Enhanced stability of nickel cathode for nickel-based batteries by electroless nickel phosphide plating

Cost-effective and high-performance nickel-based batteries are well-suited for energy storage. However, the application of most nickel-based batteries such as alkaline zinc-nickel flow battery is hindered by vol-ume expansion and oxygen evolution side reaction of nickel cathode. Herein, we propose an "Inside-out" strategy to address these issues by in-situ electroless plating of uniform nickel phosphide on nickel cath-ode for the zinc-nickel flow battery. The nanoscale nickel phosphide alloy with high electronic conduc-tivity (4.4 x 10-3 S m-1) can validly restrain the formation of overcharged production (y-NiOOH) and volume expansion of nickel cathode. The alkaline zinc-nickel flow battery using the modified cathode demonstrates a coulombic efficiency of 98.7 % and a voltage efficiency of 86.2 % at a current density of 40 mA cm-2, along with significant suppression of oxygen evolution side reaction (<50 ppm). This work may inspire the development of high-performance nickel cathodes, which are highly desirable to achieve high-performance nickel-based batteries. (c) 2023 Elsevier Ltd. All rights reserved.