Cathode active material for lithium ion secondary battery and method for producing same

Patent metadata

Field	Value
Publication number	US-12444740-B2
Application number	US-201917043844-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 2, 2018
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

The cathode active material for a lithium ion secondary battery is produced from spherical particles made of lithium nickel cobalt composite oxide represented by general formula: Li z Ni 1−x−y Co x M y O 2 (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) and having a volume average particle diameter MV in a range of preferably 8 to 30 μm, wherein an area ratio of a lithium compound unevenly distributed on surfaces of the particles in a SEM image is 5% or less. The spherical particles preferably have a crystallite diameter in a range of 50 to 200 Å as determined from a full width at half maximum, FWHM of diffraction peak of (003) plane obtained by X ray diffraction by using Sherrer formula.

First claim

The invention claimed is:

1. Spherical particles made of a lithium nickel cobalt composite oxide represented by a general formula: Li z Ni 1-x-y Co x M y O 2 ,
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.

2. The spherical particles made of a lithium nickel cobalt composite oxide according to claim 1 , which are a precursor.

3. The spherical particles made of a lithium nickel cobalt composite oxide according to claim 1 , whose volume average particle diameter MV is in a range of 8 to 30 μm.

4. The spherical particles made of a lithium nickel cobalt composite oxide according to claim 2 , whose volume average particle diameter MV is in a range of 8 to 30 μm.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Kondo Kentaro
• Komukai Tetsufumi

Classifications

• C01P2002/60

  Compounds characterised by their crystallite size · CPC title

• C01P2004/03

  obtained by SEM · CPC title

• C01P2004/32

  Spheres · CPC title

• C01G53/82

  Compounds containing nickel, with or without oxygen or hydrogen, and containing two or more other elements · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title