A bipolar plate positive and negative pole gas sealing structure, bipolar plate and fuel cell

Abstract

The present application relates to the technical field of fuel cell, in particular to a bipolar plate anode and cathode gas sealing structure, bipolar plate and fuel cell; the bipolar plate anode and cathode gas sealing structure includes: a body, the body is provided with a plurality of hollow structures at both ends, the body has a first surface; third protruding structure, the third protruding structure is arranged along the outer edge of the body; the distance between the first surface and the top plane of the first protruding structure or third protruding structure is h1, the distance between the first surface and the top plane of the second protruding structure is h2, and h1>h2.The bipolar plate anode and cathode gas sealing structure can effectively balance the pressure on the sealing rubber ring and the membrane electrode, greatly improve the consistency of the stack and stress, avoid the local indentation problem of the membrane electrode gas diffusion layer, ensure the air tightness of the stack under multiple working conditions, greatly improve the operation efficiency of the fuel cell, and then ensure the stable operation of the stack.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, specifically to a bipolar plate anode and cathode gas sealing structure, a bipolar plate, and a fuel cell. Background Technology

[0002] A fuel cell stack is a device that directly generates electricity from fuel through an electrochemical reaction; it is also known as an electrochemical generator. It boasts advantages such as high power density, high conversion rate, and low environmental pollution. Bipolar plates are key components of a fuel cell, primarily functioning to separate reactant gases, facilitate the flow of reactant gases and coolant, collect and transmit current, and support the membrane electrode assembly (MEA). In practical applications, multiple bipolar plates and MEAs are typically stacked to form a fuel cell stack, which is composed of multiple individual cells connected in series. The quality of the seal between the MEA and bipolar plates significantly impacts the formation and safety of the fuel cell stack.

[0003] The existing bipolar plate sealing structure has poor sealing performance and cannot balance the force distribution between the sealing ring and the membrane electrode, which leads to local indentation problems in the gas diffusion layer of the membrane electrode. In severe cases, it can even cause the membrane electrode to break, seriously affecting the reliability of the fuel cell stack. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the poor sealing performance of the existing bipolar plate sealing structure, which cannot balance the force distribution between the sealing ring and the membrane electrode, resulting in local indentation problems in the gas diffusion layer of the membrane electrode, and in severe cases, it can even lead to membrane electrode damage, which seriously affects the reliability of the fuel cell stack. The present invention provides a bipolar plate anode and cathode gas sealing structure, a bipolar plate, and a fuel cell.

[0005] To solve the above technical problems, the present invention provides a bipolar plate anode and cathode gas sealing structure, comprising: a body having multiple hollow structures at both ends, the body having a first surface; a first protrusion structure disposed along the edge of the hollow structure; a second protrusion structure disposed close to the first protrusion structure, at least partially enclosing the first protrusion structure, and having a first sealing groove between the first protrusion structure and the second protrusion structure; a third protrusion structure disposed along the outer edge of the body, and having a second sealing groove between the third protrusion structure and the second protrusion structure; the distance between the first surface and the top plane of the first or third protrusion structure is h1, the distance between the first surface and the top plane of the second protrusion structure is h2, wherein h1 > h2.

[0006] Furthermore, the distance between h1 and h2 is 0.01~0.2mm.

[0007] Furthermore, the width of the second sealing groove is equal to the width of the first sealing groove.

[0008] Furthermore, the second protruding structure includes: a wrapping segment, which is U-shaped and used to wrap multiple hollow structures; and a connecting segment, which is connected to the wrapping segment and is located between two adjacent hollow structures, and is smoothly connected to the wrapping segment.

[0009] Furthermore, it also includes positioning blocks, of which there are two, and the positioning blocks are located within the package segment.

[0010] Furthermore, it also includes a reinforcing rib structure, which is disposed on the first protrusion structure, the second protrusion structure, and the third protrusion structure.

[0011] Furthermore, the body is manufactured using a stamping method.

[0012] The present invention also provides a bipolar plate, including the bipolar plate anode and cathode gas sealing structure described in the present invention.

[0013] The present invention also provides a fuel cell including the bipolar plate described herein.

[0014] The technical solution of this invention has the following advantages:

[0015] 1. The bipolar plate anode and cathode gas sealing structure provided by the present invention includes: a body, wherein multiple hollow structures are provided at both ends of the body, and the body has a first surface; a first protrusion structure is provided along the edge of the hollow structure; a second protrusion structure is provided close to the first protrusion structure, at least partially covering the first protrusion structure, and a first sealing groove is provided between the first protrusion structure and the second protrusion structure; a third protrusion structure is provided along the outer edge of the body, and a second sealing groove is provided between the third protrusion structure and the second protrusion structure; the distance between the first surface and the top plane of the first protrusion structure or the third protrusion structure is h1, the distance between the first surface and the top plane of the second protrusion structure is h2, and h1 > h2.

[0016] When in use, this bipolar plate features a first sealing groove and a second sealing groove, with sealing rings installed within both grooves. Furthermore, since the distance between the first surface and the top plane of the first or third protruding structure is h1, and the distance between the first surface and the top plane of the second protruding structure is h2 (where h1 > h2), the first, second, and third protruding structures form a structure that is high at both ends and low in the middle. This design ensures the airtightness of the fuel cell stack under various operating conditions, while also balancing the pressure on the sealing rings and the membrane electrode assembly. This significantly improves the consistency of the fuel cell stack assembly and stress distribution, preventing localized indentations in the membrane electrode gas diffusion layer and greatly enhancing the fuel cell's operating efficiency, thereby ensuring stable stack operation.

[0017] 2. The bipolar plate anode and cathode gas sealing structure provided by the present invention has a second sealing structure with a width equal to that of the first sealing structure, thereby avoiding errors when installing sealing rings in the first and second sealing grooves; at the same time, it also facilitates the processing of the first and second sealing grooves, effectively reducing processing costs.

[0018] 3. The bipolar plate anode-cathode gas sealing structure provided by the present invention further includes a reinforcing rib structure, which is disposed on the first protrusion structure, the second protrusion structure, and the third protrusion structure. The reinforcing rib structure is provided to ensure stress dispersion of the body during the production stamping process, thereby preventing damage to the flatness of the body. It can effectively alleviate the problems of uneven sealing of the internal bipolar plate and MEA and uneven pressure distribution under high-power stacking, and effectively improve the overall consistency of the stack.

[0019] The summary section is provided to present the chosen concepts in a simplified form, which will be further described in the detailed description below. The summary section is not intended to identify essential or necessary features of this disclosure, nor is it intended to limit the scope of this disclosure. Attached Figure Description

[0020] The above and other objects, features and advantages of this disclosure will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0021] Figure 1 A schematic diagram of the structure of the fuel cell bipolar plate provided by the present invention is shown;

[0022] Figure 2A schematic diagram of the structure of the first sealing groove provided by the present invention is shown;

[0023] Figure 3 Cross-sectional views of the first protrusion structure, the second protrusion structure, and the third protrusion structure provided by the present invention are shown.

[0024] 1-Body; 11-First surface; 12-Hollow structure; 13-First protruding structure; 14-Second protruding structure; 15-Third protruding structure; 16-First sealing groove; 17-Second sealing groove; 171-Wrapping section; 172-Connecting section;

[0025] 2-Location block;

[0026] 3-Reaction zone;

[0027] 4- Hydrogen inlet;

[0028] 5- Hydrogen outlet;

[0029] 6-Air outlet;

[0030] 7-Air inlet;

[0031] 8-Liquid water output;

[0032] 9-Liquid water inlet. Detailed Implementation

[0033] Embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure will be thorough and complete, and will fully convey the scope of the present disclosure to those skilled in the art.

[0034] The term "comprising" and its variations as used herein signify open inclusion, i.e., "including but not limited to". Unless otherwise stated, the term "or" means "and / or". The term "based on" means "at least partially based on". The terms "one example embodiment" and "one embodiment" mean "at least one example embodiment". The term "another embodiment" means "at least one additional embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0035] Please see Figures 1 to 3 As shown, this embodiment of the invention provides a bipolar plate anode-cathode gas sealing structure, which is part of the bipolar plate. The fuel cell stack is composed of several bipolar plates and membrane electrode assemblies stacked together. The bipolar plate includes six fluid openings, which are located near the four corners of the bipolar plate for fluid to flow in or out.

[0036] The bipolar plate anode and cathode gas sealing structure includes: a body 1, with multiple hollow structures 12 at both ends of the body 1, and the body 1 having a first surface 11; a first protruding structure 13, disposed along the edge of the hollow structure 12; a second protruding structure 14, disposed close to the first protruding structure 13, at least partially enclosing the first protruding structure 13, and having a first sealing groove 16 between the first protruding structure 13 and the second protruding structure 14; a third protruding structure 15, disposed along the outer edge of the body 1, and having a second sealing groove 17 between the third protruding structure 15 and the second protruding structure 14; the distance between the first surface 11 and the top plane of the first protruding structure 13 or the third protruding structure 15 is h1, and the distance between the first surface 11 and the top plane of the second protruding structure 14 is h2, wherein h1 > h2.

[0037] When in use, this bipolar plate is equipped with a first sealing groove 16 and a second sealing groove 17, and sealing rings are installed in the first sealing groove 16 and the second sealing groove 17. Simultaneously, since the distance between the first surface 11 and the top plane of the first protruding structure 13 or the third protruding structure 15 is h1, and the distance between the first surface 11 and the top plane of the second protruding structure 14 is h2, where h1 > h2, meaning the distances between the first surface 11 and the top planes of the first protruding structure 13 and the third protruding structure 15 are equal (h1), and the distance between the first surface 11 and the top plane of the second protruding structure 14 is h2, and h1 > h2, the first protruding structure 13, the second protruding structure 14, and the third protruding structure 15 have a structure that is high at both ends and low in the middle. This structure ensures the airtightness of the fuel cell stack under various operating conditions, while also balancing the pressure on the sealing rings and the membrane electrode assembly. This greatly improves the consistency of the fuel cell stack assembly and stress, avoids local indentation problems in the gas diffusion layer of the membrane electrode assembly, significantly improves the operating efficiency of the fuel cell, and thus ensures the stable operation of the fuel cell stack.

[0038] In some optional embodiments, the distance between h1 and h2 is 0.01~0.2mm. Specifically, the distance between h1 and h2 is 0.02mm, 0.05mm, 0.1mm, etc., and can be set according to the actual situation.

[0039] The body 1 has a reaction zone 3 in the middle, which contains a gas flow channel. Along the width of one end of the body 1, there are sequentially arranged hydrogen inlet 4, liquid water outlet 8, and air outlet 6; along the width of the other end of the body 1, there are sequentially arranged air inlet 7, liquid water inlet 9, and hydrogen outlet 5. Hydrogen inlet 4 and hydrogen outlet 5 are arranged diagonally along the body 1, as are air inlet 7 and air outlet 6. Liquid water outlet 8 and liquid water inlet 9 are symmetrically arranged along the length of the body 1. The hydrogen inlet 4, liquid water outlet 8, air outlet 6, air inlet 7, liquid water inlet 9, and hydrogen outlet 5 form a hollow structure 12.

[0040] In some optional embodiments, the width of the second sealing groove 17 is equal to the width of the first sealing groove 16, thereby avoiding errors when installing the sealing ring in the first sealing groove 16 and the second sealing groove 17; at the same time, it also facilitates the processing of the first sealing groove 16 and the second sealing groove 17, which can effectively reduce processing costs.

[0041] In some optional embodiments, the second sealing groove 17 includes a wrapping section 171 and a connecting section 172; wherein, the wrapping section 171 is U-shaped and is used to wrap the plurality of the hollow structures 12. That is, the wrapping section 171 at one end of the body 1 is used to wrap the hydrogen inlet 4, the liquid water outlet 8, and the air outlet 6; the wrapping section 171 at the other end of the body 1 is used to wrap the air inlet 7, the liquid water inlet 9, and the hydrogen outlet 5.

[0042] The connecting segment 172 is connected to the wrapping segment 171, and the connecting segment 172 is located between two adjacent hollow structures 12. One end of the main body 1 has three hollow structures 12: a hydrogen inlet 4, a liquid water outlet 8, and an air outlet 6. The first connecting segment 172 is located between the hydrogen inlet 4 and the liquid water outlet 8, and the second connecting segment 172 is located between the liquid water outlet 8 and the air outlet 6. The other end of the main body 1 also has three hollow structures 12: an air inlet 7, a liquid water inlet 9, and a hydrogen outlet 5. The third connecting segment 172 is located between the air inlet 7 and the liquid water inlet 9, and the fourth connecting segment 172 is located between the liquid water inlet 9 and the hydrogen outlet 5.

[0043] The connecting segment 172 is smoothly connected to the wrapping segment 171, which facilitates the connection between the connecting segment 172 and the wrapping segment 171 and avoids gaps that could lead to the leakage of gas or liquid.

[0044] In some optional embodiments, the body 1 is made by stamping, wherein the first sealing groove 16 and the second sealing groove 17 are both made by stamping. This method of making the body 1 results in high production efficiency, convenient operation, and easy mechanization and automation.

[0045] In some optional embodiments, the bipolar plate anode and cathode gas sealing structure further includes positioning blocks 2, of which there are two, and the positioning blocks 2 are disposed within the wrapping section 171; the positioning blocks 2 are provided to facilitate positioning during the fabrication of the body 1, and also to facilitate the installation of sealing rings in the first sealing groove 16 and the second sealing groove 17.

[0046] In some optional embodiments, the bipolar plate anode-cathode gas sealing structure further includes reinforcing ribs, which are disposed on the first protrusion 13, the second protrusion 14, and the third protrusion 15. The reinforcing ribs ensure stress dispersion during the stamping process of the main body 1, preventing damage to its flatness. This effectively alleviates the sealing problems of the internal bipolar plates and MEA, as well as uneven pressure distribution, under high-power stack conditions, thus significantly improving the overall consistency of the stack.

[0047] Specifically, the reinforcing rib structure can be a reinforcing plate disposed on the first protrusion structure 13, the second protrusion structure 14, and the third protrusion structure 15.

[0048] The present invention also provides a bipolar plate, including the aforementioned bipolar plate anode and cathode gas sealing structure.

[0049] The present invention also provides a fuel cell including the aforementioned bipolar plate.

[0050] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, and are not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical applications, or technical improvements to the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A bipolar plate anode and cathode gas seal structure, characterized by, The application relates to a bipolar plate gas sealing structure. The body (1) is provided with a plurality of hollow structures (12) at two ends, and has a first surface (11); A first convex structure (13) is arranged along the edge of the hollow structure (12); A second convex structure (14) is arranged close to the first convex structure (13) and at least partially wraps the first convex structure (13), and a first sealing groove (16) is arranged between the first convex structure (13) and the second convex structure (14); A third convex structure (15) is arranged along the outer edge of the body (1), and a second sealing groove (17) is arranged between the third convex structure (15) and the second convex structure (14); The distance between the first surface (11) and the top plane of the first convex structure (13) or the third convex structure (15) is h1, and the distance between the first surface (11) and the top plane of the second convex structure (14) is h2, and h1>h2; The second convex structure (14) comprises: A wrapping section (171) in a U shape, which is used for wrapping a plurality of hollow structures (12); A connecting section (172) connected with the wrapping section (171), which is located between two adjacent hollow structures (12) and is smoothly connected with the wrapping section (171); Two positioning blocks (2) are arranged in the wrapping section (171); One end of the body (1) is provided with three hollow structures (12), and the other end of the body (1) is also provided with three hollow structures (12).

2. The bipolar plate anode-cathode gas seal structure according to claim 1, characterized by, The distance between h1 and h2 is 0.01-0.2 mm.

3. The bipolar plate anode and cathode gas seal structure of claim 2, wherein, The width of the second sealing groove (16) is equal to the width of the first sealing groove (17).

4. The bipolar plate anode and cathode gas seal structure of claim 1, wherein, A reinforcing rib structure is arranged on the first convex structure (13), the second convex structure (14) and the third convex structure (15).

5. The bipolar plate anode and cathode gas seal structure according to claim 1 or 4, characterized in that, The body (1) is made by stamping.

6. A bipolar plate, characterized by The bipolar plate anode and cathode gas sealing structure of any one of claims 1-5 is also included.

7. A fuel cell characterized by comprising: The bipolar plate of claim 6 is also included.

Images