Abstract: MnO2/graphene composites were synthesized by hydrothermal method. The surface morphology of the material was analyzed by scanning electron microscope ( SEM ) . The crystal phase structure and composition of the materials were characterized by X-ray diffraction ( XRD ) and X-ray photoelectron spectroscopy ( XPS ) . The electrical properties of LiSi/LiCl-KCl/ ( MnO2/G ) cell were tested by the method of constant current discharge. The test results show that adding of GO into the reaction system made the material is composed of nano-ball type and a large number of irregular nanorods structure woven together, and the α-MnO2 nanoclusters structure attach to graphene nanosheets. The disorder wide diffraction peaks of product during 2θ of 22°-27° is graphene. After oxidation of Mn element, the ion state of the Mn element is changed into Mn4+. The LiSi/LiCl-KCl/ ( MnO2/G) cell has two discharge platforms for 2. 58 V and 1. 96 V, respectively, when discharge voltage cut-off to 1. 0 V, the corresponding discharge specific capacity reach 1150. 2 mAh/g.

Key words: MnO2/graphene composites were synthesized by hydrothermal method. The surface morphology of the material was analyzed by scanning electron microscope ( SEM ) . The crystal phase structure and composition of the materials were characterized by X-ray diffraction ( XRD ) and X-ray photoelectron spectroscopy ( XPS ) . The electrical properties of LiSi/LiCl-KCl/ ( MnO2/G ) cell were tested by the method of constant current discharge. The test results show that adding of GO into the reaction system made the material is composed of nano-ball type and a large number of irregular nanorods structure woven together, and the α-MnO2 nanoclusters structure attach to graphene nanosheets. The disorder wide diffraction peaks of product during 2θ of 22°-27° is graphene. After oxidation of Mn element, the ion state of the Mn element is changed into Mn4+. The LiSi/LiCl-KCl/ ( MnO2/G) cell has two discharge platforms for 2. 58 V and 1. 96 V, respectively, when discharge voltage cut-off to 1. 0 V, the corresponding discharge specific capacity reach 1150. 2 mAh/g.