Computational models for simulations of lithium-ion battery modules under quasi-static and dynamic constrained compression tests

A computational model is developed for simulations of representative volume element (RVE) specimens of lithium-ion battery modules under in-plane constrained compression tests. The model is based on the mechanical properties of the heat dissipater, the foam and the macro behaviour of the cell under quasi-static loading conditions. The semi-homogenised computational model allows for computational efficiency with sacrifice of the detailed buckling behaviour of the battery cell components. The results from the model under quasi-static and dynamic loading conditions are compared to those from experiments. The nominal stress-strain responses of the specimen and the deformation patterns of the heat dissipater obtained from the computational results compare fairly well with the experimental results. Both experimental and computational results show that for the given dynamic displacement rates the nominal stress at which the heat dissipater begins to buckle under dynamic loading conditions is about twice as high as that under quasi-static loading conditions and that the nominal stresses at large nominal strains under dynamic loading conditions are slightly higher than those under quasi-static loading conditions. The results of this investigation suggest that when a less detailed model is used for simulations under crash conditions, the higher initial buckling stresses should be considered.