With the continuous improvement of our technology, nowCar battery nickel plateIt has been getting better and better, and automotive battery nickel strips are used in many industry fields. Generally speaking, nowadays various alloy materials, especially aluminum alloy battery cases, account for as much as 90% of power batteries. It can be said that most power batteries use aluminum alloy, but aluminum alloy has a relatively high reflectivity to lasers, which means there are certain difficulties in welding. Next, we will introduce some common issues encountered during welding.

1. Stomata

Porosity is easily generated during the laser welding of aluminum alloys, mainly in two types: hydrogen pores and pores caused by bubble collapse. Due to the extremely fast cooling rate in laser welding, the problem of hydrogen pores is more severe, and in laser welding, there is also an additional type of hole caused by the collapse of small pores.

2. Hot cracks

Aluminum alloys belong to typical eutectic alloys and are prone to hot cracking during welding, including weld solidification cracks and HAZ liquation cracks. Due to composition segregation in the weld zone, eutectic segregation can occur, leading to grain boundary melting. Under the action of stress, liquation cracks can form at the grain boundaries, reducing the performance of the welded joints.

3. Fire explosion

Spatter (also called splash) issues. There are many factors that cause spatter, such as the cleanliness of the material, the purity of the material itself, and the characteristics of the material, but the decisive factor is the stability of the laser. Surface protrusions, pores, and internal bubbles in the casing. The reason is mainly due to the fiber core diameter being too small or the laser energy being set too high. It is not, as some laser equipment providers advertise, that 'the better the beam quality, the better the welding effect.' Good beam quality is suitable for overlay welding with larger penetration depth. Finding the right process parameters is the key to solving the problem.

The above three points are some of the common difficulties encountered when welding nickel strips for car batteries. In practical applications, different parts have different welding challenges, and appropriate solutions should be chosen according to their characteristics. Yixing Xindake New Energy Technology Co., Ltd. is a company dedicated to the research, design, production, and sales of lithium battery pack accessories. It has a professional technical team and extensive experience, and is highly praised in the industry. Therefore, if anyone has needs in this area, you can contact us for consultation.