Electric Vehicle Battery Laser Welding Solutions

November 22, 2022
Posted by Guest Post

The power battery is a new type of clean energy and a globally concerned research topic today. It is the power source for vehicles, mainly including electric cars, electric trains, electric bicycles, and golf carts. The power battery as the main power source is widely used in all aspects of industries and life.

As the core component of new energy vehicles, the power battery directly affects the performance of vehicles. It is composed of positive materials, negative materials (carbon materials), diaphragm, electrolyte, battery shell, and other raw materials.

There are various welding techniques applied to the production of power batteries, ranging from laser welding, resistance welding, ultrasonic welding, cold metal overwelding, brazing to vacuum electron beam welding. Appropriate welding methods and optimized welding parameters have a significant impact on the production cost, performance, and safety when welding power batteries. The laser welding machine is more suitable to be used to weld the above materials into battery cells, PACK modules, etc. The equipment plays a key part in the whole manufacturing process of power batteries.

Each welding techniques have disadvantages despite their advantages in their respective fields. For example, both vacuum electron beam welding and laser welding belong to welding with high energy density and play an important role in welding power batteries and their welding effects are comparable. However, electron beam welding has high demands for the processing environment; that is, this type of welding needs to be executed in the vacuum environment, and it is also difficult to produce on a large scale. In contrast, laser welding is relatively advantageous because it generates fewer consumables and smooth welding joints and features high automation and stability. The laser welding machine is a type of non-contact welding equipment. Its flexibility, accuracy, and high efficiency guarantee the performance of power batteries during production.

Take laser composite welding for example to gain an in-depth knowledge of the role of laser welding machines in the welding of power batteries.

Laser composite welding welds workpieces by focusing two different wavelengths of beams for coaxial synthesis on the welding position. It can reduce heat input by 80% to 90%, increase production efficiency by 3 to 10 times, and reduce production costs by 50% to 80%.

As the core component of new energy vehicles, the power battery is an important source of power for new energy vehicles and its quality directly affects the performance of the whole vehicle. The main parts of power batteries are top covers, which are generally welded by laser composite welding because this welding technique meets relevant manufacturing demands. This welding method generates smooth and flat welding edges with good sealing and without darkening and yellowing phenomenon and cracks. Laser composite welding features other benefits compared with traditional welding:

1. The welding speed can be increased by 2-3 times.
2. The processing power can be reduced by about 30%.
3. The welding quality can be enhanced.

Laser composite welding is characterized by low power supply cost, good arc stability, and improvement in welding joints. This welding method has a smaller melt pool and leads to less workpiece deformation during the welding process, thus greatly reducing workloads for correcting the weld deformation after welding. In addition, The welding speed of laser composite welding is high, which is of help to reduce welding time and cost.

The laser welding machine plays an important part in welding power batteries. The safety, reliability, and service life of power batteries can be enhanced by applying high-efficient and precise laser welding. The general shell thicknesses are required to reach 1.0 mm or less and the mainstream shell thicknesses of power batteries are 0.6mm and 0.8mm according to battery capacities. At present, aluminum-cased batteries account for more than 90% of different types of power batteries. In the welding process, battery-related properties are taken into consideration to select suitable laser welding machines to meet specific demands. These factors include the material, shape, and thickness of batteries to be welded. In addition, welding parameters are also important to welding effects, such as welding speed, waveform, peak value, welding head, and welding angle.