1. Battery cooling and battery water cooling plate

In battery cooling system applications, liquid cooling has become the mainstream cooling treatment. The heat generated by the car battery in the work is contacted by the electronic device components and the surface of the water-cooled plate, and is eventually taken away by the coolant in the internal flow channel of the cold plate.

The design of the water-cooled plate has a variety, mainly according to the battery type and the overall layout. In order to ensure the temperature uniformity of the high energy battery pack, the longer the cooling channel, the more difficult the temperature uniformity control is.

2.The process changes of the battery water cooling plate

Electric vehicles have developed from ordinary oil in the early days to electricity, and the water-cooled plate process is also changing.

The first generation of products - extruded aluminum profile water cooling plate

The material used for water-cooled plate is generally 6 series aluminum, cold plate forming process is complex, if you want to make a large plate, no large mold, you need to put two or three plates friction stir welding together, so the whole process is more and more complex, plus the welding head is also consumable, so the cost is higher.

The second generation of products - small stamping plate and harmonica tube

The performance of the water-cooled plate directly affects the performance of the battery pack, thus affecting the durability of the electric vehicle. Because the water-cooled plate can easily weigh more than 10 to 20 kilograms, the performance of the battery is greatly limited.

The market has turned its attention to lighter stamping plates and harmonica tubes, and water-cooled plates using brazing technology have entered the public's field of vision. Brazing is widely used and mature in the automobile industry. The front radiator, condenser and plate heat exchanger of automobile all adopt this process. Generally, after coating the welding surface of 3-series aluminum with solder or solder sheet, it is welded in a vacuum brazing furnace at high temperature (about 600℃), and mature brazing technology is the key to the success or failure of the product.

The third generation of products - liquid cooling plate integration and integration

When the energy density of a single unit reaches a certain bottleneck, in order to insert more battery cells into the battery pack, the module becomes larger and larger, and even the concept of the module is cancelled, and the box on the battery pack is directly inserted, that is, the CTP. At the same time, the battery water cooling plate is also in the direction of the large panel, either integrated into the box or module, or made into a large punching plate placed flat on the bottom of the box or covered on the top of the battery.

3.The battery water-cooled plate welding process

Stamping and welding of liquid cooled plates can be relatively complicated. No matter what kind of water-cooled plate processing process we use, welding is a very important process. Nowadays, the welding process of water-cooled plate can be mainly divided into vacuum brazing and friction stir welding, because the structural design of vacuum brazing liquid cooled plate is more flexible, higher welding efficiency and other characteristics, so it is widely used in the field of electric vehicles.

At present, with the diversification of the liquid cooled plate structure, the requirements for welding processes are becoming higher and higher, and the welding process is also developing in the following directions:

1) Improve welding energy efficiency and reduce welding costs;

2) Improve the mechanization and automation level of the workshop, improve the stability of welding quality;

3) The development of new industries continues to promote the development of welding technology;

4) Research and development of heat sources;

5) Energy saving technology is still a common concern.