Anode for lithium secondary battery and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-11929495-B2
Application number	US-202318319931-A
Country	US
Kind code	B2
Filing date	May 18, 2023
Priority date	May 18, 2022
Publication date	Mar 12, 2024
Grant date	Mar 12, 2024

Abstract

In some implementations, the anode includes a current collector, a first anode mixture layer formed on at least one surface of the current collector, and a second anode mixture layer formed on the first anode mixture layer. The first anode mixture layer and the second anode mixture layer include a carbon-based active material, respectively. The first anode mixture layer includes a first binder, a first silicon-based active material, and a first conductive material. The second anode mixture layer includes a second binder, a second silicon-based active material, and a second conductive material. Contents of the first conductive material and the second conductive material are different from each other with respect to the total combined weight of the first anode mixture layer and the second anode mixture layer. Types of the first silicon-based active material and the second silicon-based active material are different from each other.

First claim

What is claimed is:

1. An anode for a lithium-ion secondary battery, the anode comprising:
a current collector;
a first anode mixture layer formed on at least one surface of the current collector; and
a second anode mixture layer formed on the first anode mixture layer,
wherein the first anode mixture layer and the second anode mixture layer include a carbon-based active material, respectively,
the first anode mixture layer includes a first binder, a first silicon-based active material, and a first conductive material,
the second anode mixture layer includes a second binder, a second silicon-based active material, and a second conductive material,
contents of the first conductive material and the second conductive material are different from each other with respect to the total combined weight of the first anode mixture layer and the second anode mixture layer,
types of the first silicon-based active material and the second silicon-based active material are different from each other, and
the first silicon-based active material includes a silicon oxide-based active material, and
the second silicon-based active material includes a Si—C composite.

2. The anode of claim 1 , wherein types of the first binder and the second binder are different from each other.

3. The anode of claim 2 , wherein the second binder includes at least one of a polyacrylic acid (PAA)-based binder, a polyvinyl alcohol (PVA)-based binder, and a polyvinyl alcohol-polyacrylic acid (PVA-PAA) copolymer-based binder.

4. The anode of claim 3 , wherein a content of a polyacrylic acid monomer in the polyacrylic acid (PAA)-based binder, a content of a polyvinyl alcohol monomer in the polyvinyl alcohol (PVA)-based binder, or a content of a polyvinyl alcohol-polyacrylic acid copolymer monomer in the polyvinyl alcohol-polyacrylic acid (PVA-PAA) copolymer binder is 10 to 90 mol % with respect to the total content of each monomer.

5. The anode of claim 1 , wherein a content of the first conductive material is greater than a content of the second conductive material with respect to the total combined weight of the first anode mixture layer and the second anode mixture layer.

6. The anode of claim 1 , wherein a content of the second silicon-based active material is greater than a content of the first silicon-based active material with respect to the total combined weight of the first anode mixture layer and the second anode mixture layer.

7. The anode of claim 6 , wherein a content ratio between the first silicon-based active material and the second silicon-based active material is 1:9 to 4:6 with respect to the total combined weight of the first anode mixture layer and the second anode mixture layer.

8. The anode of claim 1 , wherein the first binder includes styrene-butadiene rubber (SBR).

9. The anode of claim 8 , wherein a content of a butadiene monomer in the styrene-butadiene rubber (SBR) is 50 to 95 mol % with respect to the total content of the monomers.

10. The anode of claim 1 , wherein types of the first conductive material and the second conductive material are different from each other.

11. The anode of claim 1 , wherein
a Raman R value is represented by Equation 1 below,
a Raman R value of the first conductive material is greater than or equal to a Raman R value of the second conductive material, and
Raman R=I D /I G   [Equation 1]

In Equation 1, I D represents a peak intensity value in an absorption region of 1350 to 1380 cm −1 , and I G represents a peak intensity value in an absorption region of 1580 to 1600 cm −1 .

12. The anode of claim 11 , wherein
the Raman R value of the first conductive material is 0.1 to 1.8, and
the Raman R value of the second conductive material is 0.01 to 0.1.

13. The anode of claim 1 , wherein a loading weight (LW) ratio between the first anode mixture layer and the second anode mixture layer is 2:8 to 5:5.

14. The anode of claim 1 , wherein an adhesive force between the current collector and the first anode mixture layer is 0.45 N/18 mm or more.

15. A lithium-ion secondary battery comprising:
an anode for a secondary battery of claim 1 .

Assignees

• Sk On Co Ltd

Inventors

• Kim Hyo Mi
• Kim Moon Sung
• Ryu Sang Baek
• Park Da Hye
• Yook Seung Hyun
• Jang Hwan Ho
• Jeong Kwang Ho
• Chung Da Bin
• Han Jun Hee

Classifications

• H01M4/366 Primary

  as layered products · CPC title

• H01M4/133 Primary

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

• H01M4/134 Primary

  Electrodes based on metals, Si or alloys · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title