The lithium-ion battery (LIB) is one of the preferred candidates for electric vehicle (EV) and hybrid electric vehicle (HEV) applications due to its outstanding characteristics such as high energy density, modular scalability, long cycle life, and low self-discharge rate among others. In a battery module for EV applications, an uneven temperature distribution in the module can be created depending on the operating conditions and the types of thermal management. Uneven temperature distribution in a module could cause an electrical imbalance and thus lead to the lower performance and shorter life of battery. Therefore, it is important to calculate accurately the uneven temperature distribution in a battery module in order to achieve the optimum performance and long life of the battery module.
In this work, a three-dimensional modeling is performed to investigate the effects of the design of air cooling channels on the thermal behavior of an LIB module. Thermal conductivities of various compartments of the battery are estimated based on the equivalent network of parallel/series thermal resistances of battery components. Heat generation rate in an LIB cell is calculated by using the modeling results of the potential and current density distributions of a battery cell.
Fig. 1 shows the schematic diagram of the battery module composed of 24 cells with two types of air cooling channels. The average temperatures from the experimental measurement for the LIB module for US06 cycle profile are compared with those predicted by the modeling in Fig.2.