Dynamic crashing behaviors of prismatic lithium-ion battery cells

Abstract

With rapid rising use of lithium-ion batteries (LIBs) for electric vehicles (EV), the mechanical behaviors of LIBs have become more and more important to crash safety. This study aims to investigate dynamic crashing characteristics of prismatic LIB cells through compression tests and finite element (FE) modeling. First, the in-plane and out-of-plane constrained compressive tests of battery specimens without electrolyte are performed at various strain rates to characterize mechanical behaviors of LIB cells under the dynamic loading conditions. The experimental results indicated that the strain rate was of significant effect on the in-plane constrained compression tests but insignificant effect on the out-of-plane counterparts. The nominal stress–strain curves obtained from the dynamic in-plane loading conditions are generally higher than those from the quasi-static conditions. The nominal stress–strain curves obtained from the experimental tests were used to develop homogenized material models for the LIB cell components subject to dynamic crashing conditions. Second, the FE models for the prismatic LIB cell were created by incorporating the homogenized material model. The simulation results were compared with those obtained from in-house experiments including the in-plane and out-of-plane indentation tests on the LIB cell specimens, which exhibited fairly good agreement. Finally, based upon the validated FE models of LIB cell, the indentation of entire prismatic LIB was simulated to further characterize the mechanical behavior of the Lithium-ion batteries under dynamic crushing. The established FE models are anticipated to provide a useful approach for crash safety design in the LIB packs for different impact accidents of electric vehicles.