| 摘要 |
The invention provides a cathode active material for use in a rechargeable battery, comprising a coated lithium nickel oxide powder or a coated lithium nickel manganese oxide powder, the powder being composed of primary particles provided with a glassy lithium silicate surface coating. A method for preparing the cathode active material comprises the steps of:
providing a lithium transition metal based oxide powder,providing an alkali mineral compound comprising a Li2−xSiO3−0.5x compound, wherein 0<x<2,mixing the lithium transition metal based oxide powder and the alkali mineral compound to form a powder-mineral compound mixture, andheat treating the mixture at a temperature T whereby lithium is extracted from the surface of the metal based oxide powder to react with the alkali mineral compound, and a glassy surface coating is formed comprising a Li2−x″SiO3−0.5x″ compound, wherein x<x″<2. |
