# US 12,224,442 B2 · Graphite composite negative electrode material, preparation method therefor and application thereof

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- Number: US 12,224,442 B2
- Document ID: US12224442B2
- Status: Granted
- Kind: B2
- Application number: 18/724,125
- Filed: 2022-07-20
- Published: 2024-12-19
- Granted: 2025-02-11
- Earliest claimed: 2021-12-28
- Assignees: Svolt Energy Technology Co., Ltd.
- Applicants: Svolt Energy Technology Co., Ltd.
- Inventors: Xiaofeng Zhao; Jing Liu; Hongxin Yang
- Web page: https://patentgrep.com/patent/US12224442B2

## CPC

- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/587: for inserting or intercalating light metals
- C01B 32/205: Preparation
- C01B 32/21: After-treatment
- H01M 4/0419: {involving spraying}
- H01M 4/0421: {involving vapour deposition}
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/366: {as layered products}
- 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 4/625: {Carbon or graphite}
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer
- C01P 2006/11: Powder tap density
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- 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
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}
- C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A graphite composite negative electrode material, a preparation method therefor and an application thereof. A coating layer formed by mixing a plurality of substances is coated on the surface of graphite, the high theoretical specific capacity of titanium niobate is utilized, and carbon nanotubes and amorphous carbon are added in an auxiliary manner, the carbon nanotubes form a network structure, and the amorphous carbon stabilizes the structure of the material, which jointly improve the structural stability of the material in the charging and discharging process, and improve the first efficiency and the cycle performance of the material.

## Claims

### Claim 1

A graphite composite negative electrode material, the graphite composite negative electrode material comprises a core and a coating layer which is coated on the surface of the core, the core comprises graphite material, and the coating layer comprises titanium niobate, carbon nanotubes, and amorphous carbon; and
the graphite composite negative electrode material is prepared by the following methods, which comprises:
(1) mixing a titanium source, a niobium source, an asphalt and a solvent, spray drying and sintering to obtain a pre-coating material;
(2) mixing the pre-coating material in step (1) with a solution of a metal catalyst to obtain a mixture, and compositing a carbon source with the mixture in a manner of vapor deposition to obtain a coating layer material; and
(3) mixing the coating layer material in step (2) with a graphite material, granulating, and carbonizing to obtain the graphite composite negative electrode material.

### Claim 2 (depends on 1)

The graphite composite negative electrode material of claim 1, wherein based on 100% of the mass of the graphite composite negative electrode material, a ratio of the mass of the coating layer is in a range from 1% to 10%; based on 100% of the mass of the coating layer, a ratio of the mass of the titanium niobate is in a range from 10% to 50%; and based on 100% of the mass of the coating layer, a ratio of the mass of the carbon nanotube is in a range from 1% to 5%.

### Claim 3 (depends on 1)

The graphite composite negative electrode material of claim 1, wherein the chemical formula of the titanium niobate is Ti1-xNbxO7, 0<x<1.

### Claim 4 (depends on 1)

The graphite composite negative electrode material of claim 1, wherein a specific surface area of the graphite composite negative electrode material is in a range from 0.5 m2/g to 10 m2/g, a median particle size of the graphite composite negative electrode material is in a range from 5 μm to 20 μm, and a tap density of the graphite composite negative electrode material is in a range from 0.6 g/cm3 to 1.4 g/cm3.

### Claim 5 (depends on 4)

The graphite composite negative electrode material of claim 4, wherein the specific surface area of the graphite composite negative electrode material is in a range from 1 m2/g to 5 m2/g, the median particle size of the graphite composite negative electrode material is in a range from 9 μm to 15 μm, and the tap density of the graphite composite negative electrode material is in a range from 0.9 g/cm3 to 1.2 g/cm3.

### Claim 6 (depends on 1)

A method for preparing the graphite composite negative electrode material of claim 1, comprising the following steps:
(1) mixing a titanium source, a niobium source, an asphalt and a solvent, spray drying and sintering to obtain a pre-coating material;
(2) mixing the pre-coating material in step (1) with a solution of a metal catalyst to obtain a mixture, and compositing a carbon source with the mixture in a manner of vapor deposition to obtain a coating layer material; and
(3) mixing the coating layer material in step (2) with a graphite material, granulating, and carbonizing to obtain the graphite composite negative electrode material.

### Claim 7 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the titanium source in step (1) comprises titanium dioxide; the niobium source in step (1) comprises any one or a combination of at least two of niobium pentoxide, niobium trioxide, niobium oxide, and niobium hydroxide; the solvent in step (1) comprises any one or a combination of at least two of carbon tetrachloride, n-hexane, xylene, N-methylpyrrolidone and tetrahydrofuran; and a mass ratio of the titanium source, the niobium source, and the asphalt in step (1) is (1-5):(10-50):100.

### Claim 8 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the sintering in step (1) is carried out at a temperature ranging from 600° C. to 1000° C. for a time period ranging from 1 hour to 6 hours.

### Claim 9 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the median particle size of the metal catalyst in step (2) is in a range from 10 nm to 500 nm; the metal catalyst in step (2) comprises any one or a combination of at least two of nano-iron, nano-nickel, and nano-cobalt; in step (2), the mass ratio of the pre-coating material to the metal catalyst is 100:(0.5-2); the mixing in step (2) is carried out for a time period ranging from 1 hour to 24 hours; and wherein the mixed substances in step (2) are subsequently filtered and dried in a vacuum to obtain a mixture.

### Claim 10 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the vapor deposition in step (2) is carried out at a temperature ranging from 600° C. to 1000° C. for a time period ranging from 1 hour to 12 hours, and the carbon source for vapor deposition in step (2) includes any one or a combination of at least two of methane, ethane, ethylene, acetylene, propane, and propylene.

### Claim 11 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein in step (3), a mass ratio of the coating layer material to the graphite material is (1-10):100.

### Claim 12 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the mixing in step (3) is carried out for a time period ranging from 30 minutes to 120 minutes.

### Claim 13 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the granulating in step (3) is carried out at a temperature ranging from 600° C. to 800° C. for a time period ranging from 1 hour to 6 hours.

### Claim 14 (depends on 6)

The method for preparing the graphite composite negative electrode material of claim 6, wherein the method for preparing the graphite composite negative electrode material comprises the following steps:
(1) mixing a titanium source, a niobium source and an asphalt in a mass ratio of (1-5):(10-50):100 with a solvent, spray drying and sintering at 600° C. to 1000° C. for 1 hour to 6 hours to obtain a pre-coating material;
(2) mixing the pre-coating material in step (1) with a solution of a metal catalyst with a median particle size of 10 nm to 500 nm in a mass ratio of the pre-coating material to the metal catalyst of 100:(0.5-2) for 1 hour to 24 hours to obtain a mixture, and compositing a carbon source with the mixture at 600° C. to 1000° C. for 1 hour to 12 hours in a manner of a vapor deposition to obtain a coating layer material; and
(3) mixing the coating layer material in step (2) with a graphite material in a mass ratio of (1-10):100 for 30 minutes to 120 minutes, granulating at 600° C. to 800° C. for 1 hour to 6 hours, and carbonizing at a carbonizing temperature of 1000° C. to 1300° C. for 6 hours to 24 hours to obtain the graphite composite negative electrode material.

### Claim 15 (depends on 1)

A lithium-ion battery, comprising the graphite composite negative electrode material of claim 1.

### Claim 16 (depends on 13)

The graphite composite negative electrode material of claim 13, wherein the carbonizing in step (3) is carried out at a temperature ranging from 1000° C. to 1300° C. for a time period ranging from 6 hours to 24 hours.