# US 2020/0403218 A1 · Positive electrode active material for nonaqueous electrolyte secondary battery, method for producing same, and nonaqueous electrolyte secondary battery using said positive electrode active material

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- Number: US 2020/0403218 A1
- Document ID: US20200403218A1
- Status: Published application
- Kind: A1
- Application number: 17/007,707
- Filed: 2020-08-31
- Published: 2020-12-24
- Earliest claimed: 2015-04-24
- Assignees: Sumitomo Metal Mining Co., Ltd.
- Applicants: Sumitomo Metal Mining Co., Ltd.
- Inventors: Yuki Furuichi; Tetsufumi Komukai; Hiroyuki Toya
- Web page: https://patentgrep.com/patent/US20200403218A1

## CPC

- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01B 1/08: oxides
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/366: {as layered products}
- H01M 4/505: of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy
- H01M 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- C01P 2002/50: Solid solutions
- C01P 2002/52: containing elements as dopants
- C01P 2004/03: obtained by SEM
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2004/64: Nanometer sized, i.e. from 1-100 nanometer
- C01P 2006/12: Surface area
- C01P 2006/80: Compositional purity
- H01M 2220/20: Batteries in motive systems, e.g. vehicle, ship, plane
- H01M 2220/30: Batteries in portable systems, e.g. mobile phone, laptop
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K})
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Provided is a method for producing the positive electrode active material for nonaqueous electrolyte secondary batteries, including a first step of mixing a Li-metal composite oxide powder which is represented by the general formula: LizNi1-x-yCoxMyO2 (where 0≤x≤0.35, 0·y≤0.35, and 0.97≤z≤1.30 are satisfied, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti and Al) and constituted by primary particles and secondary particles, to an alkaline solution with a W compound dissolved therein, and immersing a resulting mixture, followed by solid-liquid separation, to obtain a W mixture with W uniformly dispersed on the surface of the primary particles of the composite oxide, and a second step of heat-treating the W mixture to thereby form a compound containing W and Li on the surface of the primary particles of the composite oxide powder.

## Claims

### Claim 1

A method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries, comprising:
a first step of mixing a lithium-metal composite oxide powder which is represented by a general formula: LizNi1-x-yCoxMyO2 (where 0≤x≤0.35, 0≤y≤0.35, and 0.95≤z≤1.30 are satisfied, and M is at least one element selected from Mn, V, Mg, Mo, Nb, Ti and Al) and has a layered crystal structure constituted by primary particles and secondary particles formed by aggregation of the primary particles, to an alkaline solution with a tungsten compound dissolved therein at a tungsten concentration of 0.1 to 2 mol/L so that a solid-liquid ratio of the lithium-metal composite oxide powder to an amount of water in the alkaline solution falls within a range of 200 to 2500 g/L, and immersing a resulting mixture, followed by solid-liquid separation, to obtain a tungsten-containing mixture in which tungsten is uniformly dispersed on a surface of the primary particles of the lithium-metal composite oxide; and
a second step of subjecting the tungsten-containing mixture to heat treatment to thereby form a compound containing tungsten and lithium on the surface of the primary particles of the lithium-metal composite oxide.

### Claim 2 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, further comprising a water washing step of washing the lithium-metal composite oxide powder with water, before the first step is performed.

### Claim 3 (depends on 2)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 2, wherein the tungsten-containing mixture contains tungsten in an amount of 3.0 at % or less with respect to a total number of atoms of Ni, Co and M contained in the lithium-metal composite oxide powder used in the mixing.

### Claim 4 (depends on 3)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 3, wherein the alkaline solution with the tungsten compound dissolved therein has a tungsten concentration of 0.05 to 2 mol/L.

### Claim 5 (depends on 4)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 4, wherein the alkaline solution is made by dissolving a tungsten compound in an aqueous lithium hydroxide solution.

### Claim 6 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the mixing of the alkaline solution with the tungsten compound dissolved therein with the lithium-metal composite oxide powder is performed in the alkaline solution of the tungsten compound as a liquid and at a temperature of 50° C. or less.

### Claim 7 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the heat treatment of the second step is performed in an oxygen atmosphere or a vacuum atmosphere at 100 to 600° C.

### Claim 8 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the tungsten-containing mixture contains tungsten in an amount of 3.0 at % or less with respect to a total number of atoms of Ni, Co and M contained in the lithium-metal composite oxide powder used in the mixing.

### Claim 9 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the alkaline solution with the tungsten compound dissolved therein has a tungsten concentration of 0.05 to 2 mol/L.

### Claim 10 (depends on 1)

The method of producing a positive electrode active material for nonaqueous electrolyte secondary batteries according to claim 1, wherein the alkaline solution is made by dissolving a tungsten compound in an aqueous lithium hydroxide solution.