Infrared and Raman spectroscopy of nanostructured LT-LiCoO2 cathodes for Li-ion rechargeable batteries

Nano-engineered electrodes, such as porous LiCoO2, exhibit improved electrochemical performance compared to the non-porous LiCoO2 analogue. Structural studies of the pore walls composing the nanostructured LiCoO2 materials have focused on long-range (diffraction) methods. However, the powder diffraction patterns of the low-temperature (LT) and high-temperature (HT) phases of nonporous LiCoO2 are very similar and distinguishing the two phases can be challenging. In this work, infrared and Raman spectroscopy are used to unambiguously assign the LiCoO2 crystalline domains present in two porous compounds (nanowire LiCoO2 and mesoporous LiCoO2) as LT-LiCoO2, Moreover, the appearance of new bands in the infrared spectrum of LiCoO2 nanowires might signal the presence of disordered LiCoO2 domains that are XRD silent. (C) 2009 Elsevier B.V. All rights reserved.