Abstract: The deformation failure of the interior of the prismatic lithium-ion cell is the main factor leading to internal short circuit and thermal runaway. Based on the mechanical tests of the internal components of prismatic lithium-ion cell, a mesoscale layered element model of separator, cathode, separator, anode stacking was constructed. The simulation results under different loading conditions show that the layered element model can effectively characterize the macroscale mechanical response and mesoscale deformation failure. Furthermore, a layer-stacking coupling model is constructed by connecting the layered element model with the homogenization model, and the computing architecture of the model is defined. The simulation results of the prismatic lithium-ion cell show that the layer-stacking model can predict the force-displacement curve and internal short circuit under local load. In addition, different peak loads appear in the layer-stacking model with different separator material models. This modeling method not only improves the calculation efficiency of the refined model by 75%, but also increases the in-depth understanding of the mechanical internal failure, which has guiding significance for improving the safety design of prismatic lithium-ion cell.

Key words: prismatic lithium-ion cell, mechanical response, deformation failure, mesoscale layered element, layer-stacking model