Integrated single fuel cell structure

Abstract

The invention relates to the technical field of cells, in particular to an integrated single fuel cell structure which comprises a monopolar plate and a membrane electrode, and a gas inlet cavity and a gas outlet cavity are formed in the two sides of the monopolar plate respectively; the monopolar plate comprises an anode monopolar plate and a cathode monopolar plate, and the membrane electrode is fixed and sealed between the anode monopolar plate and the cathode monopolar plate through hot-pressing lamination; hydrophobized carbon paper is arranged on the anode monopole plate and the cathode monopole plate, and runners are arranged on the hydrophobized carbon paper. According to the single fuel cell disclosed by the invention, each component in the single fuel cell is uniformly stressed in the assembling and fixing process, and the positioning precision of the membrane electrode and the polar plate is high.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to an integrated monomer fuel cell structure. Background Art

[0002] Fuel cells can directly convert chemical energy into electrical energy. Their energy conversion efficiency is usually higher than traditional combustion power generation. Their emissions are mainly water, and they do not produce greenhouse gases and other pollutants. They are a clean energy technology.

[0003] A fuel cell stack is composed of multiple cells stacked together, each of which is the basic working unit of the fuel cell stack. A cell generally includes a membrane electrode assembly (MEA), a bipolar plate and a seal. The seal is used to prevent mutual leakage between the reaction gas and the coolant to ensure the airtightness of the stack.

[0004] In existing fuel cell stacks, the commonly used sealing method is to install the sealing ring on the membrane electrode or bipolar plate. Structurally, the membrane electrode and the bipolar plate are separate and need to be stacked alternately during the assembly process, and the sealing of the stack is completed by applying a tightening force to the structure. However, the above-mentioned setting method will cause the membrane electrode and the bipolar plate to have uneven force distribution in the longitudinal direction, and it is difficult to accurately control the assembly size, and it is also difficult to accurately control the compression characteristics of the active area of ​​the membrane electrode. In the transverse direction, different components of the single cell or different areas of the same component will be subjected to uneven forces, and as the number of stacking layers increases, the positioning accuracy of the membrane electrode and the bipolar plate will decrease, which will affect the overall performance of the stack, resulting in uneven heat distribution inside the stack, reducing the consistency of the single-chip voltage of the stack, and accelerating the decline in the performance of the stack. Summary of the invention

[0005] In order to solve the problems in the above background technology, the present invention provides an integrated single fuel cell structure. During the assembly and stacking process of the single fuel cell, each internal component is subjected to uniform force, and the positioning accuracy of the membrane electrode and the plate is high.

[0006] The solution adopted by the present invention to solve the technical problem is: an integrated single fuel cell structure, including a monopolar plate and a membrane electrode, wherein a gas inlet cavity and a gas outlet cavity are respectively provided on both sides of the monopolar plate;

[0007] The monopolar plate comprises an anode monopolar plate and a cathode monopolar plate, and the membrane electrode is fixed and sealed between the anode monopolar plate and the cathode monopolar plate by hot pressing;

[0008] The anode monopolar plate is adhered with a sealing gasket A by a highly conductive glue, and the sealing gasket A is fixed to the periphery of the anode monopolar plate, and a hydrophobic carbon paper is fixedly connected between the gas inlet cavity and the gas outlet cavity of the anode monopolar plate;

[0009] The cathode monopolar plate is pasted with a sealing gasket B by a highly conductive glue, and two sealing gaskets B are provided and respectively fixed to the periphery of the gas inlet cavity and the gas outlet cavity of the cathode monopolar plate, and a hydrophobic carbon paper is fixedly connected between the two sealing gaskets B;

[0010] The hydrophobic carbon paper on the anode monopolar plate and the cathode monopolar plate are both provided with flow channels.

[0011] Furthermore, the flow channel is one of a parallel flow channel, a serpentine flow channel, an interdigitating flow channel or a spiral flow channel.

[0012] Furthermore, the porosity of the hydrophobic carbon paper is 20%-90%, and the thickness of the hydrophobic carbon paper is 50-600μm; on the horizontally placed anode monopolar plate, the top height of the hydrophobic carbon paper and the top height of the sealing gasket A are on the same horizontal plane; on the horizontally placed cathode monopolar plate, the top height of the hydrophobic carbon paper and the top height of the sealing gasket B are on the same horizontal plane.

[0013] Furthermore, the membrane electrode comprises a proton exchange membrane, catalyst layers are arranged on both sides of the proton exchange membrane, a frame membrane is arranged on the side of the catalyst layer away from the proton exchange membrane, and a gas diffusion layer is arranged on the side of the frame membrane away from the catalyst layer.

[0014] Furthermore, the frame film is one or more of PEN, PET, and PPS, and the thickness of the frame film is 40 to 200 μm.

[0015] Furthermore, the monopolar plate is a metal sheet, the surface of the metal sheet is coated with a high-conductive coating, and the thickness of the metal sheet is 0.1 to 100 mm.

[0016] Furthermore, the highly conductive coating is one or two of a carbon coating, a gold coating, and a titanium coating, and the thickness of the highly conductive coating is 1 nm to 100 μm.

[0017] Furthermore, the highly conductive glue is one or more of carbon paste glue, epoxy resin conductive glue, and electronic conductive silver glue.

[0018] In summary, the beneficial effects of the present invention are as follows: the single fuel cell of the present application does not have a sealing ring, but optimizes the combination of the sealing gasket and the plate and forms a sealing structure of the single cell through hot pressing, thereby ensuring the airtightness of the stack and enabling the single polar plate and the membrane electrode to be accurately docked and precisely positioned during the assembly and stacking process;

[0019] The hydrophobic carbon paper cooperates with the sealing gasket and is arranged at different positions of the anode monopolar plate and the cathode monopolar plate. The optimized partitioning arrangement of the hydrophobic carbon paper and the sealing gasket makes it easier to assemble the single battery. At the same time, the structural distribution of each component inside the battery tends to be more straight, so that the stress of each component inside the battery is more uniform when the battery is stacked and assembled;

[0020] The hydrophobic carbon paper is provided with flow channels, which can form excellent water-gas mass transfer channels, thereby meeting the water-gas management requirements of the fuel cell during operation;

[0021] The hydrophobic carbon paper has pores inside. After being compressed, the groove and ridge structure on its flow channel is looser than that on the plate, which is more conducive to gas and liquid transmission and the precise positioning and uniform compression of the membrane electrode and the plate. At the same time, the step of etching the flow channel on the plate is omitted, reducing costs and simplifying the process.

[0022] In addition, the single fuel cell of the present application is conducive to the rapid assembly of subsequent fuel cells and the rapid detection and replacement of individual membrane electrodes.

[0023] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present invention more obvious and easy to understand, the following specifically cites a preferred embodiment and describes it in detail with the accompanying drawings as follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Schematic diagram of the structure of the monopolar plate of this embodiment;

[0025] Figure 2 Schematic diagram of the structure of the anode flow field plate of this embodiment;

[0026] Figure 3 Schematic diagram of the structure of the cathode flow field plate of this embodiment;

[0027] Figure 4 Schematic diagram of the structure of the membrane electrode of this embodiment.

[0028] In the figure: 1. Monopolar plate; 2. Gas inlet; 3. Gas outlet; 4. Sealing gasket A; 5. Sealing gasket B; 6. Membrane electrode with seven-in-one structure; 7. Hydrophobic carbon paper. DETAILED DESCRIPTION

[0029] The single fuel cell of the present application is realized by the following steps:

[0030] (1) Preparation of a monopolar plate 1: A metal sheet is taken, a gas inlet cavity 2 and a gas outlet cavity 3 are respectively provided on both sides of the metal sheet, and a highly conductive coating is coated on the surface of the metal sheet by chemical or physical deposition method to form a monopolar plate 1.

[0031] (2) Arrange an anode flow channel layer on the monopolar plate 1: Take a monopolar plate 1 such as Figure 2 As shown, a sealing gasket A4 is bonded to the periphery of the monopolar plate 1 with a highly conductive glue, and then a hydrophobic carbon paper 7 is fixed between the gas inlet cavity 2 and the gas outlet cavity 3 as a hydrogen flow channel layer, thereby forming a monopolar plate with an anode flow channel layer, i.e., an anode flow field plate. When the anode flow field plate is placed horizontally, the top height of the hydrophobic carbon paper and the top height of the sealing gasket A are located on the same horizontal plane.

[0032] (3) Setting a cathode flow channel layer on the monopolar plate 1: Take a monopolar plate 1 such as Figure 3 As shown, a sealing gasket B5 is bonded to the periphery of the gas inlet cavity 2 and the gas outlet cavity 3 of the monopolar plate 1 with a highly conductive glue, and then a hydrophobic carbon paper 7 is fixed to the middle area of ​​the two sealing gaskets B5 as an air flow channel layer by a highly conductive glue, thereby forming a monopolar plate with a cathode flow channel layer, i.e., a cathode flow field plate. When the anode flow field plate is placed horizontally, the top height of the hydrophobic carbon paper and the top height of the sealing gasket B are located on the same horizontal plane.

[0033] (4) Preparation of membrane electrode: Weigh a certain amount of catalyst, ionomer solution, and solvent according to the stoichiometric ratio, disperse them to form a catalyst layer slurry, and then apply the catalyst layer slurry to both sides of the proton exchange membrane by coating. After drying, a three-layer catalyst coating membrane (CCM) of anode catalyst layer-proton exchange membrane-cathode catalyst layer is formed; then the prepared CCM is encapsulated into two frame films by hot pressing to form a five-in-one membrane electrode; then the gas diffusion layer is attached to both sides of the five-in-one membrane electrode by glue dispensing to form a seven-in-one membrane electrode6. Figure 4 As shown, the structures of the membrane electrode, the anode flow field plate and the cathode flow field plate of the present application are adapted to each other.

[0034] (5) Preparation of an integrated single fuel cell: highly conductive glue is applied to the surface of the sealing gasket A4 of the anode flow field plate, and highly conductive glue is applied to the surface of the sealing gasket B5 with the cathode flow field plate. Then, the anode and cathode of the membrane electrode 6 of the seven-in-one structure obtained in step (4) are respectively corresponding to the cathode flow field plate and the anode flow field plate, and the integrated single fuel cell is assembled by pressing and assembling.

[0035] The present application uses hydrophobic carbon paper 7 as a flow field layer, and a flow channel groove is provided in the flow field layer, and the pore structure of the hydrophobic carbon paper 7 in the flow field layer is combined to form an excellent water gas mass transfer channel, thereby meeting the water gas management needs of the hydrogen fuel cell during operation. At the same time, by sequentially superimposing the cathode gas diffusion layer, the cathode catalyst layer, the proton exchange membrane, the anode catalyst layer and the anode diffusion layer in the middle of the anode and cathode flow field plates, an integrated membrane electrode is finally formed by hot pressing and laminating. The above design avoids and solves the problems of low positioning accuracy and uneven compression caused by the alternating stacking of the membrane electrode and the bipolar plate during the assembly of the stack, and also omits the step of etching the flow channel on the plate, thereby reducing costs and simplifying the process. Through the monomer combustion battery of the present invention, the plug-in assembly and efficient and low-cost production of the fuel cell stack can be achieved.

[0036] Embodiment 1

[0037] (1) Preparation of the monopolar plate 1: A titanium plate with a thickness of 0.8 mm is taken, and a gas inlet cavity 2 and a gas outlet cavity 3 are cut out by stamping. A gold coating is coated on the surface of the titanium plate by a physical deposition method to form the monopolar plate 1.

[0038] (2) Arranging an anode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to bond a 200 μm thick polytetrafluoroethylene (PTFE) sealing gasket A4 to the periphery of the monopolar plate 1, and then use highly conductive glue to fix a 270 μm thick hydrophobic carbon paper 7 Toray TGP-H-090 between the gas inlet cavity 2 and the gas outlet cavity 3 as a hydrogen flow channel layer, thereby forming a monopolar plate with an anode flow channel layer, i.e., an anode flow field plate.

[0039] (3) Setting a cathode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to bond a PTFE sealing gasket B5 with a thickness of 200 μm to the periphery of the gas inlet cavity 2 and the gas outlet cavity 3 of the monopolar plate 1, and then fix a hydrophobic carbon paper 7 Toray TGP-H-090 with a thickness of 270 μm to the middle area of ​​the two sealing gaskets B5 as an air flow channel layer, thereby forming a monopolar plate with a cathode flow channel layer, i.e., a cathode flow field plate.

[0040] (4) Preparation of membrane electrode: HISPEC9100 catalyst and ultrapure water were weighed in a mass ratio of 1:60, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 10,000 rpm; then 3 g of D520, 3 g of ultrapure water and 9 g of isopropanol were added, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 10,000 rpm to form a catalyst layer slurry; then the catalyst layer slurry was coated on both sides of the proton exchange membrane by spraying to achieve a target anode Pt loading of 0.1 mg / cm 2 , the cathode Pt loading is 0.4 mg / cm 2 After drying, a catalyst-coated membrane (CCM) with a three-layer structure of anode catalyst layer-proton exchange membrane-cathode catalyst layer is formed; the prepared CCM is then encapsulated into two PEN frames with a single layer thickness of 45 μm by hot pressing to form a five-in-one membrane electrode; then the gas diffusion layer Toray TGP-H-055 carbon paper is pasted to both sides of the five-in-one membrane electrode by a highly conductive glue in a point-and-glue bonding manner to form a seven-in-one membrane electrode 6;

[0041] (5) Preparation of an integrated single fuel cell: highly conductive glue is applied to the surface of the sealing gasket A4 of the anode flow field plate, and highly conductive glue is applied to the surface of the sealing gasket B5 with the cathode flow field plate. Then, the anode and cathode of the membrane electrode 6 of the seven-in-one structure obtained in step (4) are respectively corresponding to the cathode flow field plate and the anode flow field plate, and the integrated single fuel cell is assembled by pressing and assembling.

[0042] Among them, the high conductive glue in this embodiment is mainly composed of polyvinylidene fluoride (PVDF), high conductive carbon black, N-methylpyrrolidone (1-Methy l-2-pyrrolidi none, NMP), N,N-dimethylformamide (N,N d imethy l formamide, DMF) and water.

[0043] Embodiment 2

[0044] (1) Preparation of the monopolar plate 1: A titanium plate with a thickness of 0.4 mm is taken, and a gas inlet cavity 2 and a gas outlet cavity 3 are cut out by stamping. A carbon coating is coated on the surface of the titanium plate by chemical vapor deposition to form the monopolar plate 1.

[0045] (2) Arranging an anode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to adhere a 100 μm thick silicone sealing gasket A4 to the periphery of the monopolar plate 1, and then use highly conductive glue to fix a 190 μm thick hydrophobic carbon paper 7 (Toray TGP-H-060) between the gas inlet cavity 2 and the gas outlet cavity 3 as a hydrogen flow channel layer, and cut parallel flow channels on the hydrophobic carbon paper 7 by die-cutting, thereby forming a monopolar plate 1 with an anode flow channel layer, i.e., an anode flow field plate.

[0046] (3) Setting a cathode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to bond a 200 μm thick silicone sealing gasket B5 to the periphery of the gas inlet cavity 2 and the gas outlet cavity 3 of the monopolar plate 1, and then fix a 270 μm thick hydrophobic carbon paper 7 (Toray TGP-H-090) to the middle area of ​​the two sealing gaskets B5 as an air flow channel layer, and cut an adaptive flow channel on the hydrophobic carbon paper 7 by die-cutting, thereby forming a monopolar plate 1 with a cathode flow channel layer, i.e., a cathode flow field plate.

[0047] (4) Preparation of membrane electrode: HISPEC9100 catalyst and ultrapure water were weighed in a mass ratio of 1:5, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 12000 rpm; then 2 g of D2020, 3 g of ultrapure water and 2 g of isopropanol were added, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 12000 rpm to form a catalytic layer slurry; then, it was coated on both sides of the proton exchange membrane by slit coating to achieve a target anode Pt loading of 0.1 mg / cm 2 , the cathode Pt loading is 0.4 mg / cm 2 After drying, a catalyst-coated membrane (CCM) with a three-layer structure of anode catalyst layer-proton exchange membrane-cathode catalyst layer is formed; the prepared CCM is then encapsulated into two PEN frames with a single layer thickness of 45 μm by hot pressing to form a five-in-one membrane electrode; then the gas diffusion layer Toray TGP-H-055 carbon paper is pasted to both sides of the five-in-one membrane electrode by glue dispensing to form a seven-in-one membrane electrode 6;

[0048] (5) Preparation of an integrated single fuel cell: highly conductive glue is applied to the surface of the sealing gasket A4 of the anode flow field plate, and highly conductive glue is applied to the surface of the sealing gasket B5 with the cathode flow field plate. Then, the anode and cathode of the membrane electrode 6 of the seven-in-one structure obtained in step (4) are respectively corresponding to the cathode flow field plate and the anode flow field plate, and the integrated single fuel cell is assembled by pressing and assembling.

[0049] Specifically, the conductive filler in the carbon coating in this embodiment is graphene.

[0050] Optionally, in addition to graphene, the conductive filler in the carbon coating may also be activated carbon, graphite and carbon fiber.

[0051] The highly conductive glue in this embodiment is epoxy resin conductive glue.

[0052] Embodiment 3

[0053] (1) Preparation of the monopolar plate 1: A 316 stainless steel plate with a thickness of 0.8 mm is taken, and a gas inlet cavity 2 and a gas outlet cavity 3 are cut out by stamping. A titanium coating is coated on the surface of the titanium plate by chemical vapor deposition to form the monopolar plate 1.

[0054] (2) Arranging an anode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to bond a silicone sealing gasket A4 with a thickness of 100 μm to the periphery of the monopolar plate 1, and then use highly conductive glue to fix a hydrophobic carbon paper 7 (Toray TGP-H-060) with a thickness of 190 μm between the gas inlet chamber 2 and the gas outlet chamber 3 as a hydrogen flow channel layer, and cut a serpentine flow channel on the hydrophobic carbon paper 7 by die-cutting, thereby forming a monopolar plate 1 with an anode flow channel layer, i.e., an anode flow field plate.

[0055] (3) Setting a cathode flow channel layer on the monopolar plate 1: Take a monopolar plate 1, use highly conductive glue to bond a 100 μm thick silicone sealing gasket B5 to the periphery of the gas inlet cavity 2 and the gas outlet cavity 3 of the monopolar plate 1, and then fix a 190 μm thick hydrophobic carbon paper 7 (Toray TGP-H-060) to the middle area of ​​the two sealing gaskets B5 as an air flow channel layer, and cut an adaptive flow channel on the hydrophobic carbon paper 7 by die-cutting, thereby forming a monopolar plate 1 with a cathode flow channel layer, i.e., a cathode flow field plate.

[0056] (4) Preparation of membrane electrode: HISPEC9100 catalyst and ultrapure water were weighed in a mass ratio of 1:5, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 13000 rpm; 2 g of D2020, 3 g of ultrapure water and 2 g of isopropanol were added, mixed evenly, and dispersed by a high-speed shearing machine for 30 minutes at a speed of 13000 rpm to form a catalytic layer slurry; then, it was coated on both sides of the proton exchange membrane by slit coating to achieve a target anode Pt loading of 0.1 mg / cm 2 , the cathode Pt loading is 0.4 mg / cm 2After drying, a catalyst-coated membrane (CCM) with a three-layer structure of anode catalyst layer-proton exchange membrane-cathode catalyst layer is formed; the prepared CCM is then encapsulated into two PEN frames with a single layer thickness of 45 μm by hot pressing to form a five-in-one membrane electrode; then the gas diffusion layer JNTG-BA5C1 carbon paper is pasted to both sides of the five-in-one membrane electrode by a highly conductive glue in a point-and-glue bonding manner to form a seven-in-one membrane electrode 6;

[0057] (5) Preparation of an integrated single fuel cell: highly conductive glue is applied to the surface of the sealing gasket A4 of the anode flow field plate, and highly conductive glue is applied to the surface of the sealing gasket B5 with the cathode flow field plate. Then, the anode and cathode of the membrane electrode 6 of the seven-in-one structure obtained in step (4) are respectively corresponding to the cathode flow field plate and the anode flow field plate, and the integrated single fuel cell is assembled by pressing and assembling.

[0058] The highly conductive glue in this embodiment is electronic conductive silver glue.

[0059] The embodiments described above are only preferred implementation modes of the present invention and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and modifications made by those skilled in the art on the basis of the invention shall fall within the protection scope of the present invention.

Claims

1. An integrated single fuel cell structure, comprising a monopolar plate and a membrane electrode, characterized in that: A gas inlet cavity and a gas outlet cavity are respectively provided on both sides of the monopolar plate; The monopolar plate comprises an anode monopolar plate and a cathode monopolar plate, and the membrane electrode is fixed and sealed between the anode monopolar plate and the cathode monopolar plate by hot pressing; The anode monopolar plate is adhered with a sealing gasket A by a highly conductive glue, and the sealing gasket A is fixed to the periphery of the anode monopolar plate, and a hydrophobic carbon paper is fixedly connected between the gas inlet cavity and the gas outlet cavity of the anode monopolar plate; The cathode monopolar plate is pasted with a sealing gasket B by a highly conductive glue, and two sealing gaskets B are provided and respectively fixed to the periphery of the gas inlet cavity and the gas outlet cavity of the cathode monopolar plate, and a hydrophobic carbon paper is fixedly connected between the two sealing gaskets B; The hydrophobic carbon paper on the anode monopolar plate and the cathode monopolar plate are both provided with flow channels.

2. The integrated single fuel cell structure according to claim 1, characterized in that: The flow channel is one of a parallel flow channel and a serpentine flow channel.

3. The integrated single fuel cell structure according to claim 1, characterized in that: The porosity of the hydrophobized carbon paper is 20%-90%, and the thickness of the hydrophobized carbon paper is 50-600 μm; On the horizontally placed anode monopolar plate, the top height of the hydrophobic carbon paper and the top height of the sealing gasket A are on the same horizontal plane; on the horizontally placed cathode monopolar plate, the top height of the hydrophobic carbon paper and the top height of the sealing gasket B are on the same horizontal plane.

4. The integrated single fuel cell structure according to claim 1, characterized in that: The membrane electrode comprises a proton exchange membrane, catalyst layers are arranged on both sides of the proton exchange membrane, a frame membrane is arranged on the side of the catalyst layer away from the proton exchange membrane, and a gas diffusion layer is arranged on the side of the frame membrane away from the catalyst layer.

5. The integrated single fuel cell structure according to claim 4, characterized in that: The frame film is one or more of PEN, PET, and PPS, and the thickness of the frame film is 40-200 μm.

6. The integrated single fuel cell structure according to claim 1, characterized in that: The monopolar plate is a metal sheet, the surface of the metal sheet is coated with a high-conductivity coating, and the thickness of the metal sheet is 0.1 to 100 mm.

7. The integrated single fuel cell structure according to claim 6, characterized in that: The highly conductive coating is one or two of a carbon coating, a gold coating, and a titanium coating, and the thickness of the highly conductive coating is 1 nm to 100 μm.

8. The integrated single fuel cell structure according to claim 1, characterized in that: The highly conductive glue is one or more of carbon paste glue, epoxy resin conductive glue, and electronic conductive silver glue.

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