Hexagonal Boron Nitride (h‐BN) Sheets Decorated with OLi, ONa, and Li₂F Molecules for Enhanced Energy Storage

Abstract

First-principles electronic structure calculations were carried out on hexagonal boron nitride (h-BN) sheets functionalized with small molecules, such as OLi, ONa, and Li F, to study their hydrogen (H ) storage properties. We found that OLi and ONa strongly adsorb on h-BN sheets with reasonably large inter-adsorbent separations, which is desirable for H storage. Ab initio molecular dynamics (MD) simulations further confirmed the structural stability of OLi-BN and ONa-BN systems at 400 K. On the other hand, Li F molecules form clusters over the surface of h-BN at higher temperatures. We performed a Bader charge investigation to explore the nature of binding between the functionalized molecules and h-BN sheets. The density of states (DOS) revealed that functionalized h-BN sheets become metallic with two-sided coverage of each type of molecules. Hydrogenation of OLi-BN and ONa-BN revealed that the functionalized systems adsorb multiple H molecules around the Li and Na atoms, with H adsorption energies ranging from 0.20 to 0.28 eV, which is desirable for an efficient H storage material.

Boron Nitride for Hydrogen Storage

“…Alternatively, sodium and other alkali derivatives (e.g., OLi, ONa, Li 2 F) were suggested as possible sorption sites for BN . Another method would be to modify a BN structure at a molecular level with such alkali elements.…”

“…[27] Alternatively, sodium and other alkali derivatives (e.g.,O Li, ONa, Li 2 F) were suggested as possible sorption sites for BN. [66,67] Another method would be to modify aB Ns tructure at am olecular level with such alkali elements. This would lead to more heterosites as well as defects in the structure, then leading to increasedH 2 uptake.…”

Enriching the hydrogen storage capacity of carbon nanotube doped with polylithiated molecules

“…However, the scope of CNT functionalized with PLMs for H 2 storage application is yet to be explored. Our group has extensively explored the promise of H 2 storage properties of various 2D materials functionalized with different polylithiated species [30][31][32][33] However the focus has been on 2D materials and 1D nanotubes has not be considered.…”

High‐capacity hydrogen storage on Li‐decorated B16N16

“…[17][18][19] Therefore, alkali and alkaline metal atoms are better choices for decoration because of their lightweight and small cohesive energies, which will prevent the clustering of the metal atoms. [20][21][22][23][24][25][26][27][28][29][30] As the lightest metal, lithium atoms were selected for decoration on BN nanosystems in many studies. In the work of Venkataramanan, the Li 6 B 36 N 36 cluster held 18 H 2 and the adsorption energy of each H 2 was 0.19 eV.…”