High Performance Hybrid Supercapacitor Based on Graphene-Supported Ni(OH)₂-Nanowires and Ordered Mesoporous Carbon CMK-5

In this work, graphene-supported Ni(OH) 2 -nanowires were prepared through a facile hydrothermal method, and their charge storage behavior was studied in comparison with ordered mesoporous carbon CMK-5. The as-prepared Ni(OH) 2 -nanowires displays ultrafast charge-discharge rate, owing to their unique nanostructure. The comparison investigation demonstrates that the capacitance of graphene-supported Ni(OH) 2 -nanowires mainly arises from battery behavior, rather than pseudocapacitive behavior. Finally, the graphene-supported Ni(OH) 2 -nanowires and CMK-5 were used as the positive and negative electrode, respectively, to form a high performance hybrid supercapacitor which can deliver a maximum specific power density of 40840 W/kg with a high energy density of about 17.3 Wh/kg. Thereby, this hybrid supercapacitor should be a promising system for fast energy storage.