Anode including material layers with different ID/IG ratios, lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-12040490-B2
Application number	US-202117357254-A
Country	US
Kind code	B2
Filing date	Jun 24, 2021
Priority date	Jun 26, 2020
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

An anode for a lithium secondary battery includes an anode current collector, and an anode active material layer disposed on the anode current collector. The anode active material layer includes a first anode active material layer including a first anode active material and a first binder that includes an acrylate-styrene butadiene copolymer, and a second anode active material layer disposed on the first anode material layer, the second anode active material layer including a second anode active material and a second binder that includes an acrylate-styrene-butadiene copolymer. A peak intensity ratio according to Raman spectroscopy of the first anode active material is smaller than the peak intensity ratio according to Raman spectroscopy of the second anode active material, and the peak intensity ratio according to Raman spectroscopy is represented as I D /I G .

First claim

What is claimed is:

1. An anode for a lithium secondary battery, comprising:
an anode current collector;
an anode active material layer disposed on the anode current collector, wherein the anode active material layer comprises:
a first anode active material layer disposed between the anode current collector and a second anode active material layer, the first anode active material layer including a first anode active material and a first binder that includes a first acrylate-styrene butadiene copolymer; and
the second anode active material layer directly disposed on the first anode active material layer, the second anode active material layer including a second anode active material and a second binder that includes a second acrylate-styrene butadiene copolymer,
wherein a peak intensity ratio according to Raman spectroscopy of the first anode active material is smaller than the peak intensity ratio according to Raman spectroscopy of the second anode active material, and the peak intensity ratio according to Raman spectroscopy is represented as I D /I G ,
wherein a first peak intensity ratio measured by X-ray diffraction of the first anode active material is in a range from 0.001 to 0.012,
the first peak intensity ratio measured by X-ray diffraction of the second anode active material is in a range from 0.013 to 0.05, and
the first peak intensity ratio measured by X-ray diffraction is represented as I(110)/I(002) obtained in an X-ray diffraction analysis, wherein a second peak intensity ratio measured by X-ray diffraction of the first anode active material is in a range from 0.1 to 0.35,
the second peak intensity ratio measured by X-ray diffraction of the second anode active material is in a range from 0.4 to 1.0, and
the second peak intensity ratio measured by X-ray diffraction is represented as I(110)/I(004) obtained in the X-ray diffraction analysis.

2. The anode for a lithium secondary battery according to claim 1 , wherein a thickness of the second anode active material layer is from 3% to 70% of a total thickness of the anode active material layer.

3. The anode for a lithium secondary battery according to claim 1 , wherein the peak intensity ratio according to Raman spectroscopy of the first anode active material is in a range from 0.1 to 0.4.

4. The anode for a lithium secondary battery according to claim 1 , wherein the peak intensity ratio according to Raman spectroscopy of the second anode active material is in a range from 0.4 to 1.5.

5. The anode for a lithium secondary battery according to claim 1 , wherein a ratio of the peak intensity ratio according to Raman spectroscopy of the second anode active material relative to the peak intensity ratio according to Raman spectroscopy of the first anode active material is in a range from 1.5 to 5.

6. The anode for a lithium secondary battery according to claim 1 , wherein a ratio of the content of the repeating units derived from the acrylate monomer in the second acrylate-styrene butadiene copolymer of the second binder relative to the content of the repeating units derived from the acrylate monomer in the first acrylate-styrene butadiene copolymer of the first binder is greater than 1, and equal to or less than 10.

7. The anode for a lithium secondary battery according to claim 1 , wherein a content of the first binder is 1.5 wt % or less based on a total weight of the first anode active material layer.

8. The anode for a lithium secondary battery according to claim 1 , wherein a content of the second binder is from 1 wt % to 3 wt % based on a total weight of the second anode active material layer.

9. The anode for a lithium secondary battery according to claim 1 , wherein a content of repeating units derived from an acrylate monomer in the first acrylate-styrene butadiene copolymer of the first binder is smaller than a content of repeating units derived from an acrylate monomer in the second acrylate-styrene butadiene copolymer of the second binder.

10. The anode for a lithium secondary battery according to claim 9 , wherein the content of the repeating units derived from the acrylate monomer in the first acrylate-styrene butadiene copolymer is from 5 wt % to 30 wt % in the first binder, and the content of the repeating units derived from the acrylate monomer in the second acrylate-styrene butadiene copolymer is from 45 wt % to 90 wt % in the second binder.

11. A lithium secondary battery, comprising:
the anode for a lithium secondary battery according to claim 1 ; and
a cathode facing the anode.

Assignees

• Sk On Co Ltd

Inventors

• Kim Hyo Mi
• Jeong Kwang Ho
• Chung Da Bin
• Hwang Hae Suk

Classifications

• H01M10/0525

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

• H01M2004/027

  Negative electrodes · CPC title

• H01M4/133 Primary

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

• H01M4/622 Primary

  being polymers · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title