The method of cooling the power cell of the core part of the new energy electric vehicle

The power battery is the core of electric vehicles, to be able to withstand high temperatures and waterproof and frozen. Electric vehicles appear to be unable to drive, and the time before the "core"(battery) problem will be thought of. In the hot summer atmosphere, can the power battery withstand the heat of 40 degrees?

How to heat up electric car power battery? The power cell has a large current and a large heat production. At the same time, the battery pack is in a relatively closed environment, which leads to an increase in the temperature of the battery. This is because of the electrolyte in the lithium battery. The electrolyte acts as a charge conduction inside the lithium battery. A battery without an electrolyte is a battery that can not be charged and discharged.

Liquid thermal-conducting Silicon film for water-cooled tubes

Most lithium batteries are flammable, volatile non-aqueous solutions. This component system has higher energy and voltage output than batteries composed of aqueous electrolytes, which meets the user's higher energy requirements. Because the non-aqueous electrolyte itself is flammable and volatile, it infiltrates the inside of the battery and also forms the combustion source of the battery.

Therefore, the operating temperature of the above two battery materials must not be higher than 60 °C, but the outdoor temperature is now close to 40 °C. At the same time, the battery itself produces a large amount of heat, which will lead to an increase in the working environment temperature of the battery, and if the heat is out of control, The situation will be very dangerous. In order to avoid becoming a "barbecue," it is particularly important to heat the battery.

Thermal conductive material for power cells

There are two kinds of active and passive heat dissipation in the battery pack of the power battery, and there is a great difference in efficiency between the two. Passive systems require lower costs and simpler measures. The active system structure is relatively complex and requires more additional power, but its thermal management is more effective. Different heat transfer media have different heat dissipation effects, air cooling and liquid cooling have their own advantages and disadvantages.

The main advantages of using gas(air) as a heat transfer medium include: simple structure, light quality, effective ventilation when harmful gas is produced, and low cost; The disadvantages are: low heat transfer coefficient, slow cooling speed and low efficiency between the wall surface of the battery. There are many applications at present. The main advantages of using liquids as heat transfer media are:

Power cell thermal conductive Silicon film

The heat transfer coefficient is high and the cooling speed is fast. The disadvantages are: high sealing requirements, relatively large quality, complex repair and maintenance, need water cover, heat exchanger and other components, the structure is relatively complex. In the actual application of electric buses, due to the large capacity and large size of the battery pack, the power density is relatively low, so air-cooled schemes are mostly used. For ordinary passenger car batteries, the power density is much higher. Correspondingly, its requirements for heat dissipation will also be higher, so water-cooling schemes are also more common.

Different battery pack structure sensors will be determined according to temperature measurement points and requirements. Temperature sensors will be placed in more representative, temperature variations, such as air inlet and outlet locations and the middle area of the battery pack. In particular, at higher and lower temperatures, and in areas where the heat accumulates more strongly in the center of the battery pack. This helps to control the temperature of the battery in a relatively safe environment and avoids the danger of overheating and overcooling the battery.

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