Clay-like mechanical properties for the jellyroll of cylindrical Lithium-ion cells

In this investigation, several quasi-static mechanical tests on cylindrical Lithium-ion battery cells are performed to reveal the essential mechanical properties of the jellyroll. Utilizing the plastic flow rule, it was found that the homogenized mechanical properties of the jellyroll are similar to the clay (clay-like). According to the mechanical characteristics of clay, a linear equation was proposed to describe the nonlinear constitutive behavior of the jellyroll. An explicit finite element model for the jellyroll that could accurately predict its mechanical response during deformation using crushable foam constitutive behavior was established in HyperWorks/LS-DYNA to validate the proposed approach. The simulation results of various loading cases are in good agreement with the corresponding experimental results. By proposing a micro stress area, the stress-strain relations for components of the jellyroll were calculated individually. A finite element model was developed to compare the mechanical properties of the jellyroll by changing the thickness of different components, including the metal foils and the active particles. The simulation results indicate that the change of the thickness of the coating active particles will influence the mechanical properties of the jellyroll.