Manganese oxide thin films prepared by potentiodynamic electrodeposition and their supercapacitor performance

Manganese oxide film for supercapacitor applications was prepared by potentiodynamic electrodeposition in a manganese acetate plating solution. The effects of the potential sweep rate on the oxide microstructure, crystallinity, and chemical states were examined using a scanning electron microscope, an X-ray diffractometer, and an X-ray photoelectron spectrometer, respectively. Electrochemical performance of the film electrodes was evaluated using a cyclic voltammetric measurement. The experimental results indicate that the deposition potential sweep rate significantly affected the material properties of the prepared oxide films. The oxide-specific capacitance increased from 262 to 337 F/g when the sweep rate was increased from 100 to 400 mV/s. The key material factors that govern the specific capacitance and cyclic stability of the oxide electrodes were discussed.