Continuous production of binder and collector-less self-standing electrodes for Li-ion batteries by using carbon nanotubes as an additive

Patent metadata

Field	Value
Publication number	US-11569490-B2
Application number	US-202117334647-A
Country	US
Kind code	B2
Filing date	May 28, 2021
Priority date	Jul 31, 2017
Publication date	Jan 31, 2023
Grant date	Jan 31, 2023

Abstract

The present disclosure is directed to a method and apparatus for continuous production of composites of carbon nanotubes and electrode active material from decoupled sources. Composites thusly produced may be used as self-standing electrodes without binder or collector. Moreover, the method of the present disclosure may allow more cost-efficient production while simultaneously affording control over nanotube loading and composite thickness.

First claim

What is claimed is:

1. A method of making a self-standing electrode, the method comprising:
fluidizing an electrode active material; and
co-depositing the fluidized electrode active material and single-walled carbon nanotubes onto a movable porous flexible substrate to form a self-standing electrode that is a composite of the electrode active material and the single-walled carbon nanotubes; and
removing the self-standing electrode from the porous flexible substrate,
wherein the self-standing electrode has a density of 0.75 g/cc to 2.28 g/cc, and
wherein the self-standing electrode comprises 0.1% to 4% by weight carbon nanotubes.

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

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

4. The method of claim 1 , wherein the fluidizing of the electrode active material comprises distributing a carrier gas through, sequentially, a porous frit and a bed of the electrode active material.

5. The method of claim 1 , wherein the density of the self-standing electrode is provided by pressing the self-standing electrode to a selected thickness.

6. The method of claim 5 , wherein the selected thickness is between about 100 microns and 250 microns.

7. The method of claim 6 , wherein the selected thickness is between about 100 microns and 200 microns.

8. The method of claim 5 , wherein the self-standing electrode has an initial thickness prior to pressing, and wherein the selected thickness is from about 40% to 75% of the initial thickness.

9. The method of claim 8 , wherein the selected thickness is from about 45% to 60% of the initial thickness.

10. The method of claim 5 , wherein the self-standing electrode has an initial density prior to pressing, and wherein the density is about 40% to 125% greater than the initial density.

11. The method of claim 10 , wherein the density is about 45% to 90% greater than the initial density.

12. The method of claim 5 , wherein pressing comprises applying between about 7 tons and 10 tons of force to the self-standing electrode.

13. The method of claim 5 , wherein pressing is performed by a rolling press, a calendaring machine, a platen press, or a combination thereof.

14. The method of claim 1 , further comprising cutting the self-standing electrode.

15. The method of claim 1 , wherein fluidizing the electrode active material comprises distributing a carrier gas through a bed of the electrode active material, and wherein the porous flexible substrate comprises a plurality of pores sized to allow passage of the carrier gas therethrough.

16. The method of claim 15 , wherein the plurality of pores are sized to prevent passage of the composite therethrough.

17. The method of claim 15 , wherein the porous flexible substrate comprises a filter or a frit.

18. The method of claim 17 , wherein the filter comprises a material selected from the group consisting of cotton, polyolefins, nylons, acrylics, polyesters, fiberglass, polytetrafluoroethylene, and combinations thereof.

19. The method of claim 15 , wherein the carrier gas comprises argon gas, helium gas, hydrogen gas, nitrogen gas, or a combination thereof.

20. The method of claim 4 , wherein co-depositing the fluidized electrode active material and single-walled carbon nanotubes onto the movable porous flexible substrate comprises passing the carrier gas through the movable porous flexible substrate and removing the carrier gas via an outlet, wherein removing the carrier gas is facilitated by a vacuum source.

Assignees

• Honda Motor Co Ltd
• Nanosynthesis Plus Ltd

Inventors

• Pierce Neal
• Harutyunyan Avetik
• Pigos Elena Mora

Classifications

• H01M4/625

  Carbon or graphite · CPC title

• C01B32/162 Primary

  characterised by catalysts · CPC title

• H01M4/505

  of mixed oxides or hydroxides containing manganese for inserting or intercalating light metals, e.g. LiMn2O4 or LiMn2OxFy · CPC title

• H01M4/583

  Carbonaceous material, e.g. graphite-intercalation compounds or CFx · CPC title

• Y10S977/948

  Energy storage/generating using nanostructure, e.g. fuel cell, battery · CPC title