Strategies for Strengthening Zn Metal Anodes in Aqueous Zinc-Ion Batteries─Current States and Perspectives

Aqueous zinc-ion batteries (AZIBs) stand out as a compelling alternative to their lithium-ion counterparts, boasting advantages such as cost-effectiveness, superior safety, and diminished environmental ramifications. Notwithstanding notable advancements in cathode materials for AZIBs, pivotal obstacles associated with the Zn metal anode remain largely underinvestigated, thus hindering their application in grid-scale storage, portable electronics, and so on. This review offers a comprehensive overview of the intrinsic challenges confronting Zn anodes in aqueous electrolytes, while also aggregating recent progress in mitigating these setbacks. Solutions are delineated across three paradigms: (1) strengthening Zn anodes through structural design, (2) enhancing Zn anodes by establishing protective layers, and (3) electrolyte optimization via additive incorporation and compositional adjustments. Each strategy undergoes rigorous scrutiny concerning its potential to curtail dendrite proliferation, impede parasitic HER, and bolster electrochemical resilience. Additionally, future research directions such as AI-driven optimization, high-entropy approaches, and bio-inspired strategies are discussed to advance high-performance AZIBs toward practical applications.