Surface treatment and adhesion strength of aluminum foil for lithium-ion battery package

In this study, an environmentally friendly cerium (Ce) conversion coating was deposited onto the surface of aluminum (Al) foil for preparing the packaging material of lithium-ion batteries, and its morphology, composition, and formation mechanisms were investigated using scanning electron microscopy (SEM), atomic force microscopy (AFM), energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The packaging material consisting of six layers was prepared by hot pressing using casting polypropylene (CPP) as the inner layer and maleic anhydride (MAH) grafted polypropylene (mPP) as the inner adhesive. The adhesion properties of untreated and Ce-treated Al foils were characterized by T-peeling test. The results show that Ce conversion coating is mainly composed of cerium dioxide (CeO 2 ) and cerium sesquioxide (Ce 2 O 3 ), and Ce treatment leads to a significant increase in the adhesive strength between Al foil and mPP.