Conductivity and electrochemical behaviour of CoFe2O4 dispersed potato starch-based solid biopolymer electrolyte for energy application.

Solid biopolymer electrolytes based on potato starch (PS), sodium iodide (NaI), and dispersed with cobalt ferrite (CoFe₂O₄) as ceramic nanofillers were synthesized via a solution casting technique. These synthesized solid biopolymer electrolytes have been characterized by electrical impedance spectroscopy (EIS), Fourier transform infrared (FTIR) spectroscopy, FTIR deconvolution technique, dielectric studies, linear sweep voltammetry (LSV), and cyclic voltammetry (CV). The highest conductivity is found to be 8.13 × 10^–3 S/cm for the system containing 1.0 wt.% of CoFe₂O₄ nanofillers. The ceramic nanofillers enhance the ion motion inside the polymer matrix, leads to increase the electrolyte's conductivity. FTIR confirmed that the polymer, NaI salt, and ceramic nanofiller interact with each other appreciably, and formed the complexation between the polymer, NaI salt, and ceramic nanofillers. The ion transport parameters such as mobility (µ), carrier density (n), and diffusion coefficient (D) were determined from the deconvolution of FTIR spectra and further used to compute the free ions and contact ion pairs in the solid biopolymer electrolytes. LSV and CV measurements indicate that the synthesized solid biopolymer electrolytes have a great potential in the electrochemical devices. The electrochemical stability window of the material (PNGC-1.0) is 2.5 V, and CV measurement shows the absence of any redox peaks, which may be a promising electrolyte for supercapacitor applications. [ABSTRACT FROM AUTHOR]