Manufacturing requirements for lithium-ion battery separators

Lithium battery separator is an important part of lithium ion battery and an important component that supports lithium ion battery to complete the electrochemical process of charging and discharging. 1. Lithium battery diaphragm function Lithium ion battery consists of four main parts: positive electrode material, negative electrode material, diaphragm, and electrolyte. Among them, the separator is a kind of film with a microporous structure, which is the key inner component of the most technical barrier in the lithium-ion battery industry chain. It plays the following two main roles in the lithium battery: a. Separating the positive of the lithium battery , Negative electrode, to prevent the positive and negative electrodes from contacting to form a short circuit; b. The micropores in the film can allow lithium ions to pass through, forming a charge and discharge circuit. 2. The basic materials of lithium battery diaphragm manufacturing materials: polyethylene (PE) diaphragm, polypropylene (PP) diaphragm, polyethylene (PZ) and propylene (PP) composite multilayer microporous film; product type: single-layer PP web, Single-layer PE film, double-layer PP/PE film, multi-layer film 3, lithium-ion batteries have requirements for separators including: (1) Electronic insulation to ensure the mechanical separation of the positive and negative electrodes; (2) A certain pore size and Porosity ensures low resistance and high ion conductivity, and has good permeability to lithium ions; (3) It is resistant to electrolyte corrosion and has sufficient chemical and electrochemical stability. This is due to the fact that the solvent of the electrolyte is Strongly polar organic compounds; (4) It has good electrolyte wettability and strong liquid absorption and moisturizing ability; (5) High mechanical stability, including puncture strength, tensile strength, etc., but the thickness is as small as possible; ( 6) Good dimensional stability and smoothness; (7) Good thermal stability and automatic shutdown protection performance; (8) Small thermal shrinkage, otherwise it will cause a short circuit and cause thermal runaway of the battery. In addition, power batteries usually use composite membranes, which have higher requirements for separators. 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 advantages and disadvantages of lithium iron phosphate batteries