US 12,444,740 B2
Cathode active material for lithium ion secondary battery and method for producing same
Kentaro Kondo, Niihama (JP); and Tetsufumi Komukai, Tokyo (JP)
Assigned to SUMITOMO METAL MINING CO., LTD., Tokyo (JP)
Appl. No. 17/043,844
Filed by SUMITOMO METAL MINING CO., LTD., Tokyo (JP)
PCT Filed Apr. 1, 2019, PCT No. PCT/JP2019/014562
§ 371(c)(1), (2) Date Oct. 29, 2020,
PCT Pub. No. WO2019/194150, PCT Pub. Date Oct. 10, 2019.
Claims priority of application No. 2018-070846 (JP), filed on Apr. 2, 2018.
Prior Publication US 2021/0111404 A1, Apr. 15, 2021
Int. Cl. H01M 4/525 (2010.01); C01G 53/82 (2025.01); H01M 4/485 (2010.01); H01M 4/505 (2010.01); H01M 10/0525 (2010.01); H01M 4/02 (2006.01)
CPC H01M 4/525 (2013.01) [C01G 53/82 (2025.01); H01M 4/485 (2013.01); H01M 4/505 (2013.01); H01M 10/0525 (2013.01); C01P 2002/60 (2013.01); C01P 2004/03 (2013.01); C01P 2004/32 (2013.01); H01M 2004/021 (2013.01)] 4 Claims
OG exemplary drawing
 
1. Spherical particles made of a lithium nickel cobalt composite oxide represented by a general formula: LizNi1-x-yCoxMyO2,
wherein M is at least one element selected from among Mn, V, Mg, W, Mo, Nb, Ti, and Al and x, y, and z satisfy 0<x≤0.35, 0≤y≤0.35, and 0.97≤z≤1.20, respectively,
wherein the spherical particles are produced by preliminary firing having a firing temperature within a range of 550° C. or higher and 600° C. or lower in an oxidizing atmosphere having an oxygen concentration of 80 vol % or more,
wherein an area ratio of lithium hydroxide and/or lithium carbonate unevenly distributed on surfaces of the particles as compared to the area of the particles as a whole in a SEM image is 5% or less, and
wherein a crystallite diameter of the particles determined from a full width at half maximum, FWHM of diffraction peak of (003) plane obtained by X ray diffraction by using Sherrer formula is in a range of 50 to 200 Å.