# US 10,770,720 B2 · Composite negative electrode material and method for preparing composite negative electrode material, negative electrode plate of lithium ion secondary battery, and lithium ion secondary battery

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- Number: US 10,770,720 B2
- Document ID: US10770720B2
- Status: Granted
- Kind: B2
- Application number: 15/339,081
- Filed: 2016-10-31
- Published: 2017-02-16
- Granted: 2020-09-08
- Earliest claimed: 2014-04-29
- Assignees: Huawei Technologies Co., Ltd.
- Applicants: Huawei Technologies Co., Ltd.
- Inventors: Shengan Xia; Hui Li; Fengchao Xie
- Web page: https://patentgrep.com/patent/US10770720B2

## CPC

- H01M 4/366: {as layered products}
- 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 4/587: for inserting or intercalating light metals
- H01M 4/62: Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- 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
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

A composite negative electrode material, a method for preparing the composite negative electrode material, a negative electrode plate of a lithium ion secondary battery containing the composite negative electrode material, and a lithium ion secondary battery containing a negative electrode active material of the lithium ion secondary battery, where the composite negative electrode material includes a carbon core and a carbon coating layer, where the carbon coating layer is a carbon layer that coats a surface of the carbon core, and both the carbon core and the carbon coating layer include a doping element, where the doping element is at least one of element N, P, B, S, O, F, Cl, or H.

## Claims

### Claim 1

A composite negative electrode, comprising:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is P, B, S, O, F, Cl, or H, and wherein the first doping element is different from the second doping element.

### Claim 2 (depends on 1)

The composite negative electrode of claim 1, wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

### Claim 3 (depends on 1)

The composite negative electrode of claim 1, wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

### Claim 4 (depends on 1)

The composite negative electrode of claim 1, wherein the doped carbon core comprises natural graphite.

### Claim 5 (depends on 1)

The composite negative electrode of claim 1, wherein the second doping element is not S.

### Claim 6 (depends on 5)

The composite negative electrode of claim 5, wherein a specific capacity of the doped carbon core is greater than 372 milliamperehours/gram (mAh/g).

### Claim 7 (depends on 6)

The composite negative electrode of claim 6, wherein the specific capacity of the doped carbon core is 420-620 mAh/g.

### Claim 8

A negative electrode plate of a lithium ion secondary battery, comprising:
a current collector; and
a composite negative electrode that covers the current collector, wherein the composite negative electrode comprises:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is N, P, B, S, F, Cl, or H, and wherein the first doping element of the carbon core is different from the second doping element.

### Claim 9 (depends on 8)

The negative electrode plate of claim 8, wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

### Claim 10 (depends on 8)

The negative electrode plate of claim 8, wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

### Claim 11 (depends on 8)

The negative electrode plate of claim 8, wherein the doped carbon core comprises natural graphite.

### Claim 12 (depends on 8)

The negative electrode plate of the lithium ion secondary battery of claim 8, wherein the second doping element is not S.

### Claim 13 (depends on 12)

The negative electrode plate of the lithium ion secondary battery of claim 12, wherein a specific capacity of the doped carbon core is greater than 372 milliamperehours/gram (mAh/g).

### Claim 14 (depends on 13)

The negative electrode plate of the lithium ion secondary battery of claim 13, wherein the specific capacity of the doped carbon core is 420-620 mAh/g.

### Claim 15

A lithium ion secondary battery, comprising:
a negative electrode plate of the lithium ion secondary battery that comprises:
a current collector; and
a composite negative electrode that covers the current collector, wherein the composite negative electrode comprises:
a doped carbon core containing a first doping element, wherein the first doping element comprises nitrogen, wherein a nitrogen atom of the first doping element and a carbon atom in the doped carbon core are bonded in at least one form of pyridinic nitrogen, graphite nitrogen or pyrrolic nitrogen; and
a doped carbon coating layer that coats a surface of the doped carbon core, wherein the doped carbon coating layer comprises a second doping element that is N, P, B, S, O, F, Cl, or H, and wherein the first doping element is different from the second doping element;
a positive electrode;
a separator separating the negative electrode plate and positive electrode from each other;
a non-aqueous electrolyte; and
a shell that houses the negative electrode plate, the positive electrode, the separator, and the non-aqueous electrolyte to form the lithium ion secondary battery.

### Claim 16 (depends on 15)

The lithium ion secondary battery of claim 15, wherein a mass of the doped carbon coating layer is 5% to 30% of a total mass of the doped carbon coating layer and the doped carbon core.

### Claim 17 (depends on 15)

The lithium ion secondary battery of claim 15, wherein a mass content of the first doping element and the second doping element in the composite negative electrode is 0.1% to 50%.

### Claim 18 (depends on 15)

The lithium ion secondary battery of claim 15, wherein the doped carbon core comprises natural graphite.

### Claim 19 (depends on 15)

The lithium ion secondary battery of claim 15, wherein the second doping element is not S.

### Claim 20 (depends on 19)

The lithium ion secondary battery of claim 19, wherein a specific capacity of the doped carbon core is 420-620 milliamperehours/gram (mAh/g).