Analysis of Electro-Thermal Hot Spot Formation in Li-Ion-Battery-Cells

W. Beckert[1], C. Freytag[1], T. Frölich[1], G. Fauser[1]
[1]Fraunhofer IKTS, Dresden, Germany

The presented model approach offers a computational efficient tool to analyze the influences of geometrical design details, material selection and operational conditions on the electro-thermal behavior of a full Li ion battery cell geometry. It considers typical aspects as anisotropic winding structure, electro-thermal coupling and nonlinear electrical characteristics for moderate computational costs. That becomes possible by employing elaborate model reduction strategies, taking full advantage of the flexible features offered by the COMSOL Multiphysics® code: using an homogenized 3 DOF phase composite model for electric and thermal conduction in the cell laminate, a simple empirical, experimental based, submodel for the electro-chemical characteristics and a hybrid coupled 2D-3D approach for the electrical and thermal interactions in the winding body.