Enhanced physical hydrogen storage in g-C10N3 monolayer with lithium decoration: A first-principles study

Abstract

The pure ▪ monolayer has low hydrogen gravimetric storage capacity due to the fact that their van der Waals interactions are not strong enough. In this study, we proposed a novel composite, Li∘▪ , for physical hydrogen storage based on first-principles calculations. Lithium (Li) atoms can securely anchor to ▪ with a bonding energy of -3.37 eV, exhibiting excellent thermal stability. Li∘▪ can hold 7 H2 molecules per unit cell around room temperature, achieving an 8.0 wt% gravimetric storage capacity with average adsorption energies ranging from -0.277 eV/H2 to -0.208 eV/H2. Desorption temperatures range from 269 K to 358 K, indicating good kinetic properties. Relative energy studies confirm Li∘▪ as a promising energy storage material under moderate pressure (>6 bar) and room temperature conditions. The adsorption mechanism involves synergistic electrostatic and van der Waals interactions. We hope that more material-based hydrogen storage techniques will be developed in this direction.