Electrochemical Properties of RuO2 Electrodes as a Function of Thin Film Thickness

A thin film RuO2 electrode was prepared by spin coating thermal decomposition methods. Precursor containing RuCl3 center dot nH(2)O and isopropyl alcohol was coated on tantalum substrate and annealed at 250-260A degrees C for 3 h to form a thin film RuO2 electrode of about 2.5 mu m, 5.6 mu m, 11.4 mu m, and 14.5 mu m in thickness. X-ray diffraction revealed that peak intensities of those electrodes were similar and close to each other. Scanning electron microscopy showed that thin film of 5.6 mu m in thickness was dense and free of cracks. Electrochemical performances of electrodes were examined by cyclic voltammetry, galvanostatic charge/discharge as well as equivalent series resistance. The highest specific capacitance value of 725 F g(-1) was registered for the electrode of 5.6 mu m in thickness with good constant current charge/discharge and equivalent series resistance of 0.36 Omega as well as cyclic stability.