Side pole crash performance of battery electric vehicles

• A comparison of EV and ICE vehicles structures and implications • Occupant Protection in EVs vs ICE vehicles • Effects of structural design on range and energy efficiency of EVs Battery Electric Vehicles (BEVs) are gaining widespread popularity due to their cost-efficient operation and lower carbon emissions compared with Internal Combustion Engine (ICE) vehicles. However, despite their numerous advantages, BEV sales remain below forecasts and target adoption levels, primarily because of limited driving range, which contributes to customer anxiety. Research aimed at increasing BEV range has largely focused on improving battery-cell energy density. Yet, the additional structural mass required to protect battery packs and maintain their integrity during crashes can substantially reduce energy density at the pack and system levels. This study investigates the effects of added battery-pack protective structures on both vehicle driving range and occupant protection. The results show that BEVs are consistently heavier (by an average of 278 kg) and stiffer than ICE vehicles. Consequently, the increased mass and stiffness lead to higher accelerations transferred to the passenger compartment (e.g., a peak acceleration of 69.51 g for a BEV versus 55.80 g for an ICE vehicle at the B-pillar) and to lower system-level energy density. Overall, statistically significant correlations are observed between increased vehicle mass and decreases in occupant protection metrics and driving range. These findings suggest opportunities to optimize battery protective structures to minimize non-functional mass and reduce stiffness while maintaining occupant safety.