Essential geometric and electronic properties in stage- n graphite alkali-metal-intercalation compounds

• Published in: RSC advances Vol. 10; no. 40; pp. 23573 - 23581
• Main Authors: Li, Wei-Bang, Lin, Shih-Yang, Tran, Ngoc Thanh Thuy, Lin, Ming-Fa, Lin, Kuang-I
• Format: Journal Article
• Language: English
• Published: England Royal Society of Chemistry 30.06.2020; The Royal Society of Chemistry
• Subjects: Alkali metal compounds; Atomic interactions; Charge density; Charge distribution; Chemistry; Conduction electrons; Energy bands; First principles; Graphite; Intercalation; Intercalation compounds; Interlayers; Lithium
• ISSN: 2046-2069; 2046-2069
• DOI: 10.1039/d0ra00639d

The rich and unique properties of the stage- graphite alkali-metal-intercalation compounds are fully investigated by first-principles calculations. According to the main features, the lithium and non-lithium (Na, K, Rb, Cs) systems are quite different from each other in stacking configurations, intercalant alkali-metal-atom concentrations, free conduction electron densities, atom-dominated and (carbon, alkali metal)-co-dominated energy bands, and interlayer charge density distributions. The close relations between the alkali-metal-doped metallic behaviors and the geometric symmetries are clarified through the interlayer atomic interactions. The stage-1 graphite alkali-metal-intercalation compounds possess the highest charge distribution for all stage- types; moreover, those of the lithium systems are greater than those of the non-lithium systems. The lithium systems also have the largest blue shift of the Fermi level among all alkali metal systems.