Positive electrode active material for non-aqueous electrolyte secondary battery and method for manufacturing the same, positive electrode mixed material paste for non-aqueous electrolyte secondary battery, and non-aqueous electrolyte secondary battery

A method for manufacturing a positive electrode active material for a non-aqueous electrolyte secondary battery, the method comprising:

• mixing fired powder comprising a lithium-metal composite oxide having a crystal structure of a layered structure, a boron compound not including lithium but being capable of reacting with lithium, and water;
• and
• drying the resultant mixture obtained by the mixing to obtain a positive electrode active material, wherein
• the fired powder is represented by a general formula LisNi1−x−y−zCoxMnyMzO2+α (where 0≤x≤0.35, 0≤y≤0.35, 0≤z≤0.10, 0.95<s<1.30, and 0≤α≤0.2, and M represents at least one element selected from V, Mg, Mo, Nb, Ti, W, and Al) and contains a secondary particle formed by agglomeration of primary particles, and
• the boron compound is mixed such that the amount of an eluted lithium hydroxide measured with a neutralization titration method upon dispersing the positive electrode active material in water is at least 0.003% by mass and up to 0.5% by mass relative to the total of the positive electrode active material.