Titanium conversion coatings on the aluminum foil AA 8021 used for lithium–ion battery package

• Published in: Applied surface science 2017-10, Vol.419, p.447-453
• Main Authors: Xia, Xu-Feng, Gu, Ying-Ying, Xu, Shi-Ai
• Format: Article
• Language: English
• Subjects: Al foil; Bonding mechanism; Peeling strength; Titanium treatment
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2017.03.040

[Display omitted] •An environment-friendly Ti conversion coating was prepared on the Al foil.•The wettability of Ti conversion coating was investigated by contact angle test.•Ti treatment can significantly improve the corrosion resistance and peeling strength of Al/P composites. In this study, an environment-friendly titanium (Ti) conversion coating was successfully deposited on the aluminum foil AA 8021 in the solution containing hexafluorotitanic acid (H2TiF6), and its morphology, composition, growth process, hydrophilicity and corrosion resistance were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), energy dispersive spectroscopy (EDS), X-ray photoelectric spectroscopy (XPS), contact-angle measurements (CAM) and salt spray exposure. The peeling strength between the Ti treated Al foil and the modified polypropylene (PP) film (PP grafted with maleic anhydride, PP-g-MAH) (Al/PP-g-MAH) was measured by T-peeling test. The results show that the Ti conversion coating is a multi-component coating composed primarily of metal oxides (TiO2 and Al2O3) and metal fluoride (AlF3). Ti treated Al foil shows better corrosion resistance than untreated and alkali-cleaned Al foils. The peeling strength of PP-g-MAH film with Ti treated Al foils is approximately 30 times higher than that with untreated Al foils. Thus, Ti treatment is a promising approach to improve the corrosion resistance and peeling strength of aluminum/polymer composite film (Al/P) used in the lithium–ion battery package.