Manganese oxide film electrodes prepared by electrostatic spray deposition for electrochemical capacitors from the KMnO4 solution

Manganese oxide film electrodes for electrochemical capacitors were deposited on the polished Pt foils by electrostatic spray deposition (ESD) from KMnO4 precursor solution. The electrochemical properties of electrodes were systematically studied using cyclic voltammetry (CV), constant current charge–discharge tests, and electrochemical impedance spectroscopy (EIS). The specific capacitance (SC) of thick deposited film was 149 F g−1 at the very high scan rate of 500 mV s−1, in comparison with 209 F g−1 at the low scan rate of 5 mV s−1. The electrode shows good cyclic performance. The initial SC value was 163 F g−1 and 103% of the initial SC can be retained after 10,000 cycles at the scan rate of 50 mV s−1.