Preparation and electrochemical characteristics of manganese dioxide/graphite nanoplatelet composites

MnO2/graphite nanoplatelet (GNP) composites were prepared by hydrothermal synthesis. Their morphology and microstructure were examined by scanning electron microscopy and X-ray diffraction. Electrochemical studies indicate that the composites have excellent electrochemical properties due to the homogeneous dispersion of MnO2 nanorods on both surfaces of the GNPs with a coated structure. The maximum specific capacitance of MnO2/GNPs (based on MnO2) is 276.3 F g−1. Such coating structure also decreases the amount of conductive filler needed to meet the requirement of an electrode material. The specific capacitance based on the composite is 158 F g−1 by addition of only 10 wt% GNPs. The effects of microstructure of MnO2/GNPs composites and the amount of GNPs on the electrochemical properties are also discussed.