Fuel cell stack and fuel cell

Abstract

The invention provides a fuel cell stack and a fuel cell. The fuel cell stack comprises: a collector plate; a bipolar plate assembly; and a runner plate. According to the fuel cell stack and the fuel cell provided by the invention, the second side surface of the runner plate is attached and matched with the bipolar plate assembly, so that the situation that in the prior art, a bipolar plate is in direct contact with a collector plate, and fuel flows in a runner between the bipolar plate and the collector plate and cannot be utilized is avoided; the flow channel plates are arranged, so that the distance between the bipolar plate assemblies and the collector plates can be increased, the uniformity degree when the collector plates are fed into the adjacent bipolar plate assemblies can be ensured, fluid in the bipolar plate assemblies can be ensured to smoothly flow into the collector plates, and the efficiency of the fuel cell is improved. Therefore, the working efficiency of the bipolar plate assembly close to the collector plate is improved, and the working efficiency and the fuel utilization rate of the fuel cell are further improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fuel cells, in particular to a fuel cell stack and a fuel cell. Background Art

[0002] A proton exchange membrane fuel cell is a device that converts the chemical energy of fuel directly into electrical energy through an electrochemical reaction. Its basic working principle is that hydrogen and air reach the anode and cathode of the fuel cell respectively under the action of the hydrogen supply system and the air supply system. Hydrogen generates hydrogen ions and electrons under the catalytic action of the catalyst. The electrons reach the cathode through an external circuit to generate electrical energy, and the hydrogen ions reach the cathode through the proton exchange membrane. At the same time, the oxygen in the air reacts with the hydrogen ions to generate water under the action of the catalyst. From the perspective of energy conservation, the utilization rate of the fuel determines the efficiency of the fuel cell to a certain extent.

[0003] A fuel cell stack is a fuel cell stack structure, which is mainly composed of upper and lower end plates, upper and lower insulating plates, positive and negative current collectors and a single cell stack. At present, the most common stack assembly process is to stack the bipolar plate, membrane electrode, and bipolar plate in sequence between the installed upper end plate, insulating plate, current collector, and lower end plate to assemble a fuel cell stack. During the operation of this structure, the fuel in the flow channel cavity of the anode plate directly contacted by the positive current collector and the cathode current collector directly contacted by the negative current collector does not participate in the electrochemical reaction but is directly discharged with the exhaust gas, resulting in fuel waste, which reduces the working efficiency and fuel utilization rate of the fuel cell to a certain extent. Summary of the invention

[0004] In order to solve the technical problem in the prior art that part of the fuel flows through the flow channel between the collecting plate and the bipolar plate, causing the efficiency of the fuel cell to be reduced, a fuel cell stack and a fuel cell are provided that utilize a flow channel plate to avoid fuel leakage and ensure uniform fuel distribution to ensure working efficiency and fuel utilization.

[0005] A fuel cell stack, comprising:

[0006] Collector plate;

[0007] A bipolar plate assembly, wherein the bipolar plate assembly is disposed on one side of the current collecting plate;

[0008] A flow channel plate, wherein the flow channel plate is arranged between the current collecting plate and the bipolar plate assembly, the flow channel plate has a first side surface and a second side surface opposite to each other, the first side surface is fitted with the current collecting plate, the second side surface is fitted with the bipolar plate assembly, and a flow channel is arranged on the second side surface.

[0009] The current collecting plate includes an upper current collecting plate and a lower current collecting plate, the flow channel plate includes an upper flow channel plate and a lower flow channel plate, the bipolar plate assembly is arranged between the upper current collecting plate and the lower current collecting plate, and the upper flow channel plate is arranged between the upper current collecting plate and the bipolar plate assembly, and the lower flow channel plate is arranged between the lower current collecting plate and the bipolar plate assembly.

[0010] The number of the bipolar plate assemblies is at least two, all of the bipolar plate assemblies are arranged in parallel along the direction from the upper current collecting plate to the lower current collecting plate, and the upper flow plate is located between the upper current collecting plate and the bipolar plate assembly adjacent to the upper current collecting plate, and the lower flow plate is located between the lower current collecting plate and the bipolar plate assembly adjacent to the lower current collecting plate.

[0011] The bipolar plate assembly is provided with an air inlet channel and an air outlet channel. In two adjacent bipolar plate assemblies, the two air inlet channels are interconnected, and the two air outlet channels are interconnected.

[0012] The bipolar plate assembly comprises an anode plate, a membrane electrode and a cathode plate which are arranged in sequence. In two adjacent bipolar plate assemblies, the anode plate of one bipolar plate assembly is welded to the cathode plate of the other bipolar plate assembly.

[0013] The bipolar plate assembly includes an anode plate, a membrane electrode and a cathode plate arranged in sequence, and the upper flow plate is welded to the anode plate in the adjacent bipolar plate assembly; and / or the lower flow plate is welded to the cathode plate in the adjacent bipolar plate assembly.

[0014] The fuel cell stack further includes a first seal, an air inlet and an air outlet are provided on the anode plate, the first seal is provided between the anode plate and the membrane electrode, and the first seal surrounds the air inlet and the air outlet respectively.

[0015] The fuel cell stack also includes a second seal, the cathode plate is provided with an air inlet and an air outlet, the second seal is arranged between the cathode plate and the membrane electrode, and the cathode plate, the second seal and the membrane electrode together form a reaction channel, and the air inlet and the air outlet are both connected to the reaction channel.

[0016] The fuel cell stack further includes an end plate and an insulating plate, wherein the end plate is disposed on the current collecting plate via the insulating plate.

[0017] A fuel cell comprises the above-mentioned fuel cell stack.

[0018] The fuel cell stack and fuel cell provided by the present invention, by arranging a flow channel plate between the bipolar plate and the current collecting plate, utilizes the fit between the second side of the flow channel plate and the bipolar plate assembly to ensure that the fuel can flow on the side of the bipolar plate to ensure the normal operation of the bipolar plate assembly, and at the same time, no flow channel is arranged on the first side of the flow channel plate, that is, the first side of the flow channel plate is a smooth and flat plane, which can be sealed and fitted with the current collecting plate so that the fuel cannot flow there, thereby avoiding the direct contact between the bipolar plate and the current collecting plate in the prior art, and the fuel flow in the fuel flow channel between the bipolar plate and the current collecting plate cannot be utilized, thereby improving the efficiency and fuel utilization rate of the fuel cell, and by arranging the flow channel plate, the distance between the bipolar plate assembly and the current collecting plate can be increased, ensuring the uniformity when the current collecting plate is fed into the adjacent bipolar plate assembly, and also ensuring that the fluid in the bipolar plate assembly can smoothly flow into the current collecting plate, thereby improving the working efficiency of the bipolar plate assembly close to the current collecting plate, and further improving the working efficiency and fuel utilization rate of the fuel cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic diagram of the structure of a fuel cell stack provided by an embodiment of the present invention;

[0020] Figure 2 A schematic structural diagram of a first side surface of a flow channel plate provided in an embodiment of the present invention;

[0021] Figure 3 A schematic structural diagram of a second side surface of an upper flow channel plate provided in an embodiment of the present invention;

[0022] Figure 4 A schematic structural diagram of a second side surface of a downflow channel plate provided in an embodiment of the present invention;

[0023] Figure 5 A schematic diagram of the structure of an anode plate provided in an embodiment of the present invention;

[0024] Figure 6 A schematic diagram of the structure of a cathode plate provided in an embodiment of the present invention;

[0025] In the figure:

[0026] 1. Upper current collecting plate; 2. Lower current collecting plate; 3. Upper flow channel plate; 4. Lower flow channel plate; 52. Second sealing member; 11. Air inlet; 12. Air outlet; 51. First sealing member; 13. Reaction channel; 6. Anode plate; 7. Membrane electrode; 8. Cathode plate; 9. End plate; 10. Insulating plate. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0030] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0031] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0032] A fuel cell stack is a fuel cell stack structure, which is mainly composed of upper and lower end plates, upper and lower insulating plates, positive and negative current collectors and a single cell stack. At present, the most common stack assembly process is to stack the bipolar plate, membrane electrode, and bipolar plate in sequence between the installed upper end plate, insulating plate, current collector, and lower end plate to assemble a fuel cell stack. During the operation of this structure, the fuel in the flow channel cavity of the anode plate directly contacted by the positive current collector and the cathode current collector directly contacted by the negative current collector does not participate in the electrochemical reaction but is directly discharged with the exhaust gas, resulting in fuel waste, which reduces the working efficiency and fuel utilization rate of the fuel cell to a certain extent.

[0033] To this end, the present application provides a Figures 1 to 6 A fuel cell stack shown includes: a current collecting plate; a bipolar plate assembly, wherein the bipolar plate assembly is arranged on one side of the current collecting plate; a flow channel plate, wherein the flow channel plate is arranged between the current collecting plate and the bipolar plate assembly, and the flow channel plate has a first side surface and a second side surface opposite to each other, wherein the first side surface is fitted with the current collecting plate, and the second side surface is fitted with the bipolar plate assembly, and a flow channel is arranged on the second side surface.

[0034] By setting a flow channel plate between the bipolar plate and the current collecting plate, and utilizing the fit between the second side of the flow channel plate and the bipolar plate assembly, it is ensured that the fuel can flow on the side of the bipolar plate to ensure the normal operation of the bipolar plate assembly. At the same time, no flow channel is set on the first side of the flow channel plate, that is, the first side of the flow channel plate is a smooth and flat plane, which can be sealed and fitted with the current collecting plate to prevent the fuel from flowing there. This avoids the situation in the prior art where the bipolar plate directly contacts the current collecting plate and the fuel flow in the existing fuel flow channel between the bipolar plate and the current collecting plate cannot be utilized, thereby improving the efficiency and fuel utilization of the fuel cell. In addition, by setting the flow channel plate, the distance between the bipolar plate assembly and the current collecting plate can be increased, ensuring the uniformity when the current collecting plate is fed into the adjacent bipolar plate assembly, and also ensuring that the fluid in the bipolar plate assembly can smoothly flow into the current collecting plate, thereby improving the working efficiency of the bipolar plate assembly close to the current collecting plate, further improving the working efficiency and fuel utilization of the fuel cell.

[0035] As an embodiment, the current collecting plate includes an upper current collecting plate 1 and a lower current collecting plate 2, the flow channel plate includes an upper flow channel plate 3 and a lower flow channel plate 4, the bipolar plate assembly is arranged between the upper current collecting plate 1 and the lower current collecting plate 2, and the upper flow channel plate 3 is arranged between the upper current collecting plate 1 and the bipolar plate assembly, and the lower flow channel plate 4 is arranged between the lower current collecting plate 2 and the bipolar plate assembly. The upper current collecting plate 1 can transport the fuel to the bipolar plate assembly, and due to the arrangement of the upper flow channel plate 3, the flow channel on the second side of the upper flow channel plate 3 can transport the fuel to the bipolar plate assembly to participate in the reaction, and the first side of the upper flow channel plate 3 is arranged in close contact with the upper current collecting plate 1, and the fuel cannot flow through the position between the upper flow channel plate 3 and the upper current collecting plate 1, so that all fuels need to flow to the bipolar plate assembly to participate in the reaction, thereby achieving the purpose of ensuring the working efficiency and fuel utilization rate of the fuel cell.

[0036] Similarly, the lower collecting plate 2 can transport the fuel to the bipolar plate assembly, and due to the setting of the lower flow plate 4, the flow channel on the second side of the lower flow plate 4 can transport the fuel to the bipolar plate assembly to participate in the reaction, and the first side of the lower flow plate 4 is fitted with the lower collecting plate 2, and the fuel cannot flow through the position between the lower flow plate 4 and the lower collecting plate 2, so that all the fuel needs to flow to the bipolar plate assembly to participate in the reaction, thereby achieving the purpose of ensuring the working efficiency of the fuel cell and the fuel utilization rate.

[0037] The number of the bipolar plate assemblies is at least two, and all the bipolar plate assemblies are arranged in parallel along the direction from the upper current collecting plate 1 to the lower current collecting plate 2, and the upper flow plate 3 is located between the upper current collecting plate 1 and the bipolar plate assembly adjacent to the upper current collecting plate 1, and the lower flow plate 4 is located between the lower current collecting plate 2 and the bipolar plate assembly adjacent to the lower current collecting plate 2. By arranging multiple bipolar plate assemblies, the energy efficiency of the fuel cell can be effectively improved, and the utilization efficiency of the fuel can also be improved.

[0038] Since there are multiple bipolar plate assemblies, in order to allow the fuel to flow to all bipolar plate assemblies to participate in the reaction, the bipolar plate assemblies are provided with an inlet channel and an outlet channel. In two adjacent bipolar plate assemblies, the two inlet channels are interconnected, and the two outlet channels are interconnected. The fuel can flow through all bipolar plate assemblies in sequence along the inlet channel. In the process of the fuel flowing through the bipolar plate assemblies, part of the fuel will enter the bipolar plate assemblies to participate in the reaction, and the remaining fuel can enter the next bipolar plate assembly. The fluid entering the bipolar plate assembly can be discharged through the outlet channel after the reaction is completed, thereby completing the reaction process of the fuel and ensuring the working reliability of all bipolar plate assemblies.

[0039] The bipolar plate assembly includes an anode plate 6, a membrane electrode 7 and a cathode plate 8 arranged in sequence. In two adjacent bipolar plate assemblies, the anode plate 6 of one bipolar plate assembly is welded to the cathode plate 8 of the other bipolar plate assembly, which is convenient for setting the two adjacent bipolar plate assemblies. Preferably, the anode plate 6 of one bipolar plate assembly is welded to the cathode plate 8 of the other bipolar plate assembly, and the sealing fit of the anode plate 6 and the cathode plate 8 is achieved by welding. When installing the fuel cell stack, the membrane electrode 7 is arranged between the welded anode plate 6 and the cathode plate 8, and then the structure of the stacked fuel cell stack is compressed. At this time, the membrane electrode 7 and the anode plate 6 and the cathode plate 8 adjacent to the membrane electrode 7 together constitute a bipolar plate assembly to realize the production of the fuel cell stack. Preferably, the anode plate 6 and the cathode plate 8 are both metal plates.

[0040] Specifically, the bipolar plate assembly includes an anode plate 6, a membrane electrode 7 and a cathode plate 8 arranged in sequence, and the upper flow plate 3 is welded with the anode plate 6 in the adjacent bipolar plate assembly to achieve a sealed fit between the upper flow plate 3 and the anode plate 6, and the first fuel (such as hydrogen) of the fuel cell stack can pass through the upper flow plate 3 and the anode plate 6 in sequence and reach the cathode plate 8, and will not flow between the anode plate 6 and the upper flow plate 3, thereby further avoiding the problem of fuel not participating in the reaction, improving the working efficiency and fuel utilization of the fuel cell, and ensuring the working reliability of the bipolar plate assembly and the fuel cell stack. Preferably, the upper flow plate 3 is a metal plate.

[0041] Similarly, the bipolar plate assembly includes an anode plate 6, a membrane electrode 7 and a cathode plate 8 which are arranged in sequence. The downflow plate 4 is welded to the cathode plate 8 in the adjacent bipolar plate assembly to achieve a sealed fit between the downflow plate 4 and the cathode plate 8. At this time, the first fuel (such as hydrogen) delivered to the cathode plate 8 will not leak between the downflow plate 4 and the cathode plate 8, thereby further avoiding the problem of the fuel not participating in the reaction, improving the working efficiency and fuel utilization of the fuel cell, and ensuring the working reliability of the bipolar plate assembly and the fuel cell stack. Preferably, the downflow plate 4 is a metal plate.

[0042] The fuel cell stack further includes a first seal 51. The anode plate 6 is provided with an air inlet 11 and an air outlet 12. The first seal 51 is provided between the anode plate 6 and the membrane electrode 7, and the first seal 51 surrounds the air inlet 11 and the air outlet 12 respectively. The first seal 51 surrounds the air inlet 11 to form a sealing ring around the air inlet 11, so that the first fuel (such as hydrogen) flowing through the anode plate 6 can only continue to flow through the air inlet 11 and the first seal 51 and pass through the membrane electrode 7, and will not flow into the space between the anode plate 6 and the membrane electrode 7, while the second fuel (such as oxygen or air) can flow from the periphery of the first seal 51 into the space between the anode plate 6 and the membrane electrode 7 to participate in the reaction. At this time, the first seal 51 can separate the two fuels, thereby ensuring the working reliability of the fuel cell.

[0043] The fuel cell stack also includes a second seal 52. The cathode plate 8 is provided with an air inlet 11 and an air outlet 12. The second seal 52 is provided between the cathode plate 8 and the membrane electrode 7. The cathode plate 8, the second seal 52 and the membrane electrode 7 together form a reaction channel 13. The air inlet 11 and the air outlet 12 are both connected to the reaction channel 13. By utilizing the sealing effect of the second seal 52, part of the fuel from the air inlet 11 can be introduced into the reaction channel 13 to participate in the reaction, while the second fuel entering from the lower collector plate 4 can only flow to the periphery of the second seal 52 and cannot enter the reaction channel 13. At this time, the second seal 52 can separate the two fuels, thereby ensuring the working reliability of the fuel cell.

[0044] During the operation of the fuel cell stack, only the fuel in the flow channels of the anode plate 6 and the cathode plate 8 that are in contact with the membrane electrode 7 can react with the catalyst on the membrane electrode 7 to generate protons and electrons, and convert chemical energy into electrical energy. The flow channels through which the fuel flows can all participate in the electrochemical reaction to generate electrical energy, thereby improving the utilization rate of the fuel, solving the problem in the prior art of the fuel cell stack that the fuel flowing through the flow channels that are in direct contact with the collector plate does not participate in the chemical reaction and is directly discharged as exhaust gas, thus wasting fuel, thereby improving the efficiency of the fuel cell stack to a certain extent.

[0045] The fuel cell stack further includes an end plate 9 and an insulating plate 10, and the end plate 9 is disposed on the current collecting plate through the insulating plate 10. Through the arrangement of the end plate 9, the upper current collecting plate 1, the upper flow channel plate 3, all bipolar plate assemblies, the lower flow channel plate 4 and the lower current collecting plate 2 are integrated into a whole, thereby achieving the structural reliability of the fuel cell stack.

[0046] A fuel cell comprises the above-mentioned fuel cell stack, wherein the first fuel and the second fuel of the fuel cell are air and hydrogen respectively, and a cavity (including the reaction channel 13) is formed on the surface of the bipolar plate as a reactor for chemical reaction, providing a place for storage and chemical reaction for hydrogen and air.

[0047] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A fuel cell stack, characterized in that: include: Collector plate; A bipolar plate assembly, wherein the bipolar plate assembly is disposed on one side of the current collecting plate; A flow channel plate, wherein the flow channel plate is arranged between the current collecting plate and the bipolar plate assembly, the flow channel plate has a first side surface and a second side surface opposite to each other, the first side surface is fitted with the current collecting plate, the second side surface is fitted with the bipolar plate assembly, and a flow channel is arranged on the second side surface.

2. The fuel cell stack according to claim 1, characterized in that: The current collecting plate comprises an upper current collecting plate (1) and a lower current collecting plate (2); the flow channel plate comprises an upper flow channel plate (3) and a lower flow channel plate (4); the bipolar plate assembly is arranged between the upper current collecting plate (1) and the lower current collecting plate (2); the upper flow channel plate (3) is arranged between the upper current collecting plate (1) and the bipolar plate assembly; and the lower flow channel plate (4) is arranged between the lower current collecting plate (2) and the bipolar plate assembly.

3. The fuel cell stack according to claim 2, characterized in that: The number of the bipolar plate assemblies is at least two, and all the bipolar plate assemblies are arranged in parallel along the direction from the upper current collecting plate (1) to the lower current collecting plate (2), and the upper flow plate (3) is located between the upper current collecting plate (1) and the bipolar plate assembly adjacent to the upper current collecting plate (1), and the lower flow plate (4) is located between the lower current collecting plate (2) and the bipolar plate assembly adjacent to the lower current collecting plate (2).

4. The fuel cell stack according to claim 3, characterized in that: The bipolar plate assembly is provided with an air inlet channel and an air outlet channel. In two adjacent bipolar plate assemblies, the two air inlet channels are interconnected, and the two air outlet channels are interconnected.

5. The fuel cell stack according to claim 3, characterized in that: The bipolar plate assembly comprises an anode plate (6), a membrane electrode (7) and a cathode plate (8) which are arranged in sequence. In two adjacent bipolar plate assemblies, the anode plate (6) of one bipolar plate assembly is welded to the cathode plate (8) of the other bipolar plate assembly.

6. The fuel cell stack according to claim 2, characterized in that: The bipolar plate assembly comprises an anode plate (6), a membrane electrode (7) and a cathode plate (8) which are arranged in sequence, wherein the upper flow channel plate (3) is welded to the anode plate (6) in the adjacent bipolar plate assembly; and / or the lower flow channel plate (4) is welded to the cathode plate (8) in the adjacent bipolar plate assembly.

7. The fuel cell stack according to claim 5 or 6, characterized in that: The fuel cell stack further comprises a first seal (51), the anode plate (6) is provided with an air inlet (11) and an air outlet (12), the first seal (51) is arranged between the anode plate (6) and the membrane electrode (7), and the first seal (51) surrounds the air inlet (11) and the air outlet (12), respectively.

8. The fuel cell stack according to claim 5 or 6, characterized in that: The fuel cell stack further comprises a second sealing member (52); an air inlet (11) and an air outlet (12) are provided on the cathode plate (8); the second sealing member (52) is arranged between the cathode plate (8) and the membrane electrode (7); and the cathode plate (8), the second sealing member (52) and the membrane electrode (7) together form a reaction channel (13); and the air inlet (11) and the air outlet (12) are both connected to the reaction channel (13).

9. The fuel cell stack according to claim 1, characterized in that: The fuel cell stack further comprises an end plate (9) and an insulating plate (10), wherein the end plate (9) is arranged on the current collecting plate via the insulating plate (10).

10. A fuel cell, characterized in that: A fuel cell stack comprising the fuel cell stack described in any one of claims 1 to 9.

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