Thermal management structure and method for a square lithium battery pack

Abstract

The invention relates to the technical field of thermal management of lithium ion batteries and a method thereof, in particular to a thermal management structure of a square lithium battery pack. It mainly includes square lithium batteries, semiconductor refrigeration chips, and phase change materials. The two sides of the square lithium battery are in contact with the semiconductor refrigeration sheet. One side of the semiconductor refrigeration sheet is close to the square lithium battery and the other side is close to the phase change material. The two sides of the phase change material are in contact with the semiconductor refrigeration sheet. The heat management structure of the battery pack provided by the present invention is charged and discharged at a high rate, the heat generated by the battery is transmitted to the phase change material through the semiconductor cooling sheet, and the phase change material is used for cooling. If there is still a need for further cooling, the semiconductor cooling sheet is energized to work. The cooling on the battery side can further reduce the maximum temperature of the battery, and can realize the heat dissipation function of the battery pack even when the ambient temperature is high. When the temperature is below zero, a reverse current is passed through the semiconductor refrigeration sheet to heat the battery side, which is highly efficient and low energy consumption, and realizes the heating function of the battery pack.

Description

technical field [0001] The invention relates to the technical field of thermal management of lithium batteries, in particular to a thermal management structure and method for a square lithium battery pack. Background technique [0002] Lithium batteries have been widely used in various fields due to their excellent charge and discharge performance. Among them, the square lithium battery is one of the most commonly used battery types for power batteries in the automotive field. Temperature has a great impact on battery performance and safety, so thermal management is particularly important. Especially for square lithium batteries, as the volume of the cells increases, the distance between the heat-generating parts inside the battery and the case becomes longer and longer, and there are more and more conductive media and interfaces, making heat dissipation difficult. At present, the main methods of battery thermal management include air cooling, liquid cooling, phase change ...

AI Technical Summary

Problems solved by technology

Air cooling is difficult to meet the heat dissipation requirements when the battery pack generates a lot of heat, and the air cooling effect is easily affected when the ambient temperature is high such as summer

The main problems of liquid cooling are complex structure and high energy consumption.

However, the main problem is that it is difficult to select the phase transition temperature. Generally, the phase transition temperature of the phase transition materials used in most studies on the cooling of battery phase transition materials is relatively low (25°C-40°C). The main reason is that if the phase transition The phase change temperature of the material selection is higher, that is, it is difficult to melt, and the cooling effect on the battery is not good, and the thermal conductivity of the phase change material is usually low, so if you do not use its latent heat, you will not be able to take advantage of it, but will affect heat dissipation

The main reason for the lack of research on cooling batteries with semiconductor refrigeration chips is that in order to achieve a better cooling effect, it is necessary to ensure better heat dissipation on the heating side. Usually, liquid cooling is used to take away the heat. The structure is complex and the energy consumption is high. Therefore, the overall performance bad

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