Surface Segregation Reconstructing Alloy Substrate for Ultra-Stable Zinc-Based Batteries.

Abstract

Aqueous zinc-based batteries (AZBs) are promising candidates for large-scale energy storage owing to their high safety, low cost, and eco-friendliness, but uncontrolled dendrite growth, low zinc (Zn) utilization, and resulting reduced energy density hinder their practical applications. Inert current collectors alleviate partial issues from excessive Zn loading, yet commercial metal foils suffer from rolling defects and localized Zn deposition. This work proposes a segregation strategy that induces directional inward tin (Sn) atom migration in copper-tin (Cu-Sn) alloy substrates via diffusion rate disparity by a 1-min heating process, forming a reconstructed surface that facilitates uniform Zn deposition. This reconstruction establishes triple synergistic optimization, including reducing nucleation barriers by exposing Cu (111) facets, creating uniform voids and CuO particles for homogeneous Zn nucleation, and eliminating rolling defects to enable dense Zn deposition. Based on these synergistic effects, the asymmetric cell exhibits exceptional cycling stability over ≈10 000 cycles with 99.8% Coulombic efficiency. Zn-I₂ coin cells achieve ultra-stable 40 000 cycles, while pouch cells exhibit ultra-long 5000-h cycling stability with a 91% capacity retention rate, demonstrating superior stability for practical applications. Combining efficiency, cost-effectiveness, and scalability, this work provides a critical pathway for sustainable development and potential commercialization of AZBs.