# US 12,009,506 B2 · Nonaqueous electrolyte secondary battery

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- Number: US 12,009,506 B2
- Document ID: US12009506B2
- Status: Granted
- Kind: B2
- Application number: 16/930,746
- Filed: 2020-07-16
- Published: 2021-01-21
- Granted: 2024-06-11
- Earliest claimed: 2019-07-18
- Assignees: Toyota Jidosha Kabushiki Kaisha; Sumitomo Metal Mining Co., Ltd.
- Applicants: Toyota Jidosha Kabushiki Kaisha; Sumitomo Metal Mining Co., Ltd.
- Inventors: Yuji Yamamoto; Momoko Procter; Yoshinari Makimura; Tetsutaro Hayashi; Willy Shun Kai Bong
- Web page: https://patentgrep.com/patent/US12009506B2

## CPC

- H01M 4/366: {as layered products}
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- 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 4/525: of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 2004/027: {Negative electrodes}
- H01M 2004/028: {Positive electrodes}
- Y02E 60/10: Energy storage using batteries
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- 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
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS

## Abstract

The present disclosure can bring excellent output characteristics to a nonaqueous electrolyte secondary battery that uses a cathode active material containing tungsten while desired durability is secured. The battery of the present disclosure includes a cathode, an anode, and a nonaqueous electrolyte. The cathode includes a cathode active material layer that contains a granular cathode active material. The cathode active material includes a core part that contains a lithium-transition metal composite oxide of a layered structure; a tungsten-concentrated layer that is formed over a surface of the core part and has a higher tungsten concentration than in the core part; and a lithium-tungsten compound particle that adheres to at least part of a surface of the tungsten-concentrated layer and contains tungsten and lithium. In the battery of the present disclosure, the tungsten-concentrated layer has an amorphous structure. This can bring excellent output characteristics while desired durability is secured.

## Claims

### Claim 1

A nonaqueous electrolyte secondary battery comprising a cathode, an anode, and a nonaqueous electrolyte,
the cathode including a cathode active material layer that contains a granular cathode active material;
the granular cathode active material including:
a core part that contains a lithium-transition metal composite oxide of a layered structure, a mean particle size of the core part is from 0.1 μm to 20 μm;
a tungsten-concentrated layer that is formed over a surface of the core part and has a higher tungsten concentration determined by a TEM-EDX analysis than the core part; and
a lithium-tungsten compound particle that adheres to at least part of a surface of the tungsten-concentrated layer and contains tungsten and lithium, the tungsten-concentrated layer is an amorphous structure, and the lithium-tungsten compound particle has a higher tungsten concentration than the tungsten-concentrated layer, and an atomic concentration of tungsten in the lithium-tungsten compound particle is 90 at % or more based on a total number of transition metal atoms.

### Claim 2 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein an atomic concentration A of tungsten in the tungsten-concentrated layer is 1 at % or more and 3.6 at % or less.

### Claim 3 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein an atomic concentration B of tungsten in the core part is 0.3 at % or less.

### Claim 4 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein the core part comprises Li, Ni, Co, Mn, and O.

### Claim 5 (depends on 1)

The nonaqueous electrolyte secondary battery according to claim 1, wherein a mean particle size of the lithium-tungsten compound particle is from 5 nm to 500 nm.