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

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. • A novel Ni(OH) 2 /ZnO hydrangea-like structure is prepared via electrodeposition. • Outstanding cyclic and rate performance is achieved due to the supporting of ZnO. • The composite fulfills an outstanding capacitance of 2264.55 F g−1 at 0.5 A g−1. • The synergistic effect of mutually supporting structure is discussed in detail. [ABSTRACT FROM AUTHOR]