A first-principles study on the adsorption stability of lithium on graphene surfaces

This study delves into the adsorption stability of lithium (Li) on graphene surfaces based on first-principles calculations. The findings reveal that the most stable adsorption site for Li atoms on graphene is the center of the C₆ ring (designated as the H site), with an adsorption energy of −2.80 eV. As the adsorption density of Li increases, the adsorption energy gradually shifts towards positive values, indicating a reduction in adsorption stability. Concurrently, the interlayer spacing of graphene exerts a notable influence on Li adsorption, with optimal stability observed when the spacing ranges from 0.43 to 0.44 nm. Moreover, the migration energy barrier for Li to transition from one H site to another is relatively high (0.25 eV), further confirming the exceptional structural stability of Li on the graphene surface. This research elucidates the lithium storage mechanism of graphene anode materials at the atomic level, offering theoretical insights for the electrode design of high-performance lithium-ion batteries.