B12@Li20N12: A nanostructured material with lightweight elements as hydrogen storage medium

Abstract

The surging interest in hydrogen energy, regarded as a sustainable and environmentally responsible substitute for conventional fossil fuels, underscores the demand for proficient hydrogen storage materials. In this study, based on density-functional theory calculations, we predict a symmetric configuration, known as Ih-symmetry B12@Li20N12, predominantly comprised of lightweight elements. The structure exhibits no imaginary frequency upon analysis of its vibrational frequencies, thus indicating its kinetic stability. Molecular dynamics simulations indicated that the structure can be maintained up to 800 K. The structural stability can be attributed to the existence of 46 multi-center two-electron σ bonds. In addition, it is noteworthy that the B12 @Li20N12 structure has the capability to absorb approximately 62 H2 molecules, exhibiting an average adsorption energy of − 0.20 eV/H2, a value that falls between physical and chemical adsorption. The corresponding gravimetric hydrogen density is 14.3 wt%, making the B12 @Li20N12 structure a potential hydrogen storage material. Ab initio molecular dynamic simulations for the hydrogen-absorbed B12 @Li20N12 structure reveal its potential for hydrogen storage under near-ambient condition.