A bipolar plate and a stack

Abstract

The application discloses a bipolar plate and a fuel cell stack, and belongs to the technical field of fuel cells. The bipolar plate has a first surface and a second surface, and the first surface and the second surface are located on two sides of the thickness direction of the bipolar plate. The bipolar plate is raised to the side where the first surface is located, so that a first main ridge located in an active area and a first distribution protrusion located in a distribution area are formed on the first surface, and a first main groove corresponding to the first main ridge and a first distribution groove corresponding to the first distribution protrusion are formed on the second surface. The top surface of the first distribution protrusion is higher than the top surface of the first main ridge. By making the top surface of the first distribution protrusion higher than the top surface of the first main ridge, the bipolar plate can be matched with a membrane electrode assembly. The gap between the distribution area of the bipolar plate and the membrane electrode assembly can be increased, that is, the space of the gas distribution flow field is increased, and the depth of the first distribution groove is increased, the space of the cooling liquid distribution flow field is increased, and the uniformity of gas and cooling liquid distribution is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and more particularly to a bipolar plate and a fuel cell stack. Background Technology

[0002] During fuel cell operation, hydrogen enters the hydrogen flow field through the hydrogen inlet manifold, is distributed into the main hydrogen flow field via the hydrogen flow field distribution area, diffuses into the gas diffusion layer, and reaches the surface of the anode catalytic electrode. Hydrogen ions then pass through the proton exchange membrane to reach the surface of the cathode catalytic electrode, while electrons pass through the bipolar plates to reach the cathode of the adjacent single cell. Similarly, air enters the air flow field through the air inlet manifold, is distributed into the main air flow field via the air flow field distribution area, diffuses into the gas diffusion layer, and reaches the surface of the cathode catalytic electrode to carry out electrochemical reactions. Reaction products and unreacted working media are collected by the flow field and discharged from the bipolar plates, and further discharged from the fuel cell through the exhaust manifold. Coolant enters the coolant chamber between the bipolar plates through the coolant inlet manifold, is distributed into the main coolant flow field via the coolant flow field distribution area, exchanges heat with the bipolar plates at the location where the electrochemical reaction occurs, and then carries the heat away from the fuel cell.

[0003] During fuel cell operation, a uniform electrochemical reaction and temperature distribution should occur in the active zone. Uneven water, thermal, and electrical conditions can cause extreme operating conditions such as flooding and reverse polarity, which can severely damage the fuel cell and drastically reduce its lifespan. To ensure normal operation, a distribution zone is typically required to uniformly distribute the fluid, and its importance is self-evident.

[0004] To improve the performance of single cells, most bipolar plate designs currently concentrate the three cavities on both sides of the flow field length direction. This results in the "small inlet, large outlet" shape of the three distribution regions and the overlapping and squeezing of the three distribution regions in the narrow thickness direction. This leads to an increase in the pressure drop of the reactive gas distribution flow field and the coolant distribution flow field, and further increases the difficulty of distributing the reactive gas and coolant. Summary of the Invention

[0005] The purpose of this invention is to provide a bipolar plate and fuel cell stack that can increase the space of the gas distribution flow field and the coolant distribution flow field, thereby reducing the pressure drop of the gas distribution flow field and the coolant distribution flow field and improving the uniformity of gas and coolant distribution.

[0006] To achieve the above objectives, the following technical solution is provided:

[0007] On one hand, a bipolar plate is provided, comprising two fixedly connected monopolar plates; the monopolar plate includes an active region, a manifold region, and a distribution region located between the active region and the manifold region;

[0008] The monopolar plate has a first surface and a second surface, the first surface and the second surface are respectively located on both sides of the thickness direction of the monopolar plate. The monopolar plate protrudes towards the side where the first surface is located to form a first main ridge located in the active region and a first distribution protrusion located in the distribution region on the first surface, and forms a first main groove corresponding to the first main ridge and a first distribution groove corresponding to the first distribution protrusion on the second surface.

[0009] The top surface of the first distribution protrusion is higher than the top surface of the first main ridge.

[0010] As an alternative to the bipolar plate, the first surface includes a first active surface located in the active region and a first distribution surface located in the distribution region, the first main ridge protruding from the first active surface and the first distribution protrusion protruding from the first distribution surface;

[0011] The first dispensing surface is higher than the first active surface.

[0012] As an alternative to the bipolar plate, the first distribution protrusion includes a plurality of spaced-apart first distribution ridges;

[0013] The first distribution protrusion also includes a plurality of first distribution protrusions spaced apart;

[0014] Each of the two adjacent first distribution ridges is provided with a first distribution protrusion.

[0015] As an alternative to the bipolar plate, the arrangement density of the plurality of first distribution ridges on one of the monopolar plates is different from the arrangement density of the plurality of first distribution ridges on the other monopolar plate; and / or,

[0016] The arrangement density of a plurality of first distribution bumps on one of the monopolar plates is different from the arrangement density of a plurality of first distribution bumps on the other monopolar plate.

[0017] As an alternative to the bipolar plate, the height of the first distribution ridge is equal to the height of the first distribution protrusion.

[0018] As an alternative to the bipolar plate, the monopolar plate protrudes towards the side where the second surface is located to form a second distribution protrusion located in the distribution area on the second surface, and a second distribution groove corresponding to the second distribution protrusion is formed on the first surface.

[0019] The second distribution protrusion of one of the monopolar plates can abut against the second surface of the other monopolar plate; or, the second distribution protrusion of one of the monopolar plates can abut against the second distribution protrusion of the other monopolar plate.

[0020] As an alternative to the bipolar plate, the second distribution protrusion includes a plurality of spaced second distribution protrusions.

[0021] As an alternative to bipolar plates, the monopolar plate is a plate with uniform thickness.

[0022] On the other hand, a fuel cell stack is provided, including a bipolar plate as described in any of the preceding claims.

[0023] As an optional solution for the fuel cell stack, membrane electrode assemblies are provided on both sides of the bipolar plate. The membrane electrode assembly includes a membrane electrode active component and a membrane electrode frame, and the thickness of the membrane electrode frame is less than the thickness of the membrane electrode active component.

[0024] The first main ridge abuts against the membrane electrode active component of the corresponding membrane electrode assembly, and the first distribution protrusion abuts against the membrane electrode frame of the corresponding membrane electrode assembly.

[0025] As an alternative to the stack, when the bipolar plate is assembled with the membrane electrode assembly to form the stack, the height difference between the first main ridge and the first distribution protrusion is half the thickness difference between the membrane electrode active component and the membrane electrode frame.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] The bipolar plate of the present invention, by making the top surface of the first distribution protrusion higher than the top surface of the first main ridge, can be matched with the membrane electrode assembly. This not only increases the gap between the distribution area of ​​the monopolar plate and the membrane electrode assembly, thus increasing the space of the gas distribution flow field, but also effectively increases the depth of the first distribution groove, thereby increasing the space of the coolant distribution flow field. This achieves the purpose of reducing the pressure drop of the gas distribution flow field and the coolant distribution flow field, and improving the uniformity of gas and coolant distribution.

[0028] The fuel cell stack of the present invention, by applying the above-mentioned bipolar plates, reduces the pressure drop in the gas distribution flow field and the coolant distribution flow field, thereby improving the uniformity of gas and coolant distribution. Attached Figure Description

[0029] Figure 1 This is a schematic diagram showing the fit between the bipolar plate and the membrane electrode assembly along the length of the bipolar plate in an embodiment of the present invention;

[0030] Figure 2 This is a schematic diagram showing the relationship between the distribution area of ​​the bipolar plate and the membrane electrode frame along the width direction of the bipolar plate in an embodiment of the present invention.

[0031] Figure 3 This is a schematic diagram showing the relationship between the active region of the bipolar plate and the active component of the membrane electrode along the width direction of the bipolar plate in an embodiment of the present invention.

[0032] Figure 4 This is a schematic diagram of the structure of the first surface of the monopolar plate in an embodiment of the present invention;

[0033] Figure 5 for Figure 4 Enlarged view of part A;

[0034] Figure 6 This is a schematic diagram of the structure of the second surface of the monopolar plate in an embodiment of the present invention;

[0035] Figure 7 for Figure 6 Enlarged view of part B.

[0036] Figure label:

[0037] 1. Monopolar plate; 1a. Active region; 1b. Split region; 1c. Distribution region; 11. First surface; 111. First main ridge; 112. First distribution protrusion; 1121. First distribution ridge; 1122. First distribution bump; 113. Second distribution groove; 114. Second main groove; 12. Second surface; 121. Second distribution protrusion; 122. Second main ridge; 123. First main groove; 124. First distribution groove;

[0038] 2. Membrane electrode assembly; 21. Membrane electrode active component; 22. Membrane electrode frame;

[0039] 101. Main gas flow field; 102. Gas distribution flow field; 201. Main coolant flow field; 202. Coolant distribution flow field. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, 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 components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0043] In the description of this invention, it should be noted that the terms "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are used only for the convenience of describing the invention and for simplifying the description, and 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. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0047] like Figure 1-7 As shown, this embodiment provides a bipolar plate and a fuel cell stack. The fuel cell stack includes a plurality of bipolar plates and membrane electrode assemblies 2 arranged corresponding to the plurality of bipolar plates. Specifically, each bipolar plate has membrane electrode assemblies 2 on both sides, that is, a bipolar plate and the membrane electrode assemblies 2 on both sides form a single cell. The fuel cell stack includes a plurality of stacked single cells.

[0048] The bipolar plate includes two monopolar plates 1. The two monopolar plates 1 are fixedly connected on opposite sides, forming a coolant flow field. The opposite sides of the two monopolar plates 1 are respectively in contact with two membrane electrode assemblies 2, forming a gas flow field between the monopolar plate 1 and the corresponding membrane electrode assembly 2. One of the two monopolar plates 1 serves as the anode plate, and the other as the cathode plate. Specifically, the gas flow field between the anode plate and the corresponding membrane electrode assembly 2 is the anode gas flow field, and the gas flow field between the cathode plate and the corresponding membrane electrode assembly 2 is the cathode flow field.

[0049] Furthermore, the monopolar plate 1 includes an active region 1a, a manifold region 1b, and a distribution region 1c located between the active region 1a and the manifold region 1b. The gas flow field includes a main gas flow field 101 located in the active region 1a and a gas distribution flow field 102 located in the distribution region 1c. The coolant flow field includes a main coolant flow field 201 located in the active region 1a and a coolant distribution flow field 202 located in the distribution region 1c. The manifold region 1b is provided with a gas inlet, a gas outlet, a coolant inlet, and a coolant outlet. In this embodiment, there are two manifold regions 1b and two distribution regions 1c. The two manifold regions 1b are located at both ends of the length direction of the monopolar plate 1, and the active region 1a is located in the middle of the length direction of the monopolar plate 1. A distribution region 1c is provided between each manifold region 1b and the active region 1a.

[0050] The reactant gas enters the gas distribution flow field 102 through the gas inlet, and after being distributed by the gas distribution flow field 102, it enters the main gas flow field 101. The reaction products and the working medium that did not participate in the reaction are collected by the gas flow field and discharged through the gas outlet. The coolant enters the coolant distribution flow field 202 through the coolant inlet, and after being distributed by the coolant distribution flow field 202, it enters the main coolant flow field 201. It exchanges heat with the location where the electrochemical reaction occurs through the bipolar plate, and then is discharged through the coolant outlet, carrying the heat away from the fuel cell.

[0051] In the existing technology, the height of the gas distribution flow field is almost equal to the height of the mainstream gas flow field, and the height of the coolant distribution flow field is almost equal to the height of the mainstream coolant flow field. This results in a large pressure drop in the gas distribution flow field and the coolant distribution flow field, poor uniformity of gas and liquid distribution, high additional losses in the fuel cell system, and reduced fuel cell output power.

[0052] To address the aforementioned issues, in this embodiment, the monopolar plate 1 has a first surface 11 and a second surface 12. The first surface 11 and the second surface 12 are located on opposite sides of the thickness direction of the monopolar plate 1. The monopolar plate 1 protrudes towards the side where the first surface 11 is located, thereby forming a first main ridge 111 located in the active region 1a and a first distribution protrusion 112 located in the distribution region 1c on the first surface 11. A first main groove 123 corresponding to the first main ridge 111 and a first distribution groove 124 corresponding to the first distribution protrusion 112 are formed on the second surface 12. The top surface of the first distribution protrusion 112 is higher than the top surface of the first main ridge 111.

[0053] By making the top surface of the first distribution protrusion 112 higher than the top surface of the first main ridge 111, it can be matched with the membrane electrode assembly 2. This not only increases the gap between the distribution area 1c of the monopolar plate 1 and the membrane electrode assembly 2, thus increasing the space of the gas distribution flow field 102, but also increases the depth of the first distribution groove 124, which has the effect of increasing the space of the coolant distribution flow field 202. This achieves the purpose of reducing the pressure drop of the gas distribution flow field 102 and the coolant distribution flow field 202, and improving the uniformity of gas and coolant distribution.

[0054] It should be noted that simply increasing the depth of the first distribution groove 124 to increase the space of the coolant distribution flow field 202 has limited effect. Furthermore, the first surface 11 includes a first active surface located in the active region 1a and a first distribution surface located in the distribution region 1c. A first main ridge 111 protrudes from the first active surface, and a first distribution protrusion 112 protrudes from the first distribution surface; the first distribution surface is higher than the first active surface. This arrangement effectively increases the distance between the distribution regions 1c of the two single-plate 1, significantly increasing the space of the coolant distribution flow field 202 and greatly improving the uniformity of coolant distribution.

[0055] The membrane electrode assembly 2 includes a membrane electrode active component 21 and a membrane electrode frame 22 connected to the membrane electrode active component 21. The thickness of the membrane electrode frame 22 is less than the thickness of the membrane electrode active component 21. It can be understood that the thickness of the portion of the membrane electrode assembly 2 corresponding to the active region 1a of the monopolar plate 1 is the thickness of the membrane electrode active component 21, while the thickness of the portion of the membrane electrode assembly 2 corresponding to the distribution region 1c of the monopolar plate 1 is the thickness of the membrane electrode frame 22. In other words, the membrane electrode active component 21 is only provided in the active region 1a of the monopolar plate 1 to ensure the normal progress of the electrochemical reaction, while only the membrane electrode frame 22 is provided in the distribution region 1c of the monopolar plate 1 to fix the membrane electrode assembly 2, which has the effect of reducing costs.

[0056] In this embodiment, the first main ridge 111 abuts against the membrane electrode active component 21 to form the aforementioned gas mainstream flow field 101, and the first distribution protrusion 112 abuts against the membrane electrode frame 22 to form the aforementioned gas distribution flow field 102. Taking into full account the structural features and matching relationship between the bipolar plate and the membrane electrode assembly 2, the gap between the bipolar plate and the membrane electrode assembly 2 is reasonably divided and utilized, without increasing the total space occupied by the bipolar plate and the membrane electrode assembly 2.

[0057] Furthermore, since there is a thickness difference between the membrane electrode frame 22 and the membrane electrode active component 21, in order to compensate for the gap between the membrane electrode assembly and the distribution area of ​​the monopolar plate, the gas diffusion layer of the membrane electrode assembly needs to be set as an irregular shape to fill the gap between the membrane electrode assembly and the distribution area of ​​the monopolar plate, which increases the processing difficulty and assembly difficulty of the gas diffusion layer and increases the cost.

[0058] In this embodiment, by making the top surface of the first distribution protrusion 112 higher than the top surface of the first main ridge 111, and by making the first main ridge 111 abut against the membrane electrode active component 21 and the first distribution protrusion 112 abut against the membrane electrode frame 22, the gas diffusion layer of the membrane electrode assembly 2 can be set as a conventional rectangle, which greatly improves the material utilization rate of the gas diffusion layer, reduces the processing and assembly difficulty of the gas diffusion layer, and reduces costs.

[0059] Optionally, when the bipolar plate and the membrane electrode assembly 2 are assembled to form a stack, in other words, the membrane electrode assembly 2 has been compressed, and the height difference between the first main ridge 111 and the first distribution protrusion 112 is half the thickness difference between the membrane electrode active component 21 and the membrane electrode frame 22. In other words, the height difference between the first main ridge 111 and the first distribution protrusion 112 is half the thickness difference between the portion of the membrane electrode assembly 2 corresponding to the active region 1a of the monopolar plate 1 and the portion of the membrane electrode assembly 2 corresponding to the distribution region 1c of the monopolar plate 1. While ensuring that the total space occupied by the bipolar plate and the membrane electrode assembly 2 is not increased, the gap between the bipolar plate and the membrane electrode assembly 2 is further fully utilized to maximize the gas distribution flow field 102 and the coolant distribution flow field 202.

[0060] In this embodiment, the first distribution protrusion 112 includes a plurality of spaced-apart first distribution ridges 1121 and a plurality of spaced-apart first distribution protrusions 1122, with a first distribution protrusion 1122 provided between each adjacent pair of first distribution ridges 1121. It should be noted that the first distribution ridges 1121 extend to a certain length to form a gas distribution channel between adjacent pairs of first distribution ridges 1121; the first distribution protrusions 1122 are smaller in length than the first distribution ridges 1121 and are provided between adjacent pairs of first distribution ridges 1121, which can further promote uniform gas distribution in the gas distribution channel.

[0061] It should be noted that the several first distribution ridges 1121 are spaced apart, which adopts the differential gas distribution method commonly used in the art; the several first distribution protrusions 1122 are spaced apart, which adopts the lattice gas distribution method commonly used in the art. In this embodiment, a first distribution protrusion 1122 is provided between each two adjacent first distribution ridges 1121. Combining the differential gas distribution method with the lattice gas distribution method not only improves the support strength of the first distribution protrusions 112 to the membrane electrode assembly 2, but also improves the uniformity of gas distribution.

[0062] Of course, in other embodiments, the first distribution protrusion 112 may only include the first distribution ridge 1121, that is, only adopt the differential gas distribution method; or it may only include the first distribution protrusion 1122, that is, only adopt the dot matrix gas distribution method.

[0063] For example, the cross-section of the first distribution protrusion 112 can be circular, elliptical, rectangular, parallelogram or trapezoidal, and of course it can also be other shapes, such as flower shape, etc., which are not limited here; the cross-section of the first distribution protrusion 112 is a cross-section parallel to the first surface 11.

[0064] Optionally, the height of the first distribution ridge 1121 is equal to the height of the first distribution protrusion 1122, so that the first distribution ridge 1121 and the first distribution protrusion 1122 can provide the same support force for the membrane electrode assembly 2, ensuring the support stability of the membrane electrode assembly 2.

[0065] In this embodiment, the arrangement density of the plurality of first distribution ridges 1121 on the anode plate is different from that on the cathode plate; the arrangement density of the plurality of first distribution protrusions 1122 on the anode plate is different from that on the cathode plate, thereby allowing for the separate control of the uniformity of the distribution of the anode reactant gas and the cathode reactant gas, matching the characteristics of the anode reactant gas and the cathode reactant gas, which helps to improve the performance of the fuel cell.

[0066] Of course, in other embodiments, the arrangement density of the plurality of first distribution ridges 1121 on the anode plate may be different from that on the cathode plate; the arrangement density of the plurality of first distribution protrusions 1122 on the anode plate may be the same as that on the cathode plate. Alternatively, the arrangement density of the plurality of first distribution ridges 1121 on the anode plate may be the same as that on the cathode plate; the arrangement density of the plurality of first distribution protrusions 1122 on the anode plate may be different from that on the cathode plate.

[0067] Optionally, the monopolar plate 1 protrudes towards the side where the second surface 12 is located, forming a second distribution protrusion 121 located in the distribution area 1c on the second surface 12, and forming a second distribution groove 113 corresponding to the second distribution protrusion 121 on the first surface 11; the second distribution protrusion 121 of one monopolar plate 1 can abut against the second surface 12 of the other monopolar plate 1; or, the second distribution protrusion 121 of one monopolar plate 1 can abut against the second distribution protrusion 121 of the other monopolar plate 1. This allows coolant to be distributed simultaneously through the second distribution protrusions 121 of the two monopolar plates 1, improving the uniformity of coolant distribution; at the same time, this arrangement allows the second distribution protrusion 121 of one monopolar plate 1 to support the other monopolar plate 1, ensuring the strength of the monopolar plate 1 and preventing deformation.

[0068] Optionally, the second distribution protrusion 121 includes a plurality of spaced-apart second distribution protrusions. In this embodiment, only a dot-matrix coolant distribution method is used in the coolant distribution flow field 202.

[0069] For example, the cross-section of the second distribution protrusion 121 can be circular, elliptical, rectangular, parallelogram or trapezoidal, and of course it can also be other shapes, such as flower shape, etc., which are not limited here; the cross-section of the second distribution protrusion 121 is a cross-section parallel to the second surface 12.

[0070] Optionally, the monopolar plate 1 further protrudes towards the side where the second surface 12 is located, so as to form a second main ridge 122 located in the active region 1a on the second surface 12, and a second main groove 114 corresponding to the second main ridge 122 is formed on the first surface 11; the second main ridge 122 of one monopolar plate 1 can abut against the second main ridge 122 of the other monopolar plate 1; or, the second main ridge 122 of one monopolar plate 1 can abut against the second surface 12 of the other monopolar plate 1, so as to support the other monopolar plate 1 through the second main ridge 122 of one monopolar plate 1, thereby improving the strength of the monopolar plate 1.

[0071] It should be noted that in this embodiment, the monopolar plate 1 is a plate with uniform thickness, and all ridges and protrusions on the monopolar plate 1 are formed by a stamping process. This design improves the manufacturability of the monopolar plate 1, makes it easy to manufacture, and reduces costs.

[0072] Furthermore, since the single plate 1 is a plate with uniform thickness, the second surfaces 12 of the two single plate 1 distribution areas 1c are non-adherent surfaces, that is, a larger coolant distribution flow field 202 is formed between the second surfaces 12 of the two single plate 1 distribution areas 1c, which further improves the uniformity of coolant distribution.

[0073] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A bipolar plate comprising two fixedly connected monopolar plates (1); the monopolar plate (1) comprising an active region (1a), a manifold region (1b), and a distribution region (1c) located between the active region (1a) and the manifold region (1b); Its features are, The monopolar plate (1) has a first surface (11) and a second surface (12), the first surface (11) and the second surface (12) being located on opposite sides of the thickness direction of the monopolar plate (1), the monopolar plate (1) protruding towards the side where the first surface (11) is located, to form a first main ridge (111) located in the active region (1a) and a first distribution protrusion (112) located in the distribution region (1c) on the first surface (11), and to form a first main groove (123) corresponding to the first main ridge (111) and a first distribution groove (124) corresponding to the first distribution protrusion (112) on the second surface (12); The top surface of the first distribution protrusion (112) is higher than the top surface of the first main ridge (111); The single plate (1) protrudes towards the side where the second surface (12) is located, so as to form a second distribution protrusion (121) located in the distribution area (1c) on the second surface (12), and a second distribution groove (113) corresponding to the second distribution protrusion (121) is formed on the first surface (11); The second distribution protrusion (121) of one of the monopolar plates (1) can abut against the second surface (12) of the other monopolar plate (1); or, the second distribution protrusion (121) of one of the monopolar plates (1) can abut against the second distribution protrusion (121) of the other monopolar plate (1), and the second distribution protrusions (121) of the two monopolar plates (1) can simultaneously distribute coolant; The monopolar plate (1) also protrudes towards the side where the second surface (12) is located, so as to form a second main ridge (122) located in the active region (1a) on the second surface (12) and a second main groove (114) corresponding to the second main ridge (122) on the first surface (11); the second main ridge (122) of one of the monopolar plates (1) can abut against the second main ridge (122) of the other monopolar plate (1); or, the second main ridge (122) of one of the monopolar plates (1) can abut against the second surface (12) of the other monopolar plate (1).

2. The bipolar plate according to claim 1, characterized in that, The first surface (11) includes a first active surface located in the active region (1a) and a first distribution surface located in the distribution region (1c), the first main ridge (111) protrudes from the first active surface, and the first distribution protrusion (112) protrudes from the first distribution surface; The first dispensing surface is higher than the first active surface.

3. The bipolar plate according to claim 1, characterized in that, The first distribution protrusion (112) includes a plurality of spaced-apart first distribution ridges (1121); The first distribution protrusion (112) further includes a plurality of spaced-apart first distribution protrusions (1122); Each of the two adjacent first distribution ridges (1121) is provided with a first distribution protrusion (1122).

4. The bipolar plate according to claim 3, characterized in that, The arrangement density of the plurality of first distribution ridges (1121) on one of the monopole plates (1) is different from the arrangement density of the plurality of first distribution ridges (1121) on the other monopole plate (1); and / or, The arrangement density of a plurality of first distribution bumps (1122) on one of the monopolar plates (1) is different from the arrangement density of a plurality of first distribution bumps (1122) on the other monopolar plate (1).

5. The bipolar plate according to claim 3, characterized in that, The height of the first distribution ridge (1121) is equal to the height of the first distribution protrusion (1122).

6. The bipolar plate according to claim 1, characterized in that, The second distribution protrusion (121) includes a plurality of spaced second distribution protrusions.

7. The bipolar plate according to any one of claims 1-6, characterized in that, The single-pole plate (1) is a plate with uniform thickness.

8. A fuel cell stack, characterized in that, Includes the bipolar plate as described in any one of claims 1-7.

9. The fuel cell stack according to claim 8, characterized in that, Both sides of the bipolar plate are provided with membrane electrode assemblies (2), and the membrane electrode assembly (2) includes a membrane electrode active component (21) and a membrane electrode frame (22). The thickness of the membrane electrode frame (22) is less than the thickness of the membrane electrode active component (21). The first main ridge (111) abuts against the membrane electrode active component (21) of the corresponding membrane electrode assembly (2), and the first distribution protrusion (112) abuts against the membrane electrode frame (22) of the corresponding membrane electrode assembly (2).

10. The fuel cell stack according to claim 9, characterized in that, When the bipolar plate is assembled with the membrane electrode assembly (2) to form a stack, the height difference between the first main ridge (111) and the first distribution protrusion (112) is half the thickness difference between the membrane electrode active component (21) and the membrane electrode frame (22).

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