Design and fabrication of different metal oxide nanosphere with hierarchically porous structure is important for developing the performance of energy storage devices. In this present work, we have reported the fabrication of ZnO nanosphere decorated reduced graphene oxide (rGO) composite and its electrochemical performance for supercapacitive applications. The porous ZnO nanosphere embedded on rGO (ZnO@rGO) has been synthesized by a simple ex-situ wet chemical process. The specific capacitance of the composite material is investigated by using two-electrode configuration and from the galvanostatic charge-discharge plot the specific capacitance is obtained 949 F g^-1 at 1 Ag^-1. Integrating the pseudo-capacitive effect of porous ZnO nanosphere, and the electrochemical double layer of the reduced graphene oxide, the maximum energy and power density of 74 Wh kg⁻¹ and 374 W kg⁻¹ are achieved respectively at 1 Ag^-1. The ZnO@rGO composite is also observed to exhibit high cyclic stability and it retains 91% capacitance value even after 10,000 cycles, demonstrating good long-term stability. Increased specific surface area and presence of additional active sites due to the porous structure of ZnO nanosphere are proposed to be the primary factor for the superior electrochemical performance of ZnO@rGO based supercapacitor devices.

具有分层多孔结构的不同金属氧化物纳米球的设计和制造对于提高储能装置的性能很重要。在本工作中，我们已经报道了ZnO纳米球修饰的还原型氧化石墨烯（rGO）复合材料的制备及其在超级电容应用中的电化学性能。通过简单的非原位湿化学方法合成了嵌入rGO的多孔ZnO纳米球（ZnO @ rGO）。该复合材料的比电容是通过使用两个电极结构和从所述特定电容，获得949 F G的恒流充放电曲线图调查^-1 1的Ag ^-1。整合了多孔ZnO纳米球的拟电容效应和还原型氧化石墨烯的电化学双层，在1 Ag ^-1处分别获得74 Wh kg ^-1和374 W kg ^-1的最大能量和功率密度。还观察到ZnO @ rGO复合材料表现出高的循环稳定性，即使经过10,000次循环后仍保持91％的电容值，这表明其长期稳定性良好。ZnO纳米球的多孔结构导致比表面积增加和存在额外的活性位点，被认为是基于ZnO @ rGO的超级电容器器件优异电化学性能的主要因素。