Manganese oxide was obtained by cathodic electrochemical deposition from the electrolyte solutions adding sodium nitrate or sulfate. The structural characteristics and the elemental composition of the MnO2 samples were studied by energy dispersive microanalysis, IR spectroscopy, and transmission electron microscopy. The electrochemical characteristics of the electrodes were determined by cyclic voltammetry, galvanostatic charge-discharge and impedance spectroscopy in 0.5M Na2SO4 solution.
