不同挤压载荷下圆柱形锂离子电池的失效机理试验研究

To meet the requirements of crashworthiness design of electric vehicle power battery packs, the failure mechanism of lithium-ion batteries was studied under different mechanical abuse conditions. Based on local indentation and plane compression loading tests on three different capacity NCR18650 cylindrical lithium-ion batteries, the force-electric-thermal responses of lithium-ion batteries were analyzed and the cross-section failure modes of the compressed battery samples were given. Then the effects of loading types and battery capacity on the failure mechanism of cylindrical batteries were discussed. The results show that internal short circuit and external short circuit failure modes of batteries may be caused by local indentation and plane compression, respectively. With the increase of battery capacity, the bearing performances of the batteries may reduce, which leads to the failure displacements decrease. Loading types and rated capacity also have an effect on the surface temperature changes of the batteries. The maximum surface temperature of the batteries after the local indentation is higher, and the surface temperature changes of the medium-capacity batteries are relatively smooth.