# US 11,444,274 B2 · Positive electrode active material particle

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- Number: US 11,444,274 B2
- Document ID: US11444274B2
- Status: Granted
- Kind: B2
- Application number: 16/914,539
- Filed: 2020-06-29
- Published: 2020-12-17
- Granted: 2022-09-13
- Earliest claimed: 2017-05-12
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Semiconductor Energy Laboratory Co., Ltd.
- Inventors: Masahiro Takahashi; Teruaki Ochiai; Yohei Momma; Ayae Tsuruta
- Web page: https://patentgrep.com/patent/US11444274B2

## CPC

- H01M 4/364: {as mixtures}
- 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)
- H01G 11/06: with one of the electrodes allowing ions to be reversibly doped thereinto, e.g. lithium ion capacitors [LIC]
- H01G 11/30: characterised by their material
- 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 4/622: {being polymers}
- H01M 4/625: {Carbon or graphite}
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A positive electrode active material particle with little deterioration is provided. A power storage device with little deterioration is provided. A highly safe power storage device is provided. The positive electrode active material particle includes a first crystal grain, a second crystal grain; and a crystal grain boundary positioned between the crystal grain and the second crystal grain; the first crystal grain and the second crystal grain include lithium, a transition metal, and oxygen; the crystal grain boundary includes magnesium and oxygen; and the positive electrode active material particle includes a region where the ratio of the atomic concentration of magnesium in the crystal grain boundary to the atomic concentration of the transition metal in first crystal grain and the second crystal grain is greater than or equal to 0.010 and less than or equal to 0.50.

## Claims

### Claim 1

A lithium-ion secondary battery comprising:
a positive electrode active material particle including a plurality of crystal grains, the positive electrode active material particle including a crystal grain boundary inside the positive electrode active material particle, the crystal grain boundary being positioned between a first one of the plurality of the crystal grains and a second one of the plurality of the crystal grains, wherein the first one and the second one are adjacent to each other,
wherein at least the first one of the plurality of the crystal grains includes a composite oxide containing cobalt,
wherein, in EDX linear analysis of the first one of the plurality of the crystal grains, calcium is detected at a level of the lower detection limit, and
wherein, in EDX linear analysis of the crystal grain boundary or a periphery of the crystal grain boundary, calcium is detected beyond the level of the lower detection limit.

### Claim 2 (depends on 1)

The lithium-ion battery according to claim 1,
wherein the crystal grain boundary or the periphery of the crystal grain boundary includes cobalt, and
wherein an atomic concentration of cobalt in the crystal grain boundary or the periphery of the crystal grain boundary is less than an atomic concentration of cobalt in the first one of the plurality of the crystal grains.

### Claim 3 (depends on 1)

The lithium-ion battery according to claim 1,
wherein in EDX linear analysis of the first one of the plurality of the crystal grains, magnesium is detected at the level of the lower detection limit, and
wherein, in EDX linear analysis of the crystal grain boundary or the periphery of the crystal grain boundary, magnesium is detected beyond the level of the lower detection limit.

### Claim 4 (depends on 1)

The lithium-ion battery according to claim 1, further comprising a conductive additive,
wherein the conductive additive includes carbon fiber.

### Claim 5 (depends on 4)

The lithium-ion battery according to claim 4, wherein the carbon fiber includes carbon nanofiber or carbon nanotube.

### Claim 6 (depends on 4)

The lithium-ion battery according to claim 4, wherein the conductive additive further includes any one of carbon black, graphite particle, graphene, and fullerene.

### Claim 7

A lithium-ion secondary battery comprising:
a positive electrode active material particle including a plurality of crystal grains, the positive electrode active material including a crystal grain boundary inside the positive electrode active material particle, the crystal grain boundary being positioned between a first one of the plurality of the crystal grains and a second one of the plurality of the crystal grains, wherein the first one and the second one are adjacent to each other,
wherein at least the first one of the plurality of the crystal grains includes a composite oxide containing cobalt, and
wherein, in EDX linear analysis of the first one of the plurality of the crystal grains, the second one of the plurality of the crystal grains, and the crystal grain boundary, a peak of calcium is observed at the crystal grain boundary or a periphery of the crystal grain boundary.

### Claim 8 (depends on 7)

The lithium-ion battery according to claim 7,
wherein the crystal grain boundary or the periphery of the crystal grain boundary includes cobalt, and
wherein an atomic concentration of cobalt in the crystal grain boundary or the periphery of the crystal grain boundary is less than an atomic concentration of cobalt in the first one of the plurality of the crystal grains.

### Claim 9 (depends on 7)

The lithium-ion battery according to claim 7, wherein, in EDX linear analysis of the first one of the plurality of the crystal grains, the second one of the plurality of the crystal grains, and the crystal grain boundary, a peak of magnesium is observed at the crystal grain boundary or the periphery of the crystal grain boundary.

### Claim 10 (depends on 7)

The lithium-ion battery according to claim 7, further comprising a conductive additive,
wherein the conductive additive includes carbon fiber.

### Claim 11 (depends on 10)

The lithium-ion battery according to claim 10, wherein the carbon fiber includes carbon nanofiber or carbon nanotube.

### Claim 12 (depends on 10)

The lithium-ion battery according to claim 10, wherein the conductive additive further includes any one of carbon black, graphite particle, graphene, and fullerene.

### Claim 13

A lithium-ion secondary battery comprising:
a positive electrode active material particle including a plurality of crystal grains, the positive electrode active material particle including a crystal grain boundary inside the positive electrode active material particle, the crystal grain boundary being positioned between a first one of the plurality of the crystal grains and a second one of the plurality of the crystal grains, wherein the first one and the second one are adjacent to each other,
wherein at least the first one of the plurality of the crystal grains includes a composite oxide containing cobalt, and
wherein an atomic concentration of calcium in the crystal grain boundary or a periphery of the crystal grain boundary is larger than an atomic concentration of calcium in the first one of the plurality of the crystal grains.

### Claim 14 (depends on 13)

The lithium-ion battery according to claim 13,
wherein the crystal grain boundary or the periphery of the crystal grain boundary includes cobalt, and
wherein an atomic concentration of cobalt in the crystal grain boundary or the periphery of the crystal grain boundary is less than an atomic concentration of cobalt in the first one of the plurality of the crystal grains.

### Claim 15 (depends on 13)

The lithium-ion battery according to claim 13, wherein an atomic concentration of magnesium in the crystal grain boundary or the periphery of the crystal grain boundary is larger than an atomic concentration of magnesium in the first one of the plurality of the crystal grains.

### Claim 16 (depends on 13)

The lithium-ion battery according to claim 13, wherein, when the first one of the plurality of the crystal grains is compared with the crystal grain boundary or with the periphery of the crystal grain boundary, calcium in the first one of the plurality of the crystal grains does not substantially exist.

### Claim 17 (depends on 13)

The lithium-ion battery according to claim 13,
wherein, when the first one of the plurality of the crystal grains is compared with the crystal grain boundary or with the periphery of the crystal grain boundary, calcium in one of the plurality of the crystal grains does not substantially exist, and
wherein, when the first one of the plurality of the crystal grains is compared with the crystal grain boundary or with the periphery of the crystal grain boundary, magnesium in the first one of the plurality of the crystal grains does not substantially exist.

### Claim 18 (depends on 13)

The lithium-ion battery according to claim 13, further comprising a conductive additive,
wherein the conductive additive includes carbon fiber.

### Claim 19 (depends on 18)

The lithium-ion battery according to claim 18, wherein the carbon fiber includes carbon nanofiber or carbon nanotube.

### Claim 20 (depends on 18)

The lithium-ion battery according to claim 18, wherein the conductive additive further includes any one of carbon black, graphite particle, graphene, and fullerene.

### Claim 21

A lithium-ion secondary battery comprising:
a positive electrode active material particle including a plurality of crystal grains, the positive electrode active material particle including a crystal grain boundary inside the positive electrode active material particle, the crystal grain boundary being positioned between a first one of the plurality of the crystal grains and a second one of the plurality of the crystal grains where the first one and the second one are adjacent to each other,
wherein at least the first one of the plurality of the crystal grains includes a composite oxide containing cobalt,
wherein, in EDX linear analysis of the first one of the plurality of the crystal grains, calcium is not detected, and
wherein, in EDX linear analysis of the crystal grain boundary or a periphery of the crystal grain boundary, calcium is detected beyond a level of a lower detection limit.

### Claim 22 (depends on 21)

The lithium-ion battery according to claim 21,
wherein the crystal grain boundary or the periphery of the crystal grain boundary includes cobalt, and
wherein an atomic concentration of cobalt in the crystal grain boundary or the periphery of the crystal grain boundary is less than an atomic concentration of cobalt in the first one of the plurality of the crystal grains.

### Claim 23 (depends on 21)

The lithium-ion battery according to claim 21, wherein in EDX linear analysis for the first one of the plurality of the crystal grains, magnesium is not detected,
wherein, in EDX linear analysis for the crystal grain boundary or the periphery of the crystal grain boundary, magnesium is detected beyond the level of the lower detection limit.

### Claim 24 (depends on 21)

The lithium-ion battery according to claim 21, further comprising a conductive additive,
wherein the conductive additive includes carbon fiber.

### Claim 25 (depends on 24)

The lithium-ion battery according to claim 24, wherein the carbon fiber includes carbon nanofiber or carbon nanotube.

### Claim 26 (depends on 24)

The lithium-ion battery according to claim 24, wherein the conductive additive further includes any one of carbon black, graphite particle, graphene, and fullerene.