The electrochemical preparation and properties of ionic alkali metal-and NR4-graphite intercalation compounds in organic electrolytes

✍ Scribed by J.O. Besenhard

• Publisher: Elsevier Science
• Year: 1976
• Tongue: English
• Weight: 650 KB
• Volume: 14
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(76)90119-6

✦ Synopsis

The preparation of graphite-alkali metal-solvent or graphite-N&-solvent ternary intercalation compounds by electrochemical reduction of graphite is described. The reduction occurs stagewise and the complete formation of a defined stage can be recognized by a striking change in the potential of the graphite electrode. Under certain conditions the stoichiometry of intercalation compounds (e.g. C,K(DMSO), C,,K(DMSO), C,,Li(DME) can be calculated from the coulombs consumed by a weighed graphite electrode until a step in potential occurs. The electrochemical intercalation of alkali metals into graphite is reversible. It may be reversed with a coulombic efficiency up to practically lOO%, e.g. for C.K(DMSO). A considerable co-intercalation of alkali metal salts from the electrolyte was not observed. From a preparative point of view, a great advantage over the direct chemical reduction of graphite is that a desired degree of intercalation can be specifically prepared. A coulometric determination of the intercalated cations is possible by way of an electrochemical reoxidation. Potential measurements of electrochemically prepared intercalation compounds with a well-defined degree of intercalation represent a simple method for investigating the thermodynamics of these reactions. Furthermore, by means of dynamic electrochemical methods, such as cyclic voltammetry, information about the kinetics of intercalation reactions is obtainable.