Pastes and hydrogels from carboxymethyl cellulose sodium salt as supporting electrolyte of solid electrochemical supercapacitors

摘要

Different carboxymethyl cellulose sodium salt (NaCMC)-based pastes and hydrogels, both containing a salt as supporting electrolyte, have been prepared and characterized as potential solid state electrolyte (SSE) for solid electrochemical supercapacitors (ESCs).The characteristics of the NaCMC-based SSEs have been optimized by examining the influence of five different factors in the capacitive response of poly(3,4-ethylenedioxythiophene) (PEDOT) electrodes:i)the chemical nature of the salt used as supporting electrolyte;ii)the concentration of such saiii)the concentration of cellulose used to prepare the paste;iv)the concentration of citric acid employed during NaCMC cross-linking; andv)the treatment applied to recover the supporting electrolyte after washing the hydrogel. The specific capacitance of the device prepared using the optimized hydrogel as SSE is 81.5 and 76.8?F/g by means of cyclic voltammetry and galvanostatic charge/discharge, respectively, these values decreasing to 60.7 and 75.5?F/g when the SSE is the paste.