Method of producing negative electrode

Patent metadata

Field	Value
Publication number	US-12113194-B2
Application number	US-202017610096-A
Country	US
Kind code	B2
Filing date	May 7, 2020
Priority date	May 10, 2019
Publication date	Oct 8, 2024
Grant date	Oct 8, 2024

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.

First claim

The invention claimed is:

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.

2. 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.

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

4. 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.

5. 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.

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

7. 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.

8. 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.

Assignees

• Lg Energy Solution Ltd

Inventors

• Chae Oh Byong
• Kim Ye Ri

Classifications

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/1395

  of electrodes based on metals, Si or alloys · CPC title

• H01M4/1393

  of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• H01M4/364

  as mixtures · CPC title