Abstract: The present invention relates to a lithium metal composite oxide represented by the composition formula (I), the lithium metal composite oxide satisfies requirements (1) to (3): (1) a ratio (I1/I2) of an integral intensity I1 of a diffraction peak in a range of 2?= 36.7 ± 1° with respect to an integral intensity I2 of a diffraction peak in a range of 2?= 64.9 ± 1° in a powder X-ray diffraction measurement for the lithium metal composite oxide using Cu—K? ray is 2.0 or more; (2) a BET specific surface area is 0.7 m2/g or less; and (3) a 10% cumulative volume particle size D10 is 5 µm or more.

Abstract: A lithium metal composite oxide powder having a layered structure, containing at least Li, Ni, an element X, and an element M, in which the element X is one or more elements selected from the group consisting of Co, Mn, Fe, Cu, Ti, Mg, Al, W, Mo, Nb, Zn, Sn, Zr, Ga, and V, the element M is one or more elements selected from the group consisting of B, Si, S, and P, M/(Ni+X) that is a content ratio of the element M to a total amount of Ni and the element X that are contained in the lithium metal composite oxide powder is 0.01 mol % or more and 5 mol % or less, Ni/(Ni+X) that is a content ratio of Ni to the total amount of Ni and the element X that are contained in the lithium metal composite oxide powder satisfies 0.40 or more in terms of a mole ratio, and a ratio of the element M eluted into N-methyl-2-pyrrolidone measured under specific measurement conditions is 0.09 or less.