Positive electrode active material for nonaqueous electrolyte secondary battery, and nonaqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-2018226646-A1
Application number	US-201615748338-A
Country	US
Kind code	A1
Filing date	Jun 21, 2016
Priority date	Jul 30, 2015
Publication date	Aug 9, 2018
Grant date	—

Abstract

Provided is a positive electrode active material for nonaqueous electrolyte secondary batteries that is represented by the general formula (1): Li a Ni 1-x-y Co x M y W z O 2+α (where 0≤x≤0.35, 0≤y≤0.35, 0.0008≤z≤0.030, 0.97≤a≤1.25, and 0≤α≤0.20, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al) and is constituted by a Li-metal composite oxide composed of primary particles and secondary particles formed by aggregation of the primary particles, wherein a compound including Li and W is formed on the surface of the primary particles of the composite oxide and the amount of W contained in the compound is such that the number of atoms of W is 0.08 to 0.30 at % with respect to the total number of atoms of Ni, Co, and M contained in the positive electrode active material.

First claim

1 . A positive electrode active material for nonaqueous electrolyte secondary batteries represented by the general formula (1): Li a Ni 1-x-y Co x M y W z O 2+α (where 0≤x≤0.35, 0≤y≤0.35, 0.0008≤z≤0.030, 0.97≤a≤1.25, and 0≤α≤0.20 are satisfied, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al) and constituted by a lithium-metal composite oxide composed of primary particles and secondary particles formed by aggregation of the primary particles,
wherein a compound containing lithium and tungsten is formed on a surface of the primary particles of the lithium-metal composite oxide, and
wherein an amount of tungsten contained in the compound is such that the number of atoms of W is 0.08 to 0.30 at % with respect to the total number of atoms of Ni, Co, and M contained in the positive electrode active material.

2 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
50% or more of tungsten contained in the compound is present in a form of Li 4 WO 5 .

3 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 2 , wherein
a porosity measured in cross-sectional observation of the secondary particles is 0.15 to 3%.

4 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 3 , wherein
a specific surface area measured by a BET method is 0.9 to 1.5 m 2 /g.

5 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 4 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide as fine particles having a particle size of 1 to 200 nm.

6 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 4 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide as a coating film having a film thickness of 1 to 100 nm.

7 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 4 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide in both forms of fine particles having a particle size of 1 to 200 nm and a coating film having a film thickness of 1 to 100 nm.

8 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 7 , wherein
the lithium-metal composite oxide is represented by the general formula (2): Li b Ni 1-x-y Co x M y O 2 (where 0≤x≤0.35, 0≤y≤0.35, and 0.95≤b≤1.20 are satisfied, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al).

9 . A nonaqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 8 .

10 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
a porosity measured in cross-sectional observation of the secondary particles is 0.15 to 3%.

11 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
a specific surface area measured by a BET method is 0.9 to 1.5 m 2 /g.

12 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide as fine particles having a particle size of 1 to 200 nm.

13 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide as a coating film having a film thickness of 1 to 100 nm.

14 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
the compound is present on the surface of the primary particles of the lithium-metal composite oxide in both forms of fine particles having a particle size of 1 to 200 nm and a coating film having a film thickness of 1 to 100 nm.

15 . The positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 , wherein
the lithium-metal composite oxide is represented by the general formula (2): Li b Ni 1-x-y Co x M y O 2 (where 0≤x≤0.35, 0≤y≤0.35, and 0.95≤b≤1.20 are satisfied, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti, and Al).

16 . A nonaqueous electrolyte secondary battery comprising:
a positive electrode comprising the positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1 .

Assignees

• Sumitomo Metal Mining Co

Inventors

• Furuichi Yuki
• Suzuki Jun
• Komukai Tetsufumi

Classifications

• 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

• H01M2004/021

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

• H01M4/366 Primary

  as layered products · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title

• C01P2004/50

  Agglomerated particles · CPC title