Dynamic Crushing Behaviors of Cylindrical Lithium-Ion Battery Under Multiple Impacts: An Experimental Study

To understand the dynamic failure mechanisms of cylindrical lithium-ion battery (LIB) under different impact loadings, the crushing behaviors of 18650 LIBs were experimentally investigated in this work. The drop weight impact tests with different impactor heads were conducted to analyze the crushing responses of the LIBs. By changing the state of charge (SOC) of the battery, impactor types, and impact energy, the force-electric responses of a LIB under multiple impacts were explored. Macro- and micro-deformation of the batteries were further studied including SOC dependency and the failure modes of the separator. Results show that except for impact energy, the mechanical responses and failure behaviors of the LIBs under repeated impacts also depended upon the SOC and impactor types. The relationship between impact velocity and the minimum impact times was established when a hard internal short circuit (ISC) appeared to evaluate the dynamic safety of the LIBs. These results can provide guidance for the crashworthiness design and safety assessment of the batteries under multiple impacts.