Ultralight flexible 3D nickel micromesh decorated with NiCoP for high stability alkaline zinc batteries

Abstract

Rechargeable alkaline zinc batteries are emerging as promising candidates for next-generation energy storage systems, owing to their affordability, eco-friendliness and high energy density. However, their widespread application is hindered by stability challenges, particularly in alkaline environments, due to cathode corrosion and deformation, as well as dendrite formation and unwanted side reactions at the Zn anode. To address these issues, we successfully developed a 3D nickel micromesh-supported NiCoP (3D NM@NiCoP) electrode. This unique structure integrates an ultrathin (4 μm), flexible and conductive nickel micromesh (NM) with a high-capacity bimetallic phosphide, NiCoP, fabricated through a combination of photolithography, chemical etching, and electro-deposition processes. The resulting electrode achieves an impressive capacitance of 26.1 μA h cm⁻² at a current density of 4 mA cm⁻² in a 2 M KOH electrolyte. When assembled with a superhydrophilic Zn@Al₂O₃@TiO₂ anode, the device (3D NM@NiCoP//Zn@Al₂O₃@TiO₂) exhibits outstanding stability, retaining 91% of its initial capacity after 11 000 cycles at 3 mA cm⁻² in a 2 M KOH electrolyte. This novel configuration, with potential for scalable fabrication, provides valuable insights into the development of high-capacity and durable electrodes for alkaline zinc batteries.