Abstract: The NiO nanoflowers and NiO/reduced graphene oxide(rGO) composite were synthesized by a facile solvothermal process following thermal treatments. In the NiO/rGO composite, rGO was used as the substrate to fix NiO while the NiO acted as the spacer to prevent the aggregation of rGO. The composition, morphology and microstructure of the as-obtained samples were systematically characterized by thermogravimetric(TG) analysis, field emission scanning electron microscopy(FE-SEM) and X-ray diffraction(XRD). When NiO/rGO composite(the mass ratio of NiO to rGO is up to 82.7∶17.3) was used as a single electrode, it exhibited excellent electrochemical performance. At 1 A/g, the initial specific capacitance was 514.9 F/g. When the material was fully activated, the specific capacitance was high(up to 600 F/g). Meanwhile, at the current density of 10 A/g, there is 83.5% retention in the capacitance relative to 1 A/g. In addition, the electrode material exhibits excellent recyclic stability, the capacitance decay rate is only 7.4% after 6000 cycles. Thus, the as-prepared composite has the practical value in supercapacitors.

Key words: NiO, reduced graphene oxide, solvothermal method, composite electrode material