Dip‐Coated Ru‐V Oxide Electrodes for Electrochemical Capacitors

Abstract

RuO2-VO electrodes prepared by a dip-coating method provide a large electrochemically active surface area. A RuO2(33%)-VO(67%)/Ti electrode calcined at 450°C gave the highest value of voltammetric charge, about 50 times larg-er as that of a Ru02/Ti electrode. The large electrochemically active surface areas of the RuO2-VO/Ti electrodes were characterized by a dispersion of fine V205 particles as well as the formation of the ruthenium vanadium double oxide, Ru3VO9, while the presence of ultrafine Ru02 particles cannot be ruled out. The electric charge capacity of the electrode between 0.3 and 1.1 V (vs. RHE) at a 50 mV sweep rate corresponds to 0.76 protons contributed to the adsorption on every ruthenium ion loaded on a titanium substrate. Infroduction Electrochemical capacitors have been considered in conjunction with batteries for high power applications not only in electric vehicle technology, but also for internal combustion engine cars. A number of materials have been examined including active carbons, conducting polymers, and metal oxides in combination with aqueous or organic