HYDROGEN SORPTION CAPACITY OF CRUMPLED GRAPHENE FLAKES WITH LITHIUM

10.25712/ASTU.1811-1416.2026.01.008

Abstract

The effect of the number of lithium atoms on the hydrogen sorption capacity of crumpled graphene flakes was studied using molecular dynamics. Structures containing different quantities of lithium atoms were considered:  0, 5.6 and 22.4 at.% Li, respectively. The structures were hydrogenated at 77 and 300 K. It was shown that doping the crumpled graphene flakes with lithium leads to an increase in their gravimetric density. The highest hydrogen sorption capacity (5.5 wt%) was obtained for flakes with 5.6 at.% Li at 77 K. Increasing the lithium content to 22.4 at. % leads to a decrease in sorption capacity due to the formation of lithium agglomerates on the graphene surface, which makes it difficult to adsorb hydrogen. When the temperature rises to 300 K, the hydrogen sorption capacity decreases to 1.5-2 wt.% in structures with 5.6 at.% Li. However, this sorption capacity is twice as high as that of a graphene flake without Li atoms.  The results of the study demonstrate the potential for using crumpled graphene flakes modified with lithium atoms to store and transport hydrogen, as they demonstrate an optimal hydrogen sorption capacity.