Influence of ambient temperature, discharge C‐rate, and convective heat transfer coefficient on thermal behaviour of lithium‐ion battery pack: A numerical study

Abstract Lithium‐ion batteries play a crucial role in reducing carbon emissions and promoting the use of electric vehicles. There are numerous input variables influencing the thermal profile of lithium‐ion batteries. Therefore, a precise assessment of the relative contributions of various factors is essential for optimizing thermal management and control processes. In this study, we tested a lithium‐ion battery pack composed of five 14.6 Ah prismatic cells connected in series under different discharge rates (2C, 3C, 4C, and 5C), ambient temperatures (30, 35, 40, and 45°C), and convective heat transfer coefficients (5, 10, 20, and 40 ). Results showed that the ambient temperature with a contribution of 58.01% had a strong influence on the maximum battery pack temperature. Furthermore, the influences of discharge C‐rate and convective heat transfer coefficient on the maximum battery pack temperature were identical. Moreover, it was found that the homogeneousness of the battery pack was very sensitive to the discharge C‐rate, contributing 71.07% to the increase in temperature difference. To ensure battery pack temperature and temperature uniformity at the same time, moderate ambient temperatures, low discharge C‐rates, and high convective heat transfer coefficients can be preferred. Consequently, the statistically obtained results in this study may contribute towards performance optimization and improved thermal safety of lithium‐ion battery packs.