Surface-modified polyethylene separator via oxygen plasma treatment for lithium ion battery

Abstract The separator is an important component in lithium ion batteries (LIBs). However, commercial separators such as polyethylene (PE) and polypropylene (PP) are in urgent need to be modified to improve the surface properties to meet requirements for high performance LIBs. In this study, oxygen plasma has been applied to modify the surface of PE separating membrane with functional groups, which has greatly improved the electrolyte wettability and retention of PE separators. The cells with plasma-treated PE separators showed improved charge–discharge capability with lower interfacial resistance and stable cycling performance. This result demonstrates a high potential of the plasma-treated PE separator in LIBs.