▎ 摘　　要

MnO2/graphene composite was synthesized by a facile and effective polymer-assisted chemical reduction method. The nanosized MnO2 particles were homogeneously distributed on graphene nanosheets, which have been confirmed by scanning electron microscopy and transmission electron microscopy analysis. The capacitive properties of the MnO2/graphene composite have been investigated by cyclic voltammetry(CV). MnO2/graphene composite exhibited a high specific capacitance of 324 F g(-1) in 1 M Na2SO4 electrolyte. In addition, the MnO2/graphene composite electrode shows excellent long-term cycle stability (only 3.2% decrease of the specific capacitance is observed after 1,000 CV cycles).