Li adsorption on a Fullerene-Single wall carbon nanotube hybrid system: Density functional theory approach

Abstract

In this study, we investigate Li adsorption mechanisms on the C-60-SWCNT hybrid system using density functional theory. It is found that the Li adsorption energy of the C-60-SWCNT hybrid system is increased in comparison to that of the pure SWCNT. The Li adsorption energy ranges from -1.917 eV to -2.642 eV for the single-Li adsorbed system and from -2.351 eV to -2.636 eV for the double-Li adsorbed system. It is also found that the adsorption energy becomes similar at most positions throughout the structure. In addition, the Li adsorption energy of 31-Li system is calculated to be -1.863 eV, which is significantly lower than the Li-Li binding energy (-1.030 eV). These results infer that Li atoms will be adsorbed on the space 1) between C-60 and C-60; 2) between SWCNT and C-60; 3) the rest of the space (e. g. between SWCNTs), rather than form Li clusters. As more Li atoms are adsorbed onto the C-60-SWCNT hybrid system due to such improved Li adsorption capability, the metallic character of the system is enhanced, which is confirmed via the band structure and electronic density of states.