Polymer engineering for electrodes of aqueous zinc ion batteries

With the increasing demand for scalable and cost-effective electrochemical energy storage, aqueous zinc ion batteries (AZIBs) have a broad application prospect as an inexpensive, efficient, and naturally secure energy storage device. However, the limitations suffered by AZIBs, including volume expansion and active materials dissolution of the cathode, electrochemical corrosion, irreversible side reactions, zinc dendrites of the anode, have seriously decelerated the civilianization process of AZIBs. Currently, polymers have tremendous superiority for application in AZIBs attributed to their exceptional chemical stability, tunable structure, high energy density and outstanding mechanical properties. Considering the expanding applications of AZIBs and the superiority of polymers, this comprehensive paper meticulously reviews the benefits of utilizing polymeric applied to cathodes and anodes, respectively. To begin with, with adjustable structure as an entry point, the correlation between polymer structure and the function of energy storage as well as optimization is deeply investigated in respect to the mechanism. Then, depending on the diversity of properties and structures, the development of polymers in AZIBs is summarized, including conductive polymers, redox polymers as well as carbon composite polymers for cathode and polyvinylidene fluoride-, carbonyl-, amino-, nitrile-based polymers for anode, and a comprehensive evaluation of the shortcomings of these strategies is provided. Finally, an outlook highlights some of the challenges posed by the application of polymers and offers insights into the potential future direction of polymers in AZIBs. It is designed to provide a thorough reference for researchers and developers working on polymer for AZIBs.