Development and validation of a simplified quantification model for thermal propagation of prismatic cell-to-pack cells

With the phasing out of internal combustion engine vehicles from 2035 in the EU, battery electric vehicles (BEV) are becoming more in focus to achieve an important step towards a zero-emission transportation sector.[1] Current challenges for BEVs are fast-charging capabilities and safety as well as range is a much discussed topic.[2] One way to increase the range is to reduce the amount of inactive materials at the pack level and thus increase the energy density of the pack. The current standard is a pack design, in which battery cells are packaged into modules and then connected.[3] The cell-to-pack design approach aims to integrate the battery cells, which are growing in size, directly into the pack, saving the module level and potentially increasing pack level energy density by 15-25 %.[4] However, one challenge of this pack architecture is the elimination of protective modules and the resulting increased safety requirements for the cells. Since multiple norms and standards must be fulfilled on module and pack level to ensure vehicle safety, this work deals with the integration of the required propagation protection into a prismatic cell housing designed for a cell-to-pack application. This is intended to reduce complexity and assembly steps at the pack level, make propagation protection more efficient, and achieve potential cost savings. For the development of a cell design with integrated propagation protection, a simplified quantification model is conducted, which provide the possibility to estimate multiple parameters, (e.g., energy transfer rates during propagation). Based on this model, a cell design will be developed, validated and evaluated. This works presents the reasons leading to the developed model. Furthermore, approaches of the simplified quantification model will be showed, such as influencing factors of the thermal propagation and first calcu lations.