Triple‐Functional Amorphous In₂O₃ Anode Protection Layer Design for High‐Performance Aqueous Zinc Ion Batteries

Abstract Protective coatings for Zn anode are developed to suppress Zn dendrite growth, inhibit hydrogen evolution reaction (HER), and provide good anti‐corrosion properties. However, preparing protective coatings with all three of these characteristics remains a challenge. In this study, a triple‐functional amorphous In 2 O 3 protective layer for Zn anodes is designed. The high redox potential of In/In 3+ ensures the stability of the coating in aqueous electrolytes and effectively suppresses HER. Theoretical calculations indicate that the amorphous In₂O₃ protective layer has high Zn 2 ⁺ affinity, which lowers the nucleation barrier for Zn 2 ⁺ and suppresses dendrite growth. Furthermore, the anisotropy of this amorphous material provides homogeneous Zn 2+ adsorption sites and enhances corrosion resistance. Consequently, amorphous In 2 O 3 @Zn symmetric batteries have excellent stability and a cycle life far exceeding that of bare Zn, showing the ability to undergo continuous stripping/plating at 1 mA cm −2 for >5400 h. At a current density of 10 A g −1 , an amorphous In 2 O 3 @Zn//Ca‐V 2 O 5 full cell retains a specific capacity of 307.3 mA h g −1 after 5000 cycles (cycle retention: 76%). The successful preparation of In 2 O 3 @Zn provides a new approach for obtaining highly stable and long‐life Zn anodes.