Design and fabrication of cactus-like ZnCo2O4@Ni(OH)2 core/shell nanosheet arrays electrode for asymmetric supercapacitors

Supercapacitor has received much attention owing to their high efficiency and environmental friendliness. In this study, we synthesize cactus-like ZnCo2O4@Ni(OH)(2) core/shell nanosheets as electrode materials by a two-step hydrothermal method. The heterogeneous material consists of high capacitive core and high conductive shell. The structure can relieve the agglomeration of Ni(OH)(2) nanowires and improve the conductivity of core material. The electrode material delivers excellent electrochemical performance due to the fact that the synergistic effect of ZnCo2O4 and Ni(OH)(2) is fully utilized. ZnCo2O4@Ni(OH)(2) sample delivers a specific capacity of 2276 F/g at 1 A/g and 1388 F/g at 10 A/g. A flexible asymmetric supercapacitor is assembled using the synthesized product as cathode. It possesses an energy density of 75.1 Wh/kg at 1273.6 W/kg.