# US 12,113,194 B2 · Method of producing negative electrode

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- Number: US 12,113,194 B2
- Document ID: US12113194B2
- Status: Granted
- Kind: B2
- Application number: 17/610,096
- Filed: 2020-05-07
- Published: 2022-07-14
- Granted: 2024-10-08
- Earliest claimed: 2019-05-10
- Assignees: LG Energy Solution, Ltd.
- Applicants: LG Energy Solution, Ltd.
- Inventors: Oh Byong Chae; Ye Ri Kim
- Web page: https://patentgrep.com/patent/US12113194B2

## CPC

- H01M 4/0459: {Electrochemical doping, intercalation, occlusion or alloying}
- H01M 4/0416: {involving impregnation with a solution, dispersion, paste or dry powder (H01M4/0438 takes precedence)}
- H01M 4/1393: of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
- H01M 4/1395: of electrodes based on metals, Si or alloys
- H01M 4/386: {Silicon or alloys based on silicon}
- H01M 4/587: for inserting or intercalating light metals
- H01M 10/0525: Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
- H01M 10/052: Li-accumulators
- 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 method of producing a negative electrode, which includes: providing a negative electrode roll on which a negative electrode structure is wound, the negative electrode structure includes a negative electrode current collector and a negative electrode active material layer on at least one surface of the negative electrode current collector; providing a pre-lithiation bath containing a pre-lithiation solution, which is sequentially divided into an impregnation section, a pre-lithiation section, and an aging section; impregnating the negative electrode structure with the pre-lithiation solution while unwinding the negative electrode structure from the negative electrode roll and moving the same through the sections. The pre-lithiation is performed by disposing a lithium metal counter electrode, which is spaced apart from the negative electrode structure and impregnated with the pre-lithiation solution, in the pre-lithiation section and electrochemically charging the negative electrode structure.

## Claims

### Claim 1

A method of producing a negative electrode, comprising:
providing a negative electrode roll on which a negative electrode structure is wound, the negative electrode structure comprises a negative electrode current collector and a negative electrode active material layer on at least one surface of the negative electrode current collector;
providing a pre-lithiation bath comprising a pre-lithiation solution, which is sequentially divided into an impregnation section, a pre-lithiation section, and an aging section;
impregnating the negative electrode structure with the pre-lithiation solution while unwinding the negative electrode structure from the negative electrode roll and moving the negative electrode structure through the impregnation section;
pre-lithiating the negative electrode structure having passed through the impregnation section while moving the negative electrode structure through the pre-lithiation section; and
aging the negative electrode structure having passed through the pre-lithiation section while moving the negative electrode structure through the aging section,
wherein the pre-lithiation is performed by disposing a lithium metal counter electrode, which is spaced apart from the negative electrode structure and impregnated with the pre-lithiation solution, in the pre-lithiation section and electrochemically charging the negative electrode structure,
wherein the electrochemically charging is performed by an oxidation-reduction reaction using an electrochemical charging/discharging device,
wherein a time for the negative electrode structure to move through the impregnation section is 1 times to 10 times a time for the negative electrode structure to move through the pre-lithiation section,
wherein a time for the negative electrode structure to move through the aging section is 0.5 times to 21 times a time for the negative electrode structure to move through the pre-lithiation section,
wherein a ratio of lengths of the impregnation section, the pre-lithiation section, and the aging section ranges from 1 to 10:1:0.5 to 21,
wherein the negative electrode active material layer comprises a negative electrode active material, and the negative electrode active material comprises a carbon-based active material and a silicon-based active material in a weight ratio of 60:40 to 95:5, and
the negative electrode structure is moved directly from the impregnation section to the pre-lithiation section in the pre-lithiation solution, and then the negative electrode structure is moved directly from the pre-lithiation section to the aging section in the pre-lithiation solution.

### Claim 2 (depends on 1)

The method of claim 1, wherein a time for the negative electrode structure to move through the pre-lithiation section ranges from 5 minutes to 120 minutes.

### Claim 3 (depends on 1)

The method of claim 1, wherein a temperature of the pre-lithiation bath ranges from 10° C. to 80° C.

### Claim 4 (depends on 1)

The method of claim 1, further comprising washing the aged negative electrode structure by removing the aged negative electrode structure from the pre-lithiation bath, introducing the negative electrode structure into a washing bath comprising an organic solvent, and moving the negative electrode structure through the washing bath.

### Claim 5 (depends on 4)

The method of claim 4, wherein a time for the aged negative electrode structure to move through the washing bath is 0.1 times to 5 times a time for the negative electrode structure to move through the pre-lithiation section.

### Claim 6 (depends on 4)

The method of claim 4, further comprising drying the washed negative electrode structure.

### Claim 7 (depends on 6)

The method of claim 6, wherein a time to dry the washed negative electrode structure is 0.1 times to 5 times a time for the negative electrode structure to move through the pre-lithiation section.

### Claim 8 (depends on 1)

The method of claim 1, wherein a time for the negative electrode structure to move through the aging section is 1.5 times to 11 times a time for the negative electrode structure to move through the pre-lithiation section, and wherein a ratio of lengths of the impregnation section, the pre-lithiation section, and the aging section ranges from 1 to 10:1:1.5 to 11.