Welding method, advantages and difficulties of lithium battery in laser welding machine

The technical advantage of laser welding lies in the wide variety of materials that can be welded, and the welding between different materials can be realized. In the welding process of power lithium-ion batteries, welding technicians will select the appropriate laser and welding process parameters, including welding speed, waveform, peak, head tilt, etc., according to the material, shape, thickness and tension requirements of the battery, and set up reasonable welding process parameters to ensure that the final welding effect meets the requirements of power lithium-ion battery manufacturers.

Cylindrical lithium battery

How many welding methods are there for lithium batteries?

① Wave welding:Essentially a combination of ultrasonic welding and laser welding;

② ultrasonic welding: the benefits of this design scheme is a simple welding structure,battery pilot machine but we need companies to take up more space for development, the volume of the module into a group will be less efficient;

dissimilar metal laser welding: this welding method into a group of high efficiency, fast production speed.

Laser welding method

Compared with traditional welding, the advantages of laser welding are as follows.

In many welding methods, lithium-ion battery generated laser welding stands out with the following advantages: first, laser welding high energy density, welding deformation is small, small heat-affected zone, can effectively improve the accuracy of the parts,battery laser welding machine the weld is smooth and dense without impurities, no need for additional grinding work; second, laser welding can be accurately controlled, focusing spot is small, high positioning accuracy, easy to automate with a robotic arm to improve the welding efficiency In addition, laser welding of thin plates or fine-diameter wires will not be as susceptible to reflux disturbances as arc welding.

Lithium battery laser through the welding technology difficulties:

1, aluminum alloy laser welding process is prone to porosity, there are two main types: hydrogen porosity and porosity generated by bubble bursting. Due to the fast cooling speed of laser welding, the hydrogen porosity problem is more serious, due to the collapse of the pores, laser welding appears a new type of holes.

2. Since aluminum alloy is a typical eutectic alloy, it is prone to thermal cracks during welding, including weld crystallization cracks and HAZ liquefaction cracks. Due to eutectic segregation in the weld zone, grain boundary melting will occur,battery packing machine and liquefaction cracks will be formed at the grain boundary under stress, reducing the performance of the welded joint.

Laser welding spatter demonstration

Other difficult points:

1. When welding the soft cladding layer ear plate, the welding equipment requirements are high, and the ear plate must be pressed firmly to ensure the welding gap.

2. The welding of cylindrical batteries is mainly used for the welding of the positive electrode. Because the shell of the negative electrode is very thin, it is easy to weld through.

3. Square power battery for combination can be welded when the pole pole or connecting piece is thickly contaminated, welding technology to connect the record piece, the contaminants through the decomposition, easy to form a welded blow-up point, resulting in these holes; the pole is thinner, under the different plastic or ceramic materials structural parts of the battery, it is easy to weld through. When the pole is small, it is also easy to weld bias to plastic burnout, forming a burst point.

Gantry type lithium battery laser welding equipment

Lithium battery laser welding selection of laser welding equipment, must find experienced laser welding master for sampling confirmation. For the same laser welding equipment, different engineers will have different proofing results.