Biomass‐Derived Quasi‐Solid‐State Electrolytes for Zinc‐Based Batteries: Empowering New Energy Storage

ABSTRACT Aqueous zinc‐based batteries (ZBs) are widely regarded as highly promising candidates for next‐generation energy storage, primarily owing to their intrinsic safety, cost‐effectiveness, and impressive energy density. Nevertheless, their practical commercialization is severely bottlenecked by chronic interfacial instabilities, including uncontrollable zinc dendrite proliferation and severe water‐induced parasitic reactions. To fundamentally address these common challenges, transitioning from liquid electrolytes to quasi‐solid‐state electrolytes (QSSEs) is a highly promising approach. Among the various QSSEs matrixes, natural biomass materials such as cellulose, alginate, chitosan, and lignin have emerged as excellent candidates for framework materials due to their abundant availability, natural sustainability, and unique physicochemical properties. This review comprehensively examines the recent advancements in biomass‐derived QSSEs for ZBs. We systematically elucidate the core energy storage mechanisms and the indispensable role of biomass functional moieties in regulating the Zn 2+ solvation sheath to suppress side reactions. Furthermore, we critically analyze performance‐oriented structural engineering strategies aimed at decoupling ionic conductivity from mechanical robustness, broadening thermal adaptability, and optimizing electrode–electrolyte interfacial compatibility. Finally, we highlight the current progress of these materials across diverse solvent systems and outline the persisting bottlenecks, providing a strategic roadmap for the future design of highly reversible, environmentally benign ZBs.