A novel three-dimensional hierarchical NiCo2O4/Ni2P electrode for high energy asymmetric supercapacitor

Herein, a novel three-dimensional hierarchical NiCo2O4/Ni2P structure is successfully fabricated through a facile] hydrothermal and subsequent electrodeposition process. One-dimensional Ni2P nanoneedles decorate on two-dimensional NiCo2O4 nanosheets can effectively enhance the electrical conductivity and surface area of NiCo2O4 to promote fast Faradaic reaction. The optimized NiCo2O4/Ni2P-30 electrode exhibits a high specific capacity of 2900 F g(-1) at 0.008 A cm(-2). Moreover, an asymmetric supercapacitor (ASC) is fabricated by using the NiCo2O4/Ni2P-30 as positive electrode and activated carbon as the negative electrode, the device achieves an excellent electrochemical property with the energy density of 40.7Wh kg(-1) at 800Wkg(-1). Besides, the as-assembled device also exhibits an excellent cycling performance of similar to 92.0% of initial capacitance after 5000 cycles indicating its outstanding conductivity and structural stability. All of the results demonstrate that the hierarchical NiCo2O4/Ni2P composites are electrodes in energy storage application.