Research on the Impact Resistance of Sandwich-Structured Battery Pack Protective Plates

With the continuous development of the new energy vehicle industry, in order to further improve the safety and range of electric vehicles, vehicle lightweighting has been a key focus of major car companies. However, research on lightweighting and the impact protection effect of battery pack protective plates is lacking. The bottom protective plate of the battery pack in this study has a sandwich-type multi-layer structure, which is mainly composed of upper and lower glass-fiber-reinforced resin protective layers, steel plate impact resistant layers, and honeycomb buffer layers. In order to study the relationship between the impact damage response and material characteristics of the multi-material battery pack protective plate, a matrix experimental design was adopted in this study to obtain the energy absorption ratio of different material properties when the protective plate is subjected to impact damage. This work innovatively used a low-cost equivalent model method. During the drop hammer impact test, a 6061-T6 aluminum plate in direct contact with the lower part of the bottom guard plate test piece was used to simulate the deformation of the water-cooled plate in practical applications. High-strength aluminum honeycomb was arranged below the aluminum plate to simulate the deformation of the battery cell. This method provides a scientific quantitative standard for evaluating the impact resistance performance of the protective plate. The most preferred specimen in this work had a surface depression deformation of only 8.44 mm after being subjected to a 400 J high-energy impact, while the simulated water-cooled plate had a depression deformation of 4.07 mm. Among them, the high-strength steel plate played the main role in absorbing energy during the impact process, absorbing energy. It can account for about 34.3%, providing reference for further characterizing the impact resistance performance of the protective plate under different working conditions. At the same time, an equivalence analysis of the damage mode between the quasi-static indentation test and the dynamic drop hammer impact test was also conducted. Under the same conditions, the protective effect of the protective plate on impact damage was better than that of static pressure marks. From the perspective of energy absorption, the ratio coefficient of the two was about 1.2~1.3.