In this study, an environmentally friendly molybdate (Mo) conversion coating was deposited on the surface of aluminum (Al) foil for use as the packaging film of lithium-ion battery, and the surface morphology and chemical composition were characterized by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). The XPS results show that the conversion coating is composed of MoO 3 , MoO x , Al 2 O 3 , and (MoO 3 ) x (P 2 O 5 ) y . Then, the effects of treatment time on the corrosion resistance of Al foil and the adhesive strength between Mo-treated Al foil and maleic anhydride (MAH)-grafted polypropylene (MPP) were investigated. It is revealed that both the peeling strength and the corrosion resistance of Mo-treated Al foil increase with the treatment time.