Carbon nanotube dispersion and method for producing same

Patent metadata

Field	Value
Publication number	US-10468685-B2
Application number	US-201615762938-A
Country	US
Kind code	B2
Filing date	Jul 27, 2016
Priority date	Sep 25, 2015
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

The present disclosure relates to a carbon nanotube dispersion liquid comprising bundle-type carbon nanotubes; a dispersion medium; and a polyvinyl butyral resin having a weight average molecular weight of greater than 50,000, a method for preparing the same, methods for preparing electrode slurry and an electrode using the same, and an electrode and a secondary battery prepared using the carbon nanotube dispersion liquid.

First claim

The invention claimed is:

1. A carbon nanotube dispersion liquid comprising:
bundle-type carbon nanotubes;
a dispersion medium; and
a polyvinyl butyral resin having a weight average molecular weight of greater than 50,000,
wherein dispersed particle diameters of the bundle-type carbon nanotubes have particle size distributions D 50 of 3 μm to 10 μm, D 10 is 1 μm or greater, and D 90 is 30 μm or less.

2. The carbon nanotube dispersion liquid of claim 1 , wherein the polyvinyl butyral resin has a weight average molecular weight of 150,000 or greater.

3. The carbon nanotube dispersion liquid of claim 1 , wherein the polyvinyl butyral resin has a weight average molecular weight of 200,000 or greater.

4. The carbon nanotube dispersion liquid of claim 1 , wherein a content of a hydroxyl group-containing repeating unit of the polyvinyl butyral resin is 15% by weight or greater.

5. The carbon nanotube dispersion liquid of claim 1 , wherein a content of a hydroxyl group-containing repeating unit of the polyvinyl butyral resin is 20% by weight or greater.

6. The carbon nanotube dispersion liquid of claim 1 , wherein the polyvinyl butyral resin comprises a first polyvinyl butyral resin having a weight average molecular weight of greater than 50,000; and a second polyvinyl butyral resin having a lower weight average molecular weight than the first polyvinyl butyral resin.

7. A method for preparing the carbon nanotube dispersion liquid of claim 1 comprising mixing bundle-type carbon nanotubes, and a polyvinyl butyral resin having a weight average molecular weight of greater than 50,000.

8. A method for preparing electrode slurry comprising mixing the carbon nanotube dispersion liquid of claim 1 , an electrode active material and a binder resin.

9. A method for preparing an electrode comprising:
preparing electrode slurry by mixing the carbon nanotube dispersion liquid of claim 1 , an electrode active material and a binder resin; and
forming an electrode using the electrode slurry.

10. Electrode slurry comprising:
the carbon nanotube dispersion liquid of claim 1 ;
an electrode active material; and
a binder resin.

11. An electrode prepared using electrode slurry comprising the carbon nanotube dispersion liquid of claim 1 , an electrode active material and a binder resin.

12. A secondary battery comprising the electrode of claim 11 .

Assignees

• Lg Chemical Ltd

Inventors

• Yoo Houngsik
• Seol Jongheon
• Lee Jong Won
• Kim Dong Hyun
• Kwon Gyemin
• Kim Yelin
• Yoo Jungkeun
• Cho Dong Hyun
• Choy Sang Hoon
• Choi Hyeon
• Kang Kyungyeon
• Woo Jihee

Classifications

• Y10S977/753

  with polymeric or organic binder · CPC title

• H01B1/18

  the conductive material comprising carbon-silicon compounds, carbon or silicon · CPC title

• B82Y40/00

  Manufacture or treatment of nanostructures · CPC title

• Y10S977/742

  Carbon nanotubes, CNTs · CPC title

• C01B2202/36

  Diameter · CPC title