Fabrication of Al-doped ZnO microspheres as negative materials for superior cycling stability in nickel-zinc secondary batteries

Abstract

Alkaline nickel-zinc (Ni-Zn) batteries are gaining traction as a promising energy storage solution, thanks to their remarkable specific power density, built-in safety features, and affordability. Nonetheless, the zinc-based anodes face significant issues such as structural changes, dendrite formation, and electrochemical degradation, which greatly hinder the cycling stability and lifespan of these batteries. To overcome these challenges, this study introduces a metal doping approach, integrating a controlled amount of aluminum into zinc oxide (ZnO) via solvothermal synthesis followed by calcination. This process yields a spherical composite of aluminum-doped ZnO (AZO x ) made up of porous nanosheets. The enhanced cyclic stability of the AZO 5 composite is attributed to the beneficial interplay between the optimized aluminum doping and its three-dimensional porous architecture. The addition of aluminum improves electronic conductivity, while the porous structure increases the number of reaction sites, facilitating better Zn 2+ deposition kinetics and minimizing electrode degradation. This composite demonstrates excellent cycling stability in nickel-zinc rechargeable batteries. This research paves the way for developing high-performance anode materials for Ni-Zn batteries, potentially expediting their commercialization.