No Propagation - Safety Target for Premium Battery Systems

Authors

Dr. M. Stapelbroek, A. Averberg, R. Beykirch, FEV Europe GmbH, Aachen; H. Sonntag, FEV eDLP GmbH, Sandersdorf-Brehna; F. Elsner, A. Sauer, F. Pampel, RWTH Aachen University:

Year

2022

Print Info

Production/Publication ÖVK

Summary

Battery systems for vehicles with electrified powertrains must achieve ever higher energy densities while maximizing safety and reducing costs to offer customers the highest driving ranges at affordable prices. Higher energy densities at system level are achieved by new battery cells and higher packing densities with e.g., cell-to-pack or cell-to-chassis approaches. But higher energy densities also lead to significantly more reactive cell chemistries and larger cell formats. This increases the risk of battery fires occurring as a result of manufacturing defects in the cell or operating faults. The severity of a so-called “Thermal Runaway” increases as the reactivity of the cell increases. At the same time, the requirements for passive safety up to "Stop Propagation" or even "No Propagation" are continuously increasing. To achieve these goals, close integration of development and testing is required.

On this topic, FEV has developed and combined multiphysics and fluid dynamic models that help to reduce the development time of lithium-ion battery systems and to define a safe system as early as possible in the process. Initial cell tests generate the necessary input data for the simulation models. Subsequently, various measures for optimizing the thermal propagation behavior can be tested virtually. The accuracy of the models can be further optimized by cascaded test series with different cells, materials as well as venting systems and at cell level, in the cell compound, in the module, in the module compound as well as in the overall system. The chosen approach ensures the validation of the thermal propagation homologation test at the earliest possible stage of development. In this way, it was possible to develop an effective solution methodology for "Stop Propagation".

ISBN

1920-2323-23-1

Number of pages

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