Engineering Sustainable Chitosan–PVA Solid Polymer Electrolytes with Enhanced Ionic Transport for Next-Generation Energy Storage Devices

FIRDOS JAHANa ,R D MATHADb

Department of Post Graduate Studies and Research in Physics, Gulbarga University, Kalaburgi, India

Abstract

The increasing demand for sustainable energy storage technologies has intensified the search for biodegradable solid polymer electrolytes capable of replacing conventional petroleum-based materials. Chitosan has emerged as a promising biopolymer owing to its biodegradability, biocompatibility, non-toxicity, and excellent film-forming ability; however, its relatively low ionic conductivity and limited mechanical strength restrict its practical application in advanced electrochemical devices. This study presents the development of an eco-friendly chitosan–polyvinyl alcohol (PVA) solid polymer electrolyte through a solution-casting technique, followed by ionic crosslinking using potassium nitrate (KNO₃) to enhance structural stability and ion transport characteristics. The incorporation of PVA improves the flexibility and uniformity of the polymer matrix, while KNO₃ facilitates the generation of mobile charge carriers and promotes efficient ionic migration. The synthesized polymer electrolyte films were systematically characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS), and dielectric analysis to investigate their structural, morphological, and electrochemical properties. The experimental results reveal that ionic crosslinking suppresses the crystalline phase, increases the amorphous content, and enhances ionic mobility, resulting in improved ionic conductivity and dielectric performance across a broad frequency range. The enhanced electrochemical characteristics demonstrate the effectiveness of the proposed polymer architecture in facilitating charge transport while maintaining environmental sustainability. The developed chitosan–PVA polymer electrolyte exhibits significant potential for application in solid-state batteries, supercapacitors, fuel cells, and flexible electronic systems. This work establishes a sustainable materials engineering approach for designing high-performance biodegradable polymer electrolytes and provides a promising pathway toward the development of environmentally responsible electrochemical energy storage technologies.

Keywords: Chitosan, Polyvinyl Alcohol, Solid Polymer Electrolyte, Ionic Conductivity, Potassium Nitrate, Electrochemical Devices, Sustainable Energy Storage, Biopolymer.