What are the differences between PP film and PE film for lithium battery separator?

Currently commercial lithium battery separators are mainly polyolefin microporous films, including polyethylene (PE) single-layer films, polypropylene (PP) single-layer films, and PP/PE/PP three-layer composite films. The melting point of the PP film and the PE film of the lithium battery separator are different. In terms of material chemistry, the two types of lithium battery separators have different melting points: PE separators are around 130°C, and PP separators are around 160°C. 1. Polyethylene (PE) is abbreviated as PE, which is a kind of thermoplastic resin made by polymerization of ethylene. In industry, it also includes copolymers of ethylene and a small amount of α-olefins. Polyethylene is odorless, non-toxic, feels like wax, has excellent low temperature resistance (the minimum use temperature can reach -70~-100℃), has good chemical stability, and can withstand most acids and alkalis (not resistant to oxidizing properties) It is insoluble in general solvents at room temperature, has low water absorption, and has excellent electrical insulation properties; however, polyethylene is very sensitive to environmental stress (chemical and mechanical uses) and has poor heat aging resistance. 2. The polymer PP material has lower thermal distortion temperature (100C), low transmittance, low gloss, low rigidity, but has stronger impact strength. The strength of PP increases with the increase in ethylene content. The Vicat softening temperature of PP is 150C. Due to the high crystallinity, the surface rigidity and scratch resistance of this material are very good. PP does not have the problem of environmental stress cracking. Usually, the PP is modified by adding glass fiber, metal additives or thermoplastic rubber. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete.