Anode active material for lithium secondary battery, method of forming the same and lithium secondary battery including the same

Patent metadata

Field	Value
Publication number	US-11688854-B2
Application number	US-202217692881-A
Country	US
Kind code	B2
Filing date	Mar 11, 2022
Priority date	Mar 11, 2021
Publication date	Jun 27, 2023
Grant date	Jun 27, 2023

Abstract

An anode active material for a lithium secondary battery and a lithium secondary battery are provided. The anode active material includes a carbon-based particle including pores formed in at least one of an inside of the particle and a surface of the particle and having a pore size of the carbon-based particle is 20 nm or less, and silicon formed at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle. A peak intensity ratio in a Raman spectrum of silicon defined as I(515)/I(480) is 1.2 or less. Difference between volume expansion ratios of carbon and silicon can be reduced to improve life-span property of the secondary battery.

First claim

What is claimed is:

1. An anode active material for a lithium secondary battery, comprising:
a carbon-based particle comprising pores formed in at least one of an inside of the particle and a surface of the particle, wherein a pore size of the carbon-based particle is 20 nm or less;
a silicon-based compound comprising silicon formed at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle, wherein the silicon-based compound further comprises at least one of silicon oxide (SiOx, 0<x<2) and silicon carbide (SiC),
wherein a peak intensity ratio in a Raman spectrum of silicon defined by Equation 2 is 1.2 or less:
Peak intensity ratio of Raman spectrum= I (515)/ I (480)  [Equation 2]

wherein, in Equation 2, I(515) is a peak intensity of silicon in a region having a wavenumber of 515 cm −1 in the Raman spectrum, and I(480) is a peak intensity of silicon in a region having a wavenumber of 480 cm −1 in the Raman spectrum.

2. The anode active material for a lithium secondary battery of claim 1 , wherein the peak intensity ratio in the Raman spectrum of silicon is 1.0 or less.

3. The anode active material for a lithium secondary battery of claim 1 , wherein silicon has an amorphous structure.

4. The anode active material for a lithium secondary battery of claim 1 , wherein the pore size of the carbon-based particle is less than 10 nm.

5. The anode active material for a lithium secondary battery of claim 1 , wherein the carbon-based particle has an amorphous structure.

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

7. A method of forming an anode active material for a lithium secondary battery, comprising:
preparing a carbon-based particle including pores that have a pore size of 20 nm or less;
injecting a silicon-based compound gas to the carbon-based particle; and
firing the carbon-based particle together with the silicon-based compound gas to deposit a silicon-based compound, the silicon-based compound including silicon and at least one of silicon oxide (SiOx, 0<x<2) and silicon carbide (SiC) at an inside of the pores of the carbon-based particle or on the surface of the carbon-based particle,
wherein a peak intensity ratio in a Raman spectrum of silicon defined by Equation 2 is 1.2 or less:
Peak intensity ratio of Raman spectrum= I (515)/ I (480)  [Equation 2]

wherein, in Equation 2, I(515) is a peak intensity of silicon in a region having a wavenumber of 515 cm −1 in the Raman spectrum, and I(480) is a peak intensity of silicon in a region having a wavenumber of 480 cm −1 in the Raman spectrum.

8. The method of claim 7 , wherein the firing is performed at a temperature less than 600° C.

Assignees

• Sk On Co Ltd

Inventors

• Park Gwi Ok
• Yoo Seok Keun
• Chung Ju Ho

Classifications

• H01M4/587 Primary

  for inserting or intercalating light metals · CPC title

• H01M10/0525

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title

• H01M2004/021

  Physical characteristics, e.g. porosity, surface area · CPC title

• H01M2004/027

  Negative electrodes · CPC title