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.