POSITIVE ACTIVE MATERIAL FOR RECHARGEABLE LITHIUM BATTERY, PREPARING METHOD THEREOF, AND RECHARGEABLE LITHIUM BATTERY INCLUDING THE SAME

• Main Authors: SHIN, Dongwook, KIM, Hyunjeong, SONG, Jayhyok, KANG, Gwiwoon, HONG, Soonkie
• Format: Patent
• Language: English; French; German
• Published: 22.02.2023
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

Disclosed is a positive electrode active material for a rechargeable lithium battery comprising a first and a second active material both comprising a lithium nickel based composite oxide having a nickel content of greater than or equal to 90 mol% based on the total amount of metals excluding lithium and are made of secondary particles on which a cobalt coating layer is present. The first positive electrode active material exhibits a particle diameter of 10 to 25 microns while the second positive electrode active material exhibits a particle diameter of 1 to 9 microns. Also disclosed are a method of preparing a positive active material for a rechargeable lithium battery that includes preparing a first aqueous solution that includes a cobalt salt a composite particles including a lithium nickel-based composite oxide and in the form of secondary particles in which a plurality of primary particles are aggregated, and has a pH of 6 to 8, adding an alkali material into the first aqueous solution to obtain a second aqueous solution, obtaining a pre-positive active material including the composite particles and a cobalt coating layer formed on the surface thereof in the second aqueous solution, heat-treating the pre-positive active material to obtain a final positive active material, a positive active material for a rechargeable lithium battery, and a rechargeable lithium battery.