SURFACE-MODIFIED CATHODE MATERIALS WITH AN AQUEOUS ALUMINA SOL AND A METHOD FOR PREPARING THE SAME

摘要

A method for preparing a positive electrode active material for a lithium secondary battery, a positive electrode active material prepared by the method, and a lithium secondary battery containing the positive electrode active material are provided to reduce the reaction time and to improve the simplicity of reaction by using water instead of an alcohol and by using a small amount of alumina. A method for preparing a positive electrode active material comprises the steps of hydrolyzing and polymerizing an aluminum alkoxide in an acidic aqueous solution to prepare an alumina sol; adding the alumina sol to a lithium transition metal oxide slurry prepared by using water as a solvent and stirring it to treat the surface of the lithium transition metal oxide with the alumina sol; and removing water and heat treating the dried power, wherein the acidic aqueous solution comprises 20-70 mol of distilled water and 1-4 mol of an organic acid.