Lithium ion secondary battery positive electrode material, lithium ion secondary battery positive electrode and lithium ion secondary battery that use same, and method for manufacturing lithium ion secondary battery positive electrode material

Provided are: a lithium ion secondary battery positive electrode material that has good rate characteristics and cycle characteristics while the density of a positive electrode active material is being increased; a lithium ion secondary battery positive electrode using the same; and a lithium ion secondary battery. The lithium ion secondary battery positive electrode material (1), which is represented by Li 1+x M1 1-x-y M2 y O 2 [-0.1 ≤ x ≤ 0.3, 0 ≤ y ≤ 0.1, M1 is Ni, Co, or Mn, M2 is Mg, Al, Ti, Zr, Mo, Nb, Fe, or B] and is an aggregate that includes secondary particles (50, 60) in which lithium metal composite oxide primary particles (10) having a layered structure are aggregated, is characterised in that: measured by laser diffraction/scattering particle size distribution, the secondary particles (50, 60) have a (D10) of 0.5-10 µm inclusive and a (D90) that exceeds 10 µm and is equal to or less than 50 µm; and the average porosity of the secondary particles having a particle diameter exceeding 10 µm and equal to or less than 50 µm is higher than the average porosity of the secondary particles having a particle diameter of 0.5-10 µm inclusive.