What is the process of soft-pack lithium batteries? -Lithium - Ion Battery Equipment
What is the process of soft pack batteries?
1. Soft-packed batteries
To put it bluntly, soft-packed batteries are batteries that use aluminum-plastic film as packaging material. The main packaging used is rheumatic heat packaging. The reason why laser welding is not used is that the packaging material of aluminum plastic film is easier to package and form than the outer packaging of steel shell or aluminum shell.
2. Aluminum plastic packaging film
Aluminum-plastic packaging film is actually aluminum-plastic film, with 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 core. The purpose of the AI layer is to prevent water from penetrating. The nylon layer ensures that the shape of the aluminum-plastic film will not change. The PP layer is actually heat-sealed. Material, PP is polyethylene, which will melt and bond together under heating, and will solidify after cooling to achieve the purpose of encapsulation.(Lithium - Ion Battery Equipment)
3. Aluminum plastic film molding
Aluminum plastic film forming is a process that everyone is familiar with. This process is also called pit punching. A mold is used to punch out a pit that can hold telecommunications while being heated.
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 filling. But the important thing to talk about is the top seal. The top seal is to seal the tabs. The tabs are metal (positive aluminum, negative nickel). How can they be packaged together with PP? This is accomplished by the lug glue, a small component on the lug. The cost of the tab glue is PP, which means it can melt and bond when heated. During packaging, the PP in the tab glue and the PP layer of the aluminum-plastic film melt and bond, forming an effective packaging structure.
5. Liquid injection and pre-sealing process
After completing the top and side sealing process, the liquid injection and pre-sealing processes must be carried out during the standing time. The liquid injection is very simple, that is, injecting the electrolyte etc. into the aluminum-plastic film, and then quickly pre-sealing (preliminary packaging, also called one letter). After the pre-sealing is completed, the inside of the battery cell is theoretically isolated from the outside.
6. Resting + forming + fixture shaping process
After the fifth process is completed, it is necessary to let the electrolyte fully infiltrate the pole pieces through high temperature and normal temperature, and then take the battery core to form it (which is equivalent to activating the battery core, and gas will appear again). Clamp shaping is actually because the process of some factories will use clamps to form the electrodes. This way the formed electrode interface will be better, but there will be the disadvantage of deformation. The clamp shaping process is also called baking.
7. Second sealing process
Because gas is produced during the formation, there is a second sealing process. During the second sealing, the air bag is first punctured with a guillotine and vacuumed at the same time, so that the gas and a small part of the electrolyte in the air bag will be extracted. Then the second sealing head is immediately sealed in the second sealing area to ensure the airtightness of the battery core. Finally, the air bag is cut off from the packaged battery core, and a soft-packed battery core is basically formed.
8. Subsequent processes
The follow-up processes are trimming, removing edges, dividing capacity (capacity test), appearance inspection, yellow glue application, edge voltage detection, tab transfer welding, OQC inspection, packaging and shipping, etc.
1. Soft-packed batteries
To put it bluntly, soft-packed batteries are batteries that use aluminum-plastic film as packaging material. The main packaging used is rheumatic heat packaging. The reason why laser welding is not used is that the packaging material of aluminum plastic film is easier to package and form than the outer packaging of steel shell or aluminum shell.
2. Aluminum plastic packaging film
Aluminum-plastic packaging film is actually aluminum-plastic film, with 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 core. The purpose of the AI layer is to prevent water from penetrating. The nylon layer ensures that the shape of the aluminum-plastic film will not change. The PP layer is actually heat-sealed. Material, PP is polyethylene, which will melt and bond together under heating, and will solidify after cooling to achieve the purpose of encapsulation.(Lithium - Ion Battery Equipment)
3. Aluminum plastic film molding
Aluminum plastic film forming is a process that everyone is familiar with. This process is also called pit punching. A mold is used to punch out a pit that can hold telecommunications while being heated.
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 filling. But the important thing to talk about is the top seal. The top seal is to seal the tabs. The tabs are metal (positive aluminum, negative nickel). How can they be packaged together with PP? This is accomplished by the lug glue, a small component on the lug. The cost of the tab glue is PP, which means it can melt and bond when heated. During packaging, the PP in the tab glue and the PP layer of the aluminum-plastic film melt and bond, forming an effective packaging structure.
5. Liquid injection and pre-sealing process
After completing the top and side sealing process, the liquid injection and pre-sealing processes must be carried out during the standing time. The liquid injection is very simple, that is, injecting the electrolyte etc. into the aluminum-plastic film, and then quickly pre-sealing (preliminary packaging, also called one letter). After the pre-sealing is completed, the inside of the battery cell is theoretically isolated from the outside.
6. Resting + forming + fixture shaping process
After the fifth process is completed, it is necessary to let the electrolyte fully infiltrate the pole pieces through high temperature and normal temperature, and then take the battery core to form it (which is equivalent to activating the battery core, and gas will appear again). Clamp shaping is actually because the process of some factories will use clamps to form the electrodes. This way the formed electrode interface will be better, but there will be the disadvantage of deformation. The clamp shaping process is also called baking.
7. Second sealing process
Because gas is produced during the formation, there is a second sealing process. During the second sealing, the air bag is first punctured with a guillotine and vacuumed at the same time, so that the gas and a small part of the electrolyte in the air bag will be extracted. Then the second sealing head is immediately sealed in the second sealing area to ensure the airtightness of the battery core. Finally, the air bag is cut off from the packaged battery core, and a soft-packed battery core is basically formed.
8. Subsequent processes
The follow-up processes are trimming, removing edges, dividing capacity (capacity test), appearance inspection, yellow glue application, edge voltage detection, tab transfer welding, OQC inspection, packaging and shipping, etc.
