▎ 摘　　要

A three-dimensional (3D) reduced graphene oxide hydrogel (rGOH) was prepared by hydrothermal synthesis based on the electrostatic force and chemical reaction between graphene oxide (GO) and Ni ions in a nickel acetate solution. The Ni- rGOH fabricated in this study exhibited a highly increased surface area compared to NiO nanoparticles owing to the formation of 3D networks. After the reduction of functional groups in Ni- GOH, Ni- rGOH showed highly enhanced capacitance (351 F g(-1)) at a charge/ discharge current density of 0.625 A g(-1) and 90% capacitance retention after 1000 cycles. The energy density of Ni- rGOH was 175.5 W h kg(-1) at a power density of 1.125 kW kg(-1), while maintaining a highenergy density of 118 W h kg(-1) at a power density of 4.5 kW kg(-1)