Electrode including nanostructures for rechargeable cells

• US 10,090,512 B2
• Filed: 03/22/2012
• Issued: 10/02/2018
• Est. Priority Date: 05/07/2009
• Status: Active Grant

• Current Assignee: Amprius Technologies Incorporated (Amprius, Inc.)
• Original Assignee: Amprius, Inc.
• Inventors: Cui, Yi, Han, Song, Platshon, Mark C.
• Primary Examiner(s): Mohaddes, Ladan
• Application Number:
  US13/427,681
• Publication Number:
  US 20120183856A1
• Time in Patent Office: 2,385 Days
• Field of Search: None
• 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 2004/022 Electrodes made of one single microscopic fiber
• 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 4/366 as layered products
• CPC Class Codes: H01M 4/66 Selection of materials
• CPC Class Codes: H01M 4/661 Metal or alloys, e.g. alloy coatings H01M4/669 take precedence
• CPC Class Codes: H01M 4/663 containing carbon or carbonaceous materials as conductive part, e.g. graphite, carbon fibres
• CPC Class Codes: H01M 4/75 Wires, rods or strips
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y10T 29/49108 Electric battery cell making

Abstract

A lithium ion battery electrode includes silicon nanowires used for insertion of lithium ions and including a conductivity enhancement, the nanowires growth-rooted to the conductive substrate.

Claims

1. A lithium ion battery electrode comprising:

a conductive substrate; and

silicon-containing nanowires substrate-rooted to the conductive substrate, the silicon-containing nanowires having variable cross-sectional dimensions along the length of the silicon-containing nanowires and having tapered profiles with wider ends and narrower ends such that the silicon-containing nanowires taper from the wider ends to the narrower ends,

wherein one of the ends of each nanowire is substrate-rooted to the conductive substrate to provide conductive attachment and mechanical support to the silicon-containing nanowires with respect to the conductive substrate and the other of the ends of each nanowire is off the conductive substrate and wherein the silicon-containing nanowires further comprise a silicide.

2. The electrode of claim 1, wherein the silicon-containing nanowires each comprise a silicide core and a silicon shell.

3. The electrode of claim 1, wherein the conductive substrate comprises nickel.

4. The electrode of claim 1, wherein the conductive substrate is provided in the form of a structure selected from the group consisting of a mesh, a perforated sheet, a foam, and a felt.

5. The electrode of claim 1, the silicon-containing nanowires comprise substrate-rooted cores and a layer of an electrochemically active material coating the substrate-rooted cores.

6. The electrode of claim 5, wherein the electrochemically active material comprises a material selected from the group of consisting silicon, tin, and germanium.

7. The electrode of claim 6, wherein the substrate-rooted cores comprise a silicide, and wherein the electrochemically active material consists essentially of silicon.

8. The electrode of claim 1, further comprising a shell coating the silicon-containing nanowires.

9. The electrode of claim 8, wherein the shell comprises a carbon-containing material.

10. The electrode of claim 1, wherein the silicon-containing nanowires have an average aspect ratio of at least about ten.

11. The electrode of claim 1, wherein the silicon-containing nanowires have an average cross-sectional dimension of between about 1 nanometer and 10 microns on average.

12. The electrode of claim 1, wherein the silicon-containing nanowires form a layer over the conductive substrate, the layer having porosity of less than about 75 percent.

13. The electrode of claim 1, wherein the silicon-containing nanowires have an average length of at least about 100 micrometers.

16. The electrode of claim 1, wherein the silicon-containing nanowires are growth-rooted to the conductive substrate.

17. The electrode of claim 1, wherein the wider ends of the silicon-containing nanowires are substrate-rooted to the conductive substrate.

18. The electrode of claim 1, wherein the narrower ends of the silicon-containing nanowires are substrate-rooted to the conductive substrate.

19. The electrode of claim 1, wherein the conductive substrate and the silicon-containing nanowires have different compositions.

31. The electrode of claim 12, wherein the silicon-containing nanowires have an average length of at least about 100 micrometers.

32. A lithium ion battery comprising:

a first electrode comprising the electrode of claim 1;

a second electrode; and

an electrolyte.

14. A lithium ion battery electrode comprising:

a conductive substrate; and

silicon-containing nanowires substrate-rooted to the conductive substrate, the silicon-containing nanowires having variable cross-sectional dimensions along the length of the silicon-containing nanowires and having tapered profiles with wider ends and narrower ends such that the silicon-containing nanowires taper from the wider ends to the narrower ends,

wherein one of the ends of each nanowire is substrate-rooted to the conductive substrate to provide conductive attachment and mechanical support to the silicon-containing nanowires with respect to the conductive substrate and the other of the ends of each nanowire is off the conductive substrate and wherein the silicon-containing nanowires consist essentially of silicon.

15. The electrode of claim 14, wherein the average cross-sectional dimension of the wider ends is below the silicon fracture limit.

30. The electrode of claim 14, wherein the silicon-containing nanowires have an average aspect ratio of at least about ten.

20. A lithium ion battery electrode comprising:

a conductive substrate; and

silicon-containing nanowires substrate-rooted to the conductive substrate, the silicon-containing nanowires having variable cross-sectional dimensions along the length of the silicon-containing nanowires and having tapered profiles with wider ends and narrower ends such that the silicon-containing nanowires taper from the wider ends to the narrower ends,

wherein one of the ends of each nanowire is substrate-rooted to the conductive substrate to provide conductive attachment and mechanical support to the silicon-containing nanowires with respect to the conductive substrate and the other of the ends of each nanowire is off the conductive substrate and wherein the conductive substrate has a conductivity of at least 10³ S/m.

21. The electrode of claim 20, wherein the silicon-containing nanowires further comprise a carbide.

22. The electrode of claim 20, wherein the silicon-containing nanowires each comprise a silicide core and a silicon shell.

23. The electrode of claim 20, the silicon-containing nanowires comprise substrate-rooted cores and a layer of an electrochemically active material coating the substrate-rooted cores.

24. The electrode of claim 23, wherein the electrochemically active material comprises a material selected from the group of consisting silicon, tin, and germanium.

25. The electrode of claim 24, wherein the substrate-rooted cores comprise a silicide, and wherein the electrochemically active material consists essentially of silicon.

26. The electrode of claim 23, wherein the substrate-rooted cores comprise a silicide.

27. The electrode of claim 20, wherein the wider ends of the nanowires are substrate-rooted to the conductive substrate.

28. The electrode of claim 20, wherein the narrower ends of the nanowires are substrate-rooted to the conductive substrate.

29. A lithium ion battery comprising:

a first electrode comprising the electrode of claim 20;

a second electrode; and

an electrolyte.