Performance requirements of lithium-ion battery separator materials and the development trend of materials

The performance requirements of lithium-ion battery separator materials are lithium-ion battery separators as one of the four important materials for lithium-ion batteries. Generally, they are materials with good insulation properties and provide migration channels for lithium ions in the electrolyte. The performance parameters of the diaphragm have a significant impact on the performance of the battery, so the preparation of high-performance diaphragm materials is very important for the performance and practical application of the battery. Important factors affecting the performance of lithium-ion battery separators include the chemical stability of the separator, mechanical strength, porosity and wettability, and self-closing performance for safety protection. 1. Mechanical strength The diaphragm must have a certain mechanical strength in the structure of the lithium ion battery and the process of charging and discharging reactions. An important purpose of the diaphragm is to separate the positive and negative reactions. If the diaphragm shrinks or ruptures and the electrolyte penetrates, a short circuit of the battery will occur, which poses a great safety hazard. Therefore, the diaphragm must have a certain degree of mechanical strength and toughness. 2. Thermal Polarity Since the electrolyte solution in lithium ion batteries uses organic solvents and non-aqueous electrolytes in addition to water solvents, the separator should have good chemical stability and corrosion resistance, and be able to charge and discharge the battery many times. Achieve structural integrity and reaction stability. 3. Pore distribution and porosity In order to maintain good lithium ion permeability, the material must have pores of a certain size, and ensure low resistance and high ion conductivity. The pore size will affect the internal resistance of the battery and the safety of the battery. 4. Battery safety In addition, the self-closing technology of the diaphragm is very important in terms of battery safety. The self-closing mechanism requires the diaphragm to release a lot of heat when overloaded, and the temperature rises too high. The pores in the diaphragm structure close when it is close to the melting point of the material, successfully isolate the ion shuttle, stop the positive and negative reactions to form a circuit, to prevent the battery from exploding under overheating. 5. Wetability The wettability of the lithium ion battery diaphragm is also one of the criteria for evaluating the performance of the diaphragm. In order to ensure the smooth transmission of ions, the diaphragm must be in full contact with the electrolyte, and it has good wettability, and the ability to penetrate the electrolyte. Ion penetration capability. The development trend of lithium-ion battery separator materials Lithium-ion battery separators have become one of the key materials for the production of lithium-ion batteries, and even an important part of its industrial chain. Because the production process of the diaphragm has a high technical barrier, its cost accounts for about 10%-20% of the cost of lithium-ion batteries, and the gross profit rate can reach 50%-60%. It is the product with the highest gross profit rate among the four important materials. Therefore, , Lithium-ion battery separators are also considered by the industry as one of the most valuable industries in the lithium-ion battery industry chain. The production of lithium-ion battery separator materials has been expanding. In order to meet market demand and enhance competitiveness, Xingyuan Materials is also actively expanding production. At present, Shengli Precision's new energy business includes lithium-ion battery wet membrane and smart car manufacturing business, namely the production, research and development of lithium-ion battery wet membrane and the production and manufacturing of smart car core structural modules. It mainly supplies wet base films and coatings. Products such as the structural parts of the film and the central control display module. In the future, competition in the lithium-ion battery separator industry will intensify. In 2019, my country's lithium-ion battery separator production has reached 1.435 billion square meters; as the new production is gradually put into production, my country's lithium-ion battery separators may experience a serious oversupply situation; at that time , The market competition of lithium-ion battery separators will further intensify, and fierce price wars may be unavoidable. At that time, only those companies with core technology, strong Ru0026D capabilities and excellent financial performance can win and grow stronger in the fierce competition, while the rest of the companies can only be eliminated and exited. 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 article: How is the internal resistance of a lithium ion battery composed