Self standing electrodes and methods for making thereof

Patent metadata

Field	Value
Publication number	US-10658651-B2
Application number	US-201715665171-A
Country	US
Kind code	B2
Filing date	Jul 31, 2017
Priority date	Jul 31, 2017
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

The present disclosure relates to a method of making a composite product that may be used as a flexible electrode. An aerosolized mixture of nanotubes and an electrode active material is collected on a porous substrate, such as a filter, until it reaches a desired thickness. The resulting self-standing electrode may then be removed from the porous substrate and may operate as a battery electrode.

First claim

What is claimed is:

1. A method of producing a self-standing electrode, the method comprising:
aerosolizing an electrode active material to produce an aerosolized electrode active material powder;
contacting the aerosolized electrode active material powder with single-walled carbon nanotubes in a carrier gas to form a mixture of the single-walled carbon nanotubes and the aerosolized electrode active material powder;
collecting the mixture on a porous surface, wherein at least a portion of the carrier gas passes through the porous surface; and
removing the mixture from the porous surface, to form the self-standing electrode material that is a composite of the single-walled carbon nanotubes and the electrode active material, wherein the self-standing electrode is free of binder and metal-based current collector, and wherein the self-standing electrode comprises 0.1% to 4% by weight carbon nanotubes and has a density of 0.75 g/cc to 2.28 g/cc.

2. The method of claim 1 , wherein the aerosolizing of the electrode active material comprises distributing an aerosolizing gas through a first porous frit and a bed of an electrode active material, in an aerosolizing reactor, to produce the aerosolized electrode active material powder.

3. The method of claim 1 , further comprising providing the single-walled carbon nanotubes from a carbon nanotube synthesis reactor.

4. The method of claim 1 , wherein the porous surface is comprised by a porous frit in a collection chamber.

5. The method of claim 1 , wherein the electrode active material is selected from graphite, hard carbon, lithium metal oxides, and lithium iron phosphate.

6. The method of claim 1 , further comprising synthesizing the single-walled carbon nanotubes in a carbon nanotube synthesis reactor.

7. The method of claim 6 , wherein the contacting of the aerosolized electrode active material powder with the single-walled carbon nanotubes occurs downstream of the carbon nanotube synthesis reactor and upstream of the porous surface.

8. A method of producing a self-standing electrode, the method comprising:
providing an aerosolized mixture of carbon nanotubes and an electrode active material powder;
providing at least a first porous substrate;
directing the aerosolized mixture toward the first porous substrate;
collecting the mixture on the first porous substrate; and
removing the mixture from the first porous substrate to form the self-standing electrode, wherein the self-standing electrode is free of binder and metal-based current collector, and wherein the self-standing electrode comprises 0.1% to 4% by weight carbon nanotubes and has a density of 0.75 g/cc to 2.28 g/cc.

9. The method of claim 8 wherein the aerosolized mixture comprises at least one carrier gas that passes through the porous substrate as the mixture is collected on the porous substrate.

10. The method of claim 9 wherein the mixture is collected on the porous substrate until the collected mixture comprises a thickness of up to 750 μm.

11. The method of claim 10 wherein the mixture is collected on the porous substrate until the collected mixture comprises a thickness of 100 μm to 450 μm.

12. The method of claim 10 wherein the self-standing electrode has a density of 0.75 g/cc to 2.0 g/cc.

13. The method of claim 12 wherein the self-standing electrode has a density of 0.95 g/cc to 1.60 g/cc.

14. The method of claim 8 further comprising treating the self-standing electrode to increase the density of the self-standing electrode, wherein the treated self-standing electrode has a density that is 40% to 125% greater than the density of the untreated self-standing electrode.

15. The method of claim 14 wherein the treated self-standing electrode has a density that is 45% to 90% greater than the density of the untreated self-standing electrode.

16. The method of claim 14 wherein the treated self-standing electrode has a thickness that is 40% to 75% of the thickness of the untreated self-standing electrode.

17. The method of claim 8 wherein the step of providing an aerosolized mixture of carbon nanotubes and an electrode active material powder comprises:
providing a first aerosolized stream comprising the carbon nanotubes and at least one carrier gas;
providing a second aerosolized stream comprising the electrode active material powder and at least one carrier gas; and
mixing the first aerosolized stream and the second aerosolized stream to provide the aerosolized mixture.

18. The method of claim 17 wherein the first aerosolized stream comprises a product stream exiting from a nanotube synthesis reactor.

19. The method of claim 18 further comprising:
providing a carbon source in the nanotube synthesis reactor;
growing carbon nanotubes in the presence of a carrier gas;
transferring the product stream comprising the carbon nanotubes and the carrier gas out of the nanotube synthesis reactor as the first aerosolized stream.

20. The method of claim 8 further comprising:
redirecting the mixture toward a second porous substrate after the collected mixture formed on the first porous substrate comprises a first desired thickness; and
collecting the mixture on the second porous substrate until a second collected mixture comprises a second desired thickness.

21. The method of claim 20 wherein the step of redirecting the mixture further comprises:
measuring a pressure drop across a first porous surface of the first porous substrate; and
redirecting the mixture toward the second porous substrate after a pressure drop associated with the first desired thickness is measured across the first porous surface.

22. The method of claim 8 wherein the self-standing electrode comprises 0.2% to 3% by weight carbon nanotubes.

23. The method of claim 22 wherein the self-standing electrode comprises 0.75% to 2% by weight carbon nanotubes.

24. The method of claim 8 wherein the self-standing electrode consists essentially of the carbon nanotubes and the electrode active material powder.

25. The method of claim 8 wherein the self-standing electrode consists of the carbon nanotubes and the electrode active material powder.

26. The method of claim 8 wherein the nanotubes comprises single-walled carbon nanotubes.

27. The method of claim 26 wherein the electrode active material powder comprises graphite.

28. The method of claim 26 wherein the electrode active material powder comprises a metal oxide.

29. The method of claim 28 wherein the electrode active material powder comprises LiNiMnCoO 2 .

30. The method of claim 26 wherein the self-standing electrode comprises a webbed arrangement of the carbon nanotubes with the electrode active material embedded within the carbon nanotube web.

31. The method of claim 30 wherein the self-standing electrode is flexible.

Assignees

• Honda Motor Co Ltd

Inventors

• Pierce Neal
• Harutyunyan Avetik

Classifications

• B01J19/00

  Chemical, physical or physico-chemical processes in general; Their relevant apparatus · CPC title

• H01M4/525

  of mixed oxides or hydroxides containing iron, cobalt or nickel for inserting or intercalating light metals, e.g. LiNiO2, LiCoO2 or LiCoOxFy · CPC title

• H01M4/5825

  Oxygenated metallic salts or polyanionic structures, e.g. borates, phosphates, silicates, olivines · CPC title

• H01M10/0525

  Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries · CPC title

• H01M4/043

  involving compressing or compaction · CPC title