Compressive Behavior of Representative Volume Element Specimens of Lithium-Ion Battery Cells under Different Constrained Conditions
Shin-Jang Sung, William Lai, Jwo Pan, Yusuf Ali (Ford) and Saeed Barbat (Ford)
The compressive behavior of lithium-ion phosphate battery cells is investigated by conducting in-plane constrained compression tests of representative volume element (RVE) specimens. The results for cell RVE specimens under in-plane constrained compression tests without pre-strains and with pre-strains in the out-of-plane direction indicate that the load carrying capacity is characterized by the buckling of cell specimens. As the pre-strain increases, the nominal compressive stress-strain curve becomes higher. Based on the elastic buckling analyses for a beam with different lateral constraints due to different pre-strains in the out-of-plane direction, the number of half waves and the buckling stresses were obtained. The results indicate that the number of half waves and the buckling stress increase as the pre-strain increases. The general trends of the numbers of half waves and the buckling stresses agree with those obtained from experiments.
Figure 1. A schematic of (a) a pouch cell and a cell RVE specimen for the in-plane constrained compression test, (b) a cell RVE specimen with the dimensions, and (c) a side view of a small portion of the cell RVE specimen showing the individual cell components. The large red arrows indicate the compressive direction.
Figure 2. Deformation pattern of a cell RVE specimen after the in-plane constrained compression test the out-of-plane compressive pre-strains of (a) 0% and (b) 3.2% at the in-plane compressive strain of 38% and 36 %, respectively.
Figure 3. The in-plane nominal compressive stress-strain curves of four cell RVE specimens with the out-of-plane compressive pre-strains of 0%, 3.2% and 11%, tested at a displacement rate of 0.5 mm/min (nominal strain rate of 0.0003 s-1).
- S.-J. Sung, W.-J. Lai, M. Y. Ali, J. Pan and S. Barbat, 2014, “Compressive Behavior of Representative Volume Element Specimens of Lithium-Ion Battery Cells under Different Constrained Conditions,” SAE International Journal of Materials and Manufacturing 7(2), pp. 480-487. DOI: 10.4271/2014-01-1987. (SAE 2014-01-1987)