Preparation of layered LiMnxCr1-xO2 solid solution by emulsion drying method as lithium intercalation compounds

Emulsion drying method has been successfully applied to the synthesis of LiMnxCr1-xO2 (0less than or equal toxless than or equal to0.6) powders. LiMnxCr1-xO2 powders were formed by a direct calcination of the-emulsion-dried precursors. Rietveld refinement of the X-ray diffraction patterns and the gradual decrease of lattice parameters with increasing the amount of Mn substitution demonstrated a wide range of solid solutions LiMnxCr1-xO2 (space group; R (3) over barm, 0less than or equal toxless than or equal to0.6). The prepared crystallite size was less than 300 nm in diameter. The charge and discharge curves greatly depended on the Mn substitution amount. The reversibility between charge and discharge capacities as a Li-ion battery cathode was enhanced by higher level Mn substitution. The initial discharge capacity was about 175 mA It (g-oxide)(-1) for LiMn0.6Cr0.4O2, and the material showed two charged potential stages; 3.5-3.9 and 3.9-4.3 V. (C) 2002 Elsevier Science B.V. All rights reserved.