▎ 摘　　要

MnC2O4/graphene composites are prepared by a facile hydrothermal reaction with KMnO4 using ascorbic acid as a reducing agent. Olive-like MnC2O4 particles are distributed uniformly on the surface of graphene sheets. The composites are evaluated as supercapacitor electrodes, which show that the specific capacitance of MnC2O4/graphene composites is 122 F g(-1), more than twice as high as that of free MnC2O4 at a current density of 0.5 A g(-1). In addition, this composite material exhibits an excellent cycle stability with the capacitance retention of 94.3 % after 1,000 cycles.