Monopole plate, monocell and fuel cell stack

Abstract

The utility model relates to a monopolar plate, a monocell and a fuel cell stack. The polar plate comprises a gas manifold opening and a flow field area, a circle of hollow gas guide boss is arranged around the gas manifold opening, a plurality of gas guide through holes are formed in the inner circle of the gas guide boss, a plurality of gas flow channels are connected to the outer circle of the gas guide boss, and the gas guide boss is communicated with the gas manifold opening and the flow field area through the gas guide through holes and the gas flow channels. The single pole plate is provided with the gas guide boss of the hollow structure, the gas guide boss, the gas guide through hole and the gas flow channel form a gas gap bridge area structure with a cavity, working gas can be fully gathered and drained, inlet and outlet gas guiding is achieved, meanwhile, the gas guide boss is of a protruding structure, the sealing design is more convenient and reliable, and the sealing effect is better. And the gas guide through holes and the gas flow channels can be flexibly arranged, so that uniform gas distribution is facilitated, and the reaction power generation effect is improved. In addition, the monopolar plate also overcomes the limitation of membrane electrode punching on the frame, so that the design freedom degree of the frame of the membrane electrode is recovered.

Description

Technical Field

[0001] The present application relates to the field of fuel cell technology, and in particular to a monopolar plate, a single cell and a fuel cell stack. Background Art

[0002] A fuel cell cell consists of a cathode plate, a membrane electrode (MEA), and an anode plate. The three are assembled together by bonding to form a single cell assembly, and the single cells are stacked back and forth to form a fuel cell stack. Among them, reaction gases such as hydrogen and air enter the flow channel through the bridge area at the manifold mouth to enter the anode and cathode flow fields for electrochemical reactions to generate electricity. However, since the single cell adopts a unipolar plate structure, it is impossible to use the traditional bridge area design like the bipolar plate (direct punching of the unipolar plate structure will cause the air cavity and the water cavity to be connected). Therefore, the current solution is to punch holes in the MEA frame to form a gas flow channel inlet to assume the function of the plate bridge area (such as Figures 1 to 3 However, doing so will result in sealing risks and gas distribution problems, and because the membrane electrode frame serves as the bridge area, it will also affect the thickness matching freedom of the membrane electrode frame. Utility Model Content

[0003] The present application provides a monopolar plate, a single cell and a fuel cell stack to solve the problem in the prior art that the single cell structure needs to punch holes in the membrane electrode frame to form a gas flow channel inlet, which leads to risks in sealing and gas distribution and affects the freedom of the membrane electrode frame thickness.

[0004] According to a monopolar plate provided in the present application, the monopolar plate includes: a gas manifold port and a flow field area, a circle of hollow gas guide bosses are arranged around the gas manifold port, the inner circle of the gas guide bosses are provided with a plurality of gas guide holes, the outer circle of the gas guide bosses are connected with a plurality of gas flow channels, and the gas guide bosses are connected to the gas manifold port and the flow field area through the gas guide holes and the gas flow channels.

[0005] In some embodiments, a plurality of air-conducting through holes are opened in the inner circle of the air-conducting boss, and the plurality of air-conducting through holes are evenly distributed.

[0006] In some embodiments, the gas flow channel is disposed on a side of the gas guide boss close to the flow field area, and a plurality of gas flow channels are provided, and outlet ends of the plurality of gas flow channels are connected to the flow field area.

[0007] In some embodiments, a plurality of circumferentially distributed point-shaped support structures are further provided on the air-guiding boss, and the point-shaped support structures are staggered with the air-guiding through holes.

[0008] In some embodiments, the point-shaped support structure is a blind hole that is disposed on the top of the air guide boss and is recessed inward.

[0009] In some embodiments, the blind hole is disposed at a central position on the top of the air guiding boss, and the number of the blind holes on a side of the air guiding boss close to the flow field region is sparse compared to other sides.

[0010] In some embodiments, a sealing ring is disposed on the top of the air guide boss, and a portion of the sealing ring is embedded in the blind hole.

[0011] In some embodiments, the monopolar plate is a cathode plate or an anode plate; and the gas-conducting boss is disposed around a gas manifold port for conveying air or hydrogen.

[0012] According to another aspect of the present application, a single cell is provided, which includes a membrane electrode and a monopolar plate as described above; the monopolar plate includes an anode plate and a cathode plate, the membrane electrode is clamped between the anode plate and the cathode plate, and the gas guide boss of the anode plate and the gas guide boss of the cathode plate respectively form a gas guide cavity between the membrane electrode.

[0013] According to another aspect of the present application, a fuel cell stack is provided. The fuel cell stack includes a plurality of stacked and assembled single cells as described above.

[0014] The technical solution of the present application is to set a circle of hollow gas-guiding bosses around the gas manifold port of the monopolar plate, the inner circle of the gas-guiding bosses is provided with a plurality of gas-guiding holes, and the outer circle of the gas-guiding bosses is connected with a plurality of gas flow channels, so that the gas-guiding bosses can connect the gas manifold port and the flow field area through the gas-guiding holes and the gas flow channels to realize the smooth introduction of the reaction gas in the flow field area. The monopolar plate of the present application is provided with a gas-guiding boss of a hollow structure, and the gas-guiding bosses together with the gas-guiding holes and the gas flow channels form a gas bridge area structure with a cavity, which can fully gather and guide the working gas to realize the inlet and outlet gas guidance of the flow field area. At the same time, the gas-guiding boss is a protruding structure, and the sealing design is more convenient and reliable, and the gas-guiding holes and the gas flow channels can be flexibly arranged, which is conducive to realizing uniform gas distribution and improving the reaction power generation effect. In addition, the monopolar plate of the present application also liberates the membrane electrode, overcomes the limitation of the membrane electrode punching on the frame, and restores the freedom of the frame design of the membrane electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0017] Figure 1A schematic diagram of the structure of the existing single cell manifold area is shown;

[0018] Figure 2 Shows Figure 1 Schematic diagram of the structure of the membrane electrode manifold region of an existing single cell;

[0019] Figure 3 Shows Figure 1 A cross-sectional view of the existing single cell manifold area at the dotted line;

[0020] Figure 4 A schematic diagram of the structure of a monopolar plate manifold region according to an embodiment of the present application is shown;

[0021] Figure 5 Shows this application Figure 4 A cross-sectional view of the bridge region structure of a single cell formed by the monopolar plate manifold region is shown;

[0022] Figure 6 Shows this application Figure 4 A perspective schematic diagram of the manifold area of ​​the unipolar plate shown;

[0023] Figure 7 Shows this application Figure 4 A three-dimensional schematic diagram of another angle of the monopolar plate manifold area is shown;

[0024] Figure 8 Shows this application Figure 4 The schematic diagram of the intake air flow cross section at A-A after the monopolar plate manifold area forms a single cell.

[0025] The above drawings include the following reference numerals:

[0026] 100, single cell; 110, membrane electrode; 111, membrane electrode manifold port; 112, punching; 120, single polar plate; 121, gas manifold port; 122, flow field area; 123, gas guide boss; 124, gas guide through hole; 125, gas flow channel; 126, point support structure; 130, sealing layer. DETAILED DESCRIPTION

[0027] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0028] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0029] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.

[0030] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein, for example. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] Figures 1 to 3 FIG. 1 shows a bridge region structure of an existing single cell 100, wherein the single cell 100 includes a membrane electrode 110 and a monopolar plate 120. Figure 2 and Figure 3As shown, on the frame of the membrane electrode 110, a punching hole 112 is provided near the membrane electrode manifold port 111. The punching hole 112 is used to serve as an inlet for the reaction gas, so as to realize the intake and exhaust of the monopolar plate 120 from the gas manifold port 121 to the flow field area 122. This has the following disadvantages: (1) Since the frame of the membrane electrode 110 needs to assume the function of the bridge area, the freedom of the frame thickness matching will be limited, affecting the design of the membrane electrode 110; (2) When the frame of the membrane electrode 110 is provided with the punching hole 112 in the bridge area, the dense holes are likely to cause stress concentration and form white edges, and delamination and other phenomena will occur after long-term operation, causing gas turbulence and affecting the intake and exhaust efficiency; (3) The frame bridge area of ​​the membrane electrode 110 is a non-rigid structure (usually the frame of the membrane electrode 110 is made of polymer materials such as PEN), which is easily affected by packaging, stack assembly, etc., causing channel deformation, thereby affecting the consistency of gas distribution of the entire stack; (4) Figure 3 At the position indicated by the dotted circle, due to the existence of the punching hole 112, it is not convenient to set the sealing layer 130 structure between the membrane electrode 110 and the monopolar plate 120, so there is a sealing risk.

[0033] Therefore, the present application proposes a novel monopolar plate 120 , which can realize the bridge area function on the monopolar plate 120 to solve the above-mentioned problem caused by the air intake through the punching holes 112 of the frame of the membrane electrode 110 in the prior art.

[0034] refer to Figures 4 to 8 As shown, the present application discloses a monopolar plate 120, which includes: a gas manifold port 121 and a flow field area 122. A circle of hollow gas-guiding bosses 123 is arranged around the gas manifold port 121, and the inner circle of the gas-guiding bosses 123 is provided with a plurality of gas-guiding through holes 124, and the outer circle of the gas-guiding bosses 123 is connected with a plurality of gas flow channels 125. The gas-guiding bosses 123 form a bridge area structure through the gas-guiding through holes 124 and the gas flow channels 125 to connect the gas manifold port 121 and the flow field area 122 (the flow channel design is not shown), so as to realize the intake and exhaust functions of the monopolar plate 120.

[0035] Through the above structural design, the monopolar plate 120 of the present application is provided with a hollow gas-guiding boss 123, and the gas-guiding boss 123 together with the gas-guiding through hole 124 and the gas flow channel 125 form a gas bridge area structure with a cavity, which can fully gather and guide the working gas to achieve the inlet and outlet gas guidance of the flow field area. At the same time, the gas-guiding boss 123 is a protruding structure, and the sealing design is more convenient and reliable, and the gas-guiding through hole 124 and the gas flow channel 125 can be flexibly arranged on the hollow gas-guiding boss 123, which is conducive to achieving uniform gas distribution and improving the reaction power generation effect.

[0036] The embodiment of the present application also overcomes the thickness restriction on the frame of the membrane electrode 110, allowing the membrane electrode 110 to be restored to a free design, facilitating the research and development, upgrading and modification of the membrane electrode 110, while also overcoming the risk of white edges and deformation of the frame of the membrane electrode 110, which is beneficial to improving the sealing stability. Figure 5 As shown, in the embodiment of the present application, a gas-conducting cavity B is formed between the hollow gas-conducting boss 123 of the monopolar plate 120 and the membrane electrode 110, and the gas-conducting cavity B can gather and guide the working gas. The gas-conducting through hole 124 is provided on the inner side of the gas-conducting boss 123, so that the gas inlet surface of the monopolar plate 120 and its contact surface with respect to the membrane electrode 110 are not coplanar, so the bridge area structure does not affect the sealing structure between the monopolar plate 120 and the membrane electrode 110. Therefore, the embodiment of the present application can be Figure 5 A sealing layer 130 is provided at the position indicated by the dotted circle to achieve reliable sealing between the monopolar plate 120 and the membrane electrode 110, thereby reducing the risk of crosstalk due to reaction gas leakage and improving the stability of the fuel cell.

[0037] In some embodiments of the present application, Figure 4 , Figure 6 and Figure 7 As shown, a plurality of air-guiding holes 124 are provided in the inner circle of the air-guiding boss 123, and the plurality of air-guiding holes 124 are evenly distributed to ensure the uniformity of the air inlet and outlet. Preferably, in the embodiment of the present application, the air-guiding holes 124 are firstly provided to fully cover the side of the air-guiding boss 123 close to the flow field area 122 to ensure the basic air inlet and outlet requirements. At the same time, the present application also extends a length at both ends of the side of the air-guiding boss 123 close to the flow field area 122 to provide more air-guiding holes 124 to further improve the air transmission capacity and cope with possible blockages.

[0038] In some embodiments of the present application, Figure 4 , Figure 6 and Figure 7 As shown, the gas flow channel 125 is arranged on the side of the gas guide boss 123 close to the flow field area 122, and there are multiple gas flow channels 125, and the outlet ends of the multiple gas flow channels 125 are connected to the flow field area 122, so that the intake and exhaust of the flow field area 122 can be smooth. In the embodiment of the present application, the monopolar plate 120 can be made of a metal plate, and the gas guide boss 123 and the gas flow channel 125 thereon can be stamped, so that the processing is simple and convenient, without the need for welding additive process, lower cost and rapid production. Figures 5 to 8As shown, the top of the gas flow channel 125 is flush with the gas guide boss 123, so it can be stamped and formed by a mold at one time, which is fast and simple to process and has low process cost. At the same time, the gas guide boss 123 and the gas flow channel 125 are designed with equal height, which also increases the pressure-resistant area, thereby reducing the risk of deformation and collapse of the gas guide boss 123 under the stacking pressure alone, and ensuring the intake and exhaust stability of the gas guide boss 123.

[0039] In some embodiments of the present application, Figures 4 to 7 As shown, the gas-guiding boss 123 is also provided with a plurality of circumferentially distributed point-shaped support structures 126, which can increase the stability of the gas-guiding boss 123, and prevent the gas-guiding boss 123 from being deformed due to extrusion during stacking and assembly, thereby affecting the gas transmission capacity of the bridge area. In addition, in some preferred embodiments of the present application, the point-shaped support structures 126 are staggered with the gas-guiding through holes 124, and do not directly block the gas-guiding through holes 124, thereby reducing the wind resistance of gas transmission, and ensuring that the gas quickly and smoothly enters the flow field area 122 for reaction and power generation.

[0040] In some embodiments of the present application, Figures 4 to 7 As shown, the point support structure 126 is a blind hole that is set on the top of the gas guide boss 123 and is recessed inward. The blind hole can be formed by stamping. In this embodiment, by setting the blind hole that is recessed inward, multi-point support can be formed when the gas guide boss 123 is squeezed, so as to stabilize the gas guide boss 123 so that it does not collapse, so as to ensure that the gas guide cavity B in the gas guide boss 123 is not squeezed, improve the stability of the gas transmission function of the bridge area, reduce the influence of external force interference on the monopolar plate 120, and improve the consistency of gas distribution.

[0041] In some embodiments of the present application, Figures 4 to 7 As shown, the point-shaped support structure 126 in the form of a blind hole is arranged at the center of the top of the gas guide boss 123 to ensure structural stability. In addition, on the side of the gas guide boss 123 close to the flow field area 122, the number of blind holes is relatively sparse compared to other sides, so as to minimize the impact on the gas transmission capacity of the gas guide boss 123 while ensuring support.

[0042] In some embodiments of the present application, a sealing ring (not shown) is also provided on the top of the air-guiding boss 123, and the sealing ring is arranged around the top of the air-guiding boss 123, which can be achieved by coating a sealant or directly using a sealing gasket. Since the air-guiding boss 123 of the present application is only provided with an open hole structure (i.e., the air-guiding through hole 124) in the inner ring, its top is flush, which can ensure that the sealing ring structure is flat and has uniform thickness, so as to achieve a stable and reliable seal, and ensure that the reaction gas chamber and the cooling water chamber are sealed and isolated. In some preferred embodiments of the present application, a portion of the sealing ring is embedded in the blind hole, so that the sealing ring can be further stabilized and the sealing performance can be improved. When the sealing ring is implemented by coating a sealant, a portion of the sealing ring can be embedded in the blind hole by overflowing the glue. When the sealing ring is implemented by a preformed sealing gasket, a positioning protrusion can be pre-set on one side of the sealing gasket to embed it in the blind hole.

[0043] In some embodiments of the present application, the monopolar plate 120 is a cathode plate or an anode plate. The gas-guiding boss 123 is arranged around the gas manifold port 121 for conveying air or hydrogen. Specifically, on the cathode plate, the gas-guiding boss 123 is arranged around the gas manifold port 121 for conveying air to achieve the intake and exhaust of the reaction air. On the anode plate, the gas-guiding boss 123 is arranged around the gas manifold port 121 for conveying hydrogen to achieve the intake and exhaust of the reaction hydrogen. It can be understood that whether the monopolar plate 120 is a cathode plate or an anode plate, the gas-guiding boss 123 thereon is arranged to protrude toward the side away from the membrane electrode 110.

[0044] The present application also discloses a single cell 100, which includes a membrane electrode 110 and a monopolar plate 120 as shown in the above embodiment. The monopolar plate 120 includes an anode plate and a cathode plate, the membrane electrode 110 is sandwiched between the anode plate and the cathode plate, and the gas guide boss 123 of the anode plate and the gas guide boss 123 of the cathode plate respectively form a gas guide cavity with the membrane electrode 110. Figure 5 As shown, the air guide cavity formed between the air guide boss 123 and the membrane electrode 110 is shown as B in the figure. Figure 8 As shown in the cross-sectional view at A-A, in the embodiment of the single cell 100 of the present application, taking the gas manifold port 121 for air intake as an example, the air intake direction of the reaction gas is shown by the dotted arrow in the figure, and the reaction gas enters the gas guide boss 123 from the gas manifold port 121 through the gas guide hole 124, and enters the flow field area 122 of the monopolar plate 120 after flowing through the gas flow channel 125, so as to carry out gas reaction to realize power generation.

[0045] The present application also discloses a fuel cell stack, which includes a plurality of stacked assembled single cells 100 as shown in the above embodiment. The fuel cell stack embodiment of the present application overcomes the limitation of the frame caused by the punching of the membrane electrode 110 by setting a gas-conducting boss 123 on the monopolar plate 120, and forming a bridge area structure with the gas-conducting boss 123, the gas-conducting through hole 124 and the gas flow channel 125, so as to restore the freedom of design of the frame of the membrane electrode 110, and also improve the reliability of the sealing structure of the fuel cell stack and the uniformity of gas distribution.

[0046] In summary, the technical solution of the present application is to set a circle of hollow gas-guiding bosses around the gas manifold port of the monopolar plate, the inner circle of the gas-guiding bosses is provided with a plurality of gas-guiding through holes, and the outer circle of the gas-guiding bosses is connected to a plurality of gas flow channels, so that the gas-guiding bosses can connect the gas manifold port and the flow field area through the gas-guiding through holes and the gas flow channels to realize the smooth introduction of the reaction gas in the flow field area. The monopolar plate of the present application is provided with a gas-guiding boss of a hollow structure, and the gas-guiding bosses together with the gas-guiding through holes and the gas flow channels form a gas bridge area structure with a cavity, which can fully gather and guide the working gas to realize the inlet and outlet gas guidance of the flow field area. At the same time, the gas-guiding boss is a protruding structure, and the sealing design is more convenient and reliable, and the gas-guiding through holes and the gas flow channels can be flexibly arranged, which is conducive to realizing uniform gas distribution and improving the reaction power generation effect. In addition, the monopolar plate of the present application also liberates the membrane electrode, overcomes the limitation of the membrane electrode punching on the frame, and restores the freedom of the frame design of the membrane electrode.

[0047] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A monopolar plate, characterized in that: The monopolar plate (120) comprises: a gas manifold port (121) and a flow field area (122); a circle of hollow gas guide bosses (123) are arranged around the gas manifold port (121); the inner circle of the gas guide bosses (123) are provided with a plurality of gas guide holes (124); the outer circle of the gas guide bosses (123) are connected with a plurality of gas flow channels (125); the gas guide bosses (123) are connected to the gas manifold port (121) and the flow field area (122) via the gas guide holes (124) and the gas flow channels (125).

2. The monopolar plate according to claim 1, characterized in that: A plurality of the air-conducting through holes (124) are provided on the inner circle of the air-conducting boss (123), and the plurality of the air-conducting through holes (124) are evenly distributed.

3. The monopolar plate according to claim 1, characterized in that: The gas flow channel (125) is arranged on a side of the gas guide boss (123) close to the flow field area (122), and a plurality of gas flow channels (125) are provided, and the outlet ends of the plurality of gas flow channels (125) are connected to the flow field area (122).

4. The monopolar plate according to any one of claims 1 to 3, characterized in that: The air guiding boss (123) is also provided with a plurality of circumferentially distributed point-shaped support structures (126), and the point-shaped support structures (126) and the air guiding through holes (124) are arranged in an alternating manner.

5. The monopolar plate according to claim 4, characterized in that: The point-shaped support structure (126) is a blind hole that is arranged on the top of the air guide boss (123) and is recessed inwardly.

6. The monopolar plate according to claim 5, characterized in that: The blind hole is arranged at a central position on the top of the air guiding boss (123), and the number of the blind holes on one side of the air guiding boss (123) close to the flow field area (122) is relatively sparse compared to other sides.

7. The monopolar plate according to claim 6, characterized in that: A sealing ring is arranged on the top of the air guide boss (123), and a part of the sealing ring is embedded in the blind hole.

8. The monopolar plate according to claim 7, characterized in that: The monopolar plate (120) is a cathode plate or an anode plate; the gas guide boss (123) is arranged around the gas manifold port (121) for conveying air or hydrogen.

9. A single battery, characterized in that: The single cell (100) comprises a membrane electrode (110), and a monopolar plate (120) as described in any one of claims 1 to 8; the monopolar plate (120) comprises an anode plate and a cathode plate, the membrane electrode (110) is sandwiched between the anode plate and the cathode plate, and the gas guide boss (123) of the anode plate and the gas guide boss (123) of the cathode plate respectively form a gas guide cavity with the membrane electrode (110).

10. A fuel cell stack, characterized in that: The fuel cell stack comprises a plurality of stacked and assembled single cells (100) as claimed in claim 9.

Images