Dependence on the electrolyte solution of the capacitance of active carbon fiber electrode for electric double layer capacitor

Double layer capacitance of phenoric-resin based active carbon fiber (ACF) electrode was enhanced by a method of electrochemical treatment in various acidic electrolytes. Oxidic acids, especially perchloric acid solution, showed higher enhancement of the ACF capacitance by the electrochemical treatment. Thus, the capacitor was constructed with using 1.0 mol dm^-3 HClO₄ electrolyte solution and ACF electrode oxidized at 1.0 V vs. SCE for 1 h. The capacitor gives charging-discharging characteristics better than that of H₂SO₄ electrolyte system.