Fuel cell monomer and preparation method thereof, fuel cell stack and electric equipment

Abstract

The embodiment of the invention provides a fuel cell monomer and a preparation method thereof, a fuel cell stack and electric equipment, and in the preparation method, a cathode plate, a membrane electrode and an anode plate are combined into a whole through a cathode adhesive film and an anode adhesive film in a step-by-step hot-pressing lamination mode; the thickness of the sealing area of the integrated cell monomer can reach the micron level through a simple mold and process control, and the problems of airtight leakage, poor contact and the like caused by uneven thickness can be effectively improved, so that the qualified rate of integrated preparation of the cell monomer is improved, the consistency of fuel cell stack assembly is more facilitated, and the production efficiency is improved. Meanwhile, the weight and the thickness of a single battery are effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a fuel cell monomer and a preparation method thereof, a fuel cell stack, and electrical equipment. Background Art

[0002] The fuel cell monomer is the core component of the proton exchange membrane fuel cell (PEMFC), which is responsible for the electrochemical reaction of hydrogen and oxygen to generate water and output electrical energy.

[0003] The design of a fuel cell monomer mainly adopts a structure of stacking bipolar plates and membrane electrode assemblies (MEAs), wherein the MEA includes a proton exchange membrane, a catalyst layer, and a gas diffusion layer.

[0004] Existing fuel cell monomers are formed by screen printing followed by integrated hot pressing. Once a single cell is found to be airtight, it is extremely difficult to separate the components and re-hot press them, resulting in a low pass rate for the preparation of integrated single cells. Summary of the Invention

[0005] The embodiments of the present application provide a fuel cell monomer and a preparation method thereof, a fuel cell stack and an electrical device, aiming to improve the problem that fuel cell monomers prepared by existing methods are prone to uneven thickness, resulting in airtight leakage and poor contact.

[0006] In order to solve the above problems, this application is implemented through the following technical solutions:

[0007] This application proposes a method for preparing a fuel cell monomer, comprising:

[0008] Providing a cathode plate, the cathode plate comprising a cathode plate body, the cathode plate body comprising a first surface, the first surface comprising a first region and a second region different from the first region, the first region being used to seal with the cathode catalyst layer of the membrane electrode, and the second region being a cathode reaction region;

[0009] Hot pressing and laminating a cathode film in the first region to form a cathode;

[0010] Providing an anode plate, the anode plate comprising an anode plate body, the anode plate body comprising a third surface, the third surface comprising a third region and a fourth region different from the third region, the third region being used to seal with the anode catalyst layer of the membrane electrode, and the fourth region being an anode reaction region;

[0011] Hot pressing and laminating an anode film in the third region to form an anode;

[0012] The anode, membrane electrode and cathode are stacked in sequence with the first surface facing the cathode catalyst layer and the third surface facing the anode catalyst layer, and then hot-pressed and cured to form a single cell.

[0013] In the preparation method provided in the embodiment of the present application, the cathode plate, membrane electrode and anode plate are combined into one by step-by-step hot pressing and bonding through the cathode film and the anode film. The thickness of the sealing area of ​​the integrated battery cell can reach the micron level through simple molds and process control, which can effectively improve the problems of airtight leakage and poor contact caused by uneven thickness, thereby improving the qualified rate of the integrated preparation of battery cells, being more conducive to the consistency of the fuel cell stack assembly, and effectively reducing the weight and thickness of the single cell.

[0014] Furthermore, in the preparation method, a cathode plate body is provided, comprising:

[0015] The first surface of the cathode plate body after stamping is shielded in a first area, and then the second area is plated with a conductive anti-corrosion coating; or

[0016] Plating a conductive anti-corrosion coating on the first surface of the stamped cathode plate body, then removing the conductive anti-corrosion coating in a first area of ​​the first surface, and retaining the conductive anti-corrosion coating in a second area;

[0017] Provide anode plate body, including:

[0018] The third surface of the stamped anode plate body is shielded in a third area, and then a conductive anti-corrosion coating is plated in the fourth area; or

[0019] The third surface of the stamped anode plate body is plated with a conductive anti-corrosion coating, the conductive anti-corrosion coating in the third area of ​​the third surface is removed, and the conductive anti-corrosion coating in the fourth area is retained.

[0020] Furthermore, in the preparation method, the conductive anti-corrosion coating is removed by laser roughening.

[0021] Furthermore, in the preparation method, the cathode plate body further includes a second surface opposite to the first surface, and the anode plate body further includes a fourth surface opposite to the third surface;

[0022] Before hot pressing and laminating the cathode film in the first region, the method further includes:

[0023] Arrange a cooling chamber sealing strip on the second surface; or

[0024] Before the third region is hot-pressed and bonded with the anode film, the method further includes:

[0025] A cooling cavity sealing strip is provided on the fourth surface.

[0026] Furthermore, in the preparation method, the thickness of the cathode film is 0.01 to 0.05 mm; and / or

[0027] The thickness of the anode film is 0.01 to 0.05 mm.

[0028] Furthermore, in the preparation method, the shape of the cathode film is consistent with the first region; and / or

[0029] The shape of the anode film is consistent with that of the third region.

[0030] Furthermore, in the preparation method, the anode film and / or the cathode film is a thermoplastic or thermosetting material, and the curing temperature is ≤160°C.

[0031] Furthermore, in the preparation method, the temperature of the hot pressing bonding treatment is 80-140° C., the bonding pressure is 0.1-0.3 MPa, and the holding time is 5-30 s; and / or

[0032] In the hot pressing curing process, the heating temperature is controlled to be 100-150° C., the laminating pressure is controlled to be 0.1-0.3 MPa, and the holding time is controlled to be 5-30 seconds.

[0033] Furthermore, in the preparation method, after hot pressing and laminating the cathode film in the first region, the method further comprises:

[0034] Performing a roller-pressing and bubble-removing treatment on the cathode film;

[0035] After the anode film is laminated on the third region by hot pressing, the method further comprises:

[0036] The anode film is subjected to a roller pressing and bubble removal treatment.

[0037] The present application also proposes a fuel cell monomer, which is prepared by the above method.

[0038] The present application also proposes a fuel cell stack, comprising the above-mentioned fuel cell monomer.

[0039] The present application also proposes an electrical device, comprising the above-mentioned fuel cell stack, wherein the fuel cell stack serves as a power supply for the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is a flow chart of a method for preparing a fuel cell monomer provided in an embodiment of the present application;

[0041] Figure 2 This is an explosion effect diagram of a fuel cell unit in an embodiment of the present application;

[0042] Figure 3 This is a schematic structural diagram of the cathode plate body in an embodiment of the present application;

[0043] Figure 4 This is a schematic diagram of the structure of the membrane electrode in the embodiment of the present application;

[0044] Figure 5 This is a schematic structural diagram of the cooling chamber sealing strip in an embodiment of the present application;

[0045] Figure 6 This is a schematic diagram of the process of laminating the cathode film and the cathode plate;

[0046] Figure 7 This is a schematic diagram of the roller pressing process of the cathode film on the cathode plate. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects solved by this application more clearly understood, this application is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0048] The fuel cell is the core component of a proton exchange membrane fuel cell (PEMFC), responsible for the electrochemical reaction between hydrogen and oxygen to produce water and output electrical energy. The fuel cell design primarily utilizes a stacked structure of bipolar plates and a membrane electrode assembly (MEA), where the MEA includes a proton exchange membrane, a catalyst layer, and a gas diffusion layer.

[0049] The applicant found that the existing fuel cell monomers are sealed by screen printing, which is insufficient in micron-level thickness control, easily leading to uneven thickness of the integrated single cell, which in turn leads to uneven force in the assembly state, and ultimately leads to problems such as a decrease in the final contact conductivity and gas sealing of the single cell; in addition, after hot pressing, if the conventional integrated battery monomer is found to be airtight, it is extremely difficult to separate the various components and re-hot press them, resulting in a low pass rate for the preparation of integrated single cells.

[0050] Based on the above findings, the present invention provides a method for preparing a fuel cell monomer in order to solve the problem that the fuel cell monomer prepared by the existing method is prone to uneven thickness, resulting in airtight leakage and poor contact. Figure 1 As shown, it includes steps 101 to 105.

[0051] The fuel cell monomer in the embodiment of the present application is as follows Figure 2 As shown, it may include an anode plate body 10, an anode film 20, a membrane electrode 30, a cathode film 40, a cathode plate body 50 and a cooling chamber sealing strip 60 which are stacked in sequence.

[0052] Step 101: Provide a cathode plate body, wherein the cathode plate body includes a first surface, wherein the first surface includes a first region and a second region different from the first region, wherein the first region is used to seal with the cathode catalyst layer of the membrane electrode, and the second region is a cathode reaction region.

[0053] In this step, if Figure 3 As shown, the first surface of the cathode plate body 50 is the surface of the cathode plate body 50 used to form the cathode reaction chamber, the first area 51 is the area for bonding and sealing with the cathode catalyst layer of the membrane electrode 30, and the second area 52 serves as the cathode reaction area. The first area 51 needs to be arranged around the second area 52 to seal the cathode reaction area.

[0054] In this step, flow channels are designed in the cathode plate body to distribute oxygen and water. As the current collector on the cathode side, it is responsible for collecting current and evenly distributing external reaction gases (such as oxygen) to the cathode catalyst layer while discharging the generated water.

[0055] Step 102: hot-pressing and laminating a cathode film in the first region to form a cathode plate.

[0056] In this step, the cathode film is laminated to the first region by means of heat pressing, so as to become one with the cathode plate body, thereby obtaining the cathode plate.

[0057] Step 103: Provide an anode plate body, wherein the anode plate body includes a third surface, the third surface includes a third region and a fourth region different from the third region, the third region is used to seal with the anode catalyst layer of the membrane electrode, and the fourth region is the anode reaction region.

[0058] In this step, the third surface is the surface in the cathode plate body used to form the anode reaction chamber, the third area is the area for bonding and sealing with the anode catalyst layer of the membrane electrode, and the fourth area serves as the anode reaction area. The third area needs to be arranged around the fourth area to seal the anode reaction area.

[0059] In this step, flow channels are designed in the anode plate body to distribute hydrogen and water, which serves as the current collector on the anode side, responsible for collecting current and evenly distributing external reaction gases (such as hydrogen) to the anode catalyst layer.

[0060] Step 104 : hot-pressing and laminating the anode film in the third region to form an anode plate.

[0061] In this step, the anode film is laminated to the third region by means of hot pressing, so as to become one with the anode plate body, thereby obtaining the anode plate.

[0062] Step 105 : stack the anode plate, membrane electrode and cathode plate in sequence with the first surface facing the cathode catalyst layer and the third surface facing the anode catalyst layer, and then perform heat pressing and curing to form a fuel cell unit.

[0063] In this step, the membrane electrode is the core component of the fuel cell, responsible for realizing the hydrogen-oxygen reaction and converting it into electrical energy; the position of the membrane electrode in the structure of the battery cell is as follows: Figure 1 shown.

[0064] In this step, the membrane electrode 30 is a combination, such as Figure 4 As shown, the membrane electrode includes a reaction area 31 (usually including a cathode diffusion layer, a cathode catalyst layer, a proton exchange membrane, an anode catalyst layer and an anode diffusion layer) and a membrane electrode frame 32. There are usually no less than 6 through holes distributed on the membrane electrode frame 32 as a common manifold for fuel, air and coolant to pass through. At the same time, there are narrow through holes near the inlet and outlet of the fuel and air as guide manifolds, which are used to guide the fuel or air in the common manifold to the corresponding flow channel, or to guide the fuel or air in the flow channel to the common manifold.

[0065] Alternatively, as Figure 4 As shown, the common manifold includes a first common manifold 321, a second common manifold 322, a third common manifold 323, a fourth common manifold 324, a fifth common manifold 325, and a sixth common manifold 326, and the guide manifold includes a first air guide manifold 331, a second air guide manifold 332, a first fuel guide manifold 333, and a second guide manifold 334; wherein the first common manifold 321 and the sixth common manifold 326 are used for air to pass through, and the second common manifold 322 and the fifth common manifold 325 are used for fuel to pass through. The 5 pipes are used for passing coolant, the third common manifold 323 and the fourth common manifold 324 are used for passing fuel, the first common manifold 321 is provided with a first air guide manifold 331 at its inlet and outlet, the sixth common manifold 326 is provided with a second air guide manifold 332 at its inlet and outlet, the third common manifold 323 is provided with a first fuel guide manifold 333 at its inlet and outlet, and the fourth common manifold 324 is provided with a second fuel guide manifold 334 at its inlet and outlet. The path for the fuel to enter the reaction area can be as follows:

[0066] fuel→third common manifold 323→first fuel guide manifold 333→reaction area; or

[0067] Fuel → fourth common manifold 324 → second fuel flow manifold 334 → reaction area.

[0068] In this step, because the first area of ​​the first surface of the cathode plate is adhered with the cathode film, and the third area of ​​the third surface of the anode plate is adhered with the anode film, the anode plate, the membrane electrode and the cathode plate are stacked in sequence with the first surface facing the cathode catalyst layer and the third surface facing the anode catalyst layer, and the cathode film is aligned with the membrane electrode frame on the cathode catalyst layer side, and the anode film is aligned with the membrane electrode frame on the anode catalyst layer side, and then hot-pressed and cured. The cathode film can be used to seal and buffer between the cathode plate body and the cathode catalyst layer, effectively preventing gas leakage on the cathode side, and the anode film can be used to seal and buffer between the anode plate body and the anode catalyst layer, effectively preventing gas leakage on the anode side.

[0069] In the preparation method provided in the embodiment of the present application, the cathode plate, membrane electrode and anode plate are combined into one by step-by-step hot pressing and bonding through the cathode film and the anode film. The thickness of the sealing area of ​​the integrated battery cell can reach the micron level through simple molds and process control, which can effectively improve the problems of airtight leakage and poor contact caused by uneven thickness, thereby improving the qualified rate of the integrated preparation of battery cells, being more conducive to the consistency of the fuel cell stack assembly, and effectively reducing the weight and thickness of the single cell.

[0070] Optionally, in one embodiment, the first region and the third region are exposed, and the surfaces of the second region and the fourth region have a conductive anti-corrosion coating.

[0071] In this embodiment, before hot pressing to form the cathode / anode plates, the first / third regions of the cathode / anode plate body used for sealing with the cathode / anode catalyst layer of the membrane electrode are controlled to be exposed, that is, no conductive anti-corrosion coating is provided. This can increase the surface roughness of the cathode / anode plate body, thereby increasing the bonding strength with the cathode / anode film while ensuring the conductive anti-corrosion performance, and further improving the airtightness of the battery cell.

[0072] In this embodiment, the surfaces of the second region and the fourth region have a conductive anti-corrosion coating, which can effectively enhance the corrosion resistance of the cathode plate and the anode plate and extend the service life of the battery.

[0073] In this embodiment, the conductive anti-corrosion coating may be made of any corrosion-resistant material with conductive properties in the prior art.

[0074] Optionally, in one embodiment, a cathode plate body is provided, comprising:

[0075] The first surface of the stamped cathode plate body is shielded in a first area, and then a conductive anti-corrosion coating is plated in the second area.

[0076] In this embodiment, the cathode plate body after stamping is partially shielded in the first area and then coated, but the function of the reaction area in the second area is not affected. A conductive anti-corrosion coating can be formed only in the second area, while the cathode plate body in the first area remains exposed.

[0077] Alternatively, in another embodiment, a cathode plate body is provided, comprising:

[0078] The first surface of the stamped cathode plate body is plated with a conductive anti-corrosion coating, and then the conductive anti-corrosion coating in the first area of ​​the first surface is removed, while the conductive anti-corrosion coating in the second area is retained.

[0079] In this embodiment, the entire first surface of the cathode plate body after stamping is plated to form a conductive anti-corrosion coating, and then the conductive anti-corrosion coating in the first area is removed specifically, while the conductive anti-corrosion coating in the second area is retained, that is, the first area is exposed and the second area has a conductive anti-corrosion coating.

[0080] Optionally, in one embodiment, an anode plate body is provided, comprising:

[0081] The third surface of the stamped anode plate body is shielded in a third area, and then a conductive anti-corrosion coating is plated in the fourth area.

[0082] In this embodiment, the third region of the stamped anode plate body is partially shielded and then coated, but the function of the fourth region reaction area is not affected. A conductive anti-corrosion coating can be formed only in the fourth region, while the third region remains exposed.

[0083] Optionally, in another embodiment, an anode plate body is provided, comprising: plating a conductive anti-corrosion coating on the third surface of the stamped anode plate body, removing the conductive anti-corrosion coating in the third area of ​​the third surface, and retaining the conductive anti-corrosion coating in the fourth area.

[0084] In this embodiment, the entire third surface of the stamped anode plate body is plated to form a conductive anti-corrosion coating, and then the conductive anti-corrosion coating in the third area is removed in a targeted manner, while the conductive anti-corrosion coating in the fourth area is retained, that is, the third area is exposed and the fourth area has a conductive anti-corrosion coating.

[0085] Optionally, in one embodiment, the conductive anti-corrosion coating is removed by laser roughening, which can quickly and accurately process the first area / third area into a roughened state. The surface thickness of the laser roughening layer is approximately 50 to 1000 nm, ensuring that the coating layer on the surface of the first area / third area is removed and that the underlying metal substrate in the corresponding area is exposed, thereby facilitating bonding with the adhesive film in subsequent steps.

[0086] Optionally, in some embodiments, the surface roughness of the substrate in the laser-textured area is Ra≥0.4, which can effectively increase the bonding strength with the adhesive film, thereby improving the airtightness of the battery cell.

[0087] In the embodiment of the present application, the cathode plate body and the anode plate body may be made of metal materials to ensure electrical conductivity.

[0088] Optionally, in one embodiment, the cathode plate body further includes a second surface opposite to the first surface;

[0089] Before hot pressing and laminating the cathode film in the first region, the method further includes:

[0090] A cooling chamber sealing strip is provided on the second surface.

[0091] In this embodiment, the cooling cavity sealing strip is used to form a cooling cavity on the surface of the battery cell for the passage of coolant; the cooling cavity sealing strip is set on the second surface of the cathode plate body, and then the two adjacent battery cells are stacked and assembled into a battery stack through the cooling cavity sealing strip, that is, a cooling cavity can be formed between the two adjacent battery cells, isolating the cooling cavity liquid from leaking out, the anode cavity gas from entering the cooling cavity, and the cathode cavity gas from entering the cooling cavity, thereby cooling the battery cell through the coolant in the cooling cavity.

[0092] In some embodiments, the cooling chamber sealing strip can be connected to the cathode plate as a whole by injection molding, transfer printing, or gluing.

[0093] Optionally, in another embodiment, the anode plate body further includes a fourth surface opposite to the third surface;

[0094] Before the third region is hot-pressed and bonded with the anode film, the method further includes:

[0095] A cooling cavity sealing strip is provided on the fourth surface.

[0096] In this embodiment, the cooling cavity sealing strip is used to form a cooling cavity on the surface of the battery cell for the passage of coolant; the cooling cavity sealing strip is set on the fourth surface of the anode plate body, and then the two adjacent battery cells are assembled into a battery stack through the cooling cavity sealing strip, that is, a cooling cavity can be formed between the two adjacent battery cells, isolating the cooling cavity liquid from leaking out, the anode cavity gas from entering the cooling cavity, and the cathode cavity gas from entering the cooling cavity, thereby cooling the battery cell through the coolant in the cooling cavity.

[0097] In some embodiments, the cooling chamber sealing strip may be integrally connected to the anode plate by injection molding, transfer printing, or adhesive bonding.

[0098] In the embodiment of this application, Figure 5 As shown, the cooling chamber sealing strips 60 can be connected together in a strip shape or an island shape, and their cross-sections can be rectangular, trapezoidal, elliptical or anisotropic.

[0099] Optionally, in one embodiment, after the cathode film is hot-pressed and laminated to the first region, the preparation method provided in the embodiment of the present application further comprises:

[0100] The cathode film is subjected to a roller pressing and bubble removal treatment.

[0101] In this embodiment, after the cathode film is attached to the first area of ​​the cathode plate body, the surface of the cathode film in the first area is rolled and de-bubbled using a roller or other means to eliminate bubbles and other defects during the attachment process, thereby ensuring the sealing and overall structural stability of the fuel cell unit.

[0102] Optionally, the qualified standard for roller debubbling treatment is: bubble diameter ≤0.3mm and bubble number ≤10 per square centimeter; that is, when the roller debubbling treatment reaches bubble diameter ≤0.3mm and bubble number ≤10 per square centimeter, the roller debubbling treatment is terminated, otherwise the roller debubbling is continued until the above standards are met.

[0103] Optionally, in one embodiment, the thickness of the cathode film may be 0.01 to 0.05 mm, which can effectively seal and buffer between the cathode plate and the membrane electrode to prevent gas leakage.

[0104] In some embodiments, the thickness of the cathode film may be within the range of one or any two of 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, and 0.05 mm.

[0105] In some embodiments, the shape of the cathode film is consistent with that of the first region, which can not only effectively perform sealing and buffering functions, but also enable the coolant to have a larger contact area with the battery cell, thereby achieving a better cooling effect.

[0106] In some embodiments, laminating a cathode film in the first region includes:

[0107] like Figure 6 As shown, the sheet film is adsorbed onto the first tooling 61, and the film shape required for the first region 51 is cut out by laser or die cutting to form the cathode film 40. The light release film I on the surface A of the cathode film is removed, while the heavy release film II on the other surface B is retained. The second surface (cathode plate side cooling cavity) of the cathode plate body is vacuum-adsorbed, and the cathode plate body 50 is positionally matched with the first tooling 61 using a limit device or visual limiter. The air cavity surface of the cathode plate is bonded to the surface A of the cathode film, and the two are heated and bonded using the base of the first tooling 61.

[0108] like Figure 7 As shown, the cathode plate body 50 after bonding is turned over and placed on the second tooling 62. The second tooling 62 is provided with an air-avoiding design that matches the second surface of the cathode plate body 50. The roller 63 is then used to roll and remove bubbles on the surface B of the cathode film in the first area 51, and then the heavy release film II on the surface B is peeled off.

[0109] In this embodiment, the air-avoidance design can avoid the first area (ie, the sealing area at the cathode plate) and the second area (ie, the reaction area at the cathode plate).

[0110] Optionally, in one embodiment, after the anode film is hot-pressed and laminated in the third region, the preparation method provided in the embodiment of the present application further includes:

[0111] The anode film is subjected to a roller pressing and bubble removal treatment.

[0112] In this embodiment, after the cathode film is bonded to the third area of ​​the anode plate body, the surface of the rear electrode film in the third area is rolled and de-bubbled using a roller or other means to eliminate bubbles and other defects during the bonding process, thereby ensuring the sealing and overall structural stability of the fuel cell unit.

[0113] Optionally, in one embodiment, the thickness of the anode film may be 0.01 to 0.05 mm, which can effectively play a sealing and buffering role between the anode plate and the membrane electrode to prevent gas leakage.

[0114] In some embodiments, the thickness of the anode film may be within the range of one or any two of 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, and 0.05 mm.

[0115] In some embodiments, the shape of the anode film is consistent with the third region, which can not only effectively play a sealing and buffering role, but also enable the coolant and the battery cell to have a larger contact area, thereby achieving a better cooling effect.

[0116] Optionally, in one embodiment, the anode film and the cathode film are made of thermoplastic or thermosetting materials with a curing temperature of ≤160°C, and can be hot-pressed into one without damaging the cathode plate, anode plate and membrane electrode.

[0117] The thermoplastic material may be a reactive polyurethane hot melt adhesive such as DOCBOND DB9664, or a modified polyolefin such as polypropylene, polyvinyl chloride, polystyrene, and the like.

[0118] The thermosetting material may be epoxy resin glue, organic silicone glue, etc.

[0119] Optionally, in a specific embodiment, the temperature of the hot pressing bonding treatment is 80-140°C, the bonding pressure is 0.1-0.3 MPa, and the holding time is 5-30s, so that the cathode film can be tightly bonded to the above-mentioned first area, and the anode film can be tightly bonded to the above-mentioned third area.

[0120] In some embodiments, the temperature of the hot pressing bonding treatment can be one of 80°C, 90°C, 100°C, 110°C, 120°C, 130°C, 140°C or any two of the range values, the bonding pressure can be one of 0.1 MPa, 0.2 MPa, 0.3 MPa or any two of the range values, and the holding time can be one of 5s, 6s, 8s, 10s, 15s, 20s, 30s or any two of the range values.

[0121] Optionally, in a specific embodiment, in the above-mentioned hot pressing curing treatment, the heating temperature is controlled to be 100-150°C, the bonding pressure is 0.1-0.3 MPa, and the holding time is 5-30s. The cathode film and the anode film can be used to tightly bond the cathode plate to one side of the cathode catalyst layer in the membrane electrode, and the anode plate to one side of the anode catalyst layer in the membrane electrode, thereby integrating the anode plate, the membrane electrode and the cathode plate into a fuel cell monomer.

[0122] In some embodiments, the temperature of the hot pressing curing treatment can be one of 100°C, 110°C, 120°C, 130°C, 140°C, 150°C or any two of the range values, the bonding pressure can be one of 0.1MPa, 0.2MPa, 0.3MPa or any two of the range values, and the holding time can be one of 5s, 6s, 8s, 10s, 15s, 20s, 30s or any two of the range values.

[0123] In some embodiments, laminating an anode film to the third region includes:

[0124] The sheet film is adsorbed onto the third tooling, and the film shape required in the third area is cut by laser or die cutting to serve as the anode film. The lightweight release film I on the surface A of the anode film is removed, and the heavy release film II on the other surface B is retained. The fourth surface (the cooling cavity on the anode plate side) of the anode plate body is adsorbed by vacuum, and the anode plate body is positionally matched with the third tooling using a limit device or visual limiter. The air cavity surface of the cathode plate is bonded to the surface A of the cathode film, and the two are heated and bonded using the third tooling base;

[0125] The cathode plate body after bonding is turned over and placed on the fourth tooling. The fourth tooling is provided with an air avoidance design that matches the second surface of the anode plate body. The surface of the anode film B in the third area is then rolled and de-bubbled using a roller, and then the heavy release film II on the B surface is peeled off.

[0126] In this embodiment, the air-avoidance design can avoid the third area (ie, the sealing area at the anode plate) and the fourth area (ie, the reaction area at the anode plate).

[0127] The present application also proposes a fuel cell monomer, which is prepared by the above method.

[0128] The fuel cell monomer generates electricity and water through a chemical reaction between hydrogen (or other fuel) and an oxidant (such as oxygen) on the MEA. The following is the specific process:

[0129] (a) Gas supply:

[0130] The fuel gas (such as compressed hydrogen) passes through the common manifold, then enters the anode plate through the guide manifold on the membrane electrode frame in the battery cell, and is finally evenly distributed to the anode side of the membrane electrode by the flow channel in the anode plate;

[0131] The oxidant gas (such as air or pure oxygen) passes through the common manifold, then enters the cathode plate through the guide manifold on the membrane electrode frame in the battery cell, and is finally evenly distributed to the cathode side of the membrane electrode by the flow channel in the cathode plate.

[0132] (b) Electrochemical reaction:

[0133] Anode reaction: The fuel gas is oxidized by the catalyst, releasing protons and electrons. The protons diffuse through the electrolyte layer to the cathode, while the electrons flow through the external circuit to form an electric current.

[0134] Cathode reaction: Oxygen combines with protons and electrons to produce water (H2O) and exit the system.

[0135] (c) Power output:

[0136] The electrical energy generated by the battery cells is used by an external load such as an electric motor, electronic device or the power grid.

[0137] The present application also proposes a fuel cell stack, comprising the above-mentioned fuel cell monomer.

[0138] Among them, the fuel cell stack can repeatedly stack different numbers of the above-mentioned fuel cell monomers according to the power requirements of the stack, and compress and fix them under a certain stacking pressure to ensure the reduction of contact resistance and sealing consistency between the battery cells and between different components inside the battery cells.

[0139] Multiple fuel cell units in a fuel cell stack can be connected in series or in parallel to form a larger fuel cell stack to meet higher power requirements.

[0140] The present invention also proposes an electrical device, which includes the above-mentioned fuel cell stack, and the fuel cell stack serves as a power supply for the electrical device.

[0141] For the above-mentioned fuel cell stack and electrical equipment embodiments, they include the above-mentioned fuel cell monomers, and the fuel cell monomers are prepared by the above-mentioned preparation method and can achieve the same technical effects. To avoid repetition, they will not be described here. For relevant matters, please refer to the partial description of the method embodiment.

[0142] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention is further described below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention.

[0143] The present invention is described in detail below by way of examples.

[0144] Example 1

[0145] (1) Preparation of cathode plate body

[0146] A graphite-like coating is coated on the first surface of the cathode plate body after stamping as a conductive anti-corrosion coating, and then the conductive anti-corrosion coating in the first area of ​​the first surface is removed by laser roughening, while the conductive anti-corrosion coating in the second area is retained; and then a cooling chamber sealing strip is injection molded on the second surface of the cathode plate body.

[0147] (2) Preparation of cathode plate

[0148] Adsorb a 0.04mm thick epoxy resin-based thermosetting adhesive film sheet onto the first tooling, laser or die cut the required film shape in the first area as the cathode film, remove the lightweight release film I on the surface A of the cathode film, and retain the heavy release film II on the other surface B. Vacuum adsorb the second surface of the cathode plate body (cathode plate side cooling cavity) and use a limit device to limit and match the cathode plate body with the first tooling, and laminate the air cavity surface of the cathode plate with the surface of the cathode film A. The first tooling base is used to heat and laminate the two at a temperature of 100°C, a laminating pressure of 0.2MPa, and a holding time of 15s.

[0149] The cathode plate body after bonding is turned over and placed on the second tooling. The second tooling is provided with an air avoidance design that matches the second surface of the cathode plate body. The surface of the cathode film B in the first area is then rolled and de-bubbled using a roller, and the heavy release film II on the B surface is then peeled off to obtain the cathode plate.

[0150] (3) Preparation of anode plate

[0151] The third surface of the stamped anode plate body is plated with a conductive anti-corrosion coating, the conductive anti-corrosion coating in the third area of ​​the third surface is removed, and the conductive anti-corrosion coating in the fourth area is retained.

[0152] (4) Preparation of anode plate

[0153] The sheet film is adsorbed on the third tooling, and the film shape required in the third area is cut by laser or die cutting as the anode film. The lightweight release film I on the surface A of the anode film is removed, and the heavy release film II on the other surface B is retained. The fourth surface (anode plate side cooling cavity) of the anode plate body is adsorbed by vacuum and the anode plate body is limited and matched with the third tooling by a limiting device. The air cavity surface of the cathode plate is bonded to the surface of the cathode film A, and the two are heated and bonded using the third tooling base at a temperature of 100°C, a bonding pressure of 0.2 MPa, and a holding time of 15 seconds.

[0154] The cathode plate body after bonding is turned over and placed on the fourth tooling. The fourth tooling is provided with an air avoidance design that matches the second surface of the anode plate body. The surface of the anode film B in the third area is then rolled and de-bubbled using a roller, and the heavy release film II on the B surface is then peeled off to obtain the anode plate.

[0155] (5) Preparation of battery cells

[0156] The anode plate, membrane electrode and cathode plate are stacked in order and then hot-pressed and cured at a heating temperature of 120°C, a bonding pressure of 0.2 MPa and a holding time of 15 seconds to form a fuel cell monomer.

[0157] 1000 fuel cell monomers were prepared using the above embodiment. The results showed that airtightness problems accounted for 3%, poor contact accounted for 0.5%, and the qualified rate was 96.5%.

[0158] To sum up, in the preparation method provided in the embodiment of the present application, the cathode plate, membrane electrode and anode plate are combined into one by step-by-step hot pressing and bonding through the cathode film and the anode film. The two sets of tooling can effectively control the molding thickness of the final single cell, so that the thickness of the sealing area of ​​the integrated battery cell reaches the micron level, which can effectively improve the problems of airtight leakage and poor contact caused by uneven thickness, thereby improving the qualified rate of integrated preparation of battery cells, which is more conducive to the consistency of fuel cell stack assembly, and effectively reduces the weight and thickness of the single cell.

[0159] Terminology

[0160] In this application, a plurality refers to two or more.

[0161] The terms "first," "second," "third," "fourth," etc. (if any) in this application are used to distinguish similar objects and are not necessarily used to describe a particular sequential order.

[0162] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0163] Unless otherwise specified, all steps of the present application may be performed sequentially or randomly. For example, a statement that the method includes steps A and B indicates that the method may include steps A and B performed sequentially, or steps B and A performed sequentially. For example, a statement that the method may also include step C indicates that step C may be added to the method in any order, for example, the method may include steps A, B, and C, or steps A, C, and B, or steps C, A, and B, etc.

[0164] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present application should be included in the scope of protection of the present application.

Claims

1. A method for preparing a fuel cell monomer, characterized in that: include: Providing a cathode plate body, the cathode plate body comprising a first surface, the first surface comprising a first region and a second region different from the first region, the first region being used to seal with the cathode catalyst layer of the membrane electrode, and the second region being a cathode reaction region; Hot pressing and laminating a cathode film in the first region to form a cathode plate; Providing an anode plate body, the anode plate body comprising a third surface, the third surface comprising a third region and a fourth region different from the third region, the third region being used to seal with the anode catalyst layer of the membrane electrode, and the fourth region being an anode reaction region; Hot pressing and laminating an anode film in the third region to form an anode plate; The anode plate, membrane electrode and cathode plate are stacked in sequence with the first surface facing the cathode catalyst layer and the third surface facing the anode catalyst layer, and then heat-pressed and cured to form a fuel cell monomer.

2. The preparation method according to claim 1, characterized in that A cathode plate body is provided, comprising: The first surface of the cathode plate body after stamping is shielded in a first area, and then the second area is plated with a conductive anti-corrosion coating; or Plating a conductive anti-corrosion coating on the first surface of the stamped cathode plate body, then removing the conductive anti-corrosion coating in a first area of ​​the first surface, and retaining the conductive anti-corrosion coating in a second area; Provide anode plate body, including: The third surface of the stamped anode plate body is shielded in a third area, and then a conductive anti-corrosion coating is plated in the fourth area; or The third surface of the stamped anode plate body is plated with a conductive anti-corrosion coating, the conductive anti-corrosion coating in the third area of ​​the third surface is removed, and the conductive anti-corrosion coating in the fourth area is retained.

3. The preparation method according to claim 2, characterized in that The conductive anti-corrosion coating is removed by laser roughening.

4. The preparation method according to claim 1, characterized in that The cathode plate body further includes a second surface opposite to the first surface, and the anode plate body further includes a fourth surface opposite to the third surface; Before hot pressing and laminating the cathode film in the first region, the method further includes: Arrange a cooling chamber sealing strip on the second surface; and / or Before the third region is hot-pressed and bonded with the anode film, the method further includes: A cooling cavity sealing strip is provided on the fourth surface.

5. The preparation method according to claim 1, characterized in that The thickness of the cathode film is 0.01 to 0.05 mm; and / or The thickness of the anode film is 0.01 to 0.05 mm.

6. The preparation method according to claim 1, characterized in that The shape of the cathode film is consistent with that of the first region; and / or The shape of the anode film is consistent with that of the third region.

7. The preparation method according to claim 1, characterized in that The anode film and / or the cathode film is made of thermoplastic or thermosetting material, and the curing temperature is ≤160°C.

8. The preparation method according to claim 7, characterized in that The temperature of the hot pressing lamination process is 80-140° C., the lamination pressure is 0.1-0.3 MPa, and the holding time is 5-30 seconds; and / or In the hot pressing curing process, the heating temperature is controlled to be 100-150° C., the laminating pressure is controlled to be 0.1-0.3 MPa, and the holding time is controlled to be 5-30 seconds.

9. The preparation method according to any one of claims 1 to 8, characterized in that After the cathode film is laminated to the first region by hot pressing, the method further includes: Performing a roller-pressing and bubble-removing treatment on the cathode film; After the anode film is laminated on the third region by hot pressing, the method further comprises: The anode film is subjected to a roller pressing and bubble removal treatment.

10. A fuel cell monomer, characterized in that: The method is prepared by any one of claims 1 to 9.

11. A fuel cell stack, characterized in that: The fuel cell unit comprises the fuel cell unit as claimed in claim 10.

12. An electrical device, characterized in that: The fuel cell stack as claimed in claim 11 is used as a power supply for the electrical equipment.

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