Efficient precision laser welding can greatly improve the car battery safety, reliability and service life, will bring progress to revolutionize the future of automotive power technology. Laser welded parts more battery power, there is pressure and leak test requirements, the majority of material is aluminum, the welding difficult, higher welding process requirements.
In general, the welding power battery case mainly top side welding and welding in two ways, they have their own advantages and disadvantages, and aluminum battery because of the special nature of the material, it is easy to bump, porosity, fraud or other problems square battery welding prone to problems around the corner.
Technical Difficulties battery welding
Usually shell thickness of 1.0 mm or less are required, according to the current mainstream manufacturers of battery capacity shell material thickness of 0.6mm and 0.8mm two kinds based. Welding is divided into a top and side welding welding, which mainly benefits the smaller side welding on internal batteries, spatter not easily enter the inside of the cover. Because after welding may lead to projections, the assembly will have a slight impact on this follow-up process, so the side with the laser welding process stability, cleanliness and roof material and the housing gap have higher requirements. And the top welding process since the welding on one side, can be more efficient galvanometer scan welding, but before the procedure into the shell and positioning demanding requirements of high automation equipment.
Aluminum battery welding Difficulties
Aluminum battery currently more than 90% of the entire battery. Laser welding of aluminum greater difficulty, will face the question raised surface welding marks, pores issues, fried fire problem, internal bubble problems. Convex surface, porosity, laser welding inside the bubble is fatal to many applications these reasons have to find a way to stop or avoid. Many battery manufacturers in the early development are a big headache for this reason, is mainly used in the fiber core diameter is too small or too high due to the laser energy setting. Factors causing fire fried (also known as splash, Splash) there are many, such as cleanliness, the purity of the material itself, the material properties of the material itself, etc., the sky a decisive role is the stability of the laser. In battery welding among the welding process in the art will select the appropriate laser and welding parameters, according to the battery material, shape, thickness, tensile force requirements, including welding speed, waveform, the peak value, the welding head inclination angle to set a reasonable welding parameters, in order to ensure that the final welding results meet the power requirements of battery manufacturers
Difficulties square battery
Due to factors rectangular battery with the precision of incoming other implications, at the corner of the most prone to problems during welding, it is necessary to constantly explore the actual situation, adjust the welding speed can solve these problems. Round battery no problem in this regard, but the difficulty of subsequent integration into larger battery module.