For some high power devices, such as SVGs, inverters, IGBTs, etc., water cooling plate heatsinks can be used for cooling, and the cooling effect is very good. One important factor driving the continuous iteration and development of water cooling plates is to improve thermal conductivity. There are usually several solutions provided by our battery tray manufacturers to improve thermal conductivity: increase the contact area between the cold plate and the battery core; increase the thermal conductivity of the interface between the cold plate and the battery core; improve the thermal conductivity performance of the cold plate (material); adjust the channel design to improve the heat exchange effect of the fluid; and different cold plate placement schemes.
Currently, the main material used for water cooling plate China is aluminum alloy. Although copper has better thermal conductivity, it is much more expensive, so it is not the mainstream direction and is applied in the non-battery field. For improving the thermal conductivity of the thermal interface, the main task is to work on the thermal interface material TIM. The thermal conductivity effect of TIM has been continuously improved from the previous air medium to the later thermal conductive pad, and now to the thermal conductive adhesive.
After confirming the above two points, the focus of the design of the liquid cooling plate China is basically on improving the contact area between the cold plate and the battery core, adjusting the channel design, and improving the effect of the fluid itself. We can compare this change with Leonardo's classification of the cooling effect (comprehensive heat exchange coefficient) required for different charging powers.
The stamping channel and convex design of the large flat cold plate design cater to the current fast charging and large module, CTP design concept, and are the main application trend currently. In addition, depending on whether there is a module, interface material TIM, box, and battery core, and the location of the cold plate, there are at least six schemes for the layout of the cold plate. Among them, the integration of the water cooling plate in the box is currently a popular design concept. The design concept of inner fins is widely used in power electronics and electricity, but there are no mass production cases in the battery system field yet, but some Chinese enterprises are doing this. In terms of materials, in addition to metal, some material companies are trying the solution of plastic cold plates. This is a very exciting direction, and we look forward to mass production solutions.
Super-fast charging puts higher demands on battery cooling. Good cooling solutions are often the result of a systematic work matching these 5 points, which tests the comprehensive design capabilities of each company. Nowadays, relying on the flow of liquid transfer high heat is one of the most effective ways of cooling, and water cooling plates have become a mainstream cooling solution.