Nickel-cobalt composite hydroxide and method and device for producing same, cathode active material for non-aqueous electrolyte secondary battery and method for producing same, and non-aqueous electrolyte secondary battery

A method for producing a cathode active material for a non-aqueous electrolyte secondary battery, the method comprising the steps of:

• (a) forming, in a mixing process, a lithium mixture by mixing the nickel-cobalt composite hydroxide or a nickel-cobalt composite oxide,
• the nickel-cobalt composite hydroxide being produced by
• (i) obtaining, in a reaction process, a nickel-cobalt composite hydroxide by continuously supplying an aqueous solution including nickel and cobalt, an aqueous solution including an ammonium ion donor, and a caustic alkali aqueous solution to a reaction vessel and causing a reaction;
• (ii) continuously extracting, in a separation process, a slurry that includes the nickel-cobalt composite hydroxide from the reaction vessel, and separating the slurry into a large particle size portion and a small particle size portion by classification;
• and
• (iii) continuously returning, in a reflux process, the small particle size portion to the reaction vessel,
• wherein the nickel-cobalt composite hydroxide comprises
• a general formula of Ni1−x−yCoxMy(OH)2 (where, 0.05≤x≤0.50, 0≤y≤0.10, 0.05≤x+y≤0.50, and M is at least one kind of metal element selected from among Al, Mg, Mn, Ti, Fe, Cu, Zn and Ga,
• an average particle size of within a range from 10 μm to 30 μm, and
• (D50−D10)/D50≤0.30, and (D90−D50)/D50≤0.30 among D10, D50 and D90 of the nickel-cobalt composite hydroxide,
• the nickel-cobalt composite oxide being produced by
• (iv) roasting the nickel-cobalt composite hydroxide in an oxidizing atmosphere at a temperature of 300° C. to 700° C., and a lithium compound;
• and
• (v) performing calcination, in a calcination process, of the lithium mixture in an oxidizing atmosphere at a temperature of 600° C. to 850° C.