Compatible solid polymer electrolyte based on methyl cellulose for energy storage application: Structural, electrical, and electrochemical properties

Abstract

Compatible Green polymer electrolytes based on methyl cellulose (MC) have been prepared for energy storage electrochemical double-layer capacitor (EDLC) application. X-ray diffraction was accomplished for structural investigation. The reduction of intensity of crystalline peaks of MC upon addition of sodium iodide (NaI) salt discloses the growth of amorphous area in SPEs. Impedance plots displays that the uppermost conducting electrolyte has a lesser bulk resistance. The highest attained DC conductivity is ( ) S/cm for the sample integrated with 50 wt.% of NaI. The dielectric analysis suggests that samples in this study show non-Debye behavior. The electron transference number is found to be lower than the ion transference number, thus it can be concluded that ions are the primary charge carriers in MC-NaI system. The addition of relatively high concentration of salt into MC matrix changing the ion transfer number from 0.75 to 0.93. From linear sweep voltammetry (LSV), green polymer electrolyte in this work is actually stable up to 1.7 V. The consequence of cyclic voltammetry (CV) plot suggests that the nature of charge storage at the electrode-electrolyte interfaces is a non-Faradaic process and specific capacitance is subjective by scan rates. The relatively high capacitance of 94.7 F/g at a sweep rate of 10 mV/s was achieved for EDLC assembly containing a MC-NaI system.