CARBON AND CARBON PRECURSORS IN NANOFIBERS

• US 20150076742A1
• Filed: 08/12/2014
• Published: 03/19/2015
• Est. Priority Date: 03/14/2013
• Status: Abandoned Application

• Current Assignee: Cornell University
• Original Assignee: Cornell University
• Inventors: Joo, Yong Lak, Kim, Kyoung Woo, Kim, Yong Seok
• Application Number:
  US14/457,994
• Publication Number:
  US 20150076742A1
• Time in Patent Office: Days
• US Class Current: 264/433
• CPC Class Codes: D01D 1/02 Preparation of spinning solutions
• CPC Class Codes: D01D 5/0015 characterised by the initial state of the material
• CPC Class Codes: D01D 5/003 the material being a polymer solution or dispersion D01D5/0053 takes precedence
• CPC Class Codes: D01D 5/0069 characterised by the spinning section, e.g. capillary tube, protrusion or pin
• CPC Class Codes: D01F 1/02 Addition of substances to the spinning solution or to the melt addition of substances to viscose D01F2/08
• CPC Class Codes: D01F 9/12 Carbon filaments; Apparatus specially adapted for the manufacture thereof
• CPC Class Codes: D01F 9/20 from polyaddition, polycondensation or polymerisation products D01F9/145, D01F9/16, D01F9/18 take precedence
• CPC Class Codes: D01F 9/328 for manufacturing filaments from polyaddition, polycondensation, or polymerisation products
• CPC Class Codes: D04H 1/728 by electro-spinning electro-spinning methods and apparatus D01D5/0007
• 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 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

Provided herein are nanofibers comprising carbon precursors, nanofibers comprising carbon matrices, and processes for preparing the same. In specific examples, provided herein are high performance lithium ion battery anodic nanofibers comprising non-aggregated silicon domains in a continuous carbon matrix.

Claims

1. A process for preparing a silicon-carbon nanocomposite nanofiber, the process comprising:

a. providing a fluid stock comprising polyvinylalcohol, a plurality of silicon nanoparticles, and a nanostructured carbon;

b. electrospinning the fluid stock, producing a nanofiber comprising the polyvinylalcohol, the silicon nanoparticles, and the nanostructured carbon; and

c. thermally treating the nanofiber producing the silicon-carbon nanocomposite nanofiber.

2. The process of claim 1, wherein the electrospinning is gas-assisted.

3. The process of claim 2, wherein the electrospinning is coaxially gas-assisted.

4. The process of claim 1, wherein the fluid stock is aqueous.

5. The process of claim 3, wherein the fluid stock is aqueous.

6. The process of claim 1, wherein the nanostructured carbon comprises high aspect ratio nanostructured carbon, the aspect ratio thereof being at least 10.

7. The process of claim 1, wherein the nanostructured carbon comprises carbon black, graphene, or carbon nanotubes.

8. The process of claim 1, wherein the nanostructured carbon comprises graphene or carbon nanotubes.

9. The process of claim 6, wherein the nanostructured carbon comprises graphene or carbon nanotubes.

10. The process of claim 1, wherein the plurality of silicon nanoparticles have an average diameter of less than 100 nm.

11. The process of claim 1, wherein the fluid stock comprises the nanostructured carbon and the polyvinyl alcohol in a weight-to-weight ratio of at least 1:

10.

12. The process of claim 1, wherein the fluid stock comprises the nanostructured carbon and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1.

13. The process of claim 3, wherein the fluid stock comprises the nanostructured carbon and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1.

14. The process of claim 9, wherein the fluid stock comprises the nanostructured carbon and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1.

15. The process of claim 1, wherein the fluid stock comprises the silicon nanoparticles and the polyvinyl alcohol in a weight-to-weight ratio of at least 1:

10.

16. The process of claim 1, wherein the fluid stock comprises the silicon nanoparticles and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1.

17. The process of claim 10, wherein the fluid stock comprises the silicon nanoparticles and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1.

18. The process of claim 1, wherein the silicon-carbon nanocomposite nanofiber comprises at least 60 elemental wt. % silicon.

19. The process of claim 1, wherein the silicon-carbon nanocomposite nanofiber comprises at least 75 elemental wt. % silicon.

20. The process of claim 1, wherein the silicon-carbon nanocomposite nanofiber comprises 5 wt. % to 25 wt. % carbon.

21. The process of claim 1, wherein thermally treating comprises heating to a temperature between 400°

C. and 2000°

C.

22. The process of claim 1, wherein the thermal treatment carbonizes the polyvinylalcohol.

23. The process of claim 1, wherein the thermal treatment is performed under inert or reducing conditions.

24. The process of claim 1, further comprising washing the nanofiber prior to thermal treatment.

30. A silicon-carbon nanocomposite nanofiber produced by the process of claim 1.

25. A process for preparing a silicon-carbon nanocomposite nanofiber, the process comprising:

a. providing an aqueous fluid stock comprising polyvinylalcohol, a plurality of silicon nanoparticles having an average diameter of less than 100 nm, and a nanostructured carbon having an aspect ratio of at least 5, the weight-to-weight ratio of silicon nanoparticles to polyvinylalcohol being at least 1;

10, and the weight-to-weight ratio of nanostructured carbon to polyvinylalcohol being at least 1;

10;

b. electrospinning the fluid stock, producing a nanofiber comprising the polyvinylalcohol, the silicon nanoparticles, and the nanostructured carbon, the electrospinning being coaxially gas assisted; and

c. thermally carbonizing the polyvinylalcohol of the nanofiber, thereby producing the silicon-carbon nanocomposite nanofiber.

26. The process of claim 25, wherein the fluid stock comprises the silicon nanoparticles and the polyvinyl alcohol in a weight-to-weight ratio of 1:

4 to 4;

1 and the nanostructured carbon and the polyvinyl alcohol in a weight-to-weight ratio of 1;

4 to 4;

1.

27. The process of claim 25, wherein the nanostructured carbon comprises carbon nanotubes or graphene.

28. The process of claim 25, wherein the silicon-carbon nanocomposite nanofiber comprises at least 60 elemental wt. % silicon and 5 wt. % to 25 wt. % carbon.

29. The process of claim 27, wherein the silicon-carbon nanocomposite nanofiber comprises at least 60 elemental wt. % silicon and 5 wt. % to 25 wt. % carbon.