Layers of cobalt and manganese oxides were codeposited or deposited on top of each other or next to each other by potentiostatic method onto stainless steel substrate. Deposition potentials of 1 and −1 V for the anodic and cathodic depositions were employed. Specific capacitance values in the range of 38.5-78 F g −1 were found with cobalt oxide on top of manganese oxide having the lowest and manganese oxide on top of cobalt oxide having the highest capacitances. The usefulness of the electrodes was characterized by cyclic voltammetry, charge-discharge cycling, and electrochemical impedance spectroscopy in 2 M NaOH electrolyte for redox supercapacitor applications. The latter presented the best charge/discharge behavior with no voltage drop due to lower ohmic resistance in prepared substrate; although the steadiest current observed in the course of voltammetry was due to the former. The evaluated double layer and specific capacitances for codeposited sample according to the impedance studies were 1.75 and 47.5 F g −1 , respectively, being in good agreement with voltammetric measurements.

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:A porous nickel (P-Ni) substrate was prepared by selective leaching of zinc from pressed pellets containing powders of Ni & Zn in 4 M NaOH solution. Anodic deposition of manganese oxide onto the porous Ni substrate (MnO x /P-Ni) formed nano-flakes of manganese oxide layers as revealed in SEM studies. Pseudocapacitance of this oxide electrode was evaluated by cyclic voltammetry (CV) and chronopotentiometry (CHP) in 2 M NaOH solution. The specific capacitance of the Mn oxide electrode was as high as 1515 F g −1 , which was ten times higher than Mn oxide deposited on a flat Ni-ribbon. 80% of capacity was retained after 200 charge/discharge cycles. The system showed no loss of activity in dry form over period of days. The impedance studies indicated highly conducting MnO x /P-Ni substance and the obtained specific capacitance from impedance data showed good agreement with the charge/discharge measurements.