A metal bipolar plate and air-cooled proton exchange membrane fuel cell

Abstract

The present invention relates to a metal bipolar plate and an air-cooled proton exchange membrane fuel cell. The metal bipolar plate used for the air-cooled proton exchange membrane fuel cell includes an anode plate and a cathode plate stacked up and down. The middle section of the cathode plate is a corrugated plate. Each groove of the corrugated plate is used as a gas channel. All gas channels horizontally penetrate the cathode plate. A plurality of through holes are distributed on the corrugated plate, and each through hole penetrates two adjacent gas channels. Compared with the prior art, the present invention provides a through hole penetrating two adjacent gas channels on the corrugated plate, so that in an open air flow field, air can be exchanged on both sides of the cathode plate through the through hole, disrupting the air flow of the open air flow field, thereby improving the degree of gas mixing, promoting gas diffusion in the gas diffusion layer on the cathode side, and increasing the effective area of ​​the electrode during the actual operation of the stack, significantly improving the overall performance and specific power density of the fuel cell.

Description

Technical Field

[0001] The present invention relates to the field of fuel cells, and in particular to a metal bipolar plate and an air-cooled proton exchange membrane fuel cell. Background Art

[0002] Air-cooled proton exchange membrane fuel cells are power generation devices that directly use ambient air as a coolant and oxidant to directly convert the chemical energy between the fuel and the oxidant into electrical energy. Compared with water-cooled proton exchange membrane fuel cells, air-cooled proton exchange membrane fuel cells directly use ambient air that provides the oxidant as a coolant, without the need to design a coolant flow field separately. This greatly simplifies the bipolar plate structure, and also simplifies the peripheral auxiliary equipment for the operation of the stack, such as heat dissipation equipment, thereby significantly reducing the weight of the entire power generation device.

[0003] The bipolar plate materials used in existing air-cooled proton exchange membrane fuel cells are mainly graphite and metal. The metal bipolar plate made by stamping metal sheets is lighter and stronger than the graphite bipolar plate, thereby reducing the weight of the entire power generation device and its application is becoming more and more extensive. For example, the Chinese invention patent with publication number CN102683716B discloses a bipolar plate membrane electrode assembly, which is a typical graphite material bipolar plate structure; for example, the Chinese invention patent with publication number CN101123313B discloses a metal bipolar plate for a fuel cell and a fuel cell including the metal bipolar plate, which is a typical metal material bipolar plate structure.

[0004] It can be seen from the above patent content that, whether it is a typical graphite bipolar plate or a typical metal bipolar plate, the gas flow channels on the bipolar plate are straight, resulting in a low degree of gas diffusion in the gas diffusion layer, thereby affecting the performance and specific power density of the air-cooled proton exchange membrane fuel cell. Summary of the invention

[0005] The purpose of the present invention is to provide a metal bipolar plate and an air-cooled proton exchange membrane fuel cell in order to overcome the defects of the above-mentioned prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A metal bipolar plate for an air-cooled proton exchange membrane fuel cell comprises an anode plate and a cathode plate stacked up and down, wherein the middle section of the cathode plate is a corrugated plate, each groove of the corrugated plate is used as a gas channel, and all gas channels transversely penetrate the cathode plate, and a plurality of through holes are distributed on the corrugated plate, and each through hole penetrates two adjacent gas channels.

[0008] Furthermore, the axis of the through hole and the axis of the gas channel are arranged at a certain angle.

[0009] Furthermore, the angle formed by the axis line of each through hole and the axis line of the gas channel is 45-90°.

[0010] Furthermore, a flange structure is provided at the opening of the through hole.

[0011] Furthermore, the flange structure is a brim-type plate, and the flange structure and the cathode plate are manufactured in one piece.

[0012] Furthermore, multiple horizontal rows of through holes are arranged on each side wall of the corrugated plate.

[0013] Furthermore, the corrugated plate is a metal plate with a triangular wave structure, a trapezoidal wave structure, an arc wave structure or a square wave structure.

[0014] An air-cooled proton exchange membrane fuel cell comprises a membrane electrode and the metal bipolar plate for the air-cooled proton exchange membrane fuel cell as described above, wherein the membrane electrode is packaged between two adjacent metal bipolar plates.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The present invention provides through holes penetrating two adjacent gas channels on the corrugated plate, so that in the open air flow field composed of various gas channels, the air can be exchanged on both sides of the cathode plate through the through holes, disrupting the air flow in the open air flow field, thereby improving the gas mixing degree, promoting the gas diffusion in the gas diffusion layer on the cathode side, increasing the effective area of ​​the electrode during the actual operation of the fuel cell stack, and significantly improving the overall performance and specific power density of the fuel cell.

[0017] 2. The setting of the through hole reduces the weight of the bipolar plate and helps to reduce weight.

[0018] 3. The through hole can be arranged at a certain angle with the gas channel, and a flange structure can also be provided at the opening to further improve the gas mixing degree and promote gas diffusion.

[0019] 4. The present invention has a simple structure and is easy to modify. It only requires simple improvements to the conventional structure of the existing air-cooled fuel cell, which is beneficial to reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall structure of the first embodiment.

[0021] Figure 2 It is a schematic diagram of the overall structure of embodiment 1 from another angle.

[0022] Figure 3 It is a partial enlarged view of the first embodiment.

[0023] Figure 4It is a partial enlarged view of the second embodiment.

[0024] Figure numerals: 1. cathode plate, 11. gas channel, 12. through hole, 13. flange structure, 2. anode plate, 21. fuel inlet and outlet, 22. fuel flow channel groove. DETAILED DESCRIPTION

[0025] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0026] Embodiment 1

[0027] like Figures 1 to 3 As shown, this embodiment provides a metal bipolar plate for an air-cooled proton exchange membrane fuel cell. The metal bipolar plate is a two-layer structure, the upper layer is a cathode plate 1 made of a metal sheet, and the lower layer is an anode plate 2 made of a metal sheet. Among them: the two ends of the anode plate 2 are respectively provided with a fuel inlet and outlet 21, and the middle section of the anode plate 2 is a fuel flow channel groove 22 connected to the fuel inlet and outlet 21. The two ends of the cathode plate 1 are also provided with an inlet and outlet structure (not shown in the figure), and the inlet and outlet structure of the cathode plate 1 and the fuel inlet and outlet 21 of the anode plate 2 are installed in coordination to form a sealing mechanism for ensuring the transportation and sealing of the fuel. The middle section of the cathode plate 1 is a corrugated plate. The corrugated plate can generally adopt a metal plate with a triangular wave structure, a trapezoidal corrugated structure, an arc wave structure or a square wave structure. In this embodiment, a square wave structure is adopted. Each groove of the corrugated plate forms a gas channel 11. There are also many through holes 12 distributed on the corrugated plate, and the through holes 12 run through two adjacent gas channels 11.

[0028] The through holes 12 can be arranged on the side wall in any arrangement. Usually, the through holes 12 are arranged in multiple rows horizontally on each vertical side wall of the corrugated plate. In this embodiment, a double-row layout is adopted. Because the corrugated plate has a certain thickness, each through hole 12 can also be arranged obliquely on the vertical straight side plate of the corrugated plate. Specifically, the axis of each through hole 12 and the axis of the gas channel 11 form a certain angle β. The angle β is generally 45 to 90°, and 45° is adopted in this embodiment.

[0029] The shape of the through hole 12 can be a circle, or any irregular geometric shape, such as a triangle, an ellipse, a polygon, etc. The specific shape is not limited. In this embodiment, a common circle is used.

[0030] When the metal bipolar plate is installed in the fuel cell, the upper cathode plate 1 and the membrane electrode of the fuel cell, as well as other components of the fuel cell, form an open air flow field, and the external air enters the air flow field through the gas channel 11; the lower anode plate 2 and the membrane electrode, as well as other components of the fuel cell, form a closed fuel flow field, react with the membrane electrode, and convert energy. The fuel can be, but is not limited to, high-purity hydrogen, reformed hydrogen, methanol, etc.

[0031] Through the above structure, the air entering from one side of the cathode plate 1 can flow through the through hole 12 and exchange on both sides of the corrugated plate of the cathode plate 1, disrupting the air flow of the open air flow field. Figure 2 As shown by the arrows in . This improves the gas mixing degree, promotes the gas diffusion in the cathode side gas diffusion layer on the membrane electrode, increases the effective area of ​​the membrane electrode during the actual operation of the fuel cell, and significantly improves the overall performance and specific power density of the fuel cell.

[0032] Embodiment 2

[0033] The overall structure of this embodiment is similar to that of the first embodiment and will not be repeated. The difference is that a flange structure 13 is provided at the opening of the through hole 12 to further improve the gas mixing degree and promote gas diffusion. Figure 4 As shown, the flange structure 13 in this embodiment is a brim-type plate, and the flange structure 13 and the cathode plate 1 are manufactured in one piece.

[0034] The preferred specific embodiments of the present invention are described in detail above. It should be understood that a person skilled in the art can make many modifications and changes based on the concept of the present invention without creative work. Therefore, any technical solution that can be obtained by a person skilled in the art through logical analysis, reasoning or limited experiments based on the concept of the present invention on the basis of the prior art should be within the scope of protection determined by the claims.

Claims

1. A metal bipolar plate for an air-cooled proton exchange membrane fuel cell, comprising an anode plate (2) and a cathode plate (1) stacked up and down, wherein the middle section of the cathode plate (1) is a corrugated plate, each groove of the corrugated plate is used as a gas channel (11), and all gas channels (11) transversely penetrate the cathode plate (1), characterized in that: A plurality of through holes (12) are distributed on the corrugated plate, and each through hole (12) penetrates two adjacent gas channels (11); A flange structure (13) is provided at the opening of the through hole (12); the flange structure (13) is a brim-type plate; the flange structure (13) and the cathode plate (1) are integrally formed and manufactured.

2. The metal bipolar plate for an air-cooled proton exchange membrane fuel cell according to claim 1, characterized in that: The axis of the through hole (12) and the axis of the gas channel (11) are arranged to form a certain angle.

3. The metal bipolar plate for an air-cooled proton exchange membrane fuel cell according to claim 1, characterized in that: The angle formed by the axis of each through hole (12) and the axis of the gas channel (11) is 45 to 90 degrees.

4. The metal bipolar plate for an air-cooled proton exchange membrane fuel cell according to claim 1, characterized in that: Multiple rows of through holes (12) are arranged horizontally on each side wall of the corrugated plate.

5. The metal bipolar plate for an air-cooled proton exchange membrane fuel cell according to claim 1, characterized in that: The corrugated plate is a metal plate with a triangular wave structure, a trapezoidal wave structure, an arc wave structure or a square wave structure.

6. An air-cooled proton exchange membrane fuel cell, characterized in that: The invention comprises a membrane electrode and a metal bipolar plate for an air-cooled proton exchange membrane fuel cell as claimed in any one of claims 1 to 5, wherein the membrane electrode is packaged between two adjacent metal bipolar plates.

Images