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

• US 20100178565A1
• Filed: 07/17/2008
• Published: 07/15/2010
• Est. Priority Date: 07/17/2007
• Status: Active Grant

• Current Assignee: Nexeon Limited
• Original Assignee: Nexeon Limited
• Inventors: Green, Mino
• Granted Patent: US 8,940,437 B2
• Time in Patent Office: Days
• US Class Current: 429/231.950
• CPC Class Codes: H01M 10/52 Removing gases inside the secondary cell, e.g. by absorption vent plugs or other mechanical arrangements for facilitating escape of gases H01M50/30
• CPC Class Codes: H01M 2004/027 Negative electrodes
• CPC Class Codes: H01M 4/0492 Chemical attack of the support material
• CPC Class Codes: H01M 4/134 Electrodes based on metals, Si or alloys
• 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: 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 117/102 for forming a platelet shape or a small diameter, elongate, generally cylindrical shape [e.g., whisker, fiber, needle, filament]
• CPC Class Codes: Y10T 29/49108 Electric battery cell making
• CPC Class Codes: Y10T 428/2982 Particulate matter [e.g., sphere, flake, etc.]

Abstract

Pillared particles of silicon or silicon-comprising material and a method of fabricating the same are disclosed. These particles may be used to create both a composite anode structure with a polymer binder, a conductive additive and a metal foil current collector, and an electrode structure. The structure of the particles overcomes the problems of charge/discharge capacity loss.

Claims

1. A particle comprising silicon, the particle having a particle core and an array of silicon-comprising pillars extending therefrom.

2. A particle as claimed in claim 1 where in the array is regular.

3. A particle as claim in claim 1 wherein the array is irregular.

4. A particle as claimed in claim 1 in which the pillars have a first dimensions in the range 0.08 to 0.70 microns.

5. A particle as claimed in claim 4 in which the pillars have a second dimension in the range 4 to 100 microns.

6. A particle as claimed in claim 1 in which the pillars have an aspect ratio of greater than 20:

1.

7. A particle as claimed in claim 1 in which the pillars have a substantially circular cross-section.

8. A particle as claimed in claim 1 in which the pillars have a substantially non-circular cross-section.

9. A particle as claimed in claim 1 in which the particle and/or pillars comprise undoped silicon, doped silicon or a silicon germanium mixture.

10. A particle as claimed in claim 1 wherein the silicon content is 90.00 to 99.95% by mass, preferably 90.0 to 99.5%.

14. A particle as claimed in claim 1 having a first dimension of 10 μ

m to 1 mm, preferably 20 μ

m to 150 μ

m, more preferably 25 μ

m to 75 μ

m.

16. A particle as claimed in claim 1 wherein the fraction of the surface area of the particle core occupied by pillars is 0.10 to 0.50, preferably 0.20 to 0.40 and more preferable 0.25 to 0.35.

20. An electrode containing particles as defined in claim 1 as one of its active materials.

21. An electrode as claimed in claim 20 which uses copper as a current collector.

22. An electrode as claimed in claim 20 in which the electrode is an anode.

23. An electrochemical cell containing an electrode as claimed in claim 20.

24. An electrochemical cell as claimed in claim 23 in which the cathode comprises a lithium-containing compound capable of releasing and reabsorbing lithium ions as its active material.

25. An electrochemical cell as claimed in claim 24 in which the cathode comprises lithium-based metal oxide, sulphide or phosphate as its active material.

27. An electrode as claimed in claim 22 in which the particles are part of a composite film.

31. A device powered by a cell as claimed in claim 23.

11-13. -13. (canceled)

15. (canceled)

17-19. -19. (canceled)

26. (canceled)

28-30. -30. (canceled)

32-36. -36. (canceled)