Deformation and failure properties of cylindrical battery packs under quasi-static and dynamic indentations

Abstract

Battery packs, serving as the primary power source in electric vehicles, are essential components; however, their failure behavior under common side collisions—particularly those involving localized dynamic loads and repeated impacts—remains insufficiently understood. This paper investigates the deformation and failure behavior of two battery packs configured in triangular and checkerboard arrangements (T-battery and C-battery packs) through quasi-static indentation, dynamic impact, and repetitive impact experiments. The results indicate that under quasi-static indentation, T-battery packs deform in a "triangular mode", while C-battery packs deform in a "rectangular mode", resulting in a more generous failure displacement for C-battery packs. With the increase of impact velocity, the battery pack exhibits a pronounced strain rate effect, with a progressive transition from extrusion failure to brittle fracture. This transition is characterized by bending fractures in T-battery packs and internal jellyroll cracking in C-battery packs. Additionally, repeated impact experiments reveal that T-battery packs demonstrate superior impact resistance compared to C-battery packs. A power-law relationship between single impact energy and the number of impacts was established, providing a means to predict the failure energy threshold for battery packs.