Brief introduction of lithium ion battery separator production process

The many characteristics of lithium-ion battery separators and the difficulty of taking into account its performance indicators determine the high technical barriers of the production process and the difficulty of research and development. The diaphragm production process includes many processes such as raw material formula and rapid formula adjustment, micropore preparation technology, and independent design of complete equipment. Among them, the micropore preparation technology is the core of the lithium-ion battery separator preparation process. According to the difference in the micropore formation mechanism, the separator process can be divided into two types: dry and wet. 1. Dry double drawing It is understood that the dry double drawing process is a process with independent intellectual property rights developed by the Institute of Chemistry, Chinese Academy of Sciences, and is also a unique diaphragm manufacturing process in my country. Because the β crystal form of PP is a hexagonal crystal system, single crystal nucleation and loose wafer arrangement. It has a lamellar structure that grows in a divergent beam shape along the radial direction and does not have a complete spherulite structure. Under heat and stress applications It will be transformed into a denser and more stable α crystal, and holes will appear in the material after absorbing a large amount of impact energy. In this process, a β-crystal modifier with nucleation purpose is added to PP, and the difference in density between different phases of PP is used to transform the crystal form to form micropores during the stretching process. 2. Wet asynchronous stretching technology The technological process of wet synchronous stretching technology is basically the same as that of asynchronous stretching technology, except that it can be oriented in both the horizontal and vertical directions at the same time during stretching. The uniformity of the diaphragm thickness is improved. However, the problem of synchronous stretching is that the speed of the vehicle is slow, and the second is that the adjustability is slightly worse. Only the transverse stretch ratio is adjustable, while the longitudinal stretch ratio is fixed. Disclaimer: Some pictures and content of articles published on this site are from the Internet, please contact to delete if there is any infringement. Previous: How to detect the performance of lithium ion batteries