Air-cooled hydrogen fuel cell bipolar plate, single cell and electric pile
By designing a sunken groove structure for the bipolar plate of an air-cooled hydrogen fuel cell, the problems of numerous components and large frame thickness were solved, achieving efficient heat transfer and improved battery performance, while reducing manufacturing costs and system complexity.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- QINGDAO CHUANGQI XINDE NEW ENERGY TECH CO LTD
- Filing Date
- 2025-05-15
- Publication Date
- 2026-04-24
AI Technical Summary
Existing air-cooled membrane electrode assemblies have many components, complex packaging, and large frame thickness, which affects the heat transfer efficiency and lifespan of hydrogen fuel cells, and also poses the problem of gas diffusion layer overpressure.
A bipolar plate for an air-cooled hydrogen fuel cell is designed, which uses a sunken groove structure to arrange the anode and cathode channels, and adjusts the compression of the gas diffusion layer by controlling the groove depth to reduce the number of components and assembly steps, and uses a single-sided membrane electrode structure.
It improves the diffusion rate and uniformity of hydrogen and oxygen, reduces the frame thickness, improves the heat transfer efficiency and lifespan of the battery, and reduces manufacturing costs and system complexity.
Smart Images
Figure CN224164220U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of air-cooled hydrogen fuel cell technology, specifically to an air-cooled hydrogen fuel cell bipolar plate, single cell, and stack. Background Technology
[0002] Hydrogen fuel cells are a clean energy technology that converts the electrochemical reaction of hydrogen and oxygen into electricity, with water vapor being the only emission. Promoting hydrogen energy technology can facilitate the use of renewable energy, reduce dependence on traditional energy sources, and thus lessen environmental pressure. Furthermore, compared to traditional combustion power generation and internal combustion engine systems, hydrogen fuel cells offer high energy conversion efficiency.
[0003] The membrane electrode assembly (MEA) of a hydrogen fuel cell is a key component. Continuous improvement of the MEA can enhance the efficiency, stability, and lifespan of hydrogen fuel cells, promoting their application in renewable and clean energy sectors. Water-cooled stack MEAs require an additional water-cooling system, including water pumps and coolers, increasing system complexity, cost, and the difficulty of operation and maintenance. Furthermore, water-cooled stacks pose a risk of water leakage, which could damage equipment or create safety hazards. Air-cooled stack MEAs, on the other hand, avoid these drawbacks of water-cooled stacks, offering greater flexibility and applicability.
[0004] Current air-cooled reactor membrane electrode assemblies (MEAs), such as the seven-in-one MEA, have many components and a complex encapsulation process, requiring specialized equipment and technology, which restricts the large-scale production of MEAs. Moreover, the existing air-cooled reactor MEAs have relatively thick frames, which affects the heat transfer efficiency of hydrogen fuel cells; the carbon paper in existing air-cooled reactor MEAs also suffers from overpressure issues, and when combined with the thick frames, the overall efficiency and lifespan of hydrogen fuel cells are affected. Utility Model Content
[0005] Based on the above-mentioned technical problems, this utility model proposes an air-cooled hydrogen fuel cell bipolar plate, a single cell, and a stack.
[0006] The technical solution adopted by this utility model is:
[0007] A bipolar plate for an air-cooled hydrogen fuel cell includes a plate body, a first groove on one side of the plate body in which a cathode channel is arranged, a second groove on the other side of the plate body in which an anode channel is arranged, and an air inlet and an air outlet at both ends of the plate body, which are respectively connected to the two ends of the anode channel.
[0008] Preferably, the cathode flow channel is a parallel flow channel; the anode flow channel is a serpentine flow channel.
[0009] Preferably, the plate is rectangular, the arrangement direction of the parallel flow channels is perpendicular to the extension direction of the plate, and the main flow direction of the serpentine flow channel is consistent with the extension direction of the plate.
[0010] Preferably, the serpentine flow channel is provided in several groups, and the main body of each group of serpentine flow channels occupies a certain area of the second groove.
[0011] Preferably, a sealing groove is provided around the periphery of the second groove.
[0012] Preferably, the groove depth of the first groove is 110-170μm, more preferably 120-160μm, and the height of the cathode flow channel is less than the groove depth of the first groove; the groove depth of the second groove is 100-160μm, more preferably 110-150μm, and the height of the anode flow channel is less than the groove depth of the second groove.
[0013] A single cell employs a bipolar plate as described above, specifically including a CCM membrane electrode, a membrane electrode frame, a first gas diffusion layer, and a second gas diffusion layer. A rectangular opening adapted to the CCM membrane electrode is provided at the center of the membrane electrode frame. The CCM membrane electrode is fixed on the membrane electrode frame, the first gas diffusion layer is bonded to one side of the CCM membrane electrode, and the second gas diffusion layer is bonded to the other side of the CCM membrane electrode. One bipolar plate is disposed on one side of the membrane electrode frame, and after pressing, the first gas diffusion layer is located in the first groove of the bipolar plate. The other bipolar plate is disposed on the other side of the membrane electrode frame, and after pressing, the second gas diffusion layer is located in the second groove of the bipolar plate.
[0014] Preferably, both the first gas diffusion layer and the second gas diffusion layer are made of carbon paper, with a carbon paper thickness of 150-260 μm, more preferably 180-250 μm, and a compression amount of 15-40%, more preferably 20-35%.
[0015] A fuel cell stack, which employs a plurality of single cells stacked as described above, with adjacent single cells sharing a single bipolar plate.
[0016] The beneficial technical effects of this utility model are as follows:
[0017] (1) The anode and cathode channels of the integrated air-cooled bipolar plate described in this utility model are both set in a sunken groove, and the compression of the gas diffusion layer is controlled according to the groove depth. This structure can effectively prevent the problem of overpressure of the gas diffusion layer in traditional membrane batteries, thereby improving the diffusion rate and uniformity of hydrogen and oxygen between membrane electrodes, and thus improving the response speed and output performance of single-frame membrane electrodes.
[0018] (2) The membrane electrode frame of this invention does not need to be used to prevent overpressure of the gas diffusion layer, so the thickness of the frame can be greatly reduced compared to traditional membrane electrodes. The thinner frame can transfer heat more effectively during fuel cell operation, improve the efficiency and life of the fuel cell, and help reduce manufacturing costs, improve production efficiency and processing accuracy.
[0019] (3) The membrane electrode structure of this utility model only requires a single frame, combined with the bipolar plate of the above structure, which reduces the number of components and assembly steps, and lowers the manufacturing cost. Moreover, it effectively reduces electrode voltage drop and gas diffusion resistance, improving battery performance and efficiency. This structure also reduces the contact resistance between the frames, improving the battery's conductivity.
[0020] (4) The integrated air-cooled reactor described in this utility model does not require mold casting, which greatly reduces the manufacturing cost. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of one side of the bipolar plate of the air-cooled hydrogen fuel cell of this utility model;
[0022] Figure 2 This is a schematic diagram of the other side of the bipolar plate of the air-cooled hydrogen fuel cell of this utility model;
[0023] Figure 3 This is an exploded view of the structure of the air-cooled hydrogen fuel cell of this utility model.
[0024] In the figure: 1-plate, 2-first groove, 3-cathode channel, 4-second groove, 5-anode channel, 6-air inlet, 7-air outlet, 8-sealing groove, 9-CCM membrane electrode, 10-membrane electrode frame, 11-first gas diffusion layer, 12-second gas diffusion layer, 13-rectangular opening;
[0025] 501 - First serpentine flow channel, 502 - Second serpentine flow channel, 503 - Third serpentine flow channel. Detailed Implementation
[0026] like Figure 1-2 As shown, an air-cooled hydrogen fuel cell bipolar plate includes a plate body 1. A first groove 2 is provided on one side of the plate body 1, and a cathode flow channel 3 is arranged in the first groove 2. A second groove 4 is provided on the other side of the plate body 1, and an anode flow channel 5 is arranged in the second groove 4. An air inlet 6 and an air outlet 7 are respectively provided at both ends of the plate body 1, and the air inlet 6 and the air outlet 7 are respectively connected to the two ends of the anode flow channel 5.
[0027] The cathode channel 3 described above adopts a parallel flow channel; the anode channel 5 adopts a serpentine flow channel. Specifically, the plate 1 is rectangular, and the arrangement direction of the parallel flow channels is perpendicular to the extension direction of the plate 1. The main flow direction of the serpentine flow channel is consistent with the extension direction of the plate. More specifically, several groups of serpentine flow channels are provided, and the main body of each group of serpentine flow channels occupies a certain area of the second groove 4. For example... Figure 2 As shown, the serpentine flow channel is provided in three sets, namely the first serpentine flow channel 501 and the second serpentine flow channel 502 located at both ends of the second groove 4, and the third serpentine flow channel 503 located in the middle of the second groove 4.
[0028] A sealing groove 8 is also provided around the second groove 4. A sealing element can be placed in the sealing groove 8 to seal during pressing and prevent gas leakage through the anode channel 5.
[0029] The groove depth of the first groove 2 is 120-160 μm, and the groove depth of the second groove 4 is 110-150 μm. The height of the cathode channel 3 is less than the groove depth of the first groove 2, and the height of the anode channel 5 is less than the groove depth of the second groove 4. The difference between the channel height and the groove depth is used for the subsequent pressing of the gas diffusion layer.
[0030] In the aforementioned air-cooled hydrogen fuel cell bipolar plate, hydrogen enters through the inlet 6, flows through the anode channel 5, and exits through the outlet. Air is drawn in from the outside and flows along the parallel channel, i.e., the cathode channel 3. This achieves the separate flow distribution of hydrogen and air on both sides of the CCM membrane electrode.
[0031] This membrane electrode is suitable for proton exchange membrane (PEM) fuel cells and can solve the problem of difficulty in controlling the compression of single-sided membrane electrodes while reducing system complexity and cost.
[0032] The bipolar plate flow channel area is grooved, and the carbon paper compression is controlled by the groove depth. The membrane electrode frame does not need to control the carbon paper compression, so the thickness of the membrane electrode frame is much lower than that of a normal frame.
[0033] like Figure 3As shown, a single cell employs the bipolar plate described above, specifically including a CCM membrane electrode 9, a membrane electrode frame 10, a first gas diffusion layer 11, and a second gas diffusion layer 12. A rectangular opening 13 adapted to the CCM membrane electrode 9 is provided at the center of the membrane electrode frame 10. The CCM membrane electrode 9 is fixed to the membrane electrode frame 10, the first gas diffusion layer 11 is bonded to one side of the CCM membrane electrode 9, and the second gas diffusion layer 12 is bonded to the other side of the CCM membrane electrode 9. One bipolar plate is disposed on one side of the membrane electrode frame 10, and after pressing, the first gas diffusion layer 11 is located in the first groove 2 of the bipolar plate. The other bipolar plate is disposed on the other side of the membrane electrode frame 10, and after pressing, the second gas diffusion layer 12 is located in the second groove 4 of the bipolar plate.
[0034] Both the first gas diffusion layer 11 and the second gas diffusion layer 12 are made of carbon paper with a thickness of 180-250 μm and a compression of 20-35%.
[0035] This utility model also provides a fuel cell stack, which uses several single cells stacked as described above, with adjacent single cells sharing a single bipolar plate.
[0036] The method for preparing the fuel cell stack as described above includes the following steps:
[0037] (1) A cathode catalytic layer and an anode catalytic layer are coated on both sides of the proton exchange membrane to obtain a CCM membrane electrode.
[0038] (2) The anode catalyst layer of the CCM membrane electrode overlaps with the rectangular opening area in the center of the membrane electrode frame, and the membrane electrode frame is directly bonded to the proton exchange membrane of the CCM membrane electrode.
[0039] (3) The bipolar plate is formed by integrated stamping. After etching and grooving, the cathode flow channel and anode flow channel are machined by CNC cutting.
[0040] (4) A first gas diffusion layer is placed between the membrane electrode frame and the second groove of one of the bipolar plates, and the first gas diffusion layer is bonded to the membrane electrode frame; a second gas diffusion layer is placed between the CCM membrane electrode and the first groove of the other bipolar plate, and the second gas diffusion layer is bonded to the CCM membrane electrode.
[0041] (5) Press the two bipolar plates together with the first gas diffusion layer, the membrane electrode frame, the CCM membrane electrode and the second gas diffusion layer between them to assemble a single cell.
[0042] (6) Several single cells are stacked one on top of the other, and adjacent single cells share a bipolar plate to form an air-cooled hydrogen fuel cell stack.
[0043] In summary, this invention provides a high-efficiency air-cooled hydrogen fuel cell stack. The integrated air-cooled hydrogen fuel cell bipolar plate includes an anode flow channel and a cathode flow channel. The flow field adopts a sunken groove design, with gas flow channels on the surface of the groove area. A gas diffusion layer, such as carbon paper, can be placed inside the groove. The anode flow channel where the carbon paper is placed is bonded to the single-frame membrane electrode assembly; the cathode flow channel area, after placing the carbon paper, is bonded to the integrated single-frame membrane electrode assembly. The groove depth of the anode and cathode plates is consistent with the thickness of the carbon paper after optimal compression, which can effectively prevent overpressure. The single-frame integrated membrane electrode assembly structure design proposed in this invention can significantly reduce the stack thickness, save costs, and ensure that the stack achieves optimal performance.
[0044] In this novel fuel cell stack, only the membrane electrode anode has a membrane electrode frame, and the thickness of the membrane electrode frame is less than that of a conventional frame. The central rectangular area of the membrane electrode frame overlaps with the anode catalyst layer, and the membrane electrode frame is directly bonded to the proton exchange membrane anode using an adhesive.
[0045] In the preparation method, the carbon paper can be further hydrophilicated. For example, it can be treated with anhydrous ethanol, ammonia, formaldehyde, and tetraethyl orthosilicate solution for 24 hours, and then the carbon paper can be surface modified with concentrated nitric acid to finally obtain carbon paper with good hydrophilicity. The first gas diffusion layer 11 is bonded to the anode catalyst layer of the CCM membrane electrode by an adhesive, and the second gas diffusion layer 12 is bonded to the cathode catalyst layer of the CCM membrane electrode by an adhesive.
[0046] Furthermore, the proton exchange membrane described above can be a perfluorosulfonic acid membrane. The catalyst layer slurry includes a Pt / C catalyst, perfluorosulfonic acid resin, carbon nanotubes, solvent, and deionized water. Before coating, the catalyst layer slurry is degassed using a degassing machine. The anode catalyst layer is applied using a direct coating method. The cathode catalyst layer is applied using an intermittent coating method, with several equally spaced rectangular coating areas coated on the proton exchange membrane.
[0047] The CCM anode catalyst layer overlaps with the central rectangular area of the membrane electrode frame, and the adhesive-coated surface of the membrane electrode frame is directly bonded to the proton exchange membrane of the CCM. The membrane electrode frame uses a single-layer polyamide or polyester material. A first gas diffusion layer is placed between the membrane electrode frame and the anode flow field groove, wherein the first gas diffusion layer is bonded to the membrane electrode frame. A second gas diffusion layer is placed between the cathode catalyst layer and the cathode flow field groove, wherein the second gas diffusion layer is bonded to the cathode catalyst layer. The adhesive uses one or more of polystyrene, polyether, polyether polyol, and epoxy resin. Preferably, the adhesive is a binary polyurethane material with polyester / polyether polyol as the main agent.
[0048] The cathode catalyst layer is applied using an intermittent coating method, while the anode catalyst layer is applied using a direct coating method. The catalyst coating film (CCM) is bonded to the adhesive-coated surface of a single-layer frame, which is then directly bonded to the anode flow channel surface of the bipolar plate. Grooves are cut into the anode and cathode flow channel surfaces of the bipolar plate to hold carbon paper; the depth of the grooves is equal to the thickness of the carbon paper after compression. One piece of carbon paper is sandwiched between the adhesive-coated surface of the frame and the flow channel, while another piece of carbon paper is placed directly on the non-adhesive-coated surface of the frame or adhered to the frame using carbon paper adhesive.
[0049] More specifically, the perfluorosulfonic acid proton exchange membrane has a thickness of 8-12 μm, and the membrane electrode frame material is selected from single-layer polyamide or polyester frame materials with a thickness of 20-40 μm. The cathode catalyst layer is applied intermittently with a platinum loading of 0.3-0.4 mg / cm³. 2 The anode catalyst layer is applied using a continuous direct coating method, with a platinum loading of 0.06-0.1 mg / cm³. 2 The catalyst layer is dried at a temperature of 60-100℃ for 2-8 minutes.
[0050] The modified carbon paper has a thickness of 180-250μm and a compression of 20-35%. The groove depth of the anode flow channel (i.e., the second groove) of the integrated air-cooled bipolar plate is 110-150μm, and the groove depth of the cathode flow channel (i.e., the first groove) is 120-160μm.
[0051] The present invention will be further described below with reference to specific embodiments.
[0052] Example 1
[0053] A method for fabricating a single-frame integrated air-cooled hydrogen fuel cell includes the following steps:
[0054] (1) Catalytic layer coating process;
[0055] The catalyst slurry was stirred evenly and then degassed using a vacuum degassing machine. The platinum loading of the cathode catalyst layer was preset to 0.4 mg / cm³. 2 The platinum loading of the anode catalyst layer is preset to 0.1 mg / cm³. 2 The cathode catalyst layer is first subjected to intermittent coating, where the catalyst slurry is uniformly coated onto the proton exchange membrane to a thickness of 10 μm. After drying at 75 °C for 5 min, a second direct coating is performed to a thickness of 5 μm, followed by drying at 90 °C for 5 min. The anode catalyst layer is subjected to a single intermittent coating, where the treated catalyst slurry is uniformly coated onto the surface of the proton exchange membrane to a thickness of 5 μm, followed by drying at 90 °C for 5 min.
[0056] (2) Single-cell assembly;
[0057] Align the anode catalyst layer with the central rectangular area of the membrane electrode frame, and directly bond the membrane electrode frame to the proton exchange membrane using adhesive. Bond the first gas diffusion layer to the anode catalyst layer using adhesive. Apply adhesive to the edges of the second gas diffusion layer to cover the cathode catalyst layer, and then bond it to the proton exchange membrane. The groove depth of the second groove in the anode channel of the integrated air-cooled bipolar plate is 120 μm, and the groove depth of the first groove in the cathode channel is 120 μm. Align the anode of the CCM membrane electrode with the anode channel of the integrated air-cooled bipolar plate with grooves on both sides, and align the cathode of the CCM membrane electrode with the cathode channel of the other integrated air-cooled bipolar plate with grooves on both sides. Clamp the two bipolar plates together to press the gas diffusion layers together.
[0058] For any parts not mentioned above, existing technologies can be adopted or referenced.
[0059] The above-described embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Any modifications and improvements made by those skilled in the art to the technical solutions of the present utility model without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.
Claims
1. A wind-cooled bipolar plate for a hydrogen fuel cell, characterized in that: The plate includes a plate body, a first groove is provided on one side of the plate body, a cathode flow channel is arranged in the first groove, a second groove is provided on the other side of the plate body, an anode flow channel is arranged in the second groove, and an air inlet and an air outlet are respectively provided at both ends of the plate body, and the air inlet and the air outlet are respectively connected to the two ends of the anode flow channel.
2. The air-cooled hydrogen fuel cell bipolar plate according to claim 1, characterized in that: The cathode flow channel adopts a parallel flow channel; the anode flow channel adopts a serpentine flow channel.
3. The air-cooled hydrogen fuel cell bipolar plate according to claim 1, characterized in that: The plate is rectangular, and the arrangement direction of the parallel flow channels is perpendicular to the extension direction of the plate; the main flow direction of the serpentine flow channel is consistent with the extension direction of the plate.
4. The air-cooled hydrogen fuel cell bipolar plate according to claim 3, characterized in that: The serpentine flow channel is provided in several groups, and the main body of each group of serpentine flow channels occupies a certain section of the second groove.
5. The air-cooled hydrogen fuel cell bipolar plate according to claim 1, characterized in that: A sealing groove is provided around the perimeter of the second groove.
6. The air-cooled hydrogen fuel cell bipolar plate according to claim 1, characterized in that: The groove depth of the first groove is 110-170μm, and the height of the cathode flow channel is less than the groove depth of the first groove.
7. The air-cooled hydrogen fuel cell bipolar plate according to claim 1, characterized in that: The groove depth of the second groove is 100-160μm; the height of the anode flow channel is less than the groove depth of the second groove.
8. A single battery, characterized in that: The bipolar plate described in any one of claims 1-7 further includes a CCM membrane electrode, a membrane electrode frame, a first gas diffusion layer, and a second gas diffusion layer. A rectangular opening adapted to the CCM membrane electrode is provided at the center of the membrane electrode frame. The CCM membrane electrode is fixed on the membrane electrode frame, the first gas diffusion layer is bonded to one side of the CCM membrane electrode, and the second gas diffusion layer is bonded to the other side of the CCM membrane electrode. One bipolar plate is disposed on one side of the membrane electrode frame, and after pressing, the first gas diffusion layer is located in the first groove of the bipolar plate. The other bipolar plate is disposed on the other side of the membrane electrode frame, and after pressing, the second gas diffusion layer is located in the second groove of the bipolar plate.
9. A single battery according to claim 8, characterized in that: Both the first and second gas diffusion layers are made of carbon paper, with a thickness of 150-260 μm and a compression of 15-40%.
10. A fuel cell stack, characterized in that: The arrangement employs several single cells stacked as described in claim 7, with adjacent single cells sharing a single bipolar plate.