Structure of fluorine-graphite intercalation compounds

✍ Scribed by T Nakajima; M Molinier; M Motoyama

• Publisher: Elsevier Science
• Year: 1991
• Tongue: English
• Weight: 836 KB
• Volume: 29
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(91)90212-2

✦ Synopsis

Fluorine-graphite intercalation compounds have been prepared from HOPG and natural graphite powder in the presence of a fluoride such as AgF, WF,, or SbF, at room temperature. The C,F samples obtained were quasi stage 1, 2, and 3 compounds with compositions of Cz ,F-CU hF. The stage 1 hases in the admixtures of stages 1 and 2 prepared from HOPG show large I, values of 10.5 to 11.9 1 X-ray powder diffraction indicates the existence of an in-plane superlattice with a" = 2a, in the stage 3 and 2 compounds, but no superlattice at quasi stage 1. Electron diffraction for the same samples also reveals an in-plane superlattice at stages 3 and 2. Based on these results, c-axis and inplane structure models have been proposed for sage 1 through 3, C,F. The phase with a large I, value is a bi-intercalation phase in which two kinds of ionically and semi-ionically bonded fluorines with different sizes are inserted between every other carbon layer. For the in-plane structures, the proposed models are that stage 3 and 2 compounds consist of C,.F and C,,,F with a,, = 2a,, which lead to the C>,F structure and/or some disordered one with a,, = a, at stage 1.