Performance of Electric Double-Layer Capacitor with Acidic Cellulose-Chitin Hybrid Gel Electrolyte

An acidic cellulose-chitin hybrid gel electrolyte is prepared from cellulose, chitin, binary ionic liquids, and an aqueous H(2)SO(4) solution for an electric double-layer capacitor (EDLC). The obtained acidic hybrid gel shows a high ionic conductivity of 57.8 S m(-1) at a room temperature of 25 degrees C, which is comparable to 61.9 S m(-1) of an aqueous 2 mol dm(-3) H(2)SO(4) electrolyte. The acidic cellulose-chitin hybrid gel electrolyte is applied to an EDLC cell with activated carbon fiber cloths as polarizable electrodes, and its electrochemical performance is investigated by galvanostatic cycling, cyclic voltammetry, and a self-discharge test. The EDLC cell with the acidic cellulose-chitin hybrid gel electrolyte exhibits a higher capacitance and a better cycle life than cells with the reference aqueous H(2)SO(4) electrolyte. The self-discharge measurement suggests that leakage current and potential decay are suppressed by the application of the acidic cellulose-chitin hybrid gel electrolyte. These results indicate that the acidic cellulose-chitin hybrid gel electrolyte has a practical applicability to an advanced EDLC with excellent stability and working performance.