Cathode open-air cooled fuel cell bipolar plate assembly and fuel cell

Abstract

The present invention discloses a cathode open-air cooled fuel cell bipolar plate assembly and a fuel cell, relating to the technical field of fuel cells. Among them, the bipolar plate assembly includes a single-layer bipolar plate. The bipolar plate includes a first end, a second end and a wavy section, and the first end and the second end are respectively connected to both ends of the length direction of the wavy section. The troughs on the anode side of the wavy section are anode grooves, and the troughs on the cathode side of the wavy section are cathode grooves. Both the anode grooves and the cathode grooves extend to both ends of the width direction of the wavy section. The edge on the anode side of the bipolar plate is used for sealing contact with a cavity so that a plurality of anode grooves communicate with each other. The first end is provided with an air inlet for supplying hydrogen into the cavity, and the second end is provided with an air outlet for discharging the gas in the cavity. The present invention integrates the anode grooves and the cathode grooves on one plate, reducing the overall weight, lowering the mold development cost and the coating cost, avoiding the problems of increased contact thermal resistance and resistance, and being able to ensure the heat dissipation efficiency and performance of the fuel cell.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, and particularly to a cathode open air-cooled fuel cell bipolar plate assembly and a fuel cell. Background Art

[0002] As an efficient energy conversion device, a fuel cell can use hydrogen and oxygen as reaction gases, and through an electrochemical reaction, convert the chemical energy of the fuel into electrical energy. A cathode open air-cooled fuel cell is a fuel cell that uses a fan to achieve oxygen supply and heat dissipation functions, and is mainly applicable to occasions with small power requirements, such as unmanned aerial vehicles, mobile power supplies, etc. Its power range is usually between 10 W and 5 kW. Its structure mainly consists of an end plate, a bipolar plate, a membrane electrode assembly, electrical connectors, fasteners, and seals, etc. The core component of an air-cooled fuel cell is the membrane electrode, which is used for electrochemical reactions. The bipolar plate is the "skeleton" of the battery, and is stacked and assembled with the membrane electrode, and is used to supply reactants to the electrode, playing roles such as supporting the fuel cell, collecting current, providing channels, and separating different reactants.

[0003] The existing air-cooled fuel cell bipolar plate includes an anode plate and a cathode plate. The anode plate and the cathode plate are stacked up and down. The end face of the anode plate is provided with an anode flow field, and the anode flow field is provided with an anode flow channel with two open ends along the long side direction of the battery for hydrogen to enter and exit; the end face of the cathode plate is provided with a cathode flow field, and the cathode flow field is provided with a cathode flow channel with two open ends along the short side direction of the battery for air to enter and exit, and the anode flow channel and the cathode flow channel are perpendicular. This bipolar plate has the following disadvantages:

[0004] 1. The anode plate and the cathode plate usually adopt an assembly method of laser welding or pressing, which may result in situations such as virtual welding or partial displacement of the bipolar plate caused by pressure, resulting in an increase in the contact thermal resistance and resistance of the bipolar plate, and a decrease in the heat dissipation efficiency and performance of the battery.

[0005] 2. The bipolar plate accounts for 60% - 80% of the total weight of the fuel cell and 50% - 65% of the total volume of the battery, which is not conducive to meeting the application requirements of lightweight and small-volume unmanned aerial vehicles.

[0006] 3. The development cost of the bipolar plate mold is high, and the coating process cost of the metal bipolar plate is high. Summary of the Invention

[0007] The purpose of the present invention is to provide a cathode open air-cooled fuel cell bipolar plate assembly and a fuel cell, which can effectively reduce the body resistance of the bipolar plate and the contact resistance and thermal resistance generated by laser welding, thereby improving the heat dissipation performance and overall electrochemical performance of the fuel cell.

[0008] To achieve the above purpose, the present invention provides the following solutions:

[0009] The present invention discloses a cathode open air-cooled fuel cell bipolar plate assembly, comprising a bipolar plate, wherein the bipolar plate is a single-layer plate; the bipolar plate comprises a first end, a second end and a wave section, wherein the first end and the second end are respectively connected to two ends of the wave section in a length direction;

[0010] The trough on the anode side of the wave segment is an anode slot, and the trough on the cathode side of the wave segment is a cathode slot, and both the anode slot and the cathode slot extend to both ends of the wave segment in the width direction;

[0011] The edge of the anode side of the bipolar plate is used to seal and contact with a cavity so that multiple anode slots are interconnected; the first end is provided with an inlet for supplying hydrogen into the cavity, and the second end is provided with an outlet for discharging gas in the cavity.

[0012] Preferably, the anode slot and the cathode slot are straight slots, and the extension direction of the straight slots is parallel to the width direction of the wave segment.

[0013] Preferably, the cavity comprises a sealing ring, the edge of the anode side of the bipolar plate is in sealing contact with the sealing ring, and a through hole is provided on the sealing ring at a position directly opposite to the air inlet and the air outlet.

[0014] Preferably, the first end and the second end both have a first edging, and both ends of the sealing ring in the length direction and the width direction are against the first edging; the edges of the air inlet and the air outlet have a second edging, and the second edging is used to contact and position with the corresponding through holes on the sealing ring.

[0015] Preferably, the number of the air inlet and the number of the air outlet are both plural.

[0016] Preferably, the plurality of air inlets and the plurality of air outlets are arranged along a straight line, and the straight line is parallel to the width direction of the wave segment.

[0017] Preferably, the cavity further comprises an annular gasket, which is located on a side of the sealing ring away from the bipolar plate and is used to press the sealing ring toward the bipolar plate.

[0018] Preferably, the annular gasket is made of metal or polymer material.

[0019] Preferably, the anode slot and the cathode slot are both rectangular slots, the slot width of the rectangular slot is 1.5-2 mm, and the slot depth of the rectangular slot is 1.5-2 mm.

[0020] The present invention also discloses a fuel cell, comprising the above-mentioned cathode open air-cooled fuel cell bipolar plate assembly.

[0021] The present invention has achieved the following technical effects compared with the related art:

[0022] In this embodiment, the anode tank and the cathode tank are integrated on one plate, eliminating the need to stack the anode plate and the cathode plate. On the basis of ensuring performance, the overall weight is reduced, realizing a lightweight design.

[0023] After hydrogen enters the cavity from the air inlet, the flow path in the cavity is wavy, increasing the gas pressure in the flow field and improving the electrochemical performance of the fuel cell.

[0024] Due to the simplification of the structure and the reduction in the number of components, the demand for complex molds is reduced, and the coating area of the surface coating is decreased, lowering the mold development cost and the coating cost.

[0025] Since there is no need to use laser welding or press fitting for the anode plate and the cathode plate, the problems of increased contact thermal resistance and resistance are avoided, thus ensuring the heat dissipation efficiency and performance of the fuel cell.

[0026] In the preferred solution of the present invention, by virtue of the tight fit between the annular gasket and the sealing ring, and the contact limit of the sealing ring with the first edge wrapping and the second edge wrapping respectively, it is ensured that the sealing element is not easily displaced during the assembly process. Additionally, by means of the tight fit between the annular gasket and the sealing ring, the assembly pressure is evenly distributed, preventing assembly problems such as local over-tightening or over-loosening, thereby reducing the risk of gas leakage and enhancing the sealing performance of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the related art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0028] Figure 1 It is a schematic assembly relationship diagram of the bipolar plate assembly of the cathode open-air-cooled fuel cell according to the embodiment of the present invention;

[0029] Figure 2 It is a front view of the bipolar plate;

[0030] Figure 3 It is a top view of the bipolar plate;

[0031] Figure 4 It is a partial schematic diagram of the bipolar plate assembly of the cathode open-air-cooled fuel cell according to the embodiment of the present invention;

[0032] Figure 5 It is a schematic diagram of the linear first edge wrapping;

[0033] Figure 6Schematic diagram of edge wrapping two;

[0034] Figure 7 Schematic diagram of wavy edge wrapping one.

[0035] In the figure: 1 - bipolar plate; 2 - sealing ring; 3 - annular gasket; 4 - protrusion; 5 - air inlet; 6 - air outlet; 7 - flow direction of hydrogen on the anode side; 8 - flow direction of air on the cathode side; 9 - edge wrapping one; 10 - edge wrapping two. Specific implementation mode

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0037] The purpose of the present invention is to provide a cathode open - air - cooled fuel cell bipolar plate assembly and a fuel cell, which can effectively reduce the bulk resistance of the bipolar plate and the contact resistance and thermal resistance generated by laser welding, thereby improving the heat dissipation performance and overall electrochemical performance of the fuel cell.

[0038] In order to make the above - mentioned objects, features and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation modes.

[0039] Referring to Figures 1 to 7 , this embodiment provides a cathode open - air - cooled fuel cell bipolar plate assembly, including a bipolar plate 1, and the bipolar plate 1 is a single - layer plate. The bipolar plate 1 includes a first end, a second end and a wavy section. The first end and the second end are respectively connected to both ends of the wavy section in the length direction.

[0040] The trough on the anode side of the wavy section is the anode groove, and the trough on the cathode side of the wavy section is the cathode groove. Both the anode groove and the cathode groove extend to both ends of the wavy section in the width direction. The length direction of the wavy section is the length direction of the bipolar plate 1, and the width direction of the wavy section is the width direction of the bipolar plate 1.

[0041] The edge on the anode side of the bipolar plate 1 is used for sealing contact with a cavity so that a plurality of anode grooves communicate with each other. The first end is provided with an air inlet 5 for supplying hydrogen into the cavity, and the second end is provided with an air outlet 6 for discharging the gas in the cavity.

[0042] The working principle of the cathode open - air - cooled fuel cell bipolar plate assembly in this embodiment is as follows:

[0043] The bipolar plate 1 of this embodiment has a wavy section. By utilizing the wavy shape characteristics of the wavy section, an anode groove and a cathode groove are respectively formed on the anode side and the cathode side of the bipolar plate 1. Hydrogen enters the cavity through the inlet 5 and flows along the length direction of the wavy section, providing a continuous fuel supply for the electrochemical reaction. The excess hydrogen and reaction by-products are discharged through the outlet 6. Air enters from one end of the cathode groove and flows along the width direction of the wavy section, providing oxygen to participate in the reaction, while taking away part of the heat and the water generated by the reaction. The excess air and the water generated by the reaction are discharged from the other end of the cathode groove.

[0044] In this embodiment, the anode groove and the cathode groove are integrated on one plate, eliminating the need to stack the anode plate and the cathode plate. On the basis of ensuring performance, the overall weight is reduced, achieving a lightweight design.

[0045] After hydrogen enters the cavity through the inlet 5, its flow path in the cavity is wavy, increasing the gas pressure in the flow field and improving the electrochemical performance of the fuel cell.

[0046] Due to the simplification of the structure and the reduction in the number of components, the demand for complex molds is reduced, and the coating area of the surface coating is reduced, lowering the mold development cost and the coating cost.

[0047] Moreover, since there is no need to use laser welding or press fitting for the anode plate and the cathode plate, the problems of increased contact thermal resistance and resistance are avoided, thus ensuring the heat dissipation efficiency and performance of the fuel cell.

[0048] As a possible example, in this embodiment, the anode groove and the cathode groove are straight grooves, and the extending direction of the straight grooves is parallel to the width direction of the wavy section.

[0049] It can be understood that the anode groove and the cathode groove can also be straight grooves forming a certain angle with the width direction of the wavy section; the anode groove and the cathode groove can also be curved grooves, and in this case, both extend in a curve.

[0050] As a possible example, in this embodiment, the cavity includes a sealing ring 2. The edge of the anode side of the bipolar plate 1 is in sealing contact with the sealing ring 2, and through holes are provided at positions on the sealing ring 2 opposite to the inlet 5 and the outlet 6.

[0051] It can be understood that the side of the sealing ring 2 in contact with the wavy section is a wavy surface consistent with the shape of the wavy section to achieve close contact with the wavy section.

[0052] Exemplarily, the cross-sections of both the anode groove and the cathode groove are square; the sealing ring 2 includes a substrate and a protrusion 4. The protrusion 4 is fixedly connected to the side of the substrate facing the wavy section and is used to extend into one end of the anode groove and contact and seal the bottom and side walls of the anode groove; the cross-section of the protrusion 4 is square.

[0053] As a possible example, in this embodiment, referring to Figure 5 , Figure 7 , both the first end and the second end have a first edge trim 9, and both ends in the length direction and both ends in the width direction of the sealing ring 2 abut against the first edge trim 9.

[0054] The first edge trim 9 of the bipolar plate 1 is used to limit the sealing ring 2 to prevent the sealing ring 2 from sliding and shifting relative to the bipolar plate 1, thereby ensuring the sealing performance and avoiding hydrogen leakage.

[0055] The type of the first edge trim 9 can be flexibly selected, such as a straight type (refer to Figure 5 ) and a wavy type (refer to Figure 7 ). For a bipolar plate with a larger width, by setting the first edge trim 9 as a wavy shape, the deformation caused by stress is reduced, preventing air leakage.

[0056] As a possible example, in this embodiment, the numbers of the air inlet 5 and the air outlet 6 are both multiple.

[0057] Exemplarily, both the air inlet 5 and the air outlet 6 are three, and adjacent two air inlets 5 and adjacent two air outlets 6 are separated by ribs. If the ribs are removed, multiple air inlets 5 and multiple air outlets 6 both form a rectangular hole with rounded corners.

[0058] Exemplarily, the length of the rectangular hole with rounded corners is 40 mm, and the width is 4 mm. The width of the rib is 1 mm, and the length is 4 mm (the width direction of the rib is the length direction of the rectangular hole with rounded corners).

[0059] As a possible example, in this embodiment, referring to Figure 6 , on the bipolar plate 1, the edges of the air inlet 5 and the air outlet 6 have a second edge trim 10, and the second edge trim 10 is used to contact and position with the corresponding through holes on the sealing ring 2 to prevent the sealing ring 2 from sliding and shifting relative to the bipolar plate 1, thereby ensuring the sealing performance and avoiding hydrogen leakage.

[0060] Exemplarily, the thicknesses of the first edge trim 9 and the second edge trim 10 are the same as the thickness of the bipolar plate 1, and the heights of the first edge trim 9 and the second edge trim 10 are 0.1 - 0.5 mm.

[0061] As a possible example, in this embodiment, multiple air inlets 5 and multiple air outlets 6 are both arranged in a straight line, and the straight line is parallel to the width direction of the wavy section.

[0062] This arrangement can make the hydrogen on the anode side more evenly distributed in the width direction of the bipolar plate 1, thereby improving the power generation efficiency of the fuel cell.

[0063] As a possible example, in this embodiment, the cavity further includes an annular gasket 3. The annular gasket 3 is located on the side of the sealing ring 2 away from the bipolar plate 1 and is used to press the sealing ring 2 against the bipolar plate 1.

[0064] Exemplarily, the outer contours of the annular gasket 3, the sealing ring 2, and the bipolar plate 1 are the same.

[0065] By using the tight fit between the annular gasket 3 and the sealing ring 2, it is ensured that the sealing element is not easily displaced during the assembly process, and the assembly pressure is evenly distributed, preventing assembly problems such as local over-tightening or over-loosening, thereby reducing the risk of gas leakage and improving the sealing performance of the fuel cell.

[0066] It should be noted that if the sealing element is improperly installed, aged, or mechanically damaged during the assembly process, gas leakage may occur, especially in high-temperature, high-pressure, or vibration environments. Such leakage not only reduces the efficiency of the fuel cell but also poses a threat to the safety of the fuel cell.

[0067] In this embodiment, through the settings of the first edge 9 and the second edge 10, the bipolar plate 1 and the sealing ring 2 are mutually limited in position, ensuring the position stability of the sealing ring 2; by applying pressure to the sealing ring 2 evenly through the annular gasket 3, the adhesion between the sealing ring 2 and the bipolar plate 1 is ensured. Therefore, this embodiment can solve the problem of unstable sealing performance of the sealing element in the prior art.

[0068] As a possible example, in this embodiment, the bipolar plate 1 is made of metal or graphite, and the annular gasket 3 is made of metal or polymer.

[0069] Exemplarily, the metal material here can be stainless steel, aluminum alloy, etc., and the polymer material can be polyphenylene sulfide (PPS), polyether ether ketone (PEEK), etc.

[0070] As a possible example, in this embodiment, both the anode groove and the cathode groove are rectangular grooves. The groove width of the rectangular groove is 1.5 - 2 mm, and the groove depth of the rectangular groove is 1.5 - 2 mm.

[0071] This embodiment also provides a fuel cell, including the above-mentioned cathode open-air-cooled fuel cell bipolar plate assembly.

[0072] Since this fuel cell includes the above-mentioned cathode open-air-cooled fuel cell bipolar plate assembly, it also has the corresponding advantages of the cathode open-air-cooled fuel cell bipolar plate assembly, which will not be elaborated here.

[0073] In the present invention, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A cathode open-type air-cooled fuel cell bipolar plate assembly, characterized in that The bipolar plate comprises a single-layer plate, wherein the bipolar plate comprises a first end, a second end and a wave segment, wherein the first end and the second end are respectively connected to two ends of the wave segment in a length direction; The trough on the anode side of the wave segment is an anode slot, and the trough on the cathode side of the wave segment is a cathode slot, and both the anode slot and the cathode slot extend to both ends of the wave segment in the width direction; The edge of the anode side of the bipolar plate is used to seal and contact with a cavity so that the multiple anode tanks are interconnected; the first end is provided with an inlet for supplying hydrogen into the cavity, and the second end is provided with an outlet for discharging the gas in the cavity; The anode slot and the cathode slot are straight slots, and the extension direction of the straight slots is parallel to the width direction of the wave segment; The cavity includes a sealing ring, the edge of the anode side of the bipolar plate is in sealing contact with the sealing ring, and a through hole is provided on the sealing ring at a position directly opposite to the air inlet and the air outlet; the sealing ring includes a substrate and a protrusion, the protrusion is fixedly connected to a side of the substrate facing the wave section, and is used to extend into one end of the anode tank and contact and seal with the bottom and side wall of the anode tank; The first end and the second end both have a first edge, and both ends of the sealing ring in the length direction and the width direction are against the first edge; the edges of the air inlet and the air outlet have a second edge, and the second edge is used to contact and position with the corresponding through hole on the sealing ring; The cavity further comprises an annular gasket, which is located at a side of the sealing ring away from the bipolar plate and is used to press the sealing ring toward the bipolar plate.

2. The cathode open-air cooled fuel cell bipolar plate assembly according to claim 1, wherein: The number of the air inlet and the number of the air outlet are both multiple.

3. The cathode open-air-cooled fuel cell bipolar plate assembly according to claim 2, wherein: The plurality of air inlets and the plurality of air outlets are arranged along a straight line, and the straight line is parallel to the width direction of the wave segment.

4. The cathode open-air cooled fuel cell bipolar plate assembly according to claim 1, characterized in that: The annular gasket is made of metal or polymer material.

5. The cathode open-air cooled fuel cell bipolar plate assembly according to claim 1, wherein: The anode slot and the cathode slot are both rectangular slots, the slot width of the rectangular slot is 1.5-2 mm, and the slot depth of the rectangular slot is 1.5-2 mm.

6. A fuel cell, characterized in that, It comprises the cathode open air-cooled fuel cell bipolar plate assembly as described in any one of claims 1 to 5.

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