Lithium-doped silicon-based oxide negative electrode active material, method of preparing the same, and negative electrode and secondary battery including the same

Patent metadata

Field	Value
Publication number	US-11958750-B2
Application number	US-202117325294-A
Country	US
Kind code	B2
Filing date	May 20, 2021
Priority date	May 21, 2020
Publication date	Apr 16, 2024
Grant date	Apr 16, 2024

Abstract

Provided are a negative electrode active material which includes negative electrode active material particles which includes a silicon oxide (SiOx, 0<x≤2); and at least one lithium silicate selected from Li2SiO3, Li2Si2O5, and Li4SiO4 in at least a part of the silicon oxide. The negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm−1 and less than 500 cm−1. Also provided are a method of preparing the same, and a negative electrode and a lithium secondary battery including the negative electrode active material.

First claim

What is claimed is:

1. A negative electrode active material comprising:
negative electrode active material particles including a silicon oxide (SiO x , 0<x≤2) and at least one lithium silicate selected from Li 2 SiO 3 , Li 2 Si 2 O 5 , and Li 4 SiO 4 in at least a part of the silicon oxide,
wherein the negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm −1 and less than 500 cm −1 , and
wherein the negative electrode active material particles have a peak area ratio DIE according to an X-ray diffraction analysis method of less than 5.54 (D is an area of a Li 2 Si 2 O 5 peak positioned at 24.9±0.3″, and E is an area of a Li 2 SiO 3 peak positioned at 26.9±0.3″ in X-ray diffraction analysis).

2. The negative electrode active material of claim 1 , wherein the negative electrode active material particles have a maximum peak position by a Raman spectrum of 480 cm −1 or less.

3. The negative electrode active material of claim 1 , wherein the negative electrode active material particles have a peak intensity ratio Ia/Ib by the Raman spectrum of 1.20 or less, wherein Ia is a peak intensity of 515±15 cm −1 and Ib is a peak intensity of 470±30 cm−1 in the Raman spectrum.

4. The negative electrode active material of claim 3 , wherein the peak intensity ratio Ia/Ib by the Raman spectrum is 0.4 or less.

5. The negative electrode active material of claim 1 , wherein the negative electrode active material particles include 10 wt % or more and less than 100 wt % of the lithium silicate with respect to a total weight.

6. The negative electrode active material of claim 1 , wherein the negative electrode active material particles have a peak area ratio C/D according to the X-ray diffraction analysis method of less than 45.99, wherein C is an area of a Si peak positioned at 28.4±0.3°, and D is an area of a Li 2 Si 2 O 5 peak positioned at 24.9±0.3° in the X-ray diffraction analysis.

7. The negative electrode active material of claim 1 , wherein the negative electrode active material particles have a peak area ratio C/E according to the X-ray diffraction analysis method of less than 8.75, wherein C is an area of a Si peak positioned at 28.4±0.3°, and E is an area of a Li 2 SiO 3 peak positioned at 26.9±0.3° in the X-ray diffraction analysis.

8. The negative electrode active material of claim 7 , wherein the peak area ratio C/E according to the X-ray diffraction analysis method is less than 1.1.

9. The negative electrode active material of claim 1 , wherein the negative electrode active material particles include substantially no Li 4 SiO 4 .

10. The negative electrode active material of claim 1 , wherein the negative electrode active material includes 50 wt % or more of the negative electrode active material particles with respect to the total weight.

11. A method of preparing the negative electrode active material of claim 1 , the method comprising:
preparing silicon compound particles; and
mixing silicon compound particles and a Li precursor and performing heat treatment to prepare negative electrode active material particles including a silicon oxide (SiO x , 0<x≤2) and at least one lithium silicate selected from Li 2 SiO 3 , Li 2 Si 2 O 5 , and Li 4 SiO 4 in at least a part of the silicon oxide,
wherein the negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm −1 and less than 500 cm −1 .

12. A negative electrode comprising: a negative electrode active material layer including: the negative electrode active material of claim 1 and a water-based binder.

13. A lithium secondary battery comprising: the negative electrode of claim 12 ; a positive electrode; a separator positioned between the negative electrode and the positive electrode; and an electrolyte.

14. A negative electrode active material comprising:
negative electrode active material particles including a silicon oxide (SiO x , 0<x≤2) and at least one lithium silicate selected from Li 2 SiO 3 , Li 2 Si 2 O 5 , and Li 4 SiO 4 in at least a part of the silicon oxide,
wherein the negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm −1 and less than 500 cm −1 , and
wherein the negative electrode active material particles have a peak area ratio C/D according to the X-ray diffraction analysis method of less than 45.99 (C is an area of a Si peak positioned at 28.4±0.3°, and D is an area of a Li 2 Si 2 O 5 peak positioned at 24.9±0.3° in the X-ray diffraction analysis).

15. A negative electrode active material comprising:
negative electrode active material particles including a silicon oxide (SiO x , 0<x≤2) and at least one lithium silicate selected from Li 2 SiO 3 , Li 2 Si 2 O 5 , and Li 4 SiO 4 in at least a part of the silicon oxide,
wherein the negative electrode active material particles have a maximum peak position by a Raman spectrum of more than 460 cm −1 and less than 500 cm −1 , and
wherein the negative electrode active material particles have a peak area ratio C/E according to the X-ray diffraction analysis method of less than 8.75 (C is an area of a Si peak positioned at 28.4±0.3°, and E is an area of a Li 2 SiO 3 peak positioned at 26.9±0.3° in the X-ray diffraction analysis).

Assignees

• Sk On Co Ltd

Inventors

• Park Eunjun
• Kim Joon-Sup
• Park Gwi Ok
• Yoon Jeongbae
• Lee Suk Chin
• Kim Hansu
• Youn Donghan
• Chung Dong Jae

Classifications

• H01M4/62

  Selection of inactive substances as ingredients for active masses, e.g. binders, fillers · CPC title

• H01M4/483 Primary

  for non-aqueous cells (H01M4/485 takes precedence) · CPC title

• C01B33/24 Primary

  Alkaline-earth metal silicates · CPC title

• H01M10/0525

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

• C01P2002/74

  by peak-intensities or a ratio thereof only · CPC title