Zinc Anode Modification Using Biomass-Based Materials for High-Performance Zinc-Ion Batteries

Aqueous zinc-ion batteries (AZIBs) are promising candidates for next-generation large-scale energy storage systems due to their high safety, low cost, and environmental compatibility. However, the practical use of zinc metal anodes is limited by critical challenges, including dendrite growth, corrosion, and the formation of insulating by-products such as Zn₄SO₄(OH)₆·xH₂O (ZHS), which cause capacity fading and shorten cycle life. Recently, biomass-derived materials have attracted significant attention as sustainable, eco-friendly interfacial modification layers for zinc anodes, owing to their abundance, structural tunability, and diverse functional groups. This review categorizes biomass-based interfacial materials into three groups: (1) organic biomass polymers, including chitosan, lignin, cellulose, and hyaluronate; (2) biomass-derived carbons, valued for their high conductivity and mechanical strength; and (3) inorganic biomass materials, such as diatomite and transition-metal complexes. The mechanisms by which these materials suppress dendrite formation, inhibit corrosion, and enhance electrochemical performance are systematically analyzed, with representative advances highlighted. Current limitations, such as low ion conductivity, interfacial degradation during prolonged cycling, high manufacturing costs, limited scalability, and dependance on electrolyte composition, are also critically evaluated. Finally, future research directions are discussed, including the design of composite materials, surface functionalization strategies, operando characterization techniques, co-optimization of electrolytes and protective coatings, and scalable manufacturing processes. Overall, this review provides a comprehensive overview of biomass-based strategies for zinc anode engineering and establishes a foundation for the sustainable development of high-performance AZIBs.