▎ 摘　　要

ZnO is considered a promising pseudocapacitive material for supercapacitor devices because of its high specific energy density, low cost, non-toxicity, eco-friendliness, and widespread availability. However, its poor electronic and ionic conductivity limits its power density and cycling stability as a supercapacitor device, restricting its use in energy storage systems. Herein we report a novel hybrid nanocomposite electrode material developed by three-dimensional conducting wrapping of ZnO nanoparticles with graphene sheet to significantly improve the supercapacitor efficiency. The wrapping of ZnO nanospheres by graphene sheets creates highly conductive pathways by bridging individual ZnO together, thereby improving the rate and cycling performance of supercapacitors. The fabricated supercapacitor device using this ZnO-RGO hybrid exhibited a high specific capacitance of 1012 F/g at a current density of 1 A/g. Furthermore, the ZnO-RGO hybrid is capable of achieving an outstanding power density of 3534.6 W/kg, an energy density of 50.6 Wh/kg and a Coulombic efficiency of 96.4%. These findings exhibit the potential of the ZnO-RGO hybrid nanocomposites as an electrode in high-performance supercapacitors.