Power lithium batteries are widely used in new energy vehicles because of their high energy density, high voltage, high specific power, good cycle performance, and no pollution. In order to meet the energy and range required for normal driving, the number of batteries is large, and the single cells are generally arranged in series and parallel to form a battery pack to save installation space.

The individual temperature difference is caused by the different heat dissipation environments in the battery pack. Under the effect of thermoelectric coupling, the internal resistance of the battery with high temperature will be reduced, which makes the current flowing through the battery increase, and the state of the single battery charge point becomes more and more uneven, which accelerates the deterioration of the battery pack, and then affects the efficiency and life of the battery, and even has serious safety hazards. Therefore, it is necessary to carry out effective thermal management for the heat dissipation performance of the battery pack and the inconsistency between the cells.

Research shows that the best operating temperature range of lithium batteries is 15-35 ℃, control the temperature difference between the single-cell does not exceed 5 ℃, the maximum safe temperature does not exceed 55 ℃, the battery pack can obtain better performance and life.

Of course, this is from a research perspective, without taking into account the intensity of industry competition and the real demand of the market. Therefore, many enterprises pursue the extreme temperature environment when the battery works. It is precisely because they have higher requirements for this safety and stability data that the battery products produced by enterprises can surpass their competitors in quality, attract more long-term and stable customers, occupy more market share and promote the further development of the enterprise. GDBELL has a deep understanding of the research on battery environmental reliability test equipment. It is in a leading position in the industry for temperature control. For various special requirements of customers, we can give an appropriate solution to help enterprises better carry out battery safety and stability tests, and optimize and upgrade the product manufacturing process through data analysis, Produce better quality batteries.

Returning to the theme of this article, the research on heat dissipation of cylindrical lithium battery, we will mention the common heat management technologies, including air cooling, liquid cooling and phase change cooling. Compared with other cooling methods, air cooling technology has lower cost and simple system structure. It has become one of the most commonly used solutions for thermal management of power lithium battery.

The cooling system heat dissipation performance is mainly affected by the media properties and heat dissipation structure. The media properties affect the heat transfer efficiency of the cell surface, and the heat dissipation structure affects the internal flow field of the battery pack, which in turn affects the overall heat dissipation efficiency. Through experiments and numerical simulations, the thermal performance of fog cooling is investigated, and it is found that the cell temperature distribution is more uniform and lower using a fog cooling system than using a dry air cooling system, and the performance is improved up to 45%.

CFD simulations are performed on the parallel air cooling system to study the effects of cell operating parameters and structural parameters on the cooling performance. The results show that either reducing the inlet air temperature or increasing the inlet flow rate can reduce the maximum cell temperature. Changing the angle of inlet and outlet air chambers can effectively improve the cooling performance of the system.

The optimal pressure chamber width and cell spacing parameters were solved separately using a combination of introducing Newton’s method and flow resistance network simulation. The system with structural optimization based on the solution values has significantly improved the cooling performance and reduced the maximum temperature difference of the battery pack by more than 40%.

An air-cooled system with couples thermo-electric technology was also designed, and numerical calculations showed that the battery temperature could be kept below 35°C with a temperature difference of no more than 5°C at high charge and discharge rates and ambient temperatures greater than 40°C.

Conclusion

• The modeling and numerical simulation analysis of the air-cooled heat dissipation structure of cylindrical lithium battery fork arrangement. The closer the cells are in the shell, the better the cell heat dissipation effect. For single-row parallel cells, the air temperature gradually increases and the single-cell heat dissipation effect becomes worse.

• When the shape, size of the battery pack, and the fan power are certain, the heat dissipation performance is affected by the air duct width and air inlet area. When the width of the air duct increases, the air inlet area increases, the effective air volume of the air duct increases, and the cooling performance of the battery is improved.

The above is the introduction of air cooling and heat dissipation of lithium battery pack. If you want to know more details, please contact us through the official website or email. GDBELL has been engaged in the manufacturing industry of battery testing equipment for more than 15 years. Relying on a strong R & D team of engineers and profound manufacturing experience, GDBELL has solved the personalized requirements of countless enterprises for lithium battery testing. The company’s training for employees in dealing with business is based on Building Advisory sales service, which makes the subsequent trade communication go very smoothly, the order turnover is very considerable, and the strong after-sales team provides a solid guarantee for customers. Therefore, customers have a steady demand for our products. Most of them have established cooperative relations with the first order and continuously give more orders, which makes GDBELL’s position in the industry continue to improve. More and more enterprises choose to use our lithium battery test equipment. After years of testing in the international market, the data tested by our test equipment has helped most customers and has been highly praised. Therefore, you can rest assured to ask and buy our equipment. Our business team will give you a satisfactory answer within 12 hours as soon as possible.