Power lithium battery diaphragm technology -Lithium - Ion Battery Equipment
The main performance requirements of the current lithium battery separator are: thickness uniformity, mechanical properties (including tensile strength and puncture resistance), air permeability, physical and chemical properties (including wettability, chemical stability, thermal stability, safety), etc. Four performance indicators.(Lithium - Ion Battery Equipment)
The technical development of lithium battery separators is advancing with the changes in the application of lithium ion batteries. The current prominent feature is the development trend of lithium batteries becoming smaller and larger and lithium batteries becoming larger and larger.
From the "small" perspective
It is mainly reflected in lithium batteries for portable electronic consumer products, such as mobile phones, digital cameras, electronic dictionaries, etc. The high energy density requirements for the design of lithium batteries due to aesthetics and miniaturization have prompted the diaphragms for such lithium battery applications to be thinner and 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 diaphragm is inevitable, which requires that the diaphragm is thinner to maintain the original Some battery capacity and cycle life.
From the "big" perspective
It is mainly reflected in the lithium power 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 the current bottleneck restricting power lithium batteries. There are three main reasons for this:
1. Safety is the core of the physical and chemical properties of lithium-ion battery separators, and any defect in the other three properties may lead to unstable safety performance;
2. The larger the capacity of the single cell of the power lithium battery itself, the less the number of cells that need to be connected in series. This objectively requires the power lithium battery to use a cell with a larger capacity. Performance indicators require more delicate processes to ensure;
3. Since the consistency and combination technology of series cells will bring security risks, it is especially necessary to manufacture lithium battery separators more precisely.
The excellent performance of lithium batteries and lithium battery packs cannot be completely expected from a piece of separator. The full matching of positive and negative electrodes and electrolyte components can achieve this goal. Lithium battery packs have more technical problems of combination. However, the importance of separator technology as the most valuable lithium battery technology is self-evident.