POSITIVE ELECTRODE AND NONAQUEOUS ELECTROLYTE SECONDARY BATTERY

[Object] Provided is a means capable of suppressing a decrease in capacity and improving output characteristics of a non-aqueous electrolyte secondary battery when the battery is used for a long period of time. [Solving Means] Disclosed is a positive electrode active substance for a non-aqueous electrolyte secondary battery, in which the true density/tap density of secondary particles of a lithium composite oxide containing nickel as the main component is within the range of 1.6 to 2.3, and in the secondary particles, the average porosity on the center side of the half (R/2 [µm]) of the particle radius (R) of D50 of the secondary particles is larger than the average porosity on the surface side.