WO2020220566A1 - Method for preparing polyionic liquid-based thermoelectric material - Google Patents

Abstract

A method for preparing a polyionic liquid-based thermoelectric material, comprising: mixing and grinding polyionic liquid and macromolecular sulfonic acid to obtain sulfonic acid doped polyionic liquid; dissolving the sulfonic acid doped polyionic liquid in a phenol solvent and stirring the mixed solution to obtain a polyionic liquid solution; and adding a nanocarbon material to the polyionic liquid solution, stirring and drying the mixture to obtain the polyionic liquid-based thermoelectric material. The method improves the ordering degree of the molecular chains of the polyionic liquid by means of the interaction of the phenol solvent and the polyionic liquid molecules, and then, by combination with the nanocarbon material, achieves the ordered accumulation of the polyionic liquid molecules by means of the induction of the carbon nanotubes, and further enhances the ordering degree of molecular chains of the polyionic liquid to obtain the high-performance polyionic liquid-based thermoelectric material.

Description

Preparation method of polyionic liquid-based thermoelectric material Technical field

The invention relates to the field of organic thermoelectric materials, in particular to a method for preparing polyionic liquid-based thermoelectric materials.

Background technique

With the rapid economic development, people’s demand for energy is increasing. Thermoelectric materials are functional materials that use the movement of carriers inside a solid to directly realize the mutual conversion between heat and electric energy. It has simple structure, small size and weight. It has the advantages of light weight, no transmission parts, no noise, zero emission, easy control, long service life and high reliability. It is considered to be one of the most promising new energy materials. The evaluation index of the material's thermoelectric performance is the dimensionless thermoelectric figure of merit ZT=S ² σT/κ, where S, σ, T and κ are the Seebeck coefficient, electrical conductivity, temperature and thermal conductivity of the material, respectively. For traditional inorganic semiconductor thermoelectric materials (such as Bi ₂ Te ₃ , PbTe, etc.), raw materials are limited, expensive, difficult to process, toxic, and severely pollute the environment, which seriously hinders their industrial application.

In recent years, the research of organic conductive polymer materials has made important progress. Compared with inorganic thermoelectric materials, organic thermoelectric materials are not only rich in resources, low in price, easy to synthesize, easy to process, light in weight, and low in thermal conductivity (usually 0.1- 0.5W·m ^-1 ·K ^-1 or W/(m·K)), which has important application prospects. However, the organic thermoelectric materials in the prior art have a low degree of order in the arrangement of polyionic liquids, resulting in the conductivity of organic thermoelectric materials being much lower than that of inorganic materials, resulting in the fact that the thermoelectricity of organic thermoelectric materials is still lower than that of inorganic materials. .

Therefore, the existing technology needs to be improved and developed.

Summary of the invention

The technical problem to be solved by the present invention is to provide a method for preparing polyionic liquid-based thermoelectric materials in view of the above-mentioned defects of the prior art, which aims to solve the problem of the lack of order in the prior art of organic thermoelectric materials due to the arrangement of polyionic liquids. High, resulting in the electrical conductivity of organic thermoelectric materials being much lower than that of inorganic materials, causing the problem that the thermoelectric properties of organic thermoelectric materials are still lower than that of inorganic materials.

The technical solution adopted by the present invention to solve the technical problem is: a preparation method of polyionic liquid-based thermoelectric material, the specific steps are as follows:

A. Mix and grind the polyionic liquid with macromolecular sulfonic acid to obtain a polyionic liquid doped with sulfonic acid;

B. Dissolve the polyionic liquid doped with sulfonic acid in a phenol solvent and stir to obtain a polyionic liquid solution;

C. Add the nano carbon material to the polyionic liquid solution, stir and dry, to obtain a polyionic liquid-based thermoelectric material.

The preparation method of the polyionic liquid-based thermoelectric material, wherein, in step A, the structural formula of the polyionic liquid is:

among them,

The preparation method of the polyionic liquid-based thermoelectric material, wherein in step A, the grinding time is 0.5-5h, and the molar ratio of the polyionic liquid to the macromolecular sulfonic acid is 1.5-2.0:1.

The preparation method of the polyionic liquid-based thermoelectric material, wherein, in step A, the macromolecular sulfonic acid is camphorsulfonic acid, dodecylbenzenesulfonic acid, p-toluenesulfonic acid and/or dinonylnaphthalenesulfonic acid acid.

The preparation method of the polyionic liquid-based thermoelectric material, wherein, in step B, the phenol solvent is m-cresol, p-cresol, ethyl phenol, 2-chlorophenol and/or 2-fluorophenol.

The preparation method of the polyionic liquid-based thermoelectric material, wherein, in step B, the stirring time is 1-24h, the stirring speed is 100-1000rpm, and the mass concentration of the polyionic liquid solution is 1wt %～l0wt%.

In the preparation method of the polyionic liquid-based thermoelectric material, in step C, the nano-carbon material is carbon nanotube, graphene, carbon fiber or C60.

In the preparation method of the polyionic liquid-based thermoelectric material, in step C, the mass concentration of the nano-carbon material in the polyionic liquid solution is 1 wt% to 90 wt%.

The preparation method of the polyionic liquid-based thermoelectric material, wherein, in step C, the stirring time is 0.5-12h, the stirring speed is 100-1000 rpm; the drying conditions are: 20°C-80 Vacuum drying at ℃ for 24-120h.

A polyionic liquid-based thermoelectric material, which is prepared by the method for preparing a polyionic liquid-based thermoelectric material as described above.

Beneficial effects: The present invention dissolves the polyionic liquid doped with sulfonic acid in the phenol solvent, and uses the chemical interaction force between the phenol solvent and the polyionic liquid molecule to influence the conformation of the polyionic liquid molecular chain, and initially improves the molecular chain of the polyionic liquid The degree of order of arrangement; through the combination of polyionic liquid and nano-carbon material, the ordered structure of nano-carbon material and the conjugation effect between nano-carbon and polyionic liquid molecules induce the orderly growth of polyionic liquid molecules to further improve The order degree of ionic liquid molecular chain arrangement, under the synergistic induction of phenol solvent and nano-carbon material, a highly ordered nano-carbon/polyionic liquid composite material with polyionic liquid molecular chain is obtained, thereby reducing the internal and inter-chain The defect of the π-π conjugation effect formed by the disorderly arrangement of the molecular chains provides a high-performance polyionic liquid-based thermoelectric material. The preparation method of the present invention has simple operation, low cost, and low requirements for the conditions required by the preparation method and the professional technical requirements of experimental operators.

Description of the drawings

Fig. 1 is a flow chart of a preferred embodiment of the preparation method of the polyionic liquid-based thermoelectric material of the present invention.

Detailed ways

The present invention provides a method for preparing a polyionic liquid-based thermoelectric material. In order to make the objectives, technical solutions and advantages of the present invention clearer and clearer, the present invention will be described in further detail below. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention.

Specifically, please refer to FIG. 1. FIG. 1 is a flowchart of a preferred embodiment of the preparation method of a polyionic liquid-based thermoelectric material of the present invention, as shown in the figure, which includes the steps:

S1. Mix and grind the polyionic liquid and the macromolecular sulfonic acid to obtain a polyionic liquid doped with sulfonic acid.

As a specific embodiment of the present invention, the structural formula of the polyionic liquid in this example is

among them,

The structure of polyionic liquids contains asymmetric cations and anions. It not only has the high ionic conductivity, thermal stability, tunable solution properties and chemical stability of ionic liquids, but also has some polymer properties (processable , Physical and mechanical properties). Compared with ionic liquids, polyionic liquids have enhanced mechanical stability, improved processing performance, durability and spatial controllability, which promote polyionic liquids to become a new type of functional material. Preferably, the polyionic liquid in this embodiment consists of pyridine cation and tetraimidazole boron anion.

Further, the macromolecular sulfonic acid in this embodiment is camphor sulfonic acid, dodecyl benzene sulfonic acid, p-toluene sulfonic acid and/or dinonyl naphthalene sulfonic acid. The small-molecular inorganic acid will slowly release and corrode other devices during use. At the same time, the conductivity will decrease, and the reaction will be more violent in the high-temperature and humid environment. Therefore, the macro-molecular sulfonic acid is selected in this embodiment. During the mixing and grinding of polymer ions and macromolecular sulfonic acid, the polymer chain swells and the chain rotates to reduce the binding defects of the π bond on the skeleton, which enhances the delocalization effect of the polymer chain and enhances the conductivity. At the same time, the negatively charged sulfonic acid ions on the macromolecular sulfonic acid and the anions on the polyionic liquid undergo a complex decomposition reaction to replace the anions of the polyionic liquid with sulfonate ions, which enhances the hydrophobicity and aromaticity of the polyionic liquid , So that the polyionic liquid can be dissolved in organic solvents such as chloroform and phenols. Preferably, the molar ratio of the polyionic liquid to the macromolecular sulfonic acid in this embodiment is 1.5 to 2.0:1, and the mixed grinding is to use a grinder to grind for 0.5 to 5 hours, so that the polyionic liquid and the macromolecular sulfonic acid can be fully mixed.

S2. Dissolve the polyionic liquid doped with sulfonic acid in a phenol solvent and stir to obtain a polyionic liquid solution.

Specifically, phenolic compounds are compounds produced by replacing the hydrogen atoms on the benzene ring in aromatic hydrocarbons with hydroxyl groups, and are hydroxyl-containing derivatives of aromatic hydrocarbons, which can be divided into monohydric phenols and polyhydric phenols according to the number of hydroxyl groups contained in their molecules. In this embodiment, the polyionic liquid and the macromolecular sulfonic acid are mixed and ground to enhance the hydrophobicity and aromaticity of the polyionic liquid, thereby increasing the solubility of the polyionic liquid in the phenol solvent. The sulfonic acid-doped polyionic liquid is further dissolved in a phenol solvent, and the hydroxyl group on the phenol solvent forms a hydrogen bond with the polyionic liquid or the π bond on the phenol solvent forms a π-π co-existence with the π bond on the polyionic liquid. Conjugation uses the chemical interaction force between the phenol solvent and the polyionic liquid molecules to affect the conformation of the polyionic liquid molecular chain, and initially improves the order of the polyionic liquid chain arrangement. The phenol solvent is m-methylphenol, p-methylphenol, ethylphenol, 2-chlorophenol and/or 2-fluorophenol. Preferably, m-methylphenol is selected as the phenol solvent in this embodiment, and sulfonic acid is mixed After the heteropoly ionic liquid is dissolved in m-cresol, the hydroxyl and benzene ring on the m-cresol form hydrogen bonds and π-π conjugation between the m-cresol and the polyionic liquid. The intermolecular between m-cresol and polyionic liquid The chemical interaction force increases the order of the molecular chain arrangement of the polyionic liquid, thereby improving the thermoelectric properties of the polyionic liquid.

Further, in this embodiment, after the sulfonic acid-doped polyionic liquid is dissolved in a phenol solvent, it is stirred at room temperature for 1-24 hours at a stirring speed of 100-1000 rpm until the sulfonic acid-doped polyionic liquid and the phenol solvent are completely Mix well. According to the actual melting point of the phenol solvent, you can choose to stir at room temperature or heat to stir. For example, the melting point of p-methylphenol is 32°C to 34°C. When p-methylphenol is selected as the solvent, you can choose to stir at 40°C. Preferably, the stirring time in this embodiment is 8 hours, and the stirring speed is 500 rpm. The concentration of the obtained polyionic liquid solution is 1wt% to 10wt%, so that the sulfonic acid-doped polyionic liquid can be completely dispersed in the phenol solvent, so that the polyionic liquid and the nanocarbon material can be combined in the phenol solvent in the subsequent steps .

S3. Adding the nano carbon material into the polyionic liquid solution, stirring and drying, to obtain a polyionic liquid-based thermoelectric material.

Specifically, carbon nanomaterials have unique structures and excellent physical properties, such as ordered structures with large specific surface area and high aspect ratio, light weight, good thermal conductivity, metal or semiconductor properties, good electrical conductivity, and outstanding mechanical properties. Strength etc. Combining polyionic liquid with carbon nanomaterials and introducing carbon nanomaterials into polyionic liquid can comprehensively utilize its superior characteristics. The carbon nano material is carbon nanotube, graphene, carbon fiber or C60. Preferably, single-walled carbon nanotube is selected in this embodiment. The tetraimidazole boron anion in the polyionic liquid has a strong affinity for the π electrons on the surface of the single-walled carbon nanotubes, and can form a tetraimidazole boron anion gel with the single-walled carbon nanotubes, which not only improves the conductivity of the polyionic liquid, And it solves the problems of polyionic liquid material with high dielectric constant and easy to be charged with static electricity. At the same time, the surface of carbon nanomaterials is chemically inert, making it difficult to control the surface. Through the selection of polyionic liquids, different functionalized polyionic liquid surface carbon skeletons can be obtained. The carbon surface has a surface confinement effect on polyionic liquids. The arrangement guiding effect further improves the order degree of the molecular chain arrangement of the polyionic liquid, thereby improving the thermoelectric performance of the polyionic liquid.

Furthermore, the higher the mass percentage of the nanocarbon material in the polyionic liquid solution, the better the thermoelectric performance of the polyionic liquid material, but at the same time the nanocarbon material is more likely to agglomerate in the polymer due to its own nanosize effect. The mass percentage of the nanocarbon material added in the embodiment in the polyionic liquid solution is 1 wt% to 90 wt%. After the carbon nano material is added to the polyionic liquid solution, in order to make the carbon nano material and the polyionic liquid fully contact and mix the molecules, the mixed solution of the carbon nano material and the polyionic liquid is stirred at room temperature for 0.5-12 hours, and the stirring speed is 100 ~1000rmp. Preferably, the stirring time in this embodiment is 2 h, and the stirring speed is 500 rpm.

Further, in order to obtain a polyionic liquid-based thin-film thermoelectric material or a bulk thermoelectric material, in this embodiment, the nanocarbon material is added to the polyionic liquid solution and stirred for a period of time, and then a certain amount of the mixed solution is poured on the glass substrate. Vacuum drying at 20°C to 80°C for 24 to 120 hours to remove the solvent to obtain a polyionic liquid-based film thermoelectric material. Or take a certain amount of mixed solution and pour it on the glass substrate, first dry it naturally at room temperature in a fume hood to remove most of the solvent, and then put it in a vacuum drying oven at 20℃～80℃ for 24～120h to completely remove the solvent , To obtain polyionic liquid-based bulk thermoelectric material.

The present invention also provides a polyionic liquid-based thermoelectric material, which is prepared by the above-mentioned preparation method.

The preparation method of the polyionic liquid-based thermoelectric material of the present invention initially improves the order of the molecular chains of the polyionic liquid through the interaction of the phenol solvent and the polyionic liquid molecule, and then combines with the nano-carbon material to induce polymerization by carbon nanotubes. The orderly accumulation of ionic liquid molecules further enhances the order of arrangement of polyionic liquid molecular chains to obtain high-performance polyionic liquid-based thermoelectric materials.

The present invention will be further explained below through specific embodiments.

Example 1

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

The prepared camphorsulfonic acid-doped polyionic liquid powder was added to 6 mL of m-cresol, and stirred at a stirring speed of 500 rpm at room temperature for 8 hours to obtain a polyionic liquid solution. 0.03 mL of the polyionic liquid solution was extracted and poured onto a glass substrate with an area of 20×20 mm ² , and the solvent was removed by vacuum drying at 60° C. for 48 hours to obtain a polyionic liquid film. The electrical conductivity σ of the prepared polyionic liquid film is 292S/cm, the Seebeck coefficient S is 20μV/K, and the thermal conductivity κ is 0.22W/( m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid film at 300K is 0.016.

Example 2

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

The prepared camphorsulfonic acid-doped polyionic liquid powder was added to 6 mL of m-cresol, and stirred at a stirring speed of 500 rpm at room temperature for 8 hours to obtain a polyionic liquid solution. Single-walled carbon nanotubes with a mass of 0.372g were added to the polyionic liquid solution, stirred at room temperature at 500rpm for 2h, and 0.03mL of the solution was also extracted and poured onto a glass substrate with an area of 20×20mm ² . The solvent was removed by vacuum drying at 60°C for 48 hours to obtain a carbon nanotube/polyionic liquid composite film with a carbon nanotube mass percentage of 64%. Using a conductivity meter, a Seebeck measuring system and a thermal conductivity meter, the conductivity σ of the prepared polyionic liquid film is 339S/cm, the Seebeck coefficient S is 33μV/K, and the thermal conductivity κ is 0.34W/( m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid film at 300K is 0.032.

Example 3

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

The prepared camphorsulfonic acid-doped polyionic liquid powder was added to 6 mL of m-cresol, and stirred at a stirring speed of 500 rpm at room temperature for 8 hours to obtain a polyionic liquid solution. Single-walled carbon nanotubes with a mass of 2.409g were added to the polyionic liquid solution, stirred at room temperature for 2 hours at a stirring speed of 500rpm, and 0.03mL of the solution was also extracted and poured onto a glass substrate with an area of 20×20mm ² . The solvent was removed by vacuum drying at 60°C for 48 hours to obtain a carbon nanotube/polyionic liquid composite film with a carbon nanotube mass percentage of 89%. Using a conductivity meter, a Seebeck measurement system and a thermal conductivity meter, the conductivity meter σ of the prepared polyionic liquid film is 341S/cm, the Seebeck measurement system S is 34 μV/K, and the thermal conductivity κ is 0.39W. /(m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid film at 300K is 0.030.

Example 4

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

Weigh 0.21 g of camphorsulfonic acid-doped polyionic liquid powder and add it to 3 mL of m-cresol solvent, and stir for 8 hours at a stirring speed of 500 rpm at room temperature to obtain a polyionic liquid solution. Take 1 mL of the polyionic solution, dry it naturally at room temperature in a fume hood to remove most of the solvent, and then place it in a vacuum drying oven at 60°C for 72 hours to obtain a polyionic liquid block treated with m-cresol solvent. Using a conductivity meter, a Seebeck measuring system and a thermal conductivity meter, the conductivity σ of the prepared polyionic liquid block is 70S/cm, the Seebeck coefficient S is 15μV/K, and the thermal conductivity κ is 0.3W/ (m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid block at 300K is 0.002.

Example 5

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

Weigh 0.21 g of camphorsulfonic acid-doped polyionic liquid powder and add it to 3 mL of m-cresol solvent, and stir for 8 hours at a stirring speed of 500 rpm at room temperature to obtain a polyionic liquid solution. Single-walled carbon nanotubes with a mass of 0.372g were added to the above polyionic liquid solution, and stirred at room temperature at 500 rpm for 1 hour; then 1 mL of the polyionic liquid solution was taken and dried first in a fume hood at room temperature to remove Most of the solvents are then put into a vacuum drying cabinet and dried at 60° C. for 72 hours to obtain a single-walled carbon nanotube/polyionic liquid composite block with a carbon nanotube mass percentage of 64%. Using a conductivity meter, a Seebeck measuring system and a thermal conductivity meter, the conductivity σ of the prepared polyionic liquid block is 90S/cm, the Seebeck coefficient S is 35μV/K, and the thermal conductivity κ is 0.6W/ (m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid block at 300K is 0.006.

Example 6

Weigh 0.093g of polyionic liquid powder, add camphorsulfonic acid in a ratio of 2:1 molar ratio of polyionic liquid to camphorsulfonic acid, mix and grind it with a grinder for 2 hours to obtain camphorsulfonic acid doped polyionic liquid powder.

Weigh 0.21 g of camphorsulfonic acid-doped polyionic liquid powder and add it to 3 mL of m-cresol solvent, and stir for 8 hours at a stirring speed of 500 rpm at room temperature to obtain a polyionic liquid solution. Single-walled carbon nanotubes with a mass of 1.767g were added to the above polyionic liquid solution (the content of polyionic liquid was 0.093g), and the stirring speed was 500rpm at room temperature for 1 hour; then 1mL of the polyionic liquid solution was taken first Dry naturally at room temperature in a fume hood to remove most of the solvent, and then put it in a vacuum drying oven at 60°C for 72 hours to obtain a single-walled carbon nanotube/polyionic liquid with a carbon nanotube content of 89% by mass Composite block. The conductivity σ of the prepared polyionic liquid block is 390S/cm, the Seebeck coefficient S is 57μV/K, and the thermal conductivity κ is 0.7W/ by using the conductivity meter, the Seebeck measuring system and the thermal conductivity meter. (m·K), according to the formula ZT=S ² σT/κ, the ZT value of the prepared polyionic liquid block at 300K is 0.054.

The thermoelectric performance index comparison table of the polyionic liquid-based thermoelectric materials prepared in Examples 1-6 is shown in Table 1:

Table 1 Comparison of thermoelectric performance indicators of materials prepared in Examples 1-6

Using a conductivity meter, a Seebeck measuring system and a thermal conductivity meter, the conductivity σ of the pure polyionic liquid is 1*10 ^-4 S/cm, the Seebeck coefficient S is about 20 μV/K, and the thermal conductivity κ is 0.2 W/(m·K), calculated according to the formula ZT=S ² σT/κ, the ZT value of the pure polyionic liquid at 300K is 0.6*10 ^-8 , the above table 1 is the polyionic liquid prepared in Example 1-6 The thermoelectric performance index comparison chart of the base thermoelectric material. From Table 1, it can be seen that the conductivity of the polyionic liquid film and the polyionic liquid block prepared by the polyionic liquid doped with sulfonic acid and the single-walled carbon nanotube/polyionic liquid composite material The rate σ and ZT value are significantly higher than pure polyionic liquid.

It can be seen from Examples 1-3 that the conductivity σ and ZT value of the polyionic liquid-based thin film thermoelectric material prepared by adding a certain proportion of carbon nanotubes to the polyionic liquid doped with sulfonic acid have improved, and the carbon nanotubes The electrical conductivity σ and ZT value of the polyionic liquid film thermoelectric material with a mass content of 89% and the polyionic liquid-based film thermoelectric material with a carbon nanotube mass content of 64% are basically the same.

It can be seen from Examples 4-6 that the conductivity, Seebeck coefficient and ZT value of the polyionic liquid-based bulk thermoelectric material prepared by adding a certain proportion of carbon nanotubes to the polyionic liquid doped with sulfonic acid have improved. The conductivity and ZT value of the polyionic liquid-based bulk thermoelectric material with a carbon nanotube mass content of 89% are significantly higher than those of the polyionic liquid-based bulk thermoelectric material with a carbon nanotube mass content of 64%.

In summary, the present invention discloses a preparation method of polyionic liquid-based thermoelectric material. The preparation method includes mixing and grinding polyionic liquid with macromolecular sulfonic acid to obtain a polyionic liquid doped with sulfonic acid; The acid-doped polyionic liquid is dissolved in a phenol solvent and stirred to obtain a polyionic liquid solution; then the nanocarbon material is added to the polyionic liquid solution, stirred and dried to obtain a polyionic liquid-based thermoelectric material. In the present invention, the order of arrangement of the molecular chains of the polyionic liquid is initially improved through the interaction of the phenol solvent and the polyionic liquid molecules, and then the orderly accumulation of the polyionic liquid molecules is achieved through the induction of carbon nanotubes by compounding with the nano-carbon material, and further Enhancing the order of arrangement of polyionic liquid molecular chains to obtain high-performance polyionic liquid-based thermoelectric materials.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or changes can be made based on the above description, and all these improvements and changes should fall within the protection scope of the appended claims of the present invention.

Claims (10)

1. A preparation method of polyionic liquid-based thermoelectric material, which is characterized in that it comprises the following steps:

   A. Mix and grind the polyionic liquid with macromolecular sulfonic acid to obtain a polyionic liquid doped with sulfonic acid;

   B. Dissolve the polyionic liquid doped with sulfonic acid in a phenol solvent and stir to obtain a polyionic liquid solution;

   C. Add the nano carbon material to the polyionic liquid solution, stir and dry, to obtain a polyionic liquid-based thermoelectric material.
2. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step A, the structural formula of the polyionic liquid is:

   

   among them,

   
3. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step A, the grinding time is 0.5-5h, and the molar ratio of the polyionic liquid to the macromolecular sulfonic acid is 1.5 ~2.0:1.
4. The method for preparing polyionic liquid-based thermoelectric materials according to claim 1, wherein in step A, the macromolecular sulfonic acid is camphor sulfonic acid, dodecyl benzene sulfonic acid, p-toluene sulfonic acid and/ Or dinonylnaphthalenesulfonic acid.
5. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step B, the phenol solvent is m-methylphenol, p-methylphenol, ethylphenol, 2-chlorophenol and/ Or 2-fluorophenol.
6. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step B, the stirring time is 1-24h, the stirring speed is 100-1000rpm, and the polyionic liquid The mass concentration of the solution is lwt% ~ l0wt%.
7. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step C, the nano-carbon material is carbon nanotube, graphene, carbon fiber or C60.
8. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step C, the content of the nano-carbon material in the polyionic liquid solution is 1 wt% to 90 wt%.
9. The method for preparing a polyionic liquid-based thermoelectric material according to claim 1, wherein in step C, the stirring time is 0.5-12h, and the stirring speed is 100-1000 rpm; the drying conditions For: 20℃～80℃ vacuum drying for 24～120h.
10. A polyionic liquid-based thermoelectric material, characterized in that it is prepared by the preparation method of the polyionic liquid-based thermoelectric material according to any one of claims 1-9.

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