VIBRATIONAL-SPECTRA OF SUPERDENSE LITHIUM GRAPHITE-INTERCALATION COMPOUNDS

IR investigations of lithium graphite intercalation compounds with dif ferent lithium in-plane density (LiC6, LiC4, LiC2) were carried out. T he spectra interpretation was done on the basis of normal coordinate a nalysis for model structures. LiC2 and LiC4 spectra exhibit the bands corresponding to a complex skeleton stretching in Li-7 or LiC6 cluster s including equilateral triangles of metal atoms at short distances wh ich shows that covalence exists between Li atoms in the intercalated l ayer and that LiCx decomposition proceeds keeping these clusters in Li Cx structure for x < 4 at least. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.