First-Principles Study of Lithium Adsorption and Diffusion on Graphene with Point Defects

• Published in: Journal of physical chemistry. C Vol. 116; no. 41; pp. 21780 - 21787
• Main Authors: Zhou, Liu-Jiang, Hou, Z. F, Wu, Li-Ming
• Format: Journal Article
• Language: English
• Published: Columbus, OH American Chemical Society 18.10.2012
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Electron states and collective excitations in thin films, multilayers, quantum wells, mesoscopic and nanoscale systems; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Physics; Thin films and multilayers; Point defects; Vacancies; Surface electron state; Surface diffusion; Electronic density of states; Charge density; Adsorption; Graphene; Density functional method; Adatoms; Divacancy; Charge transfer; Stone Wales defect
• DOI: 10.1021/jp304861d
• ISSN: 1932-7447

To understand the effect of point defects on the Li adsorption on graphene, we have studied the adsorption and diffusion of lithium on graphene with divacancy and Stone–Wales defect using the first-principles calculations. Our results show that in the presence of divacancy Li adatom energetically prefers the hollow site above the center of an octagonal ring rather than the top sites of carbon atoms next to vacancy site. In the case of Stone–Wales defect, Li atom is energetically favorable to be adsorbed on the top site of carbon atom in a pentagonal ring shared with two hexagonal rings, and such adsorption results in a bucking of graphene sheet. For divacancy and Stone–Wales defects in graphene, their interactions with a Li adatom are attractive, suggesting that the presence of point defects would enhance the Li adsorption on graphene. The difference charge density and the Bader charge analysis both show that there is a significant charge transfer from Li adatom to it nearest neighbor carbon atoms.