Energy storage devices including silicon and graphite

• US 9,431,181 B2
• Filed: 04/25/2014
• Issued: 08/30/2016
• Est. Priority Date: 02/25/2009
• Status: Active Grant

• Current Assignee: CF Traverse LLC (SoftBank Group Corp.)
• Original Assignee: Catalyst Power Technologies
• Inventors: Rojeski, Ronald A
• Primary Examiner(s): GATEWOOD, DANIEL S
• Application Number:
  US14/262,528
• Publication Number:
  US 20140234713A1
• Time in Patent Office: 858 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: H01G 11/30 characterised by their material
• CPC Class Codes: H01G 11/32 Carbon-based
• CPC Class Codes: H01G 11/36 Nanostructures, e.g. nanofibres, nanotubes or fullerenes
• CPC Class Codes: H01G 11/46 Metal oxides
• CPC Class Codes: H01G 11/50 specially adapted for lithium-ion capacitors, e.g. for lithium-doping or for intercalation
• 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 4/131 Electrodes based on mixed oxides or hydroxides, or on mixtures of oxides or hydroxides, e.g. LiCoOx
• CPC Class Codes: H01M 4/133 Electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/366 as layered products
• CPC Class Codes: H01M 4/70 characterised by shape or form
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/13 Energy storage using capacitors
• CPC Class Codes: Y10S 977/734 Fullerenes, i.e. graphene-based structures, such as nanohorns, nanococoons, nanoscrolls or fullerene-like structures, e.g. WS2 or MoS2 chalcogenide nanotubes, planar C3N4, etc.

Abstract

A novel hybrid lithium-ion anode material based on coaxially coated Si shells on vertically aligned carbon nanofiber (CNF) arrays. The unique cup-stacking graphitic microstructure makes the bare vertically aligned CNF array an effective Li⁺ intercalation medium. Highly reversible Li⁺ intercalation and extraction were observed at high power rates. More importantly, the highly conductive and mechanically stable CNF core optionally supports a coaxially coated amorphous Si shell which has much higher theoretical specific capacity by forming fully lithiated alloy. Addition of surface effect dominant sites in close proximity to the intercalation medium results in a hybrid device that includes advantages of both batteries and capacitors.

Claims

1. An energy storage system comprising:

a first electrode disposed in a first region of electrolyte and including a substrate,

an ion absorbing material attached to the substrate the ion adsorbing material including silicon and a over-layer including graphite, wherein the over-layer including graphite covers at least part of silicon, and

support filaments in contact with the ion absorbing material, the ion absorbing material covering less than 25% of each of the support filaments;

a separator configured to separate the first region and a second region of electrolyte; and

a second electrode disposed in the second region of electrolyte, the first and second electrodes and separator configured to operate as an energy storage device.

2. The system of claim 1, wherein the ion adsorbing material further includes at least one of nickel, cobalt, chromium, titanium, aluminum, copper, silver, gold, tungsten, molybdenum and iron.

3. The system of claim 1, wherein the graphite includes graphene.

4. The system of claim 1, wherein the ion adsorbing material includes silicon particles.

26. The system of claim 1, wherein support filaments include a metal.

28. The system of claim 1, wherein the ion adsorbing material includes a 3d metal oxide.

5. An energy storage system comprising:

a first electrode disposed in a first region of electrolyte and including

a substrate,

an ion absorbing material attached to the substrate, the ion adsorbing material including silicon and a layer including graphene, and

support filaments configured to provide a path for electrons between the substrate and the ion absorbing material, wherein the ion adsorbing material is attached to the substrate by a mesh of the support filaments;

a separator configured to separate the first region and a second region of electrolyte; and

a second electrode disposed in the second region of electrolyte, the first and second electrodes and separator configured to operate as an energy storage device.

6. The system of claim 5, wherein the ion absorbing material further includes silicon oxide.

7. The system of claim 5, wherein the ion adsorbing material includes silicon particles.

8. The system of claim 5, wherein the ion adsorbing material includes nanoparticles of metal oxide.

9. The system of claim 5, wherein the ion adsorbing material includes a metal.

10. The system of claim 5, wherein the ion adsorbing material includes a 3d metal oxide.

11. The system of claim 5, wherein the ion adsorbing material includes silicon encapsulated by carbon.

12. The system of claim 11, wherein the carbon includes a diamond like coating.

13. The system of claim 5, wherein the ion adsorbing material is passivated by a coating including carbon.

14. The system of claim 5, wherein the first electrode further includes titanium disposed in proximity to the ion absorbing material.

23. The system of claim 5, wherein the ion adsorbing material further includes at least one of nickel, cobalt, chromium, titanium, aluminum, copper, silver, gold, tungsten, molybdenum and iron.

30. The energy storage system of claim 5, wherein the support filaments include carbon nanofibers or metal nanowires.

32. The system of claim 5, wherein the ion absorbing material covers less than 25% of each of the support filaments.

33. The system of claim 7, wherein the silicon particles are between 0.1 and 0.6 μ

m in diameter.

34. The system of claim 7, wherein the silicon particles are between 0.1 and 1.0 μ

m in diameter.

36. The system of claim 5, wherein a binder is configured to hold the ion absorbing material and the support filaments proximate to the substrate.

15. An energy storage system comprising:

a first electrode disposed in a first region of electrolyte and including

support filaments,

a substrate,

an ion absorbing material attached to the substrate and the support filaments, the ion adsorbing material including silicon and graphite, and

an over-layer covering at least part of the ion absorbing material;

a separator configured to separate the first region and a second region of electrolyte; and

a second electrode disposed in the second region of electrolyte, the first and second electrodes and separator configured to operate as an energy storage device.

16. The energy storage system of claim 15, wherein the support filaments include carbon nanofibers.

17. The energy storage system of claim 15, wherein the support filaments include metal wires.

18. The energy storage system of claim 15, wherein the support filaments are vertically aligned.

19. The energy storage system of claim 15, wherein the support filaments are attached to the substrate by a binder configured to hold support filaments in proximity to the substrate.

20. The energy storage system of claim 15, wherein the support filaments are attached to the substrate at one end of each of the support filaments.

21. The system of claim 15, wherein the ion adsorbing material includes nanoparticles.

22. The system of claim 15, wherein the ion absorbing material covers less than 25% of each of the support filaments.

24. The system of claim 15, wherein the ion adsorbing material further includes at least one of nickel, cobalt, chromium, titanium, aluminum, copper, silver, gold, tungsten, molybdenum and iron.

25. The system of claim 15, wherein the ion adsorbing material includes silicon coated by carbon.

27. The system of claim 15, wherein the ion adsorbing material includes a metal.

29. The system of claim 15, wherein the ion adsorbing material includes a 3d metal oxide.

31. The energy storage system of claim 15, wherein the ion adsorbing material is passivated by a coating including carbon.

35. The system of claim 19, wherein the binder includes graphene.

37. The system of claim 15, wherein the ion absorbing material includes silicon particles and the graphite is disposed in a layer on the silicon.

38. The system of claim 15, wherein the ion absorbing material includes silicon particles and the graphite at least partially encapsulates the silicon.

39. The energy storage system of claim 15, wherein the support filaments include carbon nanotubes.

40. The energy storage system of claim 15, wherein the support filaments are disposed in a mesh.

41. The energy storage system of claim 15, wherein the support filaments include carbon nano fibers.