Promoting the cyclic and rate performance of nickel hydroxide with ZnO via electrodeposition for supercapacitor

Abstract

A novel Ni(OH)2/ZnO hydrangea-like structure is prepared via a facile electrodeposition strategy with the Ni(OH)2 flower-like particles growing on the ZnO layered carrier. This flower-like structure can take advantage of both ZnO and Ni(OH)2, leading to a fast ion/electron transport speed and structural stability, finally, attaining an outstanding specific capacitance (2264.55 F g−1 at 0.5 A g−1), excellent rate performance (601.09 F g−1 at 30 A g−1) and cycle stability (maintain 94.9% specific capacitance after 5000 cycles). The Ni-OH/ZnO//AC asymmetric supercapacitor device achieves a high energy density of 68.44 Wh kg−1 at a power density of 400 W kg−1, demonstrating great potential as an electrode material for energy storage devices. The mechanism of synergistic effect of Ni(OH)2 and ZnO mutually supporting composite structure to improve electrochemical properties is innovatively proposed.