Charge-Discharge Behavior of Electric Double Layer Capacitor with Acidic Cellulose-Chitin Hybrid Gel Electrolyte

Abstract

A novel acidic cellulose-chitin hybrid gel electrolyte including binary ionic liquids (ILs) with an aqueous H2SO4 solution was prepared for an electric double layer capacitor (EDLC). Its electrochemical characteristics were investigated by galvanostatic charge-discharge measurements. The cell with the hybrid gel containing binary ILs and H2SO4 has higher capacitance than that containing only the aqueous H2SO4 solution. This hybrid gel electrolyte exhibits excellent high-rate discharge capability in a wide range of current densities as well as an aqueous H2SO4 solution. The discharge capacitance of the test cell can retain over 80% of its initial value in 100,000 cycles even at a high current density of 5,000 mA g-1.