What are the methods of assembling soft-pack lithium batteries?

Soft-packed lithium battery packaging method Aluminum-plastic film forming process The soft-packed lithium battery can be designed into different sizes according to customer needs. When the external dimensions are designed, the corresponding mold must be opened to form the aluminum-plastic film. Sometimes, according to the design requirements, a small hole is punched in the position of the air bag to expand the volume of the air bag. Top-side sealing process The top-side sealing process is the first packaging process for soft-packed lithium batteries. The top side seal actually includes two processes, the top seal and the side seal. First put the wound core into the punched pit, and then fold the packaging film in half along the dotted line. After the core is placed in the pit, the entire aluminum plastic film can be placed in the fixture, and the top and side sealing are performed in the top side sealing machine. After the liquid filling and pre-sealing process, the soft-packed batteries are sealed on the top side, X-ray is required to check the parallelism of the cores, and then go into the drying room to remove moisture. After a certain period of time in the drying room, it enters the liquid injection and pre-sealing process. After the cell is sealed on the top side, there is only one opening on the air bag side, and this opening is used for liquid injection. After the liquid injection is completed, the pre-sealing of the side of the air bag should be carried out immediately, which is also called one. After a package is completed, the core is theoretically completely isolated from the external environment. After the process of standing, forming, and jig shaping is completed, the cells must first be left to rest. According to the different processes, they are divided into high temperature and normal temperature. The purpose of the standing is to make the injected electrolysis The liquid fully soaks the pole piece. Then the batteries can be used to make them. The chemical achievement is the first charging of the battery, but it will not be charged to the highest voltage used, and the charging current is also very small. The purpose of chemical conversion is to form a stable SEI film on the electrode surface, which is equivalent to a process of activating the cell. In this process, a certain amount of gas will appear, which is why the aluminum plastic film needs to reserve an air bag. After formation, some cells, especially thick cells, may undergo certain deformation due to large internal stress. Therefore, some factories will set up a fixture shaping process after the formation, which is also called fixture baking (baking). The second sealing process just said that there will be gas during the formation process, so we have to extract the gas and then carry out the second encapsulation. Some companies here have two processes: Degassing (exhaust) and two seals, and the latter process of cutting the air bag. Here I will call them two seals in general. In the second seal, the air bag is first pierced by a guillotine and a 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. The second seal is the last packaging process of the lithium battery, and its principle is still the same as the previous thermal packaging, so I will not repeat it. In the subsequent process, after cutting the air bag, trimming and folding should be carried out, which is to cut the one side and the second side to an appropriate width, and then fold them to ensure that the width of the battery does not exceed the standard. After folding, the battery cell can be installed in the capacity-dividing cabinet for capacity distribution. In fact, it is a capacity test to see if the capacity of the battery core has reached the specified minimum value. In principle, all batteries must be tested before leaving the factory to ensure that batteries with unqualified capacity will not be delivered to customers. However, when the processing volume of cells is large, some companies will make partial capacity, and use statistical probability to judge the qualified rate of the batch of cell capacity. After the capacity is divided, the cells with qualified capacity will enter the subsequent processes, including appearance inspection, yellow glue, edge voltage detection, tab transfer welding, etc. Several processes can be added or subtracted according to customer needs. The last is OQC inspection, and then packaged and shipped. 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: Policies and markets are favorable to promote the development of the power lithium-ion battery industry.