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.
Keywords: Zn anode protection; in situ protective films; natural protein additives; ovalbumin; zinc-ion batteries.