▎ 摘　　要

Mn3O4 was prepared by hydrothermal method with 180 degrees C as reaction temperature and 10 h as reaction time. The obtained samples were bar-like samples with high purity were evaluated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electrochemical performance of Mn3O4 was improved by Sn-doping. The specific capacitance of the composites obtained by compounding the modified materials with graphene was greatly increased and their cyclic voltammetric curves were rectangular, which shows that the graphene modified Mn3O4 has a pleasurable development prospect. For the pure Mn3O4, Sn-Mn3O4 and Sn-Mn3O4 / graphene composite, the specific capacitance of 21 F.g(-1), 30 F.g(-1) and 215 F.g(-1) were manifested by electrochemical work station, respectively. The results show that stannum and graphene greatly enhances the electrochemical performance of Mn3O4.