A NOVEL TYPE OF REACTION IN THE CHEMISTRY OF GRAPHITE-INTERCALATION COMPOUNDS - THE PREPARATION OF ALKALI-METAL GRAPHITE-INTERCALATION COMPOUNDS BY ION-EXCHANGE REACTIONS

The treatment of KC8 or KC24 with a solution of LiCl or LiClO4 in tetr ahydrofuran (THF) results in the exchange of K+ ions in the GIC for Li + ions. Depending on the ratio salt/GIC, ternary Li-THF-GICs with eith er d(i) = 12.5 Angstrom or d(i) = 7.16 Angstrom have been obtained. An alogous reactions between KC8 or KC24 and solutions of NaI in THF lead to the formation of Na-THF-GIC with d(i) = 11.2 Angstrom. The same GI C was prepared by reactions of LiC6 or LiC12 and solutions of NaI in T HF. Li-THF-GIC can be also obtained by reacting Na(NH3)(x)C-14 with so lutions of LiCl in THF. A model to explain the mechanism of ion exchan ge of intercalated alkali metal ions with ions in THF solution is prop osed. (C) 1997 Elsevier Science Ltd.