Battery laser welding technology and traditional welding technology advantages and disadvantages

Energy power battery management module can be used as the core of the key issues of new energy vehicles, not only related to the vehicle s driving performance, ...

Aug 31,2023 | Joyce

Energy power battery management module can be used as the core of the key issues of new energy vehicles, not only related to the vehicle's driving performance, but also related to the user's car safety culture experience. Promote new energy lithium battery battery industry to realize the full popularization of automated laser welding production line is the strategic goal of the major laser.battery pilot line Laser welding production technology can make perfect use of the laser beam of various resources to analyze the advantages of the welding task, in the future, the laser welding construction technology will be more flexible to adapt to the society of different new energy power battery materials, different shapes of the demand for lithium battery module welding task. Will be our future manufacturing industry urgently needed emerging welding technology.

1. Conventional welding lithium battery technology defects

The conventional welding of power lithium batteries is mainly manual welding and gas welding. In the welding process, it is necessary to continuously fill the welding joint with protective gas to ensure the quality of welding.laser welding machine for lithium ion batteries This process is manually pressure held by workers, the size of which is often difficult to control, the quality of the assembly is uneven, and it will also bring unnecessary trouble to the lithium battery assembly and encapsulation system of the later matching process.

At the same time, manual pressure welding not only affects the production efficiency, but also in the welding process there are hidden dangers, which may lead to the welding of the battery shell after the internal connection loosening, in the actual application is bound to threaten the safety of driving.

2. Laser welding lithium battery technology advantages

Compared with the traditional welding production technology, the laser by virtue of its high energy density, convergent beam after the column propagation of information is not easy to exhaust the unique advantages of the welding heat-affected zone of the metal metallurgical changes in the study of a smaller range, and secondly, through the laser welding method belongs to the non-contact welding, welding completion of the operation will not produce its own electrode material contamination, machine loss and other issues, but also improve the adaptability of the different species of lithium battery shell solder; and at the same time, the laser welding process is a hidden danger, which may lead to the welding of the internal connection of the battery shell.ESS lithium battery machine Lithium battery shell solder; at the same time, the welding mouth deformation is smaller, welding speed, high precision, but also easier to manage to realize China's automation.

In practical applications, laser welding battery protection shell or small diameter wiring channel is not subject to the limitations of delayed melting. Therefore, the weld is smooth, the weld channel is beautiful and neat, the weld is not easy to penetrate, the metal internal defects are small, saving the subsequent re-processing process, reducing additional production costs.

3. Laser welding process difficulties

At present, the battery shell made of aluminum alloy accounts for more than 90% of the entire power battery aluminum. The difficulty of welding lies in the high reflectivity of aluminum alloy to laser light, and the high sensitivity of air holes during welding. The most important ones are porosity, thermal cracks and explosion.

Aluminum alloys are prone to porosity during laser welding, which is mainly caused by hydrogen porosity and bubble rupture. Hydrogen porosity is a growing problem due to the rapid cooling rate of laser welding.

Thermal cracking problem. Aluminum alloy is a typical eutectic alloy, which is prone to thermal cracking during welding. This includes weld crystallization cracks and HAZ liquefaction cracks. The segregation of the weld zone composition leads to eutectic segregation, grain boundary melting, and grain boundary liquefaction cracking under stress, which reduces the performance of the welded joint.

Spatter Problems. Factors causing spatter lead to many, for example through the cleanliness of the material, the purity of the material technology itself, the properties of the material itself, etc. Playing a decisive role in influencing is the stability of the laser. The surface of the housing is uneven, air holes, and internal control bubbles. The reason is mainly because the fiber core diameter is too small or the laser energy can be set too high. It is not the case that "the better the beam quality, the better the welding job", as some of our research laser equipment management suppliers advertise, but rather that good beam quality is suitable for superposition welding with a large depth of fusion. Using the right process design parameters is the best way to effectively solve the problems of the actual welding environment.

cell aluminum alloy lithium ion technology