Large and High Power Cylindrical Batteries – Analysis of the Battery Packs Temperature Distributions Using COMSOL Multiphysics

A good cooling inside a battery pack is important to avoid safety issues and avoid the development of too large internal temperature gradients. The temperature distributions inside two packs (in-line and staggered) made of large cylindrical lithium iron phosphate cells (of 18 Ah nominal capacity) are analysed in this paper during a 90 A constant discharge current. The analysis of the battery packs temperature distributions is based on the results obtained with a two-dimensional modelling approach. For both packs, the simulations results indicate that a better cooling of the cells located at the rear of the packs occurs with the increase of the air inlet velocity. In these packs, the regions inside the cells show the highest temperature values and a faster temperature increase in time compared to the cells surface regions.