| CPC H01M 4/505 (2013.01) [C01G 53/42 (2013.01); C01G 53/44 (2013.01); H01M 4/525 (2013.01); H01M 10/0525 (2013.01); C01P 2002/74 (2013.01); C01P 2002/76 (2013.01); C01P 2004/03 (2013.01); C01P 2004/50 (2013.01); C01P 2004/61 (2013.01); C01P 2004/62 (2013.01); C01P 2006/12 (2013.01); H01M 2004/021 (2013.01); H01M 2004/028 (2013.01)] | 9 Claims |

|
1. A positive electrode active material for a lithium ion secondary battery, the positive electrode active material comprising a lithium-nickel composite oxide having a hexagonal layered structure and configured by particles including at least either single primary particles or secondary particles with a plurality of aggregated primary particles,
wherein metal elements constituting the lithium-nickel composite oxide include lithium (Li), nickel (Ni), and optionally at least one element M (M) selected from the group consisting of Co, Mn, Al, V, Mg, Mo, Ca, Cr, Zr, Ti, Nb, Na, K, W, Fe, Zn, B, Si, P, and Ta,
a mole number ratio of the metal elements is represented as Li:Ni:M=a:b:c (provided that, 0.95≤a≤1.10, 0.30≤b≤1.00, 0.00≤c≤0.70, and b+c=1),
the particles included in the positive electrode active material have a cross section having one or more crystal faces, and the one or more crystal faces in the particles have an average misorientation of 0.7° or less from a reference orientation of each of the one or more crystal faces, wherein the average misorientation is determined by an electron backscatter diffraction EBSD) method.
|