Experimental and modeling analysis of the formability of PET/PA/Al/PP laminated composite pouches for Li-ion Batteries

The metal-polymer laminate pouch film is a vital component in lithiumion batteries (LIBs) for electric vehicles (EVs), offering protection for electronic components and enabling compact stacking to maximize cell capacity. Ensuring and optimizing battery performance requires a thorough understanding of the pouch film’s formability. This research examines the formability of aluminum-based pouch films composed of PET, PA, Al, and PP layers, with a focus on the mechanical properties of each layer and the adhesion between polymer and metal interfaces. The study employs mechanical, adhesion, formability, and cup drawing tests to analyze the deformation behavior of the laminated film. A finite element (FE) model, incorporating an anisotropic plasticity model and a cohesive zone model (CZM), is applied to elucidate the deformation mechanisms and derive the elastic-plastic properties of the individual layers, integrating them into a cohesive multi-layer system. The relationship between layer deformation, interface damage, and overall formability is explored through experiments and FE simulations. Validation through square cup drawing experiments highlights the critical role of adhesion strength in determining the film’s formability. Furthermore, the study demonstrates that PET and PA polymer layers enhance formability when combined with thin metallic foils.