Fuel cell and fuel cell stack including the same

Abstract

The present invention discloses a fuel cell cell and a fuel cell stack including the same. The fuel cell cell according to the present invention includes a membrane electrode assembly; an anode plate and a cathode plate are respectively located on both sides of the membrane electrode assembly; an anode heat sink is located on one side of the anode plate, and the anode plate is between the anode heat sink and the membrane electrode assembly; a cathode heat sink is located on one side of the cathode plate, and the cathode plate is between the cathode heat sink and the membrane electrode assembly, wherein the fuel cell cell is a cathode closed type; a heat sink is provided on the surface of the anode heat sink facing away from the anode plate, and the heat sink is used for direct contact with the cathode heat sink of an adjacent fuel cell cell; or a heat sink is provided on the surface of the cathode heat sink facing away from the cathode plate, and the heat sink is used for direct contact with the anode heat sink of an adjacent fuel cell cell. The fuel cell cell according to the present invention and the fuel cell stack including the same have high power, long life, good reliability, and good electrical performance.

Description

Technical Field

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

[0002] A fuel cell is a power generation device that generates electricity through an electrochemical reaction between a fuel such as methanol or hydrogen and an oxidizing gas in the catalyst layer of a membrane electrode assembly. Fuel cells are a clean energy source that can provide clean electricity, and therefore have been increasingly widely used.

[0003] In recent years, with the increasing maturity of drone technology and the gradual opening of low-altitude economic airspace control, the prototype of a huge low-altitude economic industrial chain in China has begun to emerge, and the low-altitude economy has become a new economic "growth pole" that various places are competing for. As a flying platform, the value of an aircraft depends on its flight time and load, and the energy density of hydrogen fuel cells is three times that of lithium batteries. It can provide longer flight time for aircraft such as manned and cargo, eVTOL (Electric Vertical Takeoff and Landing), and flying cars. Many leading companies in aircraft such as eVTOL and flying cars are looking for hydrogen energy solutions everywhere, and there is an urgent need to improve the power and power density of fuel cell air-cooled stacks. The existing fuel cell air-cooled stacks on the market mostly use graphite plate stacks, and the cathode side mostly uses an open setting. A large amount of air reacts with hydrogen as a reaction gas on the one hand, and also acts as a cooling gas to dissipate heat from the stack. In order to ensure sufficient air-cooling and heat dissipation, the air volume must be large enough, but a large amount of air can easily cause the membrane electrode to be blown dry, and the membrane electrode is constantly switching between dry and wet, which accelerates the mechanical aging of the proton membrane. More impurities in the air will also enter the cathode flow field and directly contact the membrane electrode assembly. This working mode of the open air-cooled stack affects the service life of the proton exchange membrane. The service life of the open air-cooled stack is generally only maintained at 300-500 hours; at the same time, it reduces the performance of the fuel cell stack. The open air-cooled stack is generally only a few hundred or a few kilowatts, and it is difficult to exceed 5kW.

[0004] Therefore, it is hoped that there will be a new fuel cell and a fuel cell stack including the same that can overcome the above problems. Summary of the invention

[0005] In view of the above problems, the object of the present invention is to provide a fuel cell single cell and a fuel cell stack including the same, especially a high-power and long-life metal-graphite composite air-cooled single cell and stack, so as to increase the power, extend the life, enhance the reliability and improve the electrical performance of the single cell and the stack.

[0006] According to one aspect of the present invention, there is provided a fuel cell unit cell, comprising:

[0007] Membrane electrode assembly;

[0008] an anode plate and a cathode plate, wherein the anode plate and the cathode plate are respectively located on two sides of the membrane electrode assembly;

[0009] an anode heat sink, the anode heat sink being located on one side of the anode plate, the anode plate being interposed between the anode heat sink and the membrane electrode assembly; and

[0010] a cathode cooling plate, the cathode cooling plate being located on one side of the cathode plate, the cathode plate being interposed between the cathode cooling plate and the membrane electrode assembly,

[0011] Wherein, the fuel cell single cell is of cathode-sealed type;

[0012] The surface of the anode heat sink facing away from the anode plate is provided with heat dissipation teeth, and the heat dissipation teeth are used for direct contact with the cathode heat sink of the adjacent fuel cell cell; or

[0013] The cathode heat dissipation plate is provided with heat dissipation teeth on a surface of a side away from the cathode plate, and the heat dissipation teeth are used for direct contact with the anode heat dissipation plate of the adjacent fuel cell cell.

[0014] Optionally, a heat dissipation tooth is provided on the surface of the anode heat dissipation plate on the side facing away from the anode plate, and when the heat dissipation tooth is used for direct contact with the cathode heat dissipation plate of an adjacent fuel cell cell, the surface of the anode heat dissipation plate close to the anode plate is a plane; the surface of the cathode heat dissipation plate on the side facing away from the cathode plate is a plane, and a groove is provided on the surface of the cathode heat dissipation plate close to the cathode plate; or

[0015] Heat dissipation teeth are arranged on the surface of the cathode heat dissipation plate facing away from the cathode plate. When the heat dissipation teeth are used for direct contact with the anode heat dissipation plate of an adjacent fuel cell cell, the surface of the cathode heat dissipation plate close to the cathode plate is a plane; the surface of the anode heat dissipation plate facing away from the anode plate is a plane, and grooves are arranged on the surface of the anode heat dissipation plate close to the anode plate.

[0016] Optionally, the fuel cell unit cell further comprises:

[0017] A first seal is provided between the anode cooling plate and the cathode cooling plate and is used for sealing the membrane electrode assembly.

[0018] Optionally, the fuel cell unit cell further comprises:

[0019] A second seal is located between the anode heat dissipation plate and the cathode heat dissipation plate of an adjacent fuel cell unit cell and / or between the cathode heat dissipation plate and the anode heat dissipation plate of an adjacent fuel cell unit cell.

[0020] Optionally, the cathode plate is a graphite plate, and the anode plate is a metal plate;

[0021] The cathode heat sink and / or the anode heat sink are metal plates, and the metal plates include at least one selected from a silver plate, a copper plate, an aluminum plate, and a stainless steel plate.

[0022] Optionally, the cathode plate is located in a closed cavity, and the fuel cell cell further comprises:

[0023] A gas source is communicated with the closed cavity to provide reaction gas to the cathode plate.

[0024] Optionally, the heat dissipation teeth are strip-shaped, and the length direction of the heat dissipation teeth is the same as the width direction of the cathode heat dissipation plate and / or the anode heat dissipation plate.

[0025] Optionally, the width of the heat dissipation teeth is between 1 mm and 5 mm, and the height of the heat dissipation teeth is between 1 mm and 5 mm.

[0026] Optionally, a heat dissipation channel is formed between adjacent heat dissipation teeth, and a width of the heat dissipation channel is between 1 mm and 8 mm.

[0027] According to another aspect of the present invention, there is provided a fuel cell stack, comprising:

[0028] mounting bracket; and

[0029] The fuel cell unit cell as described above is arranged on the mounting frame.

[0030] The fuel cell cell and the fuel cell stack including the same provided by the present invention are of cathode-closed type, and heat dissipation teeth are provided on the surface of the heat dissipation plate on the side away from the electrode plate. The heat dissipation teeth are also used for direct contact with the heat dissipation plate of the adjacent fuel cell cell. While ensuring sufficient heat dissipation of the fuel cell, they can also play a good sealing role and reduce the ohmic internal resistance between the cells, thereby improving the performance of the fuel cell.

[0031] Furthermore, the heat dissipation teeth (heat dissipation channels) on the heat dissipation plate adopt a specific size ratio, ensuring that the battery stack has good heat dissipation, electronic conductivity and sealing performance.

[0032] Furthermore, the heat dissipation tooth parameters of the heat dissipation plate made of graphite are limited to a certain range, which not only ensures good contact with the battery plane and reduces the contact internal resistance, but also ensures smooth heat dissipation of the heat dissipation channel.

[0033] Furthermore, the cathode is sealed, a gas source is used to provide reaction gas to the cathode, and the cathode is humidified, which can improve the electrical performance of the single cell / stack, increase power, extend life, and enhance reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The above and other objects, features and advantages of the present invention will become more apparent through the following description of the embodiments of the present invention with reference to the accompanying drawings, in which:

[0035] Figure 1 A schematic diagram of the structure of a fuel cell cell according to an embodiment of the present invention is shown;

[0036] Figure 2 A schematic structural diagram of an anode heat sink according to an embodiment of the present invention is shown;

[0037] Figure 3 A schematic diagram of packaging a fuel cell stack according to an embodiment of the present invention is shown;

[0038] Figure 4 A schematic diagram showing contact surfaces of adjacent cells in a fuel cell stack according to an embodiment of the present invention is shown;

[0039] Figure 5 A schematic diagram of the three-dimensional structure of a fuel cell stack according to an embodiment of the present invention is shown;

[0040] Figure 6 A schematic diagram of a fuel cell stack according to an embodiment of the present invention is shown;

[0041] Figure 7 A performance data comparison chart of a fuel cell stack according to an embodiment of the present invention is shown in the non-pressurized and non-humidified state and the pressurized and humidified state. DETAILED DESCRIPTION

[0042] Various embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. In each of the accompanying drawings, identical elements are represented by identical or similar reference numerals. For the sake of clarity, the various parts in the accompanying drawings are not drawn to scale. In addition, some well-known parts may not be shown in the drawings.

[0043] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. Many specific details of the present invention, such as the structure, materials, dimensions, processing technology and techniques of the components are described below to provide a clearer understanding of the present invention. However, as those skilled in the art will appreciate, the present invention may be implemented without following these specific details.

[0044] It should be understood that when describing the structure of a component, when a layer or a region is referred to as being "on" or "over" another layer or another region, it may mean that it is directly on the other layer or another region, or that other layers or regions are included between it and the other layer or another region. Moreover, if the component is turned over, the layer or a region will be "below" or "beneath" another layer or another region.

[0045] Figure 1 FIG. 2 shows a schematic diagram of the structure of a fuel cell cell according to an embodiment of the present invention. Figure 1 As shown, a fuel cell 10 according to an embodiment of the present invention includes a membrane electrode assembly 100 , an anode plate 200 , a cathode plate 300 , an anode heat dissipation plate 400 , and a cathode heat dissipation plate 500 .

[0046] Specifically, the membrane electrode assembly (MEA) 100 is where the electrochemical reaction of the oxidizing gas and the reducing gas is carried out in the fuel cell. The membrane electrode assembly 100 includes, for example, a three-in-one proton exchange membrane (CCM) and a gas diffusion layer (GDL). The three-in-one proton exchange membrane plays a role in transferring protons, so that protons can be transferred between the anode and the cathode to complete the electrochemical reaction.

[0047] The anode plate 200 and the cathode plate 300 are respectively located on both sides of the membrane electrode assembly 100. The function of the anode plate 200 is to receive fuel and promote hydrogen oxidation reaction or methanol oxidation reaction to produce electrons and positive ions. There is also a catalyst (usually platinum or other precious metals) on the anode plate 200 to accelerate the fuel oxidation reaction. The function of the cathode plate 300 is to receive oxygen and promote oxygen reduction reaction, usually oxygen reduction to water. In this process, the catalyst (usually platinum) on the cathode plate 300 plays a catalytic role to accelerate the oxygen reduction reaction. Through the action of the cathode plate 300 and the anode plate 200, the fuel cell can convert chemical energy into electrical energy. Optionally, the membrane electrode assembly 100, the anode plate 200 and the cathode plate 300 constitute a basic unit of a single cell.

[0048] The anode heat sink 400 is located on one side of the anode plate 200, and the anode plate 200 is between the anode heat sink 400 and the membrane electrode assembly 100. The anode heat sink 400 is, for example, in direct contact with the anode plate 200 for heat dissipation at the anode end. Optionally, the anode heat sink 400 and the anode plate 200 are integrally formed.

[0049] The cathode heat sink 500 is located on one side of the cathode plate 300, and the cathode plate 300 is between the cathode heat sink 500 and the membrane electrode assembly 100. The cathode heat sink 500 is, for example, in direct contact with the cathode plate 300 for heat dissipation at the cathode end. Optionally, the cathode heat sink 500 and the cathode plate 200 are integrally formed.

[0050] The fuel cell is a cathode-enclosed type, that is, the cathode gas chamber is isolated from the external environment. In a cathode-enclosed fuel cell, oxygen enters the cell through a closed gas channel and reacts with the fuel (such as hydrogen or methanol) on the anode to produce electricity and water. Optionally, the fuel cell is a proton exchange membrane fuel cell (PEMFC).

[0051] like Figure 1 As shown, the surface of the anode heat sink 400 facing away from the anode plate 200 is provided with heat dissipation teeth. The heat dissipation teeth are used for direct contact with the cathode heat sink of the adjacent fuel cell. Further, the surface of the anode heat sink 400 close to the anode plate 200 is a plane. The surface of the cathode heat sink 500 facing away from the cathode plate 300 is a plane, and the surface of the cathode heat sink 500 close to the cathode plate 300 is provided with grooves.

[0052] Figure 1 Only one solution of the present application is shown, and the solution of the present application is not limited thereto. Optionally, a heat dissipation tooth is provided on the surface of the cathode heat dissipation plate on the side facing away from the cathode plate, and the heat dissipation tooth is used for direct contact with the anode heat dissipation plate of the adjacent fuel cell cell. Furthermore, the surface of the cathode heat dissipation plate close to the cathode plate is a plane; the surface of the anode heat dissipation plate on the side facing away from the anode plate is a plane, and a groove is provided on the surface of the anode heat dissipation plate close to the anode plate.

[0053] Optionally, the cathode plate 300 is a graphite plate, and the anode plate 200 is a metal plate. Optionally, the cathode heat sink 500 and / or the anode heat sink 400 is a metal plate, and the metal plate includes at least one selected from silver plate, copper plate, aluminum plate and stainless steel plate.

[0054] Figure 2 FIG. 2 shows a schematic diagram of the structure of an anode heat sink according to an embodiment of the present invention. Figure 2 As shown, the anode heat sink 400 is provided with heat dissipation teeth 410, and a heat dissipation channel 420 is formed between adjacent heat dissipation teeth 410. The front view shows the side with heat dissipation teeth, and the rear view shows the side without heat dissipation teeth.

[0055] like Figure 2 As shown, the heat dissipation teeth 410 are strip-shaped. The length direction of the heat dissipation teeth is the same as the width direction of the anode heat dissipation plate 200. The side without the heat dissipation teeth is a smooth surface (flat surface).

[0056] Optionally, the width of the heat dissipation teeth 410 is between 1 mm and 5 mm, preferably between 1 mm and 3 mm. The height of the heat dissipation teeth 410 is between 1 mm and 5 mm, preferably between 2 mm and 4 mm.

[0057] Optionally, a heat dissipation channel 420 is formed between adjacent heat dissipation teeth 410. The width of the heat dissipation channel 420 is between 1 mm and 8 mm, preferably between 2 mm and 5 mm.

[0058] certainly, Figure 2 The structure of the heat dissipation teeth is shown by taking the anode heat dissipation plate as an example. The heat dissipation plate shown in the figure may also be a cathode heat dissipation plate.

[0059] Figure 3 FIG. 1 shows a schematic diagram of a fuel cell stack package according to an embodiment of the present invention. Figure 3 As shown, the figure shows three fuel cell cells stacked from top to bottom. The first seal 610 is disposed between the anode heat sink 400 and the cathode heat sink 500 for sealing the membrane electrode assembly 100. Optionally, at least a portion of the first seal 610 is located between the cathode plate and the anode plate (not shown in the figure). The first seal 610 is, for example, a sealant.

[0060] The second seal 620 is located between the anode heat sink 400 and the cathode heat sink 500 of the adjacent fuel cell. The second seal 620 may also be located between the cathode heat sink 500 and the anode heat sink 400 of the adjacent fuel cell. The second seal 620 is, for example, sealant.

[0061] In an optional embodiment of the present invention, the fuel cell is a cathode-enclosed type. The cathode plate is located in the enclosed cavity. The fuel cell further comprises a gas source. The gas source is connected to the enclosed cavity to provide a reaction gas to the cathode plate. Optionally, if there is a seal or other component blocking the path of the gas source to provide the reaction gas to the cathode plate, a gas guide channel can be started on the seal or other component.

[0062] In a specific embodiment of the present invention, a long-life, high-power cathode-enclosed metal-graphite composite air-cooled single cell and stack are provided. The stack adopts a single cell mode, and the fuel cell single cell includes an anode plate, a membrane electrode assembly, a cathode plate and a sealant. The anode plate (except the anode surface) or the cathode plate (except the cathode surface) respectively contains a smooth surface (i.e., a side without heat dissipation teeth) or a heat dissipation surface (i.e., a side with heat dissipation teeth); the anode plate can contain an anode surface and a heat dissipation surface, and the cathode plate can contain a cathode surface and a smooth surface, or the anode plate can contain an anode surface and a smooth surface, and the cathode plate can contain a cathode surface and a heat dissipation surface. The metal plate of the cathode plate or the anode plate can be one or more of a silver plate, a copper plate, an aluminum plate, and a stainless steel plate. It can be preferred to use a combination of a cathode plate (cathode surface + heat dissipation surface) as a graphite plate and an anode plate (anode surface + smooth surface) as a metal plate, or it can be preferred to use a combination of a cathode plate (cathode surface + smooth surface) as a metal plate and an anode plate (anode surface + heat dissipation surface). The membrane electrode assembly is sealed in the fuel cell, and the upper and lower sides of the membrane electrode assembly correspond to the anode surface and the cathode surface, respectively, and the flow channels are fine. At the same time, the heat dissipation surface of the graphite plate (cathode heat dissipation plate) with sparse flow channels in the single cell is offset against the smooth surface of the metal plate (anode heat dissipation plate) of the adjacent cell, which ensures sufficient heat dissipation of the fuel cell and plays a good sealing role; at the same time, the heat dissipation surface and the smooth surface offset can also increase the contact between the single cells, reduce the ohmic internal resistance, and improve the performance of the fuel cell.

[0063] Figure 4 FIG. 1 is a schematic diagram showing the contact surface of adjacent cells in a fuel cell stack according to an embodiment of the present invention. Figure 4 As shown, the heat dissipation teeth 410 on the anode heat dissipation plate 400 are in direct contact with (the light surface of) the cathode heat dissipation plate 500 of the adjacent single cell. Optionally, the anode heat dissipation plate 400 is further provided with air distribution holes 710 and hydrogen distribution holes 720.

[0064] Of course, the heat dissipation teeth on the cathode heat dissipation plate may also be in direct contact with (the light surface of) the anode heat dissipation plate of the adjacent single cell.

[0065] According to another aspect of the present invention, a fuel cell stack is provided, which includes a mounting frame and a plurality of fuel cell cells, wherein the fuel cell cells are arranged on the mounting frame.

[0066] Figure 5 A schematic diagram of the three-dimensional structure of a fuel cell stack according to an embodiment of the present invention is shown. Figure 6 FIG. 1 is a schematic diagram of a fuel cell stack according to an embodiment of the present invention. Figure 5 and Figure 6 As shown, the fuel cell cell 10 is disposed on a mounting frame 20 , and a gas source 30 is also disposed on one side of the fuel cell cell 10 .

[0067] Figure 7 A performance data comparison chart of a fuel cell stack according to an embodiment of the present invention is shown in the non-pressurized and non-humidified state and the pressurized and humidified state.

[0068] Since the cathode of the fuel cell stack according to the embodiment of the present invention is closed, the cathode can be supplied with air by a blower or an air compressor to provide high-pressure gas. A humidification tank can be used to humidify the cathode reaction gas to improve the proton conductivity of the membrane electrode assembly and increase the tolerance to high temperature, thereby improving the electrical performance of the air-cooled fuel cell stack and achieving a breakthrough in high-power fuel cell air-cooled stacks. Figure 7 It can be seen that under non-pressurized and non-humidified conditions, the rated power of a single stack can reach 10kW; under pressurized and humidified conditions, the rated power of a single stack can break through to 15kW, successfully achieving a technical breakthrough in high-power air-cooled stacks. Under non-pressurized and non-humidified conditions, the average voltage is 0.66V at a current density of 0.7A / cm2; under pressurized and humidified conditions, stable operation can be achieved at an average voltage of 0.66V at a current density of 1A / cm2.

[0069] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0070] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. Obviously, many modifications and changes can be made based on the above description. This specification selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present invention, so that those skilled in the art can make good use of the present invention and the modified use based on the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A fuel cell cell, comprising: Membrane electrode assembly; an anode plate and a cathode plate, wherein the anode plate and the cathode plate are respectively located on two sides of the membrane electrode assembly; an anode heat sink, the anode heat sink being located on one side of the anode plate, the anode plate being interposed between the anode heat sink and the membrane electrode assembly; as well as a cathode cooling plate, the cathode cooling plate being located on one side of the cathode plate, the cathode plate being interposed between the cathode cooling plate and the membrane electrode assembly, Wherein, the fuel cell single cell is of cathode-sealed type; The surface of the anode heat sink facing away from the anode plate is provided with heat dissipation teeth, and the heat dissipation teeth are used for direct contact with the cathode heat sink of the adjacent fuel cell cell; the surface of the anode heat sink close to the anode plate is a plane; the surface of the cathode heat sink facing away from the cathode plate is a plane; or The cathode heat sink is provided with heat dissipation teeth on the surface facing away from the cathode plate, and the heat dissipation teeth are used for direct contact with the anode heat sink of the adjacent fuel cell cell; the surface of the cathode heat sink close to the cathode plate is a plane; the surface of the anode heat sink facing away from the anode plate is a plane.

2. The fuel cell according to claim 1, wherein: When the anode heat sink is provided with heat dissipation teeth on the surface of the side away from the anode plate, the cathode heat sink is provided with grooves on the surface of the side close to the cathode plate; or When the cathode heat dissipation plate is provided with heat dissipation teeth on the surface of the side away from the cathode plate, the anode heat dissipation plate is provided with grooves on the surface of the side close to the anode plate.

3. The fuel cell according to claim 1, wherein: The fuel cell unit cell further comprises: A first seal is provided between the anode cooling plate and the cathode cooling plate and is used for sealing the membrane electrode assembly.

4. The fuel cell according to claim 1, wherein: The fuel cell unit cell further comprises: A second seal is located between the anode heat dissipation plate and the cathode heat dissipation plate of an adjacent fuel cell unit cell and / or between the cathode heat dissipation plate and the anode heat dissipation plate of an adjacent fuel cell unit cell.

5. The fuel cell according to claim 1, wherein: The cathode plate is a graphite plate, and the anode plate is a metal plate; The cathode heat sink and / or the anode heat sink is a metal plate, and the metal plate includes at least one selected from a silver plate, a copper plate, an aluminum plate and a stainless steel plate.

6. The fuel cell according to claim 1, wherein: The cathode plate is located in the closed cavity, and the fuel cell cell further comprises: A gas source is communicated with the closed cavity to provide reaction gas to the cathode plate.

7. The fuel cell according to claim 1, wherein: The heat dissipation teeth are strip-shaped, and the length direction of the heat dissipation teeth is the same as the width direction of the cathode heat dissipation plate and / or the anode heat dissipation plate.

8. The fuel cell according to claim 1, wherein: The width of the heat dissipation teeth is between 1 mm and 5 mm, and the height of the heat dissipation teeth is between 1 mm and 5 mm.

9. The fuel cell according to claim 8, wherein: A heat dissipation channel is formed between adjacent heat dissipation teeth, and the width of the heat dissipation channel is between 1 mm and 8 mm.

10. A fuel cell stack, comprising: Mounting frame; as well as The fuel cell cell according to any one of claims 1 to 9, wherein the fuel cell cell is arranged on the mounting frame.

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