Air-cooled fuel cell stack structure

Abstract

This utility model discloses an air-cooled fuel cell stack structure, relating to the field of proton exchange membrane fuel cell technology. It includes stacked single-cell units, each of which comprises a first bipolar plate, a second bipolar plate, a third bipolar plate, and a single-cell membrane electrode assembly. The first bipolar plate has a base plate, side plates, and ear plates, which surround and form a first receiving cavity and a second receiving cavity. The second bipolar plate is placed on the base plate and located within the first receiving cavity, and the third bipolar plate is placed on the second bipolar plate and located within the second receiving cavity. In this utility model, the first bipolar plate, through the combination of the base plate, side plates, and inwardly extending ear plates, forms the first and second receiving cavities. This constrains the second and third bipolar plates within predefined cavities, enhancing the overall vibration and shock resistance of the stack. It effectively prevents relative displacement of components due to vibration during dynamic applications, thereby reducing contact resistance and improving the stack's conductivity stability and operational reliability.

Description

Technical Field

[0001] This utility model relates to the field of proton exchange membrane fuel cell technology, and in particular to an air-cooled fuel cell stack structure. Background Technology

[0002] With the sharp decline in traditional fossil fuel reserves and increasing environmental pressure, the development of low-carbon renewable energy has become a global focus. Hydrogen energy, as a core carrier for deep decarbonization, has seen its energy conversion technology—proton exchange membrane fuel cells (PEMFCs)—become a key research area due to its high efficiency (conversion efficiency ≥60%), zero emissions (producing only water), and lack of Carnot cycle limitations. Current research on PEMFCs mainly focuses on catalysts, slurry formulations, membrane electrode assemblies, bipolar plate channels, and stack structures.

[0003] In terms of stack structure, the air-cooled proton exchange membrane fuel cell stack consists of multiple single cells connected in series. It also includes seven parts: end plates, bipolar plates, current collectors, insulating plates, membrane electrode assemblies (MEAs), fasteners, and seals. Stack assembly begins with the pre-installation of the lower end plates and lower current collectors. Using positioning rods, the bipolar plates, MEAs, and bipolar plates are stacked sequentially on the lower current collector, assembling the first single cell. This stacking process is repeated until the designed number of single cells is reached. Then, the upper current collector and upper end plates are installed on top, completing the initial stack assembly. Next, using hydraulic presses or other pressure devices, the components are compressed to create a seal. Finally, bolts or pressure bands are used to tighten the seal, completing the entire stack assembly.

[0004] However, traditional fuel cell stacks use a rectangular bipolar plate stacked packaging. When applied to products such as electric bicycles, drones, forklifts, and ships, they are susceptible to vibration in dynamic applications, leading to component displacement, increased contact resistance, and shortened lifespan.

[0005] In summary, current bipolar plate structure designs lack innovation, with the mainstream still being a single cuboid. There is an urgent need for a highly stable fuel cell stack structure. Utility Model Content

[0006] The purpose of this invention is to provide an air-cooled fuel cell stack structure to solve the problems existing in the prior art and improve the stability of the stack structure.

[0007] To achieve the above objectives, this utility model provides the following solution:

[0008] An air-cooled fuel cell stack structure includes stacked single cell units, each single cell unit comprising:

[0009] The first bipolar plate has a base plate, two side plates perpendicular to the base plate, and ear plates respectively disposed at the ends of the side plates; the two ear plates are parallel to the base plate and extend inward;

[0010] The first receiving cavity is formed by the line connecting the lower surfaces of the two ear plates, the upper surface of the bottom plate, and the inner surfaces of the two side plates;

[0011] The second receiving cavity is formed by the line connecting the upper and lower surfaces of the two ear plates and the inner side surface of the ear plates;

[0012] The second bipolar plate is placed on the base plate and located in the first receiving cavity, and is in contact with the side plate and the ear plate;

[0013] The third bipolar plate is placed on the second bipolar plate and located in the second receiving cavity, and is in contact with the two ear plates;

[0014] A single-cell membrane electrode is sandwiched between the base plate and the second bipolar plate, and between the second bipolar plate and the third bipolar plate.

[0015] In one exemplary embodiment, a first limiting structure is further provided at the point where the second bipolar plate and the ear plate fit together, for limiting the relative displacement between the two in the ear plate extension direction.

[0016] In an exemplary embodiment, the first limiting structure includes a first limiting hole formed at the fitting area and a first limiting rod inserted therein, wherein the extending direction of the first limiting hole forms an angle with the extending direction of the ear plate.

[0017] In an exemplary embodiment, the first limiting hole is formed by the mating of a first arc-shaped groove on the lower surface of the ear plate and a corresponding second arc-shaped groove on the upper surface of the second bipolar plate.

[0018] In one exemplary embodiment, a second limiting structure is also provided at the contact point of adjacent single battery cells to limit their relative displacement in the extension direction of the ear plate.

[0019] In an exemplary embodiment, the second limiting structure includes a second limiting hole formed at the fitting area and a second limiting rod inserted therein, wherein the extending direction of the second limiting hole forms an angle with the extending direction of the ear plate.

[0020] In an exemplary embodiment, the second limiting hole is formed by the mating of a third arc-shaped groove on the upper surface of the ear plate and a corresponding fourth arc-shaped groove on the lower surface of the base plate.

[0021] In one exemplary embodiment, a third limiting structure is also provided on the side plate for limiting the relative displacement of adjacent single battery cells in a direction parallel to the base plate.

[0022] In an exemplary embodiment, the third limiting structure includes a third limiting hole and a third limiting rod inserted therein, wherein the extending direction of the third limiting hole is perpendicular to the base plate.

[0023] In an exemplary embodiment, the surfaces of the first bipolar plate, the second bipolar plate, and the third bipolar plate are all engraved with anode and cathode channels, and each is provided with a channel inlet and a channel outlet communicating with the anode and cathode channels. The channel inlets and channel outlets provided on the three are aligned with each other.

[0024] The present invention achieves the following technical advantages over the prior art:

[0025] The unique combination of the base plate, side plate, and inwardly extending ear plate structure of the first bipolar plate forms a nested first and second receiving cavity, which precisely constrains and fits the second and third bipolar plates within the predefined cavity space. This mechanical structure significantly enhances the overall vibration and shock resistance of the fuel cell stack, effectively preventing relative displacement of components caused by vibration in dynamic applications such as electric bicycles and drones. This reduces contact resistance, improves the conductivity stability and operational reliability of the fuel cell stack, and ultimately extends the service life of the fuel cell stack. At the same time, this self-positioning structure also simplifies the assembly precision requirements. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the structure of an air-cooled fuel cell stack disclosed in a specific embodiment of the present invention.

[0028] Figure 2 for Figure 1 The main view;

[0029] Figure 3 for Figure 2 Top view;

[0030] Figure 4 for Figure 2 A bottom view;

[0031] Figure 5 for Figure 1 Exploded view of a single cell in the middle;

[0032] Figure 6 for Figure 5 A schematic diagram of the structure of the first bipolar plate in the middle;

[0033] Figure 7 for Figure 6 The main view;

[0034] Figure 8 for Figure 7 Top view;

[0035] Figure 9 for Figure 7 A bottom view;

[0036] Figure 10 for Figure 5 A schematic diagram of the structure of the second bipolar plate in the middle;

[0037] Figure 11 for Figure 10 The main view;

[0038] Figure 12 for Figure 11 Top view;

[0039] Figure 13 for Figure 11 A bottom view;

[0040] Figure 14 for Figure 5 A schematic diagram of the structure of the third bipolar plate;

[0041] Figure 15 for Figure 14 The main view;

[0042] Figure 16 for Figure 15 Top view;

[0043] Figure 17 for Figure 15 A bottom view;

[0044] in:

[0045] 1. Single battery cell;

[0046] 2. First bipolar plate; 21. Base plate; 22. Side plate; 23. Ear plate; 24. First receiving cavity; 25. Second receiving cavity;

[0047] 3. Second bipolar plate;

[0048] 4. Third bipolar plate;

[0049] 5. Single-cell membrane electrode;

[0050] 61. First limiting hole; 611. First arc-shaped groove; 612. Second arc-shaped groove; 62. First limiting rod;

[0051] 71. Second limiting hole; 711. Third arc-shaped groove; 712. Fourth arc-shaped groove; 72. Second limiting rod;

[0052] 81. Third limiting hole; 82. Third limiting rod;

[0053] 9. Yin and Yang channels; 91. Channel inlet; 92. Channel outlet. Detailed Implementation

[0054] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Those skilled in the art can easily understand other advantages and effects of the present utility model from the content disclosed in this specification. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0055] The purpose of this invention is to provide an air-cooled fuel cell stack structure to solve the problems existing in the prior art and improve the stability of the stack structure.

[0056] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0057] Please refer to Figures 1 to 17 This embodiment provides an air-cooled fuel cell stack structure, including stacked single cell units 1. Each single cell unit 1 includes a first bipolar plate 2, a second bipolar plate 3, a third bipolar plate 4, and a single cell membrane electrode 5, wherein:

[0058] The first bipolar plate 2 has a base plate 21, two side plates 22 perpendicular to the base plate 21, and ear plates 23 respectively disposed at the ends of the side plates 22. The two ear plates 23 are parallel to the base plate 21 and extend inward, that is, extend in the direction that the two ear plates 23 are close to each other.

[0059] The structure of the first bipolar plate 2 can form two receiving cavities, namely the first receiving cavity 24 and the second receiving cavity 25. The first receiving cavity 24 is formed by the line connecting the lower surfaces of the two ear plates 23, the upper surface of the bottom plate 21 and the inner surfaces of the two side plates 22; the second receiving cavity 25 is formed by the line connecting the upper surfaces and lower surfaces of the two ear plates 23 and the inner surfaces of the ear plates 23.

[0060] The second bipolar plate 3 is placed on the base plate 21 and located in the first receiving cavity 24, and is in contact with the side plate 22 and the ear plate 23; the third bipolar plate 4 is placed on the second bipolar plate 3 and located in the second receiving cavity 25, and is in contact with the two ear plates 23.

[0061] The single-cell membrane electrode 5 is sandwiched between the base plate 21 and the second bipolar plate 3, and between the second bipolar plate 3 and the third bipolar plate 4.

[0062] The first bipolar plate 2, consisting of a base plate 21, a side plate 22, and an ear plate 23 extending inward, forms a left-handed 90° "C"-shaped structure, creating a nested first receiving cavity 24 and a second receiving cavity 25. This allows the second bipolar plate 3 and the third bipolar plate 4 to be precisely constrained and fitted within a predefined cavity space. This mechanical interlocking structure significantly enhances the overall vibration and shock resistance of the fuel cell stack, effectively preventing relative displacement of components due to vibration in dynamic applications such as electric bicycles and drones. This reduces contact resistance, improves the conductivity stability and operational reliability of the fuel cell stack, and ultimately extends the service life of the fuel cell stack. At the same time, this self-positioning structure simplifies the assembly precision requirements.

[0063] The second bipolar plate 3 is constrained within the first receiving cavity 24, fitting against the side plate 22 and the ear plate 23; the third bipolar plate 4 is constrained within the second receiving cavity 25, fitting against the two ear plates 23. This nested constraint relationship, especially the covering and limiting effect of the ear plates 23 on the upper bipolar plate, physically restricts the free movement space of each component in the lateral and vertical directions, forming a mechanical interlocking effect similar to "mortise and tenon" or "drawer". This greatly enhances the fuel cell stack's ability to resist external vibration and impact, fundamentally solving the key problem of easy loosening and displacement in traditional flat-plate stacked fuel cell stacks during dynamic applications.

[0064] The reduction in relative displacement between components ensures the stability of the contact interfaces between bipolar plates, between bipolar plates and membrane electrodes, and between bipolar plates and current collectors / endplates. Stable contact means lower contact resistance and more uniform current distribution, improving the energy conversion efficiency and output stability of the fuel cell stack.

[0065] Vibration-induced component fretting wear is one of the important causes of fuel cell stack performance degradation and failure. This embodiment effectively suppresses fretting, reduces the resulting material wear, seal failure and performance degradation risks, thereby significantly extending the overall service life of the fuel cell stack.

[0066] The reduction in component displacement also means a reduction in the shear stress on the seal, which helps maintain the integrity of the sealing interface, reduces the risk of reactive gas leakage, and improves operational safety.

[0067] The structure of the cavity provides a clear positioning reference for the second and third bipolar plates, reducing the alignment difficulty and accuracy requirements during assembly, which is conducive to improving production efficiency and product consistency.

[0068] In summary, this embodiment effectively solves the structural stability problem of traditional planar stacked fuel cell stacks in dynamic environments through an innovative three-dimensional nested structure, providing a key structural foundation for developing high-performance, long-life proton exchange membrane fuel cell systems suitable for mobile platforms.

[0069] To further limit the relative displacement between components and enhance stability, this embodiment also includes a first limiting structure, a second limiting structure, and a third limiting structure.

[0070] The first limiting structure is disposed at the contact point between the second bipolar plate 3 and the ear plate 23, including a first limiting hole 61 formed at the contact point and a first limiting rod 62 inserted therein. The extending direction of the first limiting hole 61 forms an angle with the extending direction of the two ear plates 23 approaching each other, preferably 90°, to limit the two in the extending direction of the ear plates 23, i.e. Figure 2 The relative displacement in the left and right directions. The first limiting hole 61 is specifically composed of a first arc-shaped groove 611 formed on the lower surface of the ear plate 23 and a corresponding second arc-shaped groove 612 formed on the upper surface of the second bipolar plate 3.

[0071] The second limiting structure is disposed at the contact point of adjacent single battery cells 1, including a second limiting hole 71 opened at the contact point and a second limiting rod 72 inserted therein. The extending direction of the second limiting hole 71 forms an angle with the extending direction of the two ear plates 23 approaching each other, preferably 90°, to limit the two in the extending direction of the ear plates 23, i.e. Figure 2 The relative displacement in the left and right directions. The second limiting hole 71 is composed of a third arc-shaped groove 711 formed on the upper surface of the ear plate 23 and a corresponding fourth arc-shaped groove 712 formed on the lower surface of the base plate 21.

[0072] The third limiting structure is provided on the side plate 22, including a third limiting hole 81 and a third limiting rod 82 inserted therein. The extension direction of the third limiting hole 81 is perpendicular to the bottom plate 21, and it is used to limit the relative displacement of adjacent single battery cells 1 in a direction parallel to the bottom plate 21.

[0073] The surfaces of the first bipolar plate 2, the second bipolar plate 3, and the third bipolar plate 4 are all engraved with anode and cathode channels 9, and each is provided with a channel inlet 91 and a channel outlet 92 that communicate with the anode and cathode channels 9. The channel inlet 91 and the channel outlet 92 provided on the three are aligned with each other.

[0074] In this embodiment, the first bipolar plate 2, the second bipolar plate 3, the third bipolar plate 4, the first limiting rod 62, the second limiting rod 72, and the third limiting rod 82 are all made of graphite.

[0075] The assembly process in this embodiment is as follows:

[0076] The second bipolar plate 3 is slid into the first receiving cavity 24 of the first bipolar plate 2 from the side. The first arc-shaped groove 611 on the lower surface of the ear plate 23 and the second arc-shaped groove 612 on the upper surface of the second bipolar plate 3 are aligned to form the first limiting hole 61. The first limiting rod 62 is inserted into the first limiting hole 61 to achieve the anchoring effect. Then, the third bipolar plate 4 is slid into the second receiving cavity 25 above the second bipolar plate 3 from the side, completing the assembly of a single battery unit 1.

[0077] Two single battery units 1 are stacked together. The third arc-shaped groove 711 on the upper surface of the ear plate 23 and the fourth arc-shaped groove 712 on the lower surface of the base plate 21 are connected to form the second limiting hole 71. The second limiting rod 72 is inserted into the second limiting hole 71 to achieve the anchoring effect.

[0078] The single battery unit 1 is stacked to a set height, and the third limiting hole 81 of each layer of the first bipolar plate 2 is aligned. Then, the third limiting rod 82 is inserted into the third limiting hole 81 to achieve overall anchoring.

[0079] In the description of this utility model, it should be understood that the terms "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this utility model, and do not imply or require that the device or element referred to have a specific orientation or construction method, and therefore should not be construed as a limitation on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish the objects of description and should not be construed as limiting importance or order, and the features defined by such terms may explicitly or implicitly include one or more of those features. Unless otherwise stated, "a plurality of" in the description of this utility model refers to two or more.

[0080] The terms "installation," "connection," and "joining" should be interpreted broadly, unless otherwise explicitly defined, to include, but are not limited to, fixed connections, detachable connections, or integrally formed connections; mechanical or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art can understand their meaning based on the specific technical solution. The fixed connections involved in this utility model, unless otherwise stated, include both detachable fixed connections (such as bolt and screw connections) and non-detachable fixed connections (such as riveting and welding), and may also include integral structures achieved through an integral forming process (such as casting) (except where integral forming is clearly impossible).

[0081] Unless otherwise stated, the terms used in any of the technical solutions disclosed in this utility model to indicate positional relationships or shapes cover states or shapes that are similar to, close to, or adjacent to them.

[0082] Any component provided by this utility model can be assembled from multiple individual components, or it can be a single component manufactured by a one-piece molding process.

[0083] It should be noted that the structures, proportions, sizes, etc., depicted in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which this utility model can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that this utility model can produce, should still fall within the scope of the technical content disclosed in this utility model.

[0084] In the embodiments of this application, the same reference numerals are used to denote the same component or part.

[0085] Any adaptive changes made according to actual needs are within the protection scope of this utility model.

[0086] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. An air-cooled fuel cell stack structure, characterized in that, Includes stacked single-cell units (1), each single-cell unit (1) comprising: The first bipolar plate (2) has a base plate (21), two side plates (22) perpendicular to the base plate (21), and ear plates (23) respectively disposed at the ends of the side plates (22); the two ear plates (23) are parallel to the base plate (21) and extend inward; The first receiving cavity (24) is formed by the line connecting the lower surfaces of the two ear plates (23), the upper surface of the bottom plate (21), and the inner surfaces of the two side plates (22); The second receiving cavity (25) is formed by the line connecting the upper and lower surfaces of the two ear plates (23) and the inner side surface of the ear plates (23); The second bipolar plate (3) is placed on the bottom plate (21) and located in the first receiving cavity (24), and is in contact with the side plate (22) and the ear plate (23); The third bipolar plate (4) is placed on the second bipolar plate (3) and located in the second receiving cavity (25), and is in contact with the two ear plates (23); A single-cell membrane electrode (5) is sandwiched between the base plate (21) and the second bipolar plate (3), and between the second bipolar plate (3) and the third bipolar plate (4).

2. The air-cooled fuel cell stack structure according to claim 1, characterized in that: It also includes a first limiting structure disposed at the contact point between the second bipolar plate (3) and the ear plate (23) for limiting the relative displacement between the two in the extension direction of the ear plate (23).

3. The air-cooled fuel cell stack structure according to claim 2, characterized in that: The first limiting structure includes a first limiting hole (61) opened at the fitting point and a first limiting rod (62) inserted therein, wherein the extending direction of the first limiting hole (61) forms an angle with the extending direction of the ear plate (23).

4. The air-cooled fuel cell stack structure according to claim 3, characterized in that: The first limiting hole (61) is formed by the docking of the first arc-shaped groove (611) on the lower surface of the ear plate (23) and the corresponding second arc-shaped groove (612) on the upper surface of the second bipolar plate (3).

5. The air-cooled fuel cell stack structure according to claim 1, characterized in that: It also includes a second limiting structure located at the joint of adjacent single battery cells (1) to limit the relative displacement of the two in the extension direction of the ear plate (23).

6. The air-cooled fuel cell stack structure according to claim 5, characterized in that: The second limiting structure includes a second limiting hole (71) opened at the fitting point and a second limiting rod (72) inserted therein, wherein the extending direction of the second limiting hole (71) forms an angle with the extending direction of the ear plate (23).

7. The air-cooled fuel cell stack structure according to claim 6, characterized in that: The second limiting hole (71) is formed by the connection of the third arc-shaped groove (711) on the upper surface of the ear plate (23) and the corresponding fourth arc-shaped groove (712) on the lower surface of the base plate (21).

8. The air-cooled fuel cell stack structure according to claim 1, characterized in that: It also includes a third limiting structure provided on the side plate (22) for limiting the relative displacement of adjacent single battery cells (1) in a direction parallel to the bottom plate (21).

9. The air-cooled fuel cell stack structure according to claim 8, characterized in that: The third limiting structure (10) includes a third limiting hole (81) and a third limiting rod (82) inserted therein, wherein the extension direction of the third limiting hole (81) is perpendicular to the base plate (21).

10. The air-cooled fuel cell stack structure according to claim 1, characterized in that: The first bipolar plate (2), the second bipolar plate (3) and the third bipolar plate (4) are all engraved with anode and cathode channels (9), and each is provided with a channel inlet (91) and channel outlet (92) communicating with the anode and cathode channels (9). The channel inlet (91) and channel outlet (92) provided on the three are aligned with each other.

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