▎ 摘　　要

Co3O4/CoF2 center dot 4H(2)O/graphene composites and Co3O4/graphene composites are synthesized by a facile microwave-assisted hydrothermal synthesis, followed by calcining at 350 degrees C. The synthesized composites are characterized by X-ray diffraction, and scanning electron microscopy. Electrochemical property of the prepared composites is measured by cyclic voltammetry and galvanostatic charge-discharge. Results show that Co3O4/CoF2 center dot 4H(2)O/graphene composites exhibit better specific capacitance and retention ratio of initial specific capacitance when compared with Co3O4/graphene composites. Particularly, Co3O4/CoF2 center dot 4H(2)O/graphene composites prepared using CoSO4 center dot 7H(2)O as material exhibit the highest specific capacitance at various current densities, retention ratio of the specific capacitance at the current density ranging from 1 to 4 A g(-1) and retention ratio of initial specific capacitance after 1000 cycles, indicating excellent rate capability and cycling stability. These characteristics demonstrate that Co3O4/CoF2 center dot 4H(2)O/graphene composites prepared using CoSO4 center dot 7H(2)O as material possess a great potential application in supercapacitors.