Effect of Operating Parameters on Thermal Behaviors of Lithium-Ion Battery Pack 2016-01-1211

Power lithium-ion battery is the core component of electric vehicles and hybrid electric vehicles (EVs and HEVs). Thermal management at different operating conditions affects the life, security and stability of lithium-ion battery pack. In this paper, a one-dimensional, multiscale, electrochemical-thermal coupled model was applied and perfected for a flat-plate-battery pack. The model is capable of predicting thermal and electrochemical behaviors of battery. To provide more guidance for the selection of thermal management, temperature evolutions and distributions in the battery pack at various ambient temperatures, discharge rates and thermal radiation coefficients were simulated based on six types of thermal management (adiabatic, natural convection, air cooling, liquid cooling, phase change material cooling, isothermal). It can be concluded that thermal radiation has little effect on temperature rise, but it cannot be ignored with increasing depth of discharge (DOD) and discharge rate. How to make the battery operate in optimum working temperature (OWT) region under various working conditions was analyzed in details. Furthermore, the differences of temperature distributions in spatial and temporal scales under various operating conditions were discussed and presented, and some constructive suggestions also were proposed for further studies. Temporal temperature distribution changes more intensely especially in the center of the battery pack, and it is more susceptible to the ambient temperature. These changes are repeated in different locations under the situation that lower discharge rates but better cooling effects. However, changes of spatial temperature distribution are monotonic, and its magnitude mainly depends on the cooling effects.