The influence of different welding methods on the battery

Side welding and top welding are the two main welding methods for power battery shells. Each has its own processing advantages and disadvantages. At the same time, most power batteries use aluminum shell materials due to its material characteristics, which are prone to bulges and pores during processing.
Especially square batteries are most prone to problems when welding at the corners.

Here are some difficulties in power battery packaging and welding:

1. The technological difficulties of power battery welding
Generally, the thickness of the aluminum shell of power battery is required to be below 1.0mm, and mainstream manufacturers currently use two kinds of shell material thicknesses of 0.6mm and 0.8mm according to the battery capacity. Welding methods are mainly divided into side welding and top welding. The main Side welding and top welding are the two main welding methods for power battery shells. Each has its own processing advantages and disadvantages. At the same time, most power batteries use aluminum shell materials due to its material characteristics, which are prone to bulges and pores during processing.
Especially square batteries are most prone to problems when welding at the corners.

Here are some difficulties in power battery packaging and welding:

1. The technological difficulties of power battery welding
Generally, the thickness of the aluminum shell of power battery is required to be below 1.0mm, and mainstream manufacturers currently use two kinds of shell material thicknesses of 0.6mm and 0.8mm according to the battery capacity. Welding methods are mainly divided into side welding and top welding. The main advantage of side welding is that it has less impact on the inside of the cell and spatters will not easily enter the inside of the cover.
Since the welding may cause bumps, which will have a slight impact on the subsequent assembly process, the side welding process has higher requirements on the stability of the laser, the cleanliness of the material, and the matching gap between the top cover and the aluminum case of the power battery . As the top welding process is welded on one surface, a more efficient galvanometer scanning welding method can be used, but the requirements for the previous process to enter the shell and positioning are very high, and the equipment automation requirements are high.
2. Difficulties in welding power battery aluminum shell
At present, the power battery aluminum shell accounts for more than 90% of the entire power battery. The laser welding of aluminum is very difficult, and it will face the problem of raised surface of the weld mark, pores, fire, internal air bubbles, etc. Surface protrusions, pores, and internal bubbles are taboos for laser welding.

Many battery manufacturers will be troubled by this in the early stage of development. The main reason is that the fiber core diameter is too small or the laser energy is set too high. , Such as the cleanliness of the material, the purity of the material itself, the characteristics of the material itself, etc., and the stability of the laser plays a decisive role.
In power battery welding, the welding process technicians will select the appropriate laser and welding process parameters according to the customer’s battery material, shape, thickness, and tensile requirements, including welding speed, waveform, peak value, welding head tilt angle, etc. to set reasonable Welding process parameters to ensure that the final welding effect meets the requirements of power battery manufacturers.
3. Difficulties in welding square power battery
Due to factors such as the matching accuracy of the incoming materials, the square battery is most likely to have problems at the corners during welding. It is necessary to continuously explore according to the actual situation and adjust the welding speed to solve these problems. The circular battery does not have this problem, but the subsequent integration into a battery module is more difficult.
The difficulties of power battery welding are shared here for you. As long as we understand these difficulties in power battery welding, we believe we will be able to break through the welding difficulties.

to sum up:
1. The reasons for the fraud caused by aluminum shell batteries: the cleanliness of the material, the purity of the material itself, the characteristics of the material itself, etc. The most decisive key component is the stable performance of the laser.
Second, the corner and corner welding of the square battery needs to slow down the welding speed
3. Side welding has the least impact on the cell, and spatter will not fall into the shell.
Fourth, the top welding needs to cooperate with the galvanometer system, which requires high automation.
5. Surface protrusions, pores, and internal bubbles are fatal injuries to laser welding. Therefore, technicians need to select the appropriate laser and welding process parameters according to the battery material, thickness, and shape tensile requirements.