Deeply Understanding Functional Separators in Different pH Aqueous Zinc‐Based Batteries: Design Principles, Modification Strategies, Opportunities, and Challenges

Abstract Aqueous zinc‐based batteries (AZBBs) have become promising candidates for large‐scale grid energy storage due to their advantages of high safety, low cost, and environmental friendliness. However, whether it is alkaline batteries or acidic/neutral batteries, issues such as the growth of zinc dendrites, side reactions, shuttle effects, and electrode contradictions have hindered the further development of AZBBs. The functionalized separator modification strategy has been proven to be an effective approach for enhancing the stability of anodes or cathodes. To this day, the inherent mechanism of functional separators in different pH electrolyte environments remains unclear. Therefore, this review first introduces the requirements for functional separators under different pH electrolyte environments and corresponding design principles. Then, the research progress of AZBBs functional separators under different pH aqueous solution systems is summarized. Subsequently, in response to the four main problems faced by AZBBs mentioned above, the corresponding modification strategies and mechanisms are introduced in detail. Finally, the development of functional separators in AZBBs is prospected, aiming to promote the commercialization path of the booming AZBBs.