A method for efficiently preparing a single-walled carbon nanotube paste

Abstract

The present application belongs to the technical field of conductive carbon paste, and discloses a method for efficiently preparing single-walled carbon nanotube paste, which comprises the following steps: step one, mixing single-walled carbon nanotube powder with a dispersing agent and a solvent, and dispersing the mixture into uniform carbon nanotube bundle slurry through mechanical stirring, emulsification and other modes; step two, making the uniform carbon nanotube bundle slurry pass through different micropore channels for multiple times under a high-pressure environment, so that the carbon nanotube bundle slurry is dispersed into uniform single-walled carbon nanotube slurry. Through the special high-pressure homogenization channel, the single-walled carbon nanotube bundles adhered and wound together can be dispersed into single-walled carbon nanotube slurry under the premise of guaranteeing the length of the single-walled carbon nanotube as much as possible. The uniform dispersion, the long diameter of the single-walled carbon nanotube, and the single-walled carbon nanotube in a micro-quantity guarantee the excellent conductive performance of the slurry.

Description

Technical Field

[0001] This invention belongs to the field of conductive carbon paste technology and discloses a method for efficiently preparing single-walled carbon nanotube paste. Background Technology

[0002] Existing single-walled carbon nanotube (SWCNT) slurry preparation and dispersion technologies can be mainly divided into physical methods, chemical methods, combined physical and chemical methods, and novel spontaneous dispersion technologies.

[0003] Physical dispersion uses mechanical forces (such as shearing, grinding, and ultrasound) to break up the agglomeration of carbon nanotubes, thus achieving dispersion. This method eliminates the need for chemical additives, reducing their impact on conductivity, and the equipment is currently mature and suitable for large-scale production. However, mechanical forces can damage the carbon nanotube structure, leading to defects, and the dispersion effect is highly dependent on the equipment, making optimization difficult. Typical methods include three-roll milling, high-pressure homogenization, and ultrasonic treatment. Three-roll milling achieves dispersion through the shearing force of the rollers, generally achieving uniform dispersion without damaging the carbon nanotube structure, but its efficiency is very low. High-pressure homogenization utilizes the cavitation, impact, and shearing effects of a high-pressure homogenizer to achieve homogenization, pulverization, and emulsification of liquid samples. However, simple high-pressure homogenization for dispersing single-walled carbon nanotubes suffers from low efficiency, high energy consumption, and high required pressures, typically exceeding 2000 bar and requiring 10 or more homogenization passes, placing a heavy burden on the equipment. Ultrasonic treatment uses high-frequency vibration to deagglomerate, but the time must be controlled to avoid significant damage to the carbon nanotubes.

[0004] Chemical dispersion improves the solubility of carbon nanotubes through chemical modification or surfactants to achieve dispersion. This method offers high stability, wide applicability, and suitability for both aqueous and organic solvent systems. It is mainly divided into covalent functionalization and non-covalent functionalization. Covalent functionalization utilizes strong acids (such as nitric acid and sulfuric acid) to oxidize the surface, introducing functional groups (such as -COOH) to enhance dispersibility. Non-covalent functionalization uses surfactants (such as Pluronic F108) or polymers to encapsulate the carbon nanotubes, stabilizing dispersion through intermolecular forces. However, covalent modification disrupts the sp² structure of carbon nanotubes, reducing conductivity and mechanical properties, while non-covalent modification requires the addition of large amounts of surfactants, affecting the overall material properties and limiting applications.

[0005] Besides simple physical and chemical dispersion methods, there are also spontaneous dispersion and green dispersion technologies. Spontaneous dispersion utilizes the selective functionalization of carbon nanotube byproducts to achieve spontaneous dispersion. For example, the superacid intercalation method uses fuming sulfuric acid to intercalate carbon nanotube bundles, improving solvent affinity through functionalized byproducts, allowing dispersion without external force. This method involves strong acid treatment, posing a high risk of environmental pollution and requiring stringent process conditions, with high precision in controlling reaction temperature and time. Green dispersion technologies are based on environmental protection and biocompatibility, such as Pluronic F108, which achieves biocompatible dispersion through non-covalent modification; and OCSiAl's TUBALL™ series, which requires low dispersant dosage and is suitable for environmentally friendly coatings. This dispersion technology relies on newly developed dispersants, affecting material purity, limiting the application of the dispersion, and the dispersion process is not yet mature enough for industrial production.

[0006] Currently, the most widely used dispersion method is the physicochemical combination method, which combines mechanical force with chemical treatment. This process has high dispersion efficiency, and the combination of physicochemical methods can reduce the amount of chemical reagents used, improve the material purity of the finished slurry, and the production process is relatively environmentally friendly. However, this process requires multiple steps (such as wetting, polymerization, grinding, etc.), and the dispersion equipment is used in conjunction with dispersants, making the process relatively complex. Moreover, single-walled carbon nanotubes are difficult to disperse completely, and the finished slurry usually contains many broken or damaged single-walled carbon nanotubes, affecting the final conductivity of the slurry. Typical processes include ultrasonic dispersion with surfactants, i.e., ultrasonic dispersion followed by surfactant stabilization; and in-situ polymerization with high-pressure homogenization, i.e., wetting carbon nanotubes with polymerizable monomers, combined with grinding and homogenization to achieve multi-stage dispersion.

[0007] Due to their extremely high aspect ratio and strong van der Waals forces, single-walled carbon nanotubes (SUVs) are prone to aggregation and entanglement, forming difficult-to-disperse bundles. This aggregation severely hinders the realization of the inherent superior properties of SUVs and limits their effectiveness in practical applications. Therefore, achieving efficient and uniform dispersion of SUVs in solvents or matrices, especially by unbundling them into whole tubes while maintaining their aspect ratio, is a key technical challenge in preparing high-performance SUV conductive pastes.

[0008] Therefore, developing a highly efficient industrial dispersion process for single-walled carbon nanotubes, while ensuring the high conductivity of the finished slurry and the environmental friendliness of the production process, is an urgent problem that needs to be solved. Summary of the Invention

[0009] This invention addresses the problems of single-walled carbon nanotubes (SUVs) being difficult to disperse as a whole, affecting the conductivity of the finished slurry; the complexity and environmental unfriendliness of dispersants limiting the application range of the finished slurry; the complexity, low efficiency, and high cost of industrial production processes; and the current microfluidic homogenization technology used to disperse SUVs, which generally suffers from high homogenization pressure, low efficiency, high equipment requirements, significant breakage of SUVs, easy agglomeration of SUVs in the slurry, and uneven dispersion.

[0010] This invention provides a method for efficiently preparing single-walled carbon nanotube slurry. The method involves impregnating, mixing, pre-dispersing, and high-pressure exfoliation of single-walled carbon nanotubes to form a uniformly dispersed slurry. Simultaneously, by altering the type of high-pressure microchannels and using a dispersant during the high-pressure exfoliation process, the single-walled carbon nanotubes can be efficiently dispersed. This process, combined with a microfluidic high-pressure homogenizer, can be industrialized, effectively solving problems such as complex industrial production processes, high homogenization and dispersion pressures, and low efficiency.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: A method for efficiently preparing single-walled carbon nanotube slurry, the specific steps of which are as follows: 1. Feeding: Place a certain amount of single-walled carbon nanotube powder, dispersant, and solvent into a mixing tank. The single-walled carbon nanotubes account for 0.1%-1% of the mass, the dispersant accounts for 0.5%-1.5% of the mass, and the solvent accounts for 97.5%-99.5% of the mass.

[0012] 2. Premix and stir, turn on the stirring tank to disperse at high speed, and after stirring and dispersion are completed, a uniformly mixed carbon nanotube bundle slurry is obtained; 3. Microjets homogenize the carbon nanotube bundle slurry obtained after premixing and stirring. The slurry is then passed through a high-pressure microjets homogenizer multiple times to achieve uniform dispersion of individual carbon nanotubes. The microjets homogenizing channels consist of a combination of microjets turbulent channels and conventional channels; the conventional channel types are one or more of the following: "Z", "Y", "H", and "K".

[0013] 4. Sieve the material through a sieve with a mesh size of 60-300 to obtain the finished slurry of single-walled carbon nanotubes.

[0014] Furthermore, in step 1, the dispersant is one of CMC (carboxymethyl cellulose), PVDF (polyvinylidene fluoride), and PVP (polyvinylpyrrolidone); the solvent is one of NMP (N-methylpyrrolidone), pure water, ethanol, and isopropanol.

[0015] Furthermore, in step 2, the high-speed dispersion adopts emulsification dispersion or high-speed stirring dispersion; wherein the high-speed stirring dispersion time is 2-10h, the high-speed stirring dispersion speed is 600rpm-3000rpm, and the dispersion disc diameter is 40mm-400mm; the emulsification dispersion time is 1-6h, the emulsification dispersion shear rate is 0.5krpm-20krpm, the emulsification dispersion stator diameter is 40mm-350mm, and the emulsification motor or high-speed dispersion motor power is 0.8kw-35kw.

[0016] Furthermore, in step 3, the carbon nanotube bundle slurry obtained after premixing and stirring is first passed through a turbulent homogenizing channel and then through a conventional channel; the number of channels in series in the high-pressure micro-jet homogenizer is 2-4; the number of homogenizing channels in the micro-jet homogenizer is 2-8, and the pressure of the micro-jet homogenizer is 500 bar-2000 bar.

[0017] Furthermore, in step 3, the microjet turbulence channel includes a first turbulence structure 1 and a second turbulence structure 2 connected in series, or includes two first turbulence structures 1 connected in series, or includes two second turbulence structures 2 connected in series; The first turbulent junction structure 1 includes a plurality of stepped holes 11 connected sequentially along the slurry flow direction and with gradually decreasing diameters; the second turbulent junction structure 2 includes an expansion hole 21, a constant diameter hole 22, and a narrowing diameter hole 23 connected sequentially along the slurry flow direction; the diameter of the expansion hole 21 gradually increases along the slurry flow direction, the diameter of the narrowing diameter hole 23 gradually decreases along the slurry flow direction, and the maximum diameter of both the narrowing diameter hole 23 and the narrowing diameter hole is equal to the diameter of the constant diameter hole 22.

[0018] In the first turbulent junction structure 1, the ratio of the diameter of the largest stepped hole 11 to the diameter of the smallest stepped hole 11 is ≥3; in the second turbulent junction structure, the contraction angle α or expansion angle β is ≥50° and ≤150°. The minimum diameter of the stepped hole 11, the expanded hole 21, the equal diameter hole 22, and the reduced diameter hole 23 is ≤1000μm and ≥0.1μm, and the maximum diameter of the stepped hole 11, the expanded hole 21, the equal diameter hole 22, and the reduced diameter hole 23 is ≤10mm and ≥1μm.

[0019] This invention requires only 2-8 homogenization stages to achieve the desired dispersion, resulting in high dispersion efficiency and minimal damage to single-walled carbon nanotubes. The number of homogenization stages using the microfluidic homogenizer depends on the desired dispersion effect of the slurry. Generally, aqueous slurries with a particle size D50 ≤ 0.1 μm and NMP slurries with a particle size D50 ≤ 1 μm achieve the best dispersion effect. The more intact the carbon nanotubes, the less damage, and the better the conductivity of the slurry.

[0020] Compared with the prior art, the advantages of the present invention are as follows: 1. This invention introduces a turbulent channel with a specific geometric shape (variable diameter) and combines it in a specific series connection with a traditional homogeneous channel (such as a Z-valve). Compared to other channels, the turbulent channel has a variable diameter, meaning the fluid's internal effect is not limited to the fluid impact effects of other types of channels. This structure allows the slurry to generate fluid turbulence when passing through the turbulent channel under high pressure in a microjet. The turbulent micro-clusters not only exhibit lateral pulsation but also a reverse motion relative to the overall fluid motion. This micro-cluster motion not only enhances the mixing and dispersion of the slurry but also facilitates the opening of entangled single-walled carbon nanotubes during the slurry's impact process, making it easier for the dispersant to adhere to the surface of the single-walled carbon nanotubes. This allows for easier and more complete opening of the single-walled carbon nanotubes as the slurry enters subsequent channels in the microjet. Furthermore, the turbulent channel has a larger aperture than conventional microjet channels, which can act as a pre-break-up mechanism, preventing frequent clogging of the microchannels. This improves equipment uptime and practicality. By combining turbulent channels with other types of microjet channels, only 2-8 channels are needed to achieve the dispersion requirements, resulting in efficient dispersion of single-walled carbon nanotubes with minimal damage to the single-walled carbon nanotubes. This invention is adaptable to different dispersants and solvent systems.

[0021] 2. The process is simple, with few control parameters, making it suitable for large-scale mass production. It does not require expensive or special dispersants; single-walled carbon nanotube powder is dispersed into a uniform, complete single-walled carbon nanotube slurry through only two simple dispersion steps.

[0022] 3. Thorough dispersion and good stability of the finished slurry. The unique homogenizing channel of this invention, combined with appropriate homogenizing pressure, produces a finished single-walled carbon nanotube slurry with good stability and excellent electrical conductivity. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the turbulent channel of a microjet homogenizer; Figure 2 This is a transmission electron microscope (TEM) image of the finished single-walled carbon nanotube slurry from Example 1; Figure 3 The graph shows the particle size variation of the slurry after microjet homogenization in Examples 1, 2, 3 and Comparative Examples 1, 2, 3 and 4.

[0024] In the figure: 1-first turbulent structure, 11-stepped hole, 2-second turbulent structure, 21-expansion hole, 22-equal diameter hole, 23-reduced diameter hole. Detailed Implementation

[0025] The present invention will be further described in detail below through specific embodiments, but the present invention is not limited to the following specific embodiments.

[0026] Implementation

[0027] Example 1: The specific steps of a method for efficiently preparing single-walled carbon nanotube slurry are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0028] 2. A 3kW dispersing motor and a 100mm diameter dispersing disc were used. High-speed dispersion was initiated, and the rotation speed was adjusted to 1500rpm. Dispersion was carried out for 4 hours to obtain a single-walled carbon nanotube bundle slurry. The particle size D50 measured by a laser particle size analyzer was 392μm. 3. Install the turbulent homogenizing channel and the "Z"-shaped homogenizing channel in sequence into the micro-jet channel, adjust the homogenizing pressure to 1000 bar, place the slurry obtained in step 2 into the feed tank of the micro-jet homogenizer, and turn on the micro-jet homogenizer. After the slurry in the feed tank has completely passed through the micro-jet homogenizer into the discharge tank, the slurry in the discharge tank is poured back into the feed tank, and the slurry is repeatedly passed through the micro-jet homogenizer four times and sieved through a 60-mesh screen to obtain a uniform single-walled carbon nanotube slurry with a particle size D50 of 0.083 μm. The micro-jet turbulence channel consists of a first turbulence structure 1 and a second turbulence structure 2 connected in series. The first turbulence structure 1 includes multiple stepped holes 11 connected in sequence along the slurry flow direction with gradually decreasing pore size. The second turbulence structure 2 includes an expansion hole 21, an equal diameter hole 22, and a narrowing hole 23 connected in sequence along the slurry flow direction. The pore size of the expansion hole 21 gradually increases along the slurry flow direction, and the pore size of the narrowing hole 23 gradually decreases along the slurry flow direction. The maximum pore size of the narrowing hole 23 and the maximum pore size of the narrowing hole 23 are both equal to the pore size of the equal diameter hole 22.

[0029] 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 0.083 μm, and the viscosity was 2384 mPa•s. When added to the silicon system at 0.1% by mass of the effective component, the resistivity of the electrode was tested to be 109.22 Ω•cm. In contrast, the resistivity of pure silicon powder electrode without the addition of conductive agent is >10000 Ω•cm.

[0030] Example 2: The specific steps of a method for efficiently preparing single-walled carbon nanotube slurry are as follows: 1. Prepare 50g of single-walled carbon nanotube powder, 150g of PVDF powder, and 9.8kg of NMP solvent and put them into a dispersion tank.

[0031] 2. The dispersion motor is 4.5kw, the rotor stator diameter of the emulsification head is 120mm, the emulsification dispersion is turned on, the speed is adjusted to 12krpm, and the dispersion is carried out for 3h to obtain single-walled carbon nanotube bundle slurry (the particle size D50 measured by laser particle size analyzer is 198.1μm). 3. Install a turbulent homogenizing channel and a "Y"-shaped homogenizing channel sequentially into the microjet channel. Adjust the homogenization pressure to 1500 bar. Place the slurry obtained in step 2 into the feed tank of the microjet homogenizer and turn on the microjet homogenizer. Wait for the slurry in the feed tank to completely pass through the microjet homogenizer and enter the discharge tank. Pour the slurry from the discharge tank back into the feed tank, allowing the slurry to repeatedly pass through the microjet homogenizer 6 times. Sieve through a 60-mesh sieve to obtain a uniform single-walled carbon nanotube slurry with a particle size D50 of 0.797 μm. The microjet turbulence channel consists of a first turbulence structure 1 and a second turbulence structure 2 connected in series. The first turbulence structure 1 includes a plurality of stepped holes 11 connected in sequence along the slurry flow direction with gradually decreasing diameters. The second turbulence structure 2 includes an expansion hole 21, a constant diameter hole 22, and a narrowing diameter hole 23 connected in sequence along the slurry flow direction. The diameter of the expansion hole 21 gradually increases along the slurry flow direction, and the diameter of the narrowing diameter hole 23 gradually decreases along the slurry flow direction. The maximum diameter of both the narrowing diameter hole 23 and the constant diameter hole 22 are equal to the diameter of the constant diameter hole 22.

[0032] 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 0.797 μm and the viscosity was 2480 mPa•s. When added to ternary NCM523 at 0.1% by mass of the effective component, the resistivity of the electrode was tested to be 4.99 Ω•cm.

[0033] (The resistivity of pure ternary NCM523 electrode without added conductive agent is >1000Ω•cm) Example 3: The specific steps of a method for efficiently preparing single-walled carbon nanotube slurry are as follows: 1. Prepare 20g of single-walled carbon nanotube powder, 80g of PVP powder, and 9.9kg of pure water and put them into a dispersion tank.

[0034] 2. The dispersion motor is 4.5kw, the rotor stator diameter of the emulsification head is 120mm, the emulsification dispersion is turned on, the speed is adjusted to 12krpm, and the dispersion is carried out for 2 hours to obtain single-walled carbon nanotube bundle slurry (the particle size D50 measured by laser particle size analyzer is 342.5μm). 3. Sequentially load a turbulent homogenizing channel, a "Z"-type homogenizing channel, and a "Y"-type homogenizing channel into the microjet channel. Adjust the homogenization pressure to 2000 bar. Place the slurry obtained in step 2 into the feed tank of the microjet homogenizer and turn on the microjet homogenizer. Wait for the slurry in the feed tank of the microjet homogenizer to completely pass through the microjet homogenizer and enter the discharge tank. Pour the slurry in the discharge tank back into the feed tank, allowing the slurry to repeatedly pass through the microjet homogenizer 5 times and be sieved through a 60-mesh sieve to obtain a uniform single-walled carbon nanotube slurry with a particle size D50 of 0.067 μm. The microjet turbulence channel consists of a first turbulence structure 1 and a second turbulence structure 2 connected in series. The first turbulence structure 1 includes a plurality of stepped holes 11 connected in sequence along the slurry flow direction with gradually decreasing diameters. The second turbulence structure 2 includes an expansion hole 21, a constant diameter hole 22, and a narrowing diameter hole 23 connected in sequence along the slurry flow direction. The diameter of the expansion hole 21 gradually increases along the slurry flow direction, and the diameter of the narrowing diameter hole 23 gradually decreases along the slurry flow direction. The maximum diameter of both the narrowing diameter hole 23 and the constant diameter hole 22 are equal to the diameter of the constant diameter hole 22.

[0035] 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 0.067 μm, the viscosity was 2837 mPa•s, and the resistivity of the electrode was 211.67 Ω•cm when added to the silicon system at 0.1% of the effective component.

[0036] Comparative Example 1: The specific steps are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0037] 2. With a 3kW dispersing motor and a 100mm diameter dispersing disc, start high-speed dispersing and adjust the speed to 1500rpm. Disperse for 4 hours to obtain single-walled carbon nanotube bundle slurry.

[0038] 3. Only a "Z"-shaped homogenizing channel is installed in the microjets. The homogenizing pressure is adjusted to 1000 bar. The slurry obtained in step 2 is placed in the feed tank of the microjets homogenizer, and the microjets homogenizer is turned on. Wait for the slurry in the feed tank to completely pass through the microjets homogenizer and enter the discharge tank. Pour the slurry from the discharge tank back into the feed tank, allowing the slurry to pass through the microjets homogenizer five times. Sieve through a 60-mesh sieve to obtain a single-walled carbon nanotube slurry with a particle size D50 of 10.37 μm. The slurry continues to pass through the microjets homogenizer at 1000 bar pressure. The particle size of the slurry tested at the 10th test is 5.454 μm, the particle size of the slurry tested at the 15th test is 5.138 μm, and the particle size of the slurry tested at the 20th test is 4.899 μm. 4. Take homogenized slurry samples from the 5th and 20th passes. The particle size D50 of the slurry was found to be 10.37 μm and 4.899 μm, respectively, and the viscosity was 4596 mPa•s and 4373 mPa•s, respectively. When added to the silicon system at 0.1% of the effective component, the electrode resistivity values ​​were 1108.96 Ω•cm and 852.72 Ω•cm, respectively.

[0039] Comparative Example 2: The specific steps are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0040] 2. With a 3kW dispersing motor and a 100mm diameter dispersing disc, start high-speed dispersing and adjust the speed to 1500rpm. Disperse for 4 hours to obtain single-walled carbon nanotube bundle slurry.

[0041] 3. Install only a turbulent homogenizing channel (structure same as in Example 1) in the microjet channel, adjust the homogenizing pressure to 1000 bar, place the slurry obtained in step 2 into the feed tank of the microjet homogenizer, and turn on the microjet homogenizer. Wait for the slurry in the feed tank of the microjet homogenizer to completely pass through the microjet homogenizer and enter the discharge tank, pour the slurry in the discharge tank into the feed tank, and repeat the process of passing the slurry through the microjet homogenizer 10 times and sieving it through a 60-mesh sieve to obtain a relatively uniform single-walled carbon nanotube slurry with a particle size D50 of 0.096 μm.

[0042] 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 0.096 μm, the viscosity was 2590 mPa•s, and the resistivity of the electrode was 153.7 Ω•cm when added to the silicon system at 0.1% of the effective component.

[0043] Comparative Example 3: The specific steps are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0044] 2. With a 3kW dispersing motor and a 100mm diameter dispersing disc, start high-speed dispersing and adjust the speed to 1500rpm. Disperse for 4 hours to obtain single-walled carbon nanotube bundle slurry.

[0045] 3. Insert a Z-shaped homogenizing channel and a turbulent homogenizing channel (structure same as in Example 1) sequentially into the microjets. Adjust the homogenization pressure to 1000 bar. Place the slurry obtained in step 2 into the feed tank of the microjets homogenizer and turn on the microjets homogenizer. Wait for the slurry in the feed tank to completely pass through the microjets homogenizer and enter the discharge tank. Pour the slurry from the discharge tank back into the feed tank, allowing the slurry to pass through the microjets homogenizer four times. Sieve through a 60-mesh sieve to obtain a relatively uniform single-walled carbon nanotube slurry with a particle size D50 of 6.157 μm.

[0046] 4. The particle size D50 of the finished slurry obtained in this embodiment was found to be 6.157 μm and the viscosity was 4872 mPa•s. When added to the silicon system at 0.1% of the effective component, the resistivity of the electrode was tested to be 870.52 Ω•cm.

[0047] Comparative Example 4: The specific steps are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0048] 2. With a 3kW dispersing motor and a 100mm diameter dispersing disc, start high-speed dispersing, adjust the speed to 1500rpm, and disperse for 4 hours to obtain single-walled carbon nanotube bundle slurry; 3. Only install a "Z"-shaped homogenizing channel in the microjets, adjust the homogenizing pressure to 2500 bar, place the slurry obtained in step 2 into the feed tank of the microjets homogenizer, and turn on the microjets homogenizer. Wait for the slurry in the feed tank of the microjets homogenizer to completely pass through the microjets homogenizer and enter the discharge tank. Pour the slurry in the discharge tank back into the feed tank, allowing the slurry to repeatedly pass through the microjets homogenizer 12 times and be sieved through a 60-mesh sieve to obtain a relatively uniform single-walled carbon nanotube slurry with a particle size D50 of 1.627 μm. 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 1.627 μm, the viscosity was 4144 mPa•s, and the resistivity of the electrode was 622.77 Ω•cm when added to the silicon system at 0.1% of the effective component.

[0049] Comparative Example 5: The specific steps are as follows: 1. Prepare 40g of single-walled carbon nanotube powder, 60g of CMC powder, and 9.9kg of pure water and put them into a dispersion tank.

[0050] 2. With a 3kW dispersing motor and a 100mm diameter dispersing disc, start high-speed dispersing, adjust the speed to 1500rpm, and disperse for 4 hours to obtain single-walled carbon nanotube bundle slurry; 3. Homogenize the slurry obtained in step 2 using a conventional collision valve-type homogenizing chamber. Adjust the homogenization pressure to 1000 bar, place the slurry obtained in step 2 into the feed tank of a conventional homogenizer, and turn on the conventional homogenizer. Wait for the slurry in the feed tank of the conventional homogenizer to completely pass through the conventional homogenizer and enter the discharge tank, then pour the slurry in the discharge tank into the feed tank, and repeat the process of passing the slurry through the conventional homogenizer 10 times and sieving it through a 60-mesh sieve to obtain a relatively uniform single-walled carbon nanotube slurry with a particle size D50 of 0.085 μm; 4. The particle size D50 of the finished slurry obtained in this embodiment was tested to be 0.085 μm, the viscosity was 2128 mPa•s, and when added to the silicon system at 0.1% of the effective component, the resistivity of the electrode was tested to be 1266.57 Ω•cm.

[0051] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for efficiently preparing single-walled carbon nanotube slurry, characterized in that: The preparation steps are as follows: (1) Feeding: Place the single-walled carbon nanotube powder, dispersant, and solvent into a mixing tank; (2) Premix, turn on the stirring tank to disperse, and after stirring and dispersing, a uniformly mixed carbon nanotube bundle slurry is obtained; (3) After premixing, the carbon nanotube bundle slurry is passed through a high-pressure microjet homogenizer multiple times to obtain a uniform, single carbon nanotube slurry after dispersion; the microjet homogenizing channel combination is obtained by combining turbulent homogenizing channels and conventional homogenizing channels; the conventional homogenizing channel type is one or more of Z-type, Y-type, H-type, and K-type; the microjet turbulent channel includes a first turbulent structure and a second turbulent structure in series, or includes two first turbulent structures in series, or includes two second turbulent structures in series; The first turbulent structure includes a plurality of stepped holes connected sequentially along the slurry flow direction, with the hole diameter gradually decreasing; the second turbulent structure includes an expansion hole, a constant diameter hole, and a narrowing diameter hole connected sequentially along the slurry flow direction; the hole diameter of the expansion hole gradually increases along the slurry flow direction, the hole diameter of the narrowing diameter hole gradually decreases along the slurry flow direction, and the maximum hole diameter of both the narrowing diameter hole and the narrowing diameter hole is equal to the hole diameter of the constant diameter hole. (4) Sieve to obtain single-walled carbon nanotube slurry.

2. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (1), by mass percentage, the single-walled carbon nanotube powder accounts for 0.1%-1%, the dispersant accounts for 0.5%-1.5%, and the solvent accounts for 97.5%-99.5%, with the sum of the three mass fractions being 100%.

3. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (1), the dispersant is one of carboxymethyl cellulose, polyvinylidene fluoride, or polyvinylpyrrolidone.

4. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (1), the solvent is one of NMP, pure water, ethanol, and isopropanol.

5. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (2), the premixed dispersion adopts emulsification dispersion or high-speed stirring dispersion; the high-speed stirring dispersion time is 2-10h, the high-speed stirring dispersion speed is 600rpm-3000rpm, and the dispersion disc diameter is 40mm-400mm; the emulsification dispersion time is 1-6h, the emulsification dispersion shear speed is 0.5krpm-20krpm, and the emulsification dispersion stator diameter is 40mm-350mm; the emulsification motor or high-speed dispersion motor power is 0.8kw-35kw.

6. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (3), the carbon nanotube bundle slurry obtained after premixing and stirring is first passed through a turbulent homogeneous channel and then through a conventional channel.

7. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: In step (3), the number of channels connected in series in the high-pressure microjet homogenizer is 2-4.

8. The method for efficiently preparing single-walled carbon nanotube slurry according to claim 1, characterized in that: The number of homogenization channels in the microjet homogenizer is 2-8, and the pressure of the microjet homogenizer is 500bar-2000bar.

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