Surface topography optimization engineering : stabilizing zinc metal anode/aqueous electrolyte interfacial chemistry

Abstract

Unstable metallic Zn anode (MZA)/electrolyte interfacial chemistry has long blocked the practical implementation of aqueous Zn metal batteries (ZMBs). Herein, this study presents an innovative surface topology optimization engineering via an efficient laser-texturing technique to achieve the front-end design of MZA for enhanced interface stability. Specifically, the laser-textured MZA features an in situ formed ZnO coating with a high-density, ordered micro-pits array architecture (LT-Zn@ZnO). Systematic experimental analyses and theoretical calculations reveal that the LT-Zn@ZnO ensures a more uniform electric field distribution and stronger corrosion resistance than pristine Zn foil. These enhancements effectively suppress dendrite proliferation and hydrogen evolution on the LT-Zn@ZnO surface, achieving more stable LT-Zn@ZnO/electrolyte interfacial chemistry. Therefore, the LT-Zn@ZnO acquires exceptional electrochemical reversibility, sustaining over 1840 h at 10 mA cm−2/1 mAh cm−2. This results in the assembled large-sized (24 cm2) LT-Zn@ZnO Ti@MnO₂ pouch cell achieving a higher initial capacity of 158.6 mAh and significantly improved rechargeability, retaining 105 mAh after 400 cycles, compared to that employing untreated Zn foil, which has an initial capacity of 144.7 mAh and failed in fewer than 200 cycles. The presented surface topography optimization strategy offers an innovative solution for front-end design enhancement of MZA, leading to improved electrochemical reversibility toward ZMBs with satisfactory rechargeability.