The wetting properties of Li droplet on Cu surfaces: A molecular dynamics study

The wettability of liquid lithium (Li) droplet on different copper (Cu) surfaces has been studied with molecular dynamics (MD) simulations. The contact angles, solid-liquid interface structures and the time-dependent radius of Li droplet on Cu surfaces are analyzed. A precursor film with single atomic thickness is observed on the Cu surfaces. The precursor film on Cu (100) and (111) surfaces presents a perfect circle, but an oval shape on Cu (110) surface. The spreading kinetics of the precursor film on Cu (111) surface is much faster than that on Cu (100) surface, which is attributed to the lower diffusion barriers of Li atom on the Cu (111) surface. The smallest contact angle is for Li droplet on Cu (111) surface and the biggest one is along the [001] orientation of Cu (110) surface where no precursor film exists. Besides, the temperature effect on the wettability is also studied, and Li droplet spreads more sufficiently with increasing temperature. (C) 2016 Elsevier B.V. All rights reserved.