Fuel cell polar plate, bipolar plate and fuel cell

Abstract

The application provides a fuel cell polar plate, a bipolar plate and a fuel cell. The bipolar plate of the fuel cell is provided with a plurality of polar ridges arranged at intervals on one side, a flow channel is formed between two adjacent polar ridges, the flow channel comprises an expansion area and a contraction area which are communicated with each other, the expansion area and the contraction area are arranged alternately along the extension direction of the flow channel, the flow area of the expansion area is larger than that of the contraction area, and a protruding part is further arranged on the fuel cell polar plate and located in the expansion area. Through the technical scheme provided in the application, the problem of blockage of the flow channel of the gas diffusion layer in the prior art can be solved.

Description

Technical Field

[0001] This invention relates to the field of fuel cells, and more specifically, to a fuel cell electrode plate, a bipolar plate, and a fuel cell. Background Technology

[0002] Bipolar plates are a key component of fuel cells, consisting of two plates welded together. They play crucial roles in gas distribution, electrical conductivity, heat conduction, and water drainage. Typically, bipolar plates have flow channels to ensure uniform gas flow and achieve optimal gas supply. During fuel cell assembly, bipolar plates and membrane electrode assemblies (MEAs) are stacked sequentially, bringing the flow channels into contact with the MEAs. Because the gas diffusion layer in the MEAs is porous, some of the diffusion layer may be forced into areas with larger cross-sectional areas within the flow channels after fuel cell assembly. This can lead to blockage of the flow channels, hindering gas flow and reducing fuel cell performance. Summary of the Invention

[0003] This invention provides a fuel cell electrode plate, a bipolar plate, and a fuel cell to solve the problem of easy blockage of the flow channel by the gas diffusion layer in the prior art.

[0004] According to one aspect of the present invention, a fuel cell electrode plate is provided, wherein a plurality of spaced-apart ridges are provided on one side, and a flow channel is formed between two adjacent ridges. The flow channel includes an expansion region and a contraction region that are interconnected. The expansion region and the contraction region are alternately arranged along the extension direction of the flow channel. The flow area of ​​the expansion region is larger than the flow area of ​​the contraction region. The fuel cell electrode plate is also provided with a protrusion located within the expansion region, and there is a gap between the protrusion and the inner wall of the expansion region.

[0005] Furthermore, the expansion region has a first inner sidewall and a second inner sidewall disposed opposite to each other, and the protrusion has a first protruding sidewall and a second protruding sidewall disposed opposite to each other. The first inner sidewall is disposed opposite to the first protruding sidewall, the second inner sidewall is disposed opposite to the second protruding sidewall, the first inner sidewall and the first protruding sidewall are disposed at equal intervals, and / or the second inner sidewall and the second protruding sidewall are disposed at equal intervals.

[0006] Furthermore, the distance between the first inner sidewall and the first protruding sidewall is equal to the distance between the second inner sidewall and the second protruding sidewall.

[0007] Furthermore, the contraction zone has a third inner sidewall and a fourth inner sidewall disposed opposite to each other, the distance between the third inner sidewall and the fourth inner sidewall being less than the distance between the first inner sidewall and the first protruding sidewall, and / or the distance between the third inner sidewall and the fourth inner sidewall being less than the distance between the second protruding sidewall and the second inner sidewall.

[0008] Furthermore, the flow channel has a central axis, which is located between two adjacent pole ridges. The extension direction of the central axis is the same as the extension direction of the fuel cell pole plates, and the two adjacent pole ridges are symmetrically arranged relative to the central axis.

[0009] Furthermore, the ridge has a corrugated structure along its extension direction.

[0010] Furthermore, the surface of the protrusion is curved.

[0011] Furthermore, the height of the protrusion is between 0.9 and 1.1 times the height of the ridge.

[0012] According to another aspect of the invention, a bipolar plate is provided, comprising two fuel cell plates as described above, welded together.

[0013] According to another aspect of the present invention, a fuel cell is provided, which includes the fuel cell plates described above.

[0014] When assembling a fuel cell using the technical solution of this invention, the protrusion occupies part of the expansion zone and supports the membrane electrode. Therefore, the protrusion can reduce the depth of the membrane electrode embedded in the expansion zone, avoid the phenomenon of the membrane electrode blocking the flow channel, and thus ensure the smooth flow of gas and the working performance of the fuel cell. Attached Figure Description

[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0016] Figure 1 A schematic diagram of the structure of the fuel cell electrode plate provided by the present invention is shown;

[0017] Figure 2 This invention provides... Figure 1 A magnified view of a portion at point A.

[0018] The above figures include the following reference numerals:

[0019] 10. Extreme ridge; 21. Expansion zone; 22. Contraction zone; 30. Protrusion. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a fuel cell electrode plate with multiple spaced-apart ridges 10 on one side. A flow channel is formed between adjacent ridges 10, and the flow channel includes interconnected expansion regions 21 and contraction regions 22. The expansion regions 21 and contraction regions 22 are alternately arranged along the extension direction of the flow channel. The flow area of ​​the expansion region 21 is larger than that of the contraction region 22. A protrusion 30 is also provided on the fuel cell electrode plate, located within the expansion region 21. A gap exists between the protrusion 30 and the inner wall of the expansion region 21, allowing fluid to flow through this gap. The protrusion 30 can be located at the center of the expansion region 21 or offset to one side. The protrusion 30 can divide the expansion region 21 into multiple flow channel branches or form only a narrow flow channel.

[0022] When assembling a fuel cell using the technical solution of this invention, the protrusion 30 occupies a portion of the space in the expansion region 21 and provides support for the membrane electrode assembly (MEA). Therefore, the protrusion 30 reduces the depth to which the MEA is embedded in the expansion region 21, preventing the MEA from blocking the flow channels and ensuring smooth gas flow, thus guaranteeing the fuel cell's performance. Furthermore, the protrusion 30 has a simple structure, facilitating the processing and shaping of the fuel cell electrode plates.

[0023] Specifically, the expansion zone 21 has a first inner sidewall and a second inner sidewall disposed opposite to each other, and the protrusion 30 has a first protruding sidewall and a second protruding sidewall disposed opposite to each other. The first inner sidewall is disposed opposite to the first protruding sidewall, and the second inner sidewall is disposed opposite to the second protruding sidewall. The first inner sidewall and the first protruding sidewall are equally spaced, and / or the second inner sidewall and the second protruding sidewall are equally spaced. In this embodiment, the first inner sidewall and the first protruding sidewall are equally spaced, and the second inner sidewall and the second protruding sidewall are equally spaced. The above arrangement can ensure the smoothness and stability of gas flow within the expansion zone 21, thereby ensuring the working performance of the fuel cell. Furthermore, the protrusion 30 has a simple structure, which is convenient for design and manufacturing.

[0024] Furthermore, the distance between the first inner sidewall and the first protruding sidewall is equal to the distance between the second inner sidewall and the second protruding sidewall. This arrangement allows the protrusion 30 to divide the expansion region 21 into two symmetrically arranged parts. When gas flows from the contraction region 22 to the expansion region 21, the gas in the contraction region 22 can be evenly distributed into the two parts of the expansion region 21, ensuring the stability and smoothness of gas flow. Similarly, this arrangement also ensures the smoothness of gas flow from the two parts of the expansion region 21 into the contraction region 22, guaranteeing the working performance of the fuel cell.

[0025] Specifically, the contraction zone 22 has a third inner sidewall and a fourth inner sidewall disposed opposite to each other. The distance between the third inner sidewall and the fourth inner sidewall is less than the distance between the first inner sidewall and the first protruding sidewall, and / or the distance between the third inner sidewall and the fourth inner sidewall is less than the distance between the second protruding sidewall and the second inner sidewall. In this embodiment, the distance between the third inner sidewall and the fourth inner sidewall is less than the distance between the first inner sidewall and the first protruding sidewall, and the distance between the third inner sidewall and the fourth inner sidewall is less than the distance between the second protruding sidewall and the second inner sidewall. This arrangement creates a difference between the cross-sectional areas of the two parts of the expansion zone 21 and the cross-sectional areas between the third and fourth inner sidewalls, thereby causing changes in the concentration and pressure of the gas flowing through the flow channel, increasing the gas pressure gradient, enhancing the gas transmission effect, and ensuring smooth gas delivery. Furthermore, the enhanced gas transmission effect can guide water within the flow channel, promoting the movement of water droplets through airflow and improving drainage capacity.

[0026] In this embodiment, the flow channel has a central axis located between two adjacent pole ridges 10. The central axis extends in the same direction as the fuel cell pole plates, and the two adjacent pole ridges 10 are symmetrically arranged relative to the central axis. This arrangement facilitates the formation of the flow channel structure, ensures the consistency of gas flow within the flow channel, and thus improves the performance of the fuel cell.

[0027] The central axis divides the flow channel into two symmetrically arranged branch channels. The branch channels can be configured with alternating variable diameter zones and constant diameter zones. In the flow channel, the two variable diameter zones form an expansion zone 21, and the two constant diameter zones form a contraction zone 22. The cross-section of the variable diameter zone can be set to an arc shape, a triangle, or a trapezoid, and the cross-section of the contraction zone 22 can be set to a rectangle.

[0028] In this embodiment, the pole ridge 10 has a corrugated structure along its extension direction. This design ensures that the interior of the flow channel is entirely arc-shaped along the gas flow direction, reducing resistance to the gas and thus guaranteeing smooth gas flow. Furthermore, the corrugated structure improves water flow, preventing water generated during fuel cell operation from accumulating in the flow channel.

[0029] Furthermore, the surface of the protrusion 30 is curved. This design reduces the resistance of the protrusion 30 to the gas, ensuring smooth gas flow. Moreover, by making the surface of the protrusion 30 curved, it allows the protrusion 30 to fit the pole ridge 10, ensuring equal spacing between the first protruding sidewall of the protrusion 30 and the first inner sidewall of the pole ridge 10, and between the second protruding sidewall of the protrusion 30 and the second inner wall of the pole ridge 10. In this embodiment, the cross-section of the protrusion 30 is elliptical, and the major axis direction of the protrusion 30 is the same as the extension direction of the flow channel.

[0030] Specifically, the height of the protrusion 30 is between 0.9 and 1.1 times the height of the ridge 10. When the height of the protrusion 30 is less than 0.9 times the height of the ridge 10, the protrusion 30 provides poor support for the membrane electrode assembly (MEA) and cannot effectively prevent the MEA from embedding into the expansion region 21. In a fuel cell unit, two fuel cell plates are arranged opposite each other, and the MEA is located between the two fuel cell plates. During fuel cell assembly, the protrusions 30 on the two fuel cell plates come into contact. When the height of the protrusion 30 is greater than 1.1 times the height of the ridge 10, there may be a problem of poor sealing in the fuel cell unit assembly, reducing the performance of the fuel cell. Furthermore, the contact area between the protrusions 30 on the two fuel cell plates is small, resulting in high pressure, which may cause damage to the protrusion 30 or even damage to the fuel cell plates. Therefore, setting the height of the protrusion 30 between 0.9 and 1.1 times the height of the pole ridge 10 ensures both the support effect of the protrusion 30 on the membrane electrode, reduces the depth of the membrane electrode embedded in the expansion region 21, ensures smooth flow of gas and water, and maintains the structural strength of the fuel cell plate. The height of the protrusion 30 can be 0.9 or 1.1 times the height of the pole ridge 10; in this embodiment, the height of the protrusion 30 is equal to the height of the pole ridge 10.

[0031] Another embodiment of the present invention provides a bipolar plate comprising two fuel cell plates welded together as described above.

[0032] Another embodiment of the present invention provides a fuel cell including the fuel cell plates described above.

[0033] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0034] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0035] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0036] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0037] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0038] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A fuel cell electrode plate, characterized in that, The fuel cell electrode plate has multiple spaced-apart ridges (10) on one side, and a flow channel is formed between two adjacent ridges (10). The flow channel includes an expansion area (21) and a contraction area (22) that are interconnected. The expansion area (21) and the contraction area (22) are alternately arranged along the extension direction of the flow channel. The flow area of ​​the expansion area (21) is larger than the flow area of ​​the contraction area (22). The fuel cell electrode plate is also provided with a protrusion (30). The protrusion (30) is located in the expansion area (21), and there is a gap between the protrusion (30) and the inner wall of the expansion area (21). The expansion zone (21) has a first inner sidewall and a second inner sidewall that are disposed opposite to each other, and the protrusion (30) has a first protruding sidewall and a second protruding sidewall that are disposed opposite to each other. The first inner sidewall is disposed opposite to the first protruding sidewall, the second inner sidewall is disposed opposite to the second protruding sidewall, the first inner sidewall and the first protruding sidewall are disposed at equal intervals, and / or the second inner sidewall and the second protruding sidewall are disposed at equal intervals. The distance between the first inner sidewall and the first protruding sidewall is equal to the distance between the second inner sidewall and the second protruding sidewall; The contraction zone (22) has a third inner sidewall and a fourth inner sidewall disposed opposite to each other, the distance between the third inner sidewall and the fourth inner sidewall being less than the distance between the first inner sidewall and the first protruding sidewall, and / or the distance between the third inner sidewall and the fourth inner sidewall being less than the distance between the second protruding sidewall and the second inner sidewall.

2. The fuel cell electrode plate according to claim 1, characterized in that, The flow channel has a central axis, which is located between two adjacent pole ridges (10). The extension direction of the central axis is the same as the extension direction of the fuel cell plate. The two adjacent pole ridges (10) are symmetrically arranged relative to the central axis.

3. The fuel cell electrode plate according to claim 1, characterized in that, The pole ridge (10) has a corrugated structure along its extension direction.

4. The fuel cell electrode plate according to claim 3, characterized in that, The surface of the protrusion (30) is an arc surface.

5. The fuel cell electrode plate according to claim 1, characterized in that, The height of the protrusion (30) is between 0.9 and 1.1 times the height of the pole ridge (10).

6. A bipolar plate, characterized in that, The bipolar plate comprises two fuel cell plates welded together as described in any one of claims 1 to 5.

7. A fuel cell, characterized in that, The fuel cell includes the fuel cell plate as described in any one of claims 1 to 5.

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