A support structure for the bipolar plate flow guide region of a fuel cell

Abstract

This invention discloses a bipolar plate flow guide support structure for a fuel cell, including an anode plate, a cathode plate, and a membrane electrode assembly (MEA). The MEA assembly is located between the anode plate and the cathode plate. It includes a gas inlet / outlet area, a gas distribution area, and a gas reaction area. The gas reaction area is located in the middle of the fuel cell unit, the gas distribution area is located at both ends of the gas reaction area, and the gas inlet / outlet area is located at the end of the gas distribution area furthest from the gas reaction area. Through the structural design of the support structure on the anode plate, the seal between the MEA assembly and the bipolar plate is ensured. This allows the ridge of the cooling flow field to receive sufficient support when the gas pressure decreases during emergency stop conditions, improving the overall strength of the electrode plate, preventing deformation or even breakage, and enhancing the reliability of the electrode plate. Simultaneously, the gas diffusion layer coverage area is extended to the reaction area of ​​the bipolar plate.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a support structure for the bipolar plate flow channel of a fuel cell. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that uses hydrogen and oxygen from the air as reactants to undergo an electrochemical reaction to produce electricity. The only product generated during the reaction is water, causing no environmental pollution. It boasts high electrochemical efficiency, operates without noise or pollution, has fast hydrogen refueling speed, and offers a long driving range. A PEMFC is assembled by stacking anode plates, membrane electrode assemblies, and cathode plates sequentially, adding auxiliary components, and then performing a pressurized stack assembly.

[0003] like Figure 7 As shown, the membrane electrode assembly includes a proton exchange membrane coated with a catalyst, an anode-side gas diffusion layer, a cathode-side gas diffusion layer, and a frame. The components are bonded together. The area where the frame joins the membrane and diffusion layer is thicker than the rest, which can cause stress concentration in some areas.

[0004] There are generally three solutions:

[0005] Option 1 Figure 8 Without any special treatment, the thickness difference will cause stress concentration in some areas, and it will not be able to provide sufficient support for the cathode plate ridge, resulting in reduced plate reliability.

[0006] Option 2 Figure 9 As shown, the anode gas diffusion layer 302 and the cathode gas diffusion layer 303 cover the entire reaction zone and distribution zone. At the same time, the anode and cathode plates in the overlapping area are sunk to a certain height for compensation, which can ensure the seal between the membrane electrode assembly and the bipolar plates. However, this will lead to an increase in flow resistance due to the reduced tank depth, and also reduce the cooling effect. Furthermore, due to the presence of the sunken structure, the problem of uneven gas inlet and outlet distribution will be aggravated, and the processing difficulty will be increased. When the system experiences an emergency stop due to the gas supply problem of the anode and cathode, the gas side pressure decreases, and the pressure reduction in the water side distribution zone will be delayed. If the corresponding area does not have sufficient support, the water side pressure will be too high, which will weaken the electrode seal or even cause the electrode plate to fracture brittlely.

[0007] Option 3 Figure 10 As shown, the anode and cathode plates in the overlapping area are sunk to a certain height for compensation, but the carbon paper is not extended. This will increase the difficulty of distributing the reactive gas, worsen the problem of uneven gas distribution at the inlet and outlet, and increase the complexity of plate design and manufacturing. Since there is no gas diffusion layer covering the distribution area, the overall structure will lack support. Summary of the Invention

[0008] The purpose of this invention is to provide a support structure for the bipolar plate flow guide region of a fuel cell, so as to overcome the shortcomings of the prior art.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This application discloses a bipolar plate flow guide region support structure for a fuel cell, including an anode plate, a cathode plate, and a membrane electrode assembly, wherein the membrane electrode assembly is located between the anode plate and the cathode plate; it includes a gas inlet / outlet region, a gas distribution region, and a gas reaction region; the gas reaction region is located in the middle of the fuel cell unit, the gas distribution region is located at both ends of the gas reaction region, and the gas inlet / outlet region is located at the end of the gas distribution region away from the gas reaction region;

[0011] The gas inlet and outlet areas of the anode plate, cathode plate, and membrane electrode assembly are all provided with an anode gas inlet, an anode gas outlet, a cathode gas inlet, a cathode gas outlet, a coolant inlet, and a coolant outlet, wherein the anode gas inlet, cathode gas outlet, and coolant outlet are located at the same end; the anode gas outlet, cathode gas inlet, and coolant inlet are also located at the same end.

[0012] The anode plate has an anode gas inlet distribution area and an anode gas outlet distribution area on the gas distribution area on the side of the anode plate near the membrane electrode assembly, and an anode gas flow channel is provided on the gas reaction area on the side of the anode plate near the membrane electrode assembly.

[0013] The gas distribution area on the side of the anode plate away from the membrane electrode assembly is provided with a coolant inlet distribution area and a coolant outlet distribution area, and the gas reaction area on the side of the anode plate away from the membrane electrode assembly is provided with a coolant flow channel.

[0014] The cathode plate has a cathode gas inlet distribution area and a cathode gas outlet distribution area on the gas distribution area on the side of the cathode plate near the membrane electrode assembly, and a cathode gas flow channel on the gas reaction area on the side of the cathode plate near the membrane electrode assembly.

[0015] The anode gas inlet distribution area and the anode gas outlet distribution area are provided with supporting structures; the cathode plate has a cathode gas outlet distribution area on the side facing the membrane electrode assembly, and the supporting structure is directly opposite the cathode gas outlet distribution area;

[0016] The membrane electrode assembly includes a proton exchange membrane coated with a catalyst, an anode-side gas diffusion layer, a cathode-side gas diffusion layer, and a frame.

[0017] The anode-side gas diffusion layer and the cathode-side gas diffusion layer only cover the gas reaction zones of the anode plate and the cathode plate;

[0018] The depth of the gas distribution zone is the same as that of the gas reaction zone.

[0019] Preferably, the support structure includes adhesive strips disposed within the anode gas inlet distribution area and the anode gas outlet distribution area.

[0020] Preferably, the anode plate is provided with an anode gas sealing groove and a coolant sealing groove; the anode gas sealing groove is located on the outer periphery of the anode gas flow channel and the inlet and outlet of the anode gas, cathode gas, and coolant, and the coolant sealing groove is located on the outer periphery of the coolant flow channel and the inlet and outlet of the anode gas, cathode gas, and coolant; the cathode plate is provided with a cathode gas sealing groove, which is located on the outer periphery of the cathode gas flow channel and the inlet and outlet of the anode gas, cathode gas, and coolant.

[0021] Preferably, the supporting structure material is one of silicone, polyolefin, polyurethane, polyamide, polyester, or EPDM.

[0022] Preferably, the support structure is manufactured by one of the following methods: dispensing, screen printing, or injection molding.

[0023] Preferably, the anode plate and cathode plate are made of graphite or composite graphite.

[0024] Preferably, the cathode plate and the gas distribution area corresponding to the support structure are both provided with ridges, which are evenly distributed among each other, and the ridges are directly opposite the adhesive strip.

[0025] Preferably, the angle between the support structure and the ridge of the cathode gas outlet distribution area is 150°~180°.

[0026] Preferably, the width of the support structure is in the range of 0.5mm to 2mm.

[0027] Preferably, the support structure is a segmented adhesive strip, and the spacing between the segmented adhesive strips is 1mm to 4mm.

[0028] The beneficial effects of this invention are:

[0029] (1) Through the structural design of the support structure on the anode plate, the sealing between the membrane electrode assembly and the bipolar plate can be guaranteed, so that the ridge of the cooling flow field can be supported by sufficient force when the gas pressure drops under emergency stop conditions, thereby improving the overall strength of the plate, avoiding deformation or even breakage of the plate, improving the reliability of the plate, and at the same time stopping the gas diffusion layer coverage area to the reaction zone of the bipolar plate.

[0030] (2) Through the structural design of the support structure on the anode plate, it can be combined with the ridge of the cathode gas outlet distribution area of ​​the cathode plate. On the basis of ensuring the sealing, the ridge of the cooling flow field can be supported by sufficient force when the gas pressure drops under emergency stop conditions, thereby improving the overall strength of the plate, avoiding deformation or even breakage of the plate, and improving the reliability of the plate.

[0031] The features and advantages of the present invention will be described in detail through embodiments and in conjunction with the accompanying drawings. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the planar structure of the anode plate of the present invention;

[0033] Figure 2 This is a three-dimensional structural schematic diagram of a fuel cell bipolar plate flow guide region support structure according to the present invention.

[0034] Figure 3 This is a schematic diagram of the planar structure of the other side of the anode plate of the present invention;

[0035] Figure 4 This is a schematic diagram of the planar structure of the cathode plate of the present invention;

[0036] Figure 5 This is a schematic planar structural diagram of the membrane electrode assembly of the present invention;

[0037] Figure 6 This is a schematic diagram of the planar structure of the support structure of the present invention;

[0038] Figure 7 This is a schematic diagram of the structure of a membrane electrode in the prior art;

[0039] Figure 8 This is a schematic diagram of the flow guiding region structure of a fuel cell bipolar plate in existing technology;

[0040] Figure 9 This is a schematic diagram of the flow guiding region structure of a fuel cell bipolar plate in existing technology;

[0041] Figure 10 This is a schematic diagram of the flow guiding region structure of a fuel cell bipolar plate in existing technology;

[0042] In the diagram: 1-Anode plate, 101-Anode gas inlet, 102-Anode gas outlet, 103-Anode gas inlet distribution area, 104-Anode gas flow channel, 105-Anode gas outlet distribution area, 111-Cathode gas inlet, 112-Cathode gas outlet, 121-Coolant inlet, 122-Coolant outlet, 123-Coolant inlet distribution area, 124-Coolant flow channel, 125-Coolant outlet distribution area, 131-Anode gas sealing groove, 141-Coolant sealing groove, 151-Support structure, 2-Cathode plate, 213-Cathode gas inlet distribution area, 214-Cathode gas flow channel, 215-Cathode gas outlet distribution area, 231-Cathode gas sealing groove, 3-Membrane electrode assembly, 301-Proton exchange membrane, 302-Anode side gas diffusion layer, 303-Cathode side gas diffusion layer, 304-Frame. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0044] See Figures 1-6 This invention provides a bipolar plate flow guide zone support structure for a fuel cell, including an anode plate 1, a cathode plate 2, and a membrane electrode assembly 3, wherein the membrane electrode assembly 3 is located between the anode plate 1 and the cathode plate 2; it includes a gas inlet / outlet zone, a gas distribution zone, and a gas reaction zone; the gas reaction zone is located in the middle of the fuel cell bipolar plate, the gas distribution zone is located at both ends of the gas reaction zone, and the gas inlet / outlet zone is located at the end of the gas distribution zone away from the gas reaction zone;

[0045] The gas inlet and outlet areas of the anode plate 1, cathode plate 2, and membrane electrode assembly 3 are all provided with an anode gas inlet 101, an anode gas outlet 102, a cathode gas inlet 111, a cathode gas outlet 112, a coolant inlet 121, and a coolant outlet 122, wherein the anode gas inlet 101, the cathode gas outlet 112, and the coolant outlet 122 are located at the same end; the anode gas outlet 102, the cathode gas inlet 111, and the coolant inlet 121 are located at the same end.

[0046] The anode plate 1 is provided with an anode gas inlet distribution area 103 and an anode gas outlet distribution area 105 on the gas distribution area on the side of the anode plate 1 near the membrane electrode assembly 3, and an anode gas flow channel 104 is provided on the gas reaction area on the side of the anode plate 1 near the membrane electrode assembly 3.

[0047] The anode plate 1 is provided with a coolant inlet distribution area 123 and a coolant outlet distribution area 125 on the gas distribution area on the side away from the membrane electrode assembly 3, and a coolant flow channel 124 is provided on the gas reaction area on the side away from the membrane electrode assembly 3.

[0048] The cathode plate 2 is provided with a cathode gas inlet distribution area 213 and a cathode gas outlet distribution area 215 on the gas distribution area on the side of the cathode plate 2 near the membrane electrode assembly 3, and a cathode gas flow channel 214 on the gas reaction area on the side of the cathode plate 2 near the membrane electrode assembly 3.

[0049] A support structure 151 is provided in the anode gas inlet distribution area 103 and the anode gas outlet distribution area 105; a cathode gas outlet distribution area 215 is provided on the side of the cathode plate 2 facing the membrane electrode assembly 3, and the support structure 151 is directly opposite the cathode gas outlet distribution area 215.

[0050] The membrane electrode assembly 3 includes a proton exchange membrane 301 coated with a catalyst, an anode-side gas diffusion layer 302, a cathode-side gas diffusion layer 303, and a frame 304.

[0051] The anode-side gas diffusion layer 302 and the cathode-side gas diffusion layer 303 only cover the gas reaction zones of the anode plate 1 and the cathode plate 2;

[0052] The depth of the gas distribution zone is the same as that of the gas reaction zone.

[0053] The support structure includes adhesive strips provided in the anode gas inlet distribution area 103 and the anode gas outlet distribution area 105.

[0054] The anode plate 1 is provided with an anode gas sealing groove 131 and a coolant sealing groove 141; the anode gas sealing groove 131 is located on the outer periphery of the anode gas flow channel 104 and the inlet and outlet of the anode gas, cathode gas, and coolant, and the coolant sealing groove 141 is located on the outer periphery of the coolant flow channel 124 and the inlet and outlet of the anode gas, cathode gas, and coolant; the cathode plate 2 is provided with a cathode gas sealing groove 231, which is located on the outer periphery of the cathode gas flow channel 214 and the inlet and outlet of the anode gas, cathode gas, and coolant.

[0055] The material of the support structure 151 is one of silicone, polyolefin, polyurethane, polyamide, polyester or EPDM.

[0056] The support structure is manufactured by one of the following methods: dispensing, screen printing, or injection molding.

[0057] The anode plate 1 and cathode plate 2 are made of graphite or composite graphite materials.

[0058] The cathode plate 2 and the gas distribution area corresponding to the support structure are both provided with ridges, which are evenly distributed among each other, and the ridges are directly opposite the adhesive strip.

[0059] The angle between the support structure and the ridge of the cathode gas outlet distribution area 215 is 150°~180°.

[0060] The width of the support structure ranges from 0.5mm to 2mm.

[0061] The support structure is a segmented rubber strip, and the spacing between the segmented rubber strips is 1mm to 4mm.

[0062] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A fuel cell bipolar plate flow field support structure comprising an anode plate, a cathode plate and a membrane electrode assembly, the membrane electrode assembly being intermediate the anode plate and the cathode plate; characterized by: The gas inlet and outlet area, the gas distribution area and the gas reaction area; the gas reaction area is located in the middle of the fuel cell unit, the gas distribution area is located at both ends of the gas reaction area, and the gas inlet and outlet area is located at one end of the gas distribution area away from the gas reaction area; The anode plate, the cathode plate and the gas inlet and outlet area of the membrane electrode assembly are provided with an anode gas inlet, an anode gas outlet, a cathode gas inlet, a cathode gas outlet, a coolant inlet and a coolant outlet, wherein the anode gas inlet, the cathode gas outlet and the coolant outlet are located at the same end; the anode gas outlet, the cathode gas inlet and the coolant inlet are located at the same end; The anode plate is provided with an anode gas inlet distribution area and an anode gas outlet distribution area on the gas distribution area close to the membrane electrode assembly; and the anode plate is provided with an anode gas flow channel on the gas reaction area close to the membrane electrode assembly; The anode plate is provided with a coolant inlet distribution area and a coolant outlet distribution area on the gas distribution area away from the membrane electrode assembly; and the anode plate is provided with a coolant flow channel on the gas reaction area away from the membrane electrode assembly; The cathode plate is provided with a cathode gas inlet distribution area and a cathode gas outlet distribution area on the gas distribution area close to the membrane electrode assembly; and the cathode plate is provided with a cathode gas flow channel on the gas reaction area close to the membrane electrode assembly; The anode gas inlet distribution area and the anode gas outlet distribution area are provided with a support structure; the cathode plate is provided with a cathode gas outlet distribution area on the side facing the membrane electrode assembly, and the support structure is opposite to the cathode gas outlet distribution area; The membrane electrode assembly comprises a proton exchange membrane coated with a catalyst, an anode-side gas diffusion layer and a cathode-side gas diffusion layer, and a frame; The anode-side gas diffusion layer and the cathode-side gas diffusion layer only cover the gas reaction areas of the anode plate and the cathode plate; The depth of the gas distribution area is consistent with that of the gas reaction area; The support structure comprises adhesive strips provided in the anode gas inlet distribution area and the anode gas outlet distribution area; the support structure is a segmented adhesive strip, and the spacing between the segmented adhesive strips is 1mm-4mm; The cathode plate and the corresponding gas distribution area of the support structure are both provided with ridges, the ridges are uniformly distributed, and the ridges are opposite to the adhesive strips; The angle between the support structure and the ridges of the cathode gas outlet distribution area is 150°-180°.

2. A fuel cell bipolar plate flow field support structure as in claim 1, wherein: The anode plate is provided with an anode gas sealing groove and a coolant sealing groove; the anode gas sealing groove is located on the outer circumferential side of the anode gas flow channel and the anode gas inlet and outlet; the coolant sealing groove is located on the outer circumferential side of the coolant flow channel and the anode gas inlet and outlet; the cathode plate is provided with a cathode gas sealing groove, and the cathode gas sealing groove is located on the outer circumferential side of the cathode gas flow channel and the anode gas inlet and outlet.

3. A fuel cell bipolar plate flow field support structure as in claim 1, wherein: The material of the support structure is one of silicone adhesive, polyolefin, polyurethane, polyamide, polyester or ethylene-propylene-diene terpolymer.

4. The flow field region support structure for a bipolar plate of a fuel cell of claim 1, wherein: The manufacturing method of the support structure is one of dispensing, silk printing or injection molding.

5. A fuel cell bipolar plate flow field support structure as in claim 1, wherein: The anode plate and the cathode plate are made of graphite or composite graphite material.

6. A fuel cell bipolar plate flow field support structure as described in claim 1 wherein: The support structure has a width ranging from 0.5mm to 2mm.

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