A Facile In Situ Etching–coating of Artificial Solid‐Electrolyte Interphase on Zn Metal Anode for Aqueous Batteries

Abstract Zn metal anode is desired for aqueous batteries due to its high capacity and low redox potential. However, uneven Zn deposition and hydrogen evolution reaction (HER) have hindered the electrochemical reversibility and stability. Herein, an artificial solid electrolyte interphase (SEI) composed of metal center incorporated siloxane coupling with fluoride is in situ generated on Zn surface by a facile “etching–coating” process. This SZ‐SEI provides interaction sites with Zn 2+ , which helps with its desolvation at the interface and enlarges the transference number. Uniform Zn deposition underneath the layer is thus realized. Meanwhile, the SZ‐component hinders the adsorption of hydrogen atom and effectively suppresses HER. Thanks to the above effects, the cycle life of symmtric cells with SZ‐Zn electrodes extends to 2200 and 1400 h at the current densities of 10 and 20 mA cm −2 , respectively. The coulombic efficiency of Zn plating/stripping also reaches 99.8% for 3800 cycles. In addition, the SZ‐Zn anode enables better rate capability and cycling stability of full cells.