First-principles investigation of high reversible energy storage medium in Li-decorated net-Y

In this work, the net-Y monolayer decorated by Li was investigated for hydrogen storage through first-principles calculations. It was found that the added Li atom can be firmly anchored on the net-Y with an adsorption energy of −1.82 eV. Furthermore, the Li atom transferred its partial 2s electrons to the net-Y with a considerable electropositivity. These metallic sites can easily polarize the adsorbed hydrogen molecules, and the mutual electrostatic interactions are enhanced. Each suppercell of Li${}_8\circ$ net-Y can adsorb up to 24 H₂ molecules and the corresponding storage capacity can be as high as 9 wt%. This capacity significantly exceeds the target value of 5.5 wt% set by the U.S. Department of Energy (DOE). Moreover, the average adsorption energy of −0.268 eV/H₂ falls within the window of room temperature reversible hydrogen-storage energy range. This study highlights the metal decorated net-Y’s potential for hydrogen storage, inspiring further advancements along this direction.