Abstract: The nanophase MnO2 was synthesized by solid-phase reaction as electrode material for electrochemical supercapacitor and the MnO2 electrode was tested by cyclic voltammetry(CV),electrochemical impedance spectrometry (EIS) and constant charge-discharge curves. The result shows that MnO2 electrode has good performance of faradic pseudocapacitance in 1mol•L－1 KOH between －0.1 and 0.6 V(vs Hg/HgO). The electrode can provide a specific capacitance of 240.25 to 325.21 F•g－1 at different current densities. After 5000 cycles of constant charge-discharge the capacitance reduces no more than 10％.

Key words: Supercapacitor, MnO₂ electrode, Electrode material, Specific capacitance, Cycle life