Tailoring nanostructured materials based on y-graphyne monolayers modified with Au heteroatoms for application in energy storage devices: A first principle study

Pristine y-graphyne (y-GY) is a widely known two-dimensional system that has a high Li, Na, and K adsorption capacity with high energy barriers for the diffusion of such metal ions. In this work, we used dispersion corrected density functional theory calculations to investigate the electronic effect of Au-doped y-graphyne (GYE-Au and GY-Au) monolayers on the adsorption and diffusion of M metal-ions (M = Li, Na, and K). The nature of the electronic structure of the GYE-Au monolayers corresponds to a semi-metallic behavior. According to climbing image nudge elastic band calculations, low activation energies in the diffusion of M atoms are associated with the presence of the Au atom with respect to the y-GY monolayer. High adsorption energy values were associated with the storage capacity of the GYE-Au monolayers. The electronic storage properties such as open circuit voltage and theoretical specific capacity were improved in the GYE-Au monolayers. This study shows that, at an atomistic level, the GYE-Au monolayers could be an excellent 2D anode material for Li, Na, and K-ion batteries.