Evaluation of PBI Nanofiber Membranes as a High-temperature Resistance Separator for Lithium-ion Batteries

Separators with excellent thermal stability and electrolyte wettability are essential for high-energy-density lithiumion batteries (LIBs). In this study, polybenzimidazole (PBI) nanofiber membranes were prepared by electrospinning and subsequent thermal calendering for a high-temperature resistance and flame-retardant LIB separator. The PBI nanofiber membrane calendered at 120 oC (PBI-120) was evaluated as an LIB separator due to its overall good physical properties. PBI- 120 showed better thermal dimensional stability, electrochemical stability, ionic conductivity, and interfacial compatibility with the electrodes than did a commercial separator, Celgard 2400. The cell assembled with PBI-120 showed stable chargedischarge profiles and cycle performance. The PBI nanofiber separator was demonstrated to be a promising separator candidate for enhanced safety and electrical performance of high-energy-density LIBs.