Why is ethylene glycol used as a coolant in electric vehicles?

Why is ethylene glycol used as a coolant in electric vehicles?

With the popularity of electric vehicles (EV), the thermal management of batteries and electric motors is becoming more and more important. High-performance batteries and motors of electric vehicles generate a lot of heat during operation. If they are not released in time, they may cause performance degradation, shortened life, and even cause safety problems. Therefore, choosing the right coolant is essential for the efficient operation of electric vehicles. Among them, ethylene glycol, as a common coolant, is widely used in the cooling system of electric vehicles because of its excellent performance. Why is ethylene glycol selected as a coolant for electric vehicles? This article will analyze in detail from multiple perspectives.

1. Electric vehicle thermal management needs

The core components of electric vehicles include battery packs and electric motors, which generate a lot of heat during operation. During the charging and discharging process of the battery pack, temperature changes will affect the efficiency and life of the battery; and the motor will also generate high temperature when running under high load, which may cause damage to the insulating layer. Therefore, electric vehicles need an efficient cooling system to maintain the temperature of these components within a reasonable range.

Compared with traditional fuel vehicles, the cooling system of electric vehicles needs to deal with higher thermal load and more complex heat distribution. A battery pack is usually composed of multiple battery cells, and the temperature of each battery cell needs to be precisely controlled to avoid overheating or overcooling. The cooling system of electric vehicles also needs to have good corrosion resistance and long service life to adapt to the complex operating environment.

2. Ethylene glycol excellent performance

Ethylene glycol (Ethylene Glycol) is a colorless, odorless, non-toxic liquid commonly used in the manufacture of antifreeze and coolants. Its chemical properties make it ideal for electric vehicle cooling systems. The following are the main advantages of ethylene glycol as a coolant:

(1) Good heat transfer performance

Ethylene glycol has a high specific heat capacity and thermal conductivity, which means that it can quickly absorb and transfer heat. In the cooling system of electric vehicles, ethylene glycol can effectively transfer the heat generated by the battery pack and electric motor to the radiator or other heat dissipation device, thereby keeping the temperature of the system stable.

(2) Anti-freezing and anti-boiling performance

A remarkable feature of ethylene glycol is that it can be mixed with water to form an antifreeze. In the cold winter, ethylene glycol can significantly reduce the freezing point of the coolant and prevent the cooling system from freezing in a low temperature environment. Ethylene glycol can also increase the boiling point of the coolant, thereby preventing the coolant from boiling in a high temperature environment and ensuring the normal operation of the cooling system.

(3) Corrosion resistance

Ethylene glycol has excellent corrosion resistance and can effectively prevent corrosion of metal parts (such as aluminum, steel, copper, etc.) in the cooling system. This is essential for the long-term operation of electric vehicles, because corrosion problems can cause leakage or damage to the cooling system, which in turn affects the performance and safety of the vehicle.

(4) Environmental protection and biodegradability

Although ethylene glycol itself is not a completely environmentally friendly substance, it is more biodegradable than other coolants (such as silicone oil). This means that if the glycol coolant leaks into the environment, its harm to the ecosystem is relatively small. The production process of ethylene glycol is also continuously improved to reduce the impact on the environment.

3. Ethylene glycol in electric vehicles in the specific application

In electric vehicles, ethylene glycol is usually mixed with water in a certain proportion to form an efficient coolant. This cooling liquid is used in the cooling system of the battery pack to prevent the battery from overheating or overcooling. Glycol is also used in the cooling system of electric motors to ensure that the temperature of the motor is stable during high-load operation.

For example, high-end electric vehicles such as the Tesla Model S use glycol as a coolant to ensure efficient operation of the battery pack and motor. By using a glycol cooling system, these vehicles can achieve higher cruising range and longer battery life.

4. Future development trend

Although ethylene glycol performs well in electric vehicle cooling systems, as technology advances, researchers are exploring more efficient and environmentally friendly coolants. For example, some new synthetic coolants and natural coolants (such as carbon dioxide-based coolants) are being developed to further improve cooling efficiency and reduce environmental impact.

The cooling system of electric vehicles is also developing towards integration and intelligence. The cooling system of the future may use artificial intelligence technology to monitor the temperature of the battery pack and motor in real time, and adjust the flow and temperature of the coolant according to the actual situation to achieve more efficient thermal management.

5. Summary

Ethylene glycol is used as a coolant for electric vehicles mainly because of its excellent heat transfer performance, anti-freezing and anti-boiling performance, corrosion resistance and environmental protection. These characteristics make it ideal for electric vehicle cooling systems. With the advancement of technology, more efficient and environmentally friendly coolants may appear in the future to further improve the performance and safety of electric vehicles.

The application of ethylene glycol in the cooling system of electric vehicles not only solves the thermal management problem of electric vehicles, but also provides important technical support for the popularization and promotion of electric vehicles.