▎ 摘　　要

We synthesized Ni(OH)(2) nanowires/three-dimensional graphene composites using a hydrothermal method, and compared their properties with those of three-dimensional graphene, Ni(OH)(2) nanowires, reduced graphene oxide, and Ni(OH)(2) nanowires/reduced graphene oxide. The samples were characterized using Xray diffraction, scanning electron microscopy, thermogravimetric analysis, and N-2 physisorption measurements. The electrochemical performances were investigated using cyclic voltammetry and galvanostatic charge-discharge methods. The results showed that Ni(OH)(2) nanowires of width 20-30 nm were closely combined with graphene and crosslinked to one another to form a three-dimensional structure with a high specific surface area (136 m(2).g(-1)) and mesoporosity (pore diameter 20-50 nm). The mass fraction of Ni(OH)(2) nanowires in the Ni(OH)(2) nanowires/three-dimensional graphene composite was 88%. The maximum specific capacitance of the Ni(OH)(2) nanowires/three-dimensional graphene composite was 1664 F.g(-1) in 6 mol.L-1 KOH electrolyte at 1 A.g(-1). The specific capacitance decreased by only 7% after 3000 cycles at 1 A.g(-1). A comparative study of the specific capacitances and cycling performances of Ni(OH)(2) nanowires, Ni(OH)(2) nanowires/reduced graphene oxide, three-dimensional graphene, reduced graphene oxide, and Ni(OH)(2) nanowires/three-dimensional graphene indicated that three-dimensional graphene with three-dimensional porosity and a larger specific surface area than conventional reduced graphene oxide enabled improved use of the active material and significantly enhanced the electrochemical performance of Ni(OH)(2) nanowires.