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 volume 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 cathode for the zinc-nickel flow battery. The nanoscale nickel phosphide alloy with high electronic conductivity (4.4 × 10-3 S m−1) can validly restrain the formation of overcharged production (γ-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.