Abstract
Pouch type lithium-ion battery (LIB) has now been widely used in electric vehicles, smartphones, computers and et al. Mechanical abuse is one of the main reasons to cause the safety issues for lithium-ion battery. The highly accurate and efficient computational model is helpful for the safety design, application and analysis of LIB. The previous homogenized mechanical models of the pouch LIB use different material parameters for various loading conditions. Herein, we establish an anisotropic homogenized method to predict the mechanical behavior in in-plane and out-of-plane directions simultaneously. Engineering constants and Hill's 48 criteria are used for the anisotropic properties, and bilinear plastic model is used as the hardening curve under large deformation. Based on this method, we established two homogenized models i.e. one-layer model and multi-layer model. Experiments in various loading conditions including 3-point bending (length direction and width direction), out-of-plane compression, and in-plane compression (length direction and width direction) are conducted for parameters calibration. The calibration methods are then discussed and confirmed through these experiments. The computational models show good correlation with experiments both in in-plane and out-of-plane directions. The difference is that the global buckling behavior can be predicted by both of the two models, while the local buckling can only be predicted by the multi-layer model. The results may shield light on the safety design, application and analysis for pouch LIB.
Representative volume element model of lithium-ion battery electrodes based on X-ray nano-tomography