Silicon-carbon composite, negative electrode comprising same, secondary battery using silicon-carbon composite, and method for preparing silicon-carbon composite

Patent metadata

Field	Value
Publication number	US-10249872-B2
Application number	US-201515311945-A
Country	US
Kind code	B2
Filing date	Jun 10, 2015
Priority date	Jun 13, 2014
Publication date	Apr 2, 2019
Grant date	Apr 2, 2019

Abstract

The present specification relates to a silicon-carbon composite, a negative electrode including the same, a secondary battery using the silicon-carbon composite, and a method for preparing the silicon-carbon composite.

First claim

The invention claimed is:

1. A silicon-carbon composite comprising:
a carbon assembly having a plurality of carbon nanowires or carbon nanotubes assembled, and having mesopores perforated in a length direction between a plurality of the carbon nanowires or the carbon nanotubes; and
a silicon-based material provided in the mesopores of the carbon assembly,
wherein a percentage of the mesopores provided with the silicon-based material is greater than or equal to 20% and less than or equal to 95% based on the total mesopores of the carbon assembly.

2. The silicon-carbon composite of claim 1 , wherein the carbon assembly is obtained by a plurality of the carbon nanowires or the carbon nanotubes being uniformly distributed in a hexagonal form and assembled.

3. The silicon-carbon composite of claim 1 , wherein the silicon-based material includes at least one of a silane-based compound, silicon, and lithiated silicon.

4. The silicon-carbon composite of claim 1 , wherein the silicon-based material is a silicon-based particle.

5. The silicon-carbon composite of claim 4 , wherein a diameter of the silicon-based particle provided in the mesopores of the carbon assembly corresponds to a diameter of the mesopore of the carbon assembly.

6. The silicon-carbon composite of claim 1 , wherein a diameter of the mesopore of the carbon assembly is 100 nm or less.

7. The silicon-carbon composite of claim 1 , wherein the carbon assembly is a carbon assembly particle.

8. The silicon-carbon composite of claim 7 , wherein a diameter of the carbon assembly particle is greater than or equal to 0.1 μm and less than or equal to 10 μm.

9. The silicon-carbon composite of claim 1 , wherein a mass ratio of the carbon assembly and the silicon-based material is from 1:1 to 1:5.

10. A negative electrode comprising the silicon-carbon composite of claim 1 .

11. A secondary battery comprising:
a positive electrode;
a negative electrode including the silicon-carbon composite of claim 1 ; and
a separator provided between the positive electrode and the negative electrode.

12. A battery module including the secondary battery of claim 11 as a unit battery.

13. A method for preparing the silicon-carbon composite of claim 1 comprising:
penetrating a silicon-based compound into mesopores of a carbon assembly having the mesopores perforated in a length direction between a plurality of carbon nanowires or carbon nanotubes by assembling a plurality of the carbon nanowires or the carbon nanotubes.

14. The method for preparing a silicon-carbon composite of claim 13 , wherein the silicon-based compound penetrating into the mesopores of the carbon assembly includes at least one of a silane-based compound, silicon, and lithiated silicon.

15. The method for preparing a silicon-carbon composite of claim 13 , wherein the step of penetrating the silicon-based compound into mesopores of the carbon assembly is penetrating a silane-based compound into the mesopores of the carbon assembly.

16. The method for preparing a silicon-carbon composite of claim 15 , wherein the silane-based compound is silane or halogenated silane.

17. The method for preparing a silicon-carbon composite of claim 13 , further comprising:
heat treating the carbon assembly into which the silicon-based compound penetrates.

18. The method for preparing a silicon-carbon composite of claim 17 , further comprising:
reacting the silicon-based compound penetrating into the heat treated carbon assembly with lithium metal or iodized lithium.

19. The method for preparing a silicon-carbon composite of claim 13 , wherein the step of penetrating the silicon-based compound into mesopores of the carbon assembly is penetrating a silane-based compound into the mesopores of the carbon assembly, and further comprising:
heat treating the carbon assembly into which the silane-based compound penetrates; and
reacting the carbon assembly with lithium metal or iodized lithium after the heat treatment.

Assignees

• Lg Chemical Ltd

Inventors

• Jang Minchul
• Kim Jeong Kyu
• Kim Yoo Seok
• Kim Suhwan
• Yoo Jinhyoung
• Sung Da Young

Classifications

• H01M4/62

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

• H01M4/587

  for inserting or intercalating light metals · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• C01B32/168

  After-treatment · CPC title