Carbon nanotube dispersion liquid and manufacturing method thereof

• US 10,686,185 B2
• Filed: 08/26/2016
• Issued: 06/16/2020
• Est. Priority Date: 09/25/2015
• Status: Active Grant

• Current Assignee: LG Chem Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Yoo, Houngsik, Lee, Jong Won, Kim, Dong Hyun, Kwon, Gyemin, Ahn, Byoung Hoon, Kim, Yelin, Choy, Sang Hoon, Choi, Hyeon, Yoo, Jungkeun
• Primary Examiner(s): Laios, Maria
• Application Number:
  US15/760,066
• Publication Number:
  US 20190051887A1
• Time in Patent Office: 1,390 Days
• Field of Search: None
• CPC Class Codes: C01B 32/174 Derivatisation; Solubilisation; Dispersion in solvents
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 4/0404 by coating on electrode collectors
• CPC Class Codes: H01M 4/139 Processes of manufacture
• CPC Class Codes: H01M 4/62 Selection of inactive substances as ingredients for active masses, e.g. binders, fillers
• CPC Class Codes: H01M 4/625 Carbon or graphite
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

The present disclosure relates to a carbon nanotube dispersion including entangled-type carbon nanotubes, a dispersion medium, and partially hydrogenated nitrile rubber having a residual double bond (RDB) value of 0.5% by weight to 40% by weight calculated according to the following Mathematical Formula 1, wherein dispersed particle diameters of the carbon nanotubes have particle size distribution D₅₀ of 2 μm to 5 μm, a method for preparing the same, and methods for preparing electrode slurry and an electrode using the same.

Claims

1. A carbon nanotube dispersion liquid comprising:

entangled-type carbon nanotubes;

a dispersion medium; and

partially hydrogenated nitrile rubber having a residual double bond (RDB) value of 0.5% by weight to 40% by weight calculated according to the following Mathematical Formula 1,

wherein dispersed particle diameters of the carbon nanotubes have particle size distribution D₅₀ of 2 μ

m to 5 μ

m;

RDB (% by weight)=BD weight/(BD weight+HBD weight)×

100  

 

[Mathematical Formula 1]

in Mathematical Formula 1, BD is defined as a conjugated diene-derived structure unit and HBD is defined as a hydrogenated conjugated diene-derived structure unit.

2. The carbon nanotube dispersion liquid of claim 1, wherein the partially hydrogenated nitrile rubber comprises an α

,β

-unsaturated nitrile-derived structure unit, a conjugated diene-derived structure unit and a hydrogenated conjugated diene-derived structure unit.

3. The carbon nanotube dispersion liquid of claim 2, comprising the α

,β

-unsaturated nitrile-derived structure unit in 20% by weight to 50% by weight with respect to a total weight of the rubber.

4. The carbon nanotube dispersion liquid of claim 1, comprising a carbon nanotube complex in which the partially hydrogenated nitrile rubber is introduced to surfaces of the carbon nanotubes.

5. The carbon nanotube dispersion liquid of claim 1, wherein the dispersed particle diameters of the entangled-type carbon nanotubes have a particle size distribution such that D₅₀ is from 2 μ

m to 5 μ

m, D₁₀ is from 0.5 μ

m to 1.5 μ

m and D₉₀ is from 6 μ

m to 10 μ

m.

6. The carbon nanotube dispersion liquid of claim 1, wherein the partially hydrogenated nitrile rubber comprises a unit of the following Chemical Formula 1, a unit of the following Chemical Formula 2 and a unit of the following Chemical Formula 3:

7. The carbon nanotube dispersion liquid of claim 1, wherein the partially hydrogenated nitrile rubber has a weight average molecular weight of 10,000 g/mol to 700,000 g/mol.

8. The carbon nanotube dispersion liquid of claim 1, wherein the partially hydrogenated nitrile rubber has a polydispersity index PDI (Mw/Mn) ratio of 2 to 6.

9. A method for preparing the carbon nanotube dispersion liquid of claim 1, comprising mixing the entangled-type carbon nanotubes, the dispersion medium and the partially hydrogenated nitrile rubber.

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

11. A method for preparing an electrode comprising:

preparing an 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.