Dip-coated Ru-V oxide electrodes for electrochemical capacitors

RuO2-VOx electrodes prepared by a dip-coating method provide a large electrochemically active surface area. A RuO2(33%)-VOx(67%)/Ti electrode calcined at 450 degrees C gave the highest value of voltammetric charge, about 50 times larger as that of a RuO2/Ti electrode. The large electrochemically active surface areas of the RuO2-VOx/Ti electrodes were characterized by a dispersion of fine V2O5 particles as well as the formation of the ruthenium vanadium double oxide, Ru2VO6, while the presence of ultrafine RuO2 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 s(-1) sweep rate corresponds to 0.76 protons contributed to the adsorption on every ruthenium ion loaded on a titanium substrate.