Cellulose-based solid and gel polymer electrolytes with super high ionic conductivity and charge capacity for high performance lithium ion batteries

Polymer electrolytes are one of the most effective alternatives to liquid electrolytes to extend lithium ion batteries (LIBs) safety. However, they suffer from low conductivity and charge capacity. In this work, to overcome these tremendous disadvantages, cellulose acetate (CA) and oxidized carboxymethyl cellulose (OCMC) polymer electrolytes obtained from sugarcane and cotton, respectively, are used as polymer electrolytes in LIBs. Then, the effect of short (citric acid) and long (polyvinyl alcohol (PVA)) chain crosslinker to create polymer networks and solid and gel state of electrolytes on the electrochemical properties are investigated. Gel CA-PVA and solid OCMC-PVA electrolytes indicated the best results. Additionally, each CA and OCMC, in both gel and solid state exhibited ionic conductivity in order of 10−2 S cm−1, charge capacity over 230 mAh g−1, capacity retention of 90% after 100 cycles, excellent electrochemical stability upper than 4.5 V, supreme lithium transfer number (∼ 0.8), and good thermal stability. The electrolytes prepared here bring safe and highly efficient LIBs and are a very serious competitor to liquid electrolytes.