Design optimization of forced air-cooled lithium-ion battery module based on multi-vents

In this paper, a multi-vent-based battery module for 18,650 lithium-ion batteries was designed, and the structure of the module was optimized by computational fluid dynamics (CFD) method. Compared with the previous researches on the layout of one air inlet and one air outlet, the thermal management system with multi-vents was more effective for improving the cooling performance. Firstly, the effects of the number, size and position of vents on the cooling performance of the battery module were explored. Then, the uniform variation of the spacings among the battery cells and the uneven variation of the spacings among internal, middle and external cells were discussed. Finally, the thermal states of the battery module under different air inlet velocity and discharge rate were analyzed. The results indicated that the layout with one inlet located at the top center and four outlets located at the lower right corner of four sides was superior to other layouts. The maximum temperature and the maximum temperature difference of which were reduced by 7.167 degrees C (16.4%) and 3.216 degrees C (48.7%) compared with the original model. When the cell spacings were varied uniformly, the cooling effect of 1 mm spacings was more significant; the cell arrangement mode with dense inside and sparse outside obtains the best cooling effect when the cell spacings were varied unevenly under fixed battery module volume. After optimization, the maximum temperature and the maximum temperature difference were reduced by 7.260 degrees C (16.6%) and 5.016 degrees C (76.0%) respectively. Furthermore, when the batteries were discharged at 3C rate, at least an air inlet velocity of 2 m/s could be provided to enable the optimal module to operate stably. The present study provided an effective thermal management strategy for forced air-cooling systems.

Automated summary

In this study, a multi-vent-based battery module for 18,650 lithium-ion batteries was optimized using computational fluid dynamics, demonstrating improved cooling performance compared to previous single-vent designs. The effects of vent number, size, and position, as well as battery cell spacing variations, were explored to achieve a superior thermal management strategy for forced air-cooling systems.