Density functional study of metal lithium atom adsorption on antimonene

Abstract

<sec> Since the discovery of graphene, researchers have been being increasingly attracted by the emerging of a bunch of two-dimensional (2D) materials, such as BN, MoS₂ and black phosphorene. These materials possess outstanding physical and chemical properties, which could find great potential applications in nanoelectronics, energy conversion or storage, photocatalysts, etc. Recently, a theoretically predicted pucker layered material consisting of Sb atoms, antimonene, has been prepared, and is attracting the attention in the field of lithium ion batteries. </sec><sec>In this paper, based on first-principle density functional theory, the adsorption characteristics of Li atoms on antimony are studied, including the most stable adsorption configuration, the adsorption density and the diffusion path of Li atom on antimonene. The results show that the most stable adsorption configuration of Li atom is in the valley site, i.e. the center of the three Sb atoms in the top layer and one Sb in the bottom layer. The adsorption energy is 1.69 eV and the adsorption distance is 2.81 Å. The band structure shows that antimony is an indirect band gap semiconductor with a band gap of 1.08 eV. After the absorption of Li atom, the Fermi level enters into the conduction band, which shows an electronic property similar to metal. The analysis of density of states shows that the p-electronic state of Sb atom and the p and s electronic state of Li atom possess distinct resonance peaks, showing hybrid bonding characteristics. With the increase of the number of Li atoms adsorbed, the lattice structure and electronic structure of antimonene change greatly. The nudged elastic band calculation shows that the diffusion barrier of Li atom on antimony surface is 0.07 eV, and a smaller barrier height is beneficial to the rapid charge-discharge process. To sum up, antimony has a good potential as an anode material for lithium ion batteries.</sec>