Preparation method of all-vanadium redox flow battery organic material and nanomaterial bipolar plate

Abstract

The application discloses a kind of preparation methods of all-vanadium redox flow battery organic material and nanometer material bipolar plate, step 1, preparation raw materials: selecting appropriate organic material and nanometer material as raw materials;Step 2, preparation forms white glue;Step 3, preparation forms black glue;Step 4, dry PVDF powder and dry graphite powder are mixed with the proportion of mass ratio 2:1~1:7 and sieved, and dry mixture is prepared;Step 5, the black glue obtained is placed in the blender, the dry mixture is added to the black glue under the condition that the blender is stirred at medium speed, and then continue to stir for a certain period of time to form slurry;Step 6, the slurry prepared in step 5 is poured into the casting mold with release agent uniformly sprayed on the inner surface, and the slurry is scraped flat, and the coating is completed;The application has the advantages of simple process, good repeatability, easy implementation, fast production speed, high efficiency and good consistency of the produced products compared with the existing production process.

Description

Technical Field

[0001] This invention relates to the field of flow technology, specifically to a method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery. Background Technology

[0002] Vanadium redox flow batteries, also known as vanadium redox flow batteries, are a type of green and environmentally friendly battery. As vanadium battery technology matures, the development and application of large-scale stacks have become a core research focus. The stack is the core component of the vanadium redox flow battery, the sole site of chemical-to-electrical energy conversion; its electrical performance directly affects the performance of the entire battery system. With technological advancements, the requirements for stacks are becoming increasingly stringent, demanding small size and light weight, while also imposing stricter requirements on all stack materials, such as bipolar plates.

[0003] Currently, the main bipolar plates for vanadium batteries are graphite plates. However, graphite plates are expensive, have high hardness, are easily broken, and are difficult to process. Conductive plastics have poor conductivity, are thicker, have higher costs, and have high mechanical strength.

[0004] Therefore, a method for preparing organic and nanomaterial bipolar plates for all-vanadium redox flow batteries has become an urgent problem to be solved. Summary of the Invention

[0005] The technical problem to be solved by this invention is that currently, the bipolar plates of vanadium batteries are mainly graphite plates. However, graphite plates are expensive, have high hardness, are easy to break, and are difficult to process. Conductive plastics have poor conductivity, are thick, have high cost, and high mechanical strength.

[0006] To solve the above-mentioned technical problems, the technical solution provided by the present invention is as follows: a method for preparing an organic material and nanomaterial bipolar plate for a vanadium redox flow battery, wherein the method for preparing the organic material and nanomaterial bipolar plate for a vanadium redox flow battery is as follows:

[0007] Step 1: Prepare raw materials: Select appropriate organic materials and nanomaterials as raw materials, including but not limited to polymer composite materials, conductive polymer materials, nano-carbon materials and nano-metal oxides;

[0008] Step 2: Prepare and stir the materials according to the mass ratio of NMP:PVDF:ethanol = 2:1:0.5 to 12:1:0.1 to form white glue;

[0009] Step 3: Mix conductive carbon black and NMP in a mass ratio of 2:1 to 12:1 and stir evenly. Then pour the mixture into the white glue prepared in Step 2 to form a mixture and stir at high speed to form black glue.

[0010] Step 4: Mix the dried PVDF powder and the dried graphite powder in a mass ratio of 2:1 to 1:7 and sieve to prepare a dry mixture.

[0011] Step 5: Place the obtained black glue in a mixer, and while keeping the mixer at medium speed, add the obtained dry mixture to the black glue, and then continue to mix for a certain period of time to form a slurry.

[0012] Step 6: Pour the slurry prepared in step 5 into the casting mold whose inner surface is evenly sprayed with release agent, and smooth the slurry to complete the coating.

[0013] Step 7: Dry the casting mold coated in Step 6 to form a film, thus obtaining a bipolar plate.

[0014] Furthermore, in step 2, the stirring speed is 1000-2000 rpm, and the stirring time is 2 hours.

[0015] Furthermore, the conductive carbon black mentioned in step 3 is acetylene black, Ketjen black, superconducting carbon black, SP, ECP, or BlackPearls.

[0016] Furthermore, the stirring speed in step 3 is 5000-6000 rpm, and the stirring time is 2 hours.

[0017] Further, step 4 specifically involves drying PVDF powder and graphite powder at a temperature of 80℃~140℃ for 8~12h; mixing the dried PVDF powder and graphite powder at a ratio of 2:1~1:7 for 30min, and then sieving to obtain a dry mixture.

[0018] Furthermore, the graphite in step 4 is flake graphite, expanded graphite, microcrystalline graphite, spherical graphite, or KS series conductive graphite.

[0019] Furthermore, the time period in step 5 is 2.5 hours.

[0020] Further, step 7 specifically involves placing the casting mold coated in step 6 onto a heating plate and drying it at a temperature of 110℃ to 170℃ for 3 to 5 hours to form a film and obtain a bipolar plate.

[0021] The advantages of this invention compared to existing technologies are as follows: the process of this invention is simple, repeatable, and easy to implement. Compared with existing production processes, it has a faster production speed, higher efficiency, and better product consistency. Since the bipolar plate is prepared by drying film using a casting method, it has the characteristics of being thin, light, smooth, having excellent conductivity, low resistivity, and good mechanical properties. This bipolar plate can be used as the dual electrode of fuel cells and other flow batteries, and can also be used to make shielding materials, heating elements, etc. This invention is reasonably designed and deserves widespread promotion. Detailed Implementation

[0022] The following provides a more detailed description of the preparation method of the organic and nanomaterial bipolar plate for an all-vanadium redox flow battery according to the present invention.

[0023] The present invention will be described in detail below.

[0024] A method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery is disclosed, the method of which is as follows:

[0025] Step 1: Prepare raw materials: Select appropriate organic materials and nanomaterials as raw materials, including but not limited to polymer composite materials, conductive polymer materials, nano-carbon materials and nano-metal oxides;

[0026] Step 2: Prepare and stir the materials according to the mass ratio of NMP:PVDF:ethanol = 2:1:0.5 to 12:1:0.1 to form white glue;

[0027] Step 3: Mix conductive carbon black and NMP in a mass ratio of 2:1 to 12:1 and stir evenly. Then pour the mixture into the white glue prepared in Step 2 to form a mixture and stir at high speed to form black glue.

[0028] Step 4: Mix the dried PVDF powder and the dried graphite powder in a mass ratio of 2:1 to 1:7 and sieve to prepare a dry mixture.

[0029] Step 5: Place the obtained black glue in a mixer, and while keeping the mixer at medium speed, add the obtained dry mixture to the black glue, and then continue to mix for a certain period of time to form a slurry.

[0030] Step 6: Pour the slurry prepared in step 5 into the casting mold whose inner surface is evenly sprayed with release agent, and smooth the slurry to complete the coating.

[0031] Step 7: Dry the casting mold coated in Step 6 to form a film, thus obtaining a bipolar plate.

[0032] The stirring speed in step 2 is 1000-2000 rpm, and the stirring time is 2 hours.

[0033] The conductive carbon black mentioned in step 3 is acetylene black, Ketjen black, superconducting carbon black, SP, ECP, or Black Pearls.

[0034] The stirring speed in step 3 is 5000-6000 rpm, and the stirring time is 2 hours.

[0035] Step 4 involves drying PVDF powder and graphite powder at a temperature of 80℃ to 140℃ for 8 to 12 hours. The dried PVDF powder and graphite powder are then mixed at a ratio of 2:1 to 1:7 for 30 minutes and sieved to obtain a dry mixture.

[0036] The graphite in step 4 is flake graphite, expanded graphite, microcrystalline graphite, spherical graphite, or KS series conductive graphite.

[0037] The specified time in step 5 is 2.5 hours.

[0038] Step 7 involves placing the casting mold coated in step 6 onto a heating plate and drying it at a temperature of 110℃ to 170℃ for 3 to 5 hours to form a bipolar plate.

[0039] The specific implementation process of the preparation method of organic material and nanomaterial bipolar plate for vanadium redox flow battery of the present invention is as follows: the materials are prepared according to the mass ratio of NMP:PVDF:ethanol = 2:1:0.5 to 12:1:0.1, and stirred at a medium speed of 1000 to 2000 rpm for 2 hours to form white glue;

[0040] The conductive carbon black and NMP are mixed in a mass ratio of 2:1 to 12:1 and stirred evenly. Then, the mixture is poured into the white glue prepared in the previous step and stirred at high speed of 5000 to 6000 rpm for 2 hours to form black glue.

[0041] Conductive carbon black is used as part of the bipolar plate. The conductive carbon black can be acetylene black, Ketjen black, superconducting carbon black, SP, ECP, Black Pearls, carbon nanotubes, graphene and other carbon materials with good conductivity.

[0042] PVDF powder and graphite powder are dried at a drying temperature of 80℃~140℃ for 8~12h. Then, PVDF powder and graphite powder are mixed in a mass ratio of 2:1~1:7 for 30min. After sieving, a dry mixture is prepared.

[0043] The graphite may be one or more of the following: micro-flake graphite, flake graphite, expanded graphite, microcrystalline graphite, ultrafine carbon fiber, spherical graphite, mesophase carbon microspheres, or KS series conductive graphite.

[0044] Place the black glue obtained above in a mixer, and while keeping the mixer at a medium speed, add the dry mixture obtained above to the black glue, and then continue to stir at the existing stirring speed for 2.5 hours to form a uniform slurry. The medium speed is generally 1000 to 2000 rpm.

[0045] The raw materials produced through the above steps consist of conductive carbon black, NMP, graphite, PVDF powder, and anhydrous ethanol, with a composition ratio between 0.5:36:1.3:2.5:1 and 10:100:25:25.7:8.3.

[0046] Beforehand, a release agent is evenly sprayed onto the inner surface of the casting mold. Then, the slurry prepared in the previous step is poured into the casting mold and the slurry is smoothed to complete the coating. The casting mold is dried at a drying temperature of 110℃~170℃ to form a film and obtain a bipolar plate. The drying time is 3h~5h.

[0047] Cool the bipolar plate and casting mold for 10 minutes, then gently remove the bipolar plate with a knife and trim the burrs on the bipolar plate.

[0048] The bipolar plate prepared using the above method yielded the following test results:

[0049] Table 1. Test Results of Bipolar Plates

[0050]

[0051] The process of this invention is simple, reproducible, and easy to implement. Compared with existing production processes, it has the advantages of fast production speed, high efficiency, and good product consistency. Since the bipolar plate is prepared by drying film formation using a casting method, it is thin, smooth, has excellent conductivity, low resistivity, and good mechanical properties. This bipolar plate can be used as the dual electrode of fuel cells and other flow batteries, and can also be used to make shielding materials, heating elements, etc. The design of this invention is reasonable and worthy of widespread promotion.

[0052] The present invention and its embodiments have been described above, and such description is not restrictive. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A method for preparing an organic and nanomaterial bipolar plate for an all-vanadium redox flow battery, characterized in that: The preparation method of the organic material and nanomaterial bipolar plate of the all-vanadium redox flow battery is as follows: Step 1: Prepare raw materials: Select appropriate organic materials and nanomaterials as raw materials, including but not limited to polymer composite materials, conductive polymer materials, nano-carbon materials and nano-metal oxides; Step 2: Prepare and stir the materials according to the mass ratio of NMP:PVDF:ethanol = 2:1:0.5 to 12:1:0.1 to form white glue; Step 3: Mix conductive carbon black and NMP in a mass ratio of 2:1 to 12:1 and stir evenly. Then pour the mixture into the white glue prepared in Step 2 to form a mixture and stir at high speed to form black glue. Step 4: Mix the dry PVDF powder and the dry graphite powder in a mass ratio of 2:1 to 1:7 and sieve to prepare a dry mixture. Step 5: Place the obtained black glue in a mixer, and while keeping the mixer at medium speed, add the obtained dry mixture to the black glue, and then continue to mix for a certain period of time to form a slurry. Step 6: Pour the slurry prepared in step 5 into the casting mold whose inner surface is evenly sprayed with release agent, and smooth the slurry to complete the coating. Step 7: Dry the casting mold coated in Step 6 to form a film, thus obtaining a bipolar plate.

2. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: The stirring speed in step 2 is 1000-2000 rpm, and the stirring time is 2 hours.

3. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: The conductive carbon black mentioned in step 3 is acetylene black, Ketjen black, superconducting carbon black, SP, ECP, or BlackPearls.

4. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: The stirring speed in step 3 is 5000-6000 rpm, and the stirring time is 2 hours.

5. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: Step 4 involves drying PVDF powder and graphite powder at a temperature of 80℃ to 140℃ for 8 to 12 hours. The dried PVDF powder and graphite powder are then mixed at a ratio of 2:1 to 1:7 for 30 minutes and sieved to obtain a dry mixture.

6. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: The graphite in step 4 is flake graphite, expanded graphite, microcrystalline graphite, spherical graphite, or KS series conductive graphite.

7. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: The specified time in step 5 is 2.5 hours.

8. The method for preparing an organic and nanomaterial bipolar plate for a vanadium redox flow battery according to claim 1, characterized in that: Step 7 involves placing the casting mold coated in step 6 onto a heating plate and drying it at a temperature of 110℃ to 170℃ for 3 to 5 hours to form a bipolar plate.

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