Density Functional Theory Study on Li-Decorated B12N12 Cage for Hydrogen Storage Behavior

Hydrogen storage behavior in a Li-decorated B12N12 cage is investigated using first-principles calculations based on density functional theory (DFT). In the optimized adsorption structure, three Li atoms are adsorbed above the N atom of the B12N12 cage (Top-N site). Each Li atom is adsorbed on the bridge site of B-N between the four- and six-membered rings. In addition, each Li atom in the B12N12 cage adsorbs three H-2 molecules, and two H-2 molecules are adsorbed outside the B12N12 cage, with an average H-2 adsorption energy of -0.14 eV. Inside the B12N12 cage, the adsorbed hydrogen remains in the molecular form. Our work shows that the maximum hydrogen storage capacity of Li-decorated B12N12 cage is 9.1% (w).