Density functional theory calculations are used to explore the Li storage capacity of Ngm endohedral C60 fullerenes (Ng=He, Ne, Ar, Kr, Xe; m=1,2). Formation energies of Ng endohedral fullerenes are negative, ranging from -2.65 to -13.11 kcal/mol (at the PBE/DNP level). The incorporation of Ng and Ng2 moieties into C60 enhances the adsorption energy of Li. The maximum adsorption energy of the Li atom on Xe2 encapsulated C60 is about -45 kcal/mol, which is 7% larger than that of on pure C60. The presence of Ng atoms lowers the energy barrier for Li migration to neighboring pentagon or hexagon rings.
