Positive electrode active material for nonaqueous electrolyte secondary batteries comprising nickel-containing lithium transition metal oxide, nonaqueous electrolyte secondary battery comprising same, and method for producing positive electrode active material for nonaqueous electrolyte secondary batteries comprising nickel-containing lithium transition metal oxide

Abstract

A positive electrode active material for nonaqueous electrolyte secondary batteries includes a Ni-containing lithium transition metal oxide in the form of secondary particles formed by the aggregation of primary particles of the oxide, the proportion of Ni in the lithium transition metal oxide being not less than 80 mol % relative to the total number of moles of metal element(s) except Li, the average particle size of the primary particles being not less than 0.5 μm, the average particle size of the secondary particles being not less than 8 μm, the lithium transition metal oxide having a Ni disorder of not more than 3% and a crystallite size in the range of 100 to 200 nm according to X-ray diffractometry.