fuel cell units and fuel cell stacks

Abstract

This invention provides a fuel cell unit and a fuel cell stack. The fuel cell unit includes a set of bipolar plates, a membrane electrode assembly (MEA), and an adhesive layer. The MEA is sandwiched between the set of bipolar plates, and the adhesive layer is disposed between the set of bipolar plates and the MEA, thereby forming an airtight structure between the set of bipolar plates and the MEA to prevent cross-flow or leakage of reactant gases. Thus, this invention achieves an airtight effect with a simplified structure, which not only reduces manufacturing costs and improves overall process yield, but also simplifies the assembly process and improves overall assembly efficiency.

Description

fuel cell units and fuel cell stacks Technical Field

[0001] This invention relates to fuel cell technology, and more particularly to a fuel cell cell and a fuel cell stack. Prior Technology

[0002] In the prior art, a fuel cell stack typically includes multiple fuel cell units, each of which is mainly composed of a membrane electrode assembly (MEA) and a set of bipolar plates. By delivering different reactant gases to the bipolar plates of each fuel cell unit, these reactant gases flow between the set of bipolar plates and the MEA, thereby carrying out an oxidation-reduction reaction to generate electricity.

[0003] To achieve the airtightness requirements inside the fuel cell cell, existing technologies typically form multiple grooves on the bipolar plates and place a plastic gasket in each groove to seal the gap between the membrane electrode and the bipolar plates.

[0004] However, such an airtight structure design not only increases manufacturing costs, but also requires assembly personnel to align each plastic gasket one by one and place it in the corresponding groove during assembly, which makes the assembly operation time-consuming and cumbersome, reducing the overall assembly efficiency. Furthermore, during the assembly process, these plastic gaskets are prone to displacement due to uneven pressure, which reduces or even fails the airtight effect, causing the reactant gases to flow between each other within the fuel cell unit or leak outward, thereby affecting the overall process yield.

[0005] Therefore, it is indeed necessary to propose a better solution to address the problems of the existing technology. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the main objective of this invention is to provide a fuel cell cell and a fuel cell stack that reduce manufacturing costs and improve overall process yield and overall assembly efficiency by improving the airtight structure.

[0007] To achieve the above objectives, the present invention employs a technical means to make the aforementioned fuel cell unit comprise: A set of bipolar plates; A membrane electrode is sandwiched between the bipolar plates; A set of adhesive layers is disposed between the set of bipolar plates and the membrane electrode to form an airtight structure.

[0008] To achieve the above objectives, another technical means adopted by this invention is to make the aforementioned fuel cell stack include multiple fuel cell units as described above, and these fuel cell units are stacked on top of each other.

[0009] Through the above structure, by sandwiching the membrane electrode between the bipolar plates and disposing the adhesive layers between the bipolar plates and the membrane electrode, an airtight structure is formed between the bipolar plates and the membrane electrode to prevent the reaction gases from flowing between each other or leaking outward. Thus, this novel invention achieves an airtight effect with a simplified structure, which not only reduces manufacturing costs and improves the overall process yield, but also simplifies the assembly process and improves the overall assembly efficiency. Simple Explanation of the Diagram

[0010] Figure 1 is a perspective view of the first embodiment of the present invention; Figure 2 is an exploded view of the first embodiment of the present invention; Figure 3 is a partial cross-sectional schematic diagram of the adhesive layer according to the first embodiment of the present invention; Figure 4 is another perspective view of the first embodiment of the present invention; Figure 5 is another exploded view of the first embodiment of the present invention; Figure 6 is a block diagram of an architecture according to a second embodiment of the present invention; Figure 7 is a perspective view of the second embodiment of the present invention; Figure 8 is an exploded view of the second embodiment of the present invention; Figure 9 is a block diagram of a detection architecture according to a second embodiment of the present invention; Figure 10 is an electrical characteristic curve of the second embodiment of the present invention. Implementation

[0011] Regarding the first embodiment of this invention, please refer to Figures 1 and 2, which provide a fuel cell unit 1. The fuel cell unit 1 includes a set of bipolar plates 11, a membrane electrode assembly 12, and a set of adhesive layers 13. The membrane electrode assembly 12 is sandwiched between the set of bipolar plates 11. The membrane electrode assembly 12 is rectangular and has a first side 121 and a second side 122, which are perpendicular to each other. The set of adhesive layers 13 are respectively disposed between the set of bipolar plates 11 and the membrane electrode assembly 12, thereby forming an airtight structure between the set of bipolar plates 11 and the membrane electrode assembly 12 to prevent the reaction gases from flowing between each other or leaking outward. In this way, this invention achieves an airtight effect with a simplified structure, which not only reduces manufacturing costs and improves the overall process yield, but also simplifies the assembly process and improves the overall assembly efficiency.

[0012] Specifically, as shown in Figures 1 and 2, this embodiment further provides a first direction X, a second direction Y, and a third direction Z. The first direction X is parallel to the first side 121 of the membrane electrode 12, the second direction Y is parallel to the second side 122 of the membrane electrode 12, so that the first direction X and the second direction Y are perpendicular to each other, and the third direction Z is perpendicular to the first direction X and the second direction Y.

[0013] In this embodiment, as shown in FIG2, the bipolar plate 11 includes a rectangular first electrode plate 111 and a rectangular second electrode plate 112. The first electrode plate 111 may be composed of a cathode electrode plate. The first electrode plate 111 has a plurality of first gas inlet holes 1111 on both sides in the first direction X. The first gas inlet holes 1111 are arranged at intervals along the second direction Y and penetrate the top and bottom surfaces of the first electrode plate 111 respectively. Furthermore, the top surface of the first electrode plate 111 has a plurality of first gas channels 1112. The first gas channels 1112 are arranged at intervals along the first direction X and extend in a strip shape along the second direction Y respectively.

[0014] The second electrode plate 112 may be composed of an anode electrode plate. The second electrode plate 112 has a plurality of second gas inlet / outlet holes 1121 on both sides in the first direction X. The second gas inlet / outlet holes 1121 are arranged at intervals along the second direction Y, and the positions of the second gas inlet / outlet holes 1121 correspond to the positions of the first gas inlet / outlet holes 1111 of the first electrode plate 111. The second gas inlet / outlet holes 1121 penetrate the top surface and the bottom surface of the second electrode plate 112. Furthermore, the top surface of the second electrode plate 112 has a plurality of second gas flow channels 1122. The second gas flow channels 1122 are extended in a strip shape by bending along the first direction X and the second direction Y.

[0015] In this embodiment, the membrane electrode 12 is sandwiched between the bottom surface of the first electrode plate 111 and the top surface of the second electrode plate 112. The membrane electrode 12 has a plurality of third gas inlet / outlet holes 123 on both sides in the first direction X. The third gas inlet / outlet holes 123 are arranged at intervals along the second direction Y, such that the positions of the third gas inlet / outlet holes 123 correspond to the positions of the first gas inlet / outlet holes 1111 of the first electrode plate 111 and the positions of the second gas inlet / outlet holes 1121 of the second electrode plate 112. The third gas inlet / outlet holes 123 penetrate the top and bottom surfaces of the membrane electrode 12. The third gas inlet / outlet holes 123 are connected in series with the first gas inlet / outlet holes 1111 and the second gas inlet / outlet holes 1121 to form a plurality of channels for the flow of reaction gases within the fuel cell unit 1.

[0016] In this embodiment, the adhesive layer 13 includes a plurality of first adhesive layers 131, a plurality of second adhesive layers 132, and a third adhesive layer 133. The first adhesive layers 131 are frame-shaped and are disposed between the bottom surface of the first electrode plate 111 and the top surface of the membrane electrode 12, respectively, and surround the outer periphery of the first gas inlet / outlet hole 1111 of the first electrode plate 111 and the third gas inlet / outlet hole 123 of the membrane electrode 12. The second adhesive layers 132 are frame-shaped or C-shaped. The second adhesive layer 132 is respectively disposed between the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112, and surrounds the outer periphery of the third gas inlet / outlet hole 123 of the membrane electrode 12 and the second gas inlet / outlet hole 1121 of the second electrode plate 112; the third adhesive layer 133 is frame-shaped, and is disposed between the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112, and surrounds the outer edge of the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112.

[0017] Thus, through the arrangement of the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133, an airtight structure is formed between the first gas inlet / outlet holes 1111 and the third gas inlet / outlet holes 123, between the third gas inlet / outlet holes 123 and the second gas inlet / outlet holes 1121, and between the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112, so as to prevent the reaction gases from flowing into each other or leaking outwards. This replaces the traditional design of using grooves to fit plastic gaskets, thereby achieving the purpose of reducing manufacturing costs.

[0018] Furthermore, during assembly, the assembler can first attach the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133 to the top and bottom surfaces of the membrane electrode 12, respectively. Then, the first electrode plate 111 is attached to the first adhesive layer 131, and the second electrode plate 112 is attached to the second adhesive layer 132 and the third adhesive layer 133. Compared to the assembly method of traditional fuel cell cells, this embodiment can eliminate the additional alignment steps of traditional plastic gaskets, thereby simplifying the assembly process and improving the overall assembly efficiency.

[0019] Furthermore, referring to Figures 2 and 3, in this embodiment, the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133 can each be composed of a foam double-sided adhesive or an elastic double-sided adhesive material; the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133 each include an elastic body 131a, 132a, 133a, an upper adhesive surface 131b, 132b, 133b, and a lower adhesive surface 131c, 132c, 133c; the elastic body 131a, 132a, 133a has a top surface and a bottom surface in the third direction Z; the upper adhesive surface 131b, 132b, 133b is disposed on the top surface of the elastic body 131a, 132a, 133a; the lower adhesive surface 131c, 132c and 133c are disposed on the bottom surface of the elastic body 131a, 132a and 133a.

[0020] The elastic body 131a is bonded to the outer periphery of the first gas inlet / outlet hole 1111 of the first electrode plate 111 and the third gas inlet / outlet hole 123 of the membrane electrode 12 through the upper adhesive surface 131b and the lower adhesive surface 131c. The elastic body 132a is bonded to the outer periphery of the third gas inlet / outlet hole 123 of the membrane electrode 12 and the second gas inlet / outlet hole 1121 of the second electrode plate 112 through the upper adhesive surface 132b and the lower adhesive surface 132c. The elastic body 133a is bonded to the outer edge of the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112 through the upper adhesive surface 133b and the lower adhesive surface 133c.

[0021] During assembly, when the first electrode plate 111, the membrane electrode 12, and the second electrode plate 112 are subjected to an assembly pressure along the third direction Z, the adhesion of the upper adhesive surfaces 131b, 132b, 133b and the lower adhesive surfaces 131c, 132c, 133c of the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133 will be activated, and they will adhere to the bottom surface of the first electrode plate 111, the top and bottom surfaces of the membrane electrode 12, and the top surface of the second electrode plate 112, thus fixing the first electrode plate 111, the membrane electrode 12, and the second electrode plate 112 together. Furthermore, the elastic bodies 131a, 132a of the first adhesive layer 131, the second adhesive layer 132, and the third adhesive layer 133 will also be activated. 133a will form an airtight structure between the first gas inlet / outlet 1111 and the third gas inlet / outlet 123, between the third gas inlet / outlet 123 and the second gas inlet / outlet 1121, and between the bottom surface of the membrane electrode 12 and the top surface of the second electrode plate 112, so as to prevent the reaction gases from flowing into each other or leaking outward.

[0022] As shown in Figure 3, in this embodiment, on the third direction Z, there is a thickness Ta, Tb, Tc between the top and bottom surfaces of the elastic bodies 131a, 132a, 133a. For example, the thickness Ta, Tb, Tc can be between 0.8 mm and 1 mm.

[0023] Please refer to Figures 4 and 5. In this embodiment, the fuel cell unit 1 may further include a plurality of frame-shaped connecting adhesive layers 14. These connecting adhesive layers 14 are respectively disposed on the top surface of the first electrode plate 111 and surround the outer periphery of the first gas inlet / outlet hole 1111 of the first electrode plate 111. Thus, when a second electrode plate (not shown) of another fuel cell unit is stacked above the top surface of the first electrode plate 111, the first electrode plate 111 can be bonded to the second electrode plate of the other fuel cell unit through the connecting adhesive layers 14, so that the fuel cell unit 1 and the other fuel cell unit are fixedly connected to each other, and an airtight structure is formed between the first electrode plate 111 and the second electrode plate of the other fuel cell unit to further prevent the reaction gases from flowing into each other or leaking outward.

[0024] Regarding the second embodiment of this invention, please refer to Figure 6. Its main technical content is largely the same as that of the first embodiment, except that the second embodiment further provides a fuel cell stack 2. In this embodiment, the fuel cell stack 2 includes a plurality of fuel cell cells 1, and these fuel cell cells 1 are stacked on top of each other.

[0025] To further illustrate the specific structure of the fuel cell stack 2, please refer to Figures 7 and 8. In this embodiment, the fuel cell stack 2 further includes a set of end plates 21, a set of insulating plates 22, a set of current collectors 23, a plurality of limiting members 24, and a plurality of fixing members 25. The fuel cell units 1 are sandwiched between the end plates 21, and the outer edges of the end plates 21 each have a plurality of fixing holes 211. The insulating plates 22 are respectively disposed between the end plates 21 and the fuel cell units 1. The current collectors 23 are respectively disposed between the insulating plates 22 and the fuel cell units 1. The limiting members 24 are respectively disposed between the end plates 21 and the fuel cell units 1. The fixing holes 211 of the end plate 21 are inserted into the fixing holes 211 and surround the fuel cell cells 1, the insulating plate 22, and the current collector 23 to limit the fuel cell cells 1, the insulating plate 22, and the current collector 23 between the end plate 21 and the limiting members 24, wherein each limiting member 24 may be constituted by a bolt; the fixing members 25 are respectively fixedly disposed on the limiting members 24 to lock and fix the limiting members 24 to the end plate 21 and to apply an assembly downward pressure to the fuel cell cells 1 by the end plate 21, wherein each fixing member 25 may be constituted by a nut.

[0026] To test the airtightness of the fuel cell stack 2, please refer to Figure 9. In this embodiment, a detection gas source 31, a pressure regulating valve 32, a first switch 33, a first adapter 34, a first quick connector 35, a second quick connector 36, a second adapter 37, a pressure gauge 38, and a second switch 39 are further provided. The detection gas source 31 can be connected to the end plate 21 of the fuel cell stack 2 in sequence through the pressure regulating valve 32, the first switch 33, the first adapter 34, and the first quick connector 35. The end plate 21 of the fuel cell stack 2 can be connected to the second switch 39 in sequence through the second quick connector 36, the second adapter 37, and the pressure gauge 38.

[0027] During the testing process, the testing gas provided by the testing gas source 31 can sequentially pass through the pressure regulating valve 32, the first switch 33, the first adapter 34, the first quick connector 35, the end plate 21, the insulating plate 22, and the current collector 23 of the fuel cell stack 2 into the channels within the individual fuel cell cells 1, and then sequentially pass through the current collector 23, the insulating plate 22, the end plate 21, the second quick connector 36, the second adapter 37, the pressure gauge 38, and the second switch 39 of the fuel cell stack 2. In this way, the testing personnel can adjust the pressure value of the testing gas provided by the testing gas source 31 and read the value of the pressure gauge 38 to instantly test the airtightness of the fuel cell stack 2. For example, the testing gas source 31 can be composed of a hydrogen cylinder, and the testing gas can be hydrogen.

[0028] To further illustrate how the second embodiment described above, through its configuration, can improve the electrical performance of the fuel cell stack after multiple activation stages, please refer to Figure 10. In Figure 10, the dashed line C1 shows the relationship between current and power measured after one activation stage in the second embodiment; the solid line C2 shows the relationship between current and power measured after nine activation stages in the second embodiment; the dashed line C3 shows the relationship between current and voltage measured after one activation stage in the second embodiment; and the solid line C4 shows the relationship between current and voltage measured after nine activation stages in the second embodiment. Each activation stage uses an activation voltage with an average voltage value of 0.6 volts (V) to activate the second embodiment.

[0029] As shown in Figure 10, the second embodiment, after nine activation stages, generates a current of 18 amperes (A) and a maximum power of 430 watts (W). Compared to the maximum power generated by the second embodiment after only one activation stage, the maximum power of the second embodiment after nine activation stages is increased by 70%. Therefore, the configuration proposed in the second embodiment can improve the electrical performance of the fuel cell stack after multiple activation stages.

[0030] 1: Fuel cell 11: Bipolar plate 111: First electrode plate 1111: First gas inlet / outlet port 1112: First gas flow channel 112: Second electrode plate 1121: Second gas inlet / outlet port 1122: Second gas flow channel 12: Membrane Electrode 121: First side 122: Second side 123: Third gas inlet / outlet port 13: Adhesive layer 131: First adhesive layer 132: Second adhesive layer 133: Third adhesive layer 131a, 132a, 133a: Elastic body 131b, 132b, 133b: Top adhesive surface 131c, 132c, 133c: Lower adhesive surface Ta, Tb, Tc: Thickness 14: Connecting Adhesive Layer 2: Fuel Cell Stack 21: End plate 211: Fixing hole 22: Insulation board 23: Current collector 24: Limiting component 25: Fasteners 31: Detecting the gas source 32: Pressure regulating valve 33: First Switch 34: First adapter 35: First quick connector 36: Second quick connector 37: Second adapter 38: Pressure gauge 39: Second Switch C1: Dashed line C2: Solid line C3: Dashed line C4: Solid line X: First direction Y: Second direction Z: Third-party direction

Claims

1. A fuel cell unit, comprising: A set of bipolar plates; a membrane electrode sandwiched between the set of bipolar plates; A set of adhesive layers is disposed between the set of bipolar plates and the membrane electrode to form an airtight structure.

2. The fuel cell unit as described in claim 1, wherein, The bipolar plate assembly includes: a first electrode plate having a plurality of first gas inlet / outlet holes on both sides; a second electrode plate having a plurality of second gas inlet / outlet holes on both sides; wherein, the membrane electrode has a plurality of third gas inlet / outlet holes on both sides, the positions of which correspond to the positions of the first gas inlet / outlet holes on the first electrode plate and the positions of the second gas inlet / outlet holes on the second electrode plate, respectively.

3. The fuel cell unit as described in claim 2, wherein, The adhesive layer group includes: a plurality of first adhesive layers, which are disposed between the first electrode plate and the membrane electrode, and respectively at the first gas inlet / outlet hole of the first electrode plate and the third gas inlet / outlet hole of the membrane electrode.

4. The fuel cell unit as described in claim 2, wherein, The adhesive layer group includes: a plurality of second adhesive layers, which are disposed between the membrane electrode and the second electrode plate, and respectively at the third gas inlet / outlet of the membrane electrode and the second gas inlet / outlet of the second electrode plate.

5. The fuel cell unit as described in claim 2, wherein, The adhesive layer group includes: a third adhesive layer disposed between the membrane electrode and the second electrode plate, and surrounding the outer edge of the membrane electrode and the second electrode plate.

6. The fuel cell unit as described in claim 1, wherein, The adhesive layers include: an elastic body; an upper adhesive surface disposed on the top surface of the elastic body; and a lower adhesive surface disposed on the bottom surface of the elastic body; wherein the elastic body is bonded between the bipolar plate and the membrane electrode through the upper adhesive surface and the lower adhesive surface.

7. The fuel cell unit as described in claim 1, wherein, The adhesive layers consist of either a foam double-sided adhesive or a flexible double-sided adhesive material.

8. A fuel cell stack comprising: A plurality of fuel cell cells as described in any one of claims 1 to 7, wherein such fuel cell cells are stacked on top of each other.

9. The fuel cell stack as described in claim 8, wherein, It further includes a plurality of bonding adhesive layers disposed on the fuel cell cells to secure the fuel cell cells together.

10. The fuel cell stack as described in claim 8, wherein, The fuel cell stack further includes: a set of end plates sandwiching the fuel cell cells; a set of insulating plates disposed between the end plates and the fuel cell cells; a set of current collectors disposed between the insulating plates and the fuel cell cells; a plurality of limiting members passing through the end plates and surrounding the fuel cell cells, the insulating plates, and the current collectors; and a plurality of fixing members disposed on the limiting members to fix the limiting members to the end plates.

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