# US 2021/0242448 A1 · Battery negative electrode material, method for manufacturing same, negative electrode for secondary battery, and secondary battery

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- Number: US 2021/0242448 A1
- Document ID: US20210242448A1
- Status: Published application
- Kind: A1
- Application number: 17/222,113
- Filed: 2021-04-05
- Published: 2021-08-05
- Earliest claimed: 2018-01-12
- Assignees: Kureha Corporation; Panasonic Corporation
- Applicants: Kureha Corporation; Panasonic Corporation
- Inventors: Makoto IMAJI; Yukitaro SAKAKIBARA; Shota KOBAYASHI; Kenichi HOTEHAMA; Daisuke KATOU; Ryohei MIYAMAE
- Web page: https://patentgrep.com/patent/US20210242448A1

## CPC

- H01M 4/1393: of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/0428: {Chemical vapour deposition}
- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/134: Electrodes based on metals, Si or alloys
- H01M 4/1395: of electrodes based on metals, Si or alloys
- H01M 4/364: {as mixtures}
- H01M 4/366: {as layered products}
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/587: for inserting or intercalating light metals
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- 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 battery negative electrode material exhibiting both a merit of high specific capacity obtained by using Si, and a merit of high cycle durability obtained by using a non-graphitizable carbon material. Specifically, provided is a negative electrode material (1) of a battery that includes silicon material areas (10) made of a silicon material, and a carbon material area (20) made of a carbon material. The carbon material area (20) is formed in a surrounding area of the silicon material area (10), separated by a cavity (30) at least at a portion. In addition, an (002) average interlayer spacing d002 of the carbon material area (20) determined by powder X-ray diffraction is from 0.365 nm to 0.390 nm. The battery negative electrode material 1 is manufactured through: a step (a) of melting and mixing or dissolving and mixing with an organic material composition, a coated silicon material that has been coated with silicon oxide; a step (b) of removing the silicon oxide; and a step (c) of carbonizing an organic material constituting the organic material composition.

## Claims

### Claim 1

A method for manufacturing a battery negative electrode material, the battery negative electrode material being a composite substance comprising silicon material areas of a silicon material, and a carbon material area of a carbon material, formed in a surrounding area of the silicon material areas, separated by cavities at least at a portion;
the method comprising steps (a) to (c):
step (a): mixing an organic material composition and a coated silicon material that is a silicon precursor coated with silicon oxide and obtaining a composite substance of the organic material composition and the coated silicon material;
step (b): removing the silicon oxide from a composite substance resulting from the step (a); and
step (c): carbonizing an organic material constituting the organic material composition by subjecting a composite substance resulting from the step (b) to a main firing at a temperature of 1,000° C. to 1,500° C. in a non-oxidizing gas atmosphere;
wherein an (002) average interlayer spacing d002 of the carbon material area determined by powder X-ray diffraction using CuKα rays is from 0.365 nm to 0.390 nm, and
wherein a maximum particle size of the coated silicon material is 1,000 nm or less.

### Claim 2 (depends on 1)

The method for manufacturing a battery negative electrode material according to claim 1, wherein the step (a) further comprises an infusibilization treatment to the obtained composite substance.

### Claim 3 (depends on 1)

The method for manufacturing a battery negative electrode material according to claim 1, further comprising a step (d): coating a composite substance resulting from the step (c) with a pyrolytic carbon.

### Claim 4 (depends on 1)

The method for manufacturing a battery negative electrode material according to claim 1, wherein the organic material composition comprises at least one selected from the group consisting of petroleum-based pitch, petroleum-based tar, coal-based pitch, and coal-based tar.

### Claim 5 (depends on 1)

The method for manufacturing a battery negative electrode material according to claim 1, wherein the composite substance obtained in the step (a) is a composite substance in which the coated silicon material is dispersed in the organic material composition.

### Claim 6 (depends on 1)

The method for manufacturing a battery negative electrode material according to claim 1, wherein the content amount of the silicon material is 5 mass % or greater and 25 mass % or less relative to 100 mass % of the negative electrode material.