RAMAN-SPECTRA OF LICO1-YNIYO2

Raman spectra of lithium-cobalt-nickel oxide, LiCo1-yNi2O2 (0 less tha n or equal to y less than or equal to 1), which is a promising materia l for the cathodes of secondary lithium batteries, were studied. By fa ctor group analysis, Raman-active modes of LiCoO2 (y = 0) were assigne d as A1g + Eg, and their atomic displacements were speculated. The the oretical results were confirmed by the observed two strong Raman band of LiCoO2 (y = 0). With replacing Co with Ni, the intensities of both bands decreased drastically, and the peak wavenumbers of the lower and upper bands were up- and down-shifted, respectively.