Accelerating ZnO Formation with Hydroxoaluminate for a Stable Alkaline Zn Battery.

Ma, Yilin; Yi, Zhibin; Chen, Minghui; Sang, Yingji; Chen, Qing · Nano Lett · 2025

basic_science · Level V

Where this comes from

Abstract

Alkaline zinc (Zn) batteries offer the potential for safe and cost-effective energy storage; however, their cycle life is limited by issues, such as hydrogen evolution, ZnO passivation, and shape changes. While increased alkalinity can help address hydrogen evolution and passivation, Ca(OH)<sub>2</sub> has proven to be the most effective additive for mitigating shape changes. Nevertheless, its low solubility restricts both its consistency and its practical application. In this study, we demonstrate that hydroxoaluminate ions (Al(OH)<sub>4</sub><sup>-</sup>) provide a promising, soluble alternative. Kinetic analysis indicates that hydroxoaluminate accelerates interfacial ZnO formation, thereby suppressing shape changes, as confirmed by microstructural characterization. This approach extends the cycle life of a Zn-powder anode to over 370 cycles at a 20% depth of discharge in a Zn||NiOOH battery.