Organic-inorganic composite film enhances antioxidation and corrosion resistance of lithium battery copper foil

Preventing high-temperature oxidation and enhancing corrosion resistance are crucial factors influencing the quality of copper foil in lithium-ion batteries and their overall service life. The development of chromium-free antioxidation systems has gained significant attention due to their environmental advantages. In this study, we formulated an antioxidation liquid composed of polyvinyl alcohol (PVA), nano-silica(nano-SiO 2 ), and citric acid (CA), and applied it to copper foil using a chemical impregnation process. Various characterization techniques, including scanning electron microscopy (SEM), Tafel curves, X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and electrochemical impedance spectroscopy (EIS), were utilized to investigate the microstructure, antioxidation properties, and corrosion resistance of the treated copper foil. The results demonstrate that with a PVA concentration of 4 g/L, nano-SiO 2 concentration of 7 g/L, and CA concentration of 5 g/L, the treated copper foil exhibits excellent resistance to high-temperature oxidation and corrosion. Specifically, under conditions of 140℃ for 15 min, the surface of the copper foil remains largely unchanged, and the corrosion resistance efficiency can reaches 75.49 %. The study reveals a trend of cross-linking between PVA and CA, which rapidly forms a protective film on the copper foil surface. Nano-SiO 2 acts as a filler, mitigating defects and enhancing the density and robustness of the film. This chromium-free, environmentally friendly antioxidation process aligns with sustainable development principles and offers new insights for advancing chromium-free antioxidation technologies.