As one of the commonly used power sources for electric vehicles, cell phones, and laptops, the safety of lithium-ion batteries (LIBs) has aroused more and more attention. Lithium-ion batteries will inevitably suffer from external abuse loading, triggering thermal runaway. Nail penetration is one of the most dangerous external loading methods, so it is meaningful to study the failure behaviors under this loading condition. In this paper, the experimental study of lithium-ion batteries under axial nail penetration is carried out. The lithium-ion battery studied here is commercially available 18650 cylindrical battery with a nickel cobalt aluminum oxide (NCA). Force, temperature and voltage data are recorded synchronously to learn its mechanical, thermal and electrochemical behaviors. Then, the loading velocity effect is discussed, results show the loading velocity has no obvious effect on failure properties of lithium-ion battery. Besides, deformation and failure properties of lithium-ion battery are discussed in detail. A simple homogenous computational model is established to predict the mechanical responses of the battery. The partial detailed model is also established to explore the failure mechanism. The batteries are disassembled after loading to better understand the failure morphologies. Two failure modes are discovered through experiments and computational model. The findings can contribute to a better understanding of the failure mechanism of lithium-ion battery under axial nail penetration, provide reference for battery safe design.