POSITIVE ELECTRODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY AND METHOD OF PREPARING THE SAME

The present invention provides a positive electrode active material which includes a lithium transition metal oxide in which nickel (Ni) is included in an amount of greater than 50 mol% based on a total number of moles of transition metals excluding lithium, wherein the positive electrode active material is in a form of single particles, a structure belonging to space group FD3-M and a structure belonging to space group Fm3m are formed in a region of 50 nm or less from a surface of the positive electrode active material in a center direction, and a generation rate of fine powder having an average particle diameter (D50) of 1 µm or less is in a range of 5% to 30% when the positive electrode active material is rolled at 650 kgf/cm2, a method of preparing the positive electrode active material, and a positive electrode for a lithium secondary battery and a lithium secondary battery which include the positive electrode active material.