Effects of temperatures and cations of electrolyte on the capacitive characteristics of the manganese oxide deposited by hydrothermal electrochemical method

A nanoscale hydrous manganese oxide used as an electrode in a supercapacitor was deposited onto a titanium substrate from an aqueous manganese acetate solution using the hydrothermal electrochemical method. The effect of deposition temperature on the characteristics of the manganese oxides was investigated. The capacitive characteristics of the manganese oxides were measured in sulfate electrolytes with various cations using cyclic voltammetry. The capacitive performances of the manganese oxide electrodes depend on the deposition temperature as well as the cations of electrolytes. A maximum capacitance of 244 F g−1 was obtained in Na2SO4 solution. The stability of manganese oxide was examined; after 1000 cycles, 80% of the initial capacitance remained.