A First-Principles Study of Lithium Adsorption on a Graphene-Fullerene Nanohybrid System

Abstract

The mechanism of Li adsorption on a graphene-fullerene (graphene-C-60) hybrid system has been investigated using density functional theory (DFT). The adsorption energy for Li atoms on the graphene-C-60 hybrid system (-2.285 eV) is found to be higher than that on bare graphene (-1.375 eV), indicating that the Li adsorption on the former system is more stable than on the latter. This is attributed to the high affinity of Li atoms to C-60 and the charge redistribution that occurs after graphene is mixed with C-60. The electronic properties of the graphene-C-60 system such as band structure, density of states, and charge distribution have been characterized as a function of the number of Li atoms adsorbed in comparison to those of the pure graphene and C-60. Li adsorption is found to preferentially occur on the C-60 side due to the high adsorption energy of Li on C-60, which imparts a metallic character to the C-60 in the graphene-C-60 hybrid system.