Hydrogen storage capacity of Be-2(NLi)(2) cluster with ultra-short beryllium-beryllium distance

Abstract

Quantum chemical calculations have been carried out to investigate the hydrogen storage capacity of Be-2(NLi)(2) cluster. Calculations reveal that the cluster can take up to eight H-2 molecules reaching a maximum gravimetric density of 21.04 wt%. Six H-2 molecules bind at the Li atoms and two H-2 bind at the Be atoms with moderate binding energy which is required for reversible storage of H-2. Symmetry-adapted perturbation analysis reveals the significant contribution of electrostatic and induction and very minor contribution of dispersion toward the total interaction energy. Molecular dynamics simulations reveal that the H-2 molecules are strongly bound at 77 K and get slowly released at elevated temperatures.