Positive electrode active material for non-aqueous electrolyte secondary batteries, production method therefor, and non-aqueous electrolyte secondary batteries using said positive electrode active material

A production method for a positive electrode active material for non-aqueous electrolyte secondary batteries containing a lithium nickel composite oxide,

• the method comprising processes of (A) to (D) described below in order of the processes of (A) to (D):
• (A) a process of mixing a nickel compound containing nickel, cobalt, and at least one type selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr, and Mo, and a lithium compound, and then, of firing the compounds in a temperature range of 720° C. to 770° C. in an oxidizing atmosphere, and thus, of preparing a fired powder of a lithium nickel composite oxide that is represented by at least General Formula:
• LizNi1-x-yCoxMyO2 (here, 0.98≤z≤1.05, 0<x≤0.20, 0<y≤0.10, x+y≤0.20, and M is at least one type of element selected from Mg, Al, Ca, Ti, V, Cr, Mn, Nb, Zr, and Mo) and contains primary particles and secondary particles configured by aggregating the primary particles;
• (B) a process of forming a slurry such that an amount of the fired powder of the lithium nickel composite oxide is 1000 g to 2000 g with respect to 1 L of water, and of obtaining a cleaned cake by performing a water washing treatment with respect to the fired powder of the lithium nickel composite oxide that is prepared in the process of (A);
• (C) a process of adding an aluminum compound and a tungsten compound to the cleaned cake of the process of (B), and of mixing the compounds and the cake, wherein an amount of Al contained in the aluminum compound is 0.01 atom % to 0.50 atom % with respect to the total number of atoms of Ni, Co, and M contained in the lithium nickel composite oxide and an amount of W contained in the tungsten compound is 0.05 atom % to 0.30 atom % with respect to the total number of atoms of Ni, Co, and M contained in the lithium nickel composite oxide;
• and
• (D) a process of performing a thermal treatment with respect to the mixture of the fired powder of the lithium nickel composite oxide, the aluminum compound, and the tungsten compound that is prepared in the process of (C), at 100° C. to 600° C. in an oxygen atmosphere or a vacuum atmosphere to form and of forming a LiAl compound and a LiW compound on surfaces of the primary particles of the fired powder of the lithium nickel composite oxide, the LiAl and LiW compounds being in particulate form and having a particle size of 1 nm to 100 nm.