An acidic cellulose-chitin hybrid gel as novel electrolyte for an electric double layer capacitor

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 test cell with a hybrid gel electrolyte shows a specific capacitance of 162 F g(-1) at room temperature, which is higher than that for a cell with an H2SO4 electrolyte, 155 F g(-1). 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 5000 mA g(-1). (C) 2008 Elsevier B.V. All rights reserved.