Lithium nickelate-based positive electrode active substance particles and process for producing the same, and non-aqueous electrolyte secondary battery

Abstract

The present invention provides lithium nickelate-based positive electrode active substance particles having a high energy density which are excellent in charge/discharge cycle characteristics when highly charged, and hardly suffer from generation of gases upon storage under high-temperature conditions, and a process for producing the positive electrode active substance particles, as well as a non-aqueous electrolyte secondary battery. The present invention relates to positive electrode active substance particles each comprising a core particle X comprising a lithium nickelate composite oxide having a layer structure which is represented by the formula: LiNiCoMOwherein M is at least one element selected from the group consisting of Mn, Al, B, Mg, Ti, Sn, Zn and Zr; a is a number of −0.1 to 0.2 (−0.1≤a≤0.2); b is a number of 0.05 to 0.5 (0.05≤b≤0.5); and c is a number of 0.01 to 0.4 (0.01≤c≤0.4); a coating compound Y comprising at least one element selected from the group consisting of Al, Mg, Zr, Ti and Si; and a coating compound Z comprising an Li element, in which a content of lithium hydroxide LiOH in the positive electrode active substance particles is not more than 0.40% by weight, a content of lithium carbonate LiCOin the positive electrode active substance particles is not more than 0.65% by weight, and a weight ratio of the content of lithium carbonate to the content of lithium hydroxide is not less than 1.