Lithium on CH Divacancy Self-Healed Graphane: A First-Principles Study

Abstract

The possibility of using graphane monolayer crystals as an electrode material is becoming popular. Graphane is stable at room temperature and has a large surface area, but its chemical inertness hinders its direct interactions with Li ions. In this study, we performed density functional theory calculations to study the energetic stability and structural and electronic properties of Li on graphane with various CH divacancy configurations (v12, v13, and v14). The results show that the adsorption of the Li atom reduces the formation energy of the CH divacancy configurations. The Li-v12 is most stable with the highest binding energy of 3.25 eV/Li and relaxes to in-plane with other C atoms. Altering the Li charge state to have Li−1-v12 or Li+1-v12 affects the energetic stability and electronic characters of Li-v12. The Li−1-v12 (Li+1-v12) slightly (greatly) reduces the binding force between the Li and v12 configuration, and furthermore it improves (deteriorates) the conductivity of the structure. Further investigation of graphane with vacancies is encouraged due to these intriguing observations, as it holds promise for potential utilization as an electrode material.

Keywords

• graphane
• divacancy
• lithiation
• density functional theory
• charge doping
• conductivity