CATHODE ACTIVE MATERIAL AND PREPARATION METHOD, LITHIUM SECONDARY BATTERY AND PREPARATION METHOD

摘要

PURPOSE: A positive electrode active material is provided to improve cycleability at a room temperature and high temperature while the capacity is not degraded by suppressing the elution of Mn ions by coating lithium oxides containing nickel and manganese on the surface of LiMn2O4. CONSTITUTION: A positive electrode active material enables absorption and discharge of lithium ions and is such that lithium oxides containing nickel and manganese are coated on the surface of LiMn2O4. The lithium oxide is LiNi_xMn_(1-x)O_2. A method for preparing the positive electrode active material comprises the steps of: (i) preparing a sol of lithium oxides containing nickel and manganese; and coating the sol of lithium oxides on the surface of LiMn2O4; and additionally heat-treating LiMn2O4 in which the lithium oxide is coated.