Review on current development of polybenzimidazole membrane for lithium battery

With the rapid development of portable technology, lithium batteries have emerged as potential candidates for high-performance energy storage systems owing to their high energy density and cycling stability. Among the key components of a lithium battery system, the separator plays a critical role as it directly influences the battery performance benchmark (cycling performance and safety). However, traditional polyolefin separators (polypropylene/polyethylene) are unable to meet the demands of high-performance and safer battery systems due to their poor electrolyte compatibility, thermal runaways, and ultimate growth of dendrites. In contrast, membranes fabricated using polybenzimidazole (PBI) exhibit excellent electrolyte wettability and outstanding thermal dimensional stability, thus holding great potential as separators for high-performance and high-safety batteries. In this paper, we present a comprehensive review of the general requirements for separators, synthesis technology for separators, and research trends focusing PBI membranes in lithium batteries to alleviate the current commercial challenges faced by conventional polyolefin separators. In addition, we discuss the future development direction for PBI battery separators by considering various factors such as production cost, ecological footprint, preparation technology, and battery component compatibility. By exploring these perspectives, we aim to promote the continued application and exploration of PBI-based materials to advance lithium battery technology.