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

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.