Regulating Interfacial Solvation and Local pH via a Zincophilic 5-Phenyl-1H-tetrazole Protective Layer for Highly Reversible Zinc Anodes

A 5-Ph-Tet protective layer is engineered on Zn for dendrite-free aqueous zinc-ion batteries. • Strong Zn-tetrazole coordination lowers the desolvation barrier and guides preferential Zn (002) deposition. • The layer suppresses byproduct formation by modulating the interfacial chemical environment. • It enables 3400 h of cycling in a symmetric cell and 5000 cycles in a Zn@5-Ph-Tet||NVO full cell. Constructing an artificial interfacial protective coating on the zinc surface represents a facile yet effective strategy to suppress dendrite growth and parasitic reactions in aqueous zinc-ion batteries. In this work, a protective coating containing 5-phenyl-1H-tetrazole (5-Ph-Tet) was applied onto the zinc anode surface. Owing to its electrochemical properties and a pKa of approximately 4.3, 5-Ph-Tet can buffer local pH variations at the zinc anode interface during the inevitable hydrogen evolution reaction (HER). Furthermore, the abundant zincophilic nitrogen atoms on 5-Ph-Tet coordinate with Zn 2+ , thereby facilitating uniform Zn deposition. Electrochemical evaluations validated the effectiveness of the 5-Ph-Tet protective layer: the symmetric cell exhibited a cycling life of 3400 h under the testing conditions of 1 mA cm −2 and 1 mAh cm −2 (versus only 105 h for Bare Zn), while the Zn||NVO full cell demonstrated excellent cycling stability at 1 A g −1 , remaining free from short-circuiting even after 5000 cycles. This work offers a new strategy for future investigations into anode protection in aqueous zinc-ion batteries.