Boron-Fluoride Dual-atom Synergistic Regulated Interface Coating Enables Stable Zn-metal Anodes

Abstract

Aqueous Zinc-based batteries provide promising opportunities for next-generation rechargeable batteries. Nevertheless, Zn anode encounters severe challenges, such as Zn dendrite formation, surface corrosion, and hydrogen evolution reaction (HER). Here, we report a strategy to spontaneously construct a boron-fluoride dual-atom regulated SEI (ZnBOF), which involves the formation of a B-compound coating through etching process and followed by an in-situ F substitution during the initial electrochemical cycling. The ZnBOF/Zn anode benefit preferential deposition of Zn2+ along the (002) plane without Zn dendrite, and the side reaction including by-product and HER are dramatically suppressed. A combination of characterization methods, such as X-ray absorption spectroscopy, show that the B-containing passivation layer facilitates the transport of Zn2+ and mitigates water-related side reactions, and the F atoms serve as zincophilic sites that enhance the transfer kinetics of Zn2+. As expected, the well-designed ZnBOF/Zn anode exhibits ultra-stable Zn plating/stripping for 5000 h at 2 mA cm-2. The assembled ZnBOF/Zn||MnO2 batteries show impressive cycling stability, remaining 96.2% of the initial capacity (234.3 mAh g-1) after 1700 cycles at 1.0 A g-1. Therefore, this work reveals a dual-atom synergistic regulated strategy to fabricate a robust SEI for Zn anode, which contributes to the development of aqueous zinc-based batteries.