A study on the effect of cell spacing in large-scale air-cooled battery thermal management systems using a novel modeling approach
Amin Moosavi, Anna‐Lena Ljung, T. Staffan Lundström
Abstract
Recent studies have revealed that effective thermal management systems are necessary to maintain the performance, lifespan, and safety of lithium battery systems. A unique and novel modeling approach is presented in this work with the aim of estimating the thermal performance of air-based cooling systems for large-scale lithium battery packages. The overall model consists of sub-models, including an analytical model for battery cells and a numerical heat and flow model for the battery module, which are validated against experimental data and empirical correlations, respectively. The chosen approach implies that the sub-models can operate independently, allowing accurate transient simulations with reduced processing time. The model is employed to evaluate the effect of cell spacing on the thermal performance of an air-cooled battery system designed for a hybrid electric vehicle. The results demonstrate that the maximum temperature within the cells positively correlates with transverse and longitudinal pitch ratios; however, the maximum temperature difference in the module has a negative correlation with these pitch ratios. In contrast, temperature uniformity shows non-monotonic behavior, making it an applicable criterion to balance between temperature rise and thermal gradients. Moreover, considerable temperature non-uniformity is noted in the early rows, which becomes less significant as pitch ratios decrease.