Carbon Black-Modified Polyvinyl Alcohol-Based Gel Polymer Electrolytes with Enhanced Ionic Conductivity

Carbon Black-Modified Polyvinyl Alcohol-Based Gel Polymer Electrolytes with Enhanced Ionic Conductivity | 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 Carbon Black-Modified Polyvinyl Alcohol-Based Gel Polymer Electrolytes with Enhanced Ionic Conductivity A. A. Rahim, C. G. Er, P. Q. B. Mazlan, A. R. M. Rais, N. M. Disa, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8952004/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 A safer and more stable gel polymer electrolytes (GPEs) have gained attention as potential alternatives to liquid electrolytes in electrochemical systems. However, their performance is limited by their high polymer crystallinity and low ionic conductivity. In this study, a series of polyvinyl alcohol (PVA)-based GPEs system were synthesized using potassium iodide (KI) salt in ethylene carbonate (EC), propylene carbonate (PC), and dimethyl sulfoxide (DMSO) solvent. Various concentrations of carbon black (CB) nanofillers were added in electrolytes to study the effect of nanofiller on electrolyte characteristics. The structural and electrochemical properties of the GPEs was systematically investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS). XRD results confirmed a reduction in crystallinity with increasing CB content, while FTIR analysis indicated strong interactions between CB and the polymer matrix. A notable enhancement in ionic conductivity achieved a maximum value of 11.80 mS cm − 1 with addition of 12 wt.% of CB, indicating improved ion transport pathways. The findings demonstrate that carbon black plays a critical role in tailoring the physical and electrochemical characteristics of PVA-based GPEs, offering promising potential for advanced electrochemical applications. Gel polymer electrolyte Polyvinyl alcohol Carbon black Ionic conductivity Electrochemical properties Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 1. Introduction The growing demand for environmentally friendly and efficient energy conversion systems has increased the interest of researchers to continuously explore innovative materials and technologies to enhance electrochemical device performance. Electrochemical devices like dye-sensitized solar cells, lithium-ion batteries, and supercapacitors utilize electrolytes to transport ions between electrodes, which is crucial for energy conversion and storage. Liquid electrolytes with high ionic conductivity (~ 10 − 3 − 10 − 2 S cm − 1 ) are widely employed in these devices [ 1 , 2 ]. However, these traditional liquid electrolytes have issues relating to leakage and flammability [ 2 – 4 ]. Gel polymer electrolytes (GPEs) have drawn interest as alternatives to liquid electrolytes as they offer enhanced safety, mechanical integrity, and flexibility [ 3 – 5 ]. It has been reported that the ionic conductivity of GPEs have achieved in the range of 10 − 4 − 10 − 3 S cm − 1 [ 4 , 5 ]. Some of polymers that has been reported in synthesis of GPE are polyvinyl alcohol (PVA), polyethylene glycol (PEO), polymethyl methacrylate (PMMA), and polyacrylonitrile (PAN) [ 5 – 7 ]. PVA is a semicrystalline and hydrophilic, which often used as a host polymer in GPE preparation due to its excellent chemical stability, nontoxicity and biodegradability [ 7 , 8 ]. However, the high crystallinity due to the semi-crystalline nature of polymers, limits ionic mobility, leading to low ionic conductivity. These requiring modifications to provide better performance of GPEs. Thus, to improve the performance of GPEs, various studies and methods have been explored including addition of salts, plasticizers or additives, and nanofillers. Dopant salt in polymer electrolytes provide additional charge carriers which help to enhance electrical stability and ionic conductivity in a variety of solvents. Salt selection for the preparation of GPEs is essential for optimal electrochemical applications, with low lattice energy being significant for improved salt dissociation and ion transport. Previous studies have been used iodide salts in preparation of GPEs especially in dye-sensitized solar cell (DSSC) application like potassium iodide (KI), lithium iodide (LiI), and sodium iodide (NaI) [ 9 – 11 ]. KI is one of the most common salts used as it has lower lattice energy of 627 kJ mol − 1 and small cations which helps in ion dissociation [ 11 , 12 ]. Recent studies have focused on incorporation of nanofillers to improve the performance of GPEs since they can reduce the crystallinity in polymer matrix. Carbon black (CB) is among of the nanofillers, is a conductive carbon-based nanomaterial which offers multiple advantages. CB has a large surface area, excellent chemical stability, and has the potential to improve both structural and electrochemical properties of polymer matrices [ 13 ]. Despite its wide usage in batteries and capacitors, its application in PVA-based GPEs remains underexplored. This study aims to investigate the effects of CB loading on the structural, spectroscopic, and ionic conductivity properties of PVA-based GPEs with KI as dopant salt. The results provide new insights into the role of carbon-based nanofillers in tailoring polymer electrolyte performance for electrochemical applications. 2. Methodology 2.1 Materials Dimethyl sulfoxide (DMSO) was obtained from R&M Chemicals. Polyvinyl alcohol (PVA) (99% hydrolysed), ethylene carbonate (EC), propylene carbonate (PC), and carbon black (CB), and iodine (I 2 ) crystals were purchased from Sigma Aldrich. Potassium iodide (KI) was obtained from Univar Analytical Reagent. 2.2 Preparation of Gel Polymer Electrolyte (GPE) Gel polymer electrolyte (GPE) was synthesized by employed a solution-casting technique. A high-purity polyvinyl alcohol (PVA) was employed as the host polymer, potassium iodide (KI) as dopant salt, and carbon black (CB) as the nanofiller. Dimethyl sulfoxide (DMSO) was used as the solvent, while ethylene carbonate (EC) and propylene carbonate (PC) acted as plasticizers to enhance ionic mobility. Initially, 0.42 g of KI salt was dissolved in 2 ml of DMSO with EC \(\left(0.3g\right)\) and PC \(\left(0.33ml\right)\) at 30°C for 15 minutes. Separately, 0.2 g PVA was dissolved in 2 ml of DMSO at \(75℃\) under agitation at 420 rpm for 20 minutes. Both solutions were combined and stirred continuously at 80°C for 30 minutes, followed by sequential addition of CB at varied concentration until complete dissolution. The resulting samples, labelled as CB1-CB7, contained 0, 3, 6, 9, 12, 15, and 18 wt.% carbon black, respectively. Lastly, iodine (I 2 ) crystals were added at \(45℃\) for 10 minutes. The amount of I 2 added was 10% molar ratio of the total iodide ions in salt. The final mixture of GPE samples were transferred into veils and cured in a desiccator to prevent contamination and ensure uniformity. The designation and composition of GPE samples were listed in Table 1 . Table 1 Designation and composition of PVA-KI-EC-PC-CB GPE system with fixed amount of PVA (0.2 g), KI (0.294 g), EC (0.3 g), PC (0.4 g), and DMSO (2 ml), and I 2 (0.646 g). Designation CB \((\text{w}\text{t}.\text{%})\) CB (g) CB1 0 0.0000 CB2 3 0.2388 CB3 6 0.5015 CB4 9 0.6515 CB5 12 0.8815 CB6 15 1.0887 CB7 18 1.2903 2.3 Fourier transform infrared spectroscopy (FTIR) The FTIR spectra were recorded on FTIR spectrophotometer (iS10, Thermo Scientific) with an attenuated total reflectance (ATR) attachment, allowing for direct analysis without additional sample treatment [ 14 ]. Measurements were carried out in the 500–4000 cm –1 range with a spectral resolution of 2 cm –1 . FTIR spectra were referenced with those of pure samples (PVA, KI, EC, PC, and CB), looking for shifts in peaks, differences in intensity, and new absorption bands, especially with respect to the \(O-H\) stretch (~ 3300 cm –1 ), \(C=O\) stretch (~ 1700 cm –1 ), \(C-O-C\) stretch (~ 1100 cm –1 ), and iodide-associated vibrations between 500–800 cm –1 for easier identification of specific chemical interactions [ 15 , 16 ]. The spectroscopic alteration noticed was utilized to infer potential interactions among plasticizers, polymer, salt, and nanofiller. The incorporation of carbon black was also specifically investigated for its influence on the network of hydrogen bonding of PVA and its impacts on subsequent ionic conductivity. Such findings confirmed the development of the PVA-based GPE system and provided insight into the structural role played by carbon black as a nanofiller in enhancing the polymer matrix. 2.4 X-ray diffraction (XRD) The XRD analysis was carried out on a PANalytical X'Pert PRO MRD PW3040 diffractometer with Cu-Kα radiation ( \(\lambda=0.154nm\) ) at 40 kV and 30 mA. Diffraction patterns were registered in the 2θ range between \(5^\circ-55^\circ\) with a scan rate of \(2^\circmin⁻¹\) and a count time of 1s per step, which was the optimal compromise between data quality and efficiency. The obtained diffraction spectra were analysed to determine the degree of crystallinity according to the peak sharpness and intensity, where sharp and narrow peaks indicated crystalline domains and broad peaks corresponded to amorphous regions. The crystallite size ( D ) was estimated using the Debye-Scherrer equation [ 17 ]: $$D=\frac{K\lambda}{\beta\text{cos}\theta}$$ (1) where K is the Scherrer constant (0.98), λ is the X-ray wavelength (0.154 nm), and β is the full width at half maximum (FWHM). Further analysis was dedicated to identifying the characteristic diffraction peaks of PVA, CB, KI, and I 2 and assessing the structural changes induced by CB addition as a nanofiller. 2.5 Electrochemical impedance spectroscopy (EIS) Measurement Electrochemical impedance spectroscopy (EIS) was conducted using an electrochemical workstation, which is HIOKI 3532-50 LCR HiTester in the frequency range of 50 Hz to 100 kHz at room temperature (25°C). This experiment was designed to study the ionic conductivity and charge transfer behaviour of the PVA-based GPE. The gel electrolyte membrane was sandwiched between two stainless steel electrodes, and the setup was sealed to minimize the interference of external humidity to accurately measure bulk resistance and ionic conductivity. An AC voltage of 10 mV was applied to maintain the system behaviour pseudo-linear for the response to obey Ohm's law and to be modelled with certainty. The resultant impedance spectra were plotted in the form of Nyquist plots, and the bulk resistance ( \({R}_{b}\) ) was identified from the intercept of the real axis at high frequency. The ionic conductivity ( \(\sigma\) ) was then calculated using the relation [ 18 ]: $$\sigma=\frac{t}{{R}_{b}A}$$ (2) where \(t\) is the electrolyte thickness \(\left(0.2cm\right)\) , \({R}_{b}\) is the bulk resistance, and \(A\) is the stainless-steel electrode contact area \(\left(2.010619{cm}^{2}\right)\) . The influence of CB as a nanofiller was investigated through monitoring \({R}_{b}\) variation and the corresponding variation in ionic conductivity. 3. Results and Discussion 3.1 X-ray diffraction (XRD) Analysis Figure 1 illustrates the XRD patterns of GPEs containing CB at different concentrations (CB1-CB7). The pristine carbon black exhibited an unmistakable crystalline peak at 2θ ≈ 26.39°, which fell within the typical 25–30° range, confirming its natural crystallinity. This peak was utilized as a reference point to evaluate changes in the structure of modified GPE samples. From CB1 to CB4, there was a stepwise decrease in crystallite size, where CB4 exhibited the highest full width at half maximum (FWHM) of 0.12 rad as listed in Table 2 . The broad peak and small crystallite size of CB4 indicate higher structural disorder as well as higher amorphous content. Thus, these improve the ionic conductivity of GPE by reducing crystallinity and providing flexible pathways for ion transport within the polymer matrix. The same trends have been reported by Noer et al. [ 19 ] that synthesized a low-density polyethylene (LDPE)-CB nanocomposites, where lower loadings of CB at 5 wt.% consist of more dispersed fillers and greater loadings consist of distinct agglomeration .Ungár et al. [ 20 ] also explained that the widening of the peak in CB is caused by extremely small crystallites, lattice strain, and uneven particle shape, which inhibit ordered stacking. Hence, CB1-CB4 signify that more carbon black content disturbs the crystalline packing in the polymer matrix and prefers amorphous forms. In contrast, CB5-CB7 revealed narrower peaks with small shifts towards higher 2θ values. Peak locations were recorded at 26.45° (CB5), 26.08° (CB6), and 26.39° (CB7), while crystallite size was increased to 10.05 nm for CB7 and FWHM correspondingly, indicating higher crystallinity. This improvement is attributed to compositional effects for improved graphitic stacking, thermal treatment, or catalytic effects. Zhang et al. [ 21 ] reported that ball-milling of CB can induce more ordered graphitic domains, as observed in higher peak intensity, 2θ shift towards higher values, and less amorphous carbon content. Consistently, originally low-crystallinity CB in the current study revealed a broad shoulder between 15° and 23.7° due to amorphous carbon, whereas CB5-CB7 exhibited structural reordering. Table 2 The XRD peak position and FWHM. Sample \(2\theta\left(^\circ\right)\) FWHM (rad) Pure carbon black 26.39 0.02 CB1 21.12 0.03 CB2 20.98 0.04 CB3 25.27 0.06 CB4 24.59 0.12 CB5 26.45 0.02 CB6 26.08 0.02 CB7 26.39 0.01 Moreover, at CB5-CB7 also where it being observed that crystallinity increase is due to agglomeration. CB aggregation limits the uniform ion distribution which lead to low ionic conductivity. The increase in the concentration of CB could lead to hydrophobicity and causing incompatibility with the polymer matrix, which could enhance surface energy and cause partial structural reordering [ 22 ]. This phenomenon corresponds to the increased graphitic stacking in CB5-CB7. The trends are also consistent with the Scherrer equation in which FWHM is inversely related to crystallite size. Overall, XRD information indicates that CB4 is the most amorphous among all samples, whereas CB5-CB7 are more crystalline than pure carbon black, suggesting that they are suitable for applications requiring well-ordered carbon structures. 3.2 FTIR analysis Figure 2 shows the FTIR spectra of the PVA-EC-PC-KI-CB system, highlighting key vibrational changes that reflect molecular interactions among the components. The C = O stretching region (~ 1770–1777 cm⁻¹) shows slight shifts from CB1 to CB7, indicating coordination between the carbonate groups (EC & PC) and K⁺ ions, as well as possible interactions with CB surfaces. The C = C stretching (~ 1650 cm⁻¹) in carbon black suggests weak π-π interactions or hydrogen bonding with the polymer matrix, while the broad O-H stretching band (~ 3300–3400 cm⁻¹) confirms strong hydrogen bonding among PVA, KI, and CB. C-H stretching (3000 − 2850 cm⁻ 1 ) reflects contributions from PVA, EC, and PC, influenced by hydrogen bonding, ion-dipole interactions, and plasticization effects. Shifts in the C-O (1004–1014 cm⁻ 1 ) and O-H bending (1404–1438 cm⁻ 1 ) regions further indicate dynamic polymer-filler and polymer-ion interactions. The C = C bending vibrations (945–952 cm⁻ 1 ) demonstrate π–π stacking and electronic coupling between CB and the polymer matrix, enhancing filler dispersion and interfacial interactions. The summary of the FTIR peaks for PVA-EC-PC-KI-CB system is shown in Table 3 . Thus, all the spectral shifts highlighted that the hydrogen bonding, ion-dipole interactions and van der Waals forces all play crucial roles in the complex system of GPE. Increasing CB content will affect the balance between mechanical strength and ionic transport, providing insight into optimizing the performance of the GPE [ 23 – 25 ]. Figure 3 illustrates the interaction in the polymer-salt-nanofiller system. Table 3 FTIR wavenumber assignments for PVA-EC-PC-KI-CB system at varying CB concentrations. Wavenumber (cm − 1 ) Reference Assignments PVA-EC-PC-KI-CB CB1 CB2 CB3 CB4 CB5 CB6 CB7 O-H Stretching 3326 3300 3294 3276 3361 3334 3301 [ 23 , 26 ] C-H Stretching 2936 2924 2924 2931 2923 2924 2931 [ 23 , 26 ] C = O Stretching 1777 1771 1775 1775 1775 1774 1776 [ 23 , 26 ] C = C Stretching 1653 1651 1647 1653 1653 1647 1653 [ 27 , 28 ] O-H Bending 1421 1438 1405 1404 1405 1405 1409 [ 29 – 31 ] C-O Stretching 1010 1008 1009 1014 1014 1004 1012 [ 32 , 33 ] C = C Bending 950 949 945 948 951 951 952 [ 24 – 26 ] 3.3 Electrochemical impedance spectroscopy (EIS) analysis The bulk resistance, \({R}_{b}\) was derived from the Nyquist plots as shown in Fig. 4 below. The impedance spectra of all GPE samples, CB1 to CB7, comprised a single inclined spike line in the low-frequency region, without any discernible semicircle in the high-frequency range. This is a feature of gel polymer electrolytes, where charge transport is regulated by ionic conduction with minimal contribution from electronic pathways and insignificant charge-transfer resistance [ 34 ]. The absence of a semicircle signifies high ionic mobility and minimal interfacial impedance consistent with the overall conductivity of the systems [ 34 , 35 ]. It can be observed that R b increased upon incorporation of 3 wt.% (CB2) due to poor CB dispersion, disrupting the amorphous PVA ion conduction pathways. As CB content reached 12 wt.% (CB5), R b decreased owing to efficient formation of conductive pathways that enhance ion transport [ 37 ]. Further addition to 15 wt.% (CB6) through 18 wt.% (CB7) increased R b again, resulting CB aggregation and hinders ion pathways [ 38 ]. Likewise, the ionic conductivity results, as shown in Fig. 5 , show that CB1 which is GPE sample without the carbon black possesses the highest conductance of \((1.59\pm0.13)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) . This is a result of the highly amorphous nature of the PVA-EC-PC-KI matrix that supports efficient dissociation of salts and mobility of ions. The initial carbon black addition at 3 wt.% (CB2) led to the significant decrease in conductivity to \((0.12\pm0.02)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) , as the agglomeration probably upsets the polymer-ion network. An increase in adding carbon black to 6 wt.% (CB3) led to an increase in conductivity to \((0.96\pm0.06)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) , indicating that a low level of filler can enhance the amorphous phase and ion mobility. At 9 wt.% (CB4), conductivity slightly decreased to ( \(0.75\pm0.01)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) , whereas increasing further to yield the highest conductivity at 12 wt.% of CB5, \((1.18\pm0.00)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) . This suggests that the optimal filler content promotes CB homogenous distribution, forming good conductive paths for ion transport. Beyond this, higher CB contents, which are CB6 and CB7 resulted in conductivity reductions ascribed to excessive filler inducing agglomeration, ionic channel blockage, and increased resistance [ 36 , 37 ]. These results demonstrate that while the unmodified PVA-EC-PC-KI matrix (CB1) has better ion transport, addition of carbon black able to control ionic conductivity depending on concentration. Moderate loading of CB, which is CB5 increases conductivity through enhanced amorphous character and providing conductive paths, whereas high carbon black limits the polymer network and impedes ion mobility. These findings are useful in understanding how multi-component GPEs composition can be tailored towards better electrochemical performance [ 38 ]. For comparison, based on previous study by Negi et al. [ 37 ] who also used CB as nanofiller for PEO-based polymer electrolyte preparation achieved maximum ionic conductivity of 1.20×10 − 5 S cm − 1 at content of 0.05 wt.%. In another report by Mohan et al. [ 39 ] has reported that GPE based on polymethyl methacrylate (PMMA)-lithium iodide (LiI), 1-propyl-3-methylimidazolium iodide (PMIMI) obtained an optimum ionic conductivity of 3.32 × 10 − 3 S cm − 1 with the addition of 0.57 wt.% of CB. Barzegar et al. [ 40 ] also investigated a GPE system based on PVA- potassium hydroxide (KOH) with addition of CB as nanofiller. The authors proposed that when CB is added PVA-KOH GPE improves its conductivity which facilitates fast ion transport [ 41 , 42 ]. The present PVA-based GPE system exhibits higher conductivity than the other polymer used with CB as nanofiller due to its excellent characteristics. The incorporation of CB into the PVA matrix proved that CB can further enhances ionic conductivity by promoting the formation of continuous conductive pathways, as observed in the optimal performance of GPE at 12 wt.% (CB5). However, if further increased the amount of CB the ionic conductivity of GPE would be low due to CB aggregation. 4. Conclusion In the present work PVA-based GPEs incorporated carbon black nanofillers were effectively developed and characterized. XRD analysis revealed that the addition of CB altered the crystallinity of the GPE matrix. The amorphous content and ionic transport within the polymer matrix, CB5 (12 wt.%) exhibited the highest ionic conductivity of \((1.18\pm0.00)\times10⁻²\text{S}\text{c}\text{m}⁻¹\) via increased formation of conductive pathways. FTIR analysis identified strong intermolecular interactions such as hydrogen bonding, ion-dipole, and dipole-dipole interactions which reduced crystalline domains and expanded amorphous regions, facilitating the ion transport easily. Additionally, future research could explore with other polymers such as poly (ethylene oxide) (PEO), poly (vinylidene fluoride) (PVDF) and poly(acrylonitrile) (PAN), and blending different high-quality nanofillers to achieve maximum conductivity, stability, and device performance. Declarations Author Contribution A.A. wrote and edited the manuscript. C.G. prepared the gel polymer electrolytes and wrote the main manuscript text. P.Q.B. prepared the gel polymer electrolytes. A.R.M. performed the X-ray diffraction measurements. N.M. analyzed the X-ray diffraction results. M.H. obtained the Fourier-transform infrared spectroscopy results. N. measured the electrochemical impedance spectroscopy results. I.M. analyzed the electrochemical impedance spectroscopy results. M.F. finalized the reference list. M.F. analyzed the Fourier-transform infrared spectroscopy results, edited the manuscript, and finalized it. All authors read and approved the final manuscript. Acknowledgement Authors thanks Universiti Sains Malaysia, Bridging Grant with Project No: R501-LR-RND003-0000002095-0000 References Yang H, Wu N (2022) Ionic conductivity and ion transport mechanisms of solid-state lithium‐ion battery electrolytes: A review. Energy Sci Eng 10(5). 10.1002/ese3.1163 Rayung M, Aung MM, Azhar SC, Abdullah LC, Su’ait MS, Ahmad A et al (2020) Bio-based polymer electrolytes for electrochemical devices: Insight into the ionic conductivity performance. Materials 13(4):838. 10.3390/ma13040838 Han L, Wang L, Chen Z, Kan Y, Hu Y, Zhang H et al (2023) Incombustible polymer electrolyte boosting safety of solid-state lithium batteries: A review. Adv Funct Mater 33(32). 10.1002/adfm.202300892 Ahmed MS, Islam M, Raut B, Yun S, Kim HY, Nam KW (2024) A comprehensive review of functional gel polymer electrolytes and applications in lithium-ion battery. Gels 10(9):563. 10.3390/gels10090563 Aruchamy K, Ramasundaram S, Divya S, Chandran M, Yun K, Oh TH (2023) Gel polymer electrolytes: Advancing solid-state batteries for high-performance applications. Gels 9(7):585. 10.3390/gels9070585 Abubakar Abdulkadir B, Setiabudi HD (2025) Progress and accomplishments in polymer blend electrolytes for electrochemical energy storage: A comprehensive review. Polymer-Plastics Technol Mater 64(14):2143–2178. 10.1080/25740881.2025.2511698 Behzadi Pour G, Nazarpour Fard H, Fekri Aval L (2024) A comparison of the electrical properties of gel polymer electrolyte-based supercapacitors: A review of advances in electrolyte materials. Gels 10(12):803. 10.3390/gels10120803 Rahim AA, Shamsuri NA, Adam AA, Aziz MF, Hamsan MH, Rusdi H et al (2024) Characterization of nanocomposite polyvinyl alcohol/cellulose acetate blend gel polymer electrolytes for supercapacitor application. J Energy Storage 97:112964. 10.1016/j.est.2024.112964 Raut P, Kishnani V, Mondal K, Gupta A, Jana SC (2022) A Review on gel polymer electrolytes for dye-Sensitized solar cells. Micromachines 13(5):680. 10.3390/mi13050680 Aziz MF, Rahim AA, Rais ARM (2025) Unveiling ionic conductivity and ion transport properties in polyvinyl alcohol-based gel polymer electrolytes with quaternary ammonium iodide. J Polym Mater 42(4):1097–1099. 10.32604/jpm.2025.071129 Ling CK, Aung MM, Abdullah LC, Lim HN, Uyama H (2020) A short review of iodide salt usage and properties in dye sensitized solar cell application: Single vs binary salt system. Sol Energy 206:1033–1038. 10.1016/j.solener.2020.06.055 Farhana NK, Saidi NM, Bashir S, Ramesh S, Ramesh K (2021) Review on the revolution of polymer electrolytes for dye-sensitized solar cells. Energy Fuels 35(23):19320–19350. 10.1021/acs.energyfuels.1c03039 Luo Y, Shi Z, Qiao S, Tong A, Liao X, Zhang T et al (2024) Advances in nanomaterials as exceptional fillers to reinforce carbon fiber-reinforced polymers composites and their emerging applications. Polym Compos 46(1):54–80. 10.1002/pc.29027 Al-Kelani M, Buthelezi N (2024) Advancements in medical research: Exploring Fourier transform infrared (FTIR) spectroscopy for tissue, cell, and hair sample analysis. Skin Res Technol 30(6). 10.1111/srt.13733 Smith B (2016) The infrared spectroscopy of alkenes. Spectrosc Online. ;31(11) Lin SY, Cheng WT, Wei YS, Lin HL (2011) DSC-FTIR microspectroscopy used to investigate the heat-induced intramolecular cyclic anhydride formation between Eudragit E and PVA copolymer. Polym J 43(6):577–580. 10.1038/pj.2011.15 Fatimah S, Ragadhita R, Husaeni DFA, Nandiyanto ABD (2021) How to calculate crystallite size from x-ray diffraction (XRD) using Scherrer method. ASEAN J Sci Eng 2(1):65–76. 10.17509/ajse.v2i1.37647 Aziz MF, Rahim AA, Razak ESA, Jaaffar SNA, Buraidah MH, Shukur MF (2025) Enhanced ion transport and structural dynamics in gel polymer electrolytes containing a plasticizer prospect for DSSC application. Ionics 31(6):6103–6115. 10.1007/s11581-025-06270-9 Noer Z, MN N, Bukit N, Juwairiah, Susilawati (2018) Ikhwanuddin. Characterization of low-density polyethylene (LDPE)/carbon black (CB) nanocomposite-based packaging material. Journal of Physics: Conference Series. ;1120(1):012066. 10.1088/1742-6596/1120/1/012066 Ungár T, Gubicza J, Tichy G, Pantea C, Zerda TW (2004) Size and shape of crystallites and internal stresses in carbon blacks. Compos A Appl Sci Manuf 36(4):431–436. 10.1016/j.compositesa.2004.10.017 Zhang S, Cui Y, Wu B, Song R, Song H, Zhou J et al (2013) Control of graphitization degree and defects of carbon blacks through ball-milling. RSC Adv 4(1):505–509. 10.1039/c3ra44530e Cattaruzza M, Fang Y, István Furó, Lindbergh G, Liu F, Johansson M (2025) Hybrid polymer–liquid lithium ion electrolytes: Effect of carbon black during polymerization-induced phase separation. Polymer 326:128341. 10.1016/j.polymer.2025.128341 Alzahrani HAH (2022) CuO and MWCNTs nanoparticles filled PVA-PVP nanocomposites: Morphological, optical, dielectric, and electrical characteristics. IntechOpen eBooks 32(5). 10.5772/intechopen.105810 Chen J, Liu B, Gao X, Xu D (2018) A review of the interfacial characteristics of polymer nanocomposites containing carbon nanotubes. RSC Adv 8(49):28048–28085. 10.1039/c8ra04205e Tareen MHK, Hussain F, Zubair Z, Aslam S, Saleem T, Awais M et al (2022) Effects of carbon black on epoxidized natural rubber composites: Rheological, abrasion, and mechanical study. J Compos Mater 56(29):4473–4485. 10.1177/00219983221134512 Fredi G, Zimmerer C, Scheffler C, Pegoretti A (2020) Polydopamine-coated paraffin microcapsules as a multifunctional filler enhancing thermal and mechanical performance of a flexible epoxy resin. J Compos Sci 4(4):174. 10.3390/jcs4040174 Fang B, Wang T, Chen X, Jin T, Zhang R, Zhuang W (2015) Modeling vibrational spectra of ester carbonyl stretch in water and DMSO based on molecular dynamics simulation. J Phys Chem B 119(38):12390–12396. 10.1021/acs.jpcb.5b06541 Chauhan APS, Chawla K (2016) Comparative studies on graphite and carbon black powders, and their dispersions. J Mol Liq 221:292–297. 10.1016/j.molliq.2016.05.043 Manikandan KM, Arunagiri Yelilarasi, Saravanakumar SS, Althomali RH, Khan A, Abualnaja KM et al (2021) The effect of plasticizers on the polypyrrole-poly(vinyl alcohol)-based conducting polymer electrolyte and its application in semi-transparent dye-sensitized solar cells. Membranes 11(10):791. 10.3390/membranes11100791 Basha SKS, Sundari GS, Kumar KV (2016) Studies on electrical properties of potassium acetate complexed with polyvinyl alcohol for electrochemical cell applications. Materials Today: Proceedings. ;3(1):11–20. 10.1016/j.matpr.2016.01.109 Song L, Sun S, Zhao X (2023) Ethylene carbonate plasticized polymer electrolyte for chloride ion batteries with enhanced reversible capacity. Solid State Ionics 399(116314):116314. 10.1016/j.ssi.2023.116314 Liu Q, Zhao Y, Gao S, Yang X, Fan R, Zhi M et al (2021) Recent advances in the flame retardancy role of graphene and its derivatives in epoxy resin materials. Compos Part A: Appl Sci Manufac 149(106539):106539. 10.1016/j.compositesa.2021.106539 Smith BC (2022) The infrared spectra of polymers, VI: Polymers with C-O bonds. Spectroscopy 37(5):15–19. 10.56530/spectroscopy.ly3071f5 Patel M, Mishra K, Chaudhary NA, Madhani V, Chaudhari JJ, Kumar D (2024) A sodium ion conducting gel polymer electrolyte with counterbalance between 1-ethyl-3-methylimidazolium tetrafluoroborate and tetra ethylene glycol dimethyl ether for electrochemical applications. RSC Adv 14(20):14358–14373. 10.1039/d4ra01615g Aziz S, Abdullah R, Rasheed M, Ahmed H (2017) Role of ion dissociation on DC conductivity and silver nanoparticle formation in PVA:AgNt based polymer electrolytes: Deep insights to ion transport mechanism. Polymers 9(12):338. 10.3390/polym9080338 Negi SS, Rawat S, Singh PK, Pandey SP, Yadav T, Srivastava M et al (2024) Influence of carbon black on conductivity and structure of polyethylene oxide based polymer electrolyte film. Macromolecular Symposia 413(1):2300104. 10.1002/masy.202300104 Negi SS, Rawat S, Singh PK, Savilov SV, Yadav T, Yahya MZA et al (2024) Conducting carbon black nano-filler doped polymer electrolyte for electrochemical application. ChemistrySelect 9(25). 10.1002/slct.202400847 Shamsuri NA, Halim SNA, Aziz SB, Abdulwahid RT, Alias Y, Kadir MFZ (2024) Bio-derived gel polymer electrolytes from zein and honey blends integrated with ammonium nitrate for electrical double layer capacitors. J Energy Storage 102:113909. 10.1016/j.est.2024.113909 Mohan K, Swapnil Dolui, Nath BC, Bora A, Sharma S (2017) Swapan Kumar Dolui. A highly stable and efficient quasi solid-state dye sensitized solar cell based on polymethyl methacrylate (PMMA)/carbon black (CB) polymer gel electrolyte with improved open circuit voltage. Electrochim Acta 247:216–228. 10.1016/j.electacta.2017.06.062 Barzegar F, Dangbegnon JK, Bello A, Momodu DY, Johnson AT, Manyala N (2015) Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors. AIP Adv 5(9). 10.1063/1.4931956 Raut P, Kishnani V, Mondal K, Gupta A, Jana SC (2022) A review on gel polymer electrolytes for dye-sensitized solar cells. Micromachines 13(5):680. 10.3390/mi13050680 Khan Z, Ail U, Ajjan FN, Phopase J, Kim N, Kumar D et al (2022) Towards printable water-in-polymer salt electrolytes for high power organic batteries. J Power Sources 524:231103. 10.1016/j.jpowsour.2022.231103 Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 31 Mar, 2026 Reviews received at journal 24 Mar, 2026 Reviews received at journal 17 Mar, 2026 Reviews received at journal 14 Mar, 2026 Reviewers agreed at journal 09 Mar, 2026 Reviewers agreed at journal 05 Mar, 2026 Reviews received at journal 04 Mar, 2026 Reviewers agreed at journal 03 Mar, 2026 Reviewers agreed at journal 03 Mar, 2026 Reviewers agreed at journal 03 Mar, 2026 Reviewers agreed at journal 03 Mar, 2026 Reviewers invited by journal 03 Mar, 2026 Editor assigned by journal 02 Mar, 2026 Submission checks completed at journal 02 Mar, 2026 First submitted to journal 23 Feb, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8952004","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":601281309,"identity":"18db6d42-e568-4e0f-abce-2af66ece2edc","order_by":0,"name":"A. A. Rahim","email":"","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"A.","lastName":"Rahim","suffix":""},{"id":601281310,"identity":"895447fa-4873-4b94-815a-dd0afcc6441d","order_by":1,"name":"C. G. Er","email":"","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":false,"prefix":"","firstName":"C.","middleName":"G.","lastName":"Er","suffix":""},{"id":601281311,"identity":"c8ba31f2-10a0-4536-89f6-1725d2d9696b","order_by":2,"name":"P. Q. B. Mazlan","email":"","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":false,"prefix":"","firstName":"P.","middleName":"Q. B.","lastName":"Mazlan","suffix":""},{"id":601281312,"identity":"30e83504-e8bc-48d4-935c-57c7b59a6ec2","order_by":3,"name":"A. R. M. Rais","email":"","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":false,"prefix":"","firstName":"A.","middleName":"R. M.","lastName":"Rais","suffix":""},{"id":601281313,"identity":"f61e8450-c50e-442a-8590-ef305088ce5d","order_by":4,"name":"N. M. Disa","email":"","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":false,"prefix":"","firstName":"N.","middleName":"M.","lastName":"Disa","suffix":""},{"id":601281314,"identity":"51e6396d-d927-4e19-b610-e7fbef015e20","order_by":5,"name":"M. H. Buraidah","email":"","orcid":"","institution":"Centre for Ionics University of Malaya, Universiti Malaya","correspondingAuthor":false,"prefix":"","firstName":"M.","middleName":"H.","lastName":"Buraidah","suffix":""},{"id":601281315,"identity":"781c759f-eae4-4117-8476-73c3cbbda4f8","order_by":6,"name":"N. Shamshurim","email":"","orcid":"","institution":"Universiti Putra Malaysia","correspondingAuthor":false,"prefix":"","firstName":"N.","middleName":"","lastName":"Shamshurim","suffix":""},{"id":601281316,"identity":"d7d986b5-59d3-4b64-a33d-d720f4c202d9","order_by":7,"name":"I. M. Noor","email":"","orcid":"","institution":"Universiti Putra Malaysia","correspondingAuthor":false,"prefix":"","firstName":"I.","middleName":"M.","lastName":"Noor","suffix":""},{"id":601281317,"identity":"8e7d1baa-68f9-456b-9bee-ffae15867a9a","order_by":8,"name":"M. F. Shukur","email":"","orcid":"","institution":"Universiti Teknologi PETRONAS","correspondingAuthor":false,"prefix":"","firstName":"M.","middleName":"F.","lastName":"Shukur","suffix":""},{"id":601281318,"identity":"ebd79a6c-cbf8-42d6-ac5b-a95449fb842e","order_by":9,"name":"M. F. Aziz","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA4UlEQVRIiWNgGAWjYBAC9gYkzgGGCiK08BxA0XKGVC0MjG3EaGE/+/DBhz+H5c3Zjz88+HPeYXvdBu40CbxaeNKNDWfwHDbc2ZOQcEBy2+HEbQd4t+HVYs+QxibNI3GYccOBhAMHDLcdTjAjpIWH/xn77z8Gh+03nH/YcCBxzmF7wlok0tiYGRIOJ264kcxw4GDDYUaCDuOReMYs2XMgPXnDjWcMBxuOpSduO8y72QK/w9IYP/z4Y2274Xz6448/aqztzY73bryBTwsWwMzAgtdh2DV9IFnLKBgFo2AUDGcAAFZTUPvqEabNAAAAAElFTkSuQmCC","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":true,"prefix":"","firstName":"M.","middleName":"F.","lastName":"Aziz","suffix":""}],"badges":[],"createdAt":"2026-02-24 03:08:28","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8952004/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8952004/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104075781,"identity":"e09ec9a7-32c0-45c1-aee6-adff93c7ed62","added_by":"auto","created_at":"2026-03-06 13:06:17","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":76580,"visible":true,"origin":"","legend":"\u003cp\u003eXRD patterns of PVA-based GPEs with varying concentration of carbon black.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/1c03161495466d33f7b38961.png"},{"id":104075785,"identity":"5b8bfc7b-5842-41c1-9291-b27e9d5b6410","added_by":"auto","created_at":"2026-03-06 13:06:18","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":290571,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of PVA–EC-PC–KI–CB systems (CB1 to CB7) in the wavenumber range of (a) 3800 to 2800 cm\u003csup\u003e–1\u003c/sup\u003e and (b) 2000 to 800 cm\u003csup\u003e–1\u003c/sup\u003e.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/b7b801a9387510eb12665379.png"},{"id":104075783,"identity":"25523cdd-86b9-44c1-b56d-7d727330a75f","added_by":"auto","created_at":"2026-03-06 13:06:17","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":171716,"visible":true,"origin":"","legend":"\u003cp\u003eInteraction in the polymer-salt-nanofiller (PVA-EC-PC-KI-CB) system.\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/8d51779463e968334cd07d17.png"},{"id":104403430,"identity":"0d542d90-e470-47db-934d-095ae1c01dba","added_by":"auto","created_at":"2026-03-11 12:18:20","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":71643,"visible":true,"origin":"","legend":"\u003cp\u003eThe Nyquist plots for PVA-EC-PC-KI-CB GPEs system with varying carbon black concentrations.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/79257616acd55bca352589f4.png"},{"id":104075784,"identity":"e1735126-a077-4884-9e12-95ed0268058c","added_by":"auto","created_at":"2026-03-06 13:06:17","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":15060,"visible":true,"origin":"","legend":"\u003cp\u003eConductivity at 25\u003csup\u003eo\u003c/sup\u003eC against carbon black (CB) concentrations.\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/a539152b1522e1ee92a6b8f1.png"},{"id":105562485,"identity":"463e2db1-8f90-45fe-9df8-ba165b111beb","added_by":"auto","created_at":"2026-03-27 12:41:18","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1222126,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8952004/v1/ba0d7b70-93f5-459c-bb54-4b853339e3d1.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Carbon Black-Modified Polyvinyl Alcohol-Based Gel Polymer Electrolytes with Enhanced Ionic Conductivity","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eThe growing demand for environmentally friendly and efficient energy conversion systems has increased the interest of researchers to continuously explore innovative materials and technologies to enhance electrochemical device performance. Electrochemical devices like dye-sensitized solar cells, lithium-ion batteries, and supercapacitors utilize electrolytes to transport ions between electrodes, which is crucial for energy conversion and storage. Liquid electrolytes with high ionic conductivity (~\u0026thinsp;10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e \u0026minus;\u0026thinsp;10\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) are widely employed in these devices [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, these traditional liquid electrolytes have issues relating to leakage and flammability [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGel polymer electrolytes (GPEs) have drawn interest as alternatives to liquid electrolytes as they offer enhanced safety, mechanical integrity, and flexibility [\u003cspan additionalcitationids=\"CR4\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. It has been reported that the ionic conductivity of GPEs have achieved in the range of 10\u003csup\u003e\u0026minus;\u0026thinsp;4\u003c/sup\u003e \u0026minus;\u0026thinsp;10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Some of polymers that has been reported in synthesis of GPE are polyvinyl alcohol (PVA), polyethylene glycol (PEO), polymethyl methacrylate (PMMA), and polyacrylonitrile (PAN) [\u003cspan additionalcitationids=\"CR6\" citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. PVA is a semicrystalline and hydrophilic, which often used as a host polymer in GPE preparation due to its excellent chemical stability, nontoxicity and biodegradability [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. However, the high crystallinity due to the semi-crystalline nature of polymers, limits ionic mobility, leading to low ionic conductivity. These requiring modifications to provide better performance of GPEs.\u003c/p\u003e \u003cp\u003eThus, to improve the performance of GPEs, various studies and methods have been explored including addition of salts, plasticizers or additives, and nanofillers. Dopant salt in polymer electrolytes provide additional charge carriers which help to enhance electrical stability and ionic conductivity in a variety of solvents. Salt selection for the preparation of GPEs is essential for optimal electrochemical applications, with low lattice energy being significant for improved salt dissociation and ion transport. Previous studies have been used iodide salts in preparation of GPEs especially in dye-sensitized solar cell (DSSC) application like potassium iodide (KI), lithium iodide (LiI), and sodium iodide (NaI) [\u003cspan additionalcitationids=\"CR10\" citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. KI is one of the most common salts used as it has lower lattice energy of 627 kJ mol\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and small cations which helps in ion dissociation [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRecent studies have focused on incorporation of nanofillers to improve the performance of GPEs since they can reduce the crystallinity in polymer matrix. Carbon black (CB) is among of the nanofillers, is a conductive carbon-based nanomaterial which offers multiple advantages. CB has a large surface area, excellent chemical stability, and has the potential to improve both structural and electrochemical properties of polymer matrices [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Despite its wide usage in batteries and capacitors, its application in PVA-based GPEs remains underexplored.\u003c/p\u003e \u003cp\u003eThis study aims to investigate the effects of CB loading on the structural, spectroscopic, and ionic conductivity properties of PVA-based GPEs with KI as dopant salt. The results provide new insights into the role of carbon-based nanofillers in tailoring polymer electrolyte performance for electrochemical applications.\u003c/p\u003e"},{"header":"2. Methodology","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\n \u003ch2\u003e2.1 Materials\u003c/h2\u003e\n \u003cp\u003eDimethyl sulfoxide (DMSO) was obtained from R\u0026amp;M Chemicals. Polyvinyl alcohol (PVA) (99% hydrolysed), ethylene carbonate (EC), propylene carbonate (PC), and carbon black (CB), and iodine (I\u003csub\u003e2\u003c/sub\u003e) crystals were purchased from Sigma Aldrich. Potassium iodide (KI) was obtained from Univar Analytical Reagent.\u003c/p\u003e\n\u003c/div\u003e\n\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003e2.2 Preparation of Gel Polymer Electrolyte (GPE)\u003c/h2\u003e\n \u003cdiv class=\"BlockQuote\"\u003e\n \u003cp\u003eGel polymer electrolyte (GPE) was synthesized by employed a solution-casting technique. A high-purity polyvinyl alcohol (PVA) was employed as the host polymer, potassium iodide (KI) as dopant salt, and carbon black (CB) as the nanofiller. Dimethyl sulfoxide (DMSO) was used as the solvent, while ethylene carbonate (EC) and propylene carbonate (PC) acted as plasticizers to enhance ionic mobility. Initially, 0.42 g of KI salt was dissolved in 2 ml of DMSO with EC \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\left(0.3g\\right)\\)\u003c/span\u003e\u003c/span\u003e and PC \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\left(0.33ml\\right)\\)\u003c/span\u003e\u003c/span\u003e at 30\u0026deg;C for 15 minutes. Separately, 0.2 g PVA was dissolved in 2 ml of DMSO at \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(75℃\\)\u003c/span\u003e\u003c/span\u003e under agitation at 420 rpm for 20 minutes. Both solutions were combined and stirred continuously at 80\u0026deg;C for 30 minutes, followed by sequential addition of CB at varied concentration until complete dissolution. The resulting samples, labelled as CB1-CB7, contained 0, 3, 6, 9, 12, 15, and 18 wt.% carbon black, respectively. Lastly, iodine (I\u003csub\u003e2\u003c/sub\u003e) crystals were added at \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(45℃\\)\u003c/span\u003e\u003c/span\u003e for 10 minutes. The amount of I\u003csub\u003e2\u003c/sub\u003e added was 10% molar ratio of the total iodide ions in salt. The final mixture of GPE samples were transferred into veils and cured in a desiccator to prevent contamination and ensure uniformity. The designation and composition of GPE samples were listed in Table \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\n \u003c/div\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eDesignation and composition of PVA-KI-EC-PC-CB GPE system with fixed amount of PVA (0.2 g), KI (0.294 g), EC (0.3 g), PC (0.4 g), and DMSO (2 ml), and I\u003csub\u003e2\u003c/sub\u003e (0.646 g).\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eDesignation\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCB \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((\\text{w}\\text{t}.\\text{%})\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\"\u003e\u003cp\u003eCB (g)\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB1\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0.0000\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB2\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0.2388\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB3\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0.5015\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB4\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e9\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0.6515\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB5\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e0.8815\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB6\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e1.0887\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\"\u003e\u003cp\u003eCB7\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e18\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\"\u003e\u003cp\u003e1.2903\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Fourier transform infrared spectroscopy (FTIR)\u003c/h2\u003e\u003cp\u003eThe FTIR spectra were recorded on FTIR spectrophotometer (iS10, Thermo Scientific) with an attenuated total reflectance (ATR) attachment, allowing for direct analysis without additional sample treatment [\u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e]. Measurements were carried out in the 500\u0026ndash;4000 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e range with a spectral resolution of 2 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e.\u003c/p\u003e\u003cp\u003eFTIR spectra were referenced with those of pure samples (PVA, KI, EC, PC, and CB), looking for shifts in peaks, differences in intensity, and new absorption bands, especially with respect to the \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(O-H\\)\u003c/span\u003e\u003c/span\u003e stretch (~\u0026thinsp;3300 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e), \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(C=O\\)\u003c/span\u003e\u003c/span\u003e stretch (~\u0026thinsp;1700 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e), \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(C-O-C\\)\u003c/span\u003e\u003c/span\u003e stretch (~\u0026thinsp;1100 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e), and iodide-associated vibrations between 500\u0026ndash;800 cm\u003csup\u003e\u0026ndash;1\u003c/sup\u003e for easier identification of specific chemical interactions [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe spectroscopic alteration noticed was utilized to infer potential interactions among plasticizers, polymer, salt, and nanofiller. The incorporation of carbon black was also specifically investigated for its influence on the network of hydrogen bonding of PVA and its impacts on subsequent ionic conductivity. Such findings confirmed the development of the PVA-based GPE system and provided insight into the structural role played by carbon black as a nanofiller in enhancing the polymer matrix.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec6\" class=\"Section2\"\u003e\u003ch2\u003e2.4 X-ray diffraction (XRD)\u003c/h2\u003e\u003cp\u003eThe XRD analysis was carried out on a PANalytical X\u0026apos;Pert PRO MRD PW3040 diffractometer with Cu-K\u0026alpha; radiation (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\lambda=0.154nm\\)\u003c/span\u003e\u003c/span\u003e) at 40 kV and 30 mA. Diffraction patterns were registered in the \u003cem\u003e2\u0026theta;\u003c/em\u003e range between \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(5^\\circ-55^\\circ\\)\u003c/span\u003e\u003c/span\u003e with a scan rate of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(2^\\circmin⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e and a count time of 1s per step, which was the optimal compromise between data quality and efficiency.\u003c/p\u003e\u003cp\u003eThe obtained diffraction spectra were analysed to determine the degree of crystallinity according to the peak sharpness and intensity, where sharp and narrow peaks indicated crystalline domains and broad peaks corresponded to amorphous regions. The crystallite size (\u003cem\u003eD\u003c/em\u003e) was estimated using the Debye-Scherrer equation [\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e]:\u003c/p\u003e\u003cdiv id=\"Equa\" class=\"Equation\"\u003e\u003cdiv class=\"mathdisplay\" id=\"FileID_Equa\" name=\"EquationSource\"\u003e$$D=\\frac{K\\lambda}{\\beta\\text{cos}\\theta}$$\u003c/div\u003e\u003c/div\u003e\u003cp\u003e(1)\u003c/p\u003e\u003cp\u003ewhere \u003cem\u003eK\u003c/em\u003e is the Scherrer constant (0.98), \u003cem\u003e\u0026lambda;\u003c/em\u003e is the X-ray wavelength (0.154 nm), and \u003cem\u003e\u0026beta;\u003c/em\u003e is the full width at half maximum (FWHM).\u003c/p\u003e\u003cp\u003eFurther analysis was dedicated to identifying the characteristic diffraction peaks of PVA, CB, KI, and I\u003csub\u003e2\u003c/sub\u003e and assessing the structural changes induced by CB addition as a nanofiller.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e\u003ch2\u003e2.5 Electrochemical impedance spectroscopy (EIS) Measurement\u003c/h2\u003e\u003cp\u003eElectrochemical impedance spectroscopy (EIS) was conducted using an electrochemical workstation, which is HIOKI 3532-50 LCR HiTester in the frequency range of 50 Hz to 100 kHz at room temperature (25\u0026deg;C). This experiment was designed to study the ionic conductivity and charge transfer behaviour of the PVA-based GPE. The gel electrolyte membrane was sandwiched between two stainless steel electrodes, and the setup was sealed to minimize the interference of external humidity to accurately measure bulk resistance and ionic conductivity.\u003c/p\u003e\u003cp\u003eAn AC voltage of 10 mV was applied to maintain the system behaviour pseudo-linear for the response to obey Ohm\u0026apos;s law and to be modelled with certainty. The resultant impedance spectra were plotted in the form of Nyquist plots, and the bulk resistance (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}_{b}\\)\u003c/span\u003e\u003c/span\u003e) was identified from the intercept of the real axis at high frequency. The ionic conductivity (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\sigma\\)\u003c/span\u003e\u003c/span\u003e) was then calculated using the relation [\u003cspan class=\"CitationRef\"\u003e18\u003c/span\u003e]:\u003c/p\u003e\u003cdiv id=\"Equb\" class=\"Equation\"\u003e\u003cdiv class=\"mathdisplay\" id=\"FileID_Equb\" name=\"EquationSource\"\u003e$$\\sigma=\\frac{t}{{R}_{b}A}$$\u003c/div\u003e\u003c/div\u003e\u003cp\u003e(2)\u003c/p\u003e\u003cp\u003ewhere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(t\\)\u003c/span\u003e\u003c/span\u003e is the electrolyte thickness \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\left(0.2cm\\right)\\)\u003c/span\u003e\u003c/span\u003e, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}_{b}\\)\u003c/span\u003e\u003c/span\u003e is the bulk resistance, and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(A\\)\u003c/span\u003e\u003c/span\u003e is the stainless-steel electrode contact area \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\left(2.010619{cm}^{2}\\right)\\)\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e\u003cp\u003eThe influence of CB as a nanofiller was investigated through monitoring \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}_{b}\\)\u003c/span\u003e\u003c/span\u003e variation and the corresponding variation in ionic conductivity.\u003c/p\u003e\u003c/div\u003e"},{"header":"3. Results and Discussion","content":"\u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003e3.1 X-ray diffraction (XRD) Analysis\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the XRD patterns of GPEs containing CB at different concentrations (CB1-CB7). The pristine carbon black exhibited an unmistakable crystalline peak at 2θ\u0026thinsp;\u0026asymp;\u0026thinsp;26.39\u0026deg;, which fell within the typical 25\u0026ndash;30\u0026deg; range, confirming its natural crystallinity. This peak was utilized as a reference point to evaluate changes in the structure of modified GPE samples. From CB1 to CB4, there was a stepwise decrease in crystallite size, where CB4 exhibited the highest full width at half maximum (FWHM) of 0.12 rad as listed in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The broad peak and small crystallite size of CB4 indicate higher structural disorder as well as higher amorphous content. Thus, these improve the ionic conductivity of GPE by reducing crystallinity and providing flexible pathways for ion transport within the polymer matrix.\u003c/p\u003e \u003cp\u003eThe same trends have been reported by Noer et al. [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e] that synthesized a low-density polyethylene (LDPE)-CB nanocomposites, where lower loadings of CB at 5 wt.% consist of more dispersed fillers and greater loadings consist of distinct agglomeration .Ung\u0026aacute;r et al. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] also explained that the widening of the peak in CB is caused by extremely small crystallites, lattice strain, and uneven particle shape, which inhibit ordered stacking. Hence, CB1-CB4 signify that more carbon black content disturbs the crystalline packing in the polymer matrix and prefers amorphous forms.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn contrast, CB5-CB7 revealed narrower peaks with small shifts towards higher 2θ values. Peak locations were recorded at 26.45\u0026deg; (CB5), 26.08\u0026deg; (CB6), and 26.39\u0026deg; (CB7), while crystallite size was increased to 10.05 nm for CB7 and FWHM correspondingly, indicating higher crystallinity. This improvement is attributed to compositional effects for improved graphitic stacking, thermal treatment, or catalytic effects. Zhang et al. [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] reported that ball-milling of CB can induce more ordered graphitic domains, as observed in higher peak intensity, 2θ shift towards higher values, and less amorphous carbon content. Consistently, originally low-crystallinity CB in the current study revealed a broad shoulder between 15\u0026deg; and 23.7\u0026deg; due to amorphous carbon, whereas CB5-CB7 exhibited structural reordering.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe XRD peak position and FWHM.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(2\\theta\\left(^\\circ\\right)\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFWHM (rad)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePure carbon black\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e21.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.03\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20.98\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e25.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.06\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24.59\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.12\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCB7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eMoreover, at CB5-CB7 also where it being observed that crystallinity increase is due to agglomeration. CB aggregation limits the uniform ion distribution which lead to low ionic conductivity. The increase in the concentration of CB could lead to hydrophobicity and causing incompatibility with the polymer matrix, which could enhance surface energy and cause partial structural reordering [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. This phenomenon corresponds to the increased graphitic stacking in CB5-CB7. The trends are also consistent with the Scherrer equation in which FWHM is inversely related to crystallite size.\u003c/p\u003e \u003cp\u003eOverall, XRD information indicates that CB4 is the most amorphous among all samples, whereas CB5-CB7 are more crystalline than pure carbon black, suggesting that they are suitable for applications requiring well-ordered carbon structures.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003e3.2 FTIR analysis\u003c/h2\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the FTIR spectra of the PVA-EC-PC-KI-CB system, highlighting key vibrational changes that reflect molecular interactions among the components. The C\u0026thinsp;=\u0026thinsp;O stretching region (~\u0026thinsp;1770\u0026ndash;1777 cm⁻\u0026sup1;) shows slight shifts from CB1 to CB7, indicating coordination between the carbonate groups (EC \u0026amp; PC) and K⁺ ions, as well as possible interactions with CB surfaces. The C\u0026thinsp;=\u0026thinsp;C stretching (~\u0026thinsp;1650 cm⁻\u0026sup1;) in carbon black suggests weak π-π interactions or hydrogen bonding with the polymer matrix, while the broad O-H stretching band (~\u0026thinsp;3300\u0026ndash;3400 cm⁻\u0026sup1;) confirms strong hydrogen bonding among PVA, KI, and CB.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eC-H stretching (3000\u0026thinsp;\u0026minus;\u0026thinsp;2850 cm⁻\u003csup\u003e1\u003c/sup\u003e) reflects contributions from PVA, EC, and PC, influenced by hydrogen bonding, ion-dipole interactions, and plasticization effects. Shifts in the C-O (1004\u0026ndash;1014 cm⁻\u003csup\u003e1\u003c/sup\u003e) and O-H bending (1404\u0026ndash;1438 cm⁻\u003csup\u003e1\u003c/sup\u003e) regions further indicate dynamic polymer-filler and polymer-ion interactions. The C\u0026thinsp;=\u0026thinsp;C bending vibrations (945\u0026ndash;952 cm⁻\u003csup\u003e1\u003c/sup\u003e) demonstrate π\u0026ndash;π stacking and electronic coupling between CB and the polymer matrix, enhancing filler dispersion and interfacial interactions. The summary of the FTIR peaks for PVA-EC-PC-KI-CB system is shown in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eThus, all the spectral shifts highlighted that the hydrogen bonding, ion-dipole interactions and van der Waals forces all play crucial roles in the complex system of GPE. Increasing CB content will affect the balance between mechanical strength and ionic transport, providing insight into optimizing the performance of the GPE [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e illustrates the interaction in the polymer-salt-nanofiller system.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eFTIR wavenumber assignments for PVA-EC-PC-KI-CB system at varying CB concentrations.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"9\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"8\" nameend=\"c8\" namest=\"c1\"\u003e \u003cp\u003eWavenumber (cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c9\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eReference\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eAssignments\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"7\" nameend=\"c8\" namest=\"c2\"\u003e \u003cp\u003ePVA-EC-PC-KI-CB\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCB1\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCB2\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCB3\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eCB4\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eCB5\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eCB6\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eCB7\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO-H Stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3326\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3294\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e3276\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3361\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e3334\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e3301\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC-H Stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2936\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2924\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2924\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2931\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2923\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e2924\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e2931\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u0026thinsp;=\u0026thinsp;O Stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1777\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1771\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1775\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1774\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1776\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u0026thinsp;=\u0026thinsp;C Stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1651\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1647\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1647\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1653\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO-H Bending\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1421\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1438\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1405\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1404\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1405\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1405\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1409\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan additionalcitationids=\"CR30\" citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC-O Stretching\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1010\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1008\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1009\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1014\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e1004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e1012\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e, \u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u0026thinsp;=\u0026thinsp;C Bending\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e950\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e949\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e945\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e948\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e951\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e951\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e952\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e[\u003cspan additionalcitationids=\"CR25\" citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.3 Electrochemical impedance spectroscopy (EIS) analysis\u003c/h2\u003e \u003cp\u003eThe bulk resistance,\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}_{b}\\)\u003c/span\u003e\u003c/span\u003e was derived from the Nyquist plots as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e below. The impedance spectra of all GPE samples, CB1 to CB7, comprised a single inclined spike line in the low-frequency region, without any discernible semicircle in the high-frequency range. This is a feature of gel polymer electrolytes, where charge transport is regulated by ionic conduction with minimal contribution from electronic pathways and insignificant charge-transfer resistance [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. The absence of a semicircle signifies high ionic mobility and minimal interfacial impedance consistent with the overall conductivity of the systems [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e, \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. It can be observed that \u003cem\u003eR\u003c/em\u003e\u003csub\u003e\u003cem\u003eb\u003c/em\u003e\u003c/sub\u003e increased upon incorporation of 3 wt.% (CB2) due to poor CB dispersion, disrupting the amorphous PVA ion conduction pathways. As CB content reached 12 wt.% (CB5), \u003cem\u003eR\u003c/em\u003e\u003csub\u003e\u003cem\u003eb\u003c/em\u003e\u003c/sub\u003e decreased owing to efficient formation of conductive pathways that enhance ion transport [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. Further addition to 15 wt.% (CB6) through 18 wt.% (CB7) increased \u003cem\u003eR\u003c/em\u003e\u003csub\u003e\u003cem\u003eb\u003c/em\u003e\u003c/sub\u003e again, resulting CB aggregation and hinders ion pathways [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eLikewise, the ionic conductivity results, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, show that CB1 which is GPE sample without the carbon black possesses the highest conductance of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((1.59\\pm0.13)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e. This is a result of the highly amorphous nature of the PVA-EC-PC-KI matrix that supports efficient dissociation of salts and mobility of ions. The initial carbon black addition at 3 wt.% (CB2) led to the significant decrease in conductivity to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((0.12\\pm0.02)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e, as the agglomeration probably upsets the polymer-ion network. An increase in adding carbon black to 6 wt.% (CB3) led to an increase in conductivity to \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((0.96\\pm0.06)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e, indicating that a low level of filler can enhance the amorphous phase and ion mobility.\u003c/p\u003e \u003cp\u003eAt 9 wt.% (CB4), conductivity slightly decreased to (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(0.75\\pm0.01)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e, whereas increasing further to yield the highest conductivity at 12 wt.% of CB5, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((1.18\\pm0.00)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e. This suggests that the optimal filler content promotes CB homogenous distribution, forming good conductive paths for ion transport. Beyond this, higher CB contents, which are CB6 and CB7 resulted in conductivity reductions ascribed to excessive filler inducing agglomeration, ionic channel blockage, and increased resistance [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e, \u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese results demonstrate that while the unmodified PVA-EC-PC-KI matrix (CB1) has better ion transport, addition of carbon black able to control ionic conductivity depending on concentration. Moderate loading of CB, which is CB5 increases conductivity through enhanced amorphous character and providing conductive paths, whereas high carbon black limits the polymer network and impedes ion mobility. These findings are useful in understanding how multi-component GPEs composition can be tailored towards better electrochemical performance [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor comparison, based on previous study by Negi et al. [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e] who also used CB as nanofiller for PEO-based polymer electrolyte preparation achieved maximum ionic conductivity of 1.20\u0026times;10\u003csup\u003e\u0026minus;\u0026thinsp;5\u003c/sup\u003e S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e at content of 0.05 wt.%. In another report by Mohan et al. [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e] has reported that GPE based on polymethyl methacrylate (PMMA)-lithium iodide (LiI), 1-propyl-3-methylimidazolium iodide (PMIMI) obtained an optimum ionic conductivity of 3.32 \u0026times; 10\u003csup\u003e\u0026minus;\u0026thinsp;3\u003c/sup\u003e S cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with the addition of 0.57 wt.% of CB. Barzegar et al. [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e] also investigated a GPE system based on PVA- potassium hydroxide (KOH) with addition of CB as nanofiller. The authors proposed that when CB is added PVA-KOH GPE improves its conductivity which facilitates fast ion transport [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. The present PVA-based GPE system exhibits higher conductivity than the other polymer used with CB as nanofiller due to its excellent characteristics. The incorporation of CB into the PVA matrix proved that CB can further enhances ionic conductivity by promoting the formation of continuous conductive pathways, as observed in the optimal performance of GPE at 12 wt.% (CB5). However, if further increased the amount of CB the ionic conductivity of GPE would be low due to CB aggregation.\u003c/p\u003e \u003c/div\u003e"},{"header":"4. Conclusion","content":"\u003cp\u003eIn the present work PVA-based GPEs incorporated carbon black nanofillers were effectively developed and characterized. XRD analysis revealed that the addition of CB altered the crystallinity of the GPE matrix. The amorphous content and ionic transport within the polymer matrix, CB5 (12 wt.%) exhibited the highest ionic conductivity of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\((1.18\\pm0.00)\\times10⁻\u0026sup2;\\text{S}\\text{c}\\text{m}⁻\u0026sup1;\\)\u003c/span\u003e\u003c/span\u003e via increased formation of conductive pathways. FTIR analysis identified strong intermolecular interactions such as hydrogen bonding, ion-dipole, and dipole-dipole interactions which reduced crystalline domains and expanded amorphous regions, facilitating the ion transport easily. Additionally, future research could explore with other polymers such as poly (ethylene oxide) (PEO), poly (vinylidene fluoride) (PVDF) and poly(acrylonitrile) (PAN), and blending different high-quality nanofillers to achieve maximum conductivity, stability, and device performance.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eA.A. wrote and edited the manuscript. C.G. prepared the gel polymer electrolytes and wrote the main manuscript text. P.Q.B. prepared the gel polymer electrolytes. A.R.M. performed the X-ray diffraction measurements. N.M. analyzed the X-ray diffraction results. M.H. obtained the Fourier-transform infrared spectroscopy results. N. measured the electrochemical impedance spectroscopy results. I.M. analyzed the electrochemical impedance spectroscopy results. M.F. finalized the reference list. M.F. analyzed the Fourier-transform infrared spectroscopy results, edited the manuscript, and finalized it. All authors read and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eAuthors thanks Universiti Sains Malaysia, Bridging Grant with Project No: R501-LR-RND003-0000002095-0000\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eYang H, Wu N (2022) Ionic conductivity and ion transport mechanisms of solid-state lithium‐ion battery electrolytes: A review. Energy Sci Eng 10(5). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/ese3.1163\u003c/span\u003e\u003cspan address=\"10.1002/ese3.1163\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRayung M, Aung MM, Azhar SC, Abdullah LC, Su\u0026rsquo;ait MS, Ahmad A et al (2020) Bio-based polymer electrolytes for electrochemical devices: Insight into the ionic conductivity performance. Materials 13(4):838. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/ma13040838\u003c/span\u003e\u003cspan address=\"10.3390/ma13040838\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHan L, Wang L, Chen Z, Kan Y, Hu Y, Zhang H et al (2023) Incombustible polymer electrolyte boosting safety of solid-state lithium batteries: A review. Adv Funct Mater 33(32). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/adfm.202300892\u003c/span\u003e\u003cspan address=\"10.1002/adfm.202300892\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhmed MS, Islam M, Raut B, Yun S, Kim HY, Nam KW (2024) A comprehensive review of functional gel polymer electrolytes and applications in lithium-ion battery. Gels 10(9):563. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/gels10090563\u003c/span\u003e\u003cspan address=\"10.3390/gels10090563\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAruchamy K, Ramasundaram S, Divya S, Chandran M, Yun K, Oh TH (2023) Gel polymer electrolytes: Advancing solid-state batteries for high-performance applications. Gels 9(7):585. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/gels9070585\u003c/span\u003e\u003cspan address=\"10.3390/gels9070585\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAbubakar Abdulkadir B, Setiabudi HD (2025) Progress and accomplishments in polymer blend electrolytes for electrochemical energy storage: A comprehensive review. Polymer-Plastics Technol Mater 64(14):2143\u0026ndash;2178. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1080/25740881.2025.2511698\u003c/span\u003e\u003cspan address=\"10.1080/25740881.2025.2511698\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBehzadi Pour G, Nazarpour Fard H, Fekri Aval L (2024) A comparison of the electrical properties of gel polymer electrolyte-based supercapacitors: A review of advances in electrolyte materials. Gels 10(12):803. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/gels10120803\u003c/span\u003e\u003cspan address=\"10.3390/gels10120803\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRahim AA, Shamsuri NA, Adam AA, Aziz MF, Hamsan MH, Rusdi H et al (2024) Characterization of nanocomposite polyvinyl alcohol/cellulose acetate blend gel polymer electrolytes for supercapacitor application. J Energy Storage 97:112964. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.est.2024.112964\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2024.112964\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaut P, Kishnani V, Mondal K, Gupta A, Jana SC (2022) A Review on gel polymer electrolytes for dye-Sensitized solar cells. Micromachines 13(5):680. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/mi13050680\u003c/span\u003e\u003cspan address=\"10.3390/mi13050680\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAziz MF, Rahim AA, Rais ARM (2025) Unveiling ionic conductivity and ion transport properties in polyvinyl alcohol-based gel polymer electrolytes with quaternary ammonium iodide. J Polym Mater 42(4):1097\u0026ndash;1099. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.32604/jpm.2025.071129\u003c/span\u003e\u003cspan address=\"10.32604/jpm.2025.071129\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLing CK, Aung MM, Abdullah LC, Lim HN, Uyama H (2020) A short review of iodide salt usage and properties in dye sensitized solar cell application: Single vs binary salt system. Sol Energy 206:1033\u0026ndash;1038. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.solener.2020.06.055\u003c/span\u003e\u003cspan address=\"10.1016/j.solener.2020.06.055\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFarhana NK, Saidi NM, Bashir S, Ramesh S, Ramesh K (2021) Review on the revolution of polymer electrolytes for dye-sensitized solar cells. Energy Fuels 35(23):19320\u0026ndash;19350. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.energyfuels.1c03039\u003c/span\u003e\u003cspan address=\"10.1021/acs.energyfuels.1c03039\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLuo Y, Shi Z, Qiao S, Tong A, Liao X, Zhang T et al (2024) Advances in nanomaterials as exceptional fillers to reinforce carbon fiber-reinforced polymers composites and their emerging applications. Polym Compos 46(1):54\u0026ndash;80. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/pc.29027\u003c/span\u003e\u003cspan address=\"10.1002/pc.29027\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAl-Kelani M, Buthelezi N (2024) Advancements in medical research: Exploring Fourier transform infrared (FTIR) spectroscopy for tissue, cell, and hair sample analysis. Skin Res Technol 30(6). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1111/srt.13733\u003c/span\u003e\u003cspan address=\"10.1111/srt.13733\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSmith B (2016) The infrared spectroscopy of alkenes. Spectrosc Online. ;31(11)\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLin SY, Cheng WT, Wei YS, Lin HL (2011) DSC-FTIR microspectroscopy used to investigate the heat-induced intramolecular cyclic anhydride formation between Eudragit E and PVA copolymer. Polym J 43(6):577\u0026ndash;580. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1038/pj.2011.15\u003c/span\u003e\u003cspan address=\"10.1038/pj.2011.15\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFatimah S, Ragadhita R, Husaeni DFA, Nandiyanto ABD (2021) How to calculate crystallite size from x-ray diffraction (XRD) using Scherrer method. ASEAN J Sci Eng 2(1):65\u0026ndash;76. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.17509/ajse.v2i1.37647\u003c/span\u003e\u003cspan address=\"10.17509/ajse.v2i1.37647\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAziz MF, Rahim AA, Razak ESA, Jaaffar SNA, Buraidah MH, Shukur MF (2025) Enhanced ion transport and structural dynamics in gel polymer electrolytes containing a plasticizer prospect for DSSC application. Ionics 31(6):6103\u0026ndash;6115. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1007/s11581-025-06270-9\u003c/span\u003e\u003cspan address=\"10.1007/s11581-025-06270-9\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNoer Z, MN N, Bukit N, Juwairiah, Susilawati (2018) Ikhwanuddin. Characterization of low-density polyethylene (LDPE)/carbon black (CB) nanocomposite-based packaging material. Journal of Physics: Conference Series. ;1120(1):012066. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1088/1742-6596/1120/1/012066\u003c/span\u003e\u003cspan address=\"10.1088/1742-6596/1120/1/012066\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eUng\u0026aacute;r T, Gubicza J, Tichy G, Pantea C, Zerda TW (2004) Size and shape of crystallites and internal stresses in carbon blacks. Compos A Appl Sci Manuf 36(4):431\u0026ndash;436. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.compositesa.2004.10.017\u003c/span\u003e\u003cspan address=\"10.1016/j.compositesa.2004.10.017\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZhang S, Cui Y, Wu B, Song R, Song H, Zhou J et al (2013) Control of graphitization degree and defects of carbon blacks through ball-milling. RSC Adv 4(1):505\u0026ndash;509. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/c3ra44530e\u003c/span\u003e\u003cspan address=\"10.1039/c3ra44530e\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCattaruzza M, Fang Y, Istv\u0026aacute;n Fur\u0026oacute;, Lindbergh G, Liu F, Johansson M (2025) Hybrid polymer\u0026ndash;liquid lithium ion electrolytes: Effect of carbon black during polymerization-induced phase separation. Polymer 326:128341. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.polymer.2025.128341\u003c/span\u003e\u003cspan address=\"10.1016/j.polymer.2025.128341\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAlzahrani HAH (2022) CuO and MWCNTs nanoparticles filled PVA-PVP nanocomposites: Morphological, optical, dielectric, and electrical characteristics. IntechOpen eBooks 32(5). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.5772/intechopen.105810\u003c/span\u003e\u003cspan address=\"10.5772/intechopen.105810\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChen J, Liu B, Gao X, Xu D (2018) A review of the interfacial characteristics of polymer nanocomposites containing carbon nanotubes. RSC Adv 8(49):28048\u0026ndash;28085. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/c8ra04205e\u003c/span\u003e\u003cspan address=\"10.1039/c8ra04205e\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eTareen MHK, Hussain F, Zubair Z, Aslam S, Saleem T, Awais M et al (2022) Effects of carbon black on epoxidized natural rubber composites: Rheological, abrasion, and mechanical study. J Compos Mater 56(29):4473\u0026ndash;4485. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1177/00219983221134512\u003c/span\u003e\u003cspan address=\"10.1177/00219983221134512\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFredi G, Zimmerer C, Scheffler C, Pegoretti A (2020) Polydopamine-coated paraffin microcapsules as a multifunctional filler enhancing thermal and mechanical performance of a flexible epoxy resin. J Compos Sci 4(4):174. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/jcs4040174\u003c/span\u003e\u003cspan address=\"10.3390/jcs4040174\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eFang B, Wang T, Chen X, Jin T, Zhang R, Zhuang W (2015) Modeling vibrational spectra of ester carbonyl stretch in water and DMSO based on molecular dynamics simulation. J Phys Chem B 119(38):12390\u0026ndash;12396. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1021/acs.jpcb.5b06541\u003c/span\u003e\u003cspan address=\"10.1021/acs.jpcb.5b06541\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eChauhan APS, Chawla K (2016) Comparative studies on graphite and carbon black powders, and their dispersions. J Mol Liq 221:292\u0026ndash;297. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.molliq.2016.05.043\u003c/span\u003e\u003cspan address=\"10.1016/j.molliq.2016.05.043\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eManikandan KM, Arunagiri Yelilarasi, Saravanakumar SS, Althomali RH, Khan A, Abualnaja KM et al (2021) The effect of plasticizers on the polypyrrole-poly(vinyl alcohol)-based conducting polymer electrolyte and its application in semi-transparent dye-sensitized solar cells. Membranes 11(10):791. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/membranes11100791\u003c/span\u003e\u003cspan address=\"10.3390/membranes11100791\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBasha SKS, Sundari GS, Kumar KV (2016) Studies on electrical properties of potassium acetate complexed with polyvinyl alcohol for electrochemical cell applications. Materials Today: Proceedings. ;3(1):11\u0026ndash;20. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.matpr.2016.01.109\u003c/span\u003e\u003cspan address=\"10.1016/j.matpr.2016.01.109\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSong L, Sun S, Zhao X (2023) Ethylene carbonate plasticized polymer electrolyte for chloride ion batteries with enhanced reversible capacity. Solid State Ionics 399(116314):116314. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.ssi.2023.116314\u003c/span\u003e\u003cspan address=\"10.1016/j.ssi.2023.116314\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLiu Q, Zhao Y, Gao S, Yang X, Fan R, Zhi M et al (2021) Recent advances in the flame retardancy role of graphene and its derivatives in epoxy resin materials. Compos Part A: Appl Sci Manufac 149(106539):106539. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.compositesa.2021.106539\u003c/span\u003e\u003cspan address=\"10.1016/j.compositesa.2021.106539\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSmith BC (2022) The infrared spectra of polymers, VI: Polymers with C-O bonds. Spectroscopy 37(5):15\u0026ndash;19. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.56530/spectroscopy.ly3071f5\u003c/span\u003e\u003cspan address=\"10.56530/spectroscopy.ly3071f5\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePatel M, Mishra K, Chaudhary NA, Madhani V, Chaudhari JJ, Kumar D (2024) A sodium ion conducting gel polymer electrolyte with counterbalance between 1-ethyl-3-methylimidazolium tetrafluoroborate and tetra ethylene glycol dimethyl ether for electrochemical applications. RSC Adv 14(20):14358\u0026ndash;14373. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1039/d4ra01615g\u003c/span\u003e\u003cspan address=\"10.1039/d4ra01615g\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAziz S, Abdullah R, Rasheed M, Ahmed H (2017) Role of ion dissociation on DC conductivity and silver nanoparticle formation in PVA:AgNt based polymer electrolytes: Deep insights to ion transport mechanism. Polymers 9(12):338. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/polym9080338\u003c/span\u003e\u003cspan address=\"10.3390/polym9080338\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNegi SS, Rawat S, Singh PK, Pandey SP, Yadav T, Srivastava M et al (2024) Influence of carbon black on conductivity and structure of polyethylene oxide based polymer electrolyte film. Macromolecular Symposia 413(1):2300104. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/masy.202300104\u003c/span\u003e\u003cspan address=\"10.1002/masy.202300104\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNegi SS, Rawat S, Singh PK, Savilov SV, Yadav T, Yahya MZA et al (2024) Conducting carbon black nano-filler doped polymer electrolyte for electrochemical application. ChemistrySelect 9(25). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1002/slct.202400847\u003c/span\u003e\u003cspan address=\"10.1002/slct.202400847\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eShamsuri NA, Halim SNA, Aziz SB, Abdulwahid RT, Alias Y, Kadir MFZ (2024) Bio-derived gel polymer electrolytes from zein and honey blends integrated with ammonium nitrate for electrical double layer capacitors. J Energy Storage 102:113909. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.est.2024.113909\u003c/span\u003e\u003cspan address=\"10.1016/j.est.2024.113909\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMohan K, Swapnil Dolui, Nath BC, Bora A, Sharma S (2017) Swapan Kumar Dolui. A highly stable and efficient quasi solid-state dye sensitized solar cell based on polymethyl methacrylate (PMMA)/carbon black (CB) polymer gel electrolyte with improved open circuit voltage. Electrochim Acta 247:216\u0026ndash;228. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.electacta.2017.06.062\u003c/span\u003e\u003cspan address=\"10.1016/j.electacta.2017.06.062\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eBarzegar F, Dangbegnon JK, Bello A, Momodu DY, Johnson AT, Manyala N (2015) Effect of conductive additives to gel electrolytes on activated carbon-based supercapacitors. AIP Adv 5(9). \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1063/1.4931956\u003c/span\u003e\u003cspan address=\"10.1063/1.4931956\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRaut P, Kishnani V, Mondal K, Gupta A, Jana SC (2022) A review on gel polymer electrolytes for dye-sensitized solar cells. Micromachines 13(5):680. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.3390/mi13050680\u003c/span\u003e\u003cspan address=\"10.3390/mi13050680\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKhan Z, Ail U, Ajjan FN, Phopase J, Kim N, Kumar D et al (2022) Towards printable water-in-polymer salt electrolytes for high power organic batteries. J Power Sources 524:231103. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003e10.1016/j.jpowsour.2022.231103\u003c/span\u003e\u003cspan address=\"10.1016/j.jpowsour.2022.231103\" 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":false,"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":"Gel polymer electrolyte, Polyvinyl alcohol, Carbon black, Ionic conductivity, Electrochemical properties","lastPublishedDoi":"10.21203/rs.3.rs-8952004/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8952004/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eA safer and more stable gel polymer electrolytes (GPEs) have gained attention as potential alternatives to liquid electrolytes in electrochemical systems. However, their performance is limited by their high polymer crystallinity and low ionic conductivity. In this study, a series of polyvinyl alcohol (PVA)-based GPEs system were synthesized using potassium iodide (KI) salt in ethylene carbonate (EC), propylene carbonate (PC), and dimethyl sulfoxide (DMSO) solvent. Various concentrations of carbon black (CB) nanofillers were added in electrolytes to study the effect of nanofiller on electrolyte characteristics. The structural and electrochemical properties of the GPEs was systematically investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and electrochemical impedance spectroscopy (EIS). XRD results confirmed a reduction in crystallinity with increasing CB content, while FTIR analysis indicated strong interactions between CB and the polymer matrix. A notable enhancement in ionic conductivity achieved a maximum value of 11.80 mS cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with addition of 12 wt.% of CB, indicating improved ion transport pathways. The findings demonstrate that carbon black plays a critical role in tailoring the physical and electrochemical characteristics of PVA-based GPEs, offering promising potential for advanced electrochemical applications.\u003c/p\u003e","manuscriptTitle":"Carbon Black-Modified Polyvinyl Alcohol-Based Gel Polymer Electrolytes with Enhanced Ionic Conductivity","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-06 13:06:13","doi":"10.21203/rs.3.rs-8952004/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-31T19:02:20+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-24T11:33:47+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-17T05:51:32+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-15T03:52:25+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"199852839023123670938894486285691269887","date":"2026-03-09T04:11:33+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"49939413858200205931151341620945995079","date":"2026-03-05T13:46:00+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-04T05:25:11+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"288884571165415311145968871402220680071","date":"2026-03-04T01:00:10+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"21944591662612820526411118474868782231","date":"2026-03-03T14:38:55+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"112572184720945613394807950031234550655","date":"2026-03-03T12:44:18+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"140771522838209058184767747620343214363","date":"2026-03-03T12:33:55+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-03T12:25:41+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-03T00:17:58+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-03T00:17:29+00:00","index":"","fulltext":""},{"type":"submitted","content":"Ionics","date":"2026-02-24T02:55:58+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":"1e137ac3-d2be-4ad4-8a63-5f6cc18b10c0","owner":[],"postedDate":"March 6th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-05-14T12:38:43+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-06 13:06:13","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8952004","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8952004","identity":"rs-8952004","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}