Polymers for Aqueous Zinc‐Ion Batteries: From Fundamental to Applications Across Core Components

Abstract Aqueous zinc‐ion batteries (AZIBs) comprising zinc anodes hold intrinsic safety and high energy density ideally for distributed and large‐scale energy storage, thus have generated intriguing properties and increasing research interests. Unlike organic batteries, AZIBs require different, sometimes even opposite design principles and preparation strategies in solvent, electrolyte, and separator. This is especially true for the polymer materials that are widely used as critical components in stabilizing metal anodes and functioning as high‐performance safe cathode materials. This review discusses the explicit compositional and structural requisite of polymeric components in AZIBs, with an emphasis on the exclusive molecular structure–property relationship that governs the stability, reversibility, and capacity of these devices. The usage of polymers is classified into five categories aligning with the primary architecture of AZIBs: separators, additives, hydrogel electrolytes, coatings, and electrode materials. The most recent advances in the structure/property interplay of polymers by novel synthesis and preparation techniques targeting stable AZIBs are summarized and discussed. The challenges and perspectives of multifunctional polymers in developing high‐performance AZIBs are also proposed.