Growth process of molybdate conversion coating on the surface of aluminum foil and its adhesive mechanism

Abstract

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.

Strategies towards inhibition of aluminum current collector corrosion in lithium batteries

“…The use of conversion materials to improve the corrosion resistance of Al foils has been widely applied in electronics, aerospace, and batteries [206,207] . The chromate conversion coating (CCC) on the surface of the Al current collector was pretreated by Piao et al to suppress Al corrosion in the LiTFSI-based electrolyte [27] .…”

Low‐temperature performance optimization of LiFePO4‐based batteries

“…At present, the main technical route is to evenly pre-coat conductive carbon nanolayers (such as conductive carbon black or graphene) on both sides of the aluminum foil. 22,23 Carbon-coated aluminum foil is to evenly and exquisitely coat conductive nanocarbon materials on aluminum foil. The coating thickness of a conductive carbon layer with good adhesion is relatively thin and controlled within 1 μm.…”

“…It is a breakthrough technological innovation to use functional coating to treat the surface of conductive substrate. At present, the main technical route is to evenly pre‐coat conductive carbon nanolayers (such as conductive carbon black or graphene) on both sides of the aluminum foil 22,23 . Carbon‐coated aluminum foil is to evenly and exquisitely coat conductive nanocarbon materials on aluminum foil.…”

Vanadium and Tannic Acid-Based Composite Conversion Coating for 6063 Aluminum Alloy

“…Nevertheless, its utilization has been banned by relevant environmental directives due to hexavalent chromium [Cr (VI)] in the conversion solution and the coating has a wide toxicity to human health and ecological environment (Lay and Levina, 1998;Zhitkovich et al, 2000;Quievryn et al, 2003;Nordberg et al, 2007). As a consequence, various non-chromate conversion coatings have been exploited in the last few decades, including phosphate (Shida et al, 2003;Sheng et al, 2010), molybdate (Huang et al, 2019;Chen and Xu, 2021), rare-earth metal salts (Aziz et al, 2011;Zuo et al, 2014), vanadate (Vega et al, 2011;Niu et al, 2014), and zirconate and/or titanate (Lunder et al, 2004;Guan et al, 2011;Yi et al, 2012;Zuo et al, 2015).…”