Cellulose-Based Materials for Sodium-ion Batteries: Advancements in Anodes, Electrolyte Systems, and Binders

The growing need for affordable and environmentally sustainable energy storage has positioned sodium-ion batteries (SIBs) as a viable alternative to lithium-ion technologies, especially in grid-scale and large-format applications. To improve the efficacy of SIBs, exploring abundant, renewable materials with enhanced electrochemical stability, ionic conductivity, and improved mechanical integrity is necessary. Among such materials, cellulose, the most abundant biopolymer on Earth, has attracted considerable interest due to its versatile structure, excellent mechanical strength, and tunable surface chemistry. This review highlights recent advances in the application of cellulose and its derivatives within key components of SIBs, including separators, electrolytes, binders, and electrodes. Cellulose-based gel polymer electrolytes have achieved ionic conductivities in the range of 10^-4-10^-3 S/cm and a Na⁺ transference number of up to 0.88, while cellulose-derived hard carbons deliver reversible capacities exceeding 300 mAh/g with coulombic efficiencies of 80-93 %. As green binders, carboxymethyl cellulose enables high initial coulombic efficiency (>85 %) and long-term cyclic stability, whereas cellulose membranes and separators exhibit liquid electrolyte uptake of ∼200-500 wt% and thermal stabilities of 150-300 °C. Despite these advances, key challenges remain, particularly in cellulose processing, electrochemical stability, and interfacial compatibility, which must be addressed to enable the development of fully bio-derived and efficient sodium-ion battery technologies. This review systematically identifies these findings and gaps, offering a PRISMA-guided and sodium-ion-specific roadmap for advancing cellulose-based materials toward practical and sustainable SIB technologies.