Advances in research and industrial technology of lithium ion battery separator

The separator plays very important role in the lithium ion batteries preventing electric contact of electrodes but permeable to ionic flow. This article reviews the recent progress in LIB separator research and related industrial technology. Two issues, how to build a thermal-resistant separator and how to improve ionic conductivity of the separator, are focused. This review includes four parts: the factors affecting separators' performance, gel polymer electrolyte, separators produced by stretching method and its modification, new methods and new materials in LIB separator fabrication. Finally, the challenges and prospects related to LIB separators are summarized.