Method of fabricating fibres composed of silicon or a silicon-based material and their use in lithium rechargeable batteries

• US 8,597,831 B2
• Filed: 11/01/2011
• Issued: 12/03/2013
• Est. Priority Date: 01/23/2006
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Green, Mino, Liu, Feng-Ming
• Primary Examiner(s): Ruddock, Ula C
• Assistant Examiner(s): GATEWOOD, DANIEL S
• Application Number:
  US13/286,740
• Publication Number:
  US 20120100427A1
• Time in Patent Office: 763 Days
• Field of Search: None
• US Class Current: 429/218.1
• 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

An electrically interconnected mass includes elongated structures. The elongated structures are electrochemically active and at least some of the elongated structures cross over each other to provide intersections and a porous structure. The elongated structures include doped silicon.

Claims

1. An electrode for an electrochemical cell, the electrode comprising an electrically interconnected mass comprising:

elongated structures, wherein the elongated structures are capable of being reversibly charged and discharged and at least some of the elongated structures cross over each other to provide intersections and a porous structure, and wherein the elongated structures comprise silicon;

at least one of a binder and an electronic additive;

wherein the elongated structures and the at least one of the binder and the electronic additive cooperate to define a porous composite electrode layer.

2. An electrode as claimed in claim 1 wherein the elongated structures have a resistivity of 100 to 0.001 Ohm cm.

3. An electrode as claimed in claim 1 wherein at least some of the elongated structures are arranged in a random or disordered manner.

4. An electrode as claimed in claim 1 wherein the structures comprise doped silicon.

5. An electrode as claimed in claim 1 wherein the composite layer has a percentage pore volume of about 10-30 percent.

6. An electrode as claimed in claim 1 wherein the elongated structures have a transverse dimension in the range 0.08 to 0.5 microns and/or a length in the range of 20 to 300 microns.

7. An electrode as claimed in claim 1 wherein the mass of silicon in the electrically interconnected mass is 70 to 95 percent.

8. An electrode as claimed in claim 1 wherein the intersections comprise a disrupted crystalline or amorphous structure.

9. An electrode as claimed in claim 1 wherein the elongated structures comprise n-type or p-type silicon.

10. An electrode as claimed in claim 1 wherein the elongated structures have a resistivity of 100 to 0.001 Ohm cm.

11. An electrode as claimed in claim 1 wherein the elongated structures have an aspect ratio of greater than 40:

1.

12. An electrode as claimed in claim 1 wherein the elongated structures are substantially straight.

13. An electrode as claimed in claim 1 arranged to form a lithium-ion battery with a second electrode and an electrolyte, wherein the electrolyte at least partially fills pores of the porous composite electrode layer.

14. An electrode for an electrochemical cell, the electrode comprising an electrically interconnected mass comprising:

elongated structures, wherein the elongated structures are electrochemically active such that they are capable of lithium insertion and removal and at least some of the elongated structures cross over each other to provide intersections and a porous structure, and wherein the elongated structures comprise silicon;

wherein the electrically interconnected mass has a percentage pore volume of about 10-30 percent.

15. An electrode as claimed in claim 14 wherein the elongated structures comprise n-type or p-type silicon.

16. An electrode as claimed in claim 14 wherein the elongated structures have a resistivity of 100 to 0.001 Ohm cm.

17. An electrode as claimed in claim 14 wherein the elongated structures have an aspect ratio of greater than 40:

1.

18. An electrode as claimed in claim 14 wherein the elongated structures are straight.

19. An electrode as claimed in claim 14 arranged to form a lithium-ion battery with a second electrode and an electrolyte, wherein the electrolyte at least partially fills pores of the porous composite electrode layer.

20. An electrode for an electrochemical cell, the electrode comprising:

elongated structures, wherein at least some of the elongated structures cross over each other to provide intersections and a porous structure, wherein the elongated structures comprise silicon;

wherein the intersections comprise a disrupted crystalline or amorphous structure which welds the elongated structures to one another.

21. An electrode as claimed in claim 20 wherein the elongated structures comprise n-type or p-type silicon.

22. An electrode as claimed in claim 20 wherein the elongated structures have a resistivity of 100 to 0.001 Ohm cm.

23. An electrode as claimed in claim 20 wherein the silicon comprising fibers have an aspect ratio of greater than 40:

1.

24. An electrode as claimed in claim 20 wherein the elongated structures are straight.

25. An electrode as claimed in claim 20 arranged to form a lithium-ion battery with a second electrode and an electrolyte, wherein the electrolyte at least partially fills pores of the porous composite electrode layer.