Taming Zinc Electrodeposition from the Root to Break Zinc Utilization/Capacity Barriers in Practical Zinc Batteries

Abstract

Developing practical zinc (Zn) batteries necessitates taming Zn electrodeposition at source to suppress associated unfavorable reactions while enhancing Zn utilization efficiency at commercially relevant areal capacities (≥10 mAh cm-2). This work overcomes key limitations in Zn utilization (99% in half-cells) and areal capacity through fundamental insights into Zn electrochemistry on tailored current collects. Complementary in-situ characterization and simulations reveal that the tailored brass (Cu0.7Zn0.3) establishes a zincophilic interface, homogeneous electric field distribution, and proton-rejecting properties. This synergy promotes uniform Zn diffusion and progressive nucleation, enabling dendrite-free deposition and effective suppression of water-induced side reactions. The Zn|Brass half-cell achieves an ultrahigh areal capacity of 50 mAh cm-2. In a static Zn-Br2 battery, it delivers 20000 stable cycles at 1 mAh cm-2, while exhibits a scalable areal capacity up to 50 mAh cm-2. A 200 mAh Zn-Br2 pouch cell sustains 1000 cycles, with high reversibility extending to 1000 mAh. The pouch cell offers a practical energy density of 61 Wh kg-1, safe operation, and compatibility with renewable energy integration. This work establishes design guidelines of current collectors for Zn anodes, paving the way for the advancement of practical Zn battery technologies.