Coupled Electrochemical-Mechanical Modeling of Lithium-Ion Batteries Using Distributed Randle Circuit Model

Electric vehicles contain hundreds of high energy density lithium-ion batteries. Crashworthiness of these vehicles can be improved by better understanding the response of these batteries in an event of accident or abusive loads. These loads can induce short-circuit and thermal runway in extreme cases. Therefore, an efficient finite element model of a battery which can precisely predict the coupled multi-physics behavior of a cell is highly desired, especially in large-scale simulations. Homogenization approach in finite element modeling where the layered structure of a cell is considered as a uniform medium, reduces the computational cost significantly. In this paper, an Equivalent Circuit Model with distributed Randle circuit parameters is coupled with a homogenized mechanically well-calibrated material model to simulate the coupled mechanical-electrical loadings for a pouch cell. First, a parameter identification process is done using the experimental measurements of cycling and pulse tests. Then, the model used in various local indentation simulations. The onset of short-circuit as well as the load-drop has been captured precisely. This coupled multi-physics model and the calibration procedure presented in this study can benefit the electric vehicle and battery related industries with efficient homogenized modeling especially where the detailed modeling of the cells is not feasible.