# US 10,483,526 B2 · Positive electrode active material, nonaqueous electrolyte battery, and battery pack

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- Number: US 10,483,526 B2
- Document ID: US10483526B2
- Status: Granted
- Kind: B2
- Application number: 14/200,414
- Filed: 2014-03-07
- Published: 2014-10-02
- Granted: 2019-11-19
- Earliest claimed: 2013-03-26
- Assignees: Kabushiki Kaisha Toshiba
- Applicants: Kabushiki Kaisha Toshiba
- Inventors: Norio Takami; Keigo Hoshina; Hiroki Inagaki
- Web page: https://patentgrep.com/patent/US10483526B2

## CPC

- H01M 4/136: Electrodes based on inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy
- H01M 4/366: {as layered products}
- H01M 4/485: of mixed oxides or hydroxides for inserting or intercalating light metals, e.g. LiTi2O4 or LiTi2OxFy (H01M4/505, H01M4/525 take precedence)
- H01M 4/5825: {Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines}
- H01M 4/625: {Carbon or graphite}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

According to one embodiment, there is provided a positive electrode active material containing positive electrode active material particles. The positive electrode active material particles have an olivine structure. The positive electrode active material particles are represented by LiMn1−x−yFexMyPO4 (0<x≤0.5, 0≤y≤0.2, and M is at least one element selected from the group consisting of Mg, Ni, Co, Sn, and Nb) and satisfy, Formula (1) below. β<α (1), wherein α is a ratio of Fe in LiMn1−α−yFeαMyPO4, and β is a ratio of Fe in LiMn1−β−yFeβMyPO4.

## Claims

### Claim 1

A nonaqueous electrolyte battery comprising:
a positive electrode comprising a positive electrode active material;
a negative electrode; and
a nonaqueous electrolyte,
wherein the positive electrode active material comprises positive electrode active material primary particles which have an olivine structure, are represented by LiMn1−x−yFexMyPO4 where 0≤x≤0.5, 0≤y≤0.2 where M is at least one element selected from the group consisting of Mg, Ni, Co, Sn, and Nb, and satisfy Formula (1) below:
β<α (1)
wherein the positive electrode active material primary particles comprise a surface portion, α is a ratio of Fe in LiMn1−α−yFeαMyPO4 which is a composition of the surface portion of the positive electrode active material primary particles, and β is a ratio of Fe in LiMn1−β−yFeβMyPO4 which is a composition of a central portion of the positive electrode active material primary particles,
wherein the composition of the surface portion of the positive electrode active material primary particles is a composition of a portion having a thickness of 1 to 10 nm from a surface of a cross section of the positive electrode active material primary particle, and the composition of the central portion of the positive electrode active material primary particles is a composition of a peripheral portion within a range of 1 to 10 nm from a center of gravity of the cross section of the same positive electrode active material primary particle,
wherein an average diameter of the positive electrode active material primary particles is from 0.01 to 1 μm,
and wherein the negative electrode comprises a negative electrode active material comprising at least one oxide selected from the group consisting of titanium dioxide having a monoclinic system structure and a niobium titanium oxide.

### Claim 2 (depends on 1)

A battery pack comprising the nonaqueous electrolyte battery according to claim 1.

### Claim 3 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein 0<y≤0.2.

### Claim 4 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein the composition of the surface portion of the positive electrode active material primary particles and the composition of the central portion of the positive electrode active material primary particles contain the same elements, and both contain Fe.

### Claim 5 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein the composition of the surface portion of the positive electrode active material primary particles and the composition of the central portion of the positive electrode active material primary particles consist of the same elements.

### Claim 6 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein α is 0.1≤α<1, and the positive electrode active material further comprises a carbon-containing material which coats at least a part of the surface portion of the positive electrode active material primary particles.

### Claim 7 (depends on 6)

The nonaqueous electrolyte battery according to claim 6, wherein the carbon-containing material comprises a carbonaceous material having an interplanar spacing d002 of 0.344 nm or more derived from (002) reflection according to a powder X-ray diffraction.

### Claim 8 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein β is 0<β≤0.5.

### Claim 9 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein α is 0.35≤α≤0.5, β is 0<β≤0.3, and the positive electrode active material further comprises a carbon-containing material which coats at least a part of the surface portion of the positive electrode active material primary particles.

### Claim 10 (depends on 9)

The nonaqueous electrolyte battery according to claim 9, wherein the carbon-containing material comprises a carbonaceous material having an interplanar spacing d002 of 0.344 nm or more derived from (002) reflection according to the powder X-ray diffraction.

### Claim 11 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein an average diameter of the positive electrode active material primary particles is from 0.01 to 0.5 μm.

### Claim 12 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein the negative electrode active material comprises titanium dioxide having a monoclinic system structure.

### Claim 13 (depends on 1)

The nonaqueous electrolyte battery according to claim 1, wherein the negative electrode active material comprises a niobium titanium oxide.