Fuel cell stack

Abstract

The fuel cell stack is formed by sequentially stacking a single cell unit and a membrane electrode, and the single cell unit comprises a first bipolar plate, a second bipolar plate, a single cell membrane electrode and a buckle; the monocell membrane electrode is arranged between the first bipolar plate and the second bipolar plate, positioning holes are formed in the first bipolar plate, the second bipolar plate and the monocell membrane electrode, the buckle comprises an upper transverse plate, a lower transverse plate, a positioning column and a connecting block, the upper transverse plate is connected with the lower transverse plate through the connecting block, and the positioning column is vertically arranged on the lower transverse plate; the positioning column penetrates through the first bipolar plate, the second bipolar plate and the single battery membrane electrode to position the first bipolar plate, the second bipolar plate and the single battery membrane electrode of the single battery.

Description

Technical Field

[0001] The utility model belongs to the technical field of fuel cells and relates to a novel fuel cell assembly process. Background Art

[0002] When fuel cells are stacked, the conventional stacking method completely separates the membrane electrode and bipolar plate of a single cell. When the limited position tool is used to press the stack, due to the high pressure, each bipolar plate and membrane electrode of a single cell will be slightly displaced. When the displacement reaches a certain level, it will cause technical problems such as misalignment of the gas flow channel, thus affecting the consistency of the stack performance, and at the same time affecting the neatness and beauty of the stack, reducing the yield rate of the stack production. Utility Model Content

[0003] In view of this, the utility model discloses a fuel cell stack, and the specific scheme is as follows:

[0004] A fuel cell stack, comprising a single cell unit, wherein the single cell unit comprises a first bipolar plate, a second bipolar plate, a single cell membrane electrode, and a buckle;

[0005] The single cell membrane electrode is arranged between the first bipolar plate and the second bipolar plate, the first bipolar plate is provided with a first bipolar plate positioning hole, the second bipolar plate is provided with a second bipolar plate positioning hole, the single cell membrane electrode is provided with a single cell membrane electrode positioning hole, and the first bipolar plate positioning hole, the second bipolar plate positioning hole, and the single cell membrane electrode positioning hole are located in the same vertical direction;

[0006] The buckle includes an upper horizontal plate, a lower horizontal plate, a positioning column, and a connecting block. The upper horizontal plate is located above the lower horizontal plate, and one end of the upper horizontal plate and the lower horizontal plate in the length direction are connected by a connecting block. The positioning column is vertically arranged on the lower horizontal plate; the first bipolar plate, the single cell membrane electrode, and the second bipolar plate are located between the upper horizontal plate and the lower horizontal plate of the buckle, and the positioning column of the buckle is located in the first bipolar plate positioning hole, the second bipolar plate positioning hole, and the single cell membrane electrode positioning hole. The outer periphery of the positioning column of the buckle fits with the inner periphery of the first bipolar plate positioning hole, the second bipolar plate positioning hole, and the single cell membrane electrode positioning hole.

[0007] As a supplement to the technical solution of the utility model, the edge of the single cell membrane electrode is provided with a single cell membrane electrode limiting slot for inserting a connecting block of a buckle, the edge of the first bipolar plate is provided with a first bipolar plate limiting slot for inserting a connecting block of a buckle, and the edge of the second bipolar plate is provided with a second bipolar plate limiting slot for inserting a connecting block of a buckle;

[0008] The first bipolar plate limiting slot, the single cell membrane electrode limiting slot, and the second bipolar plate limiting slot are located in the same vertical direction, and the buckle connecting block is located in the first bipolar plate limiting slot, the single cell membrane electrode limiting slot, and the second bipolar plate limiting slot.

[0009] As a supplement to the technical solution of the utility model, the fuel cell stack also includes a membrane electrode, and the fuel cell stack is formed by stacking a single cell unit and a membrane electrode in sequence;

[0010] The membrane electrode is provided with a membrane electrode positioning hole.

[0011] A columnar protrusion is arranged on the upper end surface of the upper transverse plate of the buckle, and the columnar protrusion is located in the membrane electrode positioning hole of the membrane electrode arranged above the buckle.

[0012] As a supplement to the technical solution of the utility model, the height of the columnar protrusion on the upper horizontal plate of the buckle is greater than the thickness of the membrane electrode, and a columnar groove is provided on the lower end surface of the lower horizontal plate of the buckle;

[0013] The columnar protrusion on the upper horizontal plate of the buckle of the single battery unit passes through the membrane electrode positioning hole and is inserted into the columnar groove on the lower horizontal plate of the buckle located above the single battery unit.

[0014] As a supplement to the technical solution of the utility model, a first groove is provided on the first bipolar plate at a position in contact with the upper horizontal plate of the buckle, the depth of the first groove is the same as the thickness of the upper horizontal plate of the buckle, the upper horizontal plate of the buckle is located in the first groove, and the first bipolar plate positioning hole is located in the first groove;

[0015] A second groove is provided on the second bipolar plate at the contact position with the lower horizontal plate of the buckle. The depth of the second groove is the same as the thickness of the lower horizontal plate of the buckle. The lower horizontal plate of the buckle is located in the second groove, and the second bipolar plate positioning hole is located in the second groove.

[0016] As a supplement to the technical solution of the utility model, the upper horizontal plate of the buckle is elastic, and the upper end of the positioning column is not fixedly connected to the upper horizontal plate.

[0017] As a supplement to the technical solution of the utility model, the buckle is entirely made of polypropylene.

[0018] Beneficial effects: The utility model optimizes the structure of a single cell, reduces the displacement that occurs when the stack is pressed, and increases the integration of the stack assembly. The design of the columnar protrusions and columnar grooves on the buckle enables pre-connection between battery cells to prevent horizontal displacement. When a single battery cell in a fuel cell stack fails and needs to be replaced, the single battery cell stack above the faulty single cell unit is removed and the faulty single battery cell is replaced. Since the single battery cells are connected by buckles, relative horizontal displacement does not occur during reassembly, and there is no need to re-stack the bipolar plates and membrane electrodes one by one. Before assembling the fuel cell stack, the battery cells can be assembled in batches in advance and stored separately. When stacking, single battery cells can be used directly instead of stacking them one by one, which increases the stacking speed by 2 to 3 times. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the structure of a single battery unit of the utility model.

[0020] Figure 2 This is a schematic diagram of the explosion structure of a single battery unit of the utility model.

[0021] Figure 3 This is a bottom view of the structure of the second bipolar plate of the utility model.

[0022] Figure 4 This is a schematic diagram of the buckle structure of the utility model.

[0023] Figure 5 This is a schematic diagram of the buckle structure of the utility model.

[0024] Figure 6 This is a schematic diagram of the explosion structure of the single battery unit and membrane electrode assembly of the utility model.

[0025] In the figure: 1. single battery unit, 2. first bipolar plate, 3. second bipolar plate, 4. single battery membrane electrode, 5. buckle, 6. upper horizontal plate, 7. lower horizontal plate, 8. positioning column, 9. connecting block, 10. first bipolar plate positioning hole, 11. second bipolar plate positioning hole, 12. single battery membrane electrode positioning hole, 13. single battery membrane electrode limiting slot, 14. membrane electrode positioning hole, 15. columnar protrusion, 16. columnar groove, 17. first groove, 18. second groove, 19. first bipolar plate limiting slot, 20. second bipolar plate limiting slot, 21. membrane electrode. DETAILED DESCRIPTION

[0026] In the description of the present invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0027] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the prior art, when assembling a fuel cell stack, the cathode plate and the anode plate are first assembled into a bipolar plate, and then a single cell membrane electrode 4 is clamped between the two bipolar plates. The bipolar plates and the single cell membrane electrode 4 are stacked in sequence to form a fuel cell stack, and then the stacking process is performed by limiting the position of the tooling. The utility model is to solve the problem of misalignment between the bipolar plate and the single cell membrane electrode 4 during the stacking process, which affects the performance of the fuel cell stack. A new fuel cell stack is disclosed, such as Figures 1 to 6 As shown, it includes a single battery unit 1, and the single battery unit 1 includes a bipolar plate, a single battery membrane electrode 4, and a buckle 5.

[0029] The single cell unit 1 has two groups of bipolar plates, namely a first bipolar plate 2 and a second bipolar plate 3, and the single cell membrane electrode 4 is arranged between the two groups of bipolar plates. The bipolar plate is composed of two stacked and welded monopolar plates.

[0030] The first bipolar plate 2 is provided with a first bipolar plate positioning hole 10, the second bipolar plate 3 is provided with a second bipolar plate positioning hole 11, and the single cell membrane electrode 4 is provided with a single cell membrane electrode positioning hole 12. The first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12 correspond to each other, so that when stacked to form a single cell unit 1, the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12 are located in the same vertical direction, so that the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12 are connected. Specifically, the centers of the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12 are located on the same vertical straight line.

[0031] The buckle 5 includes an upper transverse plate 6 , a lower transverse plate 7 , a positioning column 8 , and a connecting block 9 .

[0032] The upper transverse plate 6 and the lower transverse plate 7 are arranged relatively parallel, the upper transverse plate 6 is located above the lower transverse plate 7, and one end of the upper transverse plate 6 and the lower transverse plate 7 in the length direction is connected by a connecting block 9. A positioning column 8 for limiting the first bipolar plate 2, the second bipolar plate 3, and the single cell membrane electrode 4 is provided between the upper transverse plate 6 and the lower transverse plate 7. The positioning column 8 is vertically arranged on the lower transverse plate 7 of the buckle 5, and the lower end of the positioning column 8 is fixedly connected to the lower transverse plate 7.

[0033] The first bipolar plate 2, the single cell membrane electrode 4, and the second bipolar plate 3 are located between the upper horizontal plate 6 and the lower horizontal plate 7 of the buckle 5, and the positioning column 8 is located in the positioning holes of the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12. The outer periphery of the positioning column 8 of the buckle 5 fits with the inner periphery of the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11, and the single cell membrane electrode positioning hole 12, and the single cell unit 1 is limited by the positioning column 8 of the buckle 5.

[0034] Due to the presence of the buckle 5, the assembled single cell unit 1 limits the first bipolar plate 2, the single cell membrane electrode 4, and the second bipolar plate 3, thereby preventing the technical problem of the first bipolar plate 2, the single cell membrane electrode 4, and the second bipolar plate 3 being misaligned when subjected to force during the stacking process. The utility model optimizes the structure of the single cell, reduces the offset that occurs when the stack is pressed, and increases the integration of the stack assembly. When a single cell unit 1 in the fuel cell stack fails and needs to be replaced, the single cell unit 1 stack above the failed cell unit is removed, and the failed single cell unit 1 is replaced. Since the single cell units 1 are connected by the buckle 5, it is ensured that there will be no relative horizontal displacement during reassembly, and there is no need to re-stack the bipolar plates and membrane electrodes one by one. Before the fuel cell stack is assembled, the battery units can be assembled in batches in advance and stored separately. When stacking, the single cell unit 1 is directly used instead of stacking one by one, which increases the stacking speed by 2 to 3 times.

[0035] As a supplement to the above technical solution, the structures of the first bipolar plate positioning hole 10, the second bipolar plate positioning hole 11 and the single cell membrane electrode positioning hole 12 can be any structure, preferably a circular structure.

[0036] As a preferred technical solution of the utility model, a single cell membrane electrode positioning slot 13 is provided at the outer edge of the single cell membrane electrode 4. The single cell membrane electrode positioning slot 13 is a groove opened at the outer edge of the single cell membrane electrode 4 toward the middle of the single cell membrane electrode 4. The single cell membrane electrode positioning slot 13 is used for inserting the connecting block 9 of the buckle 5.

[0037] A first bipolar plate limiting slot 19 is provided at the outer edge of the first bipolar plate 2. The first bipolar plate limiting slot 19 is a groove opened at the outer edge of the first bipolar plate 2 toward the middle of the first bipolar plate 2. The first bipolar plate limiting slot 19 is used for inserting the connecting block 9 of the buckle 5.

[0038] A second bipolar plate limiting slot 20 is provided at the outer edge of the second bipolar plate 3. The second bipolar plate limiting slot 20 is a groove opened at the outer edge of the second bipolar plate 3 toward the middle of the second bipolar plate 3. The second bipolar plate limiting slot 20 is used for inserting the connecting block 9 of the buckle 5.

[0039] The first bipolar plate limiting slot 19, the single cell membrane electrode limiting slot 13, and the second bipolar plate limiting slot 20 correspond to each other, so that when stacked to form a single cell unit 1, the first bipolar plate limiting slot 19, the single cell membrane electrode limiting slot 13, and the second bipolar plate limiting slot 20 are located in the same vertical direction, so that the connecting block 9 of the buckle 5 can be smoothly inserted into the above three slots. After assembly, the connecting block 9 of the buckle 5 is located in the first bipolar plate limiting slot 19, the single cell membrane electrode limiting slot 13, and the second bipolar plate limiting slot 20, further improving the limiting effect of the buckle 5 on the single cell membrane electrode 4 and the bipolar plate.

[0040] The design of the first bipolar plate limiting slot 19, the single cell membrane electrode limiting slot 13, and the second bipolar plate limiting slot 20 can form a mortise and tenon structure with the buckle 5, thereby improving the structural stability and increasing the overall aesthetics.

[0041] Since the upper horizontal plate 6 and the lower horizontal plate 7 of the clip 5 have a certain thickness, when the fuel cell stack is assembled, the thickness of the upper horizontal plate 6 / lower horizontal plate 7 of the clip 5 is separated between adjacent single battery units 1 and membrane electrode 21. As the number of clips 5 increases, the single battery units 1 and membrane electrode 21 will be deformed during the stacking process.

[0042] As a preferred technical solution of the utility model, a first groove 17 is provided on the first bipolar plate 2 at a position in contact with the upper horizontal plate 6 of the buckle 5, the depth of the first groove 17 is the same as the thickness of the upper horizontal plate 6 of the buckle 5, and the upper horizontal plate 6 of the buckle 5 is located in the first groove 17. A second groove 18 is provided on the second bipolar plate 3 at a position in contact with the lower horizontal plate 7 of the buckle 5, the depth of the second groove 18 is the same as the thickness of the lower horizontal plate 7 of the buckle 5, and the lower horizontal plate 7 of the buckle 5 is located in the second groove 18.

[0043] The first bipolar plate positioning hole 10 is located in the first groove 17. Figure 2 As shown, the first bipolar plate positioning hole 10 is a hole opened at the bottom of the first groove 17. The second bipolar plate positioning hole 11 is located in the second groove 18, as shown in FIG. Figure 3 As shown, the second bipolar plate positioning hole 11 is a hole opened at the bottom of the second groove 18. Accordingly, the first bipolar plate limiting slot 19 is located in the first groove 17, and the second bipolar plate limiting slot is located in the second groove 18.

[0044] Through the above-mentioned arrangement, the buckle 5 is completely embedded in the single battery unit 1, and the distance between the upper end surface of the upper horizontal plate 6 of the buckle 5 and the lower end surface of the lower horizontal plate 7 is equal to the distance between the upper end surface of the first bipolar plate 2 and the lower end surface of the second bipolar plate 3, thereby avoiding the occurrence of technical problems of stack deformation.

[0045] As a preferred technical solution of the utility model, the buckles 5 of the single battery unit 1 are provided with two groups, and the two groups of buckles 5 are arranged on the single battery unit 1 in a centrally symmetrical form. Figure 1 As shown, the first buckle 5 is located at the left end of the single battery unit 1, and the second buckle 5 is located at the right end of the single battery unit 1. Buckles 5 can be provided in multiple groups according to actual use requirements. Considering factors such as processing cost and limiting effect, two groups are sufficient.

[0046] As a preferred technical solution of the present invention, the fuel cell stack further includes a membrane electrode 21, and the fuel cell stack is formed by stacking the single cell unit 1 and the membrane electrode 21 in sequence. The membrane electrode 21 and the single cell membrane electrode 4 are actually the same component. In the present invention, the single cell membrane electrode 4 in the single cell unit 1 is distinguished from the membrane electrode 21 between two adjacent single cell units 1, and the membrane electrode 21 in the single cell unit 1 is limited in name.

[0047] The membrane electrode 21 is provided with a membrane electrode positioning hole 14 , and the upper end surface of the upper horizontal plate 6 of the buckle 5 is provided with a columnar protrusion 15 , and the columnar protrusion 15 is located in the membrane electrode positioning hole 14 of the membrane electrode 21 arranged above the buckle 5 .

[0048] Through the above arrangement, the buckle 5 on the single battery unit 1 can limit the membrane electrode 21 located above the single battery unit 1 .

[0049] In the above technical solution, there is no direct connection between the membrane electrodes 21 of the fuel cell stack. During the fuel cell stack compression process, there will still be a problem of misalignment between the single cell unit 1 and the membrane electrode 21. In view of this, the height of the columnar protrusion 15 on the upper end surface of the upper horizontal plate 6 of the buckle 5 is greater than the thickness of the membrane electrode 21, and a columnar groove 16 is provided on the lower end surface of the lower horizontal plate 7 of the buckle 5. The columnar protrusion 15 on the upper horizontal plate 6 of the buckle 5 of the single cell unit 1 passes through the membrane electrode positioning hole 14 and is inserted into the columnar groove 16 on the lower horizontal plate 7 of the buckle 5 located above the single cell unit 1, so as to realize the mutual connection between the single cell units 1 on the fuel cell stack and avoid the misalignment problem caused during the compression process.

[0050] As a preferred technical solution of the utility model, in order to improve the assembly efficiency between the buckle 5 and the first bipolar plate 2, the single cell membrane electrode 4, and the second bipolar plate 3, the upper horizontal plate 6 is made of a flexible material, and the upper end of the positioning column 8 is not fixedly connected to the upper horizontal plate 6. When assembling the single battery unit 1, since the upper horizontal plate 6 of the buckle 5 is elastic, the assembler can move the upper horizontal plate 6 of the buckle 5 to increase the separation distance between the upper horizontal plate 6 and the upper end of the positioning column 8, and then insert the first bipolar plate 2, the single cell membrane electrode 4, and the second bipolar plate 3 into the upper horizontal plate 6 and the lower horizontal plate 7 of the buckle 5 in sequence, and at the same time pass the positioning column 8 through the positioning holes on the first bipolar plate 2, the second bipolar plate 3, and the single cell membrane electrode 4, and assemble the single battery unit 1 through the above steps.

[0051] The buckle 5 can be made of a flexible material as a whole, and can be made of polypropylene specifically.

[0052] The above is only a preferred specific implementation method of the utility model, but the protection scope of the utility model is not limited to it. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and utility model concept of the utility model within the technical scope disclosed by the utility model, which should be covered by the protection scope of the utility model.

Claims

1. A fuel cell stack, It is characterized in that It comprises a single battery unit (1), wherein the single battery unit (1) comprises a first bipolar plate (2), a second bipolar plate (3), a single battery membrane electrode (4), and a buckle (5); The single cell membrane electrode (4) is arranged between the first bipolar plate (2) and the second bipolar plate (3); the first bipolar plate (2) is provided with a first bipolar plate positioning hole (10); the second bipolar plate (3) is provided with a second bipolar plate positioning hole (11); the single cell membrane electrode (4) is provided with a single cell membrane electrode positioning hole (12); the first bipolar plate positioning hole (10), the second bipolar plate positioning hole (11), and the single cell membrane electrode positioning hole (12) are located in the same vertical direction; The buckle (5) comprises an upper transverse plate (6), a lower transverse plate (7), a positioning column (8), and a connecting block (9); the upper transverse plate (6) is located above the lower transverse plate (7); one end of the upper transverse plate (6) and the lower transverse plate (7) in the length direction is connected by the connecting block (9); the positioning column (8) is vertically arranged on the lower transverse plate (7); the first bipolar plate (2), the single cell membrane electrode (4), and the second bipolar plate (3) are located between the upper transverse plate (6) and the lower transverse plate (7) of the buckle (5); and the positioning column (8) of the buckle (5) is located in the first bipolar plate positioning hole (10), the second bipolar plate positioning hole (11), and the single cell membrane electrode positioning hole (12).

2. A fuel cell stack according to claim 1, It is characterized in that The edge of the single cell membrane electrode (4) is provided with a single cell membrane electrode limiting slot (13) for inserting the connecting block (9) of the buckle (5), the edge of the first bipolar plate (2) is provided with a first bipolar plate limiting slot (19) for inserting the connecting block (9) of the buckle (5), and the edge of the second bipolar plate (3) is provided with a second bipolar plate limiting slot (20) for inserting the connecting block (9) of the buckle (5); The first bipolar plate limiting slot (19), the single cell membrane electrode limiting slot (13), and the second bipolar plate limiting slot (20) are located in the same vertical direction, and the connecting block (9) of the buckle (5) is located in the first bipolar plate limiting slot (19), the single cell membrane electrode limiting slot (13), and the second bipolar plate limiting slot (20).

3. A fuel cell stack according to claim 1, It is characterized in that The fuel cell stack further comprises a membrane electrode (21), and the fuel cell stack is formed by stacking a single cell unit (1) and a membrane electrode (21) in sequence; The membrane electrode (21) is provided with a membrane electrode positioning hole (14). A columnar protrusion (15) is provided on the upper end surface of the upper transverse plate (6) of the buckle (5), and the columnar protrusion (15) is located in a membrane electrode positioning hole (14) of a membrane electrode (21) provided above the buckle (5).

4. A fuel cell stack according to claim 3, It is characterized in that The height of the columnar protrusion (15) on the upper horizontal plate (6) of the buckle (5) is greater than the thickness of the membrane electrode (21), and a columnar groove (16) is provided on the lower end surface of the lower horizontal plate (7) of the buckle (5); The columnar protrusion (15) on the upper horizontal plate (6) of the buckle (5) of the single battery unit (1) passes through the membrane electrode positioning hole (14) and is inserted into the columnar groove (16) on the lower horizontal plate (7) of the buckle (5) located above the single battery unit (1).

5. A fuel cell stack according to claim 1, It is characterized in that A first groove (17) is provided on the first bipolar plate (2) at a position where the first bipolar plate (2) contacts the upper transverse plate (6) of the buckle (5); the depth of the first groove (17) is the same as the thickness of the upper transverse plate (6) of the buckle (5); the upper transverse plate (6) of the buckle (5) is located in the first groove (17); and the first bipolar plate positioning hole (10) is located in the first groove (17); A second groove (18) is provided on the second bipolar plate (3) at a position in contact with the lower transverse plate (7) of the buckle (5); the depth of the second groove (18) is the same as the thickness of the lower transverse plate (7) of the buckle (5); the lower transverse plate (7) of the buckle (5) is located in the second groove (18); and the second bipolar plate positioning hole (11) is located in the second groove (18).

6. A fuel cell stack according to claim 1, It is characterized in that The upper horizontal plate (6) of the buckle (5) is elastic, and the upper end of the positioning column (8) is not fixedly connected to the upper horizontal plate (6).

7. A fuel cell stack according to claim 1, It is characterized in that The buckle (5) is entirely made of polypropylene.

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