A Short Review and Future Prospects of Biomass-Based Solid Polymer Electrolytes for Improving the Performance of Lithium Metal Batteries

The development of biomass-based solid polymer electrolytes (SPEs) as a desirable alternative to traditional organic liquid electrolytes and separators is crucial to advancing sustainable, safer, and high-performance lithium batteries. Biomass is a natural polymer with the advantages of biodegradability, low cost, and abundant availability. However, low ionic conductivity remains a major drawback limiting its commercial applications. Therefore, many literatures have reported the enhancement of ionic conductivity and mechanical stability of SPEs by chemically modifying biomass with various functional groups and composite structures. This review summarizes the structural features, physicochemical properties and different types of biomass derivatives, as well as recent advances in the field of biomass-based SPEs. Finally, we propose an outlook on the future development of cellulose-based SPEs for lithium metal batteries (LMBs).