1. Technical difficulties of power battery welding
General power battery aluminum shell thickness requirements are up to 1.0 mm below, the mainstream manufacturers currently according to the battery capacity of different shell material thickness to 0.6mm and 0.8mm two main. Power battery aluminum shell thickness welding is mainly divided into side welding and top welding, and the main advantages of side welding is less impact for cells internal, the splash will not easily enter the inside of the shell cover.
As the welding may lead to bulging, which will have some minor impact on the assembly process of the follow-up process, the side of the welding process on the stability of the laser, material cleanliness and power cover with the battery cover with a higher gap . The top welding process due to welding on one side, can be more efficient galvanometer scanning welding, but the former procedure into the shell and positioning requirements, the requirements of the equipment automation are high.
2. power battery aluminum welding difficulties
At present the power battery aluminum shell accounts for the entire power battery 90% above. Aluminum laser welding is difficult, will face the weld surface convex problems, stomatal problems, fires, internal bubble problems. Surface protrusions, stomata, internal air bubbles are fatal to laser welding, and many applications have to stop or think of ways to circumvent them for these reasons.
There will be a lot of difficulties in the initial R&D, because the use of optical fiber core diameter is too small or laser energy set too high. There are many factors, such as cleanliness of material, purity of material itself, characteristics of material itself, and so on. The decisive effect is the stability of the laser.
In the power battery welding, the welding process technical personnel will be based on the customer's battery material, shape, thickness, tensile requirements and other appropriate laser and welding process parameters, including welding speed, waveform, peak, welding head tilt angle to set a reasonable Welding process parameters to ensure that the final welding results to meet the requirements of power battery manufacturers.