Simple preparation of graphene-decorated NiCo_2O_4 hollow nanospheres with enhanced performance for supercapacitor

摘要

Supercapacitor is a new kind of energy storage devices with characteristics of high power density, fast charge–discharge rate and long cycle life. In this paper, graphene-decorated NiCo~(2)O~(4)hollow nanospheres (GE/NiCo~(2)O~(4)) were synthesized by a consecutive hydrothermal and sintering method for supercapacitor application. The structures and morphologies of the samples were characterized by XRD, SEM and TEM. The electrochemical properties of the electrodes were measured by CV, CDC and EIS. The testing results showed that the specific capacitance, rate capability and stability the GE/NiCo~(2)O~(4)electrode are obviously improved in comparison to those of single NiCo~(2)O~(4)electrode, which demonstrated that introducing graphene onto the surface of NiCo~(2)O~(4)hollow nanospheres can produce high-performance composite electrode material for supercapacitor application.