Facile Synthesis of Co₃O₄/CoF₂·4H₂O/graphene Composites for Supercapacitor Electrodes

摘要

Co3O4/CoF2·4H2O/graphene composites and Co3O4/graphene composites are synthesized by a facilemicrowave-assisted hydrothermal synthesis, followed by calcining at 350 ℃. The synthesizedcomposites are characterized by X-ray diffraction, and scanning electron microscopy. Electrochemicalproperty of the prepared composites is measured by cyclic voltammetry and galvanostatic chargedischarge. Results show that Co3O4/CoF2·4H2O/graphene composites exhibit better specificcapacitance and retention ratio of initial specific capacitance when compared with Co3O4/graphenecomposites. Particularly, Co3O4/CoF2·4H2O/graphene composites prepared using CoSO4·7H2O asmaterial exhibit the highest specific capacitance at various current densities, retention ratio of thespecific capacitance at the current density ranging from 1 to 4 A g-1 and retention ratio of initialspecific capacitance after 1000 cycles, indicating excellent rate capability and cycling stability. Thesecharacteristics demonstrate that Co3O4/CoF2·4H2O/graphene composites prepared using CoSO4·7H2Oas material possess a great potential application in supercapacitors.