Hierarchical cobalt oxide@Nickel-vanadium layer double hydroxide core/shell nanowire arrays with enhanced areal specific capacity for nickel-zinc batteries

The aqueous Nickel-Zinc batteries have advantages of high safety and environmental benignity. However, their low energy density and poor cycling stability hinder their widespread applications. To address these issues, we demonstrate here a well-aligned hierarchical nanowires array as an advanced cathode for Nickel-Zinc batteries, which is composed of Nickel-vanadium layered double hydroxide decorated on cobalt oxide with a core/sheath configuration featuring merits of high electrical conductivity, large specific surface area, and short diffusion pathway for ions and electrons. Benefiting from the hierarchy structure design and component synergistic effect, the nanowires array electrode with high mass-loading of 11.1 mg cm(-2) exhibits high areal capacity of 1.98 mAh cm(-2) at 5 mA cm(-2), 61.8% capacity retention at 50 mA cm(-2) and excellent cycling stability with 100% retention after 1000 cycles. Moreover, full cell of the as-fabricated nanowiress arrays//Zinc configuration delivers high operating voltage of 1.71 V, energy density up to 2.2 mWh cm(-2), power density up to 82.0 mW cm(-2) and remarkable cycling stability of 89% capacity retention after 1500 cycles, showing great potential for practical applications. This work may also bring new design opportunities for the well-defined nanoarrays electrode in other energy storage devices.