Explicit Dynamics Analysis of the Impact Response of Lithium‐Ion Cells

ABSTRACT

It is very important to make sure that EV lithium‐ion cells are safe when they are abused, like when they are hit or crushed. This kind of loading can cause structural failure or thermal runaway. Even though FEA is used a lot, common practices make the jellyroll the same and ignore the fact that the electrolyte is a moving fluid. In ANSYS LS‐DYNA, we use a coupled FEM–SPH approach. FEM is used for solid parts, and SPH is used for the electrolyte, which is modeled as a weakly compressible fluid. This lets us see fluid–structure interaction under large deformation. Separating solids and liquids makes it easier to understand how pressure waves move, how casings deform, and how stress builds up inside an object during impacts. When a prismatic cell is hit from the side, simulations show strong Von Mises stresses in the casing near the point of contact. Over time, these stresses spread out, making some areas weaker. At the same time, SPH shows high‐pressure areas and shock transmission in the electrolyte, which are closely related to how the casing responds. This means that moving fluid increases boundary stresses. Frame‐by‐frame analysis shows that electrolyte displacement moves loads to structural interfaces, which speeds up the collapse. This combined model takes into account both coupled mechanics and internal fluid dynamics, which are often missed in studies that only use FEM. This makes it easier to predict failures and design safer batteries. Future research should integrate mechanical abuse with electrochemical degradation and thermal feedback to attain a comprehensive safety evaluation.