Order-Disorder Phenomena in Graphite Intercalation Compounds and Reduction Reactions in Alkali Metal-Intercalated Compounds of Graphite

Abstract

Graphite was oxidized to graphite hydrogen sulfate with ammonium peroxodisulfate. With increasing oxidation time significant differences were found for the interlayer spacing, the ratio of intercalated anions and free acid molecules, and for the density of the stage 1 compound. There was a minimum of the density of the intercalated layers after ca. 15 minutes. — Perfluoro-n-butanesulfonic acid was intercalated electrochemically by galvanostatic and cyclovoltammetric methods. In this case two phases with different thickness of the intercalated layers were observed for the stage 2 and stage 1 compounds. At relatively low charge densities for a given stage the spacing is lower by ca. 320 pm than in the fully oxidized compound. There was evidence for a disordered sequence of thick and thin interlayers in the transition. — Potassium graphite, KC₈, was reacted with solutions in THF of ZnCl₂ FeCl₃, MnCl₂ · 4 H₂O, COCl₂ · 6 H₂O and CUCl₂ · 2 H₂O. Literature reports that transition-metal-intercalated graphite is formed could not be confirmed with the possible exception of ZnCl₂ where chemical composition and line scans in energy-dispersive analysis gave some indication of intercalation.