Tailoring the pore size of polyphenylene sulfide nonwoven with bacterial cellulose (BC) for heat-resistant and high-wettability separator in lithium-ion battery

Separator, a key component in lithium ion batteries (LIBs), is directly related to the cell performance and safety. So far, the widely used polyolefin separator has the defects of inferior electrolyte wettability, weak thermal tolerance and complex preparation process. Herein, we reported a new composite separator for lithium-ion battery through a facile papermaking method by employing the heat-resistant polyphenylene sulfide (PPS) fibers and the bacterial cellulose (BC) nanofibers (BC/PPS for short). Specifically, the BC nanofibers were used to regulate the pore size of the composite membrane. It was demonstrated that the hybrid BC/PPS separator showed remarkable thermal stability, good electrolyte wettability and prominent ionic conductivity. These advantages endow the cells using the composite separator with much better rate capability and more stable cycling performance than the cells with commercial separator. Therefore, the BC/PPS composite membrane reported here will plays a significant contribution to the development of separator for high power LIBs.