Anodic deposition of porous RuO2 on stainless steel for supercapacitor studies at high current densities

Ruthenium dioxide is deposited on stainless steel (SS) substrate by galvanostatic oxidation of Ru3+. At high current densities employed for this purpose, there is oxidation of water to oxygen, which occurs in parallel with Ru3+ oxidation. The oxygen evolution consumes a major portion of the charge. The oxygen evolution generates a high porosity to RuO2 films, which is evident from scanning electron microscopy studies. RuO2 is identified by X-ray photoelectron spectroscopy. Cyclic voltammetry and galvanostatic charge-discharge cycling studies indicate that RUO2/SS electrodes possess good capacitance properties. Specific capacitance of 276 F g(-1) is obtained at current densities as high as 20 mA cm(-2) ( 13.33 A g(-1)). Porous nature of RuO2 facilitates passing of high currents during charge-discharge cycling. RuO2/SS electrodes are thus useful for high power supercapacitor applications. (c) 2007 Elsevier B.V. All rights reserved.