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-11735726-B2
Application number	US-201716473045-A
Country	US
Kind code	B2
Filing date	Dec 25, 2017
Priority date	Dec 26, 2016
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A positive electrode active material for a nonaqueous electrolyte secondary battery is disclosed which contains a lithium-nickel-manganese composite oxide containing a secondary particle formed of a plurality of flocculated primary particles and a lithium-niobium compound. The positive electrode active material is represented by General Formula (1): LidNi1−a−b−cMnaMbNbcO2+γ (M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.03≤a≤0.60, 0≤b≤0.60, 0.02≤c≤0.08, a+b+c<1, 0.95≤d≤1.20, and 0≤γ≤0.5, the lithium-nickel-manganese composite oxide has a (003)-plane crystallite diameter of at least 50 nm and up to 130 nm, the lithium-niobium compound is present on surfaces of the primary particles, and part of niobium in the positive electrode active material is solid-solved in the 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 a lithium-nickel-manganese composite oxide containing a secondary particle formed of a plurality of flocculated primary particles and a lithium-niobium compound, wherein
the positive electrode active material is represented by General Formula (1): Li d Ni 1−a−b−c Mn a M b Nb c O 2+γ (in General Formula (1), M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.12≤a≤0.60, 0≤b≤0.60, 0.025≤c≤0.04, a+b+c<1, 0.95≤d≤1.20, and 0≤γ≤0.5),
the lithium-nickel-manganese composite oxide has a (003)-plane crystallite diameter of at least 50 nm and up to 130 nm,
the lithium-niobium compound is present on surfaces of the primary particles, and
part of niobium in the positive electrode active material is solid-solved in the primary particles.

2. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium-niobium compound contains at least one of Li 3 NbO 4 , LiNbO 3 , Li 5 NbO 5 , LiNb 3 O 8 , and Li 8 Nb 2 O 9 .

3. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the lithium-niobium compound contains an amorphous phase.

4. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the positive electrode active material has a volume average particle diameter MV of at least 5 μm and up to 20 μm.

5. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein the secondary particle has an average degree of circularity E of at least 0.60 and up to 0.98, the degree being determined by the following Expression (1):
E= 4π S/L 2   Expression (1):

(in the above expression, S is a projected area of the secondary particle, L is a circumferential length of the secondary particle, and π is the ratio of the circumference of a circle to its diameter).

6. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 5 , wherein the average degree of circularity E is at least 0.7 and up to 0.98.

7. The positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 , wherein 0.12≤a≤0.45 in the General Formula (1).

8. A nonaqueous electrolyte secondary battery comprising:
a positive electrode;
a negative electrode; and
a nonaqueous electrolyte,
the positive electrode comprising the positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 1 .

9. A positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising a lithium-nickel-manganese composite oxide containing a secondary particle formed of a plurality of flocculated primary particles and a lithium-niobium compound, wherein
the positive electrode active material is represented by General Formula (1): Li d Ni 1−a−b−c Mn a M b Nb c O 2+γ (in General Formula (1), M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.12≤a≤0.45, 0≤b≤0.60, 0.02≤c≤0.08, a+b+c<1, 0.95≤d≤1.20, and 0≤γ≤0.5),
the lithium-nickel-manganese composite oxide has a (003)-plane crystallite diameter of at least 50 nm and up to 130 nm,
the lithium-niobium compound is present on surfaces of the primary particles, and
part of niobium in the positive electrode active material is solid-solved in the primary particles.

10. A method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery, the positive electrode active material comprising a lithium-nickel-manganese composite oxide containing a secondary particle formed of a plurality of flocculated primary particles and a lithium-niobium compound, the method comprising:
preparing a lithium-niobium mixture containing nickel-manganese composite hydroxide particles represented by General Formula (2): Ni 1−a−b Mn a M b (OH) 2+α (in Formula (2), M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.12≤a≤0.60, 0≤b≤0.60, and 0≤α≤0.4), a niobium compound, and a lithium compound; and
firing the lithium-niobium mixture in an oxidizing atmosphere at at least 750° C. and up to 1,000° C. to obtain the lithium-nickel-manganese composite oxide and the lithium-niobium compound, wherein
the positive electrode active material is represented by General Formula (1): Li d Ni 1−a−b−c Mn a M b Nb c O 2+γ (in General Formula (1), M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.12≤a≤0.60, 0≤b≤0.60, 0.025≤c≤0.04, and 0.95≤d≤1.20, and, and 0≤γ≤0.5),
the lithium-niobium compound is present on surfaces of the primary particles, and
part of niobium in the positive electrode active material is solid-solved in the primary particles.

11. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , wherein the preparing comprises:
obtaining the nickel-manganese composite hydroxide particles by crystallization; and
mixing the nickel-manganese composite hydroxide particles, the lithium compound, and the niobium compound with an average particle diameter of at least 0.01 μm and up to 10 together to prepare the lithium-niobium mixture.

12. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , wherein the niobium compound is either one or both of niobic acid and niobium oxide.

13. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , wherein the preparing comprises:
obtaining the nickel-manganese composite hydroxide particles by crystallization;
adding a niobium salt solution and an acid to slurry obtained by mixing the nickel-manganese composite hydroxide particles and water together to obtain nickel-manganese composite hydroxide particles coated with a niobium compound; and
mixing the nickel-manganese composite hydroxide particles coated with the niobium compound and the lithium compound together to prepare the lithium-niobium mixture.

14. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , the method comprising thermally treating the nickel-manganese composite hydroxide particles at a temperature of at least 105° C. and up to 700° C. before preparing the lithium-niobium mixture, wherein
the preparing prepares a lithium-niobium mixture containing either one or both of nickel-manganese composite hydroxide particles and nickel-manganese composite oxide particles obtained by the thermally treating, a niobium compound, and a lithium compound.

15. The method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 6 , wherein the lithium-niobium mixture is fired at at least 850° C.

16. A method for producing a positive electrode active material for a nonaqueous electrolyte secondary battery according to claim 15 , the method comprising:
preparing a lithium-niobium mixture containing nickel-manganese composite hydroxide particles represented by General Formula (2): Ni 1−a−b Mn a M b (OH) 2+α (in Formula (2), M is at least one element selected from Co, W, Mo, V, Mg, Ca, Al, Ti, Cr, Zr, and Ta; and 0.12≤a≤0.45, 0≤b≤0.60, a

Assignees

• Sumitomo Metal Mining Co

Inventors

• KANEDA Haruki
• Koshika Yuki
• Nakamura Takuma

Classifications

• C01G53/82

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

• H01M4/505 Primary

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/0471

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

• H01M10/0525

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