An Approach to Selection and Evaluation of Battery Enclosure Materials for Electric Vehicles

Finding the most proper materials for electric and hybrid vehicle battery enclosures is vital to achieving a balance between protection, weight, cost, and safety performance. This study proposes a novel material selection methodology focusing on three commonly used materials: stainless steel, aluminum (Al), and carbon fiber reinforced polymer (CFRP). Mathematical approaches are presented for material evaluation for battery enclosures for two different scenarios. Battery enclosures fabricated from these materials are evaluated under different scenarios using a trade-off strategy and the penalty function approach. The first scenario considered mass and cost minimization, where aluminum demonstrated superior overall performance, closely followed by CFRP, while stainless steel underperformed. The second scenario introduced maximizing specific energy absorption (SEA) as a third objective. Within the scope of this study, an exchange constant (a₃) that contains a collision scenario is obtained. In the second scenario, although aluminum remains optimal at moderate collision speeds (approximately 60 km.h-1), CFRP outperforms aluminum at higher collision speeds (over 100 km.h-1), owing to its enhanced energy absorption characteristics. Given that severe battery enclosure damage typically occurs above 90 km.h-1, CFRP emerges as the preferred material when accounting for collision safety alongside electromagnetic interference (EMI) shielding and thermal runaway performance advantages. These findings highlight CFRP’s suitability for battery enclosures in applications demanding high safety standards and efficiency. In addition, the current study mathematically demonstrates the advantages of CFRP battery enclosure under potential collision scenarios.