What are the requirements for the important performance of lithium battery separators?

There are also requirements for the important performance of lithium battery separators, which are important in the following aspects: 1. Physical and chemical properties, wettability and wetting speed, better wettability is beneficial to improve the charge and discharge performance and capacity of batteries. Chemical stability, the diaphragm should maintain long-term stability in the electrolyte and not react with the electrolyte and electrode materials. Thermal stability, when the temperature rises, the diaphragm should maintain the original integrity and certain mechanical properties. Safety protection performance The safety of lithium batteries has become the most important link for lithium battery manufacturers. 2. Thickness uniformity The thickness uniformity of the lithium battery separator directly affects the appearance quality and the internal performance of the separator roll. The thickness uniformity of the separator includes longitudinal thickness uniformity and lateral thickness uniformity. Among them, the lateral thickness uniformity is particularly important. It is generally required to be controlled within ±1 micron. 3. Permeability The permeability of the diaphragm is the result of the comprehensive factors affecting the internal pore structure of the diaphragm, such as the porosity, pore size, pore shape and pore tortuosity of the diaphragm. The lithium battery separator itself has a microporous structure, and the distribution of micropores in the entire separator material should be uniform. The pore size is generally 0.03μm～0.12μm. If the pore size is too small, resistance will be added, and if the pore size is too large, it will easily make the positive and negative poles contact or be short-circuited by dendrites. 4. Mechanical properties. Tensile strength generally means that the longitudinal strength must reach more than 100mP, and the transverse strength should not be too large. If it is too large, the transverse shrinkage will increase. Puncture resistance: Because 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 degree of puncture resistance. According to relevant experience, the value of puncture resistance is between 300 and 500 grams. Disclaimer: Some pictures and content of articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: What are the important advantages of lithium batteries?