An integrated electrode plate, its preparation method and application

Abstract

The application relates to the technical field of all-vanadium redox flow batteries, and discloses an integrated electrode plate and a preparation method and application thereof, which comprises the following steps: mixing and calcining a metal organic framework material and polyvinylpyrrolidone to obtain a porous carbon material; uniformly melting and mixing the porous carbon material, resin and conductive carbon material, and performing die forming to obtain a modified bipolar plate; using silver-coated copper powder as a conductive filler, and using epoxy modified acrylic resin as an organic carrier to prepare ultraviolet light curing silver-coated copper conductive adhesive; and bonding the electrode and the modified bipolar plate through ultraviolet light curing to prepare the integrated electrode plate. The porous carbon is obtained by using a polyvinylpyrrolidone-assisted limited carbonization method, the conductivity of the bipolar plate is improved, epoxy modified acrylic resin is used as the organic carrier, the silver-coated copper powder is uniformly distributed in the organic carrier, the conductivity of the conductive adhesive is improved, and the integrated electrode plate improves the performance of the flow battery.

Description

Technical Field

[0001] This invention relates to the field of vanadium redox flow battery technology, and more particularly to an integrated electrode plate and its preparation method and application. Background Technology

[0002] In recent years, vanadium redox flow batteries have become the focus of energy storage batteries. They have advantages such as independent capacity, high power, long life, deep discharge capability and no emission pollution. They can be used as supporting energy storage devices in the power generation process of renewable energy sources such as wind power and solar energy, and can also play a role in frequency regulation and peak shaving in the power grid system. They are suitable for large-scale electrochemical energy storage devices.

[0003] Bipolar plates are a key component in vanadium redox flow batteries, serving to connect the positive and negative electrodes of each cell in the stack, collect electrons, and isolate the positive and negative electrolytes. Therefore, bipolar plates need high conductivity and stability in strong acid media, as well as low resistivity and low contact resistance with the electrode materials. In vanadium redox flow batteries, bipolar plates and electrodes are often physically stacked, but this method presents several problems: 1) Bipolar plates and graphite felt may shift during assembly; 2) Bipolar plates lack sufficient mechanical strength and are easily damaged under pressure and during use; once damaged, the battery becomes unusable; 3) The physical contact between bipolar plates and electrodes is achieved through pressure, resulting in high contact resistance and affecting stack performance.

[0004] To address these technical problems, an integrated electrode plate, its preparation method, and its application are proposed. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, the present invention provides an integrated electrode plate, its preparation method and application.

[0006] The technical solution adopted in this invention is as follows:

[0007] In a first aspect, the present invention discloses a method for preparing an integrated electrode plate, comprising the following steps:

[0008] Step S1: The metal-organic framework material and polyvinylpyrrolidone are mixed and calcined to obtain a porous carbon material;

[0009] Step S2: The porous carbon material, resin and conductive carbon material are melted, mixed and molded to obtain a modified bipolar plate;

[0010] Step S3: The acrylic resin and reactive diluent are stirred evenly, and 1-hydroxycyclohexylphenyl ketone and benzophenone are added and dispersed evenly to obtain an organic carrier;

[0011] Step S4: Mix the organic carrier and silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive, and apply the silver-coated copper conductive adhesive to both sides of the bipolar plate. Place graphite felt on both sides of the bipolar plate after coating, and cure to obtain an integrated electrode plate.

[0012] In one embodiment, the metal-organic framework material in step S1 is prepared by the following method:

[0013] Zinc nitrate and dimethylimidazole were dissolved separately in methanol solution and then ultrasonically dispersed to obtain a metal-organic framework material; among which,

[0014] The mass ratio of zinc nitrate to dimethylimidazole is (1~1.5):1;

[0015] The ultrasonic dispersion frequency is 50~100Hz, and the time is 10~30min.

[0016] In one embodiment, after mixing the metal-organic framework material and the polyvinylpyrrolidone in step S1, the mixture needs to be allowed to stand and dry to obtain the porous carbon material; wherein...

[0017] The settling time is 24~48 hours;

[0018] The drying temperature is 60~100℃, and the time is 6~12h.

[0019] In one embodiment, the calcination in step S1 has a heating rate of 2~5℃ / min, a temperature of 800~1200℃, and a time of 2~5h.

[0020] In one implementation, in step S2:

[0021] The resin is selected from at least one of polyethylene and polypropylene;

[0022] The conductive carbon material is selected from at least one of carbon black, graphite, carbon fiber, and carbon nanotubes.

[0023] The modified bipolar plate contains 1-5% porous carbon material by mass, 30-70% conductive carbon material by mass, and the remainder is resin.

[0024] In one implementation, in step S2:

[0025] The melting and mixing temperature is 150~200℃, and the time is 30~60min;

[0026] The molding temperature is 150~200℃, the pressure is 50~100Mpa, and the time is 5~10min.

[0027] In one implementation, in step S3:

[0028] The active diluent is trimethylolpropane triacrylate;

[0029] The mass ratio of the reactive diluent to the acrylic resin is 1:(10~20);

[0030] The mass ratio of the acrylic resin, the 1-hydroxycyclohexylphenyl ketone, and the benzophenone is (20~40):1:1.

[0031] In one implementation, in step S4:

[0032] The mass ratio of the organic carrier to the silver-coated copper powder is 1:(2~5);

[0033] The coating thickness of the silver-coated copper conductive adhesive is 50~150μm;

[0034] The curing is carried out under ultraviolet light irradiation, and the power of the ultraviolet light is 20~50W, and the irradiation time is 15~60min.

[0035] Secondly, the present invention discloses an integrated electrode plate, which is prepared by the method for preparing an integrated electrode plate as described above.

[0036] Thirdly, this invention discloses an application of an integrated electrode plate, wherein the integrated electrode plate prepared by the above-described method or the integrated electrode plate described above is applied to a vanadium battery.

[0037] The beneficial effects of this invention are:

[0038] 1. This invention utilizes a polyvinylpyrrolidone-assisted confined carbonization method to obtain porous carbon. The pore size hierarchy distribution and N atom doping characteristics of the porous carbon provide mechanical strength and conductivity for bipolar plates.

[0039] 2. This invention uses silver-coated copper powder as a conductive filler and epoxy-modified acrylic resin as an organic carrier, which makes the silver-coated copper powder uniformly distributed in the organic carrier without agglomeration. The conductive filler reaches the percolation threshold, and the conductive particles are effectively connected to form a conductive path, thereby improving the conductivity and oxidation resistance of the conductive adhesive.

[0040] 3. The present invention bonds the electrodes and plates together by curing with ultraviolet lamps. Due to its fast curing speed, no solvent discharge, no need for forced heating during curing, low curing energy consumption, and good adhesion and solvent resistance of the cured adhesive, the bonding force between the electrodes and bipolar plates is improved, the contact resistance between the electrodes and bipolar plates is reduced, thereby improving the performance of the flow battery. Attached Figure Description

[0041] Figure 1 This is a schematic flowchart of a method for preparing an integrated electrode plate according to the present invention.

[0042] Figure 2 SEM images of PVP / ZIF-8 (a) and porous carbon (b) prepared according to the method for preparing an integrated electrode plate of the present invention. Detailed Implementation

[0043] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the invention or its application or use. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0044] See Figure 1 A method for preparing an integrated electrode plate includes the following steps:

[0045] Step S1: Dissolve zinc nitrate and dimethylimidazole separately in methanol solution and disperse evenly by ultrasonication. Dissolve polyvinylpyrrolidone in methanol solution containing zinc nitrate. Add the methanol solution of dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. Stir evenly, let stand for a period of time, filter and dry to obtain PVP / ZIF-8 composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton material; the mass ratio of zinc nitrate to dimethylimidazole is (1~1.5):1, the mass ratio of zinc nitrate to polyvinylpyrrolidone is 1:(2~3), the ultrasonic dispersion frequency is 50~100Hz, the time is 10~30min, the standing condition is 24~48h, and the drying condition is 60~100℃ for 6~12h.

[0046] Step S2: Place PVP / ZIF-8 into a tube furnace and calcine it under a nitrogen atmosphere to obtain porous carbon material; the calcination conditions are: heating rate of 2~5℃ / min, temperature of 800~1200℃, and time of 2~5h.

[0047] Step S3: The resin, porous carbon material, and conductive carbon material are melted and mixed in an internal mixer, then crushed to obtain modified conductive particles. These particles are placed in a mold and molded using a hot press to obtain a modified bipolar plate. The resin is one of polyethylene or polypropylene, and the conductive carbon material is one or more of carbon black, graphite, carbon fiber, and carbon nanotubes. The porous carbon material content is 1-5 parts, the conductive carbon material content is 30-70 parts, and the remainder is resin. The internal mixer melting temperature is 150-200℃, the time is 30-60 min, and the hot press molding temperature is 150-200℃, the pressure is 50-100 MPa, and the time is 5-10 min.

[0048] Step S4: Add an appropriate amount of acrylic resin to a beaker, then add the reactive diluent trimethylolpropane triacrylate, stir evenly, then add 1-hydroxycyclohexylphenyl ketone and benzophenone, disperse evenly to obtain an organic carrier, mix the organic carrier and silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive; the mass ratio of diluent trimethylolpropane triacrylate to acrylic resin is 1:(10~20), the mass ratio of acrylic resin to 1-hydroxycyclohexylphenyl ketone to benzophenone is (20~40):1:1, and the mass ratio of organic carrier to silver-coated copper powder is 1:(2~5);

[0049] Step S5: Apply the silver-coated copper conductive adhesive to both sides of the bipolar plate, place a graphite felt on each side, and cure under ultraviolet light to obtain an integrated electrode plate; the coating thickness of the silver-coated copper conductive adhesive is 50~150um, the power of the ultraviolet lamp is 20~50W, and the irradiation time is 15~60min.

[0050] Example 1: A method for preparing an integrated electrode plate, comprising the following steps:

[0051] Step S1: Dissolve 2g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 50HZ for 30min. Add 4g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 24h and then filter. Dry in a vacuum oven at 60℃ for 12h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0052] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 800℃ at a heating rate of 2℃ / min under a nitrogen atmosphere. After calcination for 5 hours, porous carbon material is obtained.

[0053] Step S3: 29 parts polyethylene, 1 part porous carbon material, 35 parts graphite and 35 parts carbon black are melted and mixed in an internal mixer at a melting temperature of 180°C for 45 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 200°C, a pressure of 50 MPa and a time of 5 minutes to obtain a modified bipolar plate.

[0054] Step S4: Add 100g of acrylic resin to a beaker, then add 5g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 2.5g of 1-hydroxycyclohexylphenyl ketone and 2.5g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 20g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0055] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 50μm. Place a graphite felt on each side and cure it under a 20W UV lamp for 60 minutes to obtain an integrated electrode plate.

[0056] Example 2: A method for preparing an integrated electrode plate, comprising the following steps:

[0057] Step S1: Dissolve 2g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 60HZ for 25min. Add 6g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 30h and filter. Dry in a vacuum oven at 70℃ for 11h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0058] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 900℃ at a heating rate of 3℃ / min under a nitrogen atmosphere. After calcination for 4 hours, porous carbon material is obtained.

[0059] Step S3: 43 parts polyethylene, 2 parts porous carbon material, 25 parts graphite, 20 parts carbon black and 10 parts carbon fiber are melted and mixed in an internal mixer at a melting temperature of 150°C for 60 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a molding temperature of 150°C, a pressure of 100 MPa and a time of 10 minutes to obtain a modified bipolar plate.

[0060] Step S4: Add 100g of acrylic resin to a beaker, then add 6g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 3g of 1-hydroxycyclohexylphenyl ketone and 3g of benzophenone, disperse evenly to obtain an organic carrier, and then mix 10g of organic carrier and 30g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0061] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 80μm. Place a graphite felt on each side and cure it under a 30W UV lamp for 50 minutes to obtain an integrated electrode plate.

[0062] Example 3: A method for preparing an integrated electrode plate, comprising the following steps:

[0063] Step S1: Dissolve 2.5g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 70HZ for 20min. Add 5g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate, and add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 36h, filter, and dry in an 80℃ vacuum oven for 10h to obtain PVP / ZIF-8 composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton material.

[0064] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1000℃ at a heating rate of 4℃ / min under a nitrogen atmosphere. After calcination for 3 hours, porous carbon material is obtained.

[0065] Step S3: 32 parts polyethylene, 3 parts porous carbon material, 20 parts graphite, 30 parts carbon black, and 15 parts carbon nanotubes are melted and mixed in an internal mixer at a melting temperature of 200°C for 30 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 200°C, a pressure of 50 MPa, and a time of 5 minutes to obtain a modified bipolar plate.

[0066] Step S4: Add 100g of acrylic resin to a beaker, then add 7g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 3.5g of 1-hydroxycyclohexylphenyl ketone and 3.5g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 40g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0067] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 100μm. Place a graphite felt on each side and cure it under a 40W UV lamp for 30 minutes to obtain an integrated electrode plate.

[0068] Example 4: A method for preparing an integrated electrode plate, comprising the following steps:

[0069] Step S1: Dissolve 2.5g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 80HZ for 15min. Add 7.5g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate, and add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 40h, filter, and dry in a vacuum oven at 90℃ for 8h to obtain PVP / ZIF-8 composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton material.

[0070] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1100℃ at a heating rate of 5℃ / min under a nitrogen atmosphere. After calcination for 2 hours, porous carbon material is obtained.

[0071] Step S3: 61 parts polypropylene, 4 parts porous carbon material, 15 parts graphite, 10 parts carbon black, and 10 parts carbon fiber are melted and mixed in an internal mixer at a melting temperature of 180°C for 40 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 160°C, a pressure of 60 MPa, and a time of 6 minutes to obtain a modified bipolar plate.

[0072] Step S4: Add 100g of acrylic resin to a beaker, then add 8g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 4g of 1-hydroxycyclohexylphenyl ketone and 4g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 50g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0073] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 120μm. Place a graphite felt on each side and cure it under a 50W UV lamp for 15 minutes to obtain an integrated electrode plate.

[0074] Example 5: A method for preparing an integrated electrode plate, comprising the following steps:

[0075] Step S1: Dissolve 3g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 90HZ for 15min. Add 6g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 48h and filter. Dry in a vacuum oven at 100℃ for 6h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0076] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1200℃ at a heating rate of 2℃ / min under a nitrogen atmosphere. After calcination for 2 hours, porous carbon material is obtained.

[0077] Step S3: 55 parts polypropylene, 5 parts porous carbon material, 20 parts graphite, 10 parts carbon black, and 10 parts carbon nanotube sheets are melted and mixed in an internal mixer at a melting temperature of 175°C for 50 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 170°C, a pressure of 70 MPa, and a time of 7 minutes to obtain a modified bipolar plate.

[0078] Step S4: Add 100g of acrylic resin to a beaker, then add 9g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 4.5g of 1-hydroxycyclohexylphenyl ketone and 4.5g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 20g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0079] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 150μm. Place a graphite felt on each side and cure it under a 20W UV lamp for 60 minutes to obtain an integrated electrode plate.

[0080] Example 6: A method for preparing an integrated electrode plate, comprising the following steps:

[0081] Step S1: Dissolve 3g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 100HZ for 10min. Add 9g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 24h and then filter. Dry in a vacuum oven at 60℃ for 12h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0082] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 800℃ at a heating rate of 3℃ / min under a nitrogen atmosphere. After calcination for 3 hours, porous carbon material is obtained.

[0083] Step S3: 45 parts polypropylene, 5 parts porous carbon material, 20 parts graphite, 20 parts carbon black, and 10 parts carbon fiber are melted and mixed in an internal mixer at a melting temperature of 170°C for 45 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 180°C, a pressure of 80 MPa, and a time of 8 minutes to obtain a modified bipolar plate.

[0084] Step S4: Add 100g of acrylic resin to a beaker, then add 10g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 5g of 1-hydroxycyclohexylphenyl ketone and 5g of benzophenone, disperse evenly to obtain an organic carrier, and mix 10g of organic carrier and 30g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0085] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 50μm. Place a graphite felt on each side and cure it under a 30W UV lamp for 50 minutes to obtain an integrated electrode plate.

[0086] Example 7: A method for preparing an integrated electrode plate, comprising the following steps:

[0087] Step S1: Dissolve 2.5g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 60HZ for 25min. Add 6g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 30h and filter. Dry in a vacuum oven at 70℃ for 12h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0088] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 900℃ at a heating rate of 4℃ / min under a nitrogen atmosphere. After calcination for 3.5h, porous carbon material is obtained.

[0089] Step S3: 37 parts polyethylene, 3 parts porous carbon material, 25 parts graphite, 25 parts carbon black, and 10 parts carbon nanotubes are melted and mixed in an internal mixer at a melting temperature of 180°C for 40 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 190°C, a pressure of 60 MPa, and a time of 9 minutes to obtain a modified bipolar plate.

[0090] Step S4: Add 100g of acrylic resin to a beaker, then add 6g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 3g of 1-hydroxycyclohexylphenyl ketone and 3g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 40g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0091] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 80μm. Place a graphite felt on each side and cure it under a 40W UV lamp for 40 minutes to obtain an integrated electrode plate.

[0092] Example 8: A method for preparing an integrated electrode plate, comprising the following steps:

[0093] Step S1: Dissolve 3g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 75HZ for 30min. Add 7.5g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate. Add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 36h and filter. Dry in a vacuum oven at 80℃ for 10h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0094] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1000℃ at a heating rate of 5℃ / min under a nitrogen atmosphere. After calcination for 2.5h, porous carbon material is obtained.

[0095] Step S3: 65 parts polypropylene, 5 parts porous carbon material, 10 parts graphite, 10 parts carbon black, and 10 parts carbon nanotubes are melted and mixed in an internal mixer at a melting temperature of 160°C for 35 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 175°C, a pressure of 90 MPa, and a time of 6 minutes to obtain a modified bipolar plate.

[0096] Step S4: Add 100g of acrylic resin to a beaker, then add 7g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 3.5g of 1-hydroxycyclohexylphenyl ketone and 3.5g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 50g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0097] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 100μm. Place a graphite felt on each side and cure it under a 50W UV lamp for 20 minutes to obtain an integrated electrode plate.

[0098] Example 9: A method for preparing an integrated electrode plate, comprising the following steps:

[0099] Step S1: Dissolve 2g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 80HZ for 15min. Add 5g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate, and add the methanol solution of dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 42h, filter, and dry in a vacuum oven at 90℃ for 10h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0100] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1100℃ at a heating rate of 3℃ / min under a nitrogen atmosphere. After calcination for 2.5h, porous carbon material is obtained.

[0101] Step S3: 41 parts polypropylene, 4 parts porous carbon material, 30 parts graphite, 20 parts carbon black and 10 parts carbon fiber are melted and mixed in an internal mixer at a melting temperature of 190°C for 60 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 180°C, a pressure of 60 MPa and a time of 7 minutes to obtain a modified bipolar plate.

[0102] Step S4: Add 100g of acrylic resin to a beaker, then add 8g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 4g of 1-hydroxycyclohexylphenyl ketone and 4g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 25g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0103] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 120μm. Place a graphite felt on each side and cure it under a 30W UV lamp for 35 minutes to obtain an integrated electrode plate.

[0104] Example 10: A method for preparing an integrated electrode plate, comprising the following steps:

[0105] Step S1: Dissolve 2.4g of zinc nitrate and 2g of dimethylimidazole in 100ml of methanol solution respectively, and sonicate at 90HZ for 20min. Add 6g of polyvinylpyrrolidone to the methanol solution containing zinc nitrate, and add the methanol solution containing dimethylimidazole to the mixed solution containing zinc nitrate and polyvinylpyrrolidone. After stirring evenly, let stand for 48h, filter, and dry in a vacuum oven at 100℃ for 8h to obtain PVP / ZIF-8, a composite material of polyvinylpyrrolidone and zeolite imidazole ester skeleton.

[0106] Step S2: Place PVP / ZIF-8 into a tube furnace and heat it to 1200℃ at a heating rate of 3℃ / min under a nitrogen atmosphere. After calcination for 2.5h, porous carbon material is obtained.

[0107] Step S3: 43 parts polypropylene, 2 parts porous carbon material, 25 parts graphite, 25 parts carbon black and 5 parts carbon fiber are melted and mixed in an internal mixer at a melting temperature of 175°C for 30 minutes. The mixture is then crushed to obtain modified conductive particles, which are placed in a mold and molded using a hot press at a temperature of 170°C, a pressure of 80 MPa and a time of 8 minutes to obtain a modified bipolar plate.

[0108] Step S4: Add 100g of acrylic resin to a beaker, then add 9g of reactive diluent trimethylolpropane triacrylate, stir evenly, then add 4.5g of 1-hydroxycyclohexylphenyl ketone and 4.5g of benzophenone, disperse evenly to obtain an organic carrier, then mix 10g of organic carrier and 35g of silver-coated copper powder evenly to obtain silver-coated copper conductive adhesive.

[0109] Step S5: Apply silver-coated copper conductive adhesive to both sides of the bipolar plate with a thickness of 150μm. Place a graphite felt on each side and cure it under a 40W UV lamp for 25 minutes to obtain an integrated electrode plate.

[0110] Comparative Example 1: The only difference between the preparation process of this comparative example and Example 1 is that porous carbon material was not added to the bipolar plate.

[0111] Comparative Example 2: The only difference between the preparation process of this comparative example and Example 1 is that conventional conductive adhesive is used.

[0112] Comparative Example 3: This comparative example is a blank control group, that is, the electrode and bipolar plate are directly physically stacked to assemble the fuel cell stack, which is not integrated into the fabrication process.

[0113] The contact resistance of the integrated electrode plates prepared in Examples 1-10 and Comparative Examples 1-3 was tested using a Burster 2316 precision resistance meter.

[0114] The examples and comparative examples were assembled into fuel cells for testing at a current density of 80 mA / cm². 2 The coulombic efficiency, voltage efficiency, and energy efficiency were recorded. The test results are shown in Table 1.

[0115] Table 1: Battery performance test results using the assembled stacks of the examples and comparative examples.

[0116]

[0117] Therefore, comparing Example 1 with Comparative Example 1, it can be seen that when porous carbon material is added during the bipolar plate preparation process, the resistivity of the prepared bipolar plate is relatively low due to the hierarchical distribution of pore size and N atom doping characteristics of porous carbon, resulting in higher battery stack performance. Comparing Example 1 with Comparative Example 2, it can be seen that the voltage efficiency of the small battery stack in the comparative example is lower. This is because the use of silver-coated copper powder as the conductive filler and epoxy-modified acrylic resin as the organic carrier ensures that the silver-coated copper powder is evenly distributed in the organic carrier without agglomeration. The conductive filler reaches the percolation threshold, and the conductive particles effectively connect to form a conductive path, improving the conductivity and oxidation resistance of the conductive adhesive, while conventional conductive adhesives have poor conductivity. Comparing Example 1 with Comparative Example 3, it can be seen that the lack of an integrated electrode plate leads to a larger contact resistance between the electrode and the plate, thereby reducing battery performance. Therefore, this invention uses ZIF-8 as a precursor material and obtains porous carbon through a polyvinylpyrrolidone-assisted confined carbonization method. The pore size hierarchy distribution and N atom doping characteristics of the porous carbon provide mechanical strength and conductivity for the bipolar plate. Silver-coated copper powder is used as a conductive filler, and epoxy-modified acrylic resin is used as an organic carrier. This ensures that the silver-coated copper powder is evenly distributed in the organic carrier without agglomeration. The conductive filler reaches the percolation threshold, and the conductive particles are effectively connected to form a conductive path, improving the conductivity and oxidation resistance of the conductive adhesive. The electrodes and plates are bonded together by UV curing. Due to its fast curing speed, no solvent discharge, no need for forced heating during curing, low curing energy consumption, and good adhesion and solvent resistance of the cured adhesive, the adhesion between the electrodes and bipolar plates is improved, and the contact resistance between the electrodes and bipolar plates is reduced, thereby improving the performance of the flow battery.

[0118] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of making an integrated electrode pad, comprising: It comprises the following steps: ​ Step S1: mixing and calcining metal organic framework material and polyvinylpyrrolidone to obtain porous carbon material; the metal organic framework material is prepared by the following method: dissolving zinc nitrate and dimethyl imidazole in methanol solution respectively, and uniformly ultrasonic dispersion, to obtain metal organic framework material; wherein the mass ratio of zinc nitrate and dimethyl imidazole is (1-1.5):1; Step S2: melt and mix the porous carbon material, resin and conductive carbon material uniformly, and mold forming to obtain modified bipolar plate; the resin is selected from at least one of polyethylene and polypropylene; the mass fraction of the porous carbon material in the modified bipolar plate is 1-5%, the mass fraction of the conductive carbon material is 30-70%, and the rest is the resin; Step S3: stirring the acrylic resin and active diluent uniformly, adding 1-hydroxycyclohexyl phenyl ketone and benzophenone to disperse uniformly to obtain organic carrier; Step S4: mixing the organic carrier and silver-coated copper powder uniformly to obtain silver-coated copper conductive adhesive, and scraping the silver-coated copper conductive adhesive on the front and back of the bipolar plate, placing graphite felt on the front and back of the scraped bipolar plate, and curing to obtain integrated electrode plate.

2. The method of claim 1, wherein, In the step S1: The frequency of ultrasonic dispersion is 50-100 Hz, and the time is 10-30 min.

3. The method of claim 1, wherein, In the step S1, the metal organic framework material and the polyvinylpyrrolidone after mixing need to be placed, dried to obtain the porous carbon material; wherein, The time of the placement is 24-48 h; The temperature of the drying is 60-100℃, and the time is 6-12 h.

4. The method of claim 1, wherein, In the step S1, the heating rate of the calcination is 2-5℃ / min, the temperature is 800-1200℃, and the time is 2-5 h.

5. The method of claim 1, wherein, In the step S2: The conductive carbon material is selected from at least one of carbon black, graphite, carbon fiber and carbon nanotube.

6. The method of claim 1, wherein, In the step S2: The temperature of the melt and mix uniformly is 150-200℃, and the time is 30-60 min; The temperature of the mold forming is 150-200℃, the pressure is 50-100 Mpa, and the time is 5-10 min.

7. The method of claim 1, wherein, In the step S3: The active diluent is trimethylolpropane triacrylate; The mass ratio of the active diluent and the acrylic resin is 1:(10-20); The mass ratio of the acrylic resin, the 1-hydroxycyclohexyl phenyl ketone and the benzophenone is (20-40):1:

1.

8. The method of claim 1, wherein, In the step S4: The mass ratio of the organic carrier and the silver-coated copper powder is 1:(2-5); The scraping thickness of the silver-coated copper conductive adhesive is 50-150μm; The curing is carried out under the irradiation of ultraviolet lamp, and the power of the ultraviolet lamp is 20-50 W, and the irradiation time is 15-60 min.

9. An integrated electrode pad, characterized by The integrated electrode plate is prepared by the preparation method of the integrated electrode plate according to any one of claims 1-8.

10. Use of an integrated electrode pad, characterized in that The integrated electrode plate prepared by the preparation method of the integrated electrode plate according to any one of claims 1-8 or the integrated electrode plate according to claim 9 is applied to vanadium battery.

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