Highly efficient manufacturing of silicon-carbon composites materials comprising ultra low Z

Patent metadata

Field	Value
Publication number	US-11611070-B2
Application number	US-202217715840-A
Country	US
Kind code	B2
Filing date	Apr 7, 2022
Priority date	Aug 18, 2020
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

Silicon-carbon composite materials and related processes are disclosed that overcome the challenges for providing amorphous nano-sized silicon entrained within porous carbon. Compared to other, inferior materials and processes described in the prior art, the materials and processes disclosed herein find superior utility in various applications, including energy storage devices such as lithium ion batteries.

First claim

The invention claimed is:

1. A process for preparing silicon-carbon composite particles comprising:
a. providing a carbon scaffold comprising a pore volume, wherein the pore volume comprises greater than 70% microporosity;
b. heating the porous carbon scaffold to a temperature from 300° C. to 500° C.;
c. contacting the carbon scaffold with a silane feedstock gas corresponding to a Y CVI less than 0.5 wherein Y CVI =(mol of silane feedstock gas per hour)/(mol of carbon scaffold); and
d. wherein X Si of the process is greater than 50%, wherein X Si =100×(mol of silicon in the silicon-carbon composite)/(mol silane feedstock gas), wherein the mol silicon in the silicon-carbon composite is determined from the silicon content in the silicon-carbon composite by thermogravimetric analysis.

2. The process for preparing silicon-carbon composite particles of claim 1 , wherein the pore volume comprises greater than 90% microporosity.

3. The process for preparing silicon-carbon composite particles of claim 1 , wherein the silicon-carbon composite particles comprise a surface area less than 10 m 2 /g.

4. The process for preparing silicon-carbon composite particles of claim 1 , wherein the silicon-carbon composite particles comprise a Dv50 ranging from 5 nm to 20 microns.

5. The process for preparing silicon-carbon composite particles of claim 1 , wherein the feedstock gas comprises silane and an inert gas selected from nitrogen, hydrogen, argon, and helium, and combinations thereof.

6. The process for preparing silicon-carbon composite particles of claim 1 , wherein the concentration of silane as the mass fraction of the total feedstock gas composition is 1.25% to 100%.

7. The process for preparing silicon-carbon composite particles of claim 1 , wherein the process is a batch process.

8. The process for preparing silicon-carbon composite particles of claim 1 , wherein the process is a continuous process.

9. The process for preparing silicon-carbon composite particles of claim 1 , wherein the process is conducted in a fluidized bed reactor.

10. The process for preparing silicon-carbon composite particles of claim 1 , wherein the porous carbon scaffold comprises a span (Dv50)/(Dv90-Dv10) from 100 to less than 1.

11. The process for preparing silicon-carbon composite particles of claim 1 , wherein the silane gas comprises a recycle stream.

12. The process for preparing silicon-carbon composite particles of claim 11 , wherein the recycle stream comprises a purge stream.

13. The process for preparing silicon-carbon composite particles of claim 1 , wherein the flow rate of the silane feedstock gas is varied and Y CVI is less than 0.5 wherein Y CVI =(overall mol of silane feedstock gas per hour)/(mol of carbon scaffold).

14. A process for preparing silicon-carbon composite particles comprising:
a. providing a carbon scaffold comprising a pore volume, wherein the pore volume comprises greater than 70% microporosity;
b. heating the porous carbon scaffold to a temperature from 350° C. to 550° C.;
c. contacting the carbon scaffold with a silane feedstock gas corresponding to a Y CVI less than 0.5 wherein Y CVI =(mole of silane feedstock gas per hour)/(mol of carbon scaffold);
d. wherein X Si of the process is greater than 60%, wherein X Si =100×(mol of silicon in the silicon-carbon composite)/(mol silane feedstock gas), wherein the mol silicon in the silicon-carbon composite is determined from the silicon content in the silicon-carbon composite by thermogravimetric analysis; and
e. wherein the silane gas comprises a recycle stream.

15. The process for preparing silicon-carbon composite particles of claim 14 , wherein the pore volume comprises greater than 90% microporosity.

16. The process for preparing silicon-carbon composite particles of claim 14 , wherein the silicon-carbon composite particles comprise a surface area less than 10 m 2 /g.

17. The process for preparing silicon-carbon composite particles of claim 14 , wherein the silicon-carbon composite particles comprise a Dv50 ranging from 5 nm to 20 microns.

18. The process for preparing silicon-carbon composite particles of claim 14 , wherein the feedstock gas comprises silane and an inert gas selected from nitrogen, hydrogen, argon, and helium, and combinations thereof.

19. The process for preparing silicon-carbon composite particles of claim 14 , wherein the concentration of silane as a mass fraction of the total feedstock gas composition is 1.25% to 100%.

20. The process for preparing silicon-carbon composite particles of claim 14 , wherein the process is performed in a fluidized bed reactor.

21. The process for preparing silicon-carbon composite particles of claim 14 , wherein the porous carbon scaffold comprises a span (Dv50)/(Dv90-Dv10) from 100 to less than 1.

22. The process for preparing silicon-carbon composite particles of claim 14 , wherein the recycle stream comprises a purge stream.

23. The process for preparing silicon-carbon composite particles of claim 14 , wherein the flow rate of the silane feedstock gas is varied and Y CVI is less than 0.5 wherein Y CVI =(overall mol of silane feedstock gas per hour)/(mol of carbon scaffold).

24. A process for preparing silicon-carbon composite particles comprising:
a. providing a carbon scaffold comprising a pore volume, wherein the pore volume comprises greater than 70% microporosity;
b. heating the porous carbon scaffold to a temperature from 350° C. to 550° C.;
c. contacting the carbon scaffold with a silane feedstock gas corresponding to a Y CVI less than 0.3 wherein Y CVI =(mole of silane feedstock gas per hour)/(mol of carbon scaffold);
d. wherein X Si of the process is greater than 70%, wherein X Si =100×(mol of silicon in the silicon-carbon composite)/(mol silane feedstock gas), wherein the mol silicon in the silicon-carbon composite is determined from the silicon content in the silicon-carbon composite by thermogravimetric analysis; and
e. wherein the silane gas comprises a recycle stream.

25. The process for preparing silicon-carbon composite particles of claim 24 , wherein the pore volume comprises greater than 90% microporosity.

26. The process for preparing silicon-carbon composite particles of claim 24 , wherein the silicon-carbon composite particles comprise a surface area less than 10 m 2 /g.

27. The process for preparing silicon-carbon composite particles of claim 24 , wherein the silicon-carbon composite particles comprise a Dv50 ranging from 5 nm to 20 microns.

28. The process for preparing silicon-carbon composite particles of claim 24 , wherein the feedstock gas comprises silane and an inert gas selected from nitrogen, hydrogen, argon, and helium, and combinations thereof.

29. The process for preparing silicon-carbon composite particles of claim 24 , wherein the concentration of silane as a mass fraction of the total feedstock gas composition is 1.25% to 100%.

30. The process for preparing silicon-carbon composite particles of claim 24 , wherein the process is performed in a fluidized bed reactor.

31. The process for preparing silicon-carbon composite particles of claim 24 , wherein the porous carbon scaffold comprises a span (Dv50)/(Dv90-Dv10) from 100 to less than 1.

32. The process for preparing silicon-carbon composite particles of claim 24 , wherein

Assignees

• Group14 Technologies Inc

Inventors

• Costantino Henry R
• Dhanabalan Abirami
• Sakshaug Avery J
• Timmons Christopher
• Patel Rajankumar

Classifications

• H01M4/386

  Silicon or alloys based on silicon · CPC title

• H01M10/052

  Li-accumulators · CPC title

• C01B33/00

  Silicon; Compounds thereof ({C01B6/00,} C01B21/00, C01B23/00 take precedence; persilicates C01B15/14; carbides C01B32/956) · CPC title

• C04B38/0032

  one of the precursor materials being a monolithic element having approximately the same dimensions as the final article, e.g. a paper sheet which after carbonisation will react with silicon to form a porous silicon carbide porous body · CPC title

• H01M4/587

  for inserting or intercalating light metals · CPC title