# US 12,113,205 B2 · Negative electrode active material, negative electrode, and secondary battery

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- Number: US 12,113,205 B2
- Document ID: US12113205B2
- Status: Granted
- Kind: B2
- Application number: 17/533,439
- Filed: 2021-11-23
- Published: 2022-03-17
- Granted: 2024-10-08
- Earliest claimed: 2019-06-26
- Assignees: Murata Manufacturing Co., Ltd.
- Applicants: Murata Manufacturing Co., Ltd.
- Inventors: Naoki Hayashi
- Web page: https://patentgrep.com/patent/US12113205B2

## CPC

- H01M 4/364: {as mixtures}
- H01M 10/052: Li-accumulators
- H01M 4/131: Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/366: {as layered products}
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/483: {for non-aqueous cells (H01M4/485 takes precedence)}
- H01M 4/587: for inserting or intercalating light metals
- H01M 4/622: {being polymers}
- H01M 4/624: {Electric conductive fillers}
- 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
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

The negative electrode active material includes a plurality of first negative electrode active material particles. Each of the first negative electrode active material particles includes a central portion including silicon and a covering portion provided on a surface of the central portion. The covering portion includes a (meth)acrylic acid-based polymer and a compound having a siloxane bond. The (meth)acrylic acid-based polymer includes at least one of poly(meth)acrylate or a derivative of poly(meth)acrylic acid.

## Claims

### Claim 1

A negative electrode active material comprising
a plurality of first negative electrode active material particles each including:
a central portion including silicon; and
a covering portion provided on a surface of the central portion, the covering portion including a (meth)acrylic acid-based polymer and a compound having a siloxane bond,
wherein the (meth)acrylic acid-based polymer includes at least one of poly(meth)acrylate or a derivative of poly(meth)acrylic acid.

### Claim 2 (depends on 1)

The negative electrode active material according to claim 1, wherein the plurality of first negative electrode active material particles are substantially in contact with each other to form a composite particle.

### Claim 3 (depends on 1)

The negative electrode active material according to claim 1, wherein
a content of the poly(meth)acrylate in each of the first negative electrode active material particles is from 0.1 mass % to 10 mass %, and
a content of the compound having a siloxane bond in each of the first negative electrode active material particles is from 0.1 mass % to 10 mass %.

### Claim 4 (depends on 2)

The negative electrode active material according to claim 2, wherein
a content of the poly(meth)acrylate in each of the first negative electrode active material particles is from 0.1 mass % to 10 mass %, and
a content of the compound having a siloxane bond in each of the first negative electrode active material particles is from 0.1 mass % to 10 mass %.

### Claim 5 (depends on 1)

The negative electrode active material according to claim 1, wherein the covering portion further includes a conductive material.

### Claim 6 (depends on 2)

The negative electrode active material according to claim 2, wherein the covering portion further includes a conductive material.

### Claim 7 (depends on 3)

The negative electrode active material according to claim 3, wherein the covering portion further includes a conductive material.

### Claim 8 (depends on 4)

The negative electrode active material according to claim 4, wherein the covering portion further includes a conductive material.

### Claim 9 (depends on 5)

The negative electrode active material according to claim 5, wherein a content of the conductive material in each of the first negative electrode active material particles is from 0.001 mass % to 10 mass %.

### Claim 10 (depends on 1)

The negative electrode active material according to claim 1, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 11 (depends on 2)

The negative electrode active material according to claim 2, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 12 (depends on 3)

The negative electrode active material according to claim 3, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 13 (depends on 4)

The negative electrode active material according to claim 4, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 14 (depends on 5)

The negative electrode active material according to claim 5, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 15 (depends on 9)

The negative electrode active material according to claim 9, further comprising a plurality of second negative electrode active material particles each including a carbon material.

### Claim 16 (depends on 1)

A negative electrode comprising the negative electrode active material according to claim 1.

### Claim 17 (depends on 1)

A secondary battery comprising:
a positive electrode;
a negative electrode; and
an electrolyte,
wherein the negative electrode includes the negative electrode active material according to claim 1.