# US 12,218,338 B2 · Electrode, storage battery, power storage device, and electronic device

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- Number: US 12,218,338 B2
- Document ID: US12218338B2
- Status: Granted
- Kind: B2
- Application number: 17/569,537
- Filed: 2022-01-06
- Published: 2022-09-22
- Granted: 2025-02-04
- Earliest claimed: 2015-07-16
- Assignees: Semiconductor Energy Laboratory Co., Ltd.
- Applicants: Semiconductor Energy Laboratory Co., Ltd.
- Inventors: Kiyofumi Ogino
- Web page: https://patentgrep.com/patent/US12218338B2

## CPC

- H01M 4/134: Electrodes based on metals, Si or alloys
- H01G 11/28: arranged or disposed on a current collector; Layers or phases between electrodes and current collectors, e.g. adhesives
- H01G 11/32: Carbon-based
- H01G 11/38: Carbon pastes or blends; Binders or additives therein
- H01G 11/42: Powders or particles, e.g. composition thereof
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/622: {being polymers}
- H01M 4/625: {Carbon or graphite}
- H01G 11/66: Current collectors
- H01G 11/84: Processes for the manufacture of hybrid or EDL capacitors, or components thereof
- H01M 4/1395: of electrodes based on metals, Si or alloys
- 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
- Y02E 60/13: Energy storage using capacitors
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A power storage device with high capacity is provided. A power storage device with high energy density is provided. A highly reliable power storage device is provided. A long-life power storage device is provided. An electrode with high capacity is provided. An electrode with high energy density is provided. A highly reliable electrode is provided. Such a power storage device includes a first electrode and a second electrode. The first electrode includes a first current collector and a first active material layer. The first active material layer includes active material particles, spaces provided on the periphery of the active material particles, graphene, and a binder. The active material particles are silicon. The active material particles and the spaces are surrounded by the graphene and the binder.

## Claims

### Claim 1

A method for manufacturing a negative electrode, the method comprising the steps of:
forming a plurality of silicon particles;
performing a heat treatment on the plurality of silicon particles in an atmosphere containing air to form a silicon oxide film on a surface of each of the plurality of silicon particles;
mixing a graphene compound, a binder, and the plurality of silicon particles after the heat treatment;
performing an etching treatment on the plurality of silicon particles after the heat treatment; and
forming a slurry after the etching treatment,
wherein part of the silicon oxide film on the surface of each of the plurality of silicon particles is removed by the etching treatment,
wherein the part of the silicon oxide film which is removed by the etching treatment forms a space, and
wherein the heat treatment is performed at a temperature higher than or equal to 700° C. and lower than or equal to 1000° C.

### Claim 2 (depends on 1)

The method for manufacturing a negative electrode according to claim 1, wherein the space is present between a first silicon particle of the plurality of silicon particles and a second silicon particle of the plurality of silicon particles.

### Claim 3 (depends on 2)

The method for manufacturing a negative electrode according to claim 2,
wherein the graphene compound is in contact with a first surface of the first silicon particle of the plurality of silicon particles,
wherein the graphene compound is in contact with a first surface of the second silicon particle of the plurality of silicon particles, and
wherein the graphene compound is in contact with a second surface of the second silicon particle of the plurality of silicon particles.

### Claim 4 (depends on 1)

The method for manufacturing a negative electrode according to claim 1, wherein the graphene compound is in contact with the plurality of silicon particles.

### Claim 5 (depends on 1)

The method for manufacturing a negative electrode according to claim 1,
wherein the graphene compound includes 2 or more and 100 or less reduced graphene oxide layers,
wherein a distance between a first reduced graphene oxide layer and a second reduced graphene oxide layer is greater than or equal to 0.335 nm and less than or equal to 0.7 nm, and
wherein an average diameter of the plurality of silicon particles is greater than or equal to 0.5 μm and less than or equal to 1.5 μm.

### Claim 6

A method for manufacturing a negative electrode, the method comprising the steps of:
forming a plurality of active material particles;
performing a heat treatment on the plurality of active material particles in an atmosphere containing air to form an oxide film on a surface of each of the plurality of active material particles;
mixing a graphene compound, a binder, and the plurality of active material particles after the heat treatment;
performing an etching treatment on the plurality of active material particles after the heat treatment; and
forming a slurry after the etching treatment,
wherein part of the oxide film on the surface of each of the plurality of active material particles is removed by the etching treatment,
wherein the part of the oxide film which is removed by the etching treatment forms a space,
wherein a thickness of the oxide film is greater than or equal to 100 nm and less than or equal to 900 nm, and
wherein an aqueous solution containing fluorine is used for the etching treatment.

### Claim 7 (depends on 6)

The method for manufacturing a negative electrode according to claim 6, wherein the space is present between a first active material particle of the plurality of active material particles and a second active material particle of the plurality of active material particles.

### Claim 8 (depends on 7)

The method for manufacturing a negative electrode according to claim 7,
wherein the graphene compound is in contact with a first surface of the first active material particle of the plurality of active material particles,
wherein the graphene compound is in contact with a first surface of the second active material particle of the plurality of active material particles, and
wherein the graphene compound is in contact with a second surface of the second active material particle of the plurality of active material particles.

### Claim 9 (depends on 6)

The method for manufacturing a negative electrode according to claim 6, wherein the graphene compound is in contact with the plurality of active material particles.

### Claim 10 (depends on 6)

The method for manufacturing a negative electrode according to claim 6,
wherein the graphene compound includes 2 or more and 100 or less reduced graphene oxide layers,
wherein a distance between a first reduced graphene oxide layer and a second reduced graphene oxide layer is greater than or equal to 0.335 nm and less than or equal to 0.7 nm, and
wherein an average diameter of the plurality of active material particles is greater than or equal to 0.5 μm and less than or equal to 1.5 μm.

### Claim 11 (depends on 6)

The method for manufacturing a negative electrode according to claim 6, wherein the heat treatment is performed at a temperature higher than or equal to 700° C. and lower than or equal to 1000° C.