Synthesis of hierarchical Cu2O octahedra@Ni(OH)2 nanosheets core-shell heterostructures for high-performance supercapacitor

Abstract

In this work, we report the controllable preparation of hierarchical Cu2O octahedra@Ni(OH)2 nanosheets core-shell heterostructures and their application in high-performance supercapacitors. Cu2O octahedra are initially directly grown on Ni foam via a facile solvothermal reaction, followed by the covering of Ni(OH)2 nanosheets through a controllable electrodeposition method. The prepared Cu2O@Ni(OH)2 core-shell heterostructures were found to exhibit a specific capacitance of up to 892 F g−1 at 1 A g−1 and a capacitance retention of 95% after 5000 cycles at 5 A g−1. Such good electrochemical performance is believed to arise from its unique octahedra@nanosheets core-shell heterostructures and synergistic effect of the Cu2O and Ni(OH)2 components. Moreover, the assembled Cu2O@Ni(OH)2//active carbon asymmetric supercapacitor device could deliver an energy density of 34.8 W h kg−1 at a power density of 798 W kg−1. Our findings not only suggest the great potential of the prepared Cu2O@Ni(OH)2 core-shell heterostructures for use in energy storage devices, but also showcase an alternative approach to construct the composite electrodes with high electrochemical performance.