# US 2021/0344016 A1 · Negative electrode for nonaqueous electrolyte secondary batteries and battery thereof

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- Number: US 2021/0344016 A1
- Document ID: US20210344016A1
- Status: Published application
- Kind: A1
- Application number: 17/370,125
- Filed: 2021-07-08
- Published: 2021-11-04
- Earliest claimed: 2019-01-08
- Assignees: Kaneka Corporation
- Applicants: Kaneka Corporation
- Inventors: Masato Kuratsu
- Web page: https://patentgrep.com/patent/US20210344016A1

## CPC

- H01M 4/625: {Carbon or graphite}
- 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 4/621: {Binders}
- H01M 4/622: {being polymers}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- B82Y 30/00: Nanotechnology for materials or surface science, e.g. nanocomposites
- H01M 2004/027: {Negative 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
- B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

[Problem] Repeated charge and discharge of a nonaqueous electrolyte secondary battery result in gas generation and thus a reduction in the battery capacity. [Solving Means] The problem can be solved by providing a negative electrode for nonaqueous electrolyte secondary batteries including a negative electrode active material having an average operating potential of 0.5 V (vs. Li/Li+) or more and less than 2.0 V (vs. Li/Li+) during desorption and insertion of lithium ions, a conductive aid that is carbon nanotubes having a diameter of 100 nm or less, and a binder that is macromolecules having acidic functional groups.

## Claims

### Claim 1

A negative electrode for nonaqueous electrolyte secondary batteries, comprising:
a negative electrode active material;
a conductive aid; and
a binder, wherein
the negative electrode active material has an average operating potential of 0.5 V vs. Li/Li+ or more and less than 2.0 V vs. Li/Li+ during desorption and insertion of lithium ions,
the conductive aid contains 0.05 percent by weight or more and 2 percent by weight or less of carbon nanotubes having a diameter of 100 nm or less with respect to the total weight of the negative electrode active material, the conductive aid, and the binder, and
the binder contains 2 percent by weight or more and 8 percent by weight or less of macromolecules having acidic functional groups with respect to the total weight of the negative electrode active material, the conductive aid, and the binder.

### Claim 2 (depends on 1)

The negative electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the conductive aid is carbon nanotubes having a diameter of 50 nm or less.

### Claim 3 (depends on 1)

The negative electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the weight of the macromolecules having the acidic functional groups is 3 times or more and less than 50 times the weight of the carbon nanotubes included in the negative electrode for nonaqueous electrolyte secondary batteries.

### Claim 4 (depends on 1)

The negative electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the negative electrode active material contains at least one of a titanium-containing oxide and a metal-organic compound.

### Claim 5 (depends on 1)

The negative electrode for nonaqueous electrolyte secondary batteries according to claim 1, wherein the macromolecules having the acidic functional groups are polyvinylidene fluoride, polyvinyl pyrrolidone, styrene-butadiene rubber, or polyacrylic acid.

### Claim 6 (depends on 1)

A nonaqueous electrolyte secondary battery using the negative electrode according to claim 1.