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.

由于其比能量密度高、成本低、无毒、生态友好和广泛可用，ZnO 被认为是一种很有前途的超级电容器设备赝电容材料。然而，其较差的电子和离子电导率限制了其作为超级电容器装置的功率密度和循环稳定性，从而限制了其在储能系统中的应用。在此，我们报告了一种新型混合纳米复合电极材料，该材料通过用石墨烯片对 ZnO 纳米颗粒进行三维导电包裹而开发，以显着提高超级电容器的效率。由石墨烯片包裹 ZnO 纳米球通过将单个 ZnO 桥接在一起创建了高导电通路，从而提高了超级电容器的倍率和循环性能。使用这种 ZnO-RGO 混合物制造的超级电容器装置在 1 A/g 的电流密度下表现出 1012 F/g 的高比电容。此外，ZnO-RGO 混合物能够实现 3534.6 W/kg 的出色功率密度、50.6 Wh/kg 的能量密度和 96.4% 的库仑效率。这些发现展示了 ZnO-RGO 混合纳米复合材料作为高性能超级电容器中电极的潜力。