Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing the same, and nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-10784500-B2
Application number	US-201715582968-A
Country	US
Kind code	B2
Filing date	May 1, 2017
Priority date	May 1, 2017
Publication date	Sep 22, 2020
Grant date	Sep 22, 2020

Abstract

In one aspect, a method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery, includes mixing first lithium nickel composite oxide particles containing lithium tungstate and second lithium nickel composite oxide particles not containing lithium tungstate. The first lithium nickel composite oxide particles have a composition represented by Li z1 Ni 1-x1-y1 Co x1 M 1 y1 O 2 , and include a core material containing secondary particles each corresponding to an aggregation of a plurality of primary particles, and the lithium tungstate existing on at least a part of a surface of the primary particles on a surface of and inside the first lithium nickel composite oxide particles. The second lithium nickel composite oxide particles have a composition represented by Li z2 Ni 1-x2-y2 Co x2 M 2 y2 O 2 , and include secondary particles each corresponding to an aggregation of a plurality of primary particles.

First claim

The invention claimed is:

1. A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising first lithium nickel composite oxide particles containing lithium tungstate and second lithium nickel composite oxide particles not containing lithium tungstate, wherein
the first lithium nickel composite oxide particles have a composition represented by Li z1 Ni 1-x1-y1 Co x1 M 1 y1 O 2 where 0≤x1≤0.35, 0≤y1≤0.35, 0.95≤z1≤1.15, and M 1 is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al, and include a core material containing secondary particles each corresponding to an aggregation of a plurality of primary particles, and the lithium tungstate existing on at least a part of a surface of the primary particles on a surface of and inside the first lithium nickel composite oxide particles,
the second lithium nickel composite oxide particles have a composition represented by Li z2 Ni 1-x2-y2 Co x2 M 2 y2 O 2 where 0≤x2≤0.35, 0≤y2≤0.35, 0.95≤z2≤1.15, and M 2 is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al, and include secondary particles each corresponding to an aggregation of a plurality of primary particles, and
an amount of the first lithium nickel composite oxide particles contained in the positive electrode active material is 10% by mass or more and 70% by mass or less relative to the total amount of the positive electrode active material.

2. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the amount of lithium contained in a lithium compound other than lithium tungstate existing on a surface of the primary particles on a surface of and inside both the first lithium nickel composite oxide particles and the second lithium nickel composite oxide particles is 0.05% by mass or less relative to the total amount of the positive electrode active material.

3. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode active material contains the first lithium nickel composite oxide particles by 10% by mass or more and 60% by mass or less relative to the total amount of the positive electrode active material.

4. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium tungstate contains tungsten by 0.03 at % or more and 2.5 at % or less relative to the total number of atoms of Ni, Co, and M contained in the positive electrode active material.

5. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium tungstate contains tungsten by 0.05 at % or more and 3.0 at % or less relative to the total number of atoms of Ni, Co, and M contained in the first lithium nickel composite oxide particles.

6. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium tungstate exists as a microparticle with a particle diameter of 1 nm or larger and 500 nm or smaller on the surface of the primary particles on the surface of and inside the first lithium nickel composite oxide particles.

7. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium tungstate exists as a film with a thickness of 1 nm or larger and 200 nm or smaller on the surface of the primary particles on the surface of and inside the first lithium nickel composite oxide particles.

8. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium tungstate exists both as a microparticle with a particle diameter of 1 nm or larger and 500 nm or smaller and as a film with a thickness of 1 nm or larger and 200 nm or smaller on the surface of the primary particles on the surface of and inside the first lithium nickel composite oxide particles.

9. A nonaqueous electrolyte secondary battery comprising a positive electrode containing the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 .

10. A method for producing a positive electrode active material of claim 1 for a nonaqueous electrolyte secondary battery, the method comprising mixing first lithium nickel composite oxide particles containing lithium tungstate and second lithium nickel composite oxide particles not containing lithium tungstate, wherein
the first lithium nickel composite oxide particles have a composition represented by Li z1 Ni 1-x1-y1 Co x1 M 1 y1 O 2 (where 0≤x1≤0.35, 0≤y1≤0.35, 0.95≤z1≤1.15, and M 1 is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al), and include a core material containing secondary particles each corresponding to an aggregation of a plurality of primary particles, and the lithium tungstate existing on at least a part of a surface of the primary particles on a surface of and inside the first lithium nickel composite oxide particles, and
the second lithium nickel composite oxide particles have a composition represented by Li z2 Ni 1-x2-y2 Co x2 M 2 y2 O 2 (where 0≤x2≤0.35, 0≤y2≤0.35, 0.95≤z2≤1.15, and M 2 is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al), and include secondary particles each corresponding to an aggregation of a plurality of primary particles.

11. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 10 , wherein the second lithium nickel composite oxide particles are washed with water before the mixing.

12. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 11 , wherein in the washing with water, slurry has a concentration of 500 g/L or higher and 2,500 g/L or lower.

13. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 10 , wherein the amount of lithium contained in a lithium compound other than the lithium tungstate existing on the surface of the primary particles on a surface of and inside both the first lithium nickel composite oxide particles and the second lithium nickel composite oxide particles is 0.05% by mass or less relative to the total amount of the positive electrode active material.

14. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 10 , wherein the first lithium nickel composite oxide particles and the second lithium nickel composite oxide particles are mixed so that the positive electrode active material contains the first lithium nickel composite oxide particles by 10% by mass or more relative to the total amount of the positive electrode active material.

15. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 10 , wherein the first lithium nickel composite oxide particles and the second lithium nickel composite oxide particles are mixed so that the first lithium nickel composite oxide particles contain tungsten by 0.03 at % or more and 2.5 at % or less relative to the total number of atoms of Ni, Co, and M contained in the positive electrode active material.

16. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 10 , the method further comprising: before the mixing, preparing a tungsten mixture containing
a base mate

Assignees

• Sumitomo Metal Mining Co

Inventors

• Kondo Kentaro
• Yokoyama Jun
• Furuichi Yuki

Classifications

• H01M4/1391

  of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/366

  as layered products · CPC title

• H01M4/131 Primary

  Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx · CPC title

• H01M4/04

  Processes of manufacture in general · CPC title