▎ 摘　　要

The graphene/Fe3O4 (GN/Fe3O4) nanocomposites used as electrode of supercapacitors were prepared by chemical reduction-high temperature treatment. The Fe3O4 with uniform size regularly decorate on the surface of graphene. According to the charge and discharge test, the GN/Fe3O4-0.05 electrode has the good mass specific capacitance (265.6 F/g) at a current density of 0.5 A/g. When the power density is 20.27 kW/kg, the energy density reaches 11.26 Wh/kg. Finally, the button supercapacitors were assembled used the prepared nanocomposites as electrodes. The nanocomposites exhibit stable capacitance efficiency after 100 cycles of charging and discharging. The capacitance efficiency still exceeds 80% after 500 cycles of charging and discharge, indicating that the nanocomposite has excellent cycle stability.