Introduction Important performance requirements of lithium ion battery separator

Important performance requirements for lithium-ion battery separators With the promotion of new energy vehicles, the lithium-ion battery market has begun to expand. As the core material of lithium-ion batteries, membrane performance directly affects the capacity, cycle performance and safety performance of the battery. In industrial production, the important performance requirements for lithium ion battery separators are as follows: 1. Thickness uniformity The uniformity of the thickness of the lithium ion battery diaphragm directly affects the external quality and internal performance of the diaphragm coil. Film thickness uniformity includes longitudinal thickness uniformity and lateral thickness uniformity. The horizontal thickness uniformity is particularly important. It is generally required to be within ±1 micron. 2. Mechanical properties Tensile strength generally means that the longitudinal strength should reach 100mP or more, and the transverse strength should not be too large, too large will lead to an increase in the transverse shrinkage rate. Since the diaphragm is sandwiched between the uneven positive and negative plates, it has to withstand a lot of pressure. In order to prevent short circuits, the diaphragm must have a certain breakdown resistance. According to relevant experience, the puncture resistance value is between 300-500 grams. 3. The permeability of the magnetic permeability diaphragm is the result of comprehensive factors such as porosity, pore size, pore shape and pore curvature. The lithium ion battery membrane itself has a microporous structure, and the distribution of micropores in the membrane material should be uniform. The aperture is generally between 0.03km2 and 0.12km2. If the aperture is too small, resistance will be added. If it is too large, it will easily make the anode and cathode contact or be pierced and short-circuited by dendrites. 4. Physical and chemical properties of wettability and wetting speed, better wettability is conducive to improving the charge and discharge performance and capacity of the battery. Chemical stability. The membrane should remain stable for a long time in the electrolyte and should not react with the electrolyte and electrode materials. The thermal stability is good. When the temperature rises, the diaphragm should maintain the original integrity and certain mechanical properties. The safety of lithium-ion batteries has become the most important link for lithium-ion battery manufacturers. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What are the important applications of power lithium-ion batteries?