Carbon nanotube dispersion and method for producing the same

Abstract

The present invention relates to a carbon nanotube dispersion comprising carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing a compound represented by chemical formula 1, and a solvent, and a method for producing the same. The details of the compound represented by chemical formula 1 are as defined in the specification.

Description

[Technical Field]

[0001] This application claims the benefit of priority under Korean Patent Application No. 10-2023-0099772 dated July 31, 2023, and Korean Patent Application No. 10-2024-0100273 dated July 29, 2024, and incorporates all the contents disclosed in the documents of the said Korean patent applications as part of this specification.

[0002] This invention relates to a carbon nanotube dispersion and a method for producing the same. [Background technology]

[0003] As technological development and demand for mobile devices increase, the demand for rechargeable batteries as an energy source is surging. Among these rechargeable batteries, lithium-ion batteries, which have high energy density and voltage, long cycle life, and low self-discharge rates, have been commercialized and are widely used. Furthermore, research is actively being conducted on methods to improve electrode density and manufacture electrodes with even higher energy density per unit volume for such high-capacity lithium-ion batteries.

[0004] Generally, high-density electrodes are formed by molding electrode active material particles, which have a size of several micrometers to tens of micrometers, using high-pressure pressing. However, during the molding process, the particles may deform, and the space between the particles may decrease, which can easily reduce the permeability of the electrolyte.

[0005] To solve the aforementioned problems, conductive materials with excellent electrical conductivity and strength are used in the manufacture of electrodes. These conductive materials are positioned between the electrode active materials, and even during the molding process, they maintain fine pores between the active material particles, allowing the electrolyte to easily penetrate, resulting in excellent electrical conductivity and reduced resistance within the electrode. Among such conductive materials, the use of carbon nanotubes, which are fibrous carbon-based conductive materials that can further reduce electrode resistance by forming electrical conductive paths within the electrode, is increasing.

[0006] Carbon nanotubes, a type of fine carbon fiber, are tubular carbon fibers with a diameter of 1 μm or less. Due to their unique structure, they possess high conductivity, tensile strength, and heat resistance, making them promising for application and practical use in various fields. However, carbon nanotubes have a high specific surface area, which leads to poor dispersibility due to strong van der Waals forces between them, resulting in aggregation.

[0007] To address these issues, methods have been proposed to disperse carbon nanotubes in a dispersion medium through mechanical dispersion processes such as ultrasonic treatment. However, mechanical dispersion methods have problems such as the carbon nanotubes aggregating as soon as ultrasonic irradiation ends, or aggregating again over time after dispersion.

[0008] Therefore, there is a need to develop a method for producing a carbon nanotube dispersion that has improved dispersibility, low viscosity, and suppressed viscosity increase over time. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] U.S. Patent Publication No. 2020-0309771 (October 1, 2020) [Overview of the project] [Problems that the invention aims to solve]

[0010] The object of the present invention is to provide a carbon nanotube dispersion that comprises carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing a compound represented by the following chemical formula 1, and a solvent, which exhibits excellent dispersibility, low viscosity of the dispersion and particle size of the dispersed particles, and minimal change in viscosity over time.

[0011] [ka]

[0012] In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and each is independently a substituted or unsubstituted C6-C30 aryl group. Ar2 to Ar5 are either identical or different from each other, and each is independently substituted or unsubstituted C6 to C30 arylene groups. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

[0013] Another object of the present invention is to provide a method for producing the carbon nanotube dispersion. [Means for solving the problem]

[0014] One embodiment of the present invention provides a carbon nanotube dispersion comprising carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing a compound represented by the following chemical formula 1, and a solvent.

[0015] [ka]

[0016] In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and each is independently a substituted or unsubstituted C6-C30 aryl group. Ar2 to Ar5 are either identical or different from each other, and each is independently substituted or unsubstituted C6 to C30 arylene groups. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

[0017] Ar1 and Ar6 in the aforementioned chemical formula 1 may each be represented by the following chemical formula 2, Ar2 and Ar5 in the aforementioned chemical formula 1 may each be represented by the following chemical formula 3, and Ar3 and Ar4 in the aforementioned chemical formula 1 may each be represented by the following chemical formula 4.

[0018] [ka]

[0019] In the aforementioned chemical formula 2, R1 to R6 are either identical or different from each other, and each is independently a site that can be linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and one of R1 to R6 is a site that can be linked to an azo group of chemical formula 1. In the aforementioned chemical formula 3, R7 to R12 are either identical or different from each other, and each is independently a site that can be linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and at least two of R7 to R12 are sites that can be linked to azo group of chemical formula 1. In the aforementioned chemical formula 4, R13 to R20 are either identical or different to each other, and each is independently a hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; a site linked to the azo group of chemical formula 1; or a site linked to L1 of chemical formula 1, wherein at least one of R13 to R20 is a site linked to the azo group of chemical formula 1, and at least one of the other R13 to R20 (excluding the sites linked to the azo group of chemical formula 1) is a site linked to L1 of chemical formula 1.

[0020] Among the R1 to R6 of Chemical Formula 2, excluding the part linked to the azo group of Chemical Formula 1, at least one may be a sulfonate group; among the R7 to R12 of Chemical Formula 3, excluding the part linked to the azo group of Chemical Formula 1, at least one may be a sulfonate group; and among the R13 to R20 of Chemical Formula 4, excluding the part linked to the azo group and L1 of Chemical Formula 1, at least one may be a sulfonate group.

[0021] The second dispersant may contain the compound represented by the following chemical formula 1-1.

[0022] [ka]

[0023] In the above chemical formula 1-1, R1-R5, R7-R10, and R13-R18 are either identical or different from each other, and each is independently hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; or nitro group.

[0024] The carbon nanotube dispersion can contain 0.05 to 5 parts by weight of carbon nanotubes based on 100 parts by weight of the carbon nanotube dispersion.

[0025] The BET specific surface area of ​​the carbon nanotube is 800 to 2,000 m². 2 / g is also acceptable.

[0026] The first dispersant may be one or more selected from the group consisting of polyvinylpyrrolidone, polyacrylic acid hydrazide, poly-N-vinyl-5-methoxazolidon, N-alkyl polyimine, N-acetyl polyimine, polyacrylamide, poly-L-lysine hydrobromide, benzyl-dodecyl-dimethylammonium chloride, and polyethyleneimine.

[0027] The first dispersant may be included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the carbon nanotube dispersion.

[0028] The second dispersant may be included in an amount of 0.001 to 9 parts by weight based on 100 parts by weight of the carbon nanotube dispersion.

[0029] The first and second dispersants may be present in a weight ratio of 100:10 to 100:90.

[0030] The carbon nanotube dispersion may have an initial viscosity of 1 to 10 Pa·s, as measured at 25°C and 1 rpm.

[0031] The carbon nanotube dispersion may have a viscosity increase rate of 15% or less, as represented by the following formula (1).

[0032] [Formula 1] Viscosity increase rate (%) = {(Viscosity measured after being left at 25°C for one week - initial viscosity) / initial viscosity} × 100 Another embodiment of the present invention provides a method for producing a carbon nanotube dispersion, comprising the steps of (1) mixing carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing the compound represented by chemical formula 1, and a solvent to produce a primary dispersion of carbon nanotubes, and (2) dispersing the primary dispersion of carbon nanotubes to produce a secondary dispersion of carbon nanotubes. [Effects of the Invention]

[0033] The carbon nanotube dispersion according to the present invention, by using a first dispersant containing nitrogen atoms together with a second dispersant containing the compound represented by the chemical formula 1, exhibits a small change in viscosity over time, exhibits relatively low viscosity, and has the characteristic of having a small particle size due to the uniform and effective dispersion of carbon nanotubes, despite using carbon nanotubes with a large specific surface area. [Best Mode for Carrying Out the Invention]

[0034] The following describes in detail some embodiments of the present invention. Prior to this, terms and words used in this specification and claims should not be interpreted restrictively in their usual or dictionary sense, but rather in a sense that is consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors can appropriately define the concepts of terms in order to best describe their invention. Accordingly, the configurations described in the examples described herein are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and it should be understood that there are various equivalents and modifications that can substitute for them at the time of filing this application.

[0035] In this specification, the term "substitution" means that a hydrogen atom bonded to a carbon atom of a compound is replaced by another substituent, and the position of substitution is not limited to a position where a hydrogen atom can be substituted, i.e., any position where a substituent can be substituted, and if two or more substituents are substituted, the two or more substituents may be the same or different.

[0036] In this specification, "substituted or unsubstituted" means that a substituent is substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; halogens; cyano groups; linear or branched alkyl groups of C1-C60; linear or branched alkenyl groups of C2-C60; linear or branched alkynyl groups of C2-C60; monocyclic or polycyclic cycloalkyl groups of C3-C60; monocyclic or polycyclic heterocycloalkyl groups of C2-C60; monocyclic or polycyclic aryl groups of C6-C60; monocyclic or polycyclic heteroaryl groups of C2-C60; alkylamine groups of C1-C20; monocyclic or polycyclic arylamine groups of C6-C60; and monocyclic or polycyclic heteroarylamine groups of C2-C60, or that a substituent is substituted or unsubstituted with one or more substituents selected from the above-mentioned substituents linked together.

[0037] Throughout this specification, when a part of a section "includes" a component, this means, unless otherwise stated, that it does not exclude other components, but rather that other components may be included.

[0038] Throughout this specification, "%" means weight percent unless otherwise explicitly indicated.

[0039] In this specification, the average particle size "D 50 " refers to a particle size corresponding to a volume accumulation of 50%. 50 This can be measured, for example, using the laser diffraction method. The laser diffraction method generally allows for the measurement of particle sizes ranging from the submicron region to several millimeters, and yields results with high reproducibility and high resolution.

[0040] In this specification, "specific surface area" is measured by the BET method (Brunauer-Emmett-Teller Analysis), and specifically, it is calculated from the amount of nitrogen gas adsorbed at liquid nitrogen temperature (77K) using BELSORP-mino II from BEL Japan.

[0041] Carbon nanotube dispersion The carbon nanotube dispersion according to the present invention comprises carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing the compound represented by the chemical formula 1, and a solvent. The components of the carbon nanotube dispersion according to the present invention will be described in detail below.

[0042] (1) Carbon nanotubes The term "carbon nanotube" as used in this invention refers to a secondary structure formed by the aggregation of carbon nanotube units so as a whole or partially as a bundle type, wherein the carbon nanotube units have a graphite sheet with a cylindrical shape of nanoscale diameter, and sp 2 It has a bonding structure. In this case, depending on the angle and structure in which the graphite surface is wound, it can exhibit conductive or semiconductor properties. Carbon nanotube units are classified into single-walled carbon nanotubes (SWCNTs), double-walled carbon nanotubes (DWCNTs), and multi-walled carbon nanotubes (MWCNTs) according to the number of bonds forming the wall.

[0043] In this invention, the term "bundle type" refers to a secondary shape in which multiple carbon nanotube units are arranged in a bundle or rope form, unless otherwise specified, in which the longitudinal axes of the units are substantially aligned in the same orientation, or are twisted or tangled after being arranged. The term "non-bundle type" or "entangled type" refers to a form in which the carbon nanotube units do not have a fixed shape such as a bundle or rope form, but are tangled.

[0044] Carbon nanotubes have high conductivity, but they also have high cohesiveness due to van der Waals forces that occur between them. When conductive materials aggregate, it becomes difficult to properly form conductive paths within the electrode, and more conductive material is used to increase conductivity, which relatively reduces the amount of active material and can actually decrease the performance of the electrode, such as its capacity. Therefore, there have been difficulties in commercializing carbon nanotubes as conductive materials.

[0045] The carbon nanotube dispersion according to the present invention contains a first dispersant containing nitrogen atoms and a second dispersant containing the compound represented by the chemical formula 1. This significantly reduces the initial viscosity of the carbon nanotube dispersion, suppresses viscosity changes over time, and simultaneously maintains a low particle size of the dispersed particles.

[0046] A carbon nanotube dispersion according to one embodiment of the present invention may contain, but is not limited to, one or more single-walled, double-walled, and multi-walled carbon nanotubes. Specifically, it may contain single-walled carbon nanotubes. Since single-walled or double-walled carbon nanotubes have a higher specific surface area than multi-walled carbon nanotubes, they are more effective in improving cycle characteristics when applied to secondary batteries.

[0047] On the other hand, the average diameter of the carbon nanotubes may be, for example, 0.6 to 10 nm, preferably 0.8 to 5 nm, more preferably 0.8 to 3 nm, and may be 0.8 nm or more, 0.9 nm or more, 1.0 nm or more, 1.1 nm or more, 1.2 nm or more, 1.3 nm or more, 1.4 nm or more, 1.5 nm or more, 1.6 nm or more, 1.7 nm or more, 1.8 nm or more, or 1.9 nm or more, and may be 3.0 nm or less, 2.9 nm or less, 2.8 nm or less, 2.7 nm or less, 2.6 nm or less, 2.5 nm or less, 2.4 nm or less, 2.3 nm or less, 2.2 nm or less, 2.1 nm or less, or 2.0 nm or less.

[0048] Furthermore, the carbon nanotubes may have an average length of 0.5 to 20 μm, preferably 1 to 20 μm, more preferably 5 to 20 μm, and may also be 5 μm or more, 7 μm or more, 9 μm or more, 11 μm or more, or 13 μm or more, or 20 μm or less, 18 μm or less, 16 μm or less, or 14 μm or less. When the average diameter and average length of the carbon nanotubes satisfy the above range, it is effective in reducing the viscosity of the dispersion and improving storage stability, and excellent cycle characteristics can be achieved when the electrode active material is applied.

[0049] At this time, the average diameter of the carbon nanotubes can be measured by photographing the carbon nanotube powder with a scanning electron microscope, and the average length of the carbon nanotubes can be measured by photographing the carbon nanotube dispersion with a scanning electron microscope.

[0050] The carbon nanotubes may be contained in an amount of 0.05 to 5 parts by weight based on 100 parts by weight in total of the carbon nanotube dispersion liquid, and may be 0.05 parts by weight or more, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, 1.0 parts by weight or more, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, 1.5 parts by weight or more, 1.6 parts by weight or more, 1.7 parts by weight or more, 1.8 parts by weight or more, 1.9 parts by weight or more, 2.0 parts by weight or more, 2.1 parts by weight or more, 2.2 parts by weight or more, 2.3 parts by weight or more, 2.4 parts by weight or more or 2.5 parts by weight or more, and may be contained in an amount of 5 parts by weight or less, 4.9 parts by weight or less, 4.8 parts by weight or less, 4.7 parts by weight or less, 4.6 parts by weight or less, 4.5 parts by weight or less, 4.4 parts by weight or less, 4.3 parts by weight or less, 4.2 parts by weight or less, 4.1 parts by weight or less, 4 parts by weight or less, 3.9 parts by weight or less, 3.8 parts by weight or less, 3.7 parts by weight or less, 3.6 parts by weight or less, 3.5 parts by weight or less, 3.4 parts by weight or less, 3.3 parts by weight or less, 3.2 parts by weight or less, 3.1 parts by weight or less, 3 parts by weight or less, 2.9 parts by weight or less, 2.8 parts by weight or less, 2.7 parts by weight or less or 2.6 parts by weight or less. When the content of the carbon nanotubes satisfies the above range, the effect of improving the dispersion liquid viscosity and the effect of improving the conductivity of the secondary battery manufactured through the carbon nanotube dispersion liquid are excellent.

[0051] The BET specific surface area of the carbon nanotubes may be 800 m 2 / g to 2,000 m 2 / g, for example, 800 m 2 / g or more, 810 m 2 / g or more, 820 m 2 / g or more, 830 m 2 / g or more, 840 m[[ID=1​​​​​​​​​​​​​​​2 / g or more, 930m 2 / g or more, 940m 2 / g or more, 950m 2 / g or more, 960m 2 / g or more, 970m 2 / g or more, 980m 2 / g or more, 990m 2 / g or more, 1,000m 2 / g or more, 1,010m 2 / g or more, 1,020m 2 / g or more, 1,030m 2 / g or more, 1,040m 2 / g or more, 1,050m 2 / g or more, 1,060m 2 / g or more, 1,070m 2 / g or more, 1,080m 2 / g or more, 1,090m 2 / g or more, 1,100m 2 / g or more, 1,110m 2 / g or more, 1,120m 2 / g or more, 1,130m 2 / g or more, 1,140m 2 / g or more, 1,150m 2 / g or more, 1,160m 2 / g or more, 1,170m 2 / g or more, 1,180m 2 / g or more, 1,190m 2 / g or more, 1,200m 2 / g or more, 1,210m 2 / g or more, 1,220m 2 / g or more, 1,230m 2 / g or more, 1,240m 2 / g or more, 1,250m 2 / g or more, 1,260m 2 / g or more, 1,270m 2 / g or more, 1,280m 2 / g or more, 1,290m 2 / g or more, 1,300m 2 / g or more, 1,310m 2 / g or more, 1,320m 2 / g or more, 1,330m 2 / g or more, 1,340m2 above / g, 1,350 m 2 above / g, 1,360 m 2 above / g, 1,370 m 2 above / g, 1,380 m 2 above / g, 1,390 m 2 above / g or 1,400 m 2 it may be above / g and 2,000 m 2 below / g, 1,990 m 2 below / g, 1,980 m 2 below / g, 1,970 m 2 below / g, 1,960 m 2 below / g, 1,950 m 2 below / g, 1,940 m 2 below / g, 1,930 m 2 below / g, 1,920 m 2 below / g, 1,910 m 2 below / g, 1,900 m 2 below / g, 1,890 m 2 below / g, 1,880 m 2 below / g, 1,870 m 2 below / g, 1,860 m 2 below / g, 1,850 m 2 below / g, 1,840 m 2 below / g, 1,830 m 2 below / g, 1,820 m 2 below / g, 1,810 m 2 below / g, 1,800 m 2 below / g, 1,790 m 2 below / g, 1,780 m 2 below / g, 1,770 m 2 below / g, 1,760 m 2 below / g, 1,750 m 2 below / g, 1,740 m 2 below / g, 1,730 m 2 below / g, 1,720 m 2 below / g, 1,710 m 2 below / g, 1,700 m 2 below / g, 1,690 m 2 below / g, 1,680 m 2 below / g, 1,670 m 2 below / g, 1,660 m2 / g or less, 1,650m 2 / g or less, 1,640m 2 / g or less, 1,630m 2 / g or less, 1,620m 2 / g or less, 1,610m 2 / g or less, 1,600m 2 / g or less, 1,590m 2 / g or less, 1,580m 2 / g or less, 1,570m 2 / g or less, 1,560m 2 / g or less, 1,550m 2 / g or less, 1,540m 2 / g or less, 1,530m 2 / g or less, 1,520m 2 / g or less, 1,510m 2 / g or less, 1,500m 2 / g or less, 1,490m 2 / g or less, 1,480m 2 / g or less, 1,470m 2 / g or less, 1,460m 2 / g or less, 1,450m 2 / g or less, 1,440m 2 / g or less, 1,430m 2 / g or less, 1,420m 2 / g or less or 1,410m 2 It may be less than / g. As described above, using carbon nanotubes with a high BET specific surface area allows for excellent formation of conductive networks between electrode active materials, resulting in improved cycle characteristics of secondary batteries manufactured through the carbon nanotube dispersion.

[0052] A carbon nanotube dispersion according to one embodiment of the present invention can have a relatively high carbon nanotube content because the carbon nanotubes can be uniformly dispersed. When a carbon nanotube dispersion with a low carbon nanotube content is used in the manufacture of an electrode slurry, the solid content of the manufactured electrode slurry decreases, the thickness before coating and drying (wetting thickness) of the electrode slurry becomes thicker, and the rolling ratio measured after drying and rolling becomes higher, resulting in a large difference in the ratio of thickness before and after drying and rolling. When the rolling ratio is high in this way, the composition inside the slurry, including the positive electrode active material, may be damaged during the process, which can lead to problems such as a decrease in battery performance.

[0053] (2) Dispersant The carbon nanotube dispersion according to the present invention contains a dispersant to improve the dispersibility of the carbon nanotubes, and the dispersant comprises a first dispersant containing a nitrogen atom and a second dispersant containing a compound represented by the following chemical formula 1.

[0054] [ka]

[0055] In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and each is independently a substituted or unsubstituted C6-C30 aryl group. Ar2 to Ar5 are either identical or different from each other, and each is independently substituted or unsubstituted C6 to C30 arylene groups. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

[0056] In the carbon nanotube dispersion, the first and second dispersants increase the dispersibility of the carbon nanotubes so that they are uniformly dispersed without agglomerating in the dispersion. In particular, they suppress changes in the viscosity of the carbon nanotube dispersion over time and reduce the average particle size of the dispersed particles.

[0057] In a carbon nanotube dispersion according to one specific example of the present invention, the first dispersant containing nitrogen atoms may be soluble in an aqueous solvent as described later, and may be one or more selected from the group consisting of polyvinylpyrrolidone, polyacrylic acid hydrazide, poly-N-vinyl-5-methoxazolidon, N-alkyl polyimine, N-acetyl polyimine, polyacrylamide, poly-L-lysine hydrobromide, benzyl-dodecyl-dimethylammonium chloride, and polyethyleneimine, and preferably polyvinylpyrrolidone can be used. A carbon nanotube dispersion according to one specific example of the present invention can exhibit viscosity improvement and viscosity change suppression effects by containing the first dispersant containing nitrogen atoms.

[0058] In one specific example of the present invention, the first dispersant can be included in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of the carbon nanotube dispersion, for example, 0.01 parts by weight or more, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, 1 part by weight or more, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, 1.5 parts by weight or more, 1.6 parts by weight or more, 1.7 parts by weight or more, 1.8 parts by weight or more, 1.9 Part by weight or more, 2 parts by weight or more, 2.1 parts by weight or more, 2.2 parts by weight or more, 2.3 parts by weight or more, 2.4 parts by weight or more, 2.5 parts by weight or more, 2.6 parts by weight or more, 2.7 parts by weight or more, 2.8 parts by weight or more, 2.9 parts by weight or more, 3 parts by weight or more, 3.1 parts by weight or more, 3.2 parts by weight or more, 3.3 parts by weight or more 3.4 parts by weight or more, 3.5 parts by weight or more, 3.6 parts by weight or more, 3.7 parts by weight or more, 3.8 parts by weight or more, 3.9 parts by weight or more, 4 parts by weight or more, 4.1 parts by weight or more, 4.2 parts by weight or more, 4.3 parts by weight or more, 4.4 parts by weight or more, 4.5 parts by weight or more, 4.6 parts by weight or more, 4.7 parts by weight It can contain 10 parts or more, 4.8 parts by weight or more, 4.9 parts by weight or more, or 5 parts by weight or more, and 10 parts by weight or less, 9.9 parts by weight or less, 9.8 parts by weight or less, 9.7 parts by weight or less, 9.6 parts by weight or less, 9.5 parts by weight or less, 9.4 parts by weight or less, 9.3 parts by weight or less, 9.2 parts by weight or less, 9.1 parts by weight or less, 9 parts by weight or less, 8.9 parts by weight or less, 8.8 parts by weight or less, 8.7 parts by weight or less, 8.6 parts by weight or less, 8.5 parts by weight or less, 8.4 parts by weight or less, 8.3 parts by weight or less, 8.2 parts by weight or less, 8.1 parts by weight or less, 8 parts by weight or less, 7.9 parts by weight or less, 7.8 parts by weight or less, 7.7 It may contain parts by weight or less, 7.6 parts by weight or less, 7.5 parts by weight or less, 7.4 parts by weight or less, 7.3 parts by weight or less, 7.2 parts by weight or less, 7.1 parts by weight or less, 7 parts by weight or less, 6.9 parts by weight or less, 6.8 parts by weight or less, 6.7 parts by weight or less, 6.6 parts by weight or less, 6.5 parts by weight or less, 6.4 parts by weight or less, 6.3 parts by weight or less, 6.2 parts by weight or less, 6.1 parts by weight or less, 6 parts by weight or less, 5.9 parts by weight or less, 5.8 parts by weight or less, 5.7 parts by weight or less, 5.6 parts by weight or less, 5.5 parts by weight or less, 5.4 parts by weight or less, 5.3 parts by weight or less, 5.2 parts by weight or less, or 5.1 parts by weight or less.

[0059] If the content of the first dispersant is less than 0.01 parts by weight per 100 parts by weight of the carbon nanotube dispersion, the insufficient dispersant content may result in insufficient dispersion, leading to a low viscosity in the dispersion and potentially an increase in viscosity over time. Conversely, if the content exceeds 10 parts by weight, the excessive amount of the first dispersant may promote aggregation among the solid particles in the dispersion, resulting in a high viscosity.

[0060] Furthermore, in one embodiment of the present invention, in order to solve the problem in a carbon nanotube dispersion containing only the first dispersant, where the viscosity of the dispersion increases along with the carbon nanotube content, a second dispersant containing a compound represented by the following chemical formula 1 is included together with the first dispersant. As a result, compared to conventional carbon nanotube dispersions using only a dispersant, the dispersion exhibits superior dispersibility, less clumping of slurry composition particles, and a lower settling velocity.

[0061] [ka]

[0062] In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and each is independently a substituted or unsubstituted C6-C30 aryl group. Ar2 to Ar5 are either identical or different from each other, and each is independently substituted or unsubstituted C6 to C30 arylene groups. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

[0063] In one specific example of the present invention, Ar1 in chemical formula 1 may be a substituted or unsubstituted C6-C30 aryl group.

[0064] In one specific example of the present invention, Ar1 in chemical formula 1 may be a substituted or unsubstituted C6-C20 aryl group.

[0065] In one specific example of the present invention, Ar1 in chemical formula 1 may be a substituted or unsubstituted C6-C10 aryl group.

[0066] In one specific example of the present invention, Ar1 in chemical formula 1 may be a substituted or unsubstituted phenyl group.

[0067] In one specific example of the present invention, the Ar6 in chemical formula 1 may be a substituted or unsubstituted C6-C30 aryl group.

[0068] In one specific example of the present invention, the Ar6 in chemical formula 1 may be a substituted or unsubstituted C6-C20 aryl group.

[0069] In one specific example of the present invention, the Ar6 in chemical formula 1 may be a substituted or unsubstituted C6-C10 aryl group.

[0070] In one specific example of the present invention, Ar6 in chemical formula 1 may be a substituted or unsubstituted phenyl group.

[0071] In one specific example of the present invention, Ar2 in chemical formula 1 may be a substituted or unsubstituted C6-C30 arylene group.

[0072] In one specific example of the present invention, the Ar2 in chemical formula 1 may be a substituted or unsubstituted C6-C20 arylene group.

[0073] In one specific example of the present invention, the Ar2 in chemical formula 1 may be a substituted or unsubstituted C6-C10 arylene group.

[0074] In one specific example of the present invention, Ar2 in chemical formula 1 may be a substituted or unsubstituted phenylene group.

[0075] In one specific example of the present invention, the Ar3 in chemical formula 1 may be a substituted or unsubstituted C6-C30 arylene group.

[0076] In one specific example of the present invention, the Ar3 in chemical formula 1 may be a substituted or unsubstituted C6-C20 arylene group.

[0077] In one specific example of the present invention, the Ar3 in chemical formula 1 may be a substituted or unsubstituted C6-C10 arylene group.

[0078] In one specific example of the present invention, Ar3 in chemical formula 1 may be a substituted or unsubstituted phenylene group.

[0079] In one specific example of the present invention, the Ar4 in chemical formula 1 may be a substituted or unsubstituted C6-C30 arylene group.

[0080] In one specific example of the present invention, the Ar4 in chemical formula 1 may be a substituted or unsubstituted C6-C20 arylene group.

[0081] In one specific example of the present invention, the Ar4 in chemical formula 1 may be a substituted or unsubstituted C6-C10 arylene group.

[0082] In one specific example of the present invention, Ar4 in chemical formula 1 may be a substituted or unsubstituted phenylene group.

[0083] In one specific example of the present invention, Ar5 in chemical formula 1 may be a substituted or unsubstituted C6-C30 arylene group.

[0084] In one specific example of the present invention, Ar5 in chemical formula 1 may be a substituted or unsubstituted C6-C20 arylene group.

[0085] In one specific example of the present invention, Ar5 in chemical formula 1 may be a substituted or unsubstituted C6-C10 arylene group.

[0086] In one specific example of the present invention, Ar5 in chemical formula 1 may be a substituted or unsubstituted phenylene group.

[0087] In one specific example of the present invention, L1 in the chemical formula 1 may be a urea bond.

[0088] Furthermore, in one specific example of the present invention, Ar1 and Ar6 in Chemical Formula 1 may each be represented by the following Chemical Formula 2, Ar2 and Ar5 in Chemical Formula 1 may each be represented by the following Chemical Formula 3, and Ar3 and Ar4 in Chemical Formula 1 may each be represented by the following Chemical Formula 4.

[0089] [ka]

[0090] In the aforementioned chemical formula 2, R1 to R6 are either identical or different from each other, and each is independently a site that can be linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and one of R1 to R6 is a site that can be linked to an azo group of chemical formula 1. In the aforementioned chemical formula 3, R7 to R12 are either identical or different from each other, and each is independently a site that can be linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and at least two of R7 to R12 are sites that can be linked to azo group of chemical formula 1. In the aforementioned chemical formula 4, R13 to R20 are either identical or different to each other, and each is independently a hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; a site linked to the azo group of chemical formula 1; or a site linked to L1 of chemical formula 1, wherein at least one of R13 to R20 is a site linked to the azo group of chemical formula 1, and at least one of the other R13 to R20 (excluding the sites linked to the azo group of chemical formula 1) is a site linked to L1 of chemical formula 1.

[0091] In one specific example of the present invention, R1 to R6 of chemical formula 2 may be the same as or different from each other, and each may be independently a site that is linked to hydrogen, deuterium, a sulfonate group, a hydroxyl group, or an azo group of chemical formula 1, and any one of R1 to R6 may be a site that is linked to an azo group of chemical formula 1.

[0092] In one specific example of the present invention, R7 to R12 of chemical formula 3 may be the same as or different from each other, and each may be independently a site that is linked to hydrogen, deuterium, a sulfonate group, a hydroxyl group, or an azo group of chemical formula 1, and at least two of R7 to R12 may be sites that are linked to an azo group of chemical formula 1.

[0093] In one specific example of the present invention, R13 to R20 of chemical formula 4 may be the same as or different from each other, and each may independently be hydrogen; deuterium; a sulfonate group; a hydroxyl group; a site linked to the azo group of chemical formula 1; or a site linked to L1 of chemical formula 1, wherein at least one of R13 to R20 is a site linked to the azo group of chemical formula 1, and at least one of the other R13 to R20, excluding the site linked to the azo group of chemical formula 1, is a site linked to L1 of chemical formula 1.

[0094] In one specific example of the present invention, at least one of the R1 to R6 of Chemical Formula 2, excluding the part linked to the azo group of Chemical Formula 1, is a sulfonate group; at least one of the R7 to R12 of Chemical Formula 3, excluding the part linked to the azo group of Chemical Formula 1, is a sulfonate group; and at least one of the R13 to R20 of Chemical Formula 4, excluding the part linked to the azo group and L1 of Chemical Formula 1, is a sulfonate group.

[0095] In one specific example of the present invention, in the chemical formulas 2 to 4, if one or more of R1 to R20 are sulfonate groups, the anion of the sulfonate group may be in the form of a salt bonded to a metal cation, and more specifically, it may be a sodium salt of the sulfonate group.

[0096] In one specific example of the present invention, the second dispersant may contain a compound represented by the following chemical formula 1-1.

[0097] [ka]

[0098] In the above chemical formula 1-1, R1-R5, R7-R10, and R13-R18 are either identical or different from each other, and each is independently hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; or nitro group.

[0099] In one specific example of the present invention, R1 to R5 may be the same as or different from each other, and each may independently be hydrogen or a sulfonate group, and at least one of R1 to R5 may be a sulfonate group.

[0100] In one specific example of the present invention, R7 to R10 may be the same as or different from each other, and each may independently be a hydrogen or a sulfonate group, and at least one of R7 to R10 may be a sulfonate group.

[0101] In one specific example of the present invention, R13 to R18 may be the same as or different from each other, and each may independently be a hydrogen atom, a hydroxyl group, or a sulfonate group.

[0102] In one specific example of the present invention, the second dispersant may include a compound represented by the following chemical formula 5 (Direct Red 80).

[0103] [ka]

[0104] The compound represented by chemical formula 1 contained in the second dispersant contains mutually distinct aryl groups and arylene groups linked by azo groups. This allows for stable π-π interactions with carbon nanotubes in local regions, thereby ensuring sufficient bonding strength between the dispersant and carbon nanotubes, reducing the content of remaining dispersant that was not effectively adsorbed on the carbon nanotube surface, and preventing aggregation of residual dispersants.

[0105] Furthermore, in a carbon nanotube dispersion according to one specific example of the present invention, the compound represented by chemical formula 1 contained in the second dispersant contains a hydroxyl group, thereby forming a hydrogen bond with the solvent in the dispersion, enabling the "carbon nanotube-dispersant" conjugate to maintain a stable dispersed state in the solvent.

[0106] Furthermore, in a carbon nanotube dispersion according to one specific example of the present invention, the compound represented by chemical formula 1 contained in the second dispersant contains six or more sulfonate groups, which causes the dispersant to be ionized when dissolved in the solvent. This creates electrostatic repulsion between sulfonate anions, preventing aggregation between adjacent dispersants and allowing the "carbon nanotube-dispersant" conjugate to maintain a stable dispersed state in the solvent.

[0107] If the carbon nanotube dispersion does not contain the second dispersant according to the present invention, there is a risk that the area where the surface of the carbon nanotubes is not sufficiently covered by the dispersant will increase. As a result, a stronger bonding force than the appropriate degree may be generated between the carbon nanotubes, and as a result of aggregation between the carbon nanotubes, the viscosity of the dispersion may be increased.

[0108] In one specific example of the present invention, the second dispersant may be included in an amount of 0.001 to 9 parts by weight based on 100 parts by weight of the carbon nanotube dispersion, for example, 0.001 parts by weight or more, 0.01 parts by weight or more, 0.1 parts by weight or more, 0.2 parts by weight or more, 0.3 parts by weight or more, 0.4 parts by weight or more, 0.5 parts by weight or more, 0.6 parts by weight or more, 0.7 parts by weight or more, 0.8 parts by weight or more, 0.9 parts by weight or more, 1 part by weight or more, 1.1 parts by weight or more, 1.2 parts by weight or more, 1.3 parts by weight or more, 1.4 parts by weight or more, 1.5 parts by weight or more, 1.6 parts by weight or more, 1.7 parts by weight or more, 1.8 parts by weight or more, 1.9 parts by weight or more, 2 parts by weight or more, 2.1 parts by weight or more, 2.2 parts by weight or more, 2.3 parts by weight or more, 2.4 parts by weight or more, 2.5 parts by weight or more, 2.6 parts by weight or more, 2.7 parts by weight or more, 2.8 parts by weight or more Above, 2.9 parts by weight or more, 3 parts by weight or more, 3.1 parts by weight or more, 3.2 parts by weight or more, 3.3 parts by weight or more, 3.4 parts by weight or more, 3.5 parts by weight or more, 3.6 parts by weight or more, 3.7 parts by weight or more, 3.8 parts by weight or more, 3.9 parts by weight or more, 4 parts by weight or more, 4.1 parts by weight or more It can contain 4.2 parts by weight or more, 4.3 parts by weight or more, 4.4 parts by weight or more, or 4.5 parts by weight or more, and 9 parts by weight or less, 8.9 parts by weight or less, 8.8 parts by weight or less, 8.7 parts by weight or less, 8.6 parts by weight or less, 8.5 parts by weight or less, 8.4 parts by weight or less, 8.3 parts by weight or less, 8.2 parts by weight or less, 8.1 parts by weight or less, 8 parts by weight or less, 7.9 parts by weight or less, 7.8 parts by weight or less, 7.7 parts by weight or less, 7.6 parts by weight or less, 7.5 parts by weight or less, 7.4 parts by weight or less, 7.3 parts by weight or less, 7.2 parts by weight or less, 7.1 parts by weight or less, 7 parts by weight or less. It may contain up to 100 parts by weight, 6.9 parts by weight or less, 6.8 parts by weight or less, 6.7 parts by weight or less, 6.6 parts by weight or less, 6.5 parts by weight or less, 6.4 parts by weight or less, 6.3 parts by weight or less, 6.2 parts by weight or less, 6.1 parts by weight or less, 6 parts by weight or less, 5.9 parts by weight or less, 5.8 parts by weight or less, 5.7 parts by weight or less, 5.6 parts by weight or less, 5.5 parts by weight or less, 5.4 parts by weight or less, 5.3 parts by weight or less, 5.2 parts by weight or less, 5.1 parts by weight or less, 5 parts by weight or less, 4.9 parts by weight or less, 4.8 parts by weight or less, 4.7 parts by weight or less, or 4.6 parts by weight or less.

[0109] If the content of the second dispersant is less than 0.1 parts by weight per 100 parts by weight of the carbon nanotube dispersion, an effective dispersion effect may not be observed, resulting in a low viscosity dispersion that may not form, and a problem where the viscosity increases over time. If the content exceeds 10 parts by weight, the excessive content of the second dispersant may promote aggregation of solids in the dispersion, and problems may persist as long as the high viscosity of the dispersion is formed.

[0110] In one specific example of the present invention, the first dispersant and the second dispersant of the carbon nanotube dispersion may be included in a weight ratio of 100:10 to 100:90. For example, the ratio of the second dispersant to the first dispersant may be 100:10 or more, 100:15 or more, 100:17.65 or more, 100:20 or more, 100:25 or more, 100:30 or more, 100:33.33 or more, 100:35 or more, 100:40 or more, 100:45 or more, 100:50 or more, or 100:55 or more. The ratio of the second dispersant to the first dispersant may be 100:90 or less, 100:85 or less, 100:80 or less, 100:75 or less, 100:70 or less, 100:65 or less, or 100:60 or less.

[0111] When the first and second dispersants are contained in the carbon nanotube dispersion in the aforementioned weight ratio, the carbon nanotubes are uniformly dispersed in the carbon nanotube dispersion, and the viscosity can be maintained at a constant level over time, along with a low viscosity.

[0112] (3) Solvent The solvent in the carbon nanotube dispersion according to one embodiment of the present invention is used as a dispersion medium for dispersing the carbon nanotubes, the first dispersant, and the second dispersant. When powdered carbon nanotubes are used immediately in the production of an electrode slurry composition, the solvent is used to linearly disperse them and supply them to the carbon nanotube dispersion in order to prevent aggregation.

[0113] The solvent can dissolve or disperse the carbon nanotubes, the first dispersant, and the second dispersant to a certain level or higher. The aqueous solvent may be, for example, water, and may be included in a content such that the electrode slurry composition can have an appropriate viscosity, in view of the coating properties of the electrode slurry composition subsequently produced using the carbon nanotube dispersion.

[0114] In one embodiment of the present invention, the carbon nanotube dispersion allows the first and second dispersants to uniformly disperse the carbon nanotubes in the solvent, as described above, thereby reducing the average particle size distribution of dispersed particles contained in the dispersion, such as composites of carbon nanotubes and each dispersant.

[0115] The average particle size distribution (D) of the dispersed particles contained in the aforementioned dispersion. 50 The particle size may be, for example, 0.5 to 10 μm, 1 to 10 μm, 1 to 8 μm, preferably 1 to 5 μm.

[0116] The carbon nanotube dispersion of the present invention, containing the components described above, exhibits excellent dispersibility, low viscosity, and minimal viscosity increase over time.

[0117] The carbon nanotube dispersion may have an initial viscosity of 1 to 10 Pa·s, measured at 25°C and 1 rpm using a viscometer (TOKI SANGYO, viscometer TV-25, Rotor Code 01), for example, 1 Pa·s or more, 1.1 Pa·s or more, 1.2 Pa·s or more, 1.3 Pa·s or more, 1.4 Pa·s or more, 1.5 Pa·s or more, 1.6 Pa·s or more, 1.7 Pa·s or more, 1.8 Pa·s or more, 1.9 Pa·s or more, 2 Pa·s or more, 2.1 Pa·s or more, 2.2 Pa·s or more. Above, 2.3 Pa s or more, 2.4 Pa s or more, 2.5 Pa s or more, 2.6 Pa s or more, 2.7 Pa s or more, 2.8 Pa s or more, 2.9 Pa s or more, 3 Pa s or more, 3.1 Pa s or more, 3.2 Pa s or more, 3.3 Pa s or more, 3.4 Pa s or more, 3.5 Pa s or more, 3.6 Pa s or more, 3.7 Pa s or more, 3.8 Pa s or more, 3.9 Pa s or more, 4 Pa s or higher, 4.1 Pa·s or higher, 4.2 Pa·s or higher, 4.3 Pa·s or higher, 4.4 Pa·s, 4.5 Pa·s or higher, 4.6 Pa·s or higher, 4.7 Pa·s or higher, 4.8 Pa·s or higher, 4.9 Pa·s or higher, 5 Pa·s or higher, 5.1 Pa·s or higher, 5.2 Pa·s or higher, 5.3 Pa·s or higher, 5.4 Pa·s or higher, or 5.5 Pa·s or higher, and may be 10 Pa·s or lower, 9.9 Pa·s or higher. s or less, 9.8 Pa·s or less, 9.7 Pa·s or less, 9.6 Pa·s or less, 9.5 Pa·s or less, 9.4 Pa·s or less, 9.3 Pa·s or less, 9.2 Pa·s or less, 9.1 Pa·s or less, 9 Pa·s or less, 8.9 Pa·s or less, 8.8 Pa·s or less, 8.7 Pa·s or less, 8.6 Pa·s or less, 8.5 Pa·s or less, 8.4 Pa·s or less, 8.3 Pa·s or less, 8.2 Pa·s or less or 8.1 Pa s or less, 8 Pa s or less, 7.9 Pa s or less, 7.8 Pa s or less, 7.7 Pa s or less, 7.6 Pa s or less, 7.5 Pa s or less, 7.4 Pa s or less, 7.3 Pa s or less, 7.2 Pa s or less, 7.1 Pa s or less, 7 Pa s or less, 6. 9 Pa s or less, 6.8 Pa s or less, 6.7 Pa s or less, 6.6 Pa s or less, 6.5 Pa s or less, 6.4 Pa s or less, 6.3 Pa s or less, 6.2 Pa s or less, 6.1 Pa s or less, 6 Pa s or less, 5.9 Pa s or less, 5.8 Pa s or less, 5.The viscosity may be 7 Pa·s or less, or 5.6 Pa·s or less. If the carbon nanotube dispersion has an initial viscosity within this range, it can be used to more smoothly produce the electrode slurry, and the electrode slurry containing the carbon nanotube dispersion can have an appropriate viscosity for electrode formation.

[0118] Furthermore, when the carbon nanotube dispersion is left at 25°C for one week, the viscosity increase rate calculated by the following formula (1) may be 15% or less, specifically 15% or less, 14.5% or less, 14% or less, 13.5% or less, 13% or less, 12.5% ​​or less, 12.3% or less, 12% or less, 11.5% or less, 11% or less, 10.5% or less, 10% or less, 9.5% or less, 9% or less, 8.5% or less, 8% or less, 7.5% or less, 7% or less, 6.8% or less, 6.5% or less, 6.1% or less, 6% or less, 5.5% or less, 5% or less, 4.5% or less, 4% or less, 3.5% or less, 3% or less, 2.5% or less, 2.4% or less, 2% or less, 1.5% or less, or 1% or less.

[0119] [Formula 1] Viscosity increase rate (%) = {(Viscosity measured after being left at 25°C for one week - initial viscosity) / initial viscosity} × 100 At this time, the viscosity after being left for one week and the initial viscosity were measured at 25°C and 1 rpm.

[0120] Method for producing a carbon nanotube dispersion The following describes a method for producing a carbon nanotube dispersion according to one embodiment of the present invention.

[0121] The method for producing a carbon nanotube dispersion according to the present invention includes the steps of (1) mixing carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing a compound represented by the following chemical formula 1, and a solvent to produce a primary dispersion of carbon nanotubes; and (2) dispersing the primary dispersion of carbon nanotubes to produce a secondary dispersion of carbon nanotubes.

[0122] [ka]

[0123] In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and each is independently a substituted or unsubstituted C6-C30 aryl group. Ar2 to Ar5 are either identical or different from each other, and each is independently substituted or unsubstituted C6 to C30 arylene groups. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

[0124] In step (1), a primary dispersion of carbon nanotubes is prepared by mixing carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing the compound represented by chemical formula 1, and a solvent. The step of preparing the primary dispersion of carbon nanotubes is carried out in a wetting step in which each component is uniformly mixed.

[0125] The specific details of the carbon nanotubes, the first dispersant containing nitrogen atoms, the second dispersant containing the compound represented by chemical formula 1, and the solvent in the method for producing the carbon nanotube dispersion are as described above, and therefore, a detailed explanation will be omitted below.

[0126] The mixing for producing the primary dispersion of carbon nanotubes may be carried out using conventional mixing methods, specifically using mixing equipment such as a pony mixer, change-can mixer, Hobert mixer, pullenetri mixer, butterfly mixer, stone mill, homogenizer, bead mill, ball mill, basket mill, attrition mill, universal stirrer, clear mixer, or TK mixer, and may include a step of mixing at a rotational speed of 300 to 5,000 rpm for 30 minutes to 7 hours.

[0127] Furthermore, when mixing to produce the primary dispersion of carbon nanotubes, cavitation dispersion treatment may be performed to improve the miscibility between the carbon nanotubes and the solvent, or the dispersibility of the carbon nanotubes in the solvent. The cavitation dispersion treatment is a dispersion method that utilizes shock waves generated when vacuum bubbles formed in water burst when high energy is applied to the liquid, and this method can disperse carbon nanotubes without damaging their properties. Specifically, the cavitation dispersion treatment may be performed by ultrasound, jet milling, or shear dispersion treatment.

[0128] The production step of the primary dispersion of carbon nanotubes may be carried out under temperature conditions in which the physical properties of the mixture, such as viscosity, do not change due to the evaporation of the solvent. For example, it may be carried out at a temperature of 50°C or lower, or more specifically, between 5°C and 50°C.

[0129] In step (2), the primary dispersion of carbon nanotubes is dispersed to produce a secondary dispersion of carbon nanotubes.

[0130] The process for producing the secondary dispersion of carbon nanotubes may be carried out by methods such as a ball mill, bead mill, disc mill, or basket mill, or a high-pressure homogenizer, and more specifically, by a dispersion method using a high-pressure homogenizer.

[0131] Dispersion by the high-pressure disperser is carried out, for example, by pressing the mixture with the plunger pump of the high-pressure disperser and pushing it through the gap of the dispersion valve, through forces such as cavitation, shear, impact, and explosion as it passes through the gap.

[0132] The dispersion process may be performed according to the degree of dispersion of the carbon nanotube dispersion liquid. Specifically, it may be performed under a pressure of 5,000 to 30,000 psi for 30 to 120 minutes, more specifically 60 to 90 minutes, and the process can be repeated 1 to 10 times.

[0133] The carbon nanotube dispersion liquid according to the present invention may mean a secondary dispersion liquid of the carbon nanotubes.

[0134] Electrode slurry composition for lithium secondary battery In addition, the present invention provides an electrode slurry composition for a lithium secondary battery containing the carbon nanotube dispersion liquid and an electrode active material.

[0135] The electrode slurry composition for the lithium secondary battery may be a positive electrode slurry composition or a negative electrode slurry composition, and specifically, it may be a negative electrode slurry composition.

[0136] The electrode slurry composition for the lithium secondary battery may contain the carbon nanotube dispersion liquid, a positive electrode active material or a negative electrode active material as an electrode active material, a binder, and optionally a solvent and / or other additives.

[0137] As the positive electrode active material, well-known positive electrode active materials in the art may be used without limitation. For example, lithium cobalt-based oxides, lithium nickel-based oxides, lithium manganese-based oxides, lithium iron phosphate, lithium nickel manganese cobalt-based oxides, or combinations thereof may be used. Specifically, as the positive electrode active material, LiCoO2, LiNiO2, LiMn2O4, LiCoPO4, LiFePO4, and LiNiaMnbCocO2 (where 0 < a, b, c < 1) etc. may be used, but it is not limited thereto.

[0138] The negative electrode active material may be natural graphite, artificial graphite, carbonaceous material; lithium-containing titanium composite oxide (LTO), metals (Me) such as Si, Sn, Li, Zn, Mg, Cd, Ce, Ni, or Fe; alloys composed of the aforementioned metals (Me); or oxides (MeO) of the aforementioned metals (Me). x Examples of negative electrode active materials include one or more selected from the group consisting of ); and composites of the aforementioned metals (Me) and carbon. The negative electrode active material may be present in the negative electrode slurry at a concentration of 60 to 98% by weight, more preferably 70 to 98% by weight, based on the total weight of the solid matter excluding the solvent.

[0139] The aforementioned binder is a component that assists in the bonding of the active material to conductive materials and to the current collector, and is usually added at a concentration of 1 to 30% by weight based on the total weight of the mixture containing the electrode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene propylene dienterpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, fluororubber, and various copolymers.

[0140] The solvent may be an organic solvent such as N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, or dimethylacetamide, or water. These solvents can be used individually or in mixtures of two or more. The amount of solvent used should be sufficient to dissolve and disperse the electrode active material, binder, and conductive material, taking into consideration the thickness of the slurry coating and the production yield.

[0141] The viscosity modifier may be carboxymethylcellulose or polyacrylic acid, and by adding it, the viscosity of the electrode slurry can be adjusted to facilitate the manufacturing of the electrode slurry and the coating process on the electrode current collector.

[0142] The aforementioned filler is used selectively as a component to suppress electrode swelling, and is not particularly limited as long as it is a fibrous material that does not cause chemical changes in the battery. For example, olivine polymers such as polyethylene and polypropylene; and fibrous materials such as glass fibers and carbon fibers can be used.

[0143] If the electrode slurry composition is a composition for a positive electrode slurry to form a positive electrode, the positive electrode can be manufactured by applying the positive electrode slurry composition onto a positive electrode current collector, followed by drying and rolling. Alternatively, the positive electrode slurry can be cast separately onto a support, and the resulting film, obtained by peeling it off the support, can be laminated onto the positive electrode current collector.

[0144] The thickness of the positive electrode active material layer formed by the positive electrode slurry varies depending on the loading amount and loading speed for applying the positive electrode slurry.

[0145] The positive electrode current collector generally has a thickness of 3 μm to 500 μm. Such a positive electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes to the battery. For example, stainless steel, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel with a surface treatment of carbon, nickel, titanium, silver, etc. may be used. Furthermore, fine irregularities can be formed on the surface of the positive electrode current collector to strengthen the bonding force of the positive electrode active material, and it may be used in various forms such as film, sheet, foil, net, porous material, foam, nonwoven fabric.

[0146] If the electrode slurry composition is a negative electrode slurry composition for forming a negative electrode, the negative electrode can be manufactured by applying the negative electrode slurry composition onto a negative electrode current collector, followed by drying and rolling. Alternatively, the negative electrode slurry can be cast separately onto a support, and the resulting film, obtained by peeling it off the support, can be laminated onto the negative electrode current collector.

[0147] The thickness of the negative electrode active material layer formed by the negative electrode slurry varies depending on the loading amount and loading speed for applying the negative electrode slurry.

[0148] The negative electrode current collector generally has a thickness of 3 μm to 500 μm. Such a negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes to the battery, and may be made of materials such as copper, stainless steel, aluminum, nickel, titanium, calcined carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, etc., or aluminum-cadmium alloy. In addition, similar to the negative electrode current collector, fine irregularities can be formed on the surface to strengthen the bonding force of the negative electrode active material, and it may be used in various forms such as film, sheet, foil, net, porous material, foam, or nonwoven fabric.

[0149] Lithium-ion battery A lithium secondary battery includes a positive electrode, a negative electrode, a separator membrane placed between the positive and negative electrodes, and an electrolyte. Since the positive and negative electrodes are the same as described above, a detailed explanation is omitted.

[0150] The separation membrane separates the negative and positive electrodes and provides a pathway for lithium ions to move. It can be used without particular limitations as long as it is a membrane typically used in lithium secondary batteries. Particularly preferred is one that exhibits low resistance to ion movement of the electrolyte and has excellent moisture-retaining capacity for the electrolyte. Specifically, porous polymer films, such as polyolefin polymers like ethylene homopolymer, propylene homopolymer, ethylene / butene copolymer, ethylene / hexene copolymer, and ethylene / methacrylate copolymer, or laminated structures of two or more layers thereof, may be used. Alternatively, ordinary porous nonwoven fabrics, such as nonwoven fabrics made of high-melting-point glass fibers or polyethylene terephthalate fibers, may be used. Furthermore, to ensure heat resistance or mechanical strength, coated separation membranes containing ceramic components or polymeric substances may be used, and they may be selectively used in single-layer or multi-layer structures.

[0151] The electrolyte may be, but is not limited to, an organic liquid electrolyte, an inorganic liquid electrolyte, a solid polymer electrolyte, a gel polymer electrolyte, a solid inorganic electrolyte, or a molten inorganic electrolyte that can be used in the manufacture of lithium secondary batteries. Specifically, the electrolyte may contain an organic solvent and a lithium salt.

[0152] The organic solvent can be any solvent that can act as a medium through which ions involved in the electrochemical reaction of the battery can move, without any particular limitations. Specifically, the organic solvents include ester solvents such as methyl acetate, ethyl acetate, γ-butyrolactone, and ε-caprolactone; ether solvents such as dibutyl ether or tetrahydrofuran; ketone solvents such as cyclohexanone; aromatic hydrocarbon solvents such as benzene and fluorobenzene; dimethyl carbonate (DMC), diethyl carbonate (DEC), methyl ethyl carbonate (MEC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), and propylene carbonate (propylene Carbonate solvents such as carbonate (PC); alcoholic solvents such as ethanol and isopropyl alcohol; nitriles such as R-CN (where R is a linear, branched, or cyclic hydrocarbon group of C2-C20, and may include a double-bonded aromatic ring or ether bond); amides such as dimethylformamide; dioxolanes such as 1,3-dioxolane; or sulfolanes may be used. Among these, carbonate solvents are preferred, and a mixture of a cyclic carbonate (e.g., ethylene carbonate or propylene carbonate) having high ionic conductivity and high dielectric constant that can improve the charge and discharge performance of the battery, and a low-viscosity linear carbonate compound (e.g., ethyl methyl carbonate, dimethyl carbonate, or diethyl carbonate) is more preferred. In this case, the electrolyte performance is best demonstrated when the cyclic carbonate and the linear carbonate are mixed in a volume ratio of about 1:1 to about 1:9.

[0153] The lithium salt may be any compound capable of providing lithium ions for use in lithium secondary batteries, without any particular limitations. Specifically, the lithium salt may be LiPF6, LiClO4, LiAsF6, LiBF4, LiSbF6, LiAlO4, LiAlCl4, LiCF3SO3, LiC4F9SO3, LiN(C2F5SO3)2, LiN(C2F5SO2)2, LiN(CF3SO2)2, LiCl, LiI, or LiB(C2O4)2, etc. The concentration of the lithium salt should preferably be within the range of 0.1M to 2.0M. If the concentration of the lithium salt falls within this range, the electrolyte will have appropriate conductivity and viscosity, exhibiting excellent electrolyte performance and allowing lithium ions to move effectively.

[0154] In addition to the components of the electrolyte, the electrolyte may further contain one or more additives for the purpose of improving battery life characteristics, suppressing the decrease in battery capacity, and improving battery discharge capacity, such as haloalkylene carbonate compounds like difluoroethylene carbonate, pyridine, triethyl phosphite, triethanolamine, cyclic ethers, ethylenediamine, n-glyme, hexaphosphate triamide, nitrobenzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinone, N,N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salts, pyrrole, 2-methoxyethanol, or aluminum trichloride. In this case, the additive may be present in an amount of 0.1% to 5% by weight relative to the total weight of the electrolyte.

[0155] A lithium secondary battery containing an electrode manufactured using the carbon nanotube dispersion according to the present invention, specifically a lithium secondary battery containing a negative electrode manufactured using the carbon nanotube dispersion, has carbon nanotubes uniformly dispersed within the negative electrode. Compared to conventional batteries containing conductive materials such as carbon black, the content of such materials can be reduced, and it can stably exhibit superior discharge capacity and output characteristics. As a result, it can be usefully used in portable devices such as mobile phones, laptop computers, and digital cameras, as well as in electric vehicles such as hybrid electric vehicles (HEVs).

[0156] Accordingly, according to another embodiment of the present invention, a lithium secondary battery, a battery module containing the lithium secondary battery as a unit cell, and a battery pack containing the same are provided.

[0157] The battery module or battery pack may be used as a power source for one or more medium-to-large devices in a power tool; an electric vehicle (EV), a hybrid electric vehicle, or a plug-in hybrid electric vehicle (PHEV); or a power storage system. [Modes for carrying out the invention]

[0158] The following describes specific embodiments of the present invention. However, these embodiments are merely for illustrative purposes and to explain the present invention, and do not limit it. Furthermore, any matters not described herein can be sufficiently inferred by technical analogy by those skilled in the art, and therefore their explanations are omitted.

[0159] Examples Example 1 (1) 4.5 g of polyvinylpyrrolidone (PVP) (PVP K15, manufactured by Zhangzhou Huafu Chemical) as a first dispersant containing nitrogen atoms (0.9 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion), 1.5 g of Direct Red 80 (manufactured by Sigma Aldrich) as a second dispersant containing a compound represented by chemical formula 1 (0.3 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion), and 490 g of water as a solvent are mixed to produce 496 g of a mixed solution. This is then placed in a dissolver (Dispermat-CA, manufactured by VMA-GETZMANN) equipped with an impeller and container, and mixed by stirring at 400 rpm for 10 minutes.

[0160] The above mixture has a specific surface area of ​​1,160 m². 2 / g, average particle size (D 50 4.0 g of 5 μm single-walled carbon nanotubes (SWCNT, TUBALL, manufactured by OCSiAl) (0.8 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) are added, and the mixture is stirred at 8,000 rpm for 60 minutes to produce a total of 500 g of primary dispersion of carbon nanotubes.

[0161] (3) The primary dispersion of carbon nanotubes was homogeneously dispersed seven times at a pressure of 14,000 psi using a high-pressure disperser (PICOMAX, manufactured by Micronox) to produce a secondary dispersion of carbon nanotubes.

[0162] Example 2 A carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the first dispersant was set to 4.8 g (0.96 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the content of the second dispersant was set to 1.2 g (0.24 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion).

[0163] Example 3 A carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the first dispersant was set to 4.0 g (0.8 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the content of the second dispersant was set to 2.0 g (0.4 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion).

[0164] Comparative Example 1 In Example 1, the carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the first dispersant was 6.0 g (1.2 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the second dispersant was not added.

[0165] Comparative Example 2 A carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the first dispersant was set to 3.0 g (0.6 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the content of the second dispersant was set to 3.0 g (0.6 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion).

[0166] Comparative Example 3 A carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the first dispersant was set to 5.6 g (1.12 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the content of the second dispersant was set to 0.4 g (0.08 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion).

[0167] Comparative Example 4 In the above-mentioned Example 1, a carbon nanotube dispersion was prepared in the same manner as in Example 1, except that the content of the second dispersant was added to 6.0 g (1.2 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) and the first dispersant was not added.

[0168] Comparative Example 5 In Example 3, a carbon nanotube dispersion was prepared in the same manner as in Example 3, except that the content of the first dispersant was changed to 3.375 g (0.6 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion), and the second dispersant was changed to 1.125 g of tristyrylphenol ethoxylate (0.225 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) instead of Direct Red 80 (manufactured by Sigma Aldrich).

[0169] Comparative Example 6 A carbon nanotube dispersion was prepared in the same manner as in Example 3, except that the content of the first dispersant was changed to 3.375 g (0.6 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion), and the second dispersant was changed to 1.125 g of styrene maleic acid copolymer (0.225 parts by weight relative to 100 parts by weight of the total carbon nanotube dispersion) instead of Direct Red 80 (manufactured by Sigma Aldrich).

[0170] Experimental example The viscosity of the carbon nanotube dispersions of Examples 1-3 and Comparative Examples 1-6 was measured, and the viscosity was measured again after leaving them at 25°C for one week. The results are shown in Table 1 below.

[0171] Viscosity was measured at 25°C and 1 rpm using a viscometer (TOKI SANGYO, viscometer TV-25, Rotor Code 01).

[0172] [Table 1]

[0173] (*The content of CNTs, the first dispersant, and the second dispersant is based on 100 parts by weight of the total carbon nanotube dispersion.) (*"Ratio" refers to the weight ratio of the second dispersant to the first dispersant.) Referring to Table 1 above, it can be confirmed that, compared to the carbon nanotube dispersion of Comparative Example 1, which contains only polyvinylpyrrolidone as the first dispersant, the carbon nanotube dispersions of Examples 1 to 3, which contain both the first dispersant and Direct Red 80, a compound represented by chemical formula 1 of the present invention, as the second dispersant, have a lower initial viscosity immediately after the carbon nanotubes are dispersed in an aqueous solvent. In particular, it can be confirmed that the increase in viscosity of the carbon nanotube dispersion over time is very effectively suppressed.

[0174] In the case of the carbon nanotube dispersions of Comparative Examples 2 and 3, it can be seen that the initial viscosity immediately after dispersing the carbon nanotubes in the aqueous solvent is high, and the effect of suppressing the increase in viscosity of the dispersion over time is not exhibited, either because the second dispersant is present in an excessive amount (Comparative Example 2) or below a certain amount (Comparative Example 3) compared to the carbon nanotube dispersions of Examples 1 to 3.

[0175] In the case of the carbon nanotube dispersion of Comparative Example 4, it can be confirmed that the absence of the first dispersant compared to the carbon nanotube dispersions of Examples 1 to 3 results in a problem where the viscosity of the carbon nanotube dispersion increases rapidly over time.

[0176] In the case of the carbon nanotube dispersions of Comparative Examples 5 and 6, it can be seen that, compared to the carbon nanotube dispersions of Examples 1 to 3, the initial viscosity immediately after dispersing the carbon nanotubes in the aqueous solvent is high because the compound represented by chemical formula 1 according to the present invention is not used as the second dispersant, and the effect of suppressing the increase in viscosity of the carbon nanotube dispersion over time is not observed.

[0177] Therefore, it was confirmed that a carbon nanotube dispersion, obtained by dispersing carbon nanotubes in an aqueous solvent, contains a first dispersant containing nitrogen atoms and a second dispersant containing a compound represented by chemical formula 1 according to the present invention, and that the carbon nanotube dispersion exhibits low viscosity and the increase in viscosity over time is suppressed only when the first and second dispersants are present in a certain weight ratio.

[0178] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art that utilize the basic concepts of the present invention as defined in the following claims also fall within the scope of the present invention.

Claims

1. Carbon nanotubes; A first dispersant containing nitrogen atoms; A second dispersant containing the compound represented by the following chemical formula 1; and containing a solvent Carbon nanotube dispersion: 【Chemistry 1】 In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and are independently substituted or unsubstituted C6-C30 aryl groups. Ar2 to Ar5 are either identical or different, and each is independently a substituted or unsubstituted C6 to C30 arylene group. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

2. Ar1 and Ar6 in the aforementioned chemical formula 1 are represented by the following chemical formula 2, Ar2 and Ar5 in the aforementioned chemical formula 1 are represented by the following chemical formula 3, Ar3 and Ar4 in the aforementioned chemical formula 1 are represented by the following chemical formula 4, Carbon nanotube dispersion according to claim 1: 【Chemistry 2】 In the aforementioned chemical formula 2, R1 to R6 are either identical or different from each other, and each is independently a site that is linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and at least one of R1 to R6 is a site that is linked to an azo group of chemical formula 1. In the aforementioned chemical formula 3, R7 to R12 are either identical or different from each other, and each is independently a site that is linked to hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; or azo group of chemical formula 1, and at least two of R7 to R12 are sites that are linked to azo group of chemical formula 1. In the aforementioned chemical formula 4, R13 to R20 are either identical or different to each other, and each is independently a hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; nitro group; a site that connects to the azo group of chemical formula 1; or a site that connects to L1 of chemical formula 1, wherein at least one of R13 to R20 is a site that connects to the azo group of chemical formula 1, and at least one of the other R13 to R20 (excluding the sites that connect to the azo group of chemical formula 1) is a site that connects to L1 of chemical formula 1.

3. Among the R1 to R6 of the aforementioned chemical formula 2, excluding the part linked to the azo group of chemical formula 1, at least one of them is a sulfonate group. Among the R7 to R12 of the aforementioned chemical formula 3, excluding the part linked to the azo group of chemical formula 1, at least one of them is a sulfonate group. Among the R13 to R20 of the aforementioned chemical formula 4, excluding the azo group and the part linked to L1 of chemical formula 1, at least one of them is a sulfonate group. The carbon nanotube dispersion according to claim 2.

4. The second dispersant contains a compound represented by the following chemical formula 1-1, Carbon nanotube dispersion according to claim 1: 【Transformation 3】 In the above chemical formula 1-1, R1-R5, R7-R10, and R13-R18 are either identical or different from each other, and each is independently hydrogen; deuterium; halogen; cyano group; sulfonate group; hydroxyl group; amine group; or nitro group.

5. The carbon nanotube dispersion contains 0.05 to 5 parts by weight of carbon nanotubes based on 100 parts by weight of the carbon nanotube dispersion. The carbon nanotube dispersion according to claim 1.

6. The BET specific surface area of ​​the carbon nanotube is 800 to 2,000 m². ２ / g is The carbon nanotube dispersion according to claim 1.

7. The first dispersant is polyvinylpyrrolidone, polyacrylate hydrazide, poly-N-vinyl-5-methoxazolidon, N-alkyl polyimine, N-acetyl polyimine, polyacrylamide, poly-L-lysine hydrobromide, benzyl-dodecyl-dimethylammonium chloride It is one or more selected from the group consisting of chloride and polyethyleneimine. The carbon nanotube dispersion according to claim 1.

8. The first dispersant is contained in an amount of 0.01 to 10 parts by weight, based on 100 parts by weight of the carbon nanotube dispersion. The carbon nanotube dispersion according to claim 1.

9. The second dispersant is contained in an amount of 0.001 to 9 parts by weight, based on 100 parts by weight of the carbon nanotube dispersion. The carbon nanotube dispersion according to claim 1.

10. The first and second dispersants are present in a weight ratio of 100:10 to 100:

90. The carbon nanotube dispersion according to claim 1.

11. The carbon nanotube dispersion has an initial viscosity of 1 to 10 Pa·s, measured at 25°C and 1 rpm. The carbon nanotube dispersion according to claim 1.

12. The carbon nanotube dispersion has a viscosity increase rate of 15% or less, as represented by the following formula (1). Carbon nanotube dispersion according to claim 1: [Formula 1] Viscosity increase rate (%) = {(Viscosity measured after being left at 25°C for one week - initial viscosity) / initial viscosity} × 100.

13. (1) A step of preparing a primary dispersion of carbon nanotubes by mixing carbon nanotubes, a first dispersant containing nitrogen atoms, a second dispersant containing a compound represented by the following chemical formula 1, and a solvent; and (2) A step of producing a secondary dispersion of carbon nanotubes by dispersing the primary dispersion of carbon nanotubes; A method for producing a carbon nanotube dispersion according to claim 1, comprising: 【Chemistry 4】 In the aforementioned chemical formula 1, Ar1 and Ar6 are either identical or different, and are independently substituted or unsubstituted C6-C30 aryl groups. Ar2 to Ar5 are either identical or different, and each is independently a substituted or unsubstituted C6 to C30 arylene group. L1 is an amino, ether, thio, hydrazine, sulfinate, sulfonate, sulfonamide, ester, carbonate, carbamate, amide, or urea bond.

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