metal oxide-based electrode composites for supercapacitor applications. Journal of Energy Storage 81:110430. https://doi.org/10.1016/j.est.2024.110430 Shin S-J, Gittins JW, Balhatchet CJ, et al (2023) Metal–Organic Framework Supercapacitors: Challenges and Opportunities. Advanced Functional Materials 34:. https://doi.org/10.1002/adfm.202308497 Hu A, Li F, Chen W, et al (2022) Ion Transport Kinetics in Low-Temperature Lithium Metal Batteries. Advanced Energy Materials 12:. https://doi.org/10.1002/aenm.202202432 Zheng J, Wang J, Qu J, et al (2022) CeO2/Ni-Al layered double hydroxide composite electrode for the enhancement of specific capacitance and capacitance retention performance. Applied Clay Science 216:106370. https://doi.org/10.1016/j.clay.2021.106370 Joseph A, Mathew A, Perikkathra S, Thomas T (2024) Recent advances in and perspectives on binder materials for supercapacitors–A review. European Polymer Journal 210:112941. https://doi.org/10.1016/j.eurpolymj.2024.112941 Levitt AS, Alhabeb M, Hatter CB, et al (2019) Electrospun MXene/carbon nanofibers as supercapacitor electrodes†. Journal of Materials Chemistry A 7:269–277. https://doi.org/10.1039/c8ta09810g Li L, Lu F, Xue R, et al (2019) Ultrastable Triazine-Based Covalent Organic Framework with an Interlayer Hydrogen Bonding for Supercapacitor Applications. ACS Appl Mater Interfaces 11:26355–26363. https://doi.org/10.1021/acsami.9b06867 Gupta S, Thacharakkal D, Subramaniam C, Ramakrishnan S (2024) Nanocarbon Florets with Synthetically Tunable Porosity as High-Rate Anodes for Li-ion Batteries. ACS Applied Nano Materials 7:27336–27343. https://doi.org/10.1021/acsanm.4c05368 Isacfranklin M, Yuvakkumar R, Ravi G, et al (2023) SmNiO3/SWCNT perovskite composite for hybrid supercapacitor. Journal of Energy Storage 68:107786. https://doi.org/10.1016/j.est.2023.107786 Komatsubara K, Suzuki H, Inoue H, et al (2022) Highly Oriented Carbon Nanotube Supercapacitors. ACS Applied Nano Materials. https://doi.org/10.1021/acsanm.1c04236 Zhai S, Chen Y (2022) Graphene-Based Fiber Supercapacitors. Accounts of Materials Research 3:922–934. https://doi.org/10.1021/accountsmr.2c00087 Pan Z, Cui B, Gong X, et al (2025) Zinc ion coordination doped polyaniline electrode for high performance supercapacitors. Journal of Energy Storage 120:116431. https://doi.org/10.1016/j.est.2025.116431 Tang D, Zhitomirsky I (2025) Synergy of Pseudocapacitive Properties of Ferromagnetic La1 – xSrxMnO3 and Polypyrrole in high Active Mass Composite Electrodes for Supercapacitors. Journal of Inorganic and Organometallic Polymers and Materials. https://doi.org/10.1007/s10904-025-03610-0 Yan W, Yan S, Cai D, et al (2025) Synthesis of MXene films with horizontally and vertically hierarchical pores for high-performance supercapacitors. Electrochimica Acta 146479. https://doi.org/10.1016/j.electacta.2025.146479 Jiang H, Yuan B, Guo H, et al (2024) Malleable, printable, bondable, and highly conductive MXene/liquid metal plasticine with improved wettability. Nature Communications 15:. https://doi.org/10.1038/s41467-024-50541-4 Lyu S, Chang H, Zhang L, et al (2023) High specific surface area MXene/SWCNT/cellulose nanofiber aerogel film as an electrode for flexible supercapacitors. Composites Part B: Engineering 264:110888. https://doi.org/10.1016/j.compositesb.2023.110888 Shi M, Wang R, He J, et al (2022) Multiple Redox-active Cyano-substituted Organic Compound Integrated with MXene for High-Performance Flexible Aqueous K-ion Battery. Chemical Engineering Journal 450:138238. https://doi.org/10.1016/j.cej.2022.138238 Ding L, Wei Y, Wang Y, et al (2017) A Two-Dimensional Lamellar Membrane: MXene Nanosheet Stacks. Angewandte Chemie International Edition 56:1825–1829. https://doi.org/10.1002/anie.201609306 Peng Y, Zhang X, Sun R, et al (2024) Review of electro-spun carbon nanofiber electrode materials for electrochemical capacitors. Journal of Materials Chemistry A 12:32566–32592. https://doi.org/10.1039/d4ta06221c Yan S, Jin S, He X, et al (2025) Direct synthesis of composite conductive carbon nanofiber aerogels with continuous internal networks for collaborative physiological signal monitoring under complex environments. Sensors and Actuators B: Chemical 426:136975. https://doi.org/10.1016/j.snb.2024.136975 Chen Y, Tu C, Liu Y, et al (2022) Microstructure and mechanical properties of carbon graphite composites reinforced by carbon nanofibers. Carbon Letters 33:561–571. https://doi.org/10.1007/s42823-022-00445-4 You M, Xin B (2024) MXene Nanosheets and Carbon Nanofiber Hybrid Membranes for Electrochemical Energy Storage Materials. Fibers Polym 25:3323–3330. https://doi.org/10.1007/s12221-024-00679-1 Schmidt A, Husmann S, Presser V, Zarbin AJG (2025) Transparent polyaniline/MXene thin films supercapacitors. Electrochimica Acta 146184. https://doi.org/10.1016/j.electacta.2025.146184 Chu J, Li X, Li Q, et al (2019) Hydrothermal synthesis of PANI nanowires for high-performance supercapacitor. High Performance Polymers 32:258–267. https://doi.org/10.1177/0954008319856664 Hwang H, Byun S, Yuk S, et al (2021) High-rate electrospun Ti3C2Tx MXene/carbon nanofiber electrodes for flexible supercapacitors. Applied Surface Science 556:149710. https://doi.org/10.1016/j.apsusc.2021.149710 Chen T, Li M, Li Y, et al (2023) Synthesis of hierarchical structure MXene/PANI composite hybrid electrodes for supercapacitors. Materials Science and Engineering: B 290:116354. https://doi.org/10.1016/j.mseb.2023.116354 Zhou X, Wang S, Ma G, et al (2024) Aniline-co-pyrrole (ANPY)/MXene composites with high specific capacitance for flexible supercapacitors. Journal of Energy Storage 97:112951. https://doi.org/10.1016/j.est.2024.112951 Donthula K, Malothu UR, Araga R, et al (2023) Flexible polyaniline/MXene/CNF composite nanofibrous mats as high-performance supercapacitor electrodes. Polymer Composites 44:7571–7584. https://doi.org/10.1002/pc.27646 Yang J, Yang Y, Lan J, et al (2019) Polyaniline-manganese dioxide-carbon nanofiber ternary composites with enhanced electrochemical performance for supercapacitors. Journal of Electroanalytical Chemistry 843:22–30. https://doi.org/10.1016/j.jelechem.2019.04.073 Fazal A, Zafar MM, Iqbal MJ, et al (2025) High-performance supercapacitor electrode synthesized by in-situ chemical oxidative polymerization of TiO2/PANI composite. Synthetic Metals 311:117842. https://doi.org/10.1016/j.synthmet.2025.117842 Wang J, He J, Kan D, et al (2022) MXene Film Prepared by Vacuum-Assisted Filtration: Properties and Applications. Crystals 12:1034. https://doi.org/10.3390/cryst12081034 Li W, Farhadi B, Liu M, et al (2025) Interface engineering based NiCoMoO4/Ti3C2Tx MXene heterostructure for high-performance flexible supercapacitors. Journal of Colloid and Interface Science 677:541–550. https://doi.org/10.1016/j.jcis.2024.08.093 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 09 Sep, 2025 Reviews received at journal 07 Sep, 2025 Reviews received at journal 07 Sep, 2025 Reviews received at journal 03 Sep, 2025 Reviews received at journal 02 Sep, 2025 Reviewers agreed at journal 31 Aug, 2025 Reviews received at journal 30 Aug, 2025 Reviewers agreed at journal 28 Aug, 2025 Reviewers agreed at journal 28 Aug, 2025 Reviewers agreed at journal 28 Aug, 2025 Reviewers agreed at journal 28 Aug, 2025 Reviewers invited by journal 28 Aug, 2025 Editor assigned by journal 27 Aug, 2025 Submission checks completed at journal 27 Aug, 2025 First submitted to journal 23 Aug, 2025 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-7440091","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":509558123,"identity":"7db8df03-483a-47ca-b523-5f7a8e24ad99","order_by":0,"name":"Zhengyu Ding","email":"","orcid":"","institution":"Shanghai University of Engineering Science","correspondingAuthor":false,"prefix":"","firstName":"Zhengyu","middleName":"","lastName":"Ding","suffix":""},{"id":509558127,"identity":"02f49592-0f70-434c-a24e-437339314cd4","order_by":1,"name":"Maoyu You","email":"","orcid":"","institution":"Shanghai University of Engineering Science","correspondingAuthor":false,"prefix":"","firstName":"Maoyu","middleName":"","lastName":"You","suffix":""},{"id":509558129,"identity":"6177dbe4-081a-4ec4-932e-9bb1c2e0dbf8","order_by":2,"name":"Binjie Xin","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAAyklEQVRIiWNgGAWjYDACZgY2BokKKIeHeC1nSNLCANTC2EaKFoPjvMceWM6rS+znP8D44G0bg7w5IS2SzXzpBpLbDifOnJHAbDi3jcFwZwMBLfzMPGYSktsOJG64wcAmzdvGkGBwgIAWNrCWOXWJ+88fYP9NlBaILQ3MiRsYEtiYidIi2cxjbiBx7LDxjBuJzZJzzkkYbiCkxeD8GbPHEjV1sv39hw9+eFNmI0/QFhBglgBTjA1AQoII9SC1H4hTNwpGwSgYBSMVAAAAVDgHkRyTqAAAAABJRU5ErkJggg==","orcid":"","institution":"Shanghai University of Engineering Science","correspondingAuthor":true,"prefix":"","firstName":"Binjie","middleName":"","lastName":"Xin","suffix":""},{"id":509558131,"identity":"d3c49e06-099d-43d4-b94f-164a3fd73452","order_by":3,"name":"Md All Amin Newton","email":"","orcid":"","institution":"Shanghai University of Engineering Science","correspondingAuthor":false,"prefix":"","firstName":"Md","middleName":"All Amin","lastName":"Newton","suffix":""}],"badges":[],"createdAt":"2025-08-23 09:08:26","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7440091/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7440091/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":90603234,"identity":"71b618e9-167d-4089-a711-46ce54a97e56","added_by":"auto","created_at":"2025-09-04 15:03:09","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":261487,"visible":true,"origin":"","legend":"\u003cp\u003ePreparation flowchart of MXene/SCNF@PANI hybrid \u003cstrong\u003en\u003c/strong\u003eanofiber membrane\u003c/p\u003e","description":"","filename":"image1.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/c23279e5a392e8e8fcdf5e7d.png"},{"id":90604488,"identity":"ad023762-4a4d-45cd-a8d4-35fc51b28ba9","added_by":"auto","created_at":"2025-09-04 15:19:09","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":502836,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of (a) MSCPM1 (b) MSCPM2 (c) MSCPM3 (d) MSCPM4 (e) SCNF@PANI，(f) EDS elemental maps of MSCNF3\u003c/p\u003e","description":"","filename":"image3.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/1803c9ef44aeec7b22ad9a33.png"},{"id":90603235,"identity":"bb6d2edf-9556-4713-b8ad-35214e54ae5a","added_by":"auto","created_at":"2025-09-04 15:03:09","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":243307,"visible":true,"origin":"","legend":"\u003cp\u003e(a) XPS survey spectrum，(b) C 1s，(c) Ti 2p and (d) N 1s spectra of MSCPM3\u003c/p\u003e","description":"","filename":"image4.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/534edb2a04d09357b780ef0d.png"},{"id":90604183,"identity":"502b2cfd-d847-40d3-af0f-ea3b30d6031c","added_by":"auto","created_at":"2025-09-04 15:11:09","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":313021,"visible":true,"origin":"","legend":"\u003cp\u003eThermogravimetric curve of MSCPM1, MSCPM2, MSCPM3, and MSCPM4.\u003c/p\u003e","description":"","filename":"image5.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/d8259af9d34b97a871396f10.png"},{"id":90604182,"identity":"5e0a6b59-d3fb-4858-ad23-b99d191a6c34","added_by":"auto","created_at":"2025-09-04 15:11:09","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":190399,"visible":true,"origin":"","legend":"\u003cp\u003eApparent water contact angle of MSCNF1, MSCNF2, MSCNF3 and MSCPM4\u003c/p\u003e","description":"","filename":"image6.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/3bed311b82ff538cb00f432b.png"},{"id":90603241,"identity":"92ce1fc8-7631-45e2-971a-304d52a594d7","added_by":"auto","created_at":"2025-09-04 15:03:09","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":158617,"visible":true,"origin":"","legend":"\u003cp\u003e(a) CV curves of MSCPM with different doping ratios (b) Specific capacitance of MSCPM3 (d) Nyquist plots of MSCPM1 and MSCPM3\u003c/p\u003e","description":"","filename":"image7.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/8f4cdeb8a70d584934a611a0.png"},{"id":90603237,"identity":"afe6d25d-1a0f-4bf4-80cf-223ed05144ee","added_by":"auto","created_at":"2025-09-04 15:03:09","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":115355,"visible":true,"origin":"","legend":"\u003cp\u003e(a) GCD curve of MSCPM3 (b) Capacitance retention curve of MSCPM3\u003c/p\u003e","description":"","filename":"image8.png","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/7a3ec0be4c962baf18d52d60.png"},{"id":90605844,"identity":"2971d5b7-2303-479b-96df-952d36f73524","added_by":"auto","created_at":"2025-09-04 15:35:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2489671,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7440091/v1/db21a5ee-53b9-4f3d-9aea-855a0fcbb36e.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eIn recent decades, owing to energy shortages and the development of modern energy storage technologies, energy storage systems[\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] have garnered significant attention in both academic and industrial circles as an essential intermediate step for efficient energy utilization. Supercapacitors, a key energy storage technology[\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], have gained attention owing to their high power density, fast charging/discharging ability, and long cycle life[\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], filling the gap between traditional capacitors and batteries. Energy is stored in these devices mainly through two mechanisms: EDLC at the electrode-electrolyte interface[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] and pseudo-capacitance from rapid, reversible redox reactions[\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. However, their relatively low energy density compared to batteries and electrode-material-design challenges (e.g., restricted ion transport capacity[\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], low specific capacitance[\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], and inadequate mechanical strength[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]) hinder their widespread use. Therefore, there is an urgent need for advanced electrode materials with hierarchical nanostructures and tailored properties.\u003c/p\u003e\u003cp\u003eElectrospinning is regarded as a powerful tool for fabricating nanostructured supercapacitor electrodes owing to its versatility and scalability[\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Continuous nanofibers with a high specific surface area[\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], tunable porosity[\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], and customizable composition, which are all critical for improving electrochemical performance, can be produced using this method. Additionally, electrospinning can integrate diverse materials, such as carbon-based materials, metal oxides, conductive polymers, and hybrid composites[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], into hierarchical structures.\u003c/p\u003e\u003cp\u003eTraditional carbon-based materials (e.g., carbon nanotubes[\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] and graphene[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]) and conductive polymers (e.g., polyaniline[\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] and polypyrrole[\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]) have been widely explored. However, their practical application is limited by insufficient pseudo-capacitance or poor cycling stability. Recently, MXene materials (e.g., Ti₃C₂Tx), a family of two-dimensional transition metal carbides[\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], have garnered attention for their metallic conductivity[\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e](up to 10⁴\u0026ndash;10⁵ S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), high surface area[\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e](200\u0026ndash;300 m\u0026sup2; g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), and redox-active surface terminations[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e](\u0026ndash;O,\u0026ndash;OH). Despite these advantages, MXene-based electrodes often suffer from the restacking of nanosheets[\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], which reduces ion accessibility and compromises mechanical flexibility.\u003c/p\u003e\u003cp\u003eCarbon nanofibers (CNFs)[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e, \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] have been proposed as promising structural reinforcements owing to their one-dimensional porous architecture and exceptional tensile strength (\u0026gt;\u0026thinsp;1.5 GPa)[\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. However, CNFs alone lack sufficient pseudo-capacitance for high-energy storage applications[\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Conductive polymers, such as polyaniline (PANI)[\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], provide pseudo-capacitance through reversible redox reactions (300\u0026ndash;500 F g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) but suffer from low electrical conductivity (10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e\u0026ndash;10\u003csup\u003e0\u003c/sup\u003e S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) and poor long-term stability[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Integrating MXene, CNFs, and PANI into a ternary composite presents an opportunity to address these limitations through hierarchical synergy. While binary systems (e.g., MXene/CNF[\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] or MXene/PANI[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e, \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]) have been reported, ternary systems[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e, \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] with covalent interfacial bonds (e.g., C-Ti and Ti-O) remain underexplored. These bonds are critical for enhancing the charge transfer efficiency and structural integrity.\u003c/p\u003e\u003cp\u003eIn this study, a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid membrane was synthesized via chemical oxidative polymerization[\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e] and vacuum-assisted filtration[\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. By optimizing the mass ratio of MXene to short carbon nanofiber@polyaniline (SCNF@PANI), a three-dimensional hierarchical architecture was achieved, in which MXene nanosheets interlocked with PANI-coated CNFs to form covalent interface bonds. This design leverages (1) the metallic conductivity of MXenes for rapid electron transport, (2) CNFs' mechanical rigidity of CNFs to maintain structural integrity, and (3) PANI's pseudo-capacitance of PANI for enhanced energy storage. The resulting composite exhibited a record-specific capacitance of 601.8 F g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 5 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, surpassing most reported MXene-based materials, while retaining 81.5% of its capacitance after 10,000 cycles. This work establishes a scalable strategy for overcoming the critical limitations of individual components through rational ternary design, providing new insights into interfacial engineering[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e] for the fabrication of high-performance flexible supercapacitors.\u003c/p\u003e"},{"header":"2. Experimental","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Materials.\u003c/h2\u003e\u003cp\u003ePolyacrylonitrile (PAN, with a molecular weight Mw\u0026thinsp;=\u0026thinsp;150,000g mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) was selected as the carbon nanofiber fabrication precursor and procured from Aladdin Reagent Company. N, N-Dimethylformamide (DMF, purity\u0026thinsp;\u0026ge;\u0026thinsp;99.8%) was used as the solvent for the spinning solution and was obtained from the China National Pharmaceutical Group Corporation. Ti ₃AlC₂ powder with a particle size of 400 mesh was obtained from 11 Technology Co, Ltd.. The etching solution was prepared using hydrochloric acid and lithium fluoride. Hydrochloric acid (HCl, with a mass fraction of 36\u0026ndash;38%) was acquired from the China National Chemicals Corporation, and lithium fluoride (LiF) was supplied by the Aladdin Reagent Company. Ammonium persulfate (APS) was used as an oxidizing agent to initiate the chemical oxidative polymerization of aniline (AN). APS and AN were obtained from the China National Pharmaceutical Group Corporation. All chemical reagents and materials used in the experiments were of analytical grade and were employed without further purification.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Preparation of Short Carbon Nanofibers.\u003c/h2\u003e\u003cp\u003eA PAN electrospinning solution with a weight percentage of 17% was prepared for electrospinning. Electrospinning was performed at a voltage of 15 kV, with a feed rate of 0.3 mm min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The receiving distance was maintained at 20 cm, and the aluminum foil was fixed on a rotating drum at a speed of 100 rpm. The resulting PAN nanofiber membrane was collected and subjected to pre-oxidation treatment. For this treatment, the fiber membrane samples were vertically suspended in a muffle furnace, with tin foil used as a counterweight to ensure the flatness of the sample. The temperature was increased at a rate of 1\u0026deg;C min\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e to 250\u0026deg;C, followed by a constant temperature hold for 120 min. Subsequently, the samples were naturally cooled to room temperature to obtain a pre-oxidized fiber membrane. Finally, the pre-oxidized nanofiber membrane was cut into small pieces and ground in a ball mill to produce short-CNFs.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Preparation of MXene Nanosheets.\u003c/h2\u003e\u003cp\u003eA single-layer Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003eTx MXene was synthesized by etching the MAX phase Ti\u003csub\u003e3\u003c/sub\u003eAlC\u003csub\u003e2\u003c/sub\u003e using LiF and HCl as etching agents. The experimental procedure was as follows: First, 1 g of LiF was mixed with 20 mL of 6 M HCl in a beaker, and the etching solution was prepared by stirring the mixture vigorously for 30 min. To avoid an intense exothermic reaction, 1 g of Ti\u003csub\u003e3\u003c/sub\u003eAlC\u003csub\u003e2\u003c/sub\u003e was added to the etching solution in portions over 8 min. The resulting mixture was then placed in a 35\u0026deg;C oil bath and stirred continuously for 48 h. Subsequently, the acidic suspension was washed with deionized (DI) water and centrifuged at 3500 rpm for 5\u0026ndash;8 cycles until the solution attained a neutral pH. The neutralized solution was then sonicated under a nitrogen atmosphere and ice-water bath protection for approximately 6 h. After sonication, the solution was centrifuged at 3500 rpm for 30 min. A stable dark-green supernatant containing single-layer Ti\u003csub\u003e3\u003c/sub\u003eC\u003csub\u003e2\u003c/sub\u003eTx MXene was obtained. Finally, the supernatant was freeze-dried and stored under vacuum for future use.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Preparation of PANI-Modified Short Carbon Nanofibers.\u003c/h2\u003e\u003cp\u003eAniline hydrochloride solution was prepared by dissolving 1 mL of aniline in 100 mL of 1 M HCl. A carbon nanofiber membrane ( 2.0 \u0026times; 2.0 cm) was gradually immersed into an aniline hydrochloride solution. After 15 min of immersion, 20 mL of 1 M ammonium persulfate (APS) solution was added to the reaction system, followed by vigorous stirring. The mixture was subsequently refrigerated at 4\u0026deg;C for 6 h. The CNF membrane was removed from the solution and thoroughly rinsed with a water/ethanol (1:1, v/v) mixture. The samples were then dried at 70\u0026deg;C for 12 h in a vacuum oven. Finally, the dried CNF was broken into short fibers through mechanical fragmentation to obtain polyaniline (PANI)-modified carbon nanofibers.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.5 Preparation of MXene/SCNF@PANI hybrid Nanofiber Membranes\u003c/h2\u003e\u003cp\u003eMXene nanosheets were dispersed in deionized water through 30-minute ultrasonication to prepare a 1 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e MXene suspension. Simultaneously, the SCNF@PANI composite material was dispersed in deionized water under identical ultrasonication conditions to obtain a 1 mg mL\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e SCNF@PANI suspension. Four hybrid suspensions with mass ratios of MXene to SCNF@PANI of 1:3, 1:2, 1:1, and 2:1 were prepared while maintaining a constant total mass of 40 mg for each mixture. Each hybrid suspension was vacuum-filtered through a filtration membrane (0.22 \u0026micro;m pore size, polyvinylidene fluoride) using a Buchner funnel apparatus, during which the MXene nanosheets and SCNF@PANI were co-assembled into uniform hybrid nanofiber membranes on the membrane surface. After filtration, the hybrid membranes were carefully peeled off from the filtration membrane and vacuum-dried at 60\u0026deg;C for 12 h. The resulting membranes were designated MSCPM1, MSCPM2, MSCPM3, and MSCPM4, corresponding to the increasing MXene content in the respective mass ratios. A flowchart of the preparation process is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Characterization","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e\u003ch2\u003e3.1 Morphological Examination\u003c/h2\u003e\u003cp\u003eIn this experiment, a scanning electron microscope (SEM, S-3400, Hitachi Inc., Japan) was used to characterize the micro-morphology of the samples by analyzing the SEM images. Information such as the samples' surface morphology, particle size, and pore structure was obtained with additional elemental analysis conducted through EDS to identify constituents such as C, N, and Ti.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec10\" class=\"Section2\"\u003e\u003ch2\u003e3.2 X-ray Photoelectron Spectroscopy Test\u003c/h2\u003e\u003cp\u003eThis experiment utilized X-ray photoelectron spectroscopy (XPS, Thermo Scientific K-Alpha) was used to characterize the surface chemical composition, chemical state, and electronic structure of the samples. The test employed monochromatic Al Kα radiation (hv\u0026thinsp;=\u0026thinsp;1486.6 eV) as the excitation source, and the binding energy was calibrated against the reference C 1s peak (284.8 eV).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec11\" class=\"Section2\"\u003e\u003ch2\u003e3.3 Thermogravimetric Analysis\u003c/h2\u003e\u003cp\u003eThe thermal stability of the sample was characterized using a thermogravimetric analyzer (TGA, TGA4000).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e\u003ch2\u003e3.4 Wettability Performance Analysis\u003c/h2\u003e\u003cp\u003eIn this experiment, an optical contact angle meter (DSA30) was used to characterize the wettability of the samples.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section2\"\u003e\u003ch2\u003e3.5 Electrochemical Performance Testing\u003c/h2\u003e\u003cdiv id=\"Sec14\" class=\"Section3\"\u003e\u003ch2\u003e3.5.1 Three-Electrode Test System\u003c/h2\u003e\u003cp\u003eCyclic Voltammetry Test\u003c/p\u003e\u003cp\u003eIn this study, cyclic voltammetry (CV) was employed to characterize the electrochemical performance of the MCNF membrane. A 1 cm \u0026times; 0.5 cm MCNF membrane was used as the working electrode, a 1 mol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e dilute sulfuric acid solution served as the electrolyte, a platinum sheet electrode was chosen as the auxiliary electrode, and an Ag/AgCl electrode was selected as the reference electrode to construct the three-electrode system. The tests were conducted on an electrochemical workstation (CHI660E), with the potential window set between \u0026minus;\u0026thinsp;0.4 to 0.4 V and scan rates of 10, 20, 50, 100, 200, 500, and 1000 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. By recording the CV curves at different scan rates, the capacitance behavior and electrochemical reaction kinetics of the MCNF membrane were determined. After obtaining the data, the mass-specific capacitance of the sample was calculated using Formula 1:\u003c/p\u003e\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\" width=\"319\" height=\"54\"\u003e\u003c/p\u003e\u003cp\u003ewhere C is the mass-specific capacitance (F g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), v is the scan rate (mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e), I is the discharge current (A), m is the mass of the active material on the working electrode (g), and ΔV is the working voltage window (V).\u003c/p\u003e\u003cp\u003eElectrochemical impedance testing\u003c/p\u003e\u003cp\u003eThis experiment employed EIS technology to study the interfacial properties and charge transport behavior of MCNF thin membranes. The test system was the same as that used for the CV.\u003c/p\u003e\u003cp\u003eTwo-Electrode Test System\u003c/p\u003e\u003cp\u003eThe test used two pieces of MCNF with the same mass and size as the working electrode and counter electrode in a 1 mol L\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e H\u003csub\u003e2\u003c/sub\u003eSO\u003csub\u003e4\u003c/sub\u003e solution.\u003c/p\u003e\u003cp\u003eConstant Current Charge-Discharge Test\u003c/p\u003e\u003cp\u003eThe GCD test applies a constant current to the electrode, causing the device to charge and discharge within a set voltage range. The energy storage performance was evaluated using the GCD curve.\u003c/p\u003e\u003cp\u003eCycling Stability Test\u003c/p\u003e\u003cp\u003eTo study the long-term stability of the MCNF-based supercapacitors, a charge-discharge cycling test was conducted for 10,000 cycles at a current density of 1 A g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"4. Results and discussion","content":"\u003cdiv id=\"Sec16\" class=\"Section2\"\u003e\u003ch2\u003e4.1 Morphological Examination\u003c/h2\u003e\u003cp\u003eTo investigate the structure-property relationships of MXene/SCNF@PANI hybrid nanofiber membranes, morphological and elemental distribution analyses were systematically performed via SEM and EDS on hybrid nanofiber membranes with varying mass ratios (MSCPM1-MSCPM4) and pristine SCNF@PANI. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ee, SCNF@PANI exhibited a distinctive core-shell architecture, where the carbon nanofiber surfaces were uniformly coated with a PANI nanoparticle layer, confirming PANI's successful in situ polymerization of PANI on the fiber surfaces. Notably, this core-shell structure not only preserved the porous characteristics of the carbon fibers but also established a continuous conductive network through the PANI coating. The SEM image of MSCPM1 (MXene: SCNF@PANI\u0026thinsp;=\u0026thinsp;1:3, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ea) displays a loosely interconnected fibrous network. MXene nanosheets were sparsely distributed within the fiber interstices, accompanied by localized agglomeration of PANI. This heterogeneous distribution was attributed to the limited dispersibility of MXene at low mass ratios, which hindered its effective integration into the fibrous framework of the scaffold.\u003c/p\u003e\u003cp\u003eNevertheless, the porous channels formed between the fibers facilitated electrolyte infiltration. When the MXene ratio was increased to 1:2 (MSCPM2, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003eb), a structural evolution was observed: MXene nanosheets were found to interpenetrate the fibrous network, forming localized two-dimensional/one-dimensional interpenetrating architectures. This transition suggests that the enhanced MXene content promoted interfacial interactions between the MXene nanosheets and the PANI-coated fibers, thereby improving the structural compactness. Interestingly, partial delamination of the PANI layer from the fiber surfaces was detected, indicating potential limitations in interfacial adhesion under high shear stress during processing. Further optimization at a 1:1 mass ratio (MSCPM3, Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ec) yielded an ideal three-dimensional porous network: MXene nanosheets were oriented at angles of approximately 60\u0026deg;\u0026ndash;120\u0026deg; relative to the fiber skeleton, creating hierarchical porosity, whereas PANI nanoparticles were uniformly anchored on both the fiber and MXene surfaces, forming a continuous conductive coating. This hierarchical architecture maintained the mechanical integrity of the carbon fiber framework and achieved multiscale synergy through the 2D conductive network of MXene and PANI\u0026rsquo;s pseudocapacitive active sites of PANI. EDS elemental mapping (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003ef) demonstrated the homogeneous distribution of C, N, and Ti elements. Specifically, N (characteristic of PANI) was enriched in the fibrous regions, whereas Ti (indicative of MXene) was concentrated in the lamellar domains, confirming the spatially complementary distribution of the ternary components. These elemental patterns validated the successful construction of hybrid nanofiber membranes and elucidated the synergistic mechanisms among the components at the microscale.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec17\" class=\"Section2\"\u003e\u003ch2\u003e4.2 XPS Analysis\u003c/h2\u003e\u003cp\u003eXPS was employed to perform fingerprint analysis of the elemental composition and chemical states to explore the chemical structure-property relationships of MXene/SCNF@PANI ternary hybrid nanofiber membranes (MSCPM3). As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e-\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ea, the characteristic peaks of C 1s (284.8 eV), Ti 2p (454.9 eV), O 1s (531.2 eV), and N 1s (399.7 eV) were captured in the survey spectrum, indicating the typical characteristics of the MXene/SCNF@PANI composite system. Notably, the presence of the Ti 2p signal directly demonstrated the successful incorporation of two-dimensional MXene nanosheets, whereas the N 1s peak confirmed the effective loading of the conductive polymer PANI.\u003c/p\u003e\u003cp\u003eC 1s spectra (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eb) exhibited multi-peak fitting characteristics, revealing the complex carbon chemical environment of the material. The main peak at 284.8 eV (C-C/C\u0026thinsp;=\u0026thinsp;C bonds) was attributed to the graphitic framework of the carbon fibers and the conjugated structure of PANI. The secondary peak at 286.16 eV (C-O bonds) originated from oxygen-containing functional groups on the carbon fiber surface or the MXene-C-Ti-O interfacial bonds. The shoulder peak at 287.67 eV (C\u0026thinsp;=\u0026thinsp;O bonds) is likely associated with carboxyl groups on the carbon fiber surface or carbonyl structures at the edges of MXene. Notably, the weak peak at 281.61 eV corresponding to C-Ti bonds provided the first evidence of chemical bonding between MXene, SCNF, and polyaniline (PANI). The formation of such heterointerfacial bonds significantly enhances the structural integrity of the ternary system and provides direct pathways for electron transport.\u003c/p\u003e\u003cp\u003eThe Ti 2p spectrum (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ec) exhibited the typical double-peak structure of MXene, with peaks at 459.13 and 465.01 eV corresponding to the Ti 2p\u003csub\u003e3/2\u003c/sub\u003e and Ti 2p\u003csub\u003e1/2\u003c/sub\u003e signals of Ti-C bonds, respectively, confirming the retention of the layered structure of Ti3C2Tx. Notably, the satellite peaks at 454.97 and 461.01 eV, corresponding to Ti-O bonds, indicated the partial surface oxidation of MXene. In comparison, the Ti-OH bond signal at 456.08 eV indicates hydroxylation modification of the MXene surface. This surface hydroxylation not only improved the wettability of the material but also provided additional adsorption sites for the electrolyte ions.\u003c/p\u003e\u003cp\u003eThe N 1s spectrum (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003ed) showed fitting results with a main peak at 399.74 eV corresponding to -C-N- bonds in PANI, indicating the successful polymerization of aniline monomers into polyaniline. The characteristic peak at 401.83 eV was attributed to PANI's polaronic state of PANI (-N⁺=), confirming the presence of conductive emeraldine salt structures. This oxidation state distribution enabled PANI to contribute pseudo-capacitance via rapid proton doping/de-doping reactions during charge/discharge processes, while its conjugated structure synergistically enhanced the overall conductivity of the material through interaction with the conductive network formed by carbon fibers and MXene\u003c/p\u003e\u003cp\u003eXPS analysis indicated that MXene, SCNF, and PANI formed a good chemical composite in the MXene/SCNF@PANI hybrid nanofiber membrane. The chemical bonding between MXene and SCNF@PANI enhanced the interfacial binding force and the structural stability. The introduction of PANI improves the conductivity and pseudocapacitive performance, whereas the surface hydroxylation of MXene may optimize the wettability and electrochemical performance.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e\u003ch2\u003e4.3 TG Analysis\u003c/h2\u003e\u003cp\u003eTo investigate the thermal stability of the MXene/SCNF@PANI hybrid nanofiber membranes (MSCPM3), TG was performed on MSCPM1, MSCPM2, MSCPM3, and MSCPM4 samples. The TG curve revealed three distinct stages of mass loss during the heating process, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eIn the first stage (0\u0026ndash;150\u0026deg;C), the initial mass loss of the four samples was mainly attributed to the volatilization of adsorbed moisture and residual solvents. The hydrophilic functional groups (such as -OH and -O) on the MXene and SCNF@PANI surfaces facilitated the adsorption of ambient moisture, resulting in significant weight loss at low temperatures. This observation is consistent with the presence of Ti-OH and C-O bonds identified in the XPS analysis, further confirming the hydrophilic nature of the hybrid nanofiber membrane.\u003c/p\u003e\u003cp\u003eIn the second stage (150\u0026ndash;350\u0026deg;C), the quality loss was attributed to the removal of residual impurities, such as Li⁺, F⁻, and Al\u0026sup3;⁺ from the MXene synthesis process, as well as unreacted hydrochloric acid and sodium dodecylbenzene sulfonate from PANI polymerization. These impurities were eliminated within the temperature range of 150\u0026ndash;350\u0026deg;C, contributing to the observed mass reduction. Additionally, the decomposition of unstable surface functional groups (such as hydroxyl and carboxyl groups) on MXene and SCNF may have further contributed to mass loss in this stage.\u003c/p\u003e\u003cp\u003eIn the third stage (350\u0026ndash;600\u0026deg;C), the final stage of mass loss was primarily attributed to the thermal degradation of PANI. Above 350\u0026deg;C, PANI began to deactivate, with its molecular chain structure disintegrating progressively until complete decomposition near 600\u0026deg;C. Despite the thermal degradation of PANI, MSCPM3 retained 86% of its mass, indicating excellent stability at high temperatures. The residual mass (\u0026gt;\u0026thinsp;80%) was primarily attributed to the Ti₃C₂Tₓ matrix, which remained stable up to a critical temperature of over 3000\u0026deg;C. The lower proportion of MXene in MSCPM1 and MSCPM2 resulted in a more significant impact of PANI thermal degradation on the overall mass loss of the composites. In contrast, MSCPM3 and MSCPM4 exhibited better stability owing to their higher MXene content. Among them, MSCPM3 exhibited optimal thermal stability. At a 1:1 mass ratio, good chemical bonds (e.g., C-Ti and Ti-O) were formed between MXene and SCNF@PANI, which significantly enhanced the interfacial bonding and structural integrity of the sample and effectively prevented material decomposition and loss at elevated temperatures. However, the excessively high proportion of MXene in MSCPM4 may have prevented uniform chemical bonding with SCNF@PANI, thereby weakening the overall structural stability and electrochemical performance of the sample.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec19\" class=\"Section2\"\u003e\u003ch2\u003e4.4 Wettability Performance Analysis\u003c/h2\u003e\u003cp\u003eTo investigate the wettability of the MXene/SCNF@PANI composite membranes, dynamic water contact angle measurements were performed on MSCPM1, MSCPM2, MSCPM3, and MSCPM4, with water contact angles recorded over a 0\u0026ndash;7 s interval. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, water droplets were observed to spread completely on the surfaces of MSCPM2 and MSCPM4 within 7 s, with contact angles approaching 0\u0026deg;. In contrast, water droplets achieved complete spreading on the surface of MSCPM3 within only 3 s, resulting in contact angles approaching 0\u0026deg;. Simultaneously, MSCPM2 and MSCPM4 exhibited favorable wettability, and complete droplet spreading required a longer duration (7 s). The occurrence of this phenomenon in MSCPM2 is attributed to the fact that although the MXene and SCNF composite enhances hydrophilicity, the distribution and quantity of surface functional groups are insufficient to achieve rapid wetting. The hydroxyl (-OH) and ether (-O-) functional groups of MXene, combined with the porous structure of SCNF, provide favorable conditions for water molecule spreading; however, the wetting rate remains relatively slow. Due to the hydrophilic properties of MXene, MSCPM4 theoretically exhibits the best wettability. However, an excessively high MXene ratio may lead to insufficiently uniform binding with SCNF@PANI, resulting in a less dense distribution of hydrophilic groups in certain regions, thereby affecting the overall wettability. Although a higher MXene content enhances the mechanical strength and thermal stability of the material to some extent, it may also hinder the rapid transport of electrolyte ions within the porous structure, as excessive MXene nanosheets may stack or cover some pores, limiting the electrolyte penetration pathways. MSCPM1 demonstrated the poorest wetting performance, with a slow droplet spreading speed. The MXene content was the lowest, with a ratio of 1:3 relative to SCNF@PANI, leading to the lowest density of hydrophilic groups and an inability to effectively improve the hydrophilicity of the composite membrane.\u003c/p\u003e\u003cp\u003eIn comparison, the wettability of MSCPM3 was significantly improved, with water droplets spreading completely within 3 seconds. This enhancement was attributed to the presence of polar functional groups (such as -NH- and -N=) on the surface of the conductive polymer PANI, which significantly increased the surface energy of the material and thereby enhanced wettability. The synergistic effect of MXene, SCNF, and PANI further optimized the surface structure of the composite membrane, facilitating stronger interactions with water molecules. The combined contributions of the hydroxyl and ether functional groups of MXene, SCNF\u0026rsquo;s porous structure of SCNF, and PANI\u0026rsquo;s polar functional groups of PANI resulted in a marked improvement in the wettability of the composite membrane.\u003c/p\u003e\u003cp\u003eThis superior wettability implies that the electrolyte can rapidly penetrate the internal structure of the composite membrane, thereby increasing the effective contact area between the electrode material and electrolyte. Such rapid penetration promotes fast ion transport and diffusion, thereby enhancing the electrochemical activity of the electrode materials.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec20\" class=\"Section2\"\u003e\u003ch2\u003e4.5 Electrochemical Performance Analysis\u003c/h2\u003e\u003cdiv id=\"Sec21\" class=\"Section3\"\u003e\u003ch2\u003e4.5.1 Study on the Electrochemical Performance of the Three-Electrode System\u003c/h2\u003e\u003cp\u003eThe CV and EIS measurements were performed using a three-electrode configuration to systematically evaluate the electrochemical performance of MXene/SCNF@PANI hybrid nanofiber membranes. A 1 M H₂SO₄ aqueous solution was employed as the electrolyte, with a potential window set between \u0026minus;\u0026thinsp;0.4 and 0.4 V (vs. Ag/AgCl).\u003c/p\u003e\u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ea, the CV curves of the electrodes at a scan rate of 5 mV s⁻\u0026sup1; exhibited distinct redox peaks (oxidation peak at ~\u0026thinsp;0.2 V and reduction peak at ~-0.1 V), which were attributed to the quinone/benzenoid redox transitions of PANI (Eq.\u0026nbsp;\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e). Notably, the enclosed area of the CV curve for MSCPM3 was the largest, yielding an integrated capacitance value of 1.23 mF cm⁻\u0026sup2;, which was significantly higher than those of MSCPM1 (0.58 mF cm⁻\u0026sup2;), MSCPM2 (0.89 mF cm⁻\u0026sup2;), and MSCPM4 (1.02 mF cm⁻\u0026sup2;). This performance difference directly reflects the optimization degree of the ternary synergistic effect, with the 1:1 MXene: SCNF@PANI ratio in MSCPM3 achieving the highest charge storage capacity.\u003c/p\u003e\u003cp\u003eThe specific capacitance based on the CV data was calculated using Eq.\u0026nbsp;\u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, revealing that MSCPM3 achieved a gravimetric capacitance of 601.8 F g⁻\u0026sup1; at 5 mV s⁻\u0026sup1;, representing a 55.4% improvement over the pristine MXene/SCNF membrane (387.2 F g⁻\u0026sup1;) (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eb). This enhancement was attributed to the pseudocapacitive contribution of PANI (~\u0026thinsp;350 F g⁻\u0026sup1;) combined with the double-layer capacitance of MXene/SCNF. Remarkably, even at a scan rate of 100 mV s⁻\u0026sup1;, MSCPM3 retained a specific capacitance of 425.3 F g⁻\u0026sup1;, demonstrating an excellent rate capability. This can be attributed to the hierarchical porous structure of MSCPM3, which facilitates efficient ion transport and diffusion.\u003c/p\u003e\u003cp\u003eEIS measurements further elucidated the charge-transfer characteristics of the materials. As shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003ec, the equivalent series resistance (Rs) of MSCPM3 was 5.38 Ω, representing a 25.4% reduction compared to that of MSCPM1 (7.21 Ω), while the charge transfer resistance (Rct) decreased by 41.3% to 3.85 Ω. The diameter of the semicircle in the high-frequency region (10⁵ Hz) for MSCPM3 was only 60% of that of MSCPM1, indicating more efficient interfacial charge transfer. In the low-frequency region (0.01 Hz), the Warburg impedance slope (Z' vs. ω⁻\u0026sup1;/\u0026sup2;) of MSCPM3 was 1.23 Ω s⁻\u0026sup1;/\u0026sup2;, which was significantly lower than that of MSCPM1 (1.85 Ω s⁻\u0026sup1;/\u0026sup2;), corresponding to a higher ionic diffusion coefficient (D\u0026thinsp;=\u0026thinsp;1.58\u0026times;10⁻\u003csup\u003e10\u003c/sup\u003e cm\u0026sup2; s⁻\u0026sup1;). This multiscale synergistic mechanism provides a kinetic foundation for the superior electrochemical performance of MSCPM3.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec22\" class=\"Section3\"\u003e\u003ch2\u003e4.5.2 Study on the Electrochemical Performance of a Two-Electrode System\u003c/h2\u003e\u003cp\u003eTo further evaluate the practical performance of the MXene/SCNF@PANI hybrid nanofiber membranes, symmetric supercapacitors were assembled using two MSCPM3 electrodes of identical dimensions and tested in a two-electrode configuration with 1 mol/L H₂SO₄ as the electrolyte. GCD and cyclic stability tests were performed to assess the electrochemical behavior of the cells.\u003c/p\u003e\u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003ea presents the GCD curves of MSCPM3 electrodes at various current densities (1 A g⁻\u0026sup1; to 5 A g ⁻\u003csup\u003e1\u003c/sup\u003e). The curves exhibited quasi-triangular profiles without significant voltage drops, indicating excellent capacitive behavior and rapid charge storage kinetics. However, slight deviations from the ideal triangular shapes were observed, which were primarily attributed to the pseudocapacitive contributions of PANI. During the charge-discharge cycles, redox reactions in PANI introduced additional pseudo-capacitance alongside double-layer capacitance, leading to the observed deviations. This pseudocapacitive behavior further enhances the electrochemical performance of the hybrid nanofiber membrane.\u003c/p\u003e\u003cp\u003eFigure\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003eb illustrates the cyclic stability of the MSCPM3-based supercapacitors tested at 1 A g⁻\u0026sup1;. After 10,000 charge-discharge cycles, the device retained 81.5% of its initial capacitance, demonstrating remarkable cycling stability. This stability was attributed to the chemical bonding between MXene and SCNF@PANI, which reinforced the structural integrity of the hybrid nanofiber membrane and prevented the degradation or failure of the electrode material during cycling. Additionally, the optimized interfacial properties of the composite reduced the interfacial resistance and polarization, further enhancing durability.\u003c/p\u003e\u003cp\u003eThe superior performance of MSCPM3 in GCD and cyclic stability tests underscores the practical potential of MXene/SCNF@PANI hybrid nanofiber membranes in supercapacitor applications.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"5. Conclusions","content":"\u003cp\u003eThis study synthesized a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid nanofiber membrane (MSCPM3) via chemical oxidative polymerization and vacuum-assisted filtration, integrating MXene, short carbon nanofibers (SCNF), and polyaniline (PANI). With an optimized MXene:SCNF@PANI mass ratio of 1:1, MSCPM3 formed a uniform 3D porous structure with homogeneous C, N, Ti distribution, and C-Ti/Ti-O covalent bonds between components. It achieved a record specific capacitance of 601.8 F g⁻\u0026sup1; at 5 mV s⁻\u0026sup1; (surpassing most MXene-based hybrids), low equivalent series resistance (5.38 Ω) and charge transfer resistance (3.85 Ω), rapid water spreading (3 s, contact angle\u0026thinsp;\u0026asymp;\u0026thinsp;0\u0026deg;), and 81.5% capacitance retention after 10,000 cycles. The high performance of MSCPM3 stems from multi-scale synergy: SCNF\u0026rsquo;s porous 1D framework suppresses MXene restacking and enhances mechanical stability; MXene\u0026rsquo;s 2D conductive network (10⁴\u0026ndash;10⁵ S cm⁻\u0026sup1;) compensates for PANI\u0026rsquo;s low conductivity (10⁻\u0026sup3;\u0026ndash;100 S cm⁻\u0026sup1;); PANI\u0026rsquo;s redox-active sites provide pseudo-capacitance (300\u0026ndash;500 F g⁻\u0026sup1;) to complement MXene/CNF\u0026rsquo;s EDLC. XPS-verified C-Ti/Ti-O bonds reduce interfacial resistance and prevent component detachment, while synergistic hydrophilic groups (-OH in MXene, -NH-/-N\u0026thinsp;=\u0026thinsp;in PANI) and SCNF porosity accelerate electrolyte infiltration. This work provides a scalable strategy for high-performance supercapacitor electrodes, advancing MXene integration with carbon nanomaterials and conductive polymers. Future research should optimize membrane thickness and explore scalability for flexible/high-temperature devices.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAuthor Contributions\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eZhengyu Ding\u003c/strong\u003e: Conceptualization, Methodology, Formal analysis, Investigation, Resources, Data curation, Writing original draft, Visualization.\u003cstrong\u003e\u0026nbsp;Maoyu You\u003c/strong\u003e: Data curation, Writing original draft, Methodology, Writing review \u0026amp; editing.\u0026nbsp;\u003cstrong\u003eBinjie Xin\u003c/strong\u003e: Validation, Writing review \u0026amp; editing, Supervision, Project administration. \u003cstrong\u003eMd All Amin Newton:\u0026nbsp;\u003c/strong\u003eWriting review \u0026amp; editing. All authors reviewed the manuscript.\u003c/p\u003e\n\u003cp\u003eAcknowledgments\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Project of Local University Ability Building of Shanghai Scientific and Technological Committee (19030501200).\u003c/p\u003e\n\u003cp\u003eConflicts of interest\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.\u003c/p\u003e\n\u003cp\u003eData availability\u003c/p\u003e\n\u003cp\u003eData will be made available on request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eLi X, Huang Z, Shuck CE, et al (2022) MXene chemistry, electrochemistry and energy storage applications. Nature Reviews Chemistry 6:389\u0026ndash;404. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41570-022-00384-8\u003c/span\u003e\u003cspan address=\"10.1038/s41570-022-00384-8\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGao M, Wang F, Yang S, et al (2023) Engineered 2D MXene-based materials for advanced supercapacitors and micro-supercapacitors. Materials Today. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mattod.2023.12.009\u003c/span\u003e\u003cspan address=\"10.1016/j.mattod.2023.12.009\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYuan T, Zhang Z, Liu Q, et al (2023) MXene (Ti3C2Tx)/cellulose nanofiber/polyaniline film as a highly conductive and flexible electrode material for supercapacitors. Carbohydrate Polymers 304:120519. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.carbpol.2022.120519\u003c/span\u003e\u003cspan address=\"10.1016/j.carbpol.2022.120519\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eAhmad F, Shahzad A, Danish M, et al (2024) Recent developments in transition metal oxide-based electrode composites for supercapacitor applications. Journal of Energy Storage 81:110430. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.est.2024.110430\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2024.110430\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShin S-J, Gittins JW, Balhatchet CJ, et al (2023) Metal\u0026ndash;Organic Framework Supercapacitors: Challenges and Opportunities. Advanced Functional Materials 34:. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/adfm.202308497\u003c/span\u003e\u003cspan address=\"10.1002/adfm.202308497\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHu A, Li F, Chen W, et al (2022) Ion Transport Kinetics in Low-Temperature Lithium Metal Batteries. Advanced Energy Materials 12:. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/aenm.202202432\u003c/span\u003e\u003cspan address=\"10.1002/aenm.202202432\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZheng J, Wang J, Qu J, et al (2022) CeO2/Ni-Al layered double hydroxide composite electrode for the enhancement of specific capacitance and capacitance retention performance. Applied Clay Science 216:106370. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.clay.2021.106370\u003c/span\u003e\u003cspan address=\"10.1016/j.clay.2021.106370\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJoseph A, Mathew A, Perikkathra S, Thomas T (2024) Recent advances in and perspectives on binder materials for supercapacitors\u0026ndash;A review. European Polymer Journal 210:112941. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.eurpolymj.2024.112941\u003c/span\u003e\u003cspan address=\"10.1016/j.eurpolymj.2024.112941\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLevitt AS, Alhabeb M, Hatter CB, et al (2019) Electrospun MXene/carbon nanofibers as supercapacitor electrodes\u0026dagger;. Journal of Materials Chemistry A 7:269\u0026ndash;277. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1039/c8ta09810g\u003c/span\u003e\u003cspan address=\"10.1039/c8ta09810g\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi L, Lu F, Xue R, et al (2019) Ultrastable Triazine-Based Covalent Organic Framework with an Interlayer Hydrogen Bonding for Supercapacitor Applications. ACS Appl Mater Interfaces 11:26355\u0026ndash;26363. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acsami.9b06867\u003c/span\u003e\u003cspan address=\"10.1021/acsami.9b06867\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eGupta S, Thacharakkal D, Subramaniam C, Ramakrishnan S (2024) Nanocarbon Florets with Synthetically Tunable Porosity as High-Rate Anodes for Li-ion Batteries. ACS Applied Nano Materials 7:27336\u0026ndash;27343. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acsanm.4c05368\u003c/span\u003e\u003cspan address=\"10.1021/acsanm.4c05368\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eIsacfranklin M, Yuvakkumar R, Ravi G, et al (2023) SmNiO3/SWCNT perovskite composite for hybrid supercapacitor. Journal of Energy Storage 68:107786. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.est.2023.107786\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2023.107786\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eKomatsubara K, Suzuki H, Inoue H, et al (2022) Highly Oriented Carbon Nanotube Supercapacitors. ACS Applied Nano Materials. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/acsanm.1c04236\u003c/span\u003e\u003cspan address=\"10.1021/acsanm.1c04236\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhai S, Chen Y (2022) Graphene-Based Fiber Supercapacitors. Accounts of Materials Research 3:922\u0026ndash;934. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1021/accountsmr.2c00087\u003c/span\u003e\u003cspan address=\"10.1021/accountsmr.2c00087\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePan Z, Cui B, Gong X, et al (2025) Zinc ion coordination doped polyaniline electrode for high performance supercapacitors. Journal of Energy Storage 120:116431. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.est.2025.116431\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2025.116431\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eTang D, Zhitomirsky I (2025) Synergy of Pseudocapacitive Properties of Ferromagnetic La1\u0026thinsp;\u0026ndash;\u0026thinsp;xSrxMnO3 and Polypyrrole in high Active Mass Composite Electrodes for Supercapacitors. Journal of Inorganic and Organometallic Polymers and Materials. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s10904-025-03610-0\u003c/span\u003e\u003cspan address=\"10.1007/s10904-025-03610-0\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYan W, Yan S, Cai D, et al (2025) Synthesis of MXene films with horizontally and vertically hierarchical pores for high-performance supercapacitors. Electrochimica Acta 146479. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.electacta.2025.146479\u003c/span\u003e\u003cspan address=\"10.1016/j.electacta.2025.146479\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eJiang H, Yuan B, Guo H, et al (2024) Malleable, printable, bondable, and highly conductive MXene/liquid metal plasticine with improved wettability. Nature Communications 15:. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1038/s41467-024-50541-4\u003c/span\u003e\u003cspan address=\"10.1038/s41467-024-50541-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLyu S, Chang H, Zhang L, et al (2023) High specific surface area MXene/SWCNT/cellulose nanofiber aerogel film as an electrode for flexible supercapacitors. Composites Part B: Engineering 264:110888. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.compositesb.2023.110888\u003c/span\u003e\u003cspan address=\"10.1016/j.compositesb.2023.110888\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eShi M, Wang R, He J, et al (2022) Multiple Redox-active Cyano-substituted Organic Compound Integrated with MXene for High-Performance Flexible Aqueous K-ion Battery. Chemical Engineering Journal 450:138238. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.cej.2022.138238\u003c/span\u003e\u003cspan address=\"10.1016/j.cej.2022.138238\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDing L, Wei Y, Wang Y, et al (2017) A Two-Dimensional Lamellar Membrane: MXene Nanosheet Stacks. Angewandte Chemie International Edition 56:1825\u0026ndash;1829. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/anie.201609306\u003c/span\u003e\u003cspan address=\"10.1002/anie.201609306\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003ePeng Y, Zhang X, Sun R, et al (2024) Review of electro-spun carbon nanofiber electrode materials for electrochemical capacitors. Journal of Materials Chemistry A 12:32566\u0026ndash;32592. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1039/d4ta06221c\u003c/span\u003e\u003cspan address=\"10.1039/d4ta06221c\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYan S, Jin S, He X, et al (2025) Direct synthesis of composite conductive carbon nanofiber aerogels with continuous internal networks for collaborative physiological signal monitoring under complex environments. Sensors and Actuators B: Chemical 426:136975. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.snb.2024.136975\u003c/span\u003e\u003cspan address=\"10.1016/j.snb.2024.136975\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen Y, Tu C, Liu Y, et al (2022) Microstructure and mechanical properties of carbon graphite composites reinforced by carbon nanofibers. Carbon Letters 33:561\u0026ndash;571. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s42823-022-00445-4\u003c/span\u003e\u003cspan address=\"10.1007/s42823-022-00445-4\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYou M, Xin B (2024) MXene Nanosheets and Carbon Nanofiber Hybrid Membranes for Electrochemical Energy Storage Materials. Fibers Polym 25:3323\u0026ndash;3330. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s12221-024-00679-1\u003c/span\u003e\u003cspan address=\"10.1007/s12221-024-00679-1\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eSchmidt A, Husmann S, Presser V, Zarbin AJG (2025) Transparent polyaniline/MXene thin films supercapacitors. Electrochimica Acta 146184. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.electacta.2025.146184\u003c/span\u003e\u003cspan address=\"10.1016/j.electacta.2025.146184\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChu J, Li X, Li Q, et al (2019) Hydrothermal synthesis of PANI nanowires for high-performance supercapacitor. High Performance Polymers 32:258\u0026ndash;267. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1177/0954008319856664\u003c/span\u003e\u003cspan address=\"10.1177/0954008319856664\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eHwang H, Byun S, Yuk S, et al (2021) High-rate electrospun Ti3C2Tx MXene/carbon nanofiber electrodes for flexible supercapacitors. Applied Surface Science 556:149710. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.apsusc.2021.149710\u003c/span\u003e\u003cspan address=\"10.1016/j.apsusc.2021.149710\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eChen T, Li M, Li Y, et al (2023) Synthesis of hierarchical structure MXene/PANI composite hybrid electrodes for supercapacitors. Materials Science and Engineering: B 290:116354. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.mseb.2023.116354\u003c/span\u003e\u003cspan address=\"10.1016/j.mseb.2023.116354\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eZhou X, Wang S, Ma G, et al (2024) Aniline-co-pyrrole (ANPY)/MXene composites with high specific capacitance for flexible supercapacitors. Journal of Energy Storage 97:112951. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.est.2024.112951\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2024.112951\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eDonthula K, Malothu UR, Araga R, et al (2023) Flexible polyaniline/MXene/CNF composite nanofibrous mats as high-performance supercapacitor electrodes. Polymer Composites 44:7571\u0026ndash;7584. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1002/pc.27646\u003c/span\u003e\u003cspan address=\"10.1002/pc.27646\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eYang J, Yang Y, Lan J, et al (2019) Polyaniline-manganese dioxide-carbon nanofiber ternary composites with enhanced electrochemical performance for supercapacitors. Journal of Electroanalytical Chemistry 843:22\u0026ndash;30. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jelechem.2019.04.073\u003c/span\u003e\u003cspan address=\"10.1016/j.jelechem.2019.04.073\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eFazal A, Zafar MM, Iqbal MJ, et al (2025) High-performance supercapacitor electrode synthesized by in-situ chemical oxidative polymerization of TiO2/PANI composite. Synthetic Metals 311:117842. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.synthmet.2025.117842\u003c/span\u003e\u003cspan address=\"10.1016/j.synthmet.2025.117842\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eWang J, He J, Kan D, et al (2022) MXene Film Prepared by Vacuum-Assisted Filtration: Properties and Applications. Crystals 12:1034. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.3390/cryst12081034\u003c/span\u003e\u003cspan address=\"10.3390/cryst12081034\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e\u003cli\u003e\u003cspan\u003eLi W, Farhadi B, Liu M, et al (2025) Interface engineering based NiCoMoO4/Ti3C2Tx MXene heterostructure for high-performance flexible supercapacitors. Journal of Colloid and Interface Science 677:541\u0026ndash;550. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1016/j.jcis.2024.08.093\u003c/span\u003e\u003cspan address=\"10.1016/j.jcis.2024.08.093\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\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":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Supercapacitor, MXene, Carbon Nanofibers, Polyaniline, Synergy","lastPublishedDoi":"10.21203/rs.3.rs-7440091/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7440091/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eFlexible supercapacitors require electrode materials that integrate high specific capacitance, mechanical robustness, and efficient ionic transport. Herein, a novel MXene/short carbon nanofiber@polyaniline (MSCPM) hybrid membrane was synthesized via chemical oxidative polymerization and vacuum-assisted filtration. By optimizing the mass ratio of MXene to short carbon nanofiber@polyaniline (SCNF@PANI), a three-dimensional hierarchical architecture was achieved, where MXene nanosheets interlocked with PANI-coated CNFs to form covalent interface bonds. This design leverages the metallic conductivity of MXenes for rapid electron transport, CNFs' mechanical rigidity of CNFs to maintain structural integrity, and PANI's pseudo-capacitance of PANI for enhanced energy storage. The hybrid membrane exhibited exceptional electrochemical performance, achieving a specific capacitance of 601.8 F g\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at 5 mV s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, surpassing most reported MXene-based materials. Notably, the composite retained 81.5% of its capacitance after 10,000 cycles, demonstrating remarkable cycling stability. The synergistic integration of hydrophilic MXenes, porous CNFs, and polar PANI functionalities ensures efficient electrolyte infiltration and ion diffusion. Simultaneously, the covalent interface bonds enhance the charge transfer efficiency and structural integrity. This work establishes a scalable strategy for high-performance supercapacitor electrodes, advancing the integration of MXenes with carbon nanomaterials and conductive polymers. These design principles provide new insights into interfacial engineering for multifunctional energy storage applications, particularly in flexible and high-temperature devices.\u003c/p\u003e","manuscriptTitle":"Architecting Triple Synergy: MXene-Enhanced Short Carbon Nanofibers Interlaced with Polyaniline for Supercapacitors","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-04 15:03:04","doi":"10.21203/rs.3.rs-7440091/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-09-09T14:26:30+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-07T14:34:12+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-07T11:06:24+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-03T08:45:18+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-09-02T12:57:19+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"272894820390814375123733970136927929533","date":"2025-08-31T14:25:54+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-08-31T00:33:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"158808565016382183811193833509750013718","date":"2025-08-29T01:54:48+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"53132270626106069332480956779481418286","date":"2025-08-28T23:35:32+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"78648308995647604598185455319294656837","date":"2025-08-28T13:40:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"9881146830568303670943750268196786514","date":"2025-08-28T11:59:11+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-08-28T11:34:09+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-08-27T23:43:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-08-27T23:43:12+00:00","index":"","fulltext":""},{"type":"submitted","content":"Ionics","date":"2025-08-23T09:05:52+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"ionics","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"","sideBox":" Learn more about [Ionics](https://www.springer.com/journal/11581) ","snPcode":"11581","submissionUrl":"https://mc.manuscriptcentral.com/ionics","title":"Ionics","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"7fa622fa-1ea4-440e-8289-9b6d2f5741c2","owner":[],"postedDate":"September 4th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2025-11-05T23:53:12+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-04 15:03:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7440091","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7440091","identity":"rs-7440091","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}