Effect of glycerol on EDLC characteristics of chitosan:methylcellulose polymer blend electrolytes

Abstract

Chitosan (CS):methylcellulose (MC):NH4I based solid polymer electrolyte (SPE) has been plasticized using glycerol due to its hydroxyl-rich structure. All SPEs are prepared using solution cast technique at room temperature. Prior to device application, structural, electrical and electrochemical characteristics were examined for the prepared samples using various techniques. X-ray diffraction (XRD) investigation was used to explain the structural changes. Electrical impedance spectroscopy (EIS) was used to evaluate the DC conductivity. The potential stability of the highest conducting film (6.65 × 10−4 S cm−1) was found to be 2.2 V as well as shows the characteristic of an ionic conductor where tion > te. The layers of the electrical double-layer capacitor (EDLC) consist of two identical activated carbon electrodes sandwiching the highest conducting SPE. The existence of charge double-layer in the fabricated EDLC has been verified using cyclic voltammetry test. From galvanostatic charge–discharge measurements, several crucial EDLC parameters have been obtained, e.g. specific capacitance, internal resistance, energy density and power density. The addition of glycerol improved the performance of the EDLC.

Keywords

• Polymer blend electrolyte
• Glycerol plasticizer
• Natural polymers
• Impedance spectroscopy
• XRD analysis
• EDLC study