Challenges, Strategies, and Perspectives of Anode Protection in Aqueous Zinc-Ion Batteries

Aqueous zinc-ion batteries (ZIBs) have emerged as one of the promising scalable electrochemical energy storage system alternatives to current alkali metal-based batteries due to their high safety, nontoxicity, abundant raw material sources, and facile device fabrication. However, their inherent water-containing electrolyte nature raises the problems of severe dendrite growth, competing hydrogen evolution, and passivation at the anode side, considerably restricting the practical applications of aqueous ZIBs. In this review, considering these main existing challenges, we first review the key protection strategies of zinc anodes from three aspects, including constructing Zn anodes, building an artificial interface layer, and tailoring electrolyte composition, for regulating the Zn-ion deposition kinetics and mitigating the water reactivity. In the end, we explore several key considerations that must be taken into account to promote the development and future practical applications of aqueous zinc-ion batteries.