Effect of Cr doping on structure of LiMnO2

摘要

The monoclinic and orthorhombic ordered-rocksalt polymorphs of LiMnO2 are of interest as high-capacity cathode materials for rechargeable Li batteries. LiMnO2 and LiMn1-xCrxO2 were prepared by a high temperature solid-state route. In comparison with undoping Cr orthorhombic LiMnO2, monoclinic LiMnO2 was preserved with Cr doping. The volume of m-LiMnO2 decreasing with increasing Cr confirms that the length of bond around Cr ion decreases with Mn substituted by Cr ion. A phase transformation mechanism was proposed for understanding the structure relationship between the LiMnO2 and chromium-substituted LiMnO2 oxides.