A new multiphysics modeling framework to simulate coupled electrochemical-thermal-electrical phenomena in Li-ion battery packs

This study introduces a streamlined modeling framework that integrates a volume-averaged thermal (VAT) model with the Tank-in-Series battery model, a recently developed volume-averaged electrochemical model. The framework enables efficient simulations of electrochemical-thermal interactions in large-scale battery packs. This framework is used to investigate the effects of coolant flow rates and inlet temperature, initial and ambient temperatures, battery pack configurations, and cell-to-cell manufacturing related variations. Results showed a notable current distribution variation among modules connected in parallel at the end of discharge and beginning of charge. This is found to be directly related to the temperature variation in the battery pack governed by the coolant mass flow rate. Additionally, with the introduction of a 0.5% cell-to-cell to variation in the cell design parameters for the purpose of simulating manufacturing variation, a significant voltage variation of over 0.2 V across cells is found to be possible. Furthermore, rapidly changing the inlet temperatures to simulate a potential battery management system failure indicated the risk of some cells in the pack exceeding the desired cut-off voltage. The present framework can be used to design battery packs with effective thermal management strategies, enhancing the overall reliability and performance of battery systems.