Nano-featured porous silicon materials

• US 10,763,501 B2
• Filed: 08/12/2016
• Issued: 09/01/2020
• Est. Priority Date: 08/14/2015
• Status: Active Grant

• Current Assignee: Group14 Technologies Inc.
• Original Assignee: Group14 Technologies Inc.
• Inventors: Feaver, Aaron M., Thompkins, Leah A., Geramita, Katharine, Kron, Benjamin E., Sakshaug, Avery J., Fredrick, Sarah, Costantino, Henry R., Goodwin, Chad, Timmons, Christopher, Afkhami, Farshid, Strong, Adam
• Primary Examiner(s): Ahmed, Shamim
• Application Number:
  US15/752,566
• Publication Number:
  US 20180331356A1
• Time in Patent Office: 1,481 Days
• Field of Search: None
• CPC Class Codes: C01B 33/021 Preparation chemical coating from the vapour phase C23C16/00
• CPC Class Codes: C01P 2002/72 by d-values or two theta-values, e.g. as X-ray diagram
• CPC Class Codes: C01P 2002/85 by XPS, EDX or EDAX data
• CPC Class Codes: C01P 2004/03 obtained by SEM
• CPC Class Codes: C01P 2006/10 Solid density
• CPC Class Codes: C01P 2006/11 Powder tap density
• CPC Class Codes: C01P 2006/12 Surface area
• CPC Class Codes: C01P 2006/14 Pore volume
• CPC Class Codes: C01P 2006/16 Pore diameter
• CPC Class Codes: C01P 2006/17 Pore diameter distribution
• CPC Class Codes: C01P 2006/21 Attrition-index or crushing strength of granulates
• CPC Class Codes: C01P 2006/40 Electric properties
• CPC Class Codes: C01P 2006/80 Compositional purity
• CPC Class Codes: C23F 1/00 Etching metallic material by chemical means manufacture of printing surfaces B41C; manufacture of printed circuits H05K
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 2004/021 Physical characteristics, e.g. porosity, surface area
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H01M 8/1037 : having silicon, e.g. sulfonated crosslinked polydimethylsiloxanes
• CPC Class Codes: Y02E 60/10 : Energy storage using batteries
• CPC Class Codes: Y02E 60/50 : Fuel cells

Abstract

Porous silicon and methods for preparation and use of the same are disclosed. The porous silicon materials have utility either alone or in combination with other materials, for example, combined with carbon particles for energy storage applications.

Claims

1. A method for producing nano-featured porous silicon particles comprising:

a) heating particles of a silicon metal alloy at a temperature between 350 and 850°

C. in the presence of nitrogen;

b) holding a mixture of an etching gas comprising chlorine, hydrochloric acid, fluorine, or combinations thereof, and the particles of the silicon metal alloy at a temperature between 350 and 850°

C., to allow for creation of a metal chloride, metal fluoride, or combinations thereof; and

c) cooling the mixture, and removing the metal chloride, metal fluoride, or combinations thereof, to yield the nano-featured porous silicon particles.

2. The method of claim 1, wherein the silicon metal alloy comprises Al—

Si.

3. The method of claim 1, wherein the mixture is held at a temperature between 450 and 550°

.

4. The method of claim 1, wherein the etching gas comprises chlorine.

5. The method of claim 1, wherein the etching gas comprises hydrochloric acid.

6. The method of claim 1, wherein the etching gas comprises fluorine.

7. The method of claim 1, wherein the heating and holding is performed in a kiln or fluidized bed reactor.

8. The method of claim 7, wherein the kiln is a roller hearth kiln, rotary kiln, or elevator kiln.

9. The method of claim 1, wherein the nano-featured porous silicon particles comprise a skeletal density less than 2.2 g/cm³, as measured by helium pcynometry.

10. The method of claim 1, wherein the nano-featured porous silicon particles comprise a friability greater than 10%.

11. The method of claim 1, wherein the nano-featured porous silicon particles comprise a characteristic thickness of nano features of less than 300 nm.

12. The method of claim 1, wherein the nano-featured porous silicon particles comprise a characteristic distance between silicon nano features of less than 300 nm.

13. The method of claim 1, wherein the nano-featured porous silicon particles comprise a specific surface area between 30 and 230 m²/g and a pore volume between 0.1 and 0.5 cm³/g.

14. The method of claim 1, wherein the nano-featured porous silicon particles comprise less than 40% micropores, between 30 and 40% mesopores, and between 20 and 30% macropores.

15. The method of claim 1, wherein the nano-featured porous silicon particles comprise less than 20% micropores, between 30 and 60% mesopores, and between 20 and 50% macropores.

16. The method of claim 1, wherein the nano-featured porous silicon particles comprise less than 10% micropores, between 40 and 70% mesopores, and between 20 and 50% macropores.

17. The method of claim 1, wherein the nano-featured porous silicon particles comprise less than 5% micropores, between 40 and 50% mesopores, and between 40 and 50% macropores.

18. The method of claim 1, wherein the nano-featured porous silicon particles comprise less than 2% micropores, between 40 and 50% mesopores, and between 50 and 60% macropores.

19. The method of claim 1, wherein the nano-featured porous silicon particles exhibit a capacity of at least 1600 mAh/g and an average Coulombic efficiency of at least 0.98 when tested in a lithium ion half-cell cycled between 0.8 V and 0.005 V, where the counter electrode is lithium metal, the electrolyte comprises 1M LiPF₆ in a solvent comprised of 2:

1 iethylene carbonate;

diethyl carbonate (EC;

DEC) and 10% (w/w) fluoroethylenecarbonate (FEC) and employing a polypropylene separator.

20. The method of claim 1, wherein the nano-featured porous silicon particles exhibit a capacity of at least 2300 mAh/g and an average Coulombic efficiency of at least 0.97.

21. The method of claim 1, wherein the nano-featured porous silicon particles comprise an oxygen content from 1 to 20% by weight, and an aluminum content from 1 to 30% by weight.

22. The method of claim 1, wherein the nano-featured porous silicon particles comprise a Dv50 less than 1000 nm.

23. The method of claim 1, wherein the nano-featured porous silicon particles comprise a surface area of 30 to 120 m²/g, a pore volume of 0.08 to 0.3 cm³/g, wherein the pore volume comprises 5 to 40% micropores, 35-70% mesopores, and 30-60% macropores.

24. The method of claim 1, wherein the nano-featured porous silicon particles comprise a surface area of 30 to 120 m²/g, and a pore volume of 0.09 to 0.18 cm³/g, wherein the pore volume is comprised of 5 to 15% micropores, 45-55% mesopores, and 30-45% macropores.