Engineering Interphasial Chemistry for Zn Anodes in Aqueous Zinc Ion Batteries

Aqueous zinc ion batteries (AZIBs) have emerged as promising candidates for large-scale energy storage systems during post lithium-ion era, drawing attention for their environmental-friendliness, cost-effectiveness, high safety, and minimal manufacturing constraints. However, the long-standing roadblock to their commercialization lies in the dendrite growth and parasitic reactions (hydrogen evolution reaction and water-induced corrosion) of the metallic zinc anode, which strongly depends on the complicated interphasial chemistries. This review, with a focus on optimizing the zinc anode/electrolyte interphase, begins by elucidating the intrinsic factor of zinc ions' migration, diffusion, nucleation, electro-crystallization, and growth of the zinc nucleus in AZIBs, along with the underlying scientific principles. Then the electrochemical theories pertinent to the plating behavior of the interphase is systematically clarified, thereby enriching the understanding of how anode structure and electrolyte design principles relate to the electrode interphase. Accordingly, the rational strategies emphasizing structural engineering of the zinc anode and electrolyte have been summarized and discussed in detail. The mechanisms, advances, drawbacks, and future outlook of these strategies are analyzed for the purpose of fabricating a chemically and electrochemically stable interphase. Finally, the challenging perspectives and major directions of zinc anode are proposed. This review is expected to shed light on developing high-performance Zn anodes for use in sustainable AZIBs.