Manganese composite hydroxide and process for producing same, positive electrode active material and process for producing same, and non-aqueous electrolyte secondary battery

Patent metadata

Field	Value
Publication number	US-11973223-B2
Application number	US-202016996959-A
Country	US
Kind code	B2
Filing date	Aug 19, 2020
Priority date	Jun 27, 2014
Publication date	Apr 30, 2024
Grant date	Apr 30, 2024

Abstract

Provided is a precursor of a positive electrode active material for non-aqueous electrolyte secondary batteries which allows a non-aqueous electrolyte secondary battery to have excellent battery characteristics. A manganese composite hydroxide is obtained by adjusting the pH value of an aqueous solution for nucleation containing cobalt and/or manganese to 7.5 to 11.1 on the basis of a liquid temperature of 25° C. to form plate-shaped crystal nuclei, and adjusting the pH value of a slurry for particle growth containing the plate-shaped crystal nuclei to 10.5 to 12.5 on the basis of a liquid temperature of 25° C., and supplying a mixed aqueous solution including a metal compound containing at least manganese to the slurry, thereby performing particle growth of the plate-shaped crystal nuclei.

First claim

The invention claimed is:

1. A manganese composite hydroxide represented by Ni x Co y Mn z M t (OH) 2+A (where x satisfies 0≤x≤0.5; y satisfies 0≤y≤0.5; z satisfies 0.35<z<0.8; t satisfies 0≤t≤0.1; A satisfies 0≤A≤0.5; x+y+z+t=1; and M is at least one additive element selected from the group consisting of V, Mg, Al, Ti, Mo, Nb, Zr, and W),
wherein the manganese composite hydroxide comprises secondary particles in each of which spherical or clumped manganese composite hydroxide particles each formed of an aggregate of a plurality of primary particles are two-dimensionally connected, and
wherein a volume average particle size (Mv) measured by laser diffraction scattering is 4 μm to 20 μm; and a ratio (Mv/L) of the volume average particle size to a width (L) of the secondary particle in a direction perpendicular to a connecting direction of the manganese composite hydroxide particles is from 3 to 20.

2. The manganese composite hydroxide according to claim 1 , wherein [(D90−D10)/Mv] is not more than 0.70, the [(D90−D10)/Mv] representing a variation index of particle size calculated using D90 and D10 in a particle size distribution measured by laser diffraction scattering and the volume average particle size (Mv).

3. The manganese composite hydroxide according to claim 1 , wherein the secondary particle has a high concentration layer of cobalt and/or manganese in a width-direction center thereof.

4. The manganese composite hydroxide according to claim 3 , wherein the high concentration layer has a thickness of 0.01 μm to 1 μm.

5. The manganese composite hydroxide according to claim 1 , being a precursor of a positive electrode active material for non-aqueous electrolyte secondary batteries.

6. A process for producing a manganese composite hydroxide represented by Ni x Co y Mn z M t (OH) 2+A (where x satisfies 0≤x≤0.5; y satisfies 0≤y≤0.5; z satisfies 0.35<z<0.8; t satisfies 0≤t≤0.1; A satisfies 0≤A≤0.5; x+y+z+t=1; and M is at least one additive element selected from the group consisting of V, Mg, Al, Ti, Mo, Nb, Zr, and W), the process comprising:
a nucleation step of adjusting a pH value of an aqueous solution for nucleation including at least a metal compound containing cobalt and/or manganese to 7.5 to 11.1 on a basis of a liquid temperature of 25° C. to form plate-shaped crystal nuclei; and
a particle growth step of adjusting a pH value of a slurry for particle growth containing the plate-shaped crystal nuclei formed in the nucleation step to 10.5 to 12.5 and to be higher than the pH value in the nucleation step on a basis of a liquid temperature of 25° C., and supplying a mixed aqueous solution containing a metal compound to the slurry for particle growth to perform particle growth of the plate-shaped crystal nuclei until a ratio (Mv/L) of a volume average particle size (Mv) measured by laser diffraction scattering to a width (L) of the secondary particle in a direction perpendicular to a connecting direction of manganese composite hydroxide particles becomes in a range of from 3 to 20.

7. The process for producing the manganese composite hydroxide according to claim 6 , wherein, in the nucleation step, the crystal nuclei are formed in a non-oxidizing atmosphere of an oxygen concentration of not more than 5% by volume.

8. The process for producing the manganese composite hydroxide according to claim 6 , wherein, in the particle growth step, the slurry for particle growth has an ammonia concentration of 5 g/L to 20 g/L.

9. The process for producing the manganese composite hydroxide according to claim 6 , wherein the slurry for particle growth is obtained by adjusting a pH value of a plate-shaped-crystal-nuclei-containing slurry containing the plate-shaped crystal nuclei obtained in the nucleation step.

10. The process for producing the manganese composite hydroxide according to claim 6 , wherein the manganese composite hydroxide is a precursor of a positive electrode active material for non-aqueous electrolyte secondary batteries.

11. A process for producing a positive electrode active material for non-aqueous electrolyte secondary batteries, the positive electrode active material being formed of a lithium transition metal composite oxide represented by Li 1+u Ni x Co y Mn z M t O 2+α (where u satisfies −0.05≤u<0.60, x satisfies 0≤x≤0.5; y satisfies 0≤y≤0.5; z satisfies 0.35≤z<0.8; t satisfies 0≤t≤0.1; x+y+z+t=1; 0≤α<0.6; and M is at least one additive element selected from the group consisting of V, Mg, Al, Ti, Mo, Nb, Zr, and W),
the process comprising:
a mixing step of mixing the manganese composite hydroxide according to claim 5 with a lithium compound to prepare a lithium mixture; and
a firing step of firing the lithium mixture prepared in the mixing step at a temperature of 650° C. to 1,000° C. in an oxidizing atmosphere.

12. The process for producing the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 11 , wherein a ratio (Li/ME) of the atomic number (Li) of lithium to the sum of the atomic number (ME) of metals other than lithium in the lithium mixture is from 0.95 to 1.60.

13. The process for producing the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 11 , the process further comprising a heat treatment step of heat-treating the manganese composite hydroxide at a temperature of 300° C. to 750° C. in a non-reducing atmosphere before the mixing step.

14. The process for producing the positive electrode active material for non-aqueous electrolyte secondary batteries according to claim 11 , wherein an oxidizing atmosphere in the firing step contains 18% by volume to 100% by volume of oxygen.

Assignees

• Sumitomo Metal Mining Co

Inventors

• Ryoshi Kazuomi
• Mori Kensaku

Classifications

• C01G53/82

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

• C01G53/006

  Chemistry & Metallurgy · mapped topic

• C01G53/50

  of the type (MnO2)n-, e.g. Li(NixMn1-x)O2 or Li(MyNixMn1-x-y)O2 · CPC title

• H01M4/366

  as layered products · CPC title