# US 12,110,231 B2 · Expanded graphite and preparation method therefor

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- Number: US 12,110,231 B2
- Document ID: US12110231B2
- Status: Granted
- Kind: B2
- Application number: 18/289,488
- Filed: 2022-08-31
- Published: 2024-07-18
- Granted: 2024-10-08
- Earliest claimed: 2021-12-16
- Assignees: Guangdong Brunp Recycling Technology Co., Ltd.; Hunan Brunp Recycling Technology Co., Ltd.; Yichang Brunp Recycling Technology Co., Ltd.
- Applicants: Guangdong Brunp Recycling Technology Co., Ltd.; Hunan Brunp Recycling Technology Co., Ltd.; Yichang Brunp Recycling Technology Co., Ltd.
- Inventors: Linshao Zhang; Changdong Li; Dingshan Ruan; You Zhou; Qiang Li; Yong Cai
- Web page: https://patentgrep.com/patent/US12110231B2

## CPC

- C01B 32/225: Expansion; Exfoliation
- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- C01P 2004/03: obtained by SEM
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/54: Reclaiming serviceable parts of waste accumulators
- Y02W 30/84: Recycling of batteries or fuel cells
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02W: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT

## Abstract

A preparation method comprises the following steps: (1) in a protective atmosphere, mixing a graphite powder with a metal peroxide and/or alkali metal superoxide, and leaving same to stand to obtain a mixed graphite-metal peroxide and/or graphite-alkali metal superoxide composite material; (2) putting the composite material prepared in step (1) into a liquid medium, which can react with the metal peroxide and/or the alkali metal superoxide, for a reaction to obtain intercalated graphite; and (3) heating the intercalated graphite prepared in step (2) to prepare the expanded graphite. The preparation method can effectively avoid the generation of harmful impurities such as sulfur and sulfides during the preparation process of the expanded graphite, thereby reducing environmental pollution.

## Claims

### Claim 1

A preparation method for an expanded graphite, comprising the following steps:
(1) mixing a graphite powder with a metal peroxide and/or an alkali metal superoxide under a protective atmosphere, and leaving the mixture to stand still, to obtain a mixed graphite-metal peroxide and/or graphite-alkali metal superoxide composite material;
(2) putting the composite material prepared in step (1) into a liquid medium capable of reacting with the metal peroxide and/or the alkali metal superoxide for reacting, to obtain an intercalated graphite; and
(3) heating the intercalated graphite prepared in step (2) to prepare the expanded graphite,
wherein the metal peroxide is at least one of CaO2, K2O2, Na2O2 and Li2O2;
the alkali metal superoxide is at least one of KO2 and NaO2; and
a mass ratio of the graphite powder to the metal peroxide and/or the alkali metal superoxide in step (1) is (1 to 20):1.

### Claim 2 (depends on 1)

The preparation method for the expanded graphite according to claim 1, characterized in that, a time for leaving the mixture to stand still in step (1) is 12 hours to 24 hours.

### Claim 3 (depends on 1)

The preparation method for the expanded graphite according to claim 1, characterized in that, a temperature for the heating in step (3) is 1,000° C. to 1,500° C., and a time for the heating is 15 seconds to 30 seconds.

### Claim 4 (depends on 1)

The preparation method for the expanded graphite according to claim 1, characterized in that, the liquid medium is at least one of water, formic acid, acetic acid, propionic acid, hydrochloric acid, carbonic acid, citric acid, hydrofluoric acid, malic acid, gluconic acid, lactic acid, benzoic acid, acrylic acid, stearic acid, hydrosulphuric acid, hypochlorous acid and boric acid.

### Claim 5 (depends on 1)

The preparation method for the expanded graphite according to claim 1, characterized in that, a particle size of the graphite powder ranges from 80 meshes to 100 meshes.

### Claim 6 (depends on 1)

The preparation method for the expanded graphite according to claim 1, characterized in that, the graphite powder is obtained by washing, drying and sieving the leached residue of a waste lithium ion battery.

### Claim 7 (depends on 2)

The preparation method for the expanded graphite according to claim 2, characterized in that, the graphite powder is obtained by washing, drying and sieving the leached residue of a waste lithium ion battery.

### Claim 8 (depends on 3)

The preparation method for the expanded graphite according to claim 3, characterized in that, the graphite powder is obtained by washing, drying and sieving the leached residue of a waste lithium ion battery.

### Claim 9 (depends on 4)

The preparation method for the expanded graphite according to claim 4, characterized in that, the graphite powder is obtained by washing, drying and sieving the leached residue of a waste lithium ion battery.

### Claim 10 (depends on 5)

The preparation method for the expanded graphite according to claim 5, characterized in that, the graphite powder is obtained by washing, drying and sieving the leached residue of a waste lithium ion battery.