Stabilization Perspective on Metal Anodes for Aqueous Batteries

Abstract Aqueous electrolyte‐based batteries have attracted increasing attention because of nonflammability, low cost, high power density, and environmental friendliness. However, the low energy density of aqueous lithium‐ion batteries caused by the narrow stable electrochemical window of water and electrode materials with low capacity severely limits their further development. In this regard, the development of metal anodes with high specific capacity shows excellent prospects. For example, metal zinc and aluminum anodes have high theoretical specific capacity, rich resources, and environmental friendliness, and can be used as promising anodes for high‐energy‐density aqueous rechargeable metal batteries. Unfortunately, metal anodes usually face balance issues with regard to stability and activity associated with dendrite growth and undesired side reactions in water‐based electrolytes, which is still a great challenge for aqueous metal batteries. In this review, various aqueous metal batteries including aqueous rechargeable metal batteries and aqueous metal–air batteries are summarized and highlighted. Recent advances in the design of high‐safety aqueous electrolytes and the strategies for metal anode protection are comprehensively reviewed. In addition, emerging challenges and some perspectives on the development of high‐energy‐density aqueous metal batteries are included.