Solvothermal Synthesis and Performances of NiO/Reduced Graphene Oxide for Supercapacitor Electrode Material with Long Cycle Stability

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.