Ab Initio Study of High-Capacity Hydrogen Storage in Lithium-Shrouded Honeycomb Borophene Oxide Nanosheet

Abstract

Here, we investigate the hydrogen storage performance of Li alkali metal-shrouded two-dimensional (2D) honeycomb borophene oxide (h-B3O) using the Tkatchenko–Scheffler method, an accurate and parameter-free method to determine the long-range van der Waals interactions. Each Li atom can strongly bind three H2 molecules to the substrate with an average adsorption energy of −0.22 eV/H2, and the theoretical weight density of the Li-shrouded h-B3O structure can reach 9.84 wt %. In particular, a maximum hydrogen storage capacity of 12.71 wt % is achievable by moderately increasing the external pressure. Lattice thermal conductivity calculations show efficient thermal transport and good adsorption/desorption behavior of H2 molecules. Furthermore, the study of possible defects in the material showed that the hydrogen storage performance of the Li-shrouded h-B3O nanosheet is insensitive to the presence of defects in the material, which has important implications for its experimental synthesis. Our findings indicate that Li-shrouded 2D h-B3O is a promising material for reversible H2 storage.