Interface engineering of Co3O4 nanowire arrays with ultrafine NiO nanowires for high-performance rechargeable alkaline batteries.

Interface engineering multi-component core-shell nanostructures with highly efficient and reversible faradaic reactions for energy conversion storage devices is still a challenge. Here, Co3O4 nanowires@NiO ultrafine nanowires on Ni foam were well fabricated via coating the NiO ultrafine nanowires on porous Co3O4 nanowire arrays. The combination of structural and compositional advantages endows the Co3O4@NiO core-shell composites with excellent electrochemical performance, such as a favorable specific capacity of 0.71 mA h cm-2 at 3 mA cm-2, excellent rate capability and 85% retention rate up to 10,000 cycles. Rechargeable alkaline batteries with the Co3O4@NiO core-shell composites and AC as cathode and anode, respectively, had a high specific capacity of 0.51 mA h cm-2 and stable cycling ability (81% retention after 5000 cycles). The hierarchical core-shell heterostructure electrode exhibits excellent electrochemical performance, making it a very promising material for next-generation energy storage device applications.