Analyzing Ionic Transport Properties of Starch/Glycerin-Sodium Phosphate Solid Polymer Electrolyte Utilizing Electrochemical Impedance Spectroscopy

Abstract

Thin films of solid polymer electrolytes are being fabricated using corn starch doped with glycerin/sodium phosphate and varying ratios of polymer and salt. These films are prepared through a dual-solvent technique. Glycerin is introduced into the solution mixture to enhance the elasticity of the polymer film, thereby increasing the flexibility of the thin membrane. The conductivity and electrical properties of these thin films are being analyzed to gain insights into the ion transport characteristics of the polymer electrolytes. At room temperature, the highest observed conductivity is 1.22 × 10⁻² S cm⁻¹, achieved in the 30 wt.% Na₃PO₄ salt-doped polymer electrolyte system. Upon evaluating the transport properties, it becomes evident that the ionic conductivity is predominantly influenced by the concentration of charge carriers, especially in high Na₃PO₄ content. As the salt content is further increased, the diffusion coefficient and mobility of charge carriers decrease.