The separation materials on the market are mainly polyolefin (polyolefin) separators based on polyethylene (PE) and polypropylene (PP). Among them, PE products are mainly made by wet process, PP products are mainly made by dry process. As for the characteristics of the two materials, PE and PP.
In general:
①PP is relatively more resistant to high temperatures, and PE is relatively resistant to low temperatures;
②PP has a lower density than PE;
③PP The melting point and temperature of closed cell are higher than those of PE;
④PP products are more fragile than PE
⑤PE is more sensitive to environmental stress.
The main products of separation materials include single-layer PP, single-layer PE, PP+ceramic coating, PE+ceramic coating, double-layer PP/PE, double-layer PP/PP andthe triple layer coating. PP/PE/PP etc. Among them, the former two types of products are mainly used in the field of 3C small batteries, and the latter types of products are mainly used in the field of power lithium batteries. Among the separation materials for lithium electric batteries, double-layer PP/PP separation materials are mainly produced by Chinese enterprises and used in mainland China. This is mainly because at this stage no Chinese company can process PP and PE into double-layer composite films. . Technology and capabilities. The separators used in global automobile lithium batteries are mainly three-layer PP/PE/PP, double-layer PP/PE, PP+ceramic coatings, PE+ceramic coatings and other separator material products. At the same time, other new separator material productsrs are also emerging and beginning to be applied. However, due to small quantities and high prices, they are mainly used in the field of lithium battery manufacturing. These products mainly include: coated polyester film (PET, Polyethylene Terephthalate), cellulose film, polyimide film (PI), polyamide film (PA), spandex or aramid film, etc. The advantages of these separators are high temperature resistance, low temperature output, long charge cycle life and moderate mechanical strength. Overall, lithium battery separation material products show an obvious diversified development trend.