Impedance, FTIR and transport properties of plasticized proton conducting biopolymer electrolyte based on chitosan for electrochemical device application

Abstract

Biodegradable polymer-based electrolyteswere synthesized through a solution casting technique. Chitosan (CS) as host polymer was plasticized with varying quantities of glycerol after being integrated with 40% ammonium thiocyanate (NH4SCN). The electrochemical behavior of the prepared sampleswas investigated throughelectrochemicalimpedance spectroscopy (EIS). Each of linear sweep voltammetry (LSV) and transference number measurement (TNM) technique were employed to determine the polymer electrolyte’s potential stability and main charger carrier transport. The performance of the fabricated electrical double layer capacitor (EDLC) was analyzed using cyclic voltammetry (CV). Essential parameters, such as specific capacitance (Cs), equivalent series resistance (ESR), efficiency, energy density (Ed), and power (Pd) density, were determined.It has been discovered that adding glycerol as a plasticizer can improve ionic conductivity and its capacitance behavior. Electrical impedance spectroscopy (EIS) was used to evaluate the direct current electrical conductivity of the films, and the electrolyte with the highest glycerol inclusion had the highest ionic conductivity of (8.57 × 10-4 S/cm). Fourier transformed infrared (FTIR) spectroscopy has been used to investigate the compatibility of CS with the electrolyte components. The degree of interactions was demonstrated by the shift and change in the intensity of the FTIR peaks. The breakdown voltage of the polymer electrolyte was identified to be 2.09 V. It was computed and discovered that the ionic transference number (tion) is 0.956, verifying the dominancy of ionic conduction in the electrolyte system. To examine theassembled EDLC, the specific capacitance (Cs) was evaluated and determined as 41.11F/g at the scan rates of 50 mV/swithits initial (Ed) and (Pd) values of 15.56 Whkg−1 and 750 Wkg−1, respectively.