Overview of the liquid cooling principle

Cooling systems based on liquid heat exchange are more efficient than air systems and have a more uniform temperature inside the battery pack of an electric vehicle, but the systems are more complex. The heat transfer from the battery to the liquid phase, for example, can be accomplished by gluing metal to the walls of the container or by embedding it in the container walls.

Similarly, the entire heat transfer can be achieved using heat transfer from the liquid medium, i.e. by arranging pipes between battery modules or by arranging jackets around the modules to achieve heat exchange between the battery and the liquid, such as the designs Trumonytechs has for liquid cooling plates, serpentine bends attached to thermal conductive interface materials (thermal conductive silicone mats, thermal conductive gels, etc.) for heat exchange. At the same flow rate, most direct contact fluids (e.g. mineral oil/water) transfer heat at a much higher rate than air because of their thinner boundary layer and higher thermal conductivity. So in terms of the many ways to dissipate heat from power batteries today, liquid cooling is one of the most promising ways to develop.
Liquid cooling is divided into two ways: direct contact and non-direct contact. Mineral oil can be used as a direct contact heat transfer medium, while water or antifreeze can be used as a typical non-direct contact heat transfer medium. Liquid cooling must pass through a heat transfer facility such as a water jacket in order to cool the battery, which reduces the heat transfer efficiency to a certain extent.