CN111484271A - Method for preparing graphene composite conductive slurry by microwave-ultrasonic and obtained product - Google Patents
Method for preparing graphene composite conductive slurry by microwave-ultrasonic and obtained product Download PDFInfo
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Abstract
The invention discloses a method for preparing graphene composite conductive slurry by microwave-ultrasound and an obtained product thereof, and belongs to the technical field of graphene preparation. The method comprises the following steps: 1) sequentially carrying out acidification intercalation, washing and drying on graphite to obtain expandable graphite; 2) performing primary microwave expansion treatment on expandable graphite under the protection of atmosphere to obtain expanded graphite; 3) mixing expanded graphite with a solvent and a carbon black conductive agent, and performing secondary microwave expansion treatment on the obtained mixture under the protection of atmosphere to obtain pre-slurry; 4) and mixing the pre-slurry with the glue solution, and then carrying out ultrasonic stirring treatment to obtain the graphene composite conductive slurry. The graphene composite conductive slurry prepared by the method provided by the invention has the advantages of complete lamellar structure, good stability and good conductivity.
Description
Technical Field
The invention relates to the technical field of graphene preparation, in particular to a method for preparing graphene composite conductive slurry by microwave-ultrasound and an obtained product.
Background
Graphene is a two-dimensional material with a honeycomb crystal structure formed by single-layer carbon atoms in a hexagonal close-packed form, has many excellent properties such as excellent electrical conductivity, thermal conductivity, mechanical properties, ultra-high specific surface area and the like, is widely concerned by people, and is widely applied to multiple fields such as energy storage, solar optoelectronic devices, transistors, sensors, detectors and the like. However, due to the poor quality of graphene in the graphene slurry, graphene sheet layers are easy to stack and agglomerate, so that the specific surface area of the graphene slurry is greatly reduced. The slurry has poor stability, and the application of graphene as a conductive agent in the lithium ion battery industry is greatly limited.
Patent publication No. CN 109346240A provides a preparation method of graphene conductive slurry, which comprises the steps of putting graphene and a carbon material into NMP, adding superfine carbon powder and superconducting carbon black, carrying out high-pressure homogenization treatment, adding a glue solution, and stirring to obtain the graphene conductive slurry. The patent with publication number CN 109824041 a provides a graphene conductive agent for a lithium battery and a preparation method thereof, and the graphene conductive agent is obtained by ball-milling graphite, a dispersing agent and a solvent with certain mass, and vibrating and separating through a screen mesh. However, the graphene and the solvent are uniformly mixed by a ball mill or a high-pressure homogenizer to prepare the graphene conductive slurry, but the obtained graphene is easy to agglomerate in the slurry, and the stability of the slurry is poor. Patent with publication number CN 108975322 a discloses a method for preparing graphene slurry, which comprises the steps of placing expanded graphite into a dispersion medium, soaking, stirring and ultrasonically stripping to obtain graphene slurry, wherein graphene sheets prepared by the method are thick and poor in quality.
Disclosure of Invention
Aiming at the technical problems of thick graphene sheet layer, poor slurry stability and easy agglomeration in the background technology, the invention provides a method for preparing graphene composite conductive slurry by microwave-ultrasound and an obtained product thereof.
In order to solve the technical problem, the invention provides a method for preparing graphene composite conductive slurry by microwave-ultrasound, which comprises the following steps:
1) sequentially carrying out acidification intercalation, washing and drying on graphite to obtain expandable graphite;
2) performing primary microwave expansion treatment on the expandable graphite obtained in the step 1) under the protection of atmosphere to obtain expanded graphite;
3) mixing the expanded graphite obtained in the step 2) with a solvent and a carbon black conductive agent, and performing secondary microwave expansion treatment on the obtained mixture under the protection of atmosphere to obtain pre-slurry;
the solvent is one or more of N-methyl pyrrolidone, dimethylformamide, diethylformamide, dimethyl sulfoxide, methanol, ethanol, glycol and tetrahydrofuran;
4) mixing the pre-slurry obtained in the step 3) with a glue solution, and then carrying out ultrasonic stirring treatment to obtain graphene composite conductive slurry;
the glue solution is a mixed solution of polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose or styrene butadiene rubber and a solvent.
Preferably, the carbon black conductive agent in the step 3) is conductive carbon black Super P, acetylene black or Ketjen black.
Preferably, the mass concentration of the carbon black conductive agent in the pre-slurry in the step 3) is 0.1-1%.
Preferably, the mass concentration of the solvent in the pre-slurry in the step 3) is 94.0% -99.4%.
Preferably, the mass concentration of the expanded graphite in the pre-slurry in the step 3) is 0.5-5.0%.
Preferably, the microwave power in the first microwave expansion treatment in the step 2) is 500-1500 w, and the time is 3-200 s.
Preferably, the microwave power during the secondary microwave expansion treatment in the step 3) is 500-1000 w, and the time is 3-200 s.
Preferably, the ultrasonic power during the ultrasonic stirring treatment in the step 4) is 600-2000 w, the time is 1-20 h, and the stirring speed is 200-3000 rpm.
Preferably, the intercalating agent in the acidification intercalation in step 1) is at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid, or a mixture of potassium permanganate and at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid; the mass ratio of the graphite to the intercalation agent is 1: 1-5.
The invention also provides the graphene composite conductive slurry prepared by the method.
Compared with the prior art, the invention has the following technical effects:
according to the method for preparing the graphene composite conductive slurry by using the microwave-ultrasonic method, the graphene conductive slurry is prepared by using the microwave-ultrasonic method, and the graphene obtained by the rapid reduction of the high-energy pulse microwave has fewer oxygen-containing functional groups, higher conductivity and more complete structure. The solvent and the carbon black conductive agent can weaken the van der Waals force between the graphite sheet layers, are more favorable for stripping the graphite sheet layers during microwave pyrolysis, can also play a role in preventing the graphite sheet layers from being folded back between the sheet layers, and improve the stability of the slurry. Moreover, the carbon black conductive agent can fill some gaps of the positive electrode material and increase conductive contact points, so that the conductive performance and the heat dissipation performance of the battery are integrally improved. The results of the examples show that: the graphene prepared by the invention has a complete lamellar structure, the plane size is 5-10 mu m, the surface modification is not carried out, the intrinsic characteristic of a two-dimensional lamellar is kept, the conductivity is better, the conductivity is more than 62300S/m, no obvious layering exists in 30 days, the viscosity change is smaller, and the stability is better.
Drawings
Fig. 1 is a scanning electron microscope image of the graphene composite conductive paste prepared in example 1;
fig. 2 is a scanning electron microscope image of the graphene composite conductive paste prepared in example 2;
FIG. 3 is a scanning electron microscope image of the graphene composite conductive paste prepared in comparative example 1;
fig. 4 is a scanning electron microscope image of the graphene composite conductive paste prepared in comparative example 2.
Detailed Description
The invention provides a method for preparing graphene composite conductive slurry by microwave-ultrasound, which comprises the following steps:
1) sequentially carrying out acidification intercalation, washing and drying on graphite to obtain expandable graphite;
2) performing primary microwave expansion treatment on the expandable graphite obtained in the step 1) under the protection of atmosphere to obtain expanded graphite;
3) mixing the expanded graphite obtained in the step 2) with a solvent and a carbon black conductive agent, and performing secondary microwave expansion treatment on the obtained mixture under the protection of atmosphere to obtain pre-slurry;
the solvent is one or more of N-methyl pyrrolidone, dimethylformamide, diethylformamide, dimethyl sulfoxide, methanol, ethanol, glycol and tetrahydrofuran;
4) mixing the pre-slurry obtained in the step 3) with a glue solution, and then carrying out ultrasonic stirring treatment to obtain graphene composite conductive slurry;
the glue solution is a mixed solution of polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose or styrene butadiene rubber and a solvent.
The invention sequentially carries out acidification intercalation, washing and drying on graphite to obtain the expandable graphite. In the present invention, the graphite is preferably graphite powder, flake graphite or artificial graphite; the granularity of the graphite is preferably 100-5000 meshes, and more preferably 2000 meshes. In the invention, the intercalation agent for acidification intercalation is preferably at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid, or a mixture of potassium permanganate and at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid, and more preferably a mixture of potassium permanganate and concentrated sulfuric acid; the mass ratio of the graphite to the intercalation agent is 1: 1-5, and more preferably 1: 2.5. In the invention, the acidification intercalation method is preferably stirring for 60min under the condition of 35 ℃ water bath.
In the invention, the washing mode preferably adopts 5-8% dilute hydrochloric acid washing and deionized water washing in sequence until the solution is neutral. After the washing is completed, the present invention preferably performs filtration. In the invention, the filtration mode is preferably suction filtration, and the specific process is that the expandable graphite suspension which is washed to be neutral by water is put into a buchner funnel of a filter flask, suction filtration is carried out by using qualitative filter paper, a filter cake is left on the filter paper, and the filtrate enters the filter flask. In the present invention, the drying method is preferably vacuum drying. The drying temperature is preferably 40-100 ℃, more preferably 60 ℃, and the drying time is preferably 8-24 hours, more preferably 16 hours.
After the expandable graphite is obtained, the expandable graphite is subjected to primary microwave expansion treatment under the protection of atmosphere to obtain the expandable graphite. In the present invention, the atmosphere is preferably nitrogen or argon. In the invention, the microwave power during the primary microwave expansion treatment is preferably 500-1500 w, and more preferably 1000 w; the time for the first microwave treatment is preferably 3 to 200 seconds, and more preferably 50 seconds.
After the expanded graphite is obtained, the expanded graphite is mixed with a solvent and a carbon black conductive agent, and the obtained mixture is subjected to secondary microwave expansion treatment under the protection of atmosphere to obtain pre-slurry. In the invention, the solvent is one or more of N-methyl pyrrolidone, dimethylformamide, diethylformamide, dimethyl sulfoxide, methanol, ethanol, glycol and tetrahydrofuran. In the invention, the mass concentration of the solvent in the pre-slurry is preferably 94-99.4%, and more preferably 96%.
In the present invention, the carbon black conductive agent is preferably SP (conductive carbon black Super P), acetylene black, or ketjen black. In the present invention, the mass concentration of the carbon black conductive agent in the pre-slurry is preferably 0.1% to 1%, and more preferably 0.5%.
In the invention, the mass concentration of the expanded graphite in the pre-slurry is preferably 0.5-5.0%, and more preferably 2.0%.
In the invention, the solvent and the carbon black conductive agent can weaken van der Waals force between graphite sheets, are more beneficial to stripping of the graphite sheets during microwave pyrolysis, can also play a role in preventing the graphite sheets from being folded back between the sheets, and improve the stability of the graphene slurry. Moreover, the carbon black conductive agent can fill some gaps of the positive electrode material and increase conductive contact points, so that the conductive performance and the heat dissipation performance of the battery are integrally improved.
After the pre-sizing agent is obtained, the pre-sizing agent and the glue solution are mixed and then subjected to ultrasonic stirring treatment, so that the graphene composite conductive sizing agent is obtained. In the invention, the glue solution is a mixed solution of polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose or styrene butadiene rubber and a solvent. The mass volume ratio of the polyvinylidene fluoride, the polytetrafluoroethylene, the carboxymethyl cellulose or the styrene butadiene rubber to the solvent is preferably 1: 25 to 100. In the present invention, the volume ratio of the pre-slurry to the glue solution is preferably 1:1 to 4. In the invention, the glue solution can enable particles in the slurry to form a uniform and stable dispersion structure, the viscosity of the slurry is kept unchanged for a long time, and the slurry cannot settle and lose efficacy due to the placement of the slurry.
According to the invention, the pre-slurry and the glue solution are mixed by ultrasonic stirring, so that graphene sheet layers in the pre-slurry can be further peeled off, the glue solution can better permeate into the graphene sheet layers in the pre-slurry, the pre-slurry and the glue solution are mixed more uniformly, and the state of the obtained graphene slurry is more stable. According to the invention, the graphene conductive slurry is prepared by a microwave-ultrasonic method, and the graphene obtained by high-energy pulse microwave rapid reduction has fewer oxygen-containing functional groups, higher conductivity and more complete structure.
The invention also provides the graphene composite conductive slurry prepared by the method.
In order to further illustrate the present invention, the following embodiments are described in detail, but they should not be construed as limiting the scope of the present invention.
Example 1
Weighing 2000-mesh flake graphite, adopting potassium permanganate as an oxidant, and adopting concentrated sulfuric acid and potassium permanganate as an intercalation agent (the mass ratio of the flake graphite to the potassium permanganate to the concentrated sulfuric acid is 1: 1: 4), and stirring for 60min in a water bath at 35 ℃ to carry out acidification intercalation. And (3) washing the acidified intercalated solution to be neutral by using 5% dilute hydrochloric acid deionized water in sequence, putting the expandable graphite suspension washed to be neutral by using water into a Buchner funnel of a filter flask in a suction filtration mode, carrying out suction filtration by using qualitative filter paper, leaving a filter cake on the filter paper, and putting the filtrate into the filter flask. And (3) carrying out vacuum drying on the filter cake at 60 ℃ for 16 h to obtain the expandable graphite. And placing the expandable graphite into a microwave reactor, and performing microwave puffing treatment for 3s under the protection of nitrogen and with the power of 1500W to obtain the expandable graphite. Mixing 2.5g of the expanded graphite obtained in the step with 47.0g of N-methyl pyrrolidone and 0.5g of conductive carbon black Super P in a microwave reactor at a stirring speed of 600rpm, and then performing secondary microwave expansion treatment for 200s under the protection of a nitrogen atmosphere at a power of 500W to obtain pre-slurry. And (3) carrying out ultrasonic treatment on the pre-slurry obtained in the step and 50.0g of polyvinylidene fluoride (N-methyl pyrrolidone) solution with the mass fraction of 1% in an ultrasonic stirring stripping device with the ultrasonic power of 600W and the stirring speed of 200 rpm for 2h to obtain the graphene composite conductive slurry.
Testing the conductivity and the slurry stability of the prepared graphene composite conductive slurry:
measuring the conductivity of the graphene composite conductive slurry, wherein the test method comprises the following steps: and pressing the sample into a wafer with the diameter of 10mm, and testing by adopting a Guangzhou four-probe conductivity tester, wherein the test result shows that the conductivity of the graphene composite conductive slurry is 62300S/m.
Measuring the stability of the graphene composite conductive slurry, wherein the test method comprises the following steps: the rheological viscosity of the graphene composite conductive slurry sample is tested by adopting an Antopa MCR302 rheometer, the graphene composite conductive slurry sample is led into a closed transparent sample bottle and placed in a 60 ℃ oven, the rheological viscosity is tested again after 24 hours, and the rheological viscosity is tested again after natural standing for 30 days.
Table 1 viscosity of graphene composite conductive paste
As can be seen from table 1, the graphene composite conductive paste prepared in embodiment 1 of the present invention has no significant delamination within 30 days, a small viscosity change, and good stability.
The prepared graphene composite conductive slurry is scanned by a scanning electron microscope (the magnification of the electron microscope is 1 ten thousand times), and the specific scanning result is shown in figure 1, and as can be seen from figure 1, the graphene in the graphene composite conductive slurry prepared by the invention has a complete lamellar structure, the plane size is 5-10 mu m, surface modification is not carried out, and the intrinsic characteristics of a two-dimensional lamellar layer are maintained, so that the graphene composite conductive slurry has better conductivity, meanwhile, the surface of the graphene is more folded, which indicates that the number of the obtained graphene layers is smaller, the conductive carbon black Super P is more uniformly distributed on the graphene lamellar layer, and the dispersion state of the graphene composite conductive slurry is good.
Example 2
Weighing 2000-mesh flake graphite, adopting potassium permanganate as an oxidant, and adopting concentrated phosphoric acid and potassium permanganate as an intercalation agent (the mass ratio of the flake graphite to the potassium permanganate to the concentrated phosphoric acid is 5: 1: 4), and stirring for 60min in a water bath at 35 ℃ to carry out acidification intercalation. Washing with 8% diluted hydrochloric acid and deionized water to neutrality, vacuum filtering, and vacuum filtering with qualitative filter paper to obtain filter cake. And (3) carrying out vacuum drying on the filter cake at 100 ℃ for 24h to obtain expandable graphite, putting the expandable graphite into a microwave reactor, and carrying out microwave puffing treatment for 200s under the protection of nitrogen and with the power controlled at 500W to obtain the expandable graphite. Mixing 0.25g of the expanded graphite obtained in the step with 49.7g of dimethylformamide and 0.05g of Ketjen black in a microwave reactor at a stirring speed of 800rpm, and performing secondary microwave expansion treatment for 3 seconds at a power of 1000W under the protection of a nitrogen atmosphere to obtain pre-slurry. And (3) carrying out ultrasonic treatment on the pre-slurry obtained in the step and 50.0g of polytetrafluoroethylene (DMF) solution with the mass fraction of 1% in an ultrasonic stirring stripping device with the ultrasonic power of 2000W and the stirring speed of 3000rpm for 20h to obtain the graphene composite conductive slurry.
The conductivity and slurry stability of the graphene composite conductive slurry prepared above were tested in the same manner as in example 1.
The conductivity of the graphene composite conductive slurry prepared in embodiment 2 of the invention can reach 65600S/m.
The graphene composite conductive paste prepared in example 2 was subjected to viscosity tests for 0h, 24h (baking in an oven at 60 ℃ for 24 h) and 30d, and the specific test results are shown in table 2.
Table 2 viscosity of graphene composite conductive paste
As can be seen from table 2, the graphene composite conductive paste prepared in embodiment 2 of the present invention has no significant delamination for 30 days, a small viscosity change, and good stability.
The prepared graphene composite conductive slurry is scanned by a scanning electron microscope (the magnification of the electron microscope is 1 ten thousand times), the specific scanning result is shown in fig. 2, and as can be seen from fig. 2, the graphene in the graphene composite conductive slurry prepared by the invention has a complete lamellar structure, the plane size is 5-10 mu m, surface modification is not carried out, and the intrinsic characteristics of a two-dimensional lamellar layer are maintained, so that the graphene composite conductive slurry has better conductivity, meanwhile, the surface of the graphene is more folded, which indicates that the number of the obtained graphene layers is smaller, wherein Ketjen black is uniformly distributed on the graphene lamellar layer, and the dispersion state of the graphene composite conductive slurry is good.
Comparative example 1
Weighing 2000-mesh flake graphite, adopting potassium permanganate as an oxidant and concentrated sulfuric acid as an intercalating agent (the mass ratio of the flake graphite to the potassium permanganate to the concentrated sulfuric acid is 1: 1: 4), and stirring for 60min in a water bath at 35 ℃ to carry out acidification intercalation. Washing the acidified intercalated solution to be neutral by using 5% dilute hydrochloric acid and deionized water, putting the expandable graphite suspension washed to be neutral by using water into a Buchner funnel of a filter flask by adopting a suction filtration mode, carrying out suction filtration by using qualitative filter paper, leaving a filter cake on the filter paper, and putting the filtrate into the filter flask. And (3) carrying out vacuum drying on the filter cake at 60 ℃ for 16 h to obtain the expandable graphite. The expandable graphite was placed in a muffle furnace at 1000 ℃ and expanded for 30 s. Mixing 2.5g of the expanded graphite obtained in the step with 47.0g of N-methyl pyrrolidone, controlling the stirring speed to be 800rpm and the ultrasonic power to be 600W, and carrying out ultrasonic treatment in an ultrasonic stirring stripping device for 2h to obtain the graphene composite conductive slurry.
The conductivity and slurry stability of the graphene conductive slurry prepared above were tested in the same manner as in example 1.
The conductivity of the graphene conductive paste prepared in the comparative example 1 can reach 43400S/m.
The graphene conductive paste prepared in comparative example 1 was subjected to viscosity tests for 0h, 24h (baking in an oven at 60 ℃ for 24 h) and 30d (natural standing), and the specific test results are shown in table 3.
Table 3 viscosity of graphene conductive paste
As can be seen from table 3, the graphene conductive paste prepared in comparative example 1 of the present invention was delaminated in 30 days, and had a large viscosity change and poor stability.
Scanning the prepared graphene conductive slurry by using a scanning electron microscope (the magnification of the electron microscope is 1 ten thousand times), wherein the specific scanning result is shown in fig. 3, and as can be seen from fig. 3, the graphene conductive slurry prepared in the comparative example 1 has complete graphite sheet layers, the plane size of about 10 microns and less sheet layer wrinkles, which indicates that the graphene sheet layers are thicker and the slurry dispersion performance is poorer.
Comparative example 2
Weighing 2000-mesh flake graphite, adopting potassium permanganate as an oxidant and concentrated sulfuric acid as an intercalating agent (the mass ratio of the flake graphite to the potassium permanganate to the concentrated sulfuric acid is 1: 1: 4), and stirring for 60min in a water bath at 35 ℃ to carry out acidification intercalation. Washing the acidified intercalated solution to be neutral by using 5% dilute hydrochloric acid and deionized water, putting the expandable graphite suspension washed to be neutral by using water into a Buchner funnel of a filter flask by adopting a suction filtration mode, carrying out suction filtration by using qualitative filter paper, leaving a filter cake on the filter paper, and putting the filtrate into the filter flask. And (3) carrying out vacuum drying on the filter cake at 60 ℃ for 16 h to obtain the expandable graphite. And placing the expandable graphite into a microwave reactor, and performing microwave puffing treatment for 3s under the protection of nitrogen and with the power of 1500W to obtain the expandable graphite. 3.0g of the expanded graphite obtained in the step and 47.0g of dimethyl sulfoxide are mixed in a microwave reactor at a stirring speed of 600rpm, and then secondary microwave expansion treatment is carried out for 200s under the protection of a nitrogen atmosphere at a power of 500W, so as to obtain pre-slurry. And (3) carrying out ultrasonic treatment on the pre-slurry obtained in the step for 2h in an ultrasonic stirring stripping device with the ultrasonic power of 600W and the stirring speed of 200 rpm to obtain the graphene conductive slurry.
The conductivity and slurry stability of the graphene conductive slurry prepared above were tested in the same manner as in example 1.
The conductivity of the graphene conductive paste prepared in the comparative example 2 can reach 49800S/m.
The graphene conductive paste prepared in comparative example 2 was subjected to viscosity tests for 0h, 24h (baking in an oven at 60 ℃ for 24 h) and 30d, and the specific test results are shown in table 4.
Table 4 viscosity of graphene conductive paste
As can be seen from Table 4, the graphene conductive paste prepared in comparative example 2 of the present invention is delaminated in 30 days, and has large viscosity change and poor stability.
Scanning the prepared graphene conductive paste by using a scanning electron microscope (the magnification of the electron microscope is 1 ten thousand times), wherein the specific scanning result is shown in fig. 4, and as can be seen from fig. 4, the graphene conductive paste prepared in the comparative example 2 has complete graphite sheets, the plane size is about 5-8 μm, the sheets have partial folds, and the thickness of partial sheets of the graphene is smaller.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. The method for preparing the graphene composite conductive slurry by adopting microwave-ultrasound is characterized by comprising the following steps of:
1) sequentially carrying out acidification intercalation, washing and drying on graphite to obtain expandable graphite;
2) performing primary microwave expansion treatment on the expandable graphite obtained in the step 1) under the protection of atmosphere to obtain expanded graphite;
3) mixing the expanded graphite obtained in the step 2) with a solvent and a carbon black conductive agent, and performing secondary microwave expansion treatment on the obtained mixture under the protection of atmosphere to obtain pre-slurry;
the solvent is one or more of N-methyl pyrrolidone, dimethylformamide, diethylformamide, dimethyl sulfoxide, methanol, ethanol, glycol and tetrahydrofuran;
4) mixing the pre-slurry obtained in the step 3) with a glue solution, and then carrying out ultrasonic stirring treatment to obtain graphene composite conductive slurry;
the glue solution is a mixed solution of polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose or styrene butadiene rubber and a solvent.
2. The method for preparing graphene composite conductive paste according to claim 1, wherein the carbon black conductive agent in the step 3) is conductive carbon black Super P, acetylene black or Ketjen black.
3. The method for preparing graphene composite conductive paste according to claim 1 or 2, wherein the mass concentration of the carbon black conductive agent in the pre-paste in the step 3) is 0.1-1%.
4. The method for preparing the graphene composite conductive paste according to claim 1, wherein the mass concentration of the solvent in the pre-paste in the step 3) is 94.0-99.4%.
5. The method for preparing the graphene composite conductive paste according to claim 1, wherein the mass concentration of the expanded graphite in the pre-paste in the step 3) is 0.5-5.0%.
6. The method for preparing graphene composite conductive paste according to claim 1, wherein the microwave power in the first microwave expansion treatment in the step 2) is 500-1500 w, and the time is 3-200 s.
7. The method for preparing graphene composite conductive paste according to claim 1, wherein the microwave power in the secondary microwave expansion treatment in the step 3) is 500-1000 w, and the time is 3-200 s.
8. The method for preparing graphene composite conductive paste according to claim 1, wherein the ultrasonic power during the ultrasonic stirring treatment in the step 4) is 600-2000 w, the time is 1-20 h, and the stirring speed is 200-3000 rpm.
9. The method for preparing graphene composite conductive paste according to claim 1, wherein the intercalation agent during the acidification intercalation in the step 1) is at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid, or a mixture of potassium permanganate and at least one of concentrated sulfuric acid, concentrated nitric acid and concentrated phosphoric acid; the mass ratio of the graphite to the intercalation agent is 1: 1-5.
10. The graphene composite conductive paste prepared by the method of any one of claims 1 to 9.
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| CN112225510A (en) * | 2020-10-21 | 2021-01-15 | 燕山大学 | Conductive carbon black composite cement mortar and preparation method thereof |
| CN114275773A (en) * | 2022-01-19 | 2022-04-05 | 郑州大学 | Method for preparing graphene by using cathode carbon block return material |
| CN114477851A (en) * | 2022-01-24 | 2022-05-13 | 安徽碳华新材料科技有限公司 | Graphene slurry applied to heat dissipation structure of electronic device |
| CN115036510A (en) * | 2022-07-25 | 2022-09-09 | 常州大学 | Additive-free graphene/carbon black composite conductive agent and preparation method and application thereof |
| CN116041986A (en) * | 2022-12-22 | 2023-05-02 | 山西盛达威科技有限公司 | Preparation method of water-soluble carbon black |
| CN116376403A (en) * | 2023-04-25 | 2023-07-04 | 国网江西省电力有限公司电力科学研究院 | Graphene coating and preparation method thereof |
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| CN114275773A (en) * | 2022-01-19 | 2022-04-05 | 郑州大学 | Method for preparing graphene by using cathode carbon block return material |
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| CN116376403A (en) * | 2023-04-25 | 2023-07-04 | 国网江西省电力有限公司电力科学研究院 | Graphene coating and preparation method thereof |
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Application publication date: 20200804 Assignee: Shandong Yiwei New Material Co.,Ltd. Assignor: Shandong Haike Innovation Research Institute Co.,Ltd. Contract record no.: X2022980025055 Denomination of invention: Method for preparing graphene composite conductive paste by microwave ultrasound and its products Granted publication date: 20200918 License type: Common License Record date: 20221206 |
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