Solutions for Electric Vehicle Battery Cooling Plates

With the shortage of traditional energy and the increasingly prominent environmental problems, the development

of new energy vehicles, which can replace traditional vehicles, has increasingly become a focus of attention. As the

core component of new energy vehicles, the importance of safety issues is evident. The internal temperature of the

battery pack directly affects its safety, which in turn affects the safety of the vehicle. To improve the safety of the 

battery pack, it is necessary to control the temperature of the internal structure. Therefore, it is very important to

increase the heat dissipation performance of the overall structure. The use of liquid cold plate has important application

significance to ensure the safety of the battery pack and improve the service life.

As the main energy storage element in electric vehicles, battery modules are key components of electric vehicles and 

directly affect the performance of electric vehicles. During the use of the battery module, since the internal cells have

a certain internal resistance, a certain amount of heat will be generated during normal operation, which will increase

the internal temperature of the module. The normal working temperature range of the battery cell is 15-35 ℃. If it

exceeds 60 ℃, it will cause certain safety hazards. The generation and rapid accumulation of heat will inevitably 

increase the internal temperature of the battery, especially when used in a high temperature environment or when

charging and discharging with a large current. , it may cause a violent chemical reaction inside the battery and 

generate a lot of heat. If the heat accumulates rapidly inside the battery before it can be dissipated in time, the 

battery may leak, outgas, smoke, etc. In severe cases, the battery will burn violently or even explode. In order to

eliminate this danger, it is necessary to dissipate heat from the battery module, so as to prevent the battery cells

from being in a high temperature state for a long time, thereby affecting the performance of the battery cells 

and reducing the service life of the battery cells

Heat pipe technology can meet the requirements of high temperature heat dissipation and low temperature preheating 

of the battery pack. It is sensitive to temperature changes and has good temperature uniformity. As a cooling system

for battery packs, there has been a certain development. In the new energy power battery system, there are various 

heat dissipation methods, and the current common application methods are air cooling and liquid cooling. Winshare

Thermal can provide a variety of liquid cold plate production processes, including friction stir welding, profile 

water-cooled plate processing, brazing technology, and copper tube + aluminum plate technology;

From the perspective of existing electric vehicle power battery cooling methods, air cooling has always occupied a major 

position, especially Japanese electric vehicles, which basically use air cooling technology. With the increasing requirements

for batteries in the application environment, liquid cooling has also become a priority solution for car companies. Mainstream

electric passenger car companies have also begun to turn to liquid cooling systems. From the perspective of medium and

long-term trends, liquid cooling will occupy the mainstream. The current application form is that a liquid-cooling plate is 

usually installed in the battery module, and liquid is injected into the liquid-cooling plate to dissipate heat for the cell. The 

actual working temperature of the liquid-cooling plate is 10-20 °C, and the circulating liquid The refrigerant takes away 

heat and cools the battery to achieve the purpose of heat dissipation.

Among them, Winshare Thermal's battery liquid cold plate generally uses aluminum substrates to bury copper tubes in the

design process, that is, aluminum substrates are machined with computer numerical control technology to mill grooves, and

then a punching machine is used to press the bent copper tubes to the aluminum substrate. above, and then braze welding.

This design, on the one hand, the lightweight of aluminum plays a role in weight reduction and cost control, and on the other

hand, the high thermal conductivity of the copper tube has also been fully utilized. Finally, two inlets and outlets are set to 

inject the corresponding liquid refrigerant, generally water or a mixture of water and organic alcohol (alcohol can prevent 

water from freezing at low temperature), and the water pump controls the circulation of the liquid. Water or its mixture with

organic alcohol is used as a liquid cooling radiator, because in physics, the thermal conductivity and specific heat capacity of 

water are much larger than those of air, the heat conduction speed is fast, and the temperature rise is relatively slow, so water 

is a comparison. ideal cooling medium. In the battery pack, because depending on the environment, the water is easy to freeze

in the low temperature environment, which is very unfavorable for heat dissipation. In order to solve this problem, the mixing

ratio of water and organic alcohol is generally used as the refrigerant, and the results are very good. 's verification.

The working principle of the liquid cooling plate is: the excess heat generated by the battery operation is transferred through 

contact with the surface of the plate-shaped aluminum device. It is carried away by the coolant passing through the internal 

flow channels of the device. Similarly, when the battery cannot work under low temperature conditions, at this time, after the

liquid in the water-cooling plate is added, the temperature of the entire system rises to ensure that the battery works under

a suitable temperature condition.