▎ 摘　　要

A simple hydrothermal approach was used to successfully fabricate NiO/G nanocomposites. Since the addition of nickel oxide nanoparticles (NiO) to graphene instead of conducting polymeric materials produces better capacitances and improved capacity retention. Graphene-based inorganic composites have been attracting more and more attention. The as prepared NiO/G nanocomposite is characterized by XRD, TEM, Raman, XPS and nitrogen adsorption/desorption. It is demonstrated that NiO nanoparticles adorn graphene sheets to generate hierarchical nanostructures with rich porosity (33.8 nm) and substantial specific surface area (51 m(2) g(-1)). Electrochemical characterization demonstrate that the mesoporous graphene/NiO can deliver a specific capacitance of 632 F g(-1) at a current density of 2 Ag-1 and have a capacitance retention of 99.7% at 2Ag(-1) after 6000 continuous charge-discharge cycles. In addition, the ASC constructed from NiO/G shows excellent energy density (30.56 Whkg(-1)), excellent power density (2800 Wkg(-1)) and impressive cycle performance (capacitance retention after 6000 cycles is approximately 92.7%). This strategy aids in the fabrication and utilization of hybrid nanocomposite in high-geared reversible supercapacitors.