Development of a simplified model to quantify thermal propagation in direct integration concepts for prismatic cells

In view of the limited availability of raw materials in Europe, especially in Germany, the complete electri fication of the transport sector requires innovative technologies that are both efficient and save resources. In addition to ongoing research on alternative battery technologies, optimizing the integration of lithium ion battery cells (LIB) in battery systems plays a key role. Original equipment manufacturers (OEMs) are exploring novel concepts to maximize the energy density of battery systems. A significant example of this is the transition to a "cell-to-pack" architecture, which in theory allows for a 15-20% increase in energy density by removing modular structures and their supporting elements.
However, these concepts have primarily been implemented with the safer lithium iron phosphate (LFP) cell chemistry, which, on the other hand, has a lower capacity and thus compensates for the intended increase in energy density. A promising approach would be to integrate high-energy cathode cell chemistry, such as nickel-manganese-cobalt oxide (NMC) 811, into a direct integration concept, which could potentially lead to a further increase in energy density and thus to higher ranges for battery electric vehicles. In addition, a reduction in the number of battery cells per vehicle would be conceivable, which would significantly reduce weight, costs and resource consumption. However, one crucial challenge in this packaging architecture is the elimination of protective modules, which increases the safety requirements for the cells in the event of an accident.
To support the development of such direct integration concepts, advanced simulation models are beneficial as they help to reduce costs and development time. However, current models are limited for industrial applications for the design of propagation protection due to their high complexity and limited adaptability. These limitations are particularly apparent when cell chemistry or other relevant parameters change. The present work therefore deals with the development of a simplified quantification model for thermal propa gation, which should help to accelerate the development of direct integration concepts. The poster presents initial approaches and results of the model.