Electrochemical capacitors have attracted great interest because they can maintain high power density along with high energy density. In this study, manganese oxides were electrodeposited onto nickel mesh substrate under hydrothermal conditions to be used as electrodes for electrochemical capacitors. Obtained Mn3O4 (hausmannite) phase was electrochemically oxidized to mixed-valent MnO2 during potential cycling. MnO2 electrodes showed excellent pseudocapacitative behaviour in cyclic voltammetry (CV) and charge-discharge (CD) measurements. Produced electrodes had specific capacitance of 518.8Fg−1 at 0.1mAcm−2. Also, the electrodes maintained their capacitative properties at high scan rates/current densities and after 10,000 cycles of CV measurement.