Development and Property Evaluation of Sustainable Solid Polymer Electrolyte Based on Chitosan, Polyvinyl Alcohol and Polyvinyl Pyrolidone Blend Doped With <scp> NaNO ₃ </scp>

ABSTRACT Solid polymer electrolytes (SPEs) have emerged as a transformative alternative to conventional liquid electrolytes in battery systems, offering enhanced safety, efficiency, and flexibility. These electrolytes are revolutionizing battery technology by enabling lightweight, leak‐proof, and thermally stable energy storage systems, making them ideal for modern portable wearable electronic applications. In this study, sodium‐ion‐conducting SPEs were developed using a blend of chitosan (CS), polyvinyl pyrrolidone (PVP), and polyvinyl alcohol (PVA), synthesized using the solution‐casting technique. Sodium nitrate (NaNO 3 ) was incorporated as a dopant at various concentrations (10–40 wt%). The prepared films were characterized in terms of their structural, morphological, and electrical properties. FTIR and XRD analyses confirmed the successful incorporation of the ionic species into the polymeric matrix. The film with 40 wt% sodium nitrate had the highest ionic conductivity of 1.1 × 10 −4 ± 0.109 S/cm, with the proportions of free ions, contact ions, and ion aggregates as 48%, 34%, and 17%, respectively. Dielectric studies further validated the influence of molecular polarization and confirmed the enhanced dielectric response in the film with 40% NaNO 3 . Surface morphology analysis using SEM revealed the uniform dispersion of NaNO 3 , which positively influenced ion mobility and conductivity. The optimized film with 40 wt% sodium nitrate demonstrated better thermal stability up to 550°C and good ionic conductivity comparable to existing solid polymer electrolytes reported in the literature. Hence, this work will be a promising focus for next‐generation materials in the field of energy storage systems.