Atomic scale analysis of the corrosion characteristics of Cu-Li solid-liquid interfaces

Highlights: • The interfacial alloying occurs in the corrosion process. • The change of interface composition leads to the change of diffusion properties. • The corrosion process is anisotropic. • Surface stability of the substrate material causes the anisotropy of corrosion. The corrosion characters of Cu(001)-Li, Cu(110)-Li and Cu(111)-Li solid-liquid interfaces are investigated using molecular dynamics (MD) simulations. The interfacial structure and properties are studied through various quantitative characterizations. In the corrosion process, the interfacial alloying is observed via the analysis of fine-scale density profile. And the structure of the alloying layer still maintains the in-plane structure of corresponding Cu crystal plane. Because the interfacial alloying has changed the components of interfacial layers, the diffusion properties of atoms are different between the alloying layer and pure liquid Li layer. As a result, the alloying layers are more stable than pure liquid Li layers. In addition, the temperature effect on the interfacial structure and property suggests that the corrosion process is anisotropic, which is quantified by the penetration depth of Li atoms and the loss rate of Cu atoms. Specifically, the corrosion behavior is most easy to occur at the (110) interface, and most difficult at (111) interface. The anisotropy of the corrosion process is well explained in terms of the stability of Cu atoms on the substrate surface. As an important content of research, the concentration of dissolved Cu atoms in liquid Li is also measured by us.