A Cyclic Voltammetry study of a gel polymer electrolyte based redox-capacitor

Abstract

This work describes the performance of a gel polymer electrolyte (GPE) based redox capacitor using the cyclic voltammetry technique.GPE was prepared with 22.5 wt% polyacrylonitrile (PAN), (1:1weight ratio) ethylene carbonate (EC) and propylene carbonate (PC) having a salt concentration of 1.0 M sodium iodide (NaI). Dependence of ionic conductivity of GPE on temperature was investigated using ac impedance spectroscopy. Two polypyrrole (PPy) electrodes were used as the electrodes of the redox capacitor. The performance of the device was evaluated by cyclic voltammetry. The redox-capacitors were cycled at different scan rates to determine the scan rate at which the maximum capacitance is obtained. After tracking that scan rate, continuous cycling was carried out at that scan rate to investigate the deterioration of capacitance upon cycling. The room temperature conductivity (σ) of the GPE was 4.29 × 10-3 S cm-1. The conductivity variation with temperature followed the Arrhenius behavior. From the scan rates selected for the study, the maximum capacity could be obtained at the scan rate of 30 mV s-1. The average specific capacity of the redox capacitor was 26.70 Fg-1 .