Laser welding can greatly improve the safety and service life of power batteries

Laser welding can greatly improve the safety and service life of power batteries. In the manufacturing process of power batteries, laser welding has many parts, including tabs, flip sheets, seals, bus bars, PACK modules, injection hole packaging, etc., which can realize battery series and parallel. At the same time, it involves batteries, modules, packaging, and can also weld steel, aluminum, copper, nickel and other materials. The advantage of laser welding is that it effectively improves the reliability of the connection, facilitates the light weight of the module, reduces the battery resistance, and reduces its own heat loss. At the same time, the continuous work cannot be stopped, the welding quality is good, and the flexibility is high. The difficulty and pain point is that the assembly precision of the welded parts is high, and the position of the beam on the workpiece cannot be significantly shifted. At the same time, the cost of lasers and related systems is relatively high. There are two main types of laser welding for prismatic batteries: deep penetration welding and pulse welding. On the soft package battery, it is pulse welding. The principle is to weld high-energy-density laser components with a heat source, which has good reliability, low contact resistance, and high degree of automation, which can greatly improve production efficiency. At present, manufacturers of lithium laser welding equipment are in the market, such as Da Zu Maotang Laser, Hai Mu Xing, Xuan Shuo Zhi, Tide Laser, Sike Qi, Xin Intelligent, etc., among which the market share of Han's Laser, Hai Mu Xing, etc. Head companies such as Messing account for about 3040% of the market. At the same time, well-known lithium battery companies such as CATL, BYD, Guoxuan Hi-Tech, Yiwei Lithium Energy, Panasonic, and Samsung have all participated in the use of laser welding. Among the laser welding processes, sealing nail welding, cap welding, and continuous welding are prominent. Sealing nail welding is pulse welding, because the heat input is intermittent, and there is less tin and hydrogen, and the effect is good. The development of sealing nail welding is divided into two stages, the first stage is 7-8mm/s, the second stage is that the speed has reached 30mm/s, and it will be faster in the future. The first stage is the top cover welding, which can only be carried out at a speed of 60-80mm/s. Due to deep penetration welding, sight holes are easy to appear during the welding process, and the ends of the sight holes are easy to close. How does the electronic vapor leak out, and it is easy to cause surface roughness. The second stage is the commonly used hybrid welding and high-frequency swing welding, which can solve the problem of fast closing of the sight hole and greatly increase the welding speed. The third stage is when some companies start new attempts. For example, high-speed round spot welding and hybrid welding can reach 300mm/s. Continuous welding is characterized by fast speed, but it is easy to form heat accumulation, and there is no micro fracture during the instantaneous cooling of the molten pool. Continuous laser welding can reach 15mm/s, physical welding can reach 300mm/s. Generally speaking, laser head and galvanometer laser processing head welding are commonly used in lithium battery equipment, which can realize high-speed welding of complex trajectories such as s-shaped and spiral. Increase the welding strength while increasing the weld area. During the welding process, it can also be connected to the MES system to record and adjust various welding parameters in real time to ensure more stable welding and higher quality. Disclaimer: The articles published on this site are from the Internet and do not represent the views of this site. If there is any infringement, please contact to delete WeChat: Disclaimer: Some pictures and content of the articles published on this site are from the Internet. If there is any infringement, please contact delete A: These six points are the main culprits that damage the battery life of electric bicycles