Study on the Performance of Parallel Air-Cooled Structure and Optimized Design for Lithium-Ion Battery Module

Temperature and temperature consistency have an important effect on the effective performance and thermal safety of lithium-ion batteries. Huge temperature inconsistency can lead to the behavior of overcharge and overdischarge so that it improves the risk of fire and thermal runaway. Temperature rise and heat generation rate during discharging under adiabatic condition are measured by experiments. Based on the conclusion and data obtained by experiments, the finite element model of traditional and optimized parallel air-cooled structure are built by COMSOL Multiphysics 5.3a(R). Meanwhile, the problem of flow inhomogeneity in parallel air-cooled structure and the cooling performance of optimized design are researched and discussed. Obvious temperature inconsistency is observed inside the battery module with a traditional cooling structure. Adding a fan on the bottom of module contributes to decay the maximum temperature and improve the temperature consistency effectively. The average temperature difference is maintained at about 1.4 degrees C when the velocity of inlet air exceeds 7 m s(-1), which is merely half of that in traditional structure. Temperature difference inside battery module is smaller with the rise of inlet air velocity. Moreover, temperature consistency could be improved by increasing the radius of fan or setting the outlet on the right above of battery module.