What is the process of the soft-pack lithium-ion battery?

What is the process of the soft-packed lithium-ion battery? 1. Soft-packed batteries The soft-packed batteries are batteries that use aluminum-plastic film as the packaging material. The important packaging rheumatic heat packaging, the reason why laser welding is not used is that the packaging material of aluminum-plastic film is easier to encapsulate and shape than the outer packaging of steel or aluminum shell. 2. Aluminum-plastic packaging film Aluminum-plastic packaging film is actually aluminum-plastic film, which has a three-layer structure of nylon layer, AI layer and PP layer. Each layer has its corresponding purpose. The overall purpose of the aluminum-plastic packaging film is to protect the battery cell. The purpose of the AI u200bu200blayer is to prevent water infiltration. The nylon layer ensures that the shape of the aluminum-plastic film will not change, while the PP layer is actually heat-encapsulated. The material, PP, is polyethylene, which will melt and bond together under heating, and will solidify after cooling to achieve the purpose of encapsulation. 3. Aluminum-plastic film molding Aluminum-plastic film molding is a well-known process of mold opening and molding. This process is also called punching. Use the forming mold to punch out a pit capable of holding telecommunications under heating. 4. Top and side sealing process This process includes top sealing and side sealing. It should be noted that this process will leave an air bag opening for the next step of liquid injection. But the important thing is the top seal. The top seal is to seal the tabs. The tabs are made of metal (aluminum anode and nickel cathode). How can they be packaged with PP? This is done by a small part of the lug on the lug. The tab glue has the cost of PP, which means that it can be melted and bonded when heated. During packaging, the PP in the tab glue and the PP layer of the aluminum-plastic film melt and bond to form an effective packaging structure. Lithium-ion battery 5. Liquid injection and pre-sealing process After the top-side sealing process is completed, the liquid injection and pre-sealing processes must be carried out within the standing time. The liquid injection is very simple, that is, inject the electrolyte into the aluminum plastic film, and then Pre-package quickly (preliminary package, also called one). After the pre-sealing is completed, the inside of the cell is theoretically isolated from the outside. 6. After the completion of the fifth process of standing + forming + fixture shaping process, it is necessary to let the electrolyte fully infiltrate the pole piece by standing at high temperature and normal temperature, and then take the cell to be formed (equivalent to cell activation, Gas will appear again). Fixture shaping is actually because some factories use fixture formation, so that the formed electrode interface is better, but it has the disadvantage of deformation. The fixture shaping process is also called baking. 7. The second sealing process is due to the formation of gas, so there will be the second sealing process. In the second seal, the air bag is first pierced by a guillotine and the vacuum is drawn at the same time, so that the gas and a small part of the electrolyte in the air bag will be drawn out. Then immediately the second sealing head is encapsulated in the second sealing area to ensure the air tightness of the cell. Finally, cut off the air bag of the encapsulated cell, and a soft-packed cell is basically formed. 8. Follow-up process The follow-up process is trimming, disassembling, dividing (capacity test), checking appearance, pasting yellow glue, edge voltage testing, tab transfer welding, OQC inspection, packaging and shipping, etc. Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact to delete. Previous: The principle and wiring of lithium ion battery protection board