Preparation and performance of MnO₂/graphene composite electrode materials

In this paper, graphene is synthesized from natural graphite by a modified Hummers method and glucose is added as reducing agent. Hydrothermal method is used to prepare MnO2/graphene composite using KMnO4 and HCl as raw materials. The structure is characterized by SEM and XRD. The result shows that MnO2 prepared by hydrothermal method is pure -MnO2, and the addition of graphene powder doesnt influence its crystal structure. Electrochemical characterization is performed using cyclic voltammetry and chronopotentiometry in 1 mol/L Na2SO4 aqueous solution electrolyte. The electrode has a stable electrochemistry performance, and preferable reversibility, the specific capacitance of MnO2/graphene electrode is 147.9 F/g under 1.27 mA/cm2 current densities. The electrode presents a stable capacitiance after 1000 cycles and it is an ideal electrochemical material.