Supercapacitive studies on IrO2 thin film electrodes prepared by radio frequency magnetron sputtering

IrO2 thin films were prepared by radio frequency magnetron sputtering technique at different substrate temperatures. Supercapacitive properties of the films were studied by cyclic voltammetry and electrochemical impedance spectroscopy in 1 M LiNO3 electrolyte for the first time. The specific capacitance of the single IrO2 film electrode was calculated to be 293 F g(-1) at a scan rate of 5 mV s(-1) for the sample prepared at room temperature. After 1000 cycles, the specific capacitance of IrO2 electrode decreases slightly, indicating the sputtered IrO2 thin-film electrode has excellent cycling performance in aqueous LiNO3 electrolyte. (C) 2008 The Electrochemical Society.