METHOD OF FABRICATING FIBRES COMPOSED OF SILICON OR A SILICON-BASED MATERIAL AND THEIR USE IN LITHIUM RECHARGEABLE BATTERIES

• US 20100151324A1
• Filed: 01/23/2007
• Published: 06/17/2010
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Liu, Feng-Ming, Green, Mino
• Granted Patent: US 8,101,298 B2
• Time in Patent Office: Days
• US Class Current: 429/220
• CPC Class Codes: C30B 29/06 Silicon
• CPC Class Codes: C30B 29/60 characterised by shape
• CPC Class Codes: C30B 33/08 Etching
• 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 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/0402 Methods of deposition of the material
• 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 4/1393 of electrodes based on carbonaceous material, e.g. graphite-intercalation compounds or CFx
• CPC Class Codes: H01M 4/1395 of electrodes based on metals, Si or alloys
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/5825 Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 29/49115 including coating or impregnating

Abstract

A method of fabricating fibres of silicon or silicon-based material comprises the steps of etching pillars on a substrate and detaching them. A battery anode can then be created by using the fibres as the active material in a composite anode electrode.

Claims

1. A method of fabricating fibres of silicon or a silicon-based material comprising the steps of etching a silicon substrate or a silicon-based substrate to make pillars and detaching the pillars from the substrate.

2. A method as claimed in claim 1 in which the fibres have transverse dimensions in the range 0.08 to 0.5 microns, preferably 0.2 microns and a length in the range 20 to 300 microns preferably 100 microns.

3. A method as claimed in claim 1 in which the fibres have an aspect ratio of about 100:

1.

4. A method as claimed in claim 1 in which the fibres have a substantially circular cross-section.

5. A method as claimed in claim 1 in which the fibres have a substantially non-circular cross-section.

6. A method as claimed in claim 1 in which the pillars are created by reactive ion etching.

7. A method as claimed in claim 1 in which the pillars are created by chemical reaction etching.

8. A method as claimed in claim 7 in which the pillars are created by galvanic exchange etching.

9. A method as claimed in claim 1 in which the pillars are detached by one or more of scraping, agitating or chemical etching.

10. A method as claimed in claim 1 in which the silicon or silicon-based material comprises one of undoped silicon, doped silicon or a silicon germanium mixture.

11. (canceled)

12. A method of creating a cell electrode comprising depositing a slurry containing silicon-based fibres to form a layer of silicon-based fibres.

13. A method as claimed in claim 12 in which the fibres are single crystal fibres.

14. A method as claimed in claim 12 in which the fibres are deposited in a felt.

15. A method as claimed in claim 12 in which the fibres are deposited in a composite.

16. A method as claimed in claim 12 including depositing the fibres on a current collector.

17. A method as claimed in claim 12 in which the fibres are fabricated of silicon or a silicon based material by a method comprising the steps of etching a silicon substrate or a silicon-based substrate to make pillars and detaching the pillars from the substrate.

18. A method as claimed in claim 12 in which the electrode is an anode.

19. A method as claimed in claim 12 in which the felt has a percentage pore volume of about 10-30 percent.

20. A method of fabricating a lithium rechargeable cell comprising the steps of creating an anode as claimed in claim 12 and adding a cathode and an electrolyte.

21. A method as claimed in claim 20 further comprising adding a separator between cathode and the anode.

22-35. -35. (canceled)