EXPLICIT DYNAMIC SIMULATION OF IMPACT IN CYLINDRICAL LITHIUM-ION BATTERIES

High-voltage lithium-ion batteries are increasingly used in electric and hybrid-electric vehicles. Due to a risk of being in an accident, these energy storage systems should be analyzed thoroughly so that the risk of failure or serious damage during accidents is minimized. In this research a three-dimensional finite element simulation of a cylindrical battery cell is performed to study the behavior of the cell under various loading conditions. Li-Ion batteries consist of very thin layers of anodes, cathodes and separators that are packed into a cylindrical-spiral shape. This non-homogeneity nature of the battery cells makes the finite element explicit model very complicated. In this study, a homogenized 3-D model of the cell has been developed that is more suitable for explicit high-strain-rate transient analyses. Another model using layered solid or thick shell elements was generated. For the latter, partially two-phased homogenized material properties were used. Three different configurations are considered to analyze the battery packs: an indentation test with a rigid tube, longitudinal crushing between rigid plates, and transverse crushing. Results from these numerical simulations were consistent for models with thick shell elements and homogenized models.