Cellulose Materials Integrate Ion Transport, Interfacial Chemistry, and Structural Stability in Zinc Battery Systems

Rechargeable zinc batteries offer a promising route toward safe, low‐cost, and sustainable energy storage, but their practical application is hindered by nonuniform ion transport, parasitic interfacial reactions, and progressive structural degradation. Cellulose is attractive because its oxygen‐containing functional groups, hierarchical fibrous structure, and processable networks can be tailored for zinc anodes, electrolytes, separators, cathodes, and flexible devices. This Review discusses recent advances in cellulose‐based materials for mild aqueous zinc‐ion batteries and alkaline zinc‐air batteries, focusing on how chemical modification, nanoscale organization, pore structure, and wet‐state mechanics affect ion conduction, electrode/electrolyte contact, and structural retention. Particular attention is given to the evidence supporting proposed mechanisms and to the distinct reaction environments of the two systems, including Zn 2+ transport and plating/stripping in mild electrolytes, and OH − transport, zincate redistribution, ZnO evolution, and air‐electrode processes in alkaline cells. The Review also examines performance trade‐offs, component contributions in multicomponent systems, and the limits of comparisons across different testing conditions. By linking cellulose chemistry and architecture with chemistry‐specific battery requirements, it provides practical guidance for material selection, mechanism verification, and device‐oriented design, while identifying chemical durability, dimensional stability, feedstock consistency, standardized evaluation, and scalable manufacturing as priorities for future development.