Cation ordering in the layered Li1+x(Ni0.425Mn0.425 Co0.15)1-xO2 materials (x=0 and 0.12)

The layered Li1+x(Ni0.425Mn0.425Co0.15)(1- x) O-2 (x=0 and 0.12) materials were prepared by a coprecipitation method. Their structure was investigated using the combination of X-ray and electron diffraction experiments. For both materials (x = 0 and 0.12), the electron diffraction patterns revealed an in-plane root 3a(hex) x root 3a(hex). superstructure in agreement with the ordering of the Li+, Ni2+, Ni3+, Mn4+ and Co3+ ions in the transition metal layers. The stoichiometry of these materials was not in agreement with an ideal ordering: the possible presence of point defects or of a domain microstructure was thus discussed. Electron diffraction also revealed that these ordered layers were slightly correlated along the C-hex axis for both materials. (c) 2007 Elsevier B.V. All rights reserved.