Preparation of layered <f>LiMnxCr1−xO2</f> solid solution by emulsion drying method as lithium intercalation compounds

Emulsion drying method has been successfully applied to the synthesis of <f>LiMnxCr1−xO2</f> <f>(0&les;x&les;0.6)</f> powders. <f>LiMnxCr1−xO2</f> 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 <f>LiMnxCr1−xO2</f> (space group; <f>R<ovl type="bar" STYLE="S">3</ovl>m</f>, <f>0&les;x&les;0.6</f>). 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 h <f>(g-oxide)−1</f> for <f>LiMn0.6Cr0.4O2</f>, and the material showed two charge potential stages; 3.5–3.9 and 3.9–4.3 V. [Copyright &y& Elsevier]