A membrane electrode structure, a stack structure, and a fuel cell

Abstract

The application relates to the technical field of fuel cells, in particular to a membrane electrode structure of a fuel cell, a stack structure and the fuel cell. The membrane electrode structure of the fuel cell comprises a membrane electrode frame, the membrane electrode frame comprises a base part and a thickened part, the thickened part is located at two sides of the base part and is arranged in a staggered manner, and the two sides of the membrane electrode frame are provided with bipolar plates; a first sealing element and a second sealing element are oppositely arranged at the two sides of the base part, and the first sealing element and the second sealing element are located on the same straight line; the first sealing element, the second sealing element and the bipolar plates form a registration sealing structure; and a third sealing element and a fourth sealing element are arranged on the base part corresponding to the thickened part. The thickened part is added to the base part of the membrane electrode frame, so that the sealing compression design value of the third sealing element and the fourth sealing element arranged corresponding to the thickened part at the position is almost equal to the sealing compression design value at the position of the first sealing element and the second sealing element.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, specifically to a membrane electrode structure, a stack structure, and a fuel cell. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) stack consists of multiple individual cells. Each PEMFC individual cell comprises a proton exchange membrane, anode and cathode catalyst layers, a diffusion layer, bipolar plates, and cooling channels. The fuel cell stack is composed of multiple stacked individual cells. Fuel enters each individual cell through the fuel inlet distribution chamber of the fuel cell stack, flows through the internal channels, and participates in the reaction. Excess gas flows out of the fuel cell stack through the fuel outlet collection chamber. Seals are required between the reactant gases and between the reactant gases and the coolant to ensure the normal operation of the fuel cell.

[0003] The sealing of the anode and cathode gases in a fuel cell is achieved by using adhesive sealing rings with a uniform thickness. However, due to the design of the electrode plates to ensure the total thickness of the plates, the groove depth at the sealing positions is not uniform. When the stack is assembled and a certain stacking force is applied, the sealing rings are subjected to uneven force at different positions, resulting in varying compression ratios. To ensure that the airtightness meets the required specifications, some seals may have excessively high compression ratios. The initial seals may be fine, but after a period of time, the high-compression seals will have poorer resilience and will not meet the airtightness requirements. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the problem that after a period of use, the high compression sealing rebound rate of the fuel cell stack deteriorates, making it unable to meet the airtightness index requirements, thereby providing a membrane electrode structure, fuel cell stack structure and fuel cell.

[0005] To address the aforementioned technical problems, this invention provides a membrane electrode structure for a fuel cell, comprising: a membrane electrode frame, the membrane electrode frame including a base portion and a thickened portion, the thickened portion being located on both sides of the base portion and offset from each other, and bipolar plates being provided on both sides of the membrane electrode frame; a first sealing member and a second sealing member, disposed opposite to each other on both sides of the base portion, the first sealing member and the second sealing member being located on the same straight line, the first sealing member and the second sealing member, and the bipolar plates constituting an aligned sealing structure; and a third sealing member and a fourth sealing member, disposed on the base portion corresponding to the thickened portion, the third sealing member and the fourth sealing member, and the bipolar plates constituting a misaligned sealing structure.

[0006] Furthermore, the thickened portion includes a first thickened block and a second thickened block, wherein the thickness of the first thickened block is the same as the thickness of the second thickened block.

[0007] Furthermore, the thickness of the first thickened block is one-quarter of the total depth of the misaligned sealing structure.

[0008] Furthermore, the base part and the thickened part are integrally formed parts.

[0009] Furthermore, the first and third seals have the same thickness, and the second and fourth seals have the same thickness.

[0010] Furthermore, the bipolar plate is provided with a slot, and the first seal, the second seal, the third seal, and the fourth seal are disposed in the slot.

[0011] The present invention also provides a fuel cell stack structure, including the membrane electrode structure of the fuel cell.

[0012] The present invention also provides a fuel cell including the aforementioned stack structure.

[0013] The technical solution of this invention has the following advantages: 1. The membrane electrode structure for a fuel cell provided by the present invention includes: a membrane electrode frame, the membrane electrode frame including a base portion and a thickened portion, the thickened portion being located on both sides of the base portion and staggered, and bipolar plates being provided on both sides of the membrane electrode frame; a first sealing member and a second sealing member being disposed opposite to each other on both sides of the base portion, and the first sealing member and the second sealing member being located on the same straight line, the first sealing member and the second sealing member, and the bipolar plates constituting an aligned sealing structure; a third sealing member and a fourth sealing member being disposed on the base portion corresponding to the thickened portion, the third sealing member and the fourth sealing member, and the bipolar plates constituting a staggered sealing structure.

[0014] By placing the first and second seals on both sides of the base portion of the membrane electrode frame, and forming an aligned sealing structure with the two first and second seals, the membrane electrode frame, and the bipolar plate, a staggered sealing structure is achieved. A thickened portion is provided on the base portion, and the third and fourth seals are located on the base portion opposite to the thickened portion. This staggered sealing structure, consisting of the third and fourth seals, the bipolar plate, and the membrane electrode frame, effectively adds a thickened portion to the base portion of the membrane electrode frame. This ensures that the sealing compression design values ​​at the positions of the third and fourth seals corresponding to the thickened portion are almost equal to the sealing compression design values ​​at the positions of the first and second seals. This guarantees the sealing rebound rate of the first and second seals, the third seal, and the fourth seal, meeting the requirements of the airtightness index, thereby ensuring the sealing effect of the fuel cell, improving sealing safety, and ultimately extending the service life of the seals.

[0015] 2. The membrane electrode structure for a fuel cell provided by the present invention includes a first thickening block and a second thickening block, wherein the thickness of the first thickening block is the same as the thickness of the second thickening block; this arrangement facilitates the fabrication and processing of the first thickening block and the second thickening block.

[0016] 3. The membrane electrode structure for the fuel cell provided by the present invention has the same thickness for the first and third sealing elements, and the same thickness for the second and fourth sealing elements; this design facilitates the processing and manufacturing of the first, second, third, and fourth sealing elements, and saves costs.

[0017] 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

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the cathode bipolar plate of the membrane electrode structure of the fuel cell provided by the present invention; Figure 2 A front view of the anode bipolar plate of the membrane electrode structure of the fuel cell provided by the present invention; Figure 3 A schematic diagram of the membrane electrode structure of the fuel cell provided by the present invention, showing the anode bipolar plate and the cathode bipolar plate stacked together; Figure 4 A cross-sectional view of the cathode bipolar plate AA of the membrane electrode structure of the fuel cell provided by the present invention.

[0020] Explanation of reference numerals in the attached figures: 1-Membrane electrode frame; 11-Base section; 12-Thickened section; 121-First thickened block; 122-Second thickened block; 2-First sealing element; 3-Second sealing element; 4-Third sealing element; 5-Fourth sealing element; 6-Bipolar plate; 61-Slot. Detailed Implementation

[0021] In the following description, only certain exemplary embodiments are briefly described. As those skilled in the art will recognize, the described embodiments can be modified in various ways without departing from the spirit or scope of this disclosure. Therefore, the drawings and description are to be considered exemplary in nature and not restrictive.

[0022] In the description of this disclosure, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing this disclosure and 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, and therefore should not be construed as a limitation of this disclosure. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0023] In the description of this disclosure, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or connections that allow for communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this disclosure according to the specific circumstances.

[0024] In this disclosure, unless otherwise expressly 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 being 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 being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0025] The following disclosure provides numerous different embodiments or examples for implementing various structures of this disclosure. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of this disclosure. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in this disclosure, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0026] The preferred embodiments of this disclosure are described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0027] Please see Figures 1 to 4 As shown, the present invention provides a membrane electrode structure for a fuel cell, comprising: a membrane electrode frame 1, the membrane electrode frame 1 including a base portion 11 and a thickened portion 12, the thickened portion 12 being located on both sides of the base portion 11 and staggered, and bipolar plates 6 being provided on both sides of the membrane electrode frame 1; a first sealing member 2 and a second sealing member 3 being disposed opposite to each other on both sides of the base portion 11, and the first sealing member 2 and the second sealing member 3 being located on the same straight line, the first sealing member 2 and the second sealing member 3, and the bipolar plates 6 forming an aligned sealing structure; a third sealing member 4 and a fourth sealing member 5 being disposed on the base portion 11 corresponding to the thickened portion 12, the third sealing member 4 and the fourth sealing member 5, and the bipolar plates 6 forming a staggered sealing structure.

[0028] By setting the first seal 2 and the second seal 3 on both sides of the base portion 11 of the membrane electrode frame 1, and forming an aligned sealing structure with the two first seals 2 and the second seal 3, the membrane electrode frame 1, and the bipolar plate 6, a staggered sealing structure is formed. A thickened portion 12 is provided on the base portion 11, and the third seal 4 and the fourth seal 5 are provided on the base portion 11 opposite to the thickened portion 12. This staggered sealing structure, composed of the third seal 4 and the fourth seal 5, the bipolar plate 6, and the membrane electrode frame 1, effectively adds a thickened portion 12 to the base portion 11 of the membrane electrode frame 1. This ensures that the sealing compression design value at the positions of the third seal 4 and the fourth seal 5 corresponding to the thickened portion 12 is almost equal to the sealing compression design value at the positions of the first seals 2 and the second seal 3. This guarantees the sealing rebound rate of the first seals 2 and the second seal 3, the third seal 4, and the fourth seal 5, meeting the requirements of the airtightness index, thereby ensuring the sealing effect of the fuel cell, improving sealing safety, and ultimately increasing the service life of the seals.

[0029] In this embodiment, the base portion 11 and the thickened portion 12 of the membrane electrode frame 1 are integrally formed. This facilitates the fabrication and processing of the membrane electrode frame 1, and also improves the overall strength and rigidity of the membrane electrode.

[0030] The bipolar plate 6 has two plates: the one located above the membrane electrode frame 1 is the anode plate, and the one located below the membrane electrode frame 1 is the cathode plate.

[0031] The membrane electrode frame 1, bipolar plate 6, first seal 2, and second seal 3 form an aligned sealing structure; the membrane electrode frame 1, bipolar plate 6, third seal 4, and fourth seal 5 form a staggered sealing structure that is continuously arranged. In this embodiment, only a part of it is listed separately.

[0032] In some optional embodiments, the thickened portion 12 includes a first thickened block 121 and a second thickened block 122. The thickness of the first thickened block 121 is the same as the thickness of the second thickened block 122. Specifically, the thickness can be set according to the actual thickness of the first seal 2, the second seal 3, the third seal 4, and the fourth seal 5. It also needs to be set with reference to the depth of the slot 61 on the bipolar plate 6.

[0033] In some optional embodiments, the thickness of the first thickening block 121 is one-quarter of the total depth of the misaligned sealing structure. The total depth of the misaligned sealing structure is the thickness between one bipolar plate 6 and the other bipolar plate 6, specifically including the total thickness of the third seal 4, the base portion 11 of the membrane electrode frame 1, and the thickening portion 12.

[0034] The thickness of the second thickening block 122 can be one-quarter of the total depth of the misaligned sealing structure. Specifically, it can be set according to the actual situation.

[0035] For ease of explanation, the sealing of the cooling paths on both sides of the membrane electrode frame 1 is taken as an example; the sealing of the air side and hydrogen side is similar. The thicknesses of the first sealing element 2, the second sealing element 3, the third sealing element 4, and the fourth sealing element 5 are now defined. Let the thickness of the first sealing element 2 be h1 and the thickness of the second sealing element 3 be h2. Specifically, the thicknesses of the first sealing element 2 and the third sealing element 4 are the same, i.e., both are h1, and the thicknesses of the second sealing element 3 and the fourth sealing element 5 are the same, i.e., both are h2. This design facilitates the processing and manufacturing of the first sealing element 2, the second sealing element 3, the third sealing element 4, and the fourth sealing element 5, thus saving costs.

[0036] The total depth of the misaligned sealing structure of the third seal 4 is set to h3, and the total depth of the misaligned sealing structure of the fourth seal 5 is set to h4. The thickness of the first thickening block 121 is equal to the thickness of h3-h1, and the thickness of the base part 11 also needs to be considered. The thickness of the second thickening block 122 is equal to the thickness of h4-h2, and the thickness of the base part 11 also needs to be considered.

[0037] The present invention also provides a fuel cell stack structure, including the membrane electrode structure of the fuel cell.

[0038] The present invention also provides a fuel cell including the aforementioned stack structure.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A membrane electrode structure for a fuel cell, characterized in that, include: The membrane electrode frame (1) includes a base part (11) and a thickened part (12). The thickened part (12) is located on both sides of the base part (11) and is staggered. Bipolar plates (6) are provided on both sides of the membrane electrode frame (1). The first seal (2) and the second seal (3) are disposed opposite to each other on both sides of the base part (11), and the first seal (2) and the second seal (3) are located on the same straight line. The first seal (2), the second seal (3), and the bipolar plate (6) constitute an alignment sealing structure. The third seal (4) and the fourth seal (5) are provided on the base part (11) corresponding to the thickened part (12), and the third seal (4) and the fourth seal (5), together with the bipolar plate (6), constitute a misaligned sealing structure.

2. The membrane electrode structure of the fuel cell according to claim 1, characterized in that, The thickened portion (12) includes a first thickened block (121) and a second thickened block (122), wherein the thickness of the first thickened block (121) is the same as the thickness of the second thickened block (122).

3. The membrane electrode structure of the fuel cell according to claim 2, characterized in that, The thickness of the first thickening block (121) is one-quarter of the total depth of the misaligned sealing structure.

4. The membrane electrode structure of the fuel cell according to claim 3, characterized in that, The base part (11) and the thickened part (12) are integrally formed parts.

5. The membrane electrode structure of the fuel cell according to claim 4, characterized in that, The first seal (2) and the third seal (4) have the same thickness, and the second seal (3) and the fourth seal (5) have the same thickness.

6. The membrane electrode structure of the fuel cell according to claim 4 or 5, characterized in that, The bipolar plate (6) is provided with a slot (61), and the first seal (2), the second seal (3), the third seal (4), and the fourth seal (5) are provided in the slot (61).

7. A fuel cell stack structure, characterized in that, The membrane electrode structure of the fuel cell included in any one of claims 1-6.

8. A fuel cell, characterized in that, Includes the fuel cell stack structure as described in claim 7.

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