From electrode to electrolyte and separator: the versatile roles of conductive polymers in aqueous zinc-ion batteries

Conductive polymers (CPs) have emerged as a versatile material platform for addressing the critical challenges of aqueous zinc-ion batteries (AZIBs), yet a comprehensive understanding of their multifunctional roles across the full battery system remains lacking. This review provides a systematic, mechanism-driven overview of CP applications in AZIBs from a holistic "cathode-electrolyte/separator-anode" chain perspective. Firstly, we establish the structural characteristics and synthesis methods of CPs, followed by a summary of zinc storage mechanisms in cathode systems. The multifaceted roles of CPs in cathodes are then comprehensively analyzed, including their functions as surface coatings, interlayer intercalants, standalone active materials, and carbon-based composites, with detailed discussion on how they address the intrinsic limitations of inorganic cathodes and optimize organic electrode performance. Subsequently, CP-driven strategies in electrolyte and separator engineering are critically evaluated, covering interfacial modification, electrolyte additives, gel/solid polymer electrolytes, and functional separators. For zinc anode stabilization, two complementary mechanisms are established: interfacial chemical environment reconstruction coupled with solvation behavior regulation, and interfacial electric field homogenization integrated with selective ion transport. Finally, we summarize the core advantages of CPs in AZIBs and identify unresolved challenges, including controllable synthesis, quantitative mechanistic understanding, advanced characterization techniques, and industrial scalability, offering forward-looking perspectives to bridge the gap between laboratory research and practical commercialization of high-performance CP-integrated AZIBs.