# US 12,218,354 B2 · Negative-electrode active material and preparation method thereof, secondary battery, and battery module, battery pack, and apparatus containing such secondary battery

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- Number: US 12,218,354 B2
- Document ID: US12218354B2
- Status: Granted
- Kind: B2
- Application number: 17/822,260
- Filed: 2022-08-25
- Published: 2022-12-29
- Granted: 2025-02-04
- Earliest claimed: 2020-10-15
- Assignees: Contemporary Amperex Technology (Hong Kong) Limited
- Applicants: Contemporary Amperex Technology (Hong Kong) Limited
- Inventors: Yuqun Zeng; Baida Deng; Meng Kang; Erling Li; Libing He
- Web page: https://patentgrep.com/patent/US12218354B2

## CPC

- C01B 32/21: After-treatment
- H01M 4/583: Carbonaceous material, e.g. graphite-intercalation compounds or CFx
- C01B 32/205: Preparation
- H01M 4/0404: {by coating on electrode collectors}
- H01M 4/0471: {involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis}
- H01M 4/133: Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/1393: of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/36: Selection of substances as active materials, active masses, active liquids
- H01M 4/364: {as mixtures}
- H01M 4/366: {as layered products}
- H01M 4/587: for inserting or intercalating light metals
- H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M 4/622: {being polymers}
- 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 2004/90: Other morphology not specified above
- C01P 2006/10: Solid density
- C01P 2006/11: Powder tap density
- C01P 2006/12: Surface area
- C01P 2006/40: Electric properties
- H01M 2004/021: {Physical characteristics, e.g. porosity, surface area}
- H01M 2004/027: {Negative electrodes}
- Y02E 60/10: Energy storage using batteries
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

This application discloses a negative-electrode active material and a preparation method thereof, a secondary battery, and a battery module, a battery pack, and an apparatus that include such secondary battery. The negative-electrode active material includes a core and a coating layer covering at least part of a surface of the core, where the core includes artificial graphite, the coating layer includes amorphous carbon, a volume-based particle size distribution of the negative-electrode active material satisfies Dv99≤24 μm, a volume-based median particle size Dv50 of the negative-electrode active material satisfies 8 μm≤Dv≤15 μm, Dv99 is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 99%, and WO is a particle size corresponding to a cumulative volume distribution percentage of the negative-electrode active material reaching 50%.

## Claims

### Claim 1

A preparation method for a negative-electrode active material, comprising:
preparing a core material, wherein the core material comprises granulated artificial graphite;
mixing the core material with an organic carbon source; and
heat treating the mixed core material at 700-1800° C., to form the negative-electrode active material having an amorphous carbon coating layer covering at least part of surfaces of the core material, wherein a graphitization degree of the negative-electrode active material is 91.0%-96.0%;
wherein the granulated artificial graphite is prepared by a process that comprises:
pulverizing a coke raw material;
shaping the pulverized coke raw material to obtain a precursor;
granulating the precursor to obtain a granulated product, wherein the granulated product comprises primary particles and secondary particles, and the secondary particles are obtained by agglomerating independently dispersed primary particles; and
graphitizing the granulated product at a temperature of 2800° C. to 3200° C., to obtain the granulated artificial graphite,
wherein, after pulverization, a volume-based median particle size Dv50 of the coke raw material is 7 μm-12 μm, and a volume-based particle size distribution Dv99 of the coke raw material is 15 μm-21 μm;
wherein, after the shaping, a volume-based median particle size Dv50 of the precursor is 8 μm-13 μm, a volume-based particle size distribution Dv99 of the precursor is 16 μm-22 μm, and a particle size uniformity of the precursor U1 satisfies 0.2≤U1≤0.55;
wherein a volume-based median particle size Dv50 of the granulated product is 9 μm-15 μm, and a volume-based particle size distribution Dv99 of the granulated product is 17 μm-24 μm;
wherein a volume-based median particle size Dv50 of the granulated artificial graphite is 6 μm-14 μm, a volume-based particle size distribution Dv99 of the granulated artificial graphite is 17 μm-26 μm, and a particle size uniformity of the granulated artificial graphite U2 satisfies 0.22≤U2≤0.48; and
wherein a particle size specific surface area of the negative-electrode active material is 0.4 m2/g-0.75 m2/g.

### Claim 2 (depends on 1)

The preparation method according to claim 1, wherein
a volume-based median particle size Dv50 of the negative-electrode active material is 8 μm-15 μm, and
a volume-based particle size distribution Dv99 of the negative-electrode active material is ≤24 μm, and
a particle size uniformity of the negative-electrode active material is 0.25-0.45.

### Claim 3 (depends on 1)

The preparation method according to claim 1, wherein the coke raw material contains an amount C1 of volatile substances, and 1 wt %≤C1≤12 wt % of the coke raw material;
wherein a binder is added to the precursor during granulating the precursor, an amount of the binder added to the precursor in weight percentage of the precursor is C2, and C1, C2 and U1 satisfy:
21≤(C1+C2)/U1≤50.

### Claim 4 (depends on 1)

The preparation method according to claim 1, wherein the coke raw material comprises one or more of petroleum-based non-needle coke, petroleum-based needle coke, and petroleum green coke.

### Claim 5 (depends on 1)

The preparation method according to claim 1, wherein a binder is added to the precursor during granulating the precursor, and the preparation method satisfies the following condition:
20≤(C1+C2+C3)/U2≤56
wherein
C1 is a weight percentage of volatile substances in the coke raw material,
C2 is an amount of the binder added to the precursor in weight percentage of the precursor, and
C3 is an amount of the organic carbon source mixed to the core material in weight percentage of the granulated artificial graphite.

### Claim 6 (depends on 2)

The preparation method according to claim 2, wherein
the volume-based median particle size Dv50 of the negative-electrode active material is 9 μm-13 μm, and
the volume-based particle size distribution Dv99 of the negative-electrode active material is 17 μm-24 μm.