Enhanced performance of asymmetric supercapacitor based on NiZn-LDH@NiCoSe 2 electrode materials

Abstract While supercapacitors have been widely studied as the next generation of energy storage devices, to develop active electrode materials for enhancing device performance is still challenging. Herein, we fabricated asymmetric supercapacitors based on NiZn-Layered double hydroxide (LDH) @NiCoSe 2 hierarchical nanostructures as electrode materials. The NiZn-LDH@NiCoSe 2 composites are deposited on Ni foam by a two-step strategy, in which NiZn-LDH nanosheets were firstly grown on Ni foam by hydrothermal method, and then NiCoSe 2 particles were prepared by electrodeposition. Due to the synergistic effect between NiZn-LDH and NiCoSe 2 , excellent device performance was achieved. In a three-electrode system, the NiZn-LDH@NiCoSe 2 exhibits a specific capacitance of 2980 F g −1 at 1 A g −1 . Furthermore, the asymmetric supercapacitor of NiZn-LDH@NiCoSe 2 //activated carbon (AC) device was assembled, which exhibits the energy density of 49.2 Wh kg −1 at the power density of 160 W kg −1 , with the capacity retention rate is 91% after 8000 cycles. The results indicates that NiZn-LDH@NiCoSe 2 is a promising candidate as electrode materials for efficient energy storage devices.