Cohesive assembly of carbon and its application

Patent metadata

Field	Value
Publication number	US-2017194629-A1
Application number	US-201715444631-A
Country	US
Kind code	A1
Filing date	Feb 28, 2017
Priority date	Jun 20, 2011
Publication date	Jul 6, 2017
Grant date	—

Abstract

Cohesive carbon assemblies are prepared by obtaining a carbon starting material in the form of powder, particles, flakes, or loose agglomerates, dispersing the carbon in a selected organic solvent by mechanical mixing and/or sonication, and substantially removing the organic solvent, typically by evaporation, whereby the cohesive assembly of carbon is formed. The method is suitable for preparing free-standing, monolithic assemblies of carbon nanotubes in the form of films, wafers, or discs, having high carbon packing density and low electrical resistivity. The method is suitable for preparing adherent cohesive carbon assemblies on substrates comprising various materials. The assemblies have various potential applications, such as electrodes or current collectors in electrochemical capacitors, fuel cells, and batteries, or as electromagnetic interference shielding materials.

First claim

What is claimed:

1 . A method of preparing a cohesive carbon assembly comprising:
(a) obtaining a carbon starting material in the form of powder, particles, flakes, or loose agglomerates; (b) dispersing the carbon starting material in an organic solvent comprising toluene, o-dichlorobenzene (ODCB), isopropyl alcohol (IPA), N,N-dimethylformamide (DMF), benzene, chlorobenzene, m-dichlorobenzene, 1,2,4-trichlorobenzene, bromobenzene, m-dibromobenzene, o-dibromobenzene, toluene, o-xylene, m-xylene, p-xylene, 1,2-dichloroethane, 1,2-dibromoethane, chloroform, formamide, N-methylformamide; N-vinylformamide; N-(phenethyl)formamide, N,N-diethylformamide, N,N-bis(1-methylethyl)formamide, dimethyl sulfoxide, or any combinations thereof in a prescribed ratio to form a dispersion; and (c) substantially removing the organic solvent in a controlled manner, whereby the cohesive carbon assembly is formed.

2 . The method of claim 1 , wherein the carbon starting material is a carbon material selected from the group consisting of carbon nanotubes, graphene, graphite, expanded graphite, exfoliated graphite, amorphous carbon, and any combinations thereof.

3 . The method of claim 2 , wherein the carbon nanotubes are single-walled carbon nanotubes, double-walled carbon nanotubes, multi-walled carbon nanotubes, or any combination thereof.

4 . The method of claim 2 , wherein the Raman G/D ratio of the formed cohesive carbon assembly is about the same or greater than the Raman G/D ratio of the carbon starting material.

5 . The method of claim 1 , wherein the organic solvent is toluene.

6 . The method of claim 1 , wherein the organic solvent is o-dichlorobenzene.

7 . The method of claim 1 , wherein the carbon starting material is dispersed in the organic solvent in the presence of mechanical agitation in step (b).

8 . The method of claim 7 , wherein the mechanical agitation comprises sonication, mechanical stirring, or a combination thereof.

9 . The method of claim 1 , wherein the carbon starting material is single-walled carbon nanotubes, the organic solvent is o-dichlorobenzene or toluene, and the ratio of carbon starting material and the organic solvent is about 0.1 to about 20 mg carbon per gram of the organic solvent.

10 . The method of claim 1 , wherein the organic solvent is substantially free of a binding material.

11 . The method of claim 1 , further comprising collecting the removed organic solvent.

12 . The method of claim 1 , further comprising applying the dispersion to a hydrophobic surface after step (b) and before step (c).

13 . The method of claim 12 , wherein the hydrophobic surface comprises a dimethyl organosilane, a fluorinated dimethyl organosilane, a fluorinated polymer, or Teflon.

14 . The method of claim 12 , wherein the dispersion is applied to the hydrophobic surface by casting.

15 . The method of claim 1 , further comprising applying the dispersion to a hydrophilic surface after step (b) and before step (c).

16 . The method of claim 15 , wherein the hydrophilic surface is selected from the group consisting of metal, glass, silicon, plastic, ceramic, and any combinations thereof.

17 . The method of claim 15 , wherein the hydrophilic surface is a metal substrate selected from the group consisting of aluminum, nickel, copper, gold, silver, platinum, and any combination thereof.

18 . The method of claim 15 , wherein the dispersion is applied to the hydrophilic surface by spin-coating, dip-coating, flow-coating, spray coating, casting, or any combination thereof.

19 . A cohesive carbon assembly on a metal substrate prepared by the method of claim 17 .

20 . The cohesive carbon assembly on a metal substrate of claim 19 , wherein the carbon starting material is carbon nanotubes, and the organic solvent is o-dichlorobenzene, toluene, or a combination thereof.

Assignees

• Yazaki Corp

Inventors

• Raychaudhuri Satyabrata
• Yan Yongan
• Grigorian Leonid

Classifications

• C01B32/159

  single-walled · CPC title

• H01M4/8878

  Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body · CPC title

• H01M2220/20

  Batteries in motive systems, e.g. vehicle, ship, plane · CPC title

• Y10S977/948

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

• H01M4/0471

  involving thermal treatment, e.g. firing, sintering, backing particulate active material, thermal decomposition, pyrolysis · CPC title