Green Synthesis of Citric Acid-Crosslinked Cellulose Acetate Membrane for Polymer Electrolyte

Safer alternative for lithium-ion battery containing liquid electrolyte was proposed using solid polymer electrolyte as a combo separator/electrolyte. In this work, cellulose acetate (CA) was used to replace fossil-based polymer as battery separator. To further promote sustainable membrane fabrication, dimethylsulfoxide (DMSO) and citric acid was used as solvent and cross-linking agent, respectively. Branched polyethyleneimine (bPEI) was also incorporated in the polymer electrolyte complex to promote electrolyte salt dissociation within the matrix. Crosslinking of CA-bPEI using citric acid showed promising properties compared to unmodified CA membrane. Better thermal stability and lower crystallinity were seen in the modified CA membrane, resulting in better ionic conductivity.