Li atom adsorption on graphene with various defects for large-capacity Li ion batteries: First-principles calculations

Abstract

We investigated the fundamental properties of the interaction between a Li atom and a graphene surface with various defect structures by first-principles electronic state calculations to improve the capacity and charge rate of a graphitic anode for Li ion battery applications. The adsorption energy tends to decrease as the number of deficit carbon atoms at a neighboring defect increases even for adsorption at a hexagonal ring (HR) away from defects, although the interaction between a Li adatom and an HR is similar independent of the defect structure. The reason for the change in adsorption energy is the electronic charge transfer from the Li 2s-like state to the defect-induced state near the Fermi level. We also found that a Li atom diffuses through a V6 defect without a diffusion barrier practically.