Lithium battery separator production process -Lithium - Ion Battery Equipment
The many characteristics of lithium-ion battery separators and the difficulty of taking into account their performance indicators determine the high technical barriers to their production processes and the difficulty of research and development. The production process of diaphragm includes many processes such as raw material formulation and rapid formulation adjustment, microporous preparation technology, and independent design of complete sets of equipment. Among them, the micropore preparation technology is the core of the lithium ion battery diaphragm preparation process. According to the difference in the micropore pore formation mechanism, the diaphragm process can be divided into two types: dry method and wet method.(Lithium - Ion Battery Equipment)
1. Dry double pull
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 it is also a unique diaphragm manufacturing process in my country. Since the β crystal form of PP is hexagonal, the single crystal nucleates and the wafers are loosely arranged. It has a lamellar structure that grows into a divergent bundle in the radial direction and does not have a complete spherulite structure. It is used in thermal and stress applications. It will transform into a more dense and stable α crystal, which will cause holes in the material after absorbing a lot of impact energy. In this process, a beta crystal modifier with nucleation purpose is added to PP, and the difference in density between different phases of PP is used to form micropores during the stretching process.
2. Wet asynchronous stretching process
The process flow of wet synchronous stretching technology is basically the same as that of asynchronous stretching technology, except that it can be oriented in both horizontal and vertical directions during stretching, which eliminates the need for separate longitudinal stretching and enhances the thickness uniformity of the diaphragm. However, the problems of synchronous stretching are that the speed of the vehicle is slow, and the adjustability is slightly poor. Only the horizontal stretching ratio is adjustable, and the longitudinal stretching ratio is fixed.
1. Dry double pull
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 it is also a unique diaphragm manufacturing process in my country. Since the β crystal form of PP is hexagonal, the single crystal nucleates and the wafers are loosely arranged. It has a lamellar structure that grows into a divergent bundle in the radial direction and does not have a complete spherulite structure. It is used in thermal and stress applications. It will transform into a more dense and stable α crystal, which will cause holes in the material after absorbing a lot of impact energy. In this process, a beta crystal modifier with nucleation purpose is added to PP, and the difference in density between different phases of PP is used to form micropores during the stretching process.
2. Wet asynchronous stretching process
The process flow of wet synchronous stretching technology is basically the same as that of asynchronous stretching technology, except that it can be oriented in both horizontal and vertical directions during stretching, which eliminates the need for separate longitudinal stretching and enhances the thickness uniformity of the diaphragm. However, the problems of synchronous stretching are that the speed of the vehicle is slow, and the adjustability is slightly poor. Only the horizontal stretching ratio is adjustable, and the longitudinal stretching ratio is fixed.
