Thermal modelling and characteristic evaluation of electric vehicle battery system

Thermal modelling of Li-ion battery system used in electric/hybrid electric vehicles is carried out. The main highlight of this study is the numerical modelling of Li-ion battery using finite volume method with the adoption of realistic coupled heat and fluid flow process. Thermal characters of the battery system are analyzed with the change in parameters like flow Reynolds number, battery internal heat generation, the length to width ratio, and the conduction-convection related parameter at the interface of battery and air. In detail analysis of maximum temperature, heat flux variations, Nusselt number, friction coefficient, coolant temperature, and velocity distributions are carried out. Finally, the effect of channel width formed between two parallel placed battery cells is also carried. The numerical analysis performed reveals that the length to width ratio of battery does not impact the thermal performance of battery. At lower Reynolds number, the conduction-convection parameter plays a significant role in reduction of battery temperature avoiding thermal stresses developed. Channel spacing has a prominent role in variation of battery and coolant temperature. The battery surface temperature is largely affected by parameters considered. However, it is at higher input of conduction-convection parameter, Reynolds number, and channel spacing the thermal variation remains insignificant.

Automated summary

The thermal modeling of Li-ion battery system used in electric/hybrid electric vehicles was conducted in this study, focusing on parameters such as flow Reynolds number, battery internal heat generation, and conduction-convection related parameters. The analysis revealed that the length to width ratio of battery does not impact thermal performance, and at lower Reynolds numbers, the conduction-convection parameter plays a significant role in reducing battery temperature. Additionally, channel spacing has a prominent role in variation of battery and coolant temperature.