Adsorption and diffusion mechanism of hydrogen atom on the Li2O (111) and (110) surfaces from first principles calculations

Abstract The adsorption and diffusion of H atoms on (111) and (110) surfaces of Li 2 O lithium ceramics were investigated by the first principles method based on the density functional theory. The formation energies of these two surfaces were 0.546 J/m 2 and 0.781 J/m 2 , respectively, which are a little smaller than those obtained by others. Combined with the adsorption energy, local electronic density of states, Bader charge analysis and charge density, we found that H atoms have three kinds of adsorption type on these two surfaces: physical adsorption, weak chemisorption and chemisorption. Comparing the diffusion barrier of H atoms on two surfaces, it is found that H atoms need to overcome over a barrier about 1.0 eV from top O atom to bridge site of two top Li atoms on (111) surface by CI-NEB. It is easier for the H atom to diffuse on the (110) surface with the diffusion barrier not to exceed 1.0 eV.