A composite electrochemical-thermal model for the determination of thermal profiles of lithium-ion cell for electric vehicle application

The present work is to describe the electrochemical-thermal profiles of a Li-ion cell of a battery pack for an electric vehicle application considering a realistic drive-cycle. For this investigation, a tropical country like India is considered. The atmospheric temperature varies at different locations of India, and hence, a range of temperatures (25–55°C) is taken into consideration for the study. An electrochemical-thermal model featuring physics laws has been considered as it can provide all the electrochemical kinetics and side reactions to get more accurate results. The two-way coupled electrochemical-thermal model consisting of a 1-dimensional electrochemical model for heat generation and a 2D thermal model to show temperature distribution over the cell is developed. Thermal contact resistance is modeled which is formed in between the battery electrode coatings and current collectors due to imperfect contact at the time of electrode fabrication. This model is first tested with standard charge–discharge profiles at different C-rates, and thereafter, it is validated with the experimental results. Finally, the model is tested with a standard drive-cycle called modified Indian driving cycle, and the results are analyzed. Comments are made on the state of charge (SoC) of Li-ion cell as well as SoC of electrodes. The temperature profiles of the cell show a range of ambient temperatures, and results are reported.