Positive electrode active material for lithium ion secondary battery, lithium ion secondary battery, and method for producing positive electrode active material for lithium ion secondary battery

Patent metadata

Field	Value
Publication number	US-11557764-B2
Application number	US-201816762625-A
Country	US
Kind code	B2
Filing date	Nov 9, 2018
Priority date	Nov 10, 2017
Publication date	Jan 17, 2023
Grant date	Jan 17, 2023

Abstract

A positive electrode active material for a lithium ion secondary battery, includes lithium-nickel composite oxide particles and a coating layer that covers at least a part of surfaces of the lithium-nickel composite oxide particles, in which components other than oxygen of the lithium-nickel composite oxide are represented by Li:Ni:Co:M=t:1−x−y:x:y (where, M is at least one element selected from the group consisting of Mg, Al, Ca, Si, Ti, V, Fe, Cu, Cr, Zn, Zr, Nb, Mo, or W, 0.95≤t≤1.20, 0<x≤0.22, and 0≤y≤0.15), the coating layer contains a Ti compound, and a Ti amount per 1 m2 surface area of the lithium-nickel composite oxide is 7.0 μmol or more and 60 μmol or less.

First claim

The invention claimed is:

1. A positive electrode active material for a lithium ion secondary battery, comprising lithium-nickel composite oxide particles and a coating layer that covers at least a part of surfaces of the lithium-nickel composite oxide particles, wherein
components other than oxygen of the lithium-nickel composite oxide are represented by Li:Ni:Co:M=t:1−x−y:x:y (where, M is at least one element selected from the group consisting of Mg, Al, Ca, Si, Ti, V, Fe, Cu, Cr, Zn, Zr, Nb, Mo, or W, 0.95≤t≤1.20, 0<x≤0.22, and 0≤y≤0.15), and
the coating layer contains a Ti compound, wherein a Ti amount per 1 m 2 surface area of the lithium-nickel composite oxide is 7.0 μmol or more and 60 μmol or less.

2. The positive electrode active material for a lithium ion secondary battery according to claim 1 , wherein a quotient of an amount ratio (Tis/Nis) of Ti to Ni that are present on a surface of the positive electrode active material for a lithium ion secondary battery and a ratio (Nib/(Nib+Cob+Mb)) of an amount of Ni to a sum of amounts of Ni, Co, and M in an entire positive electrode active material is 0.07 or more and 0.30 or less.

3. The positive electrode active material for a lithium ion secondary battery according to claim 1 , wherein a carbon content is 0.05% by mass or more and 0.40% by mass or less with respect to 100% by mass of the entire positive electrode active material for a lithium ion secondary battery.

4. The positive electrode active material for a lithium ion secondary battery according to claim 3 , wherein the carbon content is 0.08% by mass or less.

5. The positive electrode active material for a lithium ion secondary battery according to claim 1 , wherein a specific surface area of the lithium-nickel composite oxide is 0.1 m 2 /g or more and 1.0 m 2 /g or less.

6. The positive electrode active material for a lithium ion secondary battery according to claim 1 , wherein the lithium-nickel composite oxide is a layered rock-salt type compound particle having a crystal structure belonging to a space group R-3m.

7. A lithium ion secondary battery comprising at least a positive electrode containing the positive electrode active material for a lithium ion secondary battery according to claim 1 , a negative electrode, a separator, and a non-aqueous electrolyte solution.

8. A method for producing a positive electrode active material for a lithium ion secondary battery comprising lithium-nickel composite oxide particles and a coating layer that covers at least a part of surfaces of the lithium-nickel composite oxide particles, the method comprising at least:
a precursor crystallization process for preparing a nickel composite hydroxide that is a precursor of the lithium-nickel composite oxide by a crystallization reaction;
an oxidizing roasting process for oxidizing and roasting the nickel composite hydroxide obtained in the precursor crystallization process to obtain a nickel composite oxide;
a lithium-nickel composite oxide synthesis process for mixing the nickel composite oxide obtained in the oxidizing roasting process with a lithium compound to obtain a mixture and firing the mixture to obtain a lithium-nickel composite oxide; and
a coating process for forming the coating layer containing a Ti compound on at least a part of surfaces of particles of the lithium-nickel composite oxide obtained in the lithium-nickel composite oxide synthesis process.

9. The method for producing a positive electrode active material for a lithium ion secondary battery according to claim 8 , wherein
a Ti compound is added so that a Ti amount attributed to the Ti compound is 7.0 μmol or more and 60 μmol or less per 1 m 2 surface area of the lithium-nickel composite oxide in the coating process,
components other than oxygen of the lithium-nickel composite oxide obtained in the coating process are represented by Li:Ni:Co:M=t:1−x−y:x:y (where, M is at least one element selected from the group consisting of Mg, Al, Ca, Si, Ti, V, Fe, Cu, Cr, Zn, Zr, Nb, Mo, or W, 0.95≤t≤1.20, 0<x≤0.22, and 0≤y≤0.15), and
a quotient of an amount ratio (Tis/Nis) of Ti to Ni that are present on a surface of the positive electrode active material for a lithium ion secondary battery and a ratio (Nib/(Nib+Cob+Mb)) of an amount of Ni to a sum of amounts of Ni, Co, and M in an entire positive electrode active material is 0.07 or more and 0.30 or less.

10. The method for producing a positive electrode active material for a lithium ion secondary battery according to claim 8 , wherein firing is performed at a temperature of 700° C. or more and 800° C. or less in an oxygen-containing atmosphere in the lithium-nickel composite oxide synthesis process.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Okamoto Ryosuke

Classifications

• H01M4/485

  of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence) · CPC title

• H01M10/0525 Primary

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/525 Primary

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title