Lattice vibrations of materials for lithium rechargeable batteries V.: Local structure of Li0.3MnO2

We report the structural properties of Li0.3MnO2 positive electrode materials for secondary lithium batteries. The crystal structure examined by X-ray diffraction corresponds to a new MnO2 with an ordered alternation of (1 x 2) and (1 x 1) channels of the gamma-MnO2 phase. The vibrational properties studied by Raman scattering (RS) and Fourier transform infrared (FTIR) spectroscopy as local probes show that lithium ions are located in octahedral sites in the (1 x 2) channels. Significant changes are seen in the MnO6 octahedral arrangement from sample to sample by examining the spectra in high-frequency region compared with their parents that are pyrolusite and ramsdellite manganese dioxides. The cycling behavior of the Li0.3MnO2 electrode exhibits a practical material utilization capacity of 155 mA h g(-1) over 60 cycles. (C) 2003 Elsevier Science B.V. All rights reserved.