A fuel cell polar plate and its preparation method and application

Abstract

The application discloses a fuel cell polar plate and a preparation method and application thereof. The preparation method comprises the following steps: preparing a slurry by using 10%-90% of a graphite matrix and 10%-90% of a conductive filler, and obtaining a metal foil coated with the slurry by using the slurry; preparing a conductive medium by using 5%-40% of a viscosity agent and 60%-95% of metal particles, and obtaining a carbon fiber sheet coated with the conductive medium by using the conductive medium; then, the metal foil coated with the slurry is attached to the carbon fiber sheet coated with the conductive medium to obtain a composite carbon fiber sheet; the metal foil is removed to obtain a prefabricated carbon fiber sheet; finally, the prefabricated carbon fiber sheet is subjected to mold pressing, heat curing and soaking treatment to obtain the fuel cell polar plate. The polar plate prepared by the application has good forming strength, and a bipolar plate with a relatively small thickness can be obtained; the electric pile prepared by using the polar plate has high conductivity, and can meet the use requirement of the electric pile. The preparation method is simple, and is easy to realize batch production or large-scale production.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cell, in particular to a fuel cell polar plate and a preparation method and application thereof. BACKGROUND

[0002] Fuel cell utilizes chemical conversion of fuel and oxygen to generate electricity, and its core component includes a membrane electrode unit. The membrane electrode unit is a combination of a proton-conducting membrane and electrodes (anode and cathode) arranged on both sides of the membrane. A fuel cell is generally composed of a large number of stacked membrane electrode units, and the electrical power of these membrane electrode units is superimposed on each other.

[0003] A fuel cell stack is assembled by a plurality of bipolar plates and membrane electrodes, and the structure is bipolar plate, membrane electrode, bipolar plate, membrane electrode, and so on. The bipolar plate is the main component of the fuel cell stack, and accounts for more than 40% of the overall cost of the fuel cell stack. The bipolar plate plays an important role in separating the anode reactant and the cathode reactant and supporting the entire battery system. The micro-acidic environment inside the fuel cell has relatively high performance requirements for the bipolar plate material. At present, only pure graphite material can completely meet the performance requirements of the bipolar plate material. However, the manufacturing and processing costs of pure graphite material are very high, and the processing is difficult, easy to break, and difficult to mass-produce. At present, there are also metal bipolar plates for preparing fuel cells, but the processing cost of the metal bipolar plate is very high, and the service life is short, and it is easy to be corroded in the long-term use in the acidic environment.

[0004] At present, graphite-based composite bipolar plates have great application potential due to their processing conditions and cost advantages. However, the forming strength of the graphite-based composite bipolar plate is low, and it is unable to press the bipolar plate with a thin thickness. In addition, the electrical conductivity of the graphite-based composite bipolar plate is low, and it is difficult to meet the use needs of the fuel cell stack. SUMMARY

[0005] Therefore, the present application provides a fuel cell polar plate and a preparation method and application thereof, which aims to solve the problems of the existing graphite-based composite bipolar plate, such as low forming strength, inability to press the bipolar plate with a thin thickness, low electrical conductivity of the fuel cell stack prepared by the graphite-based composite bipolar plate, and difficulty in meeting the use needs of the fuel cell stack. The polar plate prepared by the present application has good forming strength, and the bipolar plate with a thin thickness can be obtained. The electrical conductivity of the fuel cell stack prepared by the polar plate is high, and the use needs of the fuel cell stack can be met.

[0006] To achieve the above-mentioned purpose, on one hand, the present application provides a preparation method of a fuel cell polar plate, which includes the following steps:

[0007] S01, dissolving 10%-90% graphite matrix, 10%-90% conductive filler in organic solvent, mixing uniformly to obtain slurry; coating the slurry on one side of the metal foil, drying to obtain the metal foil coated with slurry;

[0008] S02, mixing 5%-40% viscosity and 60%-95% metal particles uniformly to obtain conductive medium, coating the conductive medium on one side of the carbon fiber sheet to obtain the carbon fiber sheet coated with conductive medium;

[0009] S03, adhering the metal foil coated with slurry in step S01 to the carbon fiber sheet coated with conductive medium in step S02 to obtain composite carbon fiber sheet; wherein the side with conductive medium of the carbon fiber sheet coated with conductive medium in step S02 abuts the side with slurry of the metal foil coated with slurry in step S01;

[0010] S04, removing the metal foil of the composite carbon fiber sheet in step S03 to obtain the pre-prepared carbon fiber sheet; drying the pre-prepared carbon fiber sheet, then molding, and then heat curing to obtain the polar plate with one side as gas flow field and the other side as water flow field;

[0011] S05, immersing the polar plate in step S04 in epoxy resin ethanol solution, then washing the surface of the polar plate and then curing the polar plate to obtain the fuel cell polar plate;

[0012] The percentage is weight percentage.

[0013] As a preferred embodiment, in step S01,

[0014] The graphite matrix is one of expanded graphite, flake graphite and microcrystalline graphite or a mixture of at least two thereof.

[0015] The conductive filler is one of carbon black, carbon fiber, nanometer carbon tube and graphene or a mixture of at least two thereof.

[0016] The organic solvent is one of N-methyl pyrrolidone (NMP), anhydrous ethanol (C2H5OH) and dimethylformamide (DMF) or a mixture of at least two thereof.

[0017] The amount of the organic solvent is 30ml-100ml.

[0018] The coating thickness of the slurry is 0.05mm.

[0019] The metal foil is copper foil or aluminum foil.

[0020] The drying condition is 80℃ for 15min.

[0021] As a preferred embodiment, in step S02,

[0022] The adhesive is one of phenol formaldehyde resin (PF), epoxy resin (EP), polyimide (PI), polyvinylidene fluoride (PVDF), polyether sulfone (PES) and polyetherimide (PEI) or a mixture of at least two of them.

[0023] The metal particles are a mixture of metal alloy and non-metal alloy.

[0024] The metal alloy is one of silver, aluminum, copper and gold or a mixture of at least two of them.

[0025] The non-metal alloy is a mixture of one or at least two of metal oxide and metal nitride.

[0026] The coating thickness of the conductive medium is 0.05mm.

[0027] As a preferred embodiment, in step S04,

[0028] The drying condition is drying at 80℃; the molding condition is molding at 5MPa-50MPa.

[0029] The heat curing condition is heat curing at 100℃-350℃ for 5min-180min.

[0030] As a preferred embodiment, in step S05,

[0031] The epoxy resin ethanol solution refers to an ethanol solution containing 5%-30% of epoxy resin by weight percentage.

[0032] The soaking time is 1h-5h.

[0033] The curing is preferably carried out in a water bath at 80℃.

[0034] The bending strength of the fuel cell polar plate is preferably 30MPa-80MPa, and the conductivity is preferably 100S / cm-400S / cm.

[0035] The thinnest thickness of the fuel cell polar plate is preferably 0.20mm-0.30mm.

[0036] In another aspect, the embodiments of the present application also provide a fuel cell polar plate obtained by the above preparation method.

[0037] In still another aspect, the embodiments of the present application also provide the application of the fuel cell polar plate, which can be applied to a fuel cell carbon fiber electrode stack bipolar plate.

[0038] Through the present application, the problems that the existing graphite-based composite bipolar plate has low forming strength, cannot be pressed into a bipolar plate with thin thickness, and the prepared graphite-based composite bipolar plate has low conductivity of the electric pile and is difficult to meet the use needs of the fuel cell electric pile can be solved. The bipolar plate prepared by the present application has good forming strength and can obtain a bipolar plate with thin thickness; the electric pile prepared by the bipolar plate has high conductivity and can meet the use needs of the fuel cell electric pile. The preparation method of the present application is simple, the production cost is low, the production efficiency is high, and batch or large-scale production is easy.

[0039] The implementation, functional features and advantages of the present application will be further described in conjunction with embodiments. DETAILED DESCRIPTION

[0040] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work under the premise of the present application are within the protection scope of the present application.

[0041] It should be noted that if the present application embodiments involve directional indications (such as up, down, left, right, front, back, top, bottom, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0042] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrated; can be mechanical connection, can also be electrical connection; can be directly connected, can also be indirectly connected through an intermediate medium, can be the internal communication of two elements or the interaction relationship between two elements, unless otherwise explicitly limited. For those skilled in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0043] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there can be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there can be a middle element.

[0044] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, the technical solutions of various embodiments can be combined with each other, but it must be based on the realization of ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0045] The performance requirements of the micro-acidic environment inside the fuel cell for the bipolar plate material are relatively high, at present only pure graphite material can completely meet the performance requirements of the bipolar plate material. However, the manufacturing and processing cost of pure graphite material is very high, and the processing is difficult, easy to break, and it is difficult to mass-produce. At present, there are also metal bipolar plates for preparing fuel cells, but the processing cost of metal bipolar plate is very high, and the service life is short, and it is easy to be corroded in the acid environment for a long time. The graphite-based composite bipolar plate has great application potential due to its processing conditions and cost advantages. However, the forming strength of the graphite-based composite bipolar plate is low, and it cannot be pressed into bipolar plate with thin thickness, and the conductivity of the fuel cell stack prepared by the graphite-based composite bipolar plate is low, which is difficult to meet the use needs of the fuel cell stack. Based on this, it is necessary to provide a fuel cell polar plate and a preparation method and application thereof to solve the above technical problems.

[0046] Specifically, to achieve the above object, on the one hand, the present application provides a preparation method of fuel cell polar plate, comprising the following steps:

[0047] S01, 10%-90% graphite matrix, 10%-90% conductive filler is dissolved in organic solvent, mixed uniformly, get slurry, the slurry is coated on one side of the metal foil (the thickness can be set according to the actual use needs), drying, get coated with slurry of metal foil;

[0048] S02, 5%-40% viscosity and 60%-95% metal particles are mixed uniformly to obtain conductive medium, the conductive medium is coated on one side of the carbon fiber sheet (the thickness can be set according to the actual use needs), to obtain the carbon fiber sheet coated with conductive medium;

[0049] S03, the metal foil coated with the slurry in step S01 is attached to the carbon fiber sheet coated with the conductive medium in step S02 (in this way, the slurry can be adhered to the carbon fiber sheet through the adhesive), to obtain a composite carbon fiber sheet; wherein the side of the carbon fiber sheet coated with the conductive medium in step S02, which has the conductive medium, abuts the side of the metal foil coated with the slurry in step S01, which has the slurry;

[0050] S04, the metal foil of the composite carbon fiber sheet in step S03 is removed, to obtain a pre-prepared carbon fiber sheet; the pre-prepared carbon fiber sheet is dried, then molded, and then heat-cured, to obtain a polar plate with one side being a gas flow field surface and the other side being a water flow field surface;

[0051] S05, the polar plate in step S04 is immersed in an epoxy resin ethanol solution, then the surface of the polar plate is rinsed, and then the polar plate is cured, to obtain a fuel cell polar plate;

[0052] The percentage is a weight percentage.

[0053] In the embodiments of the present application, the slurry is prepared with 10%-90% graphite matrix (which can be 10%, or 20%, or 50%, or 80%, or 90%, etc.) and 10%-90% conductive filler (which can be 10%, or 20%, or 50%, or 80%, or 90%, etc.), which can better ensure the conductive performance of the prepared fuel cell polar plate.

[0054] The conductive medium is prepared with 5%-40% adhesive (which can be 5%, or 20%, or 15%, or 30%, or 40%, etc.) and 60%-95% metal particles (which can be 60%, or 70%, or 85%, or 90%, or 95%, etc.), which can better ensure the adhesion of the slurry to the carbon fiber sheet and the conductive performance of the prepared fuel cell polar plate, and effectively reduce the preparation cost.

[0055] As a preferred embodiment, in step S01,

[0056] The graphite matrix is one of expanded graphite, flake graphite, and microcrystalline graphite, or a mixture of at least two thereof.

[0057] The conductive filler is one of carbon black, carbon fiber, nanometer carbon tube, and graphene, or a mixture of at least two thereof.

[0058] The organic solvent is one of N-methyl pyrrolidone (NMP), anhydrous ethanol (C2H5OH), and dimethylformamide (DMF), or a mixture of at least two thereof.

[0059] The amount of the organic solvent is 30ml-100ml. In this way, the conductivity of the fuel cell electrode plate prepared can be better ensured.

[0060] The coating thickness of the slurry is 0.05mm. In this way, the conductivity of the fuel cell electrode plate prepared can be better ensured.

[0061] The metal foil is a copper foil or an aluminum foil.

[0062] The drying condition is drying at 80℃ for 15min.

[0063] As a preferred embodiment, in step S02,

[0064] The adhesive is one of phenol formaldehyde resin (PF), epoxy resin (EP), polyimide (PI), polyvinylidene fluoride (PVDF), polyether sulfone (PES) and polyetherimide (PEI) or a mixture of at least two of them.

[0065] The metal particles are a mixture of metal alloy and non-metal alloy.

[0066] The metal alloy is one of silver, aluminum, copper and gold or a mixture of at least two of them.

[0067] The non-metal alloy is a mixture of one or at least two of metal oxide and metal nitride; such as copper oxide, copper nitride, aluminum oxide, aluminum nitride and silver oxide, etc.

[0068] The coating thickness of the conductive medium is 0.05mm. In this way, the conductivity of the fuel cell electrode plate prepared can be better ensured.

[0069] As a preferred embodiment, in step S04,

[0070] The drying condition is drying at 80℃; the molding condition is molding at 5MPa-50MPa.

[0071] The heat curing condition is heat curing at 100℃-350℃ for 5min-180min. In this way, the conductivity of the fuel cell electrode plate prepared can be better ensured.

[0072] As a preferred embodiment, in step S05,

[0073] The epoxy resin ethanol solution refers to an ethanol solution containing 5%-30% of epoxy resin by weight. In this way, the conductivity of the fuel cell electrode plate prepared can be better ensured.

[0074] The soaking time is 1h-5h.

[0075] The solidification is preferably carried out in a water bath at 80°C. In this way, the electrical conductivity of the fuel cell plate prepared can be better guaranteed.

[0076] The bending strength of the fuel cell plate is preferably 30-80 MPa, and the electrical conductivity is preferably 100-400 S / cm.

[0077] The thinnest thickness of the fuel cell plate is preferably 0.20-0.30 mm.

[0078] In another aspect, the embodiments of the present application also provide a fuel cell plate prepared by the above preparation method.

[0079] In still another aspect, the embodiments of the present application also provide the use of the fuel cell plate, which can be used in a fuel cell carbon fiber stack bipolar plate.

[0080] By the present application, the problems of the prior art, such as low forming strength of the graphite-based composite bipolar plate, inability to press a bipolar plate with a thinner thickness, low electrical conductivity of the stack prepared from the graphite-based composite bipolar plate, and difficulty in meeting the use requirements of the fuel cell stack, can be solved. The bipolar plate prepared by the present application has good forming strength and can obtain a bipolar plate with a thinner thickness. The stack prepared by using the bipolar plate has high electrical conductivity and can meet the use requirements of the fuel cell stack. The preparation method of the present application is simple, has low production cost, is high in production efficiency, and is easy to mass produce.

[0081] Example 1

[0082] A preparation method of a fuel cell plate, comprising the following steps:

[0083] S01, 20% graphite matrix (expanded graphite) and 80% conductive filler (carbon black) are dissolved in 40 ml of organic solvent (N-methyl pyrrolidone) to obtain a slurry; the slurry is coated (coating thickness 0.05 mm) on one side of a metal foil, and baked at 80°C for 15 min to obtain a metal foil coated with the slurry;

[0084] S02, 20% adhesive (phenolic resin) and 80% metal particles (a mixture of silver alloy and copper oxide) are mixed uniformly to obtain a conductive medium; the conductive medium is coated (coating thickness 0.05 mm) on one side of a carbon fiber sheet to obtain a carbon fiber sheet coated with the conductive medium;

[0085] S03. The metal foil coated with slurry in step S01 is attached to the carbon fiber sheet coated with conductive medium in step S02 to obtain a composite carbon fiber sheet; wherein, the side of the carbon fiber sheet coated with conductive medium in step S02 abuts against the side of the metal foil coated with slurry in step S01.

[0086] S04. Remove the metal foil from the composite carbon fiber sheet in step S03 to obtain a pre-fabricated carbon fiber sheet; dry the pre-fabricated carbon fiber sheet at 80°C and then mold it at 5MPa, and then heat-cur it (heat-cur at 100°C for 180 min) to obtain an electrode plate with a gas flow field on one side and a water flow field on the other side.

[0087] S05. The electrode plate from step S04 is immersed in a 5% epoxy resin ethanol solution for 2 hours, then the surface of the electrode plate is rinsed and cured (cured in an 80°C water bath) to obtain the fuel cell electrode plate.

[0088] The resulting fuel cell electrode plate has a thickness of 0.52 mm and a contact resistance of 12.1 mΩ·cm. 2 The electrode has an electrical conductivity of 150 S / cm, a flexural strength of 64 MPa, and a contact angle of 82°. The fuel cell stack made using this electrode has high electrical conductivity, which meets the requirements for fuel cell stack applications.

[0089] Example 2

[0090] A method for preparing a fuel cell electrode plate includes the following steps:

[0091] S01. Dissolve 20% graphite matrix (flake graphite) and 80% conductive filler (carbon fiber) in 40 ml of organic solvent (anhydrous ethanol), mix evenly to obtain a slurry; coat the slurry (coating thickness 0.05 mm) on one side of a metal foil, and bake at 80 °C for 15 min to obtain a metal foil coated with the slurry.

[0092] S02. Mix 20% viscous material (polyimide) and 80% metal particles (a mixture of copper alloy and alumina) evenly to obtain a conductive medium. Coat the conductive medium (coating thickness 0.05 mm) on one side of the carbon fiber sheet to obtain a carbon fiber sheet coated with the conductive medium.

[0093] S03. The metal foil coated with slurry in step S01 is attached to the carbon fiber sheet coated with conductive medium in step S02 to obtain a composite carbon fiber sheet; wherein, the side of the carbon fiber sheet coated with conductive medium in step S02 abuts against the side of the metal foil coated with slurry in step S01.

[0094] S04. Remove the metal foil from the composite carbon fiber sheet in step S03 to obtain a pre-fabricated carbon fiber sheet; dry the pre-fabricated carbon fiber sheet at 80°C and then mold it at 50MPa, and then heat-cur it (heat-cur at 350°C for 5 minutes) to obtain an electrode plate with a gas flow field on one side and a water flow field on the other side.

[0095] S05. The electrode plate from step S04 is immersed in a 5% epoxy resin ethanol solution for 2 hours, then the surface of the electrode plate is rinsed and cured (cured in an 80°C water bath) to obtain the fuel cell electrode plate.

[0096] The resulting fuel cell electrode plate has a thickness of 0.39 mm and a contact resistance of 7.0 mΩ·cm. 2 The electrode has an electrical conductivity of 180 S / cm, a bending strength of 60 MPa, and a contact angle of 83°. The fuel cell stack made using this electrode has high electrical conductivity, which meets the requirements for fuel cell stack applications.

[0097] Example 3

[0098] A method for preparing a fuel cell electrode plate includes the following steps:

[0099] S01. Dissolve 10% graphite matrix (microcrystalline graphite) and 90% conductive filler (carbon nanotubes) in 40 ml of organic solvent (dimethylformamide), mix evenly to obtain a slurry; coat the slurry (coating thickness 0.05 mm) on one side of a metal foil, and bake at 80 °C for 15 min to obtain a metal foil coated with the slurry.

[0100] S02. Mix 20% viscous material (polyvinylidene fluoride) and 80% metal particles (a mixture of copper alloy and aluminum nitride) evenly to obtain a conductive medium. Coat the conductive medium (coating thickness 0.05 mm) onto one side of a carbon fiber sheet to obtain a carbon fiber sheet coated with a conductive medium.

[0101] S03. The metal foil coated with slurry in step S01 is attached to the carbon fiber sheet coated with conductive medium in step S02 to obtain a composite carbon fiber sheet; wherein, the side of the carbon fiber sheet coated with conductive medium in step S02 abuts against the side of the metal foil coated with slurry in step S01.

[0102] S04. Remove the metal foil from the composite carbon fiber sheet in step S03 to obtain a pre-fabricated carbon fiber sheet; dry the pre-fabricated carbon fiber sheet at 80°C and then mold it at 50MPa, and then heat-cur it (heat-cured at 250°C for 80 minutes) to obtain an electrode plate with a gas flow field on one side and a water flow field on the other side.

[0103] S05, soaking the polar plate of step S04 in 5% epoxy ethanol solution for 2 hours, then rinsing the surface of the polar plate and curing the polar plate (curing in 80°C water bath) to obtain a fuel cell polar plate;

[0104] The thickness of the obtained fuel cell polar plate is 0.42 mm, the contact resistance is 6.6 mΩ·cm 2 , the electrical conductivity is 221 S / cm, the bending strength is 62 MPa, and the contact angle is 83°. The fuel cell polar plate is used to prepare an electric pile, and the electric pile has high conductivity, which can meet the use needs of the fuel cell electric pile.

[0105] Example 4

[0106] A method for preparing a fuel cell polar plate comprises the following steps:

[0107] S01, dissolving 10% graphite matrix (a mixture of flake graphite and microcrystalline graphite), 90% conductive filler (a mixture of nanometer carbon tube and graphene) in 40 ml organic solvent (a mixture of anhydrous ethanol and dimethylformamide), mixing uniformly to obtain a slurry, coating (coating thickness 0.05 mm) the slurry on one side of a metal foil, and baking at 80°C for 15 min to obtain a metal foil coated with the slurry;

[0108] S02, uniformly mixing 10% adhesive (a mixture of polyether sulfone and polyether imide) and 90% metal particles (a mixture of aluminum alloy and copper oxide) to obtain a conductive medium, coating (coating thickness 0.05 mm) the conductive medium on one side of a carbon fiber sheet to obtain a carbon fiber sheet coated with the conductive medium;

[0109] S03, attaching the metal foil coated with the slurry in step S01 to the carbon fiber sheet coated with the conductive medium in step S02 to obtain a composite carbon fiber sheet; wherein the side of the carbon fiber sheet coated with the conductive medium in step S02 abuts against the side of the metal foil coated with the slurry in step S01;

[0110] S04, removing the metal foil of the composite carbon fiber sheet in step S03 to obtain a preformed carbon fiber sheet; drying the preformed carbon fiber sheet at 80°C, then molding under 50 MPa, and then heat curing (heat curing at 150°C for 120 min) to obtain a polar plate with one side being a gas flow field surface and the other side being a water flow field surface;

[0111] S05, soaking the polar plate of step S04 in 5% epoxy ethanol solution for 2 hours, then rinsing the surface of the polar plate and curing the polar plate (curing in 80°C water bath) to obtain a fuel cell polar plate;

[0112] The thickness of the obtained fuel cell polar plate is 0.40 mm, the contact resistance is 5.8 mΩ·cm, the conductivity is 280 S / cm, the bending strength is 56 MPa, and the contact angle is 86°. The fuel cell polar plate is used to prepare a fuel cell stack, and the conductivity of the fuel cell stack is high, which can meet the use requirement of the fuel cell stack. 2 , the conductivity is 280 S / cm; the bending strength is 56 MPa; and the contact angle is 86°. The fuel cell polar plate is used to prepare a fuel cell stack, and the conductivity of the fuel cell stack is high, which can meet the use requirement of the fuel cell stack.

[0113] The above merely describes the preferred embodiments of the present application, and is not intended to limit the patent scope of the present application. Any equivalent structural transformation, direct / indirect application in other related technical fields, or the like, which is made based on the content of the present application, falls within the patent protection scope of the present application.

Claims

1. A method for preparing fuel cell electrode plates, characterized in that, Includes the following steps: S01. Dissolve 10%-90% graphite matrix and 10%-90% conductive filler in an organic solvent, mix them evenly to obtain a slurry; coat the slurry onto one side of a metal foil, dry it to obtain a metal foil coated with the slurry; the coating thickness of the slurry is 0.05 mm. S02. Mix 5%-40% of viscous material and 60%-95% of metal particles evenly to obtain a conductive medium. Coat the conductive medium onto one side of a carbon fiber sheet to obtain a carbon fiber sheet coated with the conductive medium. The coating thickness of the conductive medium is 0.05 mm. S03. The metal foil coated with slurry in step S01 is attached to the carbon fiber sheet coated with conductive medium in step S02 to obtain a composite carbon fiber sheet; wherein, the side of the carbon fiber sheet coated with conductive medium in step S02 abuts against the side of the metal foil coated with slurry in step S01. S04. Remove the metal foil from the composite carbon fiber sheet in step S03 to obtain a pre-fabricated carbon fiber sheet; dry the pre-fabricated carbon fiber sheet and then mold it, and then heat-cur it to obtain an electrode plate with a gas flow field on one side and a water flow field on the other side. S05. The electrode plate from step S04 is immersed in an epoxy resin ethanol solution, then the surface of the electrode plate is rinsed and cured to obtain the fuel cell electrode plate. The percentage is a weight percentage; In step S04, the drying conditions are drying at 80°C; the molding conditions are molding at 5MPa-50MPa; and the heat curing conditions are heat curing at 100°C-350°C for 5min-180min. In step S05, the bending strength of the fuel cell electrode plate is 30MPa-80MPa, and the conductivity is 100 S / cm-400 S / cm. The thinnest part of the fuel cell electrode plate is 0.20mm-0.30mm thick.

2. The method for preparing fuel cell electrode plates according to claim 1, characterized in that, In step S01, The graphite matrix is ​​one or a mixture of at least two of expanded graphite, flake graphite and microcrystalline graphite; The conductive filler is one or a mixture of at least two of carbon black, carbon fiber, carbon nanotubes and graphene. The organic solvent is one or a mixture of at least two of N-methylpyrrolidone, anhydrous ethanol, and dimethylformamide.

3. The method for preparing fuel cell plates according to claim 1, characterized in that, In step S01, the amount of organic solvent used is 30 ml to 100 ml; the metal foil is copper foil or aluminum foil.

4. The method for preparing fuel cell electrode plates according to claim 1, characterized in that, In step S02, The adhesive is one or a mixture of at least two of the following: phenolic resin, epoxy resin, polyimide, polyvinylidene fluoride, polyethersulfone, and polyetherimide. The metal particles are a mixture of metal alloys and non-metal alloys.

5. The method for preparing fuel cell electrode plates according to claim 4, characterized in that, The metal alloy is one or a mixture of at least two of silver, aluminum, copper and gold; The non-metallic alloy is one or a mixture of at least two of metal oxides and metal nitrides.

6. The method for preparing fuel cell plates according to claim 1, characterized in that, In step S05, the epoxy resin ethanol solution refers to an ethanol solution containing 5%-30% epoxy resin by weight; the soaking time is 1-5 hours; and the curing is carried out in an 80°C water bath.

7. A fuel cell electrode plate, characterized in that, It is prepared by the preparation method according to any one of claims 1 to 6.

8. The application of the fuel cell electrode plate according to claim 7, characterized in that, The fuel cell electrode plates are used in the bipolar plates of the carbon fiber stack of fuel cells.