Analysis of Thermal Behavior of Li-Ion Battery based on Multiphysics Model

Heat management is a critical issue encountered during the operation of a battery cell, module and pack. In this study, we presented a heat model of a lithium-ion cell that is suitable for predicting battery thermal behavior. The heat generation and dissipation terms were classified for both irreversible and reversible heat. Additionally, the irreversible heat was formulated according to Joule-heating with internal resistance to avoid the calculation of electrochemical reactions that require a considerable computational load. Furthermore, the electrical equivalent resistance was determined through EIS analysis, and in this study, the change in its value was investigated using equal intervals of SOC. Moreover, through the analytical approach of the Butler-Volmer equation and ionic conduction equation, the change in the equivalent resistance value was explained and compared with the value obtained experimentally. © 2022 Korean Institute of Electrical Engineers. All rights reserved.