In Situ Buildup of Zinc Anode Protection Films with Natural Protein Additives for High-Performance Zinc Battery Cycling

The uncontrolled growth of dendrites and serious side reactions, such as hydrogen evolution and corrosion, significantly hinder the industrial application and development of aqueous zinc-ion batteries (ZIBs). This article presents ovalbumin (OVA) as a multifunctional electrolyte additive for aqueous ZIBs. Experimental characterizations and theoretical calculations reveal that the OVA additive can replace the solvated sheath of recombinant hydrated Zn²⁺ through the coordination water, preferentially adsorb on the surface of the Zn anode, and construct a high-quality self-healing protective film. Notably, the OVA-based protective film with strong Zn²⁺ affinity will promote uniform Zn deposition and inhibit side reactions. As a result, Zn||Zn symmetrical batteries in ZnSO₄ electrolytes containing OVA achieve a cycle life exceeding 2200 h. Zn||Cu batteries and Zn||MnO₂ (2 A g^-1) full batteries show excellent cycling stability for 2500 cycles, demonstrating promising application prospects. This study provides insights into utilizing natural protein molecules to modulate the kinetics of Zn²⁺ diffusion and enhance the stability of the anode interface.