Capacitance Enhancement of Activated Carbon Fiber Cloth Electrodes in Electrochemical Capacitors with a Mixed Aqueous Solution of H[sub 2]SO[sub 4] and AgNO[sub 3]

Properties of the electrochemical capacitors composed of activated carbon fiber cloth (ACFC) electrodes and a mixed aqueous solution of and have been investigated. The specific capacitance of the capacitors increased with increasing the concentration of in the mixed solution. The maximum specific capacitance of (capacitance∕mass of total ACFC in the capacitor) was achieved in this study, an increase of about 300%. In the cyclic voltammograms of the ACFC in the mixed solution of and , redox peaks were observed obviously. The enhancement of the capacitance of the capacitors with the mixed solution is due to the pseudocapacitance associated with the redox reaction of redox couple.