High-conductivity low-viscosity single-walled carbon nanotube conductive paste, preparation method and application thereof

Abstract

This invention discloses a highly conductive, low-viscosity single-walled carbon nanotube conductive slurry, its preparation method, and its applications, belonging to the field of conductive materials technology. The single-walled carbon nanotube conductive slurry, by mass parts, comprises the following components: 3-8 parts single-walled carbon nanotubes, 1-5 parts composite dispersant, 0.5-3 parts viscosity modifier, 0.1-1 parts anti-agglomeration agent, and 83-95 parts solvent. The preparation method involves first gently pre-dispersing to prevent carbon nanotube breakage, then using gradient grinding and high-pressure homogenization to achieve uniform dispersion of the carbon nanotubes, and finally vacuum degassing to remove air bubbles from the system, further reducing viscosity and improving stability. The conductive slurry prepared by this invention has a room temperature viscosity ≤2000 mPa·s and a volume resistivity ≤5×10⁻⁶. ‑3 With a strength of Ω·cm, excellent dispersion stability, and metal impurity residue ≤20 ppm, it can be widely used in power batteries, consumer electronics, flexible electronics, thermal interface materials and other fields.

Description

Technical Field

[0001] This invention belongs to the field of conductive materials technology, specifically relating to a highly conductive, low-viscosity single-walled carbon nanotube conductive paste, its preparation method, and its application, particularly a high-performance single-walled carbon nanotube conductive paste suitable for new energy power batteries and flexible electronics. Background Technology

[0002] Single-walled carbon nanotubes, due to their unique one-dimensional nanostructure, extremely high aspect ratio, and excellent electrical conductivity and mechanical properties, can construct a continuous three-dimensional conductive network with extremely low addition amounts compared to traditional conductive additives such as multi-walled carbon nanotubes and carbon black. They are widely used in the preparation of conductive pastes, especially in the field of new energy power batteries, where they can effectively improve the electronic conduction efficiency of electrodes, suppress the volume expansion of active materials, and improve the cycle performance and rate performance of batteries.

[0003] However, the preparation and application of single-walled carbon nanotube conductive pastes still face many technical bottlenecks, making it difficult to simultaneously meet the core requirements of high conductivity and low viscosity. On the one hand, due to their extremely strong van der Waals forces, single-walled carbon nanotubes are prone to agglomeration and entanglement, requiring the addition of a large amount of dispersant or high-intensity mechanical dispersion. This leads to increased paste viscosity and poor flowability, affecting subsequent industrial operations such as electrode coating and printing. On the other hand, reducing the amount of dispersant or weakening the mechanical dispersion intensity to lower viscosity will result in the inability to effectively break up carbon nanotube agglomerates, leading to discontinuous conductive networks and reduced paste conductivity. Furthermore, the presence of agglomerates also results in poor paste dispersion stability, making it prone to stratification and precipitation during long-term storage.

[0004] In addition, the existing technology has the following problems: First, the residual metal catalyst in the single-walled carbon nanotube raw material is high (usually higher than 50 ppm), which can cause side reactions inside the battery and affect battery safety and cycle life; Second, the dispersants are mostly single systems, making it difficult to achieve efficient dispersion of carbon nanotubes and precise control of slurry viscosity at the same time, and some dispersant residues will affect the electrochemical performance of the slurry; Third, the high-intensity grinding and homogenization processes used in the preparation process can easily damage the length and structural integrity of single-walled carbon nanotubes, reduce their aspect ratio, and thus weaken the ability to build conductive networks; Fourth, the batch consistency of the slurry is poor, with viscosity fluctuation coefficients exceeding ±8% and conductivity standard deviations greater than 15%, making it difficult to meet the stringent requirements of leading power battery customers.

[0005] Existing patents (such as CN119763899A) propose methods for preparing high-solids-content single-walled carbon nanotube aqueous conductive pastes, using three-roll milling to shorten the carbon nanotubes and reduce dispersion difficulty. However, the shortened carbon nanotubes have a lower aspect ratio, resulting in some loss of conductivity. Furthermore, these methods focus on high solids content and do not address the synergistic issue of achieving high conductivity and low viscosity. Meanwhile, with the development of the new energy industry, the performance requirements for conductive pastes in fields such as power batteries and flexible electronics are constantly increasing. These pastes need excellent conductivity to reduce electrode internal resistance, low viscosity to adapt to high-speed coating and fine printing processes, and stable dispersion with low impurity residue. Therefore, developing a high-conductivity, low-viscosity, high-stability, and low-impurity single-walled carbon nanotube conductive paste and its preparation method has become an urgent technical problem to be solved in this field. Summary of the Invention

[0006] To address the technical problems of existing single-walled carbon nanotube conductive pastes, such as difficulty in achieving a balance between conductivity and viscosity, poor dispersion stability, high residual metal impurities, easy damage to carbon nanotube structures, and poor batch consistency, the first objective of this invention is to provide a single-walled carbon nanotube conductive paste with high conductivity and low viscosity. The single-walled carbon nanotube conductive paste provided by this invention features high conductivity, low viscosity, and high stability.

[0007] The second objective of this invention is to provide a method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste. The preparation method of this invention is simple and controllable, produces low-impurity residues, is suitable for industrial production, and meets the application needs of multiple downstream fields.

[0008] The third objective of this invention is to provide an application of a highly conductive, low-viscosity single-walled carbon nanotube conductive paste. It is particularly suitable for applications related to new energy power batteries and flexible electronics.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] This invention discloses a highly conductive and low-viscosity single-walled carbon nanotube conductive slurry, which comprises, by mass parts: 3-8 parts of single-walled carbon nanotubes, 1-5 parts of composite dispersant, 0.5-3 parts of viscosity modifier, 0.1-1 parts of anti-agglomeration agent, and 83-95 parts of solvent.

[0011] The composite dispersant is composed of sodium carboxymethyl cellulose and comb-shaped polyamide lithium salt;

[0012] The viscosity modifier is a compound of multifunctional amine additive AMP-95 and polyethylene glycol;

[0013] The anti-agglomeration agent is nano-silica and / or graphene quantum dots.

[0014] The single-walled carbon nanotube conductive slurry provided by this invention comprises a composite dispersant composed of sodium carboxymethyl cellulose and comb-shaped lithium polyamide, which enables efficient dispersion of single-walled carbon nanotubes while avoiding the viscosity increase problem caused by a single dispersant, thus balancing dispersibility and low viscosity requirements. The viscosity modifier is composed of a multifunctional amine additive and polyethylene glycol, which can precisely control the slurry viscosity, while improving the slurry's fluidity and stability and preventing slurry stratification. The anti-agglomeration agent is selected from nano-silica and / or graphene quantum dots, which can form steric hindrance on the carbon nanotube surface, inhibiting carbon nanotube agglomeration and extending the slurry's storage period. With the synergistic effect of the above components, single-walled carbon nanotubes can be stably and uniformly dispersed for a long time, exhibiting high conductivity and high stability.

[0015] In a preferred embodiment, the single-walled carbon nanotube conductive slurry comprises, by weight, the following components: 5-6 parts single-walled carbon nanotubes, 2-3 parts composite dispersant, 1-2 parts viscosity modifier, 0.3-0.6 parts anti-agglomeration agent, and 88-92 parts solvent. This preferred formulation achieves a better balance between conductivity and viscosity while ensuring dispersion stability.

[0016] In a preferred embodiment, the single-walled carbon nanotubes have a residual metal impurity concentration of ≤20 ppm, a diameter of 1.3~2.0 nm, an aspect ratio of ≥2000:1, a Raman G / D ratio of ≥90, and a specific surface area of ​​≥100 m² / g. The single-walled carbon nanotubes provided by this invention are purified single-walled carbon nanotubes, possessing excellent conductivity and structural integrity.

[0017] In a preferred embodiment, the single-walled carbon nanotubes are prepared by arc electrolysis or CVD. Preferably, the crude single-walled carbon nanotubes obtained by arc electrolysis are purified. The purification process is as follows: the crude single-walled carbon nanotubes are placed in an acid solution containing a complexing agent for acidification treatment, followed by solid-liquid separation. The resulting solid product is then placed in a water vapor atmosphere for high-temperature water oxidation treatment to obtain an oxidation product. The oxidation product is then dispersed in a dispersion medium for multi-stage centrifugal separation. The supernatant is collected and dried to obtain the purified single-walled carbon nanotubes.

[0018] The process for obtaining single-walled carbon nanotubes in this invention is as follows: First, the crude product of single-walled carbon nanotubes prepared by arc method or CVD method is placed in an acid solution containing a complexing agent for acidification treatment. On the one hand, the acid removes some amorphous carbon, and on the other hand, the metal catalyst impurities exposed on the surface of the single-walled carbon nanotubes are dissolved into metal ions. The metal ions in the solution are captured and stabilized by the complexing agent, effectively preventing their redeposition. Then, the solid product obtained by acidification treatment is placed in a water vapor atmosphere for high-temperature water oxidation treatment. The weak oxidizing property of water vapor is used to selectively remove residual amorphous carbon, carbon nanoparticles and other carbon impurities. At the same time, the graphite layer encapsulating the catalyst particles, that is, the outer graphite layer of the carbon-coated metal structure, is destroyed, exposing the encapsulated iron, cobalt, nickel and other catalyst particles, which are then converted into metal oxides. Finally, the impurities are separated by multi-stage centrifugation to obtain purified single-walled carbon nanotubes.

[0019] In a further preferred embodiment, the acid solution containing the complexing agent is composed of the complexing agent and an acid solution, wherein the acid solution is selected from hydrochloric acid and / or nitric acid, preferably hydrochloric acid.

[0020] In a further preferred embodiment, the complexing agent is composed of sodium citrate and EDTA, wherein the amount of sodium citrate added is 0.1%-5% of the mass of the acid solution, preferably 0.5%-2%; the amount of EDTA added is 0.1%-5% of the mass of the acid solution, preferably 0.5%-2%; and the mass ratio of sodium citrate to EDTA is 1-2:1-2.

[0021] In this invention, sodium citrate and EDTA are added as a two-component complexing agent. Sodium citrate has multiple carboxyl and hydroxyl groups, enabling it to form stable five- or six-membered ring chelates with metal ions. EDTA is a well-known hexadecantal ligand with extremely high complexing constants with metal ions, for example, logK≈25 with Fe³⁺. The synergistic effect of both agents efficiently captures and stabilizes metal ions in solution, effectively preventing their redeposition. Simultaneously, sodium citrate also has a dispersing effect, facilitating the uniform dispersion of carbon nanotubes in acidic solutions and improving the contact efficiency between the acid and metal impurities.

[0022] Further preferably, the hydrochloric acid has a mass concentration of 5%-37%, preferably 15%-25%; and the nitric acid has a mass concentration of 10%-68%.

[0023] In a further preferred embodiment, when the acid solution is selected from hydrochloric acid and nitric acid, the volume ratio of hydrochloric acid to nitric acid is 1-3:1-3.

[0024] In practice, single-walled carbon nanotubes can be added to a mixed acid solution first, and then a complexing agent can be added after the mixed acid solution is heated to the treatment temperature. Alternatively, the complexing agent can be mixed with the mixed acid solution before adding the single-walled carbon nanotubes.

[0025] In a further preferred embodiment, the solid-liquid mass-volume ratio of the single-walled carbon nanotube powder to the acid solution containing the complexing agent is 1g:50-500mL.

[0026] In a further preferred embodiment, the acidification treatment temperature is 60℃-120℃, and the acidification treatment time is 2-24h.

[0027] More preferably, the acidification treatment is carried out under stirring. Stirring during the acidification process ensures that the complexing agent comes into full contact with the dissolved metal ions.

[0028] More preferably, the acidification treatment is carried out at a temperature of 80℃-100℃ for 6-12 hours under reflux conditions. The high-temperature reflux conditions during the acid treatment can effectively remove some amorphous carbon impurities and introduce an appropriate amount of oxygen-containing functional groups into the carbon nanotube wall, which is beneficial for dispersion in subsequent steps.

[0029] In a further preferred embodiment, the solid-liquid separation method is centrifugation, with a centrifugal force of 1000g-5000g and a centrifugation time of 10-60min.

[0030] In a further preferred embodiment, the solid phase obtained from the solid-liquid separation is first pre-dried and then placed in a water vapor atmosphere for high-temperature water oxidation treatment. The temperature of the pre-drying treatment is 80℃-120℃, and the pre-drying treatment time is 2-6 hours.

[0031] In a further preferred embodiment, the water vapor atmosphere is formed by heating and evaporating deionized water and then introducing it into the reactor as a carrier gas; the water vapor concentration is 5 vol%-30 vol%, preferably 10 vol%-20 vol%.

[0032] More preferably, the carrier gas is selected from argon or nitrogen, and the flow rate of the carrier gas is 100-500 mL / min, preferably 200-300 mL / min.

[0033] In a further preferred embodiment, the high-temperature water oxidation treatment is performed at a temperature of 800-900℃ for a duration of 0.5-3 hours.

[0034] Further optimization involves using a high-temperature water oxidation treatment at a temperature of 830-870℃ for 1-2 hours.

[0035] In a further preferred embodiment, the oxidation product is added to the dispersion medium, and the oxidation product is dispersed in the dispersion medium by ultrasonic treatment. During the ultrasonic treatment, the ultrasonic power is controlled at 100-800 W and the ultrasonic time is 10-60 min to fully disperse the carbon nanotube bundles.

[0036] Further preferably, the dispersion medium comprises water. In actual operation, deionized water is used.

[0037] More preferably, the dispersion medium further comprises a surfactant selected from at least one of sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), sodium deoxycholate (DOC), or Triton X-100, and the concentration of the surfactant in the dispersion medium is 0.1-5 wt%.

[0038] In a further preferred embodiment, the multi-stage centrifugal separation process includes at least two stages of centrifugal separation. The centrifugal force of the first stage centrifugation is 1000g-5000g, preferably 2000g-3000g, and the centrifugation time is 15-60min, preferably 20-40min. After the first centrifugation is completed, the lower precipitate is collected and then dispersed in a dispersion medium for the second centrifugation. The centrifugal force of the second stage centrifugation is 10000g-30000g, preferably 15000g-25000g, and the centrifugation time is 30-120min, preferably 40-80min. After the second centrifugation is completed, the supernatant is collected.

[0039] In this invention, the multi-stage centrifugal fractionation process includes at least two stages of centrifugal separation under different centrifugal force conditions. The first stage of centrifugation uses a lower centrifugal force to suspend light impurities such as amorphous carbon with lower density in the supernatant, and the lower precipitate is collected. After redispersing the lower precipitate, a second stage of centrifugation is performed using a higher centrifugal force to cause carbon nanoparticles and metal oxide impurities with higher density to settle, and the supernatant is collected to obtain a purified single-walled carbon nanotube dispersion.

[0040] In a further preferred embodiment, the lower precipitate is added to the dispersion medium, and the lower precipitate is dispersed in the dispersion medium by ultrasonic treatment, wherein the ultrasonic power is controlled at 100-800 W and the ultrasonic time is 10-60 min.

[0041] In a further preferred embodiment, the drying process is one of vacuum drying, freeze drying, or spray drying, with a drying temperature of 60℃-120℃ and a drying time of 6-24 hours. During vacuum drying, the vacuum degree is controlled to be -0.09~-0.1MPa.

[0042] In a preferred embodiment, the mass ratio of sodium carboxymethyl cellulose to comb-shaped polyamide lithium salt in the composite dispersant is 2.5~3:1.

[0043] In this invention, the degree of substitution of sodium carboxymethyl cellulose is 0.55~1.05. The comb-shaped polyamide lithium salt can be prepared using conventional methods, such as: dissolving methoxy polyetheramine and 3,3,4,4-benzophenone tetracarboxylic dianhydride separately in N,N-dimethylformamide to obtain a 35wt% methoxy polyetheramine solution and a 9.5wt% 3,3,4,4-benzophenone tetracarboxylic dianhydride solution; adding the methoxy polyetheramine solution to a reaction vessel, and dropwise adding the 3,3,4,4-benzophenone tetracarboxylic dianhydride solution at 45~50℃ and 200~300 r / min; after the addition is complete, adding lithium carbonate, and stirring the reaction at 70~75℃ for 2.5~3 minutes. h, cool to -10℃, filter, and remove the solvent by rotary evaporation of the filtrate to obtain comb-shaped polyamide lithium salt; wherein the ratio of methoxy polyetheramine solution, 3,3,4,4-benzophenone tetracarboxylic dianhydride solution and lithium carbonate is 20mL:20mL:0.1g.

[0044] In a preferred embodiment, the mass ratio of the multifunctional amine auxiliary agent AMP-95 to polyethylene glycol is 1~2:1.

[0045] In a preferred embodiment, the molecular weight of the polyethylene glycol is 200-600.

[0046] In a preferred embodiment, the anti-agglomeration agent is graphene quantum dots with a particle size of 2-10 nm. Experiments have shown that graphene quantum dots, as an anti-agglomeration agent, can form hydrogen bonds with the surface of single-walled carbon nanotubes due to the presence of hydroxyl and carboxyl functional groups on their surface, further improving dispersion stability and simultaneously enhancing the conductivity of the slurry.

[0047] In a preferred embodiment, the solvent is selected from at least one of water and N-methylpyrrolidone (NMP). In actual operation, deionized water is used. The aqueous system (with deionized water as the solvent) is environmentally friendly and pollution-free, meeting the requirements of green production. The NMP system is suitable for oily electrode materials, and can be flexibly selected according to the downstream application scenario.

[0048] In a preferred embodiment, the solvent is a mixture of deionized water and NMP at a mass ratio of 1 to 3:1. This balances the environmental friendliness of an aqueous system with the compatibility of an oil-based system, making it suitable for a wider range of downstream applications.

[0049] This invention also provides a method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive slurry. The method involves adding a solvent to a container, starting stirring, and then sequentially adding a composite dispersant, a viscosity modifier, and an anti-agglomeration agent. A first stirring is performed to obtain a dispersion medium. Single-walled carbon nanotubes are then added to the dispersion medium, and a second stirring is conducted under ultrasonic assistance to obtain a pre-dispersion of single-walled carbon nanotubes. This pre-dispersion is then ground and dispersed to obtain a ground dispersion. The ground dispersion is then homogenized to obtain a homogeneous dispersion. Finally, the homogeneous dispersion is vacuum degassed and filtered to obtain the final product.

[0050] In a preferred embodiment, the composite dispersant, viscosity modifier, and anti-agglomeration agent are first ground to a particle size ≤10 μm.

[0051] In a preferred embodiment, the single-walled carbon nanotubes are first placed in a vacuum drying oven and dried at 100-120°C for 6-10 hours. Drying removes surface-adsorbed moisture and impurities.

[0052] In the preferred embodiment, the stirring speed is 800~1200 r / min, preferably 1000 r / min; the first stirring time is 30~60 min; the second stirring time is 60~90 min, preferably 75 min; and the ultrasonic power is 200~300 W. Through the first stirring, the composite dispersant, viscosity modifier, and anti-agglomeration agent are completely dissolved in the solvent to obtain a uniform dispersion medium. Then, pretreated purified single-walled carbon nanotubes are slowly added, and stirring continues under ultrasonic assistance to obtain a pre-dispersion of single-walled carbon nanotubes. In this invention, gentle pre-dispersion avoids carbon nanotube breakage, preserves their aspect ratio, and lays the foundation for high conductivity.

[0053] In a further preferred embodiment, during ultrasound-assisted ultrasound, intermittent ultrasound is used, with each ultrasound session lasting 3-10 minutes followed by a 2-4 minute pause. Intermittent ultrasound avoids excessively high temperatures during the ultrasound process, which could lead to carbon nanotube oxidation or dispersant decomposition.

[0054] In a preferred embodiment, the grinding and dispersion process involves transferring the pre-dispersed single-walled carbon nanotube liquid into a three-roll mill. First, the gap between rollers 1 and 2 is set to 280-320 μm, and the gap between rollers 2 and 3 is set to 140-160 μm. The mill is then ground 1-2 times at a speed of 480-520 rpm. Next, the gap between rollers 1 and 2 is adjusted to 140-160 μm, and the gap between rollers 2 and 3 is set to 60-80 μm. The mill is then ground 1-2 times at a speed of 480-520 rpm. Finally, the gap between rollers 1 and 2 is adjusted to 40-60 μm, and the gap between rollers 2 and 3 is set to 15-30 μm. The mill is then ground 1-2 times at a speed of 480-520 rpm.

[0055] In a further preferred embodiment, the rollers of the three-roll mill are made of zirconia ceramic with a runout accuracy of ≤1 μm. To avoid the introduction of metallic impurities, gradient grinding is used in this invention to gradually break down carbon nanotube agglomerates while avoiding damage to the carbon nanotube structure caused by high-intensity grinding.

[0056] In a further preferred embodiment, the total number of grinding operations (first, second, and third) is 4-5 times, with the third grinding performed twice. This ensures that the carbon nanotube aggregates are completely broken down and evenly dispersed.

[0057] In a preferred embodiment, the homogenization and dispersion process involves transferring the grinding dispersion to a high-pressure microfluidic homogenizer, controlling the homogenization pressure at 600-1000 bar, preferably 800 bar, performing homogenization 2-4 times, preferably 3 times, with each homogenization session lasting 10-15 minutes, preferably 12 minutes. Homogenization ensures uniform dispersion of single-walled carbon nanotubes without significant agglomerates; the lower homogenization pressure allows for the opening of the carbon nanotube bundles while avoiding damage to the carbon nanotube length, balancing dispersibility and conductivity, achieving a balance between dispersion effect and carbon nanotube structural integrity, and preventing carbon nanotube breakage due to excessive homogenization.

[0058] In a preferred embodiment, the vacuum degassing process involves transferring the homogeneous dispersion to a vacuum degassing machine and degassing for 30-60 minutes, preferably 45 minutes, at a vacuum level of -30 to -80 kPa, preferably -50 kPa, and a stirring speed of 1500 to 2000 r / min, preferably 1800 r / min. Vacuum degassing removes air bubbles from the system.

[0059] In a preferred embodiment, the filtration process employs a microporous membrane with a diameter of 0.22–0.45 μm. Undispersed large particulate impurities are removed through microporous membrane filtration, resulting in a highly conductive, low-viscosity single-walled carbon nanotube conductive slurry.

[0060] In actual operation, the viscosity, volume resistivity, dispersion stability and metal impurity content of the filtered conductive slurry are tested. After passing the test, it is sealed and packaged under nitrogen protection and stored in a cool and dry place.

[0061] The present invention also provides an application of a highly conductive, low-viscosity single-walled carbon nanotube conductive paste, which is applied to one of the following: power batteries, consumer electronics, flexible electronics, thermal interface materials, and conductive coatings.

[0062] The single-walled carbon nanotube conductive paste of this invention can be widely used in the above-mentioned fields, and is especially suitable for the preparation of positive and negative electrodes of lithium iron phosphate and high-nickel ternary power batteries, as well as the printing of flexible circuit boards and conductive films.

[0063] The specific application method is as follows: the conductive slurry is mixed with the electrode active material and binder in a certain proportion, stirred evenly, and then coated on the surface of the current collector. After drying and rolling, an electrode sheet is obtained. The amount of conductive slurry added is 0.5% to 1.5% of the mass of the electrode active material, which can build a continuous and efficient conductive network. Compared with traditional conductive agents, the amount added is reduced by 30% to 50%, while the internal resistance of the electrode is reduced by 15% to 25%, and the battery cycle life is increased by more than 20%.

[0064] In the field of flexible electronics, the conductive paste can be printed onto the surface of a flexible substrate (such as polyimide or PET) using methods such as screen printing or inkjet printing to prepare flexible conductive circuits. Its low viscosity characteristics are suitable for fine printing, its high conductivity ensures stable transmission of the circuit, and its good flexibility can adapt to the bending and folding of the flexible substrate.

[0065] Beneficial effects

[0066] Compared with the prior art, the present invention has the following significant advantages:

[0067] 1. Achieving a synergistic balance between high conductivity and low viscosity: This invention employs a specific ratio of composite dispersant and viscosity modifier, combined with a stepwise dispersion process of gradient grinding and high-pressure homogenization, to achieve uniform dispersion of single-walled carbon nanotubes and construct a continuous conductive network, resulting in a slurry volume resistivity ≤5×10⁻⁶. -3 With a viscosity of Ω·cm, it can precisely control the viscosity of the slurry, with a room temperature viscosity of ≤2000 mPa·s and excellent fluidity. It solves the core contradiction in existing technologies where conductivity and viscosity are difficult to balance, and is suitable for industrial high-speed coating, fine printing and other processes.

[0068] 2. Excellent dispersion stability and long storage period: Through the synergistic effect of composite dispersants and the steric hindrance effect of anti-agglomeration agents, the agglomeration of single-walled carbon nanotubes is effectively suppressed. The slurry can be sealed and stored at 25°C for more than 6 months without stratification or precipitation. The dispersion stability is far superior to existing products. At the same time, the batch consistency is good, with viscosity fluctuation coefficient ≤ ±3% and conductivity standard deviation ≤ ±5%, meeting the internal control standards of leading power battery customers.

[0069] 3. Low impurity residue and excellent electrochemical performance: High-purity purified single-walled carbon nanotube raw materials are used, with metal impurity residue ≤20 ppm, avoiding side reactions caused by impurities, and suitable for battery systems that are sensitive to impurities, such as high-nickel ternary batteries; at the same time, the composite dispersant and viscosity modifier have no harmful residues and do not affect the electrochemical performance of the slurry, which can improve the cycle stability and safety of the battery.

[0070] 4. High structural integrity and conductivity of carbon nanotubes: The use of mild pre-dispersion and gradient grinding processes avoids the damage to the length and structure of single-walled carbon nanotubes caused by high-intensity dispersion, and retains their high aspect ratio (≥2000:1). It can build a highly efficient conductive network with low addition amount (0.5%~1.5%). Compared with traditional conductive agents, the addition amount is reduced by 30%~50%, which reduces production costs while improving conductivity.

[0071] 5. Flexible formulation and wide compatibility: The solvent can be selected as water-based, oil-based or mixed system according to the application scenario, which can meet the needs of multiple fields such as power batteries, flexible electronics, and conductive coatings; the preparation process can be directly adapted to existing industrial equipment such as three-roll mills and high-pressure micro-jet homogenizers, without the need for new large-scale equipment. The process is simple, easy to operate, and has good repeatability, making it easy to scale up production and in line with the industry's green development trend. Attached Figure Description

[0072] Figure 1 This is a viscosity comparison chart of the conductive paste prepared in Example 1 of the present invention and the pastes of Comparative Example 1 and Comparative Example 2.

[0073] Figure 2 This is a scanning electron microscope (SEM) image of the conductive paste prepared in Example 1 of the present invention. Detailed Implementation

[0074] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention.

[0075] Example 1

[0076] A highly conductive, low-viscosity single-walled carbon nanotube conductive slurry, comprising the following raw materials by mass: 5 parts purified single-walled carbon nanotubes, 2.5 parts composite dispersant (sodium carboxymethyl cellulose to comb-shaped polyamide lithium salt mass ratio 2.8:1), 1.5 parts viscosity modifier (AMP-95 to polyethylene glycol 400 mass ratio 1.5:1), 0.5 parts anti-agglomeration agent (graphene quantum dots, particle size 5~8 nm), and 90.5 parts solvent (deionized water to NMP mass ratio 2:1).

[0077] The purified single-walled carbon nanotubes were prepared by an electric arc method, followed by acid treatment, high-temperature water oxidation, and multi-stage centrifugal purification. The specific preparation process is as follows:

[0078] Step 1: Enhanced acid treatment

[0079] 10 g of single-walled carbon nanotube powder prepared by the electric arc method was placed in a 500 mL round-bottom flask. 250 mL of a 25% hydrochloric acid solution was added (to increase concentration and volume). Then, sodium citrate and EDTA were added, with the amount of sodium citrate added being 5% (12.5 g) of the acid solution mass, and the amount of EDTA added being 5% (12.5 g) of the acid solution mass, with a sodium citrate to EDTA mass ratio of 1:1. The mixture was refluxed and stirred at 110 °C for 12 hours. After treatment, the mixture was centrifuged at 5000 g for 20 minutes, the supernatant was discarded, and the precipitate was collected. The precipitate was washed five times with deionized water, centrifuged at 5000 g for 15 minutes after each wash, and the solid product was collected.

[0080] Step 2: Precise High-Temperature Water Oxidation. The solid product obtained in Step 1 was placed in an oven and dried at 105°C for 4 hours. The dried sample was then placed in a tube furnace with argon as the carrier gas, a water vapor concentration of 20 vol%, and an argon flow rate of 300 mL / min. The temperature was increased to 850°C at a rate of 5°C / min and held at that temperature for 2.0 hours (the water oxidation time was appropriately extended to ensure complete destruction of the carbon-coated metal structure and vaporization of carbon impurities). After treatment, the sample was allowed to cool naturally to room temperature.

[0081] Step 3: Enhanced Multi-Stage Centrifugation. The oxidation product obtained in Step 2 was dispersed in 200 mL of an aqueous solution containing 1.0 wt% sodium dodecyl sulfate (SDS) (increasing the surfactant concentration for more thorough exfoliation), and ultrasonically dispersed for 60 minutes (ultrasonic power 400 W). The dispersion was then subjected to a first-stage centrifugation at 5000 g for 30 minutes, and the lower precipitate was collected (to remove finer, lighter carbon impurities). The lower precipitate was redispersed in 200 mL of an aqueous solution containing 1.0 wt% SDS, ultrasonically dispersed for 30 minutes, and then subjected to a second-stage centrifugation at 30000 g for 90 minutes (significantly increasing the secondary centrifugal force for strong precipitation of metal oxide nanoparticles), and the supernatant was collected.

[0082] Step 4: Post-processing. The supernatant obtained in Step 3 is vacuum filtered to collect the filter cake. The filter cake is dried in a vacuum drying oven at 80℃ and -0.095 MPa for 12 hours to obtain high-purity single-walled carbon nanotube powder.

[0083] The high-purity single-walled carbon nanotube powder obtained above has a metal impurity residue of 18 ppm, a tube diameter of 1.5~1.8 nm, an aspect ratio of 2200:1, a Raman G / D ratio of 95, and a specific surface area of ​​490 m² / g, which is a significant increase compared to 120 m² / g before purification.

[0084] Comb-shaped polyamide lithium salt was prepared as follows: 20 mL of 35 wt% methoxy polyetheramine solution was added to a reaction vessel, and 20 mL of 9.5 wt% 3,3,4,4-benzophenone tetracarboxylic dianhydride solution was added dropwise at 48 °C and 250 r / min. After the addition was complete, 0.1 g of lithium carbonate was added, and the mixture was stirred at 72 °C for 2.8 h. The mixture was then cooled to -10 °C, filtered, and the solvent was removed by rotary evaporation of the filtrate to obtain comb-shaped polyamide lithium salt.

[0085] The preparation method of single-walled carbon nanotube conductive paste is as follows:

[0086] Step 1: Raw material pretreatment: The purified single-walled carbon nanotubes were dried in a vacuum drying oven at 110℃ for 8 h; the composite dispersant, viscosity modifier and anti-agglomeration agent were ground to a particle size ≤10 μm and set aside.

[0087] Step 2: Pre-dispersion: Add 90.5 parts of solvent to the dispersion vessel and stir at 1000 r / min. Then add 2.5 parts of composite dispersant, 1.5 parts of viscosity modifier, and 0.5 parts of anti-agglomeration agent in sequence and stir for 45 min until completely dissolved. Slowly add 5 parts of pretreated single-walled carbon nanotubes and continue stirring for 75 min. At the same time, use 250 W intermittent sonication (sonicate for 5 min, stop for 3 min) to obtain the pre-dispersion liquid.

[0088] Step 3: Gradient grinding and dispersion: Transfer the pre-dispersed liquid to a three-roll mill (zirconia ceramic roller, runout accuracy 1 μm), grind once at 500 rpm with a gap of 300 μm / 150 μm; then grind once at 500 rpm with a gap of 150 μm / 75 μm; finally grind twice at 500 rpm with a gap of 50 μm / 25 μm, for a total of 4 grindings.

[0089] Step 4: High-pressure homogenization and dispersion: Transfer the ground dispersion to a high-pressure microjet homogenizer and homogenize it three times at a pressure of 800 bar, each time for 12 minutes.

[0090] Step 5: Vacuum degassing and filtration: Transfer the homogenized liquid to a vacuum degassing machine and degas for 45 min under a vacuum of -50 kPa and stirring at 1800 r / min; filter with a 0.3 μm microporous membrane to obtain a conductive slurry.

[0091] Performance testing: The conductive paste has a room temperature viscosity of 1650 mPa·s and a volume resistivity of 3.2 × 10⁻⁶. -3 Ω·cm, with 18 ppm of residual metal impurities; after 6 months of sealed storage at 25℃, there was no stratification or precipitation, demonstrating excellent dispersion stability.

[0092] from Figure 1As can be seen, the viscosity of the slurry prepared in Example 1 of the present invention (1650 mPa·s) is significantly lower than that of Comparative Example 1 (5200 mPa·s) and Comparative Example 2 (6050 Pa·s), indicating that the formulation and process of the present invention can effectively reduce viscosity and meet the synergistic requirements of high conductivity and low viscosity.

[0093] Figure 2 The scanning electron microscope (SEM) image of the conductive paste prepared in Example 1 of the present invention shows that the carbon nanotubes are uniformly dispersed and there is no obvious agglomeration.

[0094] When mixed with lithium iron phosphate active material and binder at an addition rate of 1.0%, an electrode sheet was prepared. The internal resistance of the electrode was reduced by 22% compared with that of traditional carbon black conductive agent, and the capacity retention rate was 88% after 1500 battery cycles.

[0095] Example 2

[0096] A highly conductive, low-viscosity single-walled carbon nanotube conductive slurry, comprising the following raw materials by mass: 3 parts purified single-walled carbon nanotubes, 1 part composite dispersant (sodium carboxymethyl cellulose and comb-shaped polyamide lithium salt in a mass ratio of 2.5:1), 0.5 parts viscosity modifier (AMP-95 and polyethylene glycol 200 in a mass ratio of 1:1), 0.1 parts anti-agglomeration agent (nano silica, particle size 30~50 nm), and 95.4 parts solvent (deionized water).

[0097] The purified single-walled carbon nanotubes were prepared by CVD, followed by acid treatment, high-temperature water oxidation, and multi-stage centrifugation purification. The residual metal impurities were 15 ppm, the tube diameter was 1.3~1.6 nm, the aspect ratio was 2000:1, the Raman G / D ratio was 90, and the specific surface area was 500 m² / g (before purification: 115 m² / g). The comb-shaped polyamide lithium salt was prepared by the same method as in Example 1.

[0098] The preparation method of single-walled carbon nanotube conductive paste is as follows:

[0099] Step 1: Raw material pretreatment: Place the purified single-walled carbon nanotubes in a vacuum drying oven at 100℃ and dry for 10 h; grind the composite dispersant, viscosity modifier and anti-agglomeration agent to a particle size ≤10 μm and set aside.

[0100] Step 2: Pre-dispersion: Add 95.4 parts of deionized water to the dispersion vessel and stir at 800 r / min. Then add 1 part of composite dispersant, 0.5 parts of viscosity modifier, and 0.1 parts of anti-agglomeration agent in sequence and stir for 30 min until completely dissolved. Slowly add 3 parts of pretreated single-walled carbon nanotubes and continue stirring for 60 min. At the same time, use 200 W intermittent sonication to obtain a pre-dispersion solution.

[0101] Step 3: Gradient grinding and dispersion: Transfer the pre-dispersed liquid to a three-roll mill and grind it once at 500 rpm with a gap of 300 μm / 150 μm; then grind it once at 500 rpm with a gap of 150 μm / 75 μm; and finally grind it once at 500 rpm with a gap of 50 μm / 25 μm, for a total of 3 grinding cycles.

[0102] Step 4: High-pressure homogenization and dispersion: Transfer the ground dispersion to a high-pressure microfluidic homogenizer and homogenize twice at a pressure of 600 bar, 10 min each time.

[0103] Step 5: Vacuum degassing and filtration: Transfer the homogenized liquid to a vacuum degassing machine and degas for 30 min under a vacuum of -30 kPa and stirring at 1500 r / min; filter with a 0.22 μm microporous membrane to obtain conductive slurry.

[0104] Performance testing: The conductive paste has a room temperature viscosity of 1480 mPa·s and a volume resistivity of 4.8 × 10⁻⁶. -3 Ω·cm, with 15 ppm of residual metal impurities; after 6 months of sealed storage at 25℃, there was no obvious stratification, and the dispersion stability was good; when it was added at a rate of 0.5% to flexible circuit board printing, the circuit conductivity was uniform, and the resistance change rate after 1000 bends was ≤5%.

[0105] Example 3

[0106] A highly conductive, low-viscosity single-walled carbon nanotube conductive slurry, comprising the following raw materials by mass: 8 parts purified single-walled carbon nanotubes, 5 parts composite dispersant (sodium carboxymethyl cellulose and comb-shaped polyamide lithium salt in a mass ratio of 3:1), 3 parts viscosity modifier (AMP-95 and polyethylene glycol 600 in a mass ratio of 2:1), 1 part anti-agglomeration agent (graphene quantum dots, particle size 2~5 nm), and 83 parts solvent (NMP).

[0107] The purified single-walled carbon nanotubes were prepared by electric arc method, followed by acid treatment, high-temperature water oxidation, and multi-stage centrifugation purification. The residual metal impurities were 20 ppm, the tube diameter was 1.7~2.0 nm, the aspect ratio was 2500:1, the Raman G / D ratio was 105, and the specific surface area was 510 m² / g (before purification: 127 m² / g). The comb-shaped polyamide lithium salt was prepared by the same method as in Example 1.

[0108] The preparation method of single-walled carbon nanotube conductive paste is as follows:

[0109] Step 1: Raw material pretreatment: The purified single-walled carbon nanotubes were dried in a vacuum drying oven at 120℃ for 6 h; the composite dispersant, viscosity modifier and anti-agglomeration agent were ground to a particle size ≤10 μm and set aside.

[0110] Step 2: Pre-dispersion: Add 83 parts of NMP to the dispersion vessel and stir at 1200 r / min. Then add 5 parts of composite dispersant, 3 parts of viscosity modifier, and 1 part of anti-agglomeration agent in sequence and stir for 60 min until completely dissolved. Slowly add 8 parts of pretreated single-walled carbon nanotubes and continue stirring for 90 min. At the same time, use 300 W intermittent sonication to obtain the pre-dispersion liquid.

[0111] Step 3: Gradient grinding and dispersion: Transfer the pre-dispersed liquid to a three-roll mill and grind it twice at 500 rpm with a gap of 300 μm / 150 μm; then grind it twice at 500 rpm with a gap of 150 μm / 75 μm; and finally grind it twice at 500 rpm with a gap of 50 μm / 25 μm, for a total of 6 grindings.

[0112] Step 4: High-pressure homogenization and dispersion: Transfer the ground dispersion to a high-pressure microjet homogenizer and homogenize it 4 times at a pressure of 1000 bar, 15 min each time.

[0113] Step 5: Vacuum degassing and filtration: Transfer the homogenized liquid to a vacuum degassing machine and degas for 60 min under a vacuum of -80 kPa and stirring at 2000 r / min; filter with a 0.45 μm microporous membrane to obtain conductive slurry.

[0114] Performance testing: The conductive paste has a room temperature viscosity of 1780 mPa·s and a volume resistivity of 2.5 × 10⁻⁶. -3 Ω·cm, residual metal impurities 20 ppm; after 6 months of sealed storage at 25℃, no stratification or precipitation; when mixed with high-nickel ternary (NCM811) active material at an addition rate of 1.5%, the battery capacity retention rate was 90% after 500 cycles at high temperature (45℃), and the internal resistance growth was less than 8%.

[0115] Comparative Example 1

[0116] A single-walled carbon nanotube conductive paste differs from Example 1 in that it uses sodium carboxymethyl cellulose as a single dispersant, does not add an anti-agglomeration agent, and adopts a one-time grinding process (gap 50 μm / 25 μm, grinding 4 times) without gradient grinding.

[0117] Performance testing: The conductive paste has a room temperature viscosity of 5200 mPa·s and a volume resistivity of 1.2 × 10⁻⁶. -2 The metal impurity residue was 22 ppm in Ω·cm; after being sealed and stored at 25°C for 3 months, it showed stratification and precipitation, indicating poor dispersion stability; the electrode internal resistance was 35% higher than that of Example 1, and the capacity retention rate was 72% after 1500 battery cycles.

[0118] Comparative Example 2

[0119] A conductive paste made of single-walled carbon nanotubes differs from that in Example 1 in that it uses ordinary unpurified single-walled carbon nanotubes (with 60 ppm of residual metal impurities), does not add viscosity modifiers, and the high-pressure homogenization pressure in the preparation process is 1200 bar, with homogenization performed 4 times.

[0120] Performance testing: The conductive paste has a room temperature viscosity of 6050 mPa·s and a volume resistivity of 8.5 × 10⁻⁶. -3 The battery has a high internal resistance of Ω·cm and 60 ppm of residual metal impurities. It exhibits delamination after 4 months of sealed storage at 25°C. The battery has high internal resistance, and its capacity retention rate is only 75% after 1500 cycles. It also shows significant side reactions and poor safety.

Claims

1. A highly conductive, low-viscosity single-walled carbon nanotube conductive paste, characterized in that: The single-walled carbon nanotube conductive paste comprises, by mass parts: 3-8 parts single-walled carbon nanotubes, 1-5 parts composite dispersant, 0.5-3 parts viscosity modifier, 0.1-1 parts anti-agglomeration agent, and 83-95 parts solvent. The composite dispersant is composed of sodium carboxymethyl cellulose and comb-shaped polyamide lithium salt; The viscosity modifier is a compound of multifunctional amine additive AMP-95 and polyethylene glycol; The anti-agglomeration agent is nano-silica and / or graphene quantum dots.

2. The highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 1, characterized in that: The single-walled carbon nanotubes have a residual metal impurity of ≤20 ppm, a tube diameter of 1.3~2.0 nm, an aspect ratio of ≥2000:1, a Raman G / D ratio of ≥90, and a specific surface area of ​​≥100 m² / g.

3. The highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 2, characterized in that: The single-walled carbon nanotubes are obtained by purifying the crude single-walled carbon nanotubes prepared by the arc method or CVD method. The purification process is as follows: the crude single-walled carbon nanotubes are placed in an acid solution containing a complexing agent for acidification treatment, solid-liquid separation is performed, the obtained solid product is placed in a water vapor atmosphere for high-temperature water oxidation treatment to obtain an oxidation product, and then the oxidation product is dispersed in a dispersion medium for multi-stage centrifugal separation treatment. The supernatant is collected and dried to obtain the purified single-walled carbon nanotubes. The acid solution containing the complexing agent is composed of the complexing agent and an acid solution, wherein the acid solution is selected from hydrochloric acid and / or nitric acid; The complexing agent is composed of sodium citrate and EDTA. The amount of sodium citrate added is 0.1%-5% of the mass of the acid solution, and the amount of EDTA added is 0.1%-5% of the mass of the acid solution. The mass ratio of sodium citrate to EDTA is 1-2:1-2. The hydrochloric acid has a mass concentration of 5%-37%, and the nitric acid has a mass concentration of 10%-68%. When the acid solution is selected from hydrochloric acid and nitric acid, the volume ratio of hydrochloric acid to nitric acid is 1-3:1-3; The solid-liquid mass-volume ratio of the single-walled carbon nanotube powder to the acid solution containing the complexing agent is 1g: 50-500mL; The acidification treatment temperature is 60℃-120℃, and the acidification treatment time is 2-24h; The solid-liquid separation method is centrifugation, with a centrifugal force of 1000g-5000g and a centrifugation time of 10-60min; The solid phase obtained from the solid-liquid separation is first pre-dried and then placed in a water vapor atmosphere for high-temperature water oxidation treatment. The temperature of the pre-drying treatment is 80℃-120℃ and the time of the pre-drying treatment is 2-6h. The water vapor atmosphere is formed by heating and evaporating deionized water, which is then introduced into the reactor along with the carrier gas; the water vapor concentration is 5 vol%-30 vol%. The carrier gas is selected from argon or nitrogen, and the flow rate of the carrier gas is 100-500 mL / min; The high-temperature water oxidation treatment is carried out at a temperature of 800-900℃ for a time of 0.5-3 hours. The oxidation product is added to the dispersion medium and dispersed in the dispersion medium by ultrasonic treatment. The ultrasonic power is controlled at 100-800 W and the ultrasonic time is 10-60 min. The dispersion medium contains water; The dispersion medium further comprises a surfactant selected from at least one of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, sodium deoxycholate, or Triton X-100, wherein the concentration of the surfactant in the dispersion medium is 0.1-5 wt%. The multi-stage centrifugal separation process includes at least two stages of centrifugal separation. The centrifugal force of the first stage is 1000g-5000g, and the centrifugal time is 15-60min. After the first centrifugal process is completed, the lower precipitate is collected and then dispersed in a dispersion medium for the second centrifugation. The centrifugal force of the second stage is 10000g-30000g, and the centrifugal time is 30-120min. After the second centrifugation is completed, the supernatant is collected. The drying process is one of vacuum drying, freeze drying, or spray drying. The drying temperature is 60℃-120℃, the drying time is 6-24h, and the vacuum degree is controlled at -0.09~-0.1 MPa during vacuum drying.

4. The highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 1, characterized in that: In the composite dispersant, the mass ratio of sodium carboxymethyl cellulose to comb-shaped polyamide lithium salt is 2.5~3:1; The mass ratio of the multifunctional amine auxiliary agent AMP-95 to polyethylene glycol is 1~2:1; The molecular weight of the polyethylene glycol is 200-600; The anti-agglomeration agent is graphene quantum dots, and the particle size of the graphene quantum dots is 2~10 nm; The solvent is selected from at least one of water and N-methylpyrrolidone.

5. A method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to any one of claims 1-4, characterized in that: The solvent is added to a container and stirred. The composite dispersant, viscosity modifier, and anti-agglomeration agent are added in sequence. The dispersion medium is obtained by stirring for the first time. Single-walled carbon nanotubes are added to the dispersion medium and stirred for the second time under ultrasonic assistance to obtain a pre-dispersion of single-walled carbon nanotubes. The pre-dispersion of single-walled carbon nanotubes is then ground and dispersed to obtain a ground dispersion. The ground dispersion is then homogenized to obtain a homogeneous dispersion. Finally, the homogeneous dispersion is degassed under vacuum and filtered to obtain the final product.

6. The method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 5, characterized in that: The composite dispersant, viscosity modifier, and anti-agglomeration agent are first ground to a particle size ≤10 μm; The single-walled carbon nanotubes were first placed in a vacuum drying oven and dried at 100~120℃ for 6~10 h.

7. The method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 5, characterized in that: The stirring speed is 800~1200 r / min, the first stirring time is 30~60 min, the second stirring time is 60~90 min, and the ultrasonic-assisted power is 200~300 W; When using ultrasound assistance, intermittent ultrasound is employed, with each ultrasound session lasting 3-10 minutes followed by a 2-4 minute pause.

8. The method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 5, characterized in that: The grinding and dispersion process is as follows: the pre-dispersed liquid of single-walled carbon nanotubes is transferred to a three-roll mill. First, the gap between roller 1 and roller 2 is set to 280-310 μm, and the gap between roller 2 and roller 3 is set to 140-160 μm. The first grinding is performed 1-2 times at a speed of 480-520 rpm. Then, the gap between roller 1 and roller 2 is adjusted to 140-160 μm, and the gap between roller 2 and roller 3 is set to 60-80 μm. The second grinding is performed 1-2 times at a speed of 480-520 rpm. Finally, the gap between roller 1 and roller 2 is adjusted to 45-55 μm, and the gap between roller 2 and roller 3 is set to 20-30 μm. The third grinding is performed 1-2 times at a speed of 480-520 rpm. The homogenization and dispersion process is as follows: the grinding dispersion is transferred to a high-pressure micro-jet homogenizer, the homogenization pressure is controlled at 600~1000 bar, the homogenization is performed 2~4 times, and the homogenization time is 10~15 min each time.

9. The method for preparing a highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to claim 5, characterized in that: The vacuum degassing process is as follows: the homogeneous dispersion is transferred to a vacuum degassing machine and degassed for 30 to 60 minutes at a vacuum degree of -30 to -80 kPa and a stirring speed of 1500 to 2000 r / min. The filtration process uses a microporous membrane with a diameter of 0.22~0.45 μm.

10. The application of the highly conductive, low-viscosity single-walled carbon nanotube conductive paste according to any one of claims 1-4, characterized in that: The single-walled carbon nanotube conductive paste is applied to one of the following: power batteries, consumer electronics, flexible electronics, thermal interface materials, and conductive coatings.

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