Vertical channel-structured cyanoethylated bacterial cellulose/polyethylene oxide composite solid electrolyte for all-solid-state lithium batteries

Solid polymer electrolytes (SPEs) have gained remarkable development within the realm of new energy resources. With its improved electrochemical stability and environmental-friendly sustainability, bacterial cellulose (BC) has emerged as a promising candidate for applications in SPEs. Herein, bacterial cellulose was chemically cyanoethylated and integrated with lithium bis(trifluoromethanesulphonyl)imide/polyethylene oxide (PEO) based SPE. Some vertical channels are formed when trace amounts (0.5 wt%) of cyanoethylated bacterial cellulose (BC-CN) are added to PEO-based SPE, as revealed by SEM. This formula's corresponding PEO-based SPE presents the highest ion conductivity of 5.7 x 10-4 S cm-1 at 60 degrees C. The ion migration activation (Ea) deduced from the Arrhenius equation is 0.48 eV, lower than the value of 0.82 eV for the pristine PEO SPE. Besides, the Li+ migration number of this modified PEO-based solid electrolyte is calculated to be a relatively high value of 0.33, while that of its counterpart, the pristine PEO SPE, is as low as 0.06. The all-solid-state lithium battery with PEO/0.5%BC-CN SPE can operate stably for 115 cycles, which is longer than the 80 cycles achieved with the pristine PEO SPE. This study introduces a novel strategy for creating modified BC composites PEO-based SPE.Highlights Bacterial cellulose was chemically cyanoethylated. Cyanoethylated bacterial cellulose composite polyethylene oxide (PEO)-based solid polymer electrolytes (SPEs) are prepared in DMF. Opening pores penetrate the surface of the PEO/0.5% cyanoethylated bacterial cellulose (BC-CN) SPE membrane. PEO/0.5% BC-CN shows ionic conductivity of 5.7 x 10-4 S cm-1 at 60 degrees C. Full cell with PEO/0.5% BC-CN performs stably for 115 cycles. The vertical-channel structure in PEO/0.5%BC-CN influences the performance of SPE. image