▎ 摘　　要

In this paper, a combination of deft dipping and simple rapid electrochemical reduction were used to coat electrochemically reduced graphene oxide (ERGO) on Ni foam. After acid etching, a 3D ERGO with sufficient mechanical strength, low density and high electrical conductivity was obtained. As proof, a high mass loading of Co3O4 sheets has been grown on the 3D ERGO. The 3D ERGO/Co3O4 composite electrode exhibits a specific capacitance of 600 F g(-1) and a power density of 2.5 kW kg(-1).