Understanding Li-K edge structure and interband transitions in LixCoO2 by electron energy-loss spectroscopy

The authors clarified fine structures of Li-K edge of LiCoO2 reflecting core–hole effects, using monochromated transmission electron microscopy—electron energy-loss spectroscopy (TEM–EELS) and first-principles calculations. Variation of interband transitions into empty Co 3d states hybridized with O 2p states with decrease in x of LixCoO2 was also presented. A reduced peak of interband transitions at 3.2 eV in low-loss EELS spectrum with decrease in x was related to reduction in the original empty Co eg states for LiCoO2 and appearance of empty bands just below the eg band.