Lithium Carboxymethyl Cellulose: From a Green Binder to a Sustainable Multifunctional Platform for Advanced Lithium‐Ion Batteries

ABSTRACT The development of high‐performance and sustainable lithium‐ion batteries urgently demands eco‐friendly materials that transcend conventional functions. Lithium Carboxymethyl Cellulose (CMC‐Li), a green, low‐cost, and water‐processable biopolymer derived from renewable cellulose, is emerging as a key enabler in this field. This review comprehensively summarizes recent advancements of CMC‐Li, highlighting its evolution from a simple binder to a versatile, multi‐role platform that significantly enhances battery sustainability. We elaborate on its multifunctional roles as an ion‐conducting binder for both liquid and solid‐state systems, an artificial solid‐electrolyte interphase (SEI) component for stabilizing lithium metal anodes, and a functional additive in solid polymer electrolytes. The underlying green advantages and mechanisms—including a unique Li ⁺ hopping transport, the formation of a stable LiF‐rich SEI, and dynamic binding interactions—are critically discussed. Furthermore, we systematically outline performance optimization strategies via physical blending, chemical modification, and process control to overcome intrinsic brittleness while maintaining its environmental benignity. Finally, current challenges and future research directions are prospected, emphasizing the potential of CMC‐Li as a multifunctional interface architect in next‐generation green energy storage systems, such as those with lithium metal anodes and high‐voltage cathodes. This review aims to provide insightful guidance for the rational design of CMC‐Li‐based materials for future sustainable batteries.