Silane Film Modification And Corrosion Resistance Of 9μm Electrolytic Copper Foil Surface

Electrolytic copper foil,as the main device of the negative electrode current collector of lithium battery,needs to be passivated on its surface because it has been in a highly corrosive environment for a long time.Most domestic enterprises often use trivalent chromate to convert it,but Cr（III）and Cr（VI）are extremely harmful to the human body and the environment,so it is urgent to explore a new type of environmentally friendly surface treatment process.The silanization treatment technology is a research hotspot in recent years,but the use of a single silane film is limited to a certain extent,and the addition of corrosion inhibitors is one of the ways to improve its performance.The purpose of this paper is to study the corrosion inhibition effect of CeO₂ nanoparticles and Ce（NO₃）₃ as inhibitors added toγ-aminopropyltriethoxysilane coupling agent（APTES）on electrolytic copper foil,and discuss the Ce³⁺modification After the nano-particles,the film layer is resistant to corrosion formation mechanism.The research work is as follows:（1）In this paper,using 9μm electrolytic copper foil as the substrate,orthogonal experiments,and single factor experiments were designed to determine the optimal combination level of each factor,and silane films were prepared on the surface of copper foil.The single silane film layer was characterized by XPS structure,and it was found that there were molecular bonds such as Si-O-Si and Cu/Si O₂ on the surface,indicating that the APTES silane film was coated on the substrate.This was also confirmed by FTIR analysis,meanwhile,unhydrolyzed-OH bonds were found in the film layer.（2）The optimum concentrations of Ce（NO₃）₃ and CeO₂ were determined to be25mg/L and 12.5mg/L,respectively,by electrochemical polarization curves.The modified silane film samples and blank samples（samples without any treatment）were subjected to control experiments to evaluate the corrosion resistance of each film layer.The EIS spectrum results show that the Ce³⁺/CeO₂/APTES hybrid film has a higher modulus and a larger radius arc than the single APTES film,Ce³⁺/APTES film,and CeO₂/APTES film.The fitting parameters show that with the addition of corrosion inhibitor,the R-value increases,the CPE value decreases,and the protective effect is continuously strengthened.In the presence of corrosion inhibitor,the performance of the Ce³⁺/APTES film is slightly stronger than that of the CeO₂/APTES film,but according to the saltwater immersion experiment and electrochemical test analysis,it can be seen that the CeO₂/APTES film has a shielding effect on the medium under long-term immersion relatively weak.Ce³⁺activation of CeO₂ effectively improves the durability of the film.（3）By analyzing the modified CeO₂ particles,the synergistic mechanism of the two corrosion inhibitors was described.XPS,FTIR and XRD showed that Ce³⁺activated CeO₂ formed a Ce-O-Si molecular bond with silane,which was stored in the silane network structure,strengthening the connection between the corrosion inhibitor and silane,and providing excellent corrosion protection.