Cylindrical Li-Ion Cell Crush CAE Capability in Automotive Application

The world is moving towards E-mobility solutions and Battery Electric Vehicles (BEVs) are the main enabler towards it. Li-ion cells are the fundamental building block of any BEVs. There are three common types of Li-ion cell design i.e., cylindrical cells, Prismatic Cells and Pouch cells. Ensuring safety of BEVs are critical to gain customer trust and acceptance over Internal Combustion Engine (ICE) vehicles. EV fire is found to be one of the major concerns related to using higher energy batteries. During a crash event, Post-Crash Electrical Integrity of the BEV is to be ensured and hence primary focus is on mitigation of Li-ion cell internal short circuit. It has been seen in prior published articles that cell internal short circuit can be triggered by physical intrusion of cell. This paper primarily focusses on simulating the mechanical behavior of cylindrical cell under various crush conditions. In this paper, we will discuss about the trade-off between Computer Aided Engineering (CAE) model fidelity of cylindrical Li-ion cell & usage of such models in full vehicle crash simulations in LS-DYNA®. Proposed method for Cell CAE model is validated against 3 different crush tests conducted. This approach has shown acceptable accuracy for crushability in all 3 test conditions with reduced modeling complexity when compared with prior published work. Proposed Cell CAE model is found to be compatible in use with full vehicle level crash simulations, thus helps in predicting Li-ion cell intrusion accurately during crash simulations of BEVs.