The "big" and "small" of domestic power lithium-ion battery diaphragm technology

my country's lithium-ion battery industry is in the ascendant. Under the encouragement of national policies, the current production expansion and potential production development are doubling year by year. As the most profitable separator in the inner layer of lithium-ion batteries, it is the first to develop.



The current critical performance requirements of lithium-ion battery separators include: thickness average, mechanical properties (including tensile strength and puncture resistance), air permeability, physical and chemical properties (including wettability, chemical stability, thermal stability, and safety) Four major performance indicators.



The technological development of lithium-ion battery separators is advancing with the changes in the use of lithium-ion batteries. At present, the prominent feature is the development trend of terminalization of lithium-ion batteries becoming smaller and lithium-ion batteries becoming larger.



From the "small" point of view



The important thing is that lithium-ion batteries used in portable electronic consumer products, such as mobile phones, digital cameras, electronic dictionaries, etc., are beautiful and miniaturized. The high energy density requirements for the design of lithium-ion batteries have prompted more and more separators for such lithium-ion batteries. The thinner. Because the meaning of high energy density is to accommodate more electrode materials in a small volume, under the condition that the positive and negative materials have been determined, the performance of the separator becomes inevitable. This requires that the separator be thinner to maintain the original Some battery capacity and cycle life.



From the "big" point of view



In terms of the current lithium-powered lithium-ion batteries used in electric bicycles and electric vehicles, it is not difficult to see through the spontaneous combustion incidents of electric vehicles exposed in China that safety performance is currently the bottleneck restricting power lithium-ion batteries. The important reasons for this are the three aspects of the present:



1. Safety is the core of the physical and chemical properties of lithium-ion battery separators. Any defect in the other three properties may lead to unstable safety performance;



2. The larger the capacity of the power lithium-ion battery cell itself, the fewer the number of cells to be connected in series. This objectively requires the power lithium-ion battery to use a cell with a larger capacity. The performance indicators of the core should be guaranteed by a more delicate process;



3. Due to the consistency of the series battery cells and the combination technology will bring safety hazards, this especially requires the manufacture of lithium-ion battery separators to be more precise.



Can the superiority of lithium-ion batteries and lithium-ion battery packs be completely counted on the diaphragms, and the full matching of the positive and negative electrodes and electrolyte components can achieve this goal? Li-ion battery packs have even more combined technical problems. However, the importance of diaphragm technology as the most valuable lithium-ion battery technology is self-evident.