阅读说明：本技术 一种易分散碳纳米管粉末的制备方法及碳纳米管粉末 (Preparation method of easily-dispersible carbon nanotube powder and carbon nanotube powder ) 是由 谢宝东 周叶 毛鸥 张美杰 郑涛 于 2018-11-12 设计创作，主要内容包括：本发明公开一种碳纳米管导电剂的制备方法,具体涉及一种易分散碳纳米管粉末的制备方法及由该方法制得的碳纳米管粉末,该制备方法包括以下步骤：通过珠磨制备含碳纳米管的分散浆料；然后对分散浆料进行干燥得到固体粉末,其得到的碳纳米管粉末中的碳纳米管的含量高,分散效果好,其制备工艺简单。(The invention discloses a preparation method of a carbon nano tube conductive agent, and particularly relates to a preparation method of easily-dispersed carbon nano tube powder and the carbon nano tube powder prepared by the method, wherein the preparation method comprises the following steps: preparing a dispersion slurry containing carbon nanotubes by bead milling; and then drying the dispersion slurry to obtain solid powder, wherein the obtained carbon nanotube powder has high carbon nanotube content, good dispersion effect and simple preparation process.)

1. A preparation method of easily-dispersed carbon nanotube powder is characterized by comprising the following steps: the method comprises the following steps:

(1) preparing a dispersion slurry containing carbon nanotubes by bead milling;

(2) and (2) drying the dispersed slurry prepared in the step (1) to obtain solid powder.

2. The method for preparing the readily dispersible carbon nanotube powder of claim 1, wherein: and (2) sanding the zirconium beads with the diameter of 0.3-10mm in the bead grinding process in the step (1).

3. The method for preparing the readily dispersible carbon nanotube powder of claim 1, wherein: the linear speed of the bead mill is 10-13 m/s.

4. The method for preparing the readily dispersible carbon nanotube powder of claim 1, wherein: the drying method in the step (2) is one or combination of low-temperature freeze drying, spray drying, fluidized bed drying, vacuum drying and rake drying.

5. The method for preparing the readily dispersible carbon nanotube powder of claim 1, wherein: the carbon nano tube conductive slurry in the step (1) comprises a conductive agent, a dispersing agent and a solvent, wherein the mass content of the solvent is 92.0-99.0%, the mass content of the dispersing agent is 0-2.0%, and the mass content of the conductive agent is 1.0-6.0%.

6. The method for preparing the readily dispersible carbon nanotube powder of claim 1, wherein: the conductive agent is a carbon nano tube and comprises one or a mixture of a single-wall carbon nano tube, a double-wall carbon nano tube and a multi-wall carbon nano tube.

7. The method for preparing the readily dispersible carbon nanotube powder of claim 5, wherein: the dispersing agent is one or a mixture of more of polyvinylpyrrolidone, polyacrylamide, polycarboxylic acid, polyacrylic acid, polycarboxylate, polyacrylate, polystyrene sulfonate, polyvinyl alcohol, ethoxylated alcohol and montan wax.

8. The method for preparing the readily dispersible carbon nanotube powder of claim 5, wherein: the solvent is one or a mixture of water, methanol, ethanol, n-propanol, isopropanol, acetone, NMP, butanol, butanediol, pentane, n-hexane, cyclohexane, trichloroethane, carbon tetrachloride, ethyl acetate, methyl ethyl ketone, dimethylformamide, dimethylacetamide, benzene and xylene.

9. A carbon nanotube powder produced by the production method according to any one of claims 1 to 8, characterized in that: the carbon nano tube powder contains 75-100% of carbon nano tubes by mass percent, and can be directly used for anode and cathode slurry of lithium batteries or directly replace conductive carbon black in the fields of lead-acid batteries, conductive plastics and coatings.

Technical Field

The invention relates to a preparation method of a carbon nano tube conductive agent, in particular to a preparation method of easily-dispersed carbon nano tube powder and the carbon nano tube powder.

Background

The carbon nano tube has very good conductive performance and extremely high length-diameter ratio, and the carbon nano tube is added into an electrode material of the lithium ion battery to effectively form a conductive network, so that the conductive performance of the electrode is improved, and the lithium ion battery has excellent performance, particularly shows large battery capacity and long cycle life, and is suitable for high-end-number batteries and new energy automobile batteries.

However, the carbon nanotubes are extremely difficult to disperse, and the produced carbon nanotubes can only be dispersed in solvent forming slurry for sale in the prior art, the content of the carbon nanotubes in the carbon nanotube conductive slurry in the mode is only 3% -8%, the content of the solvent is over 90%, and the application range and the field of the carbon nanotubes are limited. More than 90% of the solvent also causes difficulties in transportation and increases in the cost of use for the customer.

Chinese patent application CN102275899 discloses a method for preparing amphoteric carbon nanotube dispersion powder, which comprises dispersing carbon nanotubes in water by using surfactant under the action of ultrasound and stirring to obtain uniform and stable dispersion liquid, and then repeatedly freeze-drying the dispersion liquid to obtain carbon nanotube powder, wherein the carbon nanotube powder can be rapidly and uniformly dispersed in water and most organic solvents, so that transportation and storage are more convenient, transportation and storage cost of the carbon nanotubes is reduced, and the content of the carbon nanotubes in the carbon nanotube powder is increased, but the method has low efficiency, the content of the carbon nanotubes in the carbon nanotube dispersion liquid obtained by ultrasound is only 0.1%, and the content of the carbon nanotubes in the carbon nanotube powder obtained finally is 60-70% at most, which cannot be increased any more.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of easily-dispersed carbon nanotube powder, the obtained carbon nanotube powder has high carbon nanotube content, good dispersion effect and simple preparation process.

The invention realizes the aim through the following technical scheme:

a preparation method of easily-dispersed carbon nano powder comprises the following steps:

(1) preparing dispersion slurry containing carbon nanotubes by bead milling;

(2) and (2) drying the dispersed slurry prepared in the step (1) to obtain solid powder.

The slurry is prepared from the powder containing the carbon nano tubes by adopting a bead mill mode, the dispersion effect of the carbon nano tubes in the slurry can be effectively improved, the powder is formed after the final slurry is dried and is stored, transported and has better safety, and compared with the traditional mode of storing and transporting the carbon nano tubes by adopting a solvent form, the slurry has the advantages of lower storage and transportation cost and better safety.

The method for preparing the dispersion slurry with high carbon nanotube content in the step (1) is bead milling, and comprises one or two of stirring milling and sand milling.

In the bead milling process in the step (1), the diameter of the zirconium beads is 0.3-10mm, and specifically, when stirring milling equipment is adopted, the diameter of the zirconium beads is 5-10 mm; when using a sanding apparatus, the zirconium beads have a diameter of 0.3-1.2mm, both of which are known from the prior art and will not be described in detail here.

Furthermore, the linear velocity of the bead mill is 10-13m/s, the bead mill mode is applied to the technical field of carbon nano tubes, and finally the carbon nano tubes can be prepared into powder for storage and sale, so that the transportation and storage cost is greatly reduced.

The drying method in the step (2) is one or combination of low-temperature freeze drying, spray drying, fluidized bed drying, vacuum drying and rake drying.

The carbon nano tube conductive slurry in the step (1) comprises a conductive agent, a dispersing agent and a solvent, wherein the mass content of the solvent is 92-99%, the mass content of the dispersing agent is 0-2%, and the mass content of the conductive agent is 1.0-6.0%.

The proportion can improve the content of the carbon nano tube in the finally obtained carbon nano tube powder, and the dispersion effect is good.

The conductive agent is carbon nano-tube (CNT), including one or a mixture of single-wall carbon nano-tube, double-wall carbon nano-tube and multi-wall carbon nano-tube.

The dispersing agent is one or a mixture of more of polyvinylpyrrolidone (PVP), polyacrylamide, polycarboxylic acid, polyacrylic acid, polycarboxylate, polyacrylate, polystyrene sulfonate, polyvinyl alcohol, ethoxylated alcohol and montan wax.

The solvent is one or a mixture of more of water, methanol, ethanol, N-propanol, isopropanol, acetone, N-methylpyrrolidone (NMP), butanol, butanediol, pentane, N-hexane, cyclohexane, trichloroethane, carbon tetrachloride, ethyl acetate, methyl ethyl ketone, dimethylformamide, dimethylacetamide, benzene and xylene.

The carbon nanotube powder prepared by the preparation method contains 75-100% of carbon nanotubes and 0-25% of dispersant by mass percent, and can be directly used for anode and cathode slurry of lithium batteries or directly replace conductive carbon black powder in the fields of lead-acid batteries, conductive plastics and coatings.

The invention has the beneficial effects that:

the carbon nanotube powder prepared by the preparation method has high carbon nanotube content and good dispersibility, can be stored, transported and sold in a powder state, and has lower storage and transportation cost and better safety performance compared with the traditional carbon nanotube powder in a slurry state which needs to adopt a large amount of solvent for storage and transportation. When the conductive paste is used, the solvent is directly added to prepare the paste which can be coated on the pole piece, and the obtained pole piece has low resistivity and good conductivity. The easily-dispersible carbon nanotube powder can be directly used by lithium ion battery customers, and can replace traditional conductive carbon black to be directly used by customers in other fields such as lead-acid batteries, conductive plastics, conductive coatings and the like without additional dispersion. Compared with the conductive paste, the powder product is convenient for overseas transportation, and the cost of overseas customers is greatly reduced.

Drawings

Fig. 1 is an SEM image of the carbon nanotube powder prepared in example 1.

Fig. 2 is an SEM image of the carbon nanotube powder prepared in example 2.

Fig. 3 is an SEM image of the carbon nanotube powder prepared in example 3.

Fig. 4 is an SEM image of the carbon nanotube powder prepared in example 4.

Fig. 5 is an SEM image of the carbon nanotube powder prepared in example 5.

Fig. 6 is an SEM image of the carbon nanotube powder prepared in example 6.

Fig. 7 is an SEM image of the carbon nanotube powder prepared in example 7.

Fig. 8 is an SEM image of the carbon nanotube powder prepared in example 8.

Fig. 9 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 1.

Fig. 10 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 2.

Fig. 11 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 3.

FIG. 12 is an SEM electron micrograph of a pole piece made from a prior art FT9110 carbon nanotube slurry.

Fig. 13 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 4.

FIG. 14 is an SEM micrograph of a pole piece made using another FT9110 carbon nanotube slurry on the market.

Fig. 15 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 5.

Fig. 16 is an SEM electron micrograph of a pole piece made of the carbon nanotube powder prepared in example 5.

FIG. 17 is an SEM electron micrograph of a pole piece made from a conventional commercially available FT7010 carbon nanotube slurry.

Fig. 18 is an SEM electron micrograph of a carbon nanotube powder prepared using the preparation method of comparative example 1.

Detailed Description

The physical properties of the carbon nanotubes FT9110, FT7010, and FT7000 used in this example were as follows: FT9110 is prepared from high-purity carbon tube with purity of 99.8% or more, Fe of 50ppm or less, average diameter of 10-15nm, length of less than 10um, 160-230 m²/g。

FT7010 is high purity carbon tube with purity not less than 99.8%, Fe not more than 80ppm, and average diameter of 711nm below zero, 5-20um in length and 200-280 m in length²/g。

FT7000 is a multi-walled unpurified carbon tube, the purity is not less than 90.0%, the average diameter is 7-11nm, the length is 5-20um, and 200-280 m²/g。

The sanding equipment used is also prior art.