CN-121493953-B - Preparation method of single-walled carbon nanotube slurry, single-walled carbon nanotube slurry and application thereof

CN121493953BCN 121493953 BCN121493953 BCN 121493953BCN-121493953-B

Abstract

The application relates to the technical field of nano carbon materials, and particularly discloses a preparation method of single-walled carbon nanotube slurry, the single-walled carbon nanotube slurry and application thereof, wherein the preparation method of the single-walled carbon nanotube slurry comprises the following steps of carrying out low-temperature plasma oxidation treatment on single-walled carbon nanotubes with the diameters of the tube bundles of less than or equal to 100nm and the I G /I D of more than or equal to 50, and simultaneously carrying out mechanical shearing and dispersing the single-walled carbon nanotubes in deionized water to obtain primary dispersion liquid with the beam splitting index of more than or equal to 0.80; mixing the primary dispersion liquid, the fluorine-containing surfactant, the amphiphilic ionic liquid and deionized water according to the mass ratio, carrying out ultrasonic treatment after high-pressure homogenization to obtain a secondary dispersion liquid, adding a pH response polyelectrolyte into the secondary dispersion liquid, regulating the pH of a system to 6.5-8.0, and carrying out micro-jet homogenization to obtain single-wall carbon nanotube slurry with single-beam content of more than or equal to 70%, viscosity of 500-5000cP and D50 of less than or equal to 3 mu m. The application can realize high efficiency Jie Shu, long-term stable dispersion and batch consistency of the single-wall carbon nano tube on the premise of not introducing metal impurities and obvious structural defects.

Inventors

LI JIAYI
BI CHONGQIANG

Assignees

上海沪正实业有限公司

Dates

Publication Date: 20260512
Application Date: 20251021

Claims (4)

1. The preparation method of the single-walled carbon nanotube slurry is characterized by comprising the following steps of: S1, treating single-wall carbon nano tubes with tube bundle diameter less than or equal to 100nm and I G /I D more than or equal to 50 in low-temperature plasma atmosphere with oxygen volume fraction of 5-15% for 30-300S at 20-100W power, simultaneously applying mechanical shearing at 5000-15000rpm, and dispersing the single-wall carbon nano tubes/small-wall carbon nano tubes after beam splitting in deionized water to obtain primary dispersion liquid; S2, mixing the primary dispersion liquid, the fluorine-containing surfactant, the amphiphilic ionic liquid and deionized water according to the mass ratio of (5.5-55): (0.1-2): (0.05-0.5): (42.5-94.35), homogenizing for 1-5 times under the high pressure of 50-150MPa, and then carrying out ultrasonic treatment for 2-10min under the conditions of 20-40kHz and the power density of 50-200 W.L -1 to obtain a secondary dispersion liquid; S3, adding pH response polyelectrolyte into the secondary dispersion liquid, regulating the pH of the system to 6.5-8.0, and treating for 1-3 times by a micro-jet homogenizer at 80-150MPa to obtain single-wall carbon nanotube slurry with single-beam content of more than or equal to 70%, viscosity of 500-5000cP and D50 of less than or equal to 3 mu m; wherein the fluorine-containing surfactant is sodium perfluorooctyl sulfonate, lithium perfluorodecanoate or a mixture of the sodium perfluorooctyl sulfonate and the lithium perfluorodecanoate, and the HLB value of the fluorine-containing surfactant is 8-12; The amphiphilic ionic liquid is 1-butyl-3-methylimidazole tetrafluoroborate, 1-dodecyl-3-methylimidazole bromide or a mixture of the two; The pH-responsive polyelectrolyte is a polyacrylic acid-polyethylene glycol block copolymer or a poly (2-vinyl pyridine) -b-polyethylene oxide block copolymer, the number average molecular weight of the pH-responsive polyelectrolyte is 5-30kg & mol -1 , and the mass percentage of the pH-responsive polyelectrolyte in the slurry is 0.02-0.05%.
2. A single-wall carbon nanotube slurry prepared by the method for preparing the single-wall carbon nanotube slurry according to claim 1.
3. The single-walled carbon nanotube slurry of claim 2 wherein the single-walled carbon nanotubes have an absolute value of Zeta greater than or equal to 40 mV and a conductivity greater than or equal to 1000S m -1 .
4. Use of the single-walled carbon nanotube slurry of any of claims 2-3 in a positive or negative electrode current conducting agent, a flexible transparent conductive film or a thermally conductive interface material for a lithium ion battery.

Description

Preparation method of single-walled carbon nanotube slurry, single-walled carbon nanotube slurry and application thereof Technical Field The application relates to the technical field of nano carbon materials, in particular to a preparation method of single-walled carbon nanotube slurry, the single-walled carbon nanotube slurry and application thereof. Background The single-wall carbon nano tube has excellent electrical, mechanical and thermal properties, and is an ideal candidate for the next generation of conductive additives. However, there are strong van der Waals forces and pi-pi interactions between single-walled carbon nanotube molecules, which are very likely to form bundles of hundreds of nanometers in diameter, resulting in difficulty in dispersion in solvents, severely limiting the efficiency of the construction of their conductive networks. At present, high-energy ultrasonic, ball milling or a large amount of surfactant and other methods are mainly adopted to perform object understanding beam on the single-wall carbon nano tube, but the high-energy mechanical action is easy to introduce irreversible defects into the crystal lattice of the single-wall carbon nano tube, so that the I G/ID value is reduced, and the conductivity of the single-wall carbon nano tube is damaged. Excess surfactant may remain in the final electrode, increasing interfacial resistance. In addition, conventional shear flow fields are difficult to achieve industrial scale continuous processing. Therefore, there is a need to develop a single-walled carbon nanotube slurry that combines efficient beam splitting, low defects, low residue, and large-scale feasibility to solve the above-mentioned technical bottlenecks. Disclosure of Invention In order to obtain the single-walled carbon nanotube slurry with high-efficiency beam splitting, low defects, low residues and large-scale feasibility, the application provides a preparation method of the single-walled carbon nanotube slurry, the single-walled carbon nanotube slurry and application thereof, and the preparation method is based on a low-temperature plasma oxidation-mechanical shearing synergistic mechanism, and realizes high-efficiency Jie Shu, long-term stable dispersion and batch consistency of the single-walled carbon nanotubes on the premise of not introducing metal impurities and obvious structural defects. In a first aspect, the present application provides a method for preparing a single-walled carbon nanotube slurry, which adopts the following technical scheme: A method for preparing single-walled carbon nanotube slurry, comprising the steps of: S1, carrying out low-temperature plasma oxidation treatment on single-wall carbon nanotubes with the diameters of less than or equal to 100nm and I G/ID to more than or equal to 50, and simultaneously carrying out mechanical shearing, wherein single-wall carbon nanotubes/small-wall carbon nanotubes after beam splitting are dispersed in deionized water with ten times the mass of the single-wall carbon nanotubes, so as to obtain primary dispersion liquid with the beam splitting index of more than or equal to 0.80; S2, mixing the primary dispersion liquid, the fluorine-containing surfactant, the amphiphilic ionic liquid and deionized water according to the mass ratio of (5.5-55): 0.1-2): 0.05-0.5): 42.5-94.35, homogenizing under high pressure, and performing ultrasonic treatment to obtain a secondary dispersion liquid; s3, adding pH response polyelectrolyte into the secondary dispersion liquid, regulating the pH of the system to 6.5-8.0, and homogenizing by microjet to obtain single-wall carbon nanotube slurry with single-wall content more than or equal to 70%, viscosity of 500-5000cP and D50 less than or equal to 3 mu m, wherein the mass percentage of the pH response polyelectrolyte in the single-wall carbon nanotube slurry is 0.02-0.05%; Wherein, the single-beam/small-beam carbon nano tube refers to single-wall carbon nano tube with the diameter less than or equal to 100nm, the beam splitting index refers to the proportion of the single-beam carbon nano tube and the small-beam carbon nano tube in the primary dispersion liquid, namely, the beam splitting index is more than or equal to 0.80, which means that at least 80 percent of the single-wall carbon nano tube in the primary dispersion liquid exists in the form of single beam or small beam. Specifically, the beamsplitting index is obtained by the following measurement method: the tube bundle diameter distribution was observed by Transmission Electron Microscopy (TEM), and the ratio of single beam/small beam after beam splitting was counted. By adopting the technical scheme, oxygen-containing functional groups are introduced into the surface of the single-walled carbon nanotube by low-temperature plasma to generate local coulomb repulsion, so that the Van der Waals force between tube bundles is obviously weakened, and meanwhile, lattice damage caused by high-temperature oxidation