# US 10,770,724 B2 · Positive electrode material for lithium secondary batteries

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- Number: US 10,770,724 B2
- Document ID: US10770724B2
- Status: Granted
- Kind: B2
- Application number: 16/190,841
- Filed: 2018-11-14
- Published: 2019-05-16
- Granted: 2020-09-08
- Earliest claimed: 2017-11-16
- Assignees: Toyota Jidosha Kabushiki Kaisha
- Applicants: Toyota Jidosha Kabushiki Kaisha
- Inventors: Ryuta Sugiura
- Web page: https://patentgrep.com/patent/US10770724B2

## CPC

- H01M 4/366: {as layered products}
- H01M 4/04: Processes of manufacture in general
- H01M 4/0416: {involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence)}
- H01M 4/1391: of electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- 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 10/052: Li-accumulators
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

Provided is a positive electrode material that allows reducing the resistance of a lithium secondary battery. The positive electrode material for lithium secondary batteries disclosed herein contains positive electrode active material particles each having a layered structure; and at least one conductor selected from the group consisting of a lithium conductor and an electronic conductor, and disposed on a surface of the positive electrode active material particles. In a case where the positive electrode material contains the lithium conductor, the proportion of the lithium conductor disposed at planes other than the (003) plane of the positive electrode active material particle, with respect to the total amount of the lithium conductor, is not less than 50% and not more than 100%. In a case where the positive electrode material contains the electronic conductor the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particle, with respect to the total amount of the electronic conductor, is not less than 50% and not more than 100%.

## Claims

### Claim 1

A positive electrode material for lithium secondary batteries, the material comprising:
positive electrode active material particles each having a layered structure;
an electronic conductor disposed on a surface of the positive electrode active material particles; and
optionally a lithium conductor disposed on the surface of the positive electrode active material particles,
wherein the electronic conductor is a perovskite-type oxide represented by ABO3-δ where A is the combination of La and at least one element selected from the group consisting of Ca, Sr and Ba; B is a combination of Co and at least one element selected from the group consisting of Mn and Ni, and δ is an oxygen deficiency value for achieving electrical neutrality,
wherein in a case where the positive electrode material contains the lithium conductor, the proportion of the lithium conductor disposed at planes other than the (003) plane of the positive electrode active material particles, with respect to a total amount of the lithium conductor disposed on the surface of the positive electrode active material particles, is not less than 50% and not more than 100%;
the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particles, with respect to at total amount of the electronic conductor disposed on the surface of the positive electrode active material particles, is not less than 50% and not more than 100%.

### Claim 2 (depends on 1)

The positive electrode material for lithium secondary batteries according to claim 1, wherein the proportion of the lithium conductor disposed at planes other than the (003) plane of the positive electrode active material particles, with respect to the total amount of the lithium conductor disposed on the surface of the positive electrode active material particles, is not less than 70% and not more than 100%.

### Claim 3 (depends on 1)

The positive electrode material for lithium secondary batteries according to claim 1, wherein the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particles, with respect to the total amount of the electronic conductor disposed on the surface of the positive electrode active material particles, is not less than 70% and not more than 100%.

### Claim 4 (depends on 1)

The positive electrode material for lithium secondary batteries according to claim 1, wherein the positive electrode material contains the lithium conductor.

### Claim 5

A method for producing a positive electrode material for lithium secondary batteries,
the method comprising the steps of:
preparing positive electrode active material particles each having a layered structure, an electronic conductor having a positive charge, and optionally a lithium conductor having a negative charge; and
mixing the positive electrode active material particles, the electronic conductor, and optionally the lithium conductor,
wherein the electronic conductor is a perovskite-type oxide represented by ABO3-δ where A is the combination of La and at least one element selected from the group consisting of Ca, Sr and Ba; B is a combination of Co and at least one element selected from the group consisting of Mn and Ni, and δ is an oxygen deficiency value for achieving electrical neutrality.

### Claim 6 (depends on 5)

The method according to claim 5, wherein:
in a case where the positive electrode material contains the lithium conductor, the proportion of the lithium conductor disposed at planes other than the (003) plane of the positive electrode active material particles, with respect to a total amount of the lithium conductor disposed on the surface of the positive electrode active material particles, is not less than 50% and not more than 100%; and
the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particles, with respect to at total amount of the electronic conductor disposed on the surface of the positive electrode active material particles, is not less than 50% and not more than 100%.

### Claim 7 (depends on 5)

The method according to claim 5, wherein the proportion of the lithium conductor disposed at planes other than the (003) plane of the positive electrode active material particles, with respect to the total amount of the lithium conductor disposed on the surface of the positive electrode active material particles, is not less than 70% and not more than 100%.

### Claim 8 (depends on 5)

The method according to claim 5, wherein the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particles, with respect to the total amount of the electronic conductor disposed on the surface of the positive electrode active material particles, is not less than 70% and not more than 100%.

### Claim 9 (depends on 5)

The method according to claim 5, wherein the positive electrode material contains the lithium conductor.

### Claim 10 (depends on 2)

The positive electrode material for lithium secondary batteries according to claim 2, wherein the proportion of the electronic conductor disposed at the (003) plane of the positive electrode active material particles, with respect to the total amount of the electronic conductor disposed on the surface of the positive electrode active material particles, is not less than 70% and not more than 100%.