Crushing Behavior of Vehicle Battery Pouch Cell and Module: A Combined Experimental and Theoretical Study 2018-01-1446

Lithium-ion (Li-ion) batteries are considered as one of the solutions for electric vehicles (EV) in the automotive industry due to their lightweight and high energy density. Their mechanical performance is of great importance for EV crashworthiness design. In this study, quasi-static and dynamic indentation tests were conducted on commercially available vehicle battery pouch cells to investigate their structural integrity. Three indenters, namely, a 19.1 mm (3/4 in.) diameter flat end (FE), a 25.4 mm (1 in.) diameter hemispherical (LH), and a 12.7 mm (1/2 in.) diameter hemispherical (SH), were used to investigate the punch force-deflection responses of the cells. Loading velocity varied in the range of 0.06 mm/s to 3 m/s to test the strain rate effect. Simplified closed-form analysis solutions were developed to predict the pouch cell force-deflection response by considering the effect of compression, tension, and shear of the battery component materials. Good agreement was obtained between the model predictions and test data. Besides the cell level tests, an additional indentation test using a rigid wedge was carried out on a multicell battery module to assess module level damage under large plastic deformation.