Carbon nanotube water dispersion, conductive film, electrode, and solar cell and method of producing same

Patent metadata

Field	Value
Publication number	US-12415730-B2
Application number	US-202118043909-A
Country	US
Kind code	B2
Filing date	Aug 25, 2021
Priority date	Sep 24, 2020
Publication date	Sep 16, 2025
Grant date	Sep 16, 2025

Abstract

A carbon nanotube water dispersion contains single-walled carbon nanotubes, acetylene black, a dispersant, and water. The content ratio of the single-walled carbon nanotubes and the acetylene black in the carbon nanotube water dispersion, in terms of a mass ratio of acetylene black/single-walled carbon nanotubes, is 1.4 or less.

First claim

The invention claimed is:

1. A carbon nanotube water dispersion comprising: one or more single-walled carbon nanotubes; acetylene black; a dispersant; and water, wherein a content ratio of the single-walled carbon nanotubes and the acetylene black, in terms of a mass ratio of acetylene black/single-walled carbon nanotubes, is 1.4 or less, and wherein
a content of the dispersant per 100 parts by mass of the single-walled carbon nanotubes is 50 parts by mass or more,
a content of the single-walled carbon nanotubes in the carbon nanotube water dispersion is 0.5 mass % or more,
BET specific surface area of the single-walled carbon nanotubes is 400 m 2 /g or more and 1,600 m 2 /g or less and BET specific surface area of the acetylene black is 30 m 2 /g or more and 150 m 2 /g or less.

2. The carbon nanotube water dispersion according to claim 1 , further comprising a thickener.

3. The carbon nanotube water dispersion according to claim 2 , wherein the dispersant and the thickener are each formed of a non-ionic polymer.

4. The carbon nanotube water dispersion according to claim 1 , wherein the dispersant is a copolymer of styrene and methoxy polyethylene glycol methacrylate.

5. A conductive film obtained using the carbon nanotube water dispersion according to claim 1 .

6. An electrode comprising the conductive film according to claim 5 .

7. The electrode according to claim 6 , wherein the electrode is a counter electrode.

8. A solar cell comprising the electrode according to claim 6 .

9. A method of producing a solar cell having a first electrode, an electrolyte layer, and a second electrode in a stacked arrangement in stated order, comprising:
a step of applying the carbon nanotube water dispersion according claim 1 onto a substrate and performing drying thereof to form a conductive film and form a first electrode that includes the conductive film; and
a step of using an electrolyte solution containing a polar aprotic substance as a solvent to form an electrolyte layer between the first electrode and a second electrode.

10. The method of producing a solar cell according to claim 9 , wherein the dispersant that is contained in the carbon nanotube water dispersion is soluble in the solvent that is contained in the electrolyte solution.

11. The method of producing a solar cell according to claim 9 , wherein the carbon nanotube water dispersion further contains a thickener, and the thickener is insoluble in the solvent that is contained in the electrolyte solution.

12. The method of producing a solar cell according to claim 9 , wherein the polar aprotic substance is one or more selected from the group consisting of acetonitrile, γ-butyrolactone, 3-methoxypropionitrile, and triethylene glycol monomethyl ether.

Assignees

• Zeon Corp

Inventors

• Oota Ryuji

Classifications

• H10F77/211

  for photovoltaic cells · CPC title

• C01B32/159

  single-walled · CPC title

• C01B32/174 Primary

  Derivatisation; Solubilisation; Dispersion in solvents · CPC title

• H10K30/821

  comprising carbon nanotubes · CPC title

• H10K85/221

  Carbon nanotubes · CPC title