A sealing structure, a fuel cell stack and a vehicle

Abstract

The present application discloses a sealing structure, a fuel cell stack and a vehicle. The sealing structure provided by the present application is applied between the core and the current collecting plate of the fuel cell stack. The sealing structure includes at least one pseudo membrane electrode and at least one plate unit alternately stacked. The pseudo membrane electrode is similar to the membrane electrode structure in the core, except that an electrochemical reaction cannot be performed. A sealing ring is provided on the pseudo membrane electrode, and the sealing ring has the same structure as the sealing ring inside the core, so that the sealing ring on the end side of the core and the sealing ring inside the core can be used interchangeably. On the one hand, the types of sealing ring designs are reduced, the mold cost is reduced, and the assembly process is simpler; on the other hand, because the sealing rings are the same, under the compression of the stack fastening assembly, the deformation of each sealing ring and the sealed area are basically the same, which can minimize the leakage of fluid media, especially hydrogen, in the stack.

Description

Technical Field

[0001] The present application belongs to the field of fuel cell technology, and specifically relates to a sealing structure, a fuel cell stack and a vehicle. Background Art

[0002] Proton exchange membrane fuel cell is a power generation device that uses hydrogen as fuel to directly convert chemical energy into electrical energy. Fuel cells have the advantages of high energy density, fast startup speed, low operating temperature, and no pollution, which makes them have potential application value in the field of new energy vehicles. The structure of a fuel cell stack is usually composed of hundreds of membrane electrodes, bipolar plates and seals stacked together. The end plates, insulating plates and current collectors on both sides apply fastening force, collect output energy, isolate high voltage, etc. The end plates of the stack are fastened and connected by strapping, tie rods, screws, etc. to form a fuel cell stack. Inside the fuel cell stack, the reaction gas (hydrogen and air) and the coolant are distributed to each single cell through the main pipe port of the bipolar plate. Therefore, the size of the main pipe port directly affects the flow resistance of the three chambers of the stack. Inside each single cell, hydrogen and air are evenly distributed through the flow channels on the anode side and the cathode side, respectively, and are transferred to the membrane electrode. Under the action of the catalysts on the cathode and anode on both sides of the proton exchange membrane inside the membrane electrode, the cathode and anode reaction media undergo electrochemical reactions to convert chemical energy into electrical energy.

[0003] The stack sealing structure design is of great significance to the stack sealing performance and lifespan, preventing the fuel cell stack from being affected by the external environment and playing the role of waterproof, dustproof and insulating. Due to the defects in the current stack sealing materials and sealing structure design, it is impossible for the stack to be completely free of hydrogen leakage. Therefore, how to optimize the stack sealing design and prevent the stack gas from leaking is of great significance to ensure the safety of the stack. Summary of the invention

[0004] In order to solve the above-mentioned technical problems, the present application provides a sealing structure, a fuel cell stack and a vehicle, which are used to solve the airtightness of the fuel cell stack, ensure the safety and reliability of the fuel cell stack during actual use, and facilitate the process assembly of the entire stack.

[0005] The technical solution adopted to achieve the purpose of the present application is a sealing structure applied between the core and the collecting plate of a fuel cell stack, wherein the sealing structure includes at least one dummy membrane electrode and at least one electrode unit alternately stacked; the dummy membrane electrode is a membrane electrode structure provided with a sealing ring and unable to carry out electrochemical reaction, and the sealing ring has the same structure as the sealing ring of the core.

[0006] In some embodiments, the pseudo membrane electrode includes a frame, a support layer and the sealing ring, the frame is arranged on the periphery of the support layer, and the sealing ring is connected to the frame.

[0007] In some embodiments, the sealing ring is integrally formed with the frame.

[0008] In some embodiments, a convex portion protruding outward is provided in the middle of the sealing ring.

[0009] In some embodiments, the electrode plate unit includes two unipolar plates, and at least one of the unipolar plates is a pseudo unipolar plate through which a fluid medium cannot flow.

[0010] In some embodiments, the number of the pseudo membrane electrode and the number of the polar plate units are both more than two, and the polar plate unit located at the end includes a monopolar plate and the pseudo monopolar plate.

[0011] In some embodiments, the monopolar plate and the pseudo-monopolar plate are both provided with at least two fluid openings, and the at least two fluid openings are symmetrically distributed at both ends of the long side direction of the bipolar plate; and the monopolar plate is provided with a flow channel.

[0012] In some embodiments, six fluid ports are provided on the pseudo unipolar plate, the six fluid ports are centrally symmetrical, and at least one of the six fluid ports is not connected to the flow channel.

[0013] Based on the same inventive concept, the present application also provides a fuel cell stack, including a core, wherein the core includes at least two membrane electrodes and at least two bipolar plates alternately stacked; the above-mentioned sealing structure is provided at at least one end of the core along the stacking direction; the side of the sealing structure close to the collecting plate is a false membrane electrode; the side of the sealing structure close to the core is a polar plate unit, and the polar plate unit is in contact with the membrane electrode at the end of the core.

[0014] In some embodiments, the sealing structure is provided at both ends of the core along the stacking direction, and the sealing structures at both ends are the same.

[0015] In some embodiments, the pseudo membrane electrode has the same structure as the membrane electrode when the CCM three-in-one assembly is not provided.

[0016] In some embodiments, two pole tabs are disposed on the bipolar plate, and the two pole tabs are respectively located on two opposite sides of the bipolar plate.

[0017] In some embodiments, the two pole tabs are staggered, or the two pole tabs are centrally symmetrically distributed.

[0018] In some embodiments, the two electrode tabs are respectively located on two short sides of the bipolar plate.

[0019] Based on the same inventive concept, the present application also provides a vehicle, comprising the above-mentioned fuel cell stack.

[0020] It can be seen from the above technical solution that the sealing structure provided by the present application is applied between the core and the current collecting plate of the fuel cell stack. The sealing structure includes at least one pseudo membrane electrode and at least one plate unit alternately stacked. The pseudo membrane electrode is similar to the membrane electrode structure in the core, except that an electrochemical reaction cannot be carried out. A sealing ring is provided on the pseudo membrane electrode, and the sealing ring has the same structure as the sealing ring inside the core. Therefore, the sealing ring on the end side of the core and the sealing ring inside the core can be used interchangeably. On the one hand, the types of sealing ring designs are reduced, the mold cost is reduced, and the assembly process is simpler; on the other hand, because the sealing rings are the same, under the compression of the stack fastening assembly, the deformation of each sealing ring and the sealed area are basically the same, which can minimize the leakage of fluid media, especially hydrogen, in the stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is an exploded view of the sealing structure in Example 1 of the present application.

[0022] Figure 2 for Figure 1 Schematic diagram of the structure of the pseudo membrane electrode in the sealed structure.

[0023] Figure 3 for Figure 2 Schematic diagram of the structure of the sealing ring in the pseudo membrane electrode.

[0024] Figure 4 for Figure 3 End face structure diagram of the sealing ring.

[0025] Figure 5 for Figure 1 Schematic diagram of the structure of the bipolar plate in the sealed structure.

[0026] Figure 6 for Figure 5 Exploded view of the bipolar plate.

[0027] Figure 7 This is a schematic diagram of the structure of the fuel cell stack in Example 2 of the present application.

[0028] Figure 8 for Figure 7 Schematic diagram of the structure of the core in a fuel cell stack.

[0029] Fig. 9 for Figure 8 Schematic diagram of the structure of the membrane electrode in a fuel cell stack.

[0030] Fig.10 This is a structural block diagram of the vehicle of Example 3 of the present application.

[0031] Explanation of the reference numerals: 10 - sealing structure; 11 - pseudo membrane electrode; 12 - plate unit; 13 - sealing ring, 131 - convex portion; 14 - pseudo bipolar plate, 141 - fluid port, 142 - pole ear; 15 - pseudo unipolar plate; 16 - frame; 17 - support layer.

[0032] 100-fuel cell stack; 110-intake end plate; 120-core, 121-membrane electrode, 122-bipolar plate; 130-blind end plate; 140-fastening assembly; 150-disc spring support plate. DETAILED DESCRIPTION

[0033] In order to enable technicians in the technical field to which the present application belongs to understand the present application more clearly, the technical solution of the present application is described in detail below through specific embodiments in conjunction with the accompanying drawings.

[0034] In the related art, the stacking scheme of the fuel cell stack is: air intake end plate-insulating plate-current collecting plate-carbon paper-monopolar plate with sealing ring-core (membrane electrode-sealing ring-bipolar plate...bipolar plate-sealing ring-membrane electrode)-monopolar plate with sealing ring-carbon paper-current collecting plate-insulating plate-blind end plate. The sealing ring in the core is usually integrated with the membrane electrode. Therefore, the core part of the fuel cell stack has two sealing rings with different structures. The sealing ring production mold and the corresponding monopolar plate mold (the bipolar plate in the core does not have a sealing ring) are also different. Manual stacking or manual and mechanical coordinated stacking are required during stacking, and automated assembly cannot be achieved. In addition, in the monopolar plate with a sealing ring, the monopolar plate is a conductor, usually a metal plate, and the sealing ring is a non-metallic material. Therefore, the sealing ring can only be bonded to the monopolar plate, and there are process problems such as sealing ring positioning deviation and sealing ring slippage, which in turn affect the performance of the entire stack.

[0035] The embodiments of the present application provide a sealing structure, a fuel cell stack and a vehicle, which can solve the above technical problems to a certain extent, ensure the safety and reliability of the fuel cell stack during actual use, and facilitate the process assembly of the entire stack. The present application is described in detail below in conjunction with the accompanying drawings and specific embodiments:

[0036] Embodiment 1:

[0037] The present application embodiment provides a sealing structure 10, which is applied between the core 120 and the current collecting plate of the fuel cell stack 100, that is, used for sealing the end side of the core 120. Figures 1 to 6The sealing structure 10 includes at least one pseudo membrane electrode 11 and at least one plate unit 12 which are alternately stacked. The pseudo membrane electrode 11 is similar in structure to the membrane electrode 121 in the core 120, except that it cannot undergo an electrochemical reaction. A sealing ring 13 is provided on the pseudo membrane electrode 11, and the sealing ring 13 has the same structure as the sealing ring inside the core 120. Thus, the sealing ring 13 of the end side seal and the sealing ring inside the core 120 can be used interchangeably. On the one hand, the types of sealing ring designs are reduced, the mold cost is reduced, and the assembly process is simpler. On the other hand, since the sealing rings are the same, under the compression of the stack fastening assembly 140, the deformation of each sealing ring and the sealed area are basically the same, which can minimize the leakage of the fluid medium in the stack, especially hydrogen.

[0038] Specifically, in the sealing structure 10, the pseudo membrane electrode 11 and the plate unit 12 are parallel to each other, and along the direction perpendicular to the pseudo membrane electrode 11 and the plate unit 12, that is, the stacking direction of the stack, each pseudo membrane electrode 11 and each plate unit 12 are alternately stacked, and the overall structure is similar to the core 120, and the number of pseudo membrane electrodes 11 and the plate unit 12 is the same. For example, in some embodiments, the sealing structure 10 includes one pseudo membrane electrode 11 and one plate unit 12; in other embodiments, the sealing structure 10 may include three pseudo membrane electrodes 11 and three plate units 12.

[0039] See also Figures 2 to 4 , the pseudo membrane electrode 11 is a membrane electrode 121 structure that cannot generate electricity through electrochemical reaction, that is, the pseudo membrane electrode 11 is obtained by structural modification of the membrane electrode 121. Specifically, in some embodiments, the membrane electrode 121 can be a five-in-one component, including a CCM three-in-one component and a GDL gas diffusion layer (or GDL for short) located on both sides. The GDL gas diffusion layer is composed of a support layer 17 and a microporous layer. The support layer 17 material is mainly porous carbon fiber paper, carbon fiber woven fabric, carbon fiber non-woven fabric and carbon black paper. The microporous layer is usually composed of conductive carbon black and a hydrophobic agent. In some embodiments, the membrane electrode 121 can be a seven-in-one component, including the above-mentioned five-in-one component and a frame 16 located on both sides. The outer contour of the frame 16 is consistent with the outer contour of the bipolar plate. The frame 16 is an insulating material, usually plastic, and a sealing ring 13 is usually integrally formed on the frame 16.

[0040] The CCM three-in-one assembly is the place where the electrochemical reaction occurs in the membrane electrode 121, and specifically includes a proton exchange membrane and a catalyst layer located on both sides. The pseudo membrane electrode 11 cannot perform an electrochemical reaction, which may be specifically due to the lack of a proton exchange membrane and / or a catalyst layer. The lack of a catalyst layer may be the lack of a single-sided catalyst layer or the lack of a double-sided catalyst layer. In the present embodiment, the pseudo membrane electrode 11 is a membrane electrode structure after the CCM in the membrane electrode 121 is cancelled, that is, the pseudo membrane electrode 11 includes a frame 16, a support layer 17 and a sealing ring 13, and the frame 16 is arranged on the periphery of the support layer 17. In some embodiments, the pseudo membrane electrode 11 includes a frame 16, a GDL and a sealing ring 13, and a microporous layer is also provided outside the support layer 17. In the present embodiment, the support layer 17 specifically adopts carbon paper.

[0041] See also Figures 2 to 4 , a sealing ring 13 is provided on the pseudo membrane electrode 11, and the sealing ring 13 is specifically connected to the frame 16. The shape, material, and various dimensional parameters of the sealing ring 13 are the same as those of the sealing ring in the core 120, and the fixing method of the sealing ring 13 on the pseudo membrane electrode 11 is also the same as that of the sealing ring 13 in the core 120. In this embodiment, the sealing ring 13 and the frame 16 are integrally formed. Specifically, the sealing ring 13 and the frame 16 are integrally formed by injection molding. The sealing ring 13 and the frame 16 are made of different materials and are integrally formed by injection molding, thereby reducing process problems such as positioning deviation and slippage of the end side sealing ring 13, and improving the convenience of assembling the entire stack.

[0042] To improve sealing performance and further reduce the risk of leakage, refer to Figure 3 and Figure 4 In this embodiment, the middle of the sealing ring 13 is provided with a convex portion 131 protruding outward, and the convex portion 131 is in arc transition with the main body portion, and the two edges of the main body portion are also in arc transition, such as Figure 4 As shown. The cross-sectional shape of the sealing ring 13 is a convex shape, and the convex part 131 can produce a larger deformation under the action of the fastening force, thereby improving the sealing performance. The convex part 131 can be provided with only one, that is, a single-peak sealing ring 13; or multiple convex parts 131 can be provided, such as a double-peak sealing ring 13, a triple-peak sealing ring 13, etc., which is not limited in this application.

[0043] Specifically, the plate unit 12 in the sealing structure 10 can be a true bipolar plate or a false bipolar plate 14. The false bipolar plate 14 is a plate structure that cannot allow fluid medium to flow into the flow field. The false bipolar plate 14 can be a false monopolar plate 15 in which one of the monopolar plates is a false monopolar plate 15, or both monopolar plates are false monopolar plates 15. The plate unit 12 located between the two false membrane electrodes 11 in the sealing structure 10 is a false bipolar plate 14, please refer to Figure 5 and Figure 6The middle pseudo bipolar plate 14 includes two pseudo unipolar plates 15, one of which is an anode plate and the other is a cathode plate. The outer plate unit 12 in the sealing structure 10 includes only one pseudo unipolar plate 15 and the other is a true unipolar plate for providing a hydrogen field or an air field.

[0044] In this embodiment, the number of the pseudo membrane electrode 11 and the polar plate unit 12 is more than two, and the polar plate unit 12 located between two adjacent pseudo membrane electrodes 11 is a pseudo bipolar plate 14, that is, the sealing structure 10 is: pseudo membrane electrode 11-pseudo bipolar plate 14 (pseudo unipolar plate 15-pseudo unipolar plate 15)······-pseudo membrane electrode 11-pseudo bipolar plate 14 (pseudo unipolar plate 15-real unipolar plate). Among them, a real unipolar plate is provided on the side of the sealing structure 10 close to the core 120, and air or hydrogen flows on the gas field side of the unipolar plate. The air or hydrogen undergoes an electrochemical reaction in the membrane electrode 121 at the end of the core 120, and the pseudo unipolar plate 15 also plays the role of supporting the membrane electrode 121. The side of the sealing structure 10 close to the current collecting plate is a pseudo membrane electrode 11, and the pseudo membrane electrode 11 plays the role of end-side sealing.

[0045] At least two fluid openings 141 are provided on the unipolar plate and the pseudo unipolar plate 15, and at least two fluid openings 141 are symmetrically distributed at both ends of the long side direction of the pseudo bipolar plate 14. The fluid field of the unipolar plate and the pseudo unipolar plate 15 includes a distribution area, an active area and a confluence area, and the distribution area, the active area and the confluence area are distributed in sequence along the long side direction of the pseudo bipolar plate 14. For the true bipolar plate, the fluid medium (reactant gas and coolant) flows into the interior of the bipolar plate from the fluid opening 141 at one end of the bipolar plate, and is distributed through the distribution area for expansion flow distribution and evenly distributed to the active area. The distribution area of ​​the active area is large, and the electrochemical reaction of hydrogen and oxygen mainly occurs in the active area. A flow channel is provided in the active area. When the fluid medium flows in the flow channel, it is evenly dispersed to the entire active area. The fluid converges through the confluence area and flows out of the bipolar plate through the fluid opening 141 at the other end of the bipolar plate. As for the pseudo bipolar plate 14 , since it includes at least one pseudo unipolar plate 15 , the fluid passage 141 of the pseudo unipolar plate 15 is not connected with the fluid field, so the fluid medium cannot enter the fluid field.

[0046] See also Figure 5 and Figure 6 In this embodiment, six fluid openings 141 are provided on the monopolar plate and the pseudo monopolar plate 15, namely: an oxidant inlet, a reductant inlet, a coolant inlet, an oxidant outlet, a reductant outlet, and a coolant outlet. Specifically, the oxidant inlet, the reductant outlet and the coolant inlet, as well as the oxidant outlet, the reductant inlet and the coolant outlet are respectively distributed on the two short sides of the pseudo bipolar plate 14, and are centrally symmetrically distributed, so that the plate area utilization rate is high.

[0047] In the core 120, the two sides of the anode plate are the water field side and the hydrogen field side, respectively, so the reductant inlet, the reaction gas distribution area, the reaction gas flow field active area, the reaction gas confluence area and the reductant outlet in the anode plate of the core 120 are connected in sequence. Since the two sides of the cathode plate are the water field side and the air field side, respectively, the oxidant inlet reaction gas distribution area, the reaction gas flow field active area, the reaction gas confluence area and the oxidant outlet in the cathode plate of the core 120 are connected in sequence. The coolant inlet, the coolant distribution area, the coolant flow field active area, the coolant confluence area and the coolant outlet in the anode plate and the cathode plate of the core 120 are connected in sequence.

[0048] In the sealing structure 10, the pseudo membrane electrode 11 does not perform an electrochemical reaction, so there is no need for hydrogen and oxygen to circulate on the gas field side of the pseudo bipolar plate 14. Since the pseudo membrane electrode 11 does not perform an electrochemical reaction and does not generate heat, there is no need to pass cooling water into the pseudo bipolar plate 14 for cooling. Therefore, the fluid port 141 in the sealing structure 10 can be disconnected from the flow channel. In this embodiment, six fluid ports 141 are provided on both the anode plate and the cathode plate, and the six fluid ports 141 are centrally symmetrical, and at least one of the six fluid ports 141 is disconnected from the flow channel.

[0049] Specifically, the fluid opening 141 is not connected to the flow channel, and the corresponding flow guide structure ("layer-over" structure or "straight-through" structure) may not be provided between the fluid opening 141 of the pseudo unipolar plate 15 and the fluid transition zone, or the pseudo bipolar plate 14 is welded as a whole to block the flow channel inlet and outlet. In some embodiments, the oxidant inlet, the reductant inlet, the oxidant outlet and the reductant outlet may be arranged to be not connected to the flow channel, but the coolant inlet and the coolant outlet are connected to the flow channel. When the fuel cell is working, cooling water is introduced into the sealing structure 10, which can achieve the effect of low-temperature cold start, warm-up, or improving the end-side effect of the core 120.

[0050] Embodiment 2:

[0051] Based on the same inventive concept, this embodiment provides a fuel cell stack 100, see Figures 7 to 9 The fuel cell stack 100 includes a core 120, and the core 120 includes at least two membrane electrodes 121 and at least two bipolar plates 122 that are alternately stacked; the membrane electrode 121 and the bipolar plate 122 are parallel to each other and are parallel to the end plate of the stack. Current collecting plates, insulating plates and end plates are sequentially provided on both sides of the stack. In some embodiments, the insulating plates and the end plates can be integrated into one. In the fuel cell stack 100 provided in this embodiment, the sealing structure 10 of the above-mentioned embodiment 1 is provided at least at one end of the core 120 along the stacking direction, and the pseudo-unipolar plate 15 of the sealing structure 10 is in contact with the membrane electrode 121 at the end of the core 120.

[0052] In the fuel cell, the end close to the reaction medium input end is defined as the inlet end, and the end far from the reaction medium input end is defined as the blind end. Correspondingly, the end plate at the inlet end is defined as the inlet end plate 110, and the end plate at the blind end is defined as the blind end plate 130. Thus, the inlet end and / or the blind end of the core 120 are provided with the sealing structure 10 of the above-mentioned embodiment 1, the pseudo membrane electrode 11 of the sealing structure 10 is in contact with the current collecting plate, and the pseudo unipolar plate 15 of the sealing structure 10 is in contact with the membrane electrode 121 of the core 120.

[0053] In this embodiment, sealing structures 10 are provided at both ends of the core 120 along the stacking direction, and the sealing structures 10 at both ends are identical. Figure 7 The fuel cell stack 100 includes in sequence: an air intake end plate 110-insulating plate-current collecting plate-sealing structure 10 (a pseudo membrane electrode 11 with a sealing ring 13-a pseudo unipolar plate 15)-core 120 (membrane electrode 121-sealing ring 13-bipolar plate 122...bipolar plate 122-sealing ring 13-membrane electrode 121)-sealing structure 10 (a pseudo membrane electrode 11 with a sealing ring 13-a pseudo unipolar plate 15)-current collecting plate-insulating plate-blind end plate 130, and then the fastening force is provided by the fastening assembly 140. In some embodiments, a disc spring and a disc spring support plate 150 are also provided on the blind end side of the stack.

[0054] Specifically, the structure of the dummy membrane electrode 11 in the sealing structure 10 is the same as that of the membrane electrode 121 of the core 120 when the CCM three-in-one assembly is not set. That is, the only difference between the dummy membrane electrode 11 in the sealing structure 10 and the membrane electrode 121 of the core 120 is that the dummy membrane electrode 11 in the sealing structure 10 is not set with the CCM three-in-one assembly.

[0055] Specifically, the structure of the dummy bipolar plate 14 in the sealing structure 10 is similar to that of the bipolar plate 122 of the core 120, at least in terms of the outer contour. In this embodiment, the structure of the dummy bipolar plate 14 in the sealing structure 10 is exactly the same as that of the bipolar plate 122 of the core 120, so only one type of bipolar plate is needed for the entire stack, thereby reducing the number of molds. The dummy bipolar plate 14 is provided with two pole ears 142, which are respectively located on two opposite sides of the dummy bipolar plate 14, specifically, two long sides or two short sides.

[0056] In some embodiments, the two pole ears 142 are staggered, or the two pole ears 142 are symmetrical about the center. Specifically, the two pole ears 142 are respectively located on the two short sides of the bipolar plate, and the two pole ears 142 are symmetrical about the center, so that the pole ears are in the same position before and after the monopolar plate is rotated 180°, so that the pole ears are arranged in a single row. This ensures that no matter how the bipolar plate is placed, the pole ears 142 for output voltage can be provided on the short side. In some embodiments, the two pole ears 142 are staggered, that is, the positions of the two pole ears do not overlap after rotating 180°, thereby forming two rows of pole ears. Different arrangements of the pole ears can form different low-voltage wiring schemes. In the formed bipolar plate, it is only necessary to connect the low-voltage wiring harness on one side of the bipolar plate, so the pole ears on the other side need to be cut and removed.

[0057] Since the sealing structure 10 of the above-mentioned embodiment 1 is provided as the end side seal of the core 120, the fuel cell stack 100 has a simplified structure, high integration, and can realize automated assembly. At the same time, the specifications of the sealing ring 13 and the sealing ring 13 at the middle position of the core 120 can be universal, reducing the design types and reducing the mold cost. In addition, the membrane electrode 121 with the sealing ring 13 used for end side sealing can reduce the positioning deviation of the end side sealing ring 13, slippage and other process problems, improve the convenience of the whole stack assembly, and ensure that the fuel cell stack is reliable and highly adaptable. Other undetailed structures of the stack can refer to the relevant disclosure of the prior art and will not be described here.

[0058] Embodiment 3:

[0059] Based on the same inventive concept, this embodiment provides a vehicle, such as Fig.10 As shown, the vehicle includes at least one fuel cell stack 100 of the above-mentioned embodiment 2. Specifically, the vehicle includes a fuel cell power system, which includes a fuel cell system, a DC / DC converter, a drive motor and its motor controller, and an on-board energy storage device. The fuel cell system includes a fuel cell module and a fuel cell auxiliary system. The fuel cell system can work normally under the condition of an external fuel supply source. The fuel cell module includes at least one fuel cell stack 100 of the above-mentioned embodiment 2, that is, the fuel cell module can be a single stack solution or a multi-stack integrated solution.

[0060] In some embodiments, in order to encapsulate the fuel cell stack 100, the fuel cell module includes a shell having an installation cavity, and the fuel cell stack 100 is encapsulated in the installation cavity of the shell. In some embodiments, the fuel cell module also includes a high-voltage component for outputting electrical energy and a low-voltage component for control (such as a voltage inspection device, etc.) to output current and inspection signals to the outside. For a multi-stack integrated fuel cell module, a manifold assembly for uniformly distributing gas to each stack should also be included. This embodiment does not improve the specific structure of the fuel cell module other than the fuel cell stack 100, so the structure of the fuel cell module that has not been changed in this embodiment can refer to the prior art, and the specific content will not be described in detail here.

[0061] The fuel cell auxiliary system of the fuel cell system includes an air supply subsystem, a fuel supply subsystem, a thermal management subsystem and an automatic control system, wherein the air supply subsystem is used to provide air to each stack of the fuel cell module, and can optionally filter, humidify, pressure regulate and other aspects of the air, and the air supply subsystem is connected to the air inlet and air outlet of each stack of the fuel cell module; the fuel supply subsystem is used to provide fuel to each stack of the fuel cell module, and can optionally humidify, pressure regulate and other aspects of the fuel to convert it into a fuel gas suitable for operation in the fuel cell stack. Taking hydrogen as fuel, for example, the fuel supply subsystem is connected to the hydrogen inlet and hydrogen outlet of each stack of the fuel cell module; the thermal management subsystem is connected to each stack of the fuel cell module to provide coolant to cool and / or heat the stack, and to recycle water generated by the stack.

[0062] The automatic control system is electrically connected to the fuel cell module, the air supply subsystem, the fuel supply subsystem and the thermal management subsystem, respectively. The automatic control system is an assembly including sensors, actuators, valves, switches and control logic components, which ensures that the fuel cell system can operate normally without human intervention. In other embodiments, the fuel cell auxiliary system may also include a ventilation system for exhausting the gas in the housing of the fuel cell system to the outside by mechanical means. In this embodiment, the fuel cell auxiliary system in the fuel cell system has not been improved, so more detailed content can refer to the relevant disclosure of the prior art, which will not be described in detail here.

[0063] In the fuel cell power system, the DC / DC converter is electrically connected to each stack of the fuel cell system to achieve voltage conversion, and the voltage generated by each stack is adjusted and output to high-voltage devices such as the drive motor, the automobile air-conditioning compressor, and power storage devices such as batteries. The drive motor is electrically connected to the DC / DC converter to provide the torque required for the vehicle to travel; the motor controller is electrically connected to the drive motor to control the start, stop, torque output, etc. of the drive motor. The motor controller is connected to the vehicle control to receive the driving signal from the vehicle controller, and the motor controller can also be electrically connected to the automatic control system of the fuel cell system. The on-board energy storage device is used to store electrical energy to power other electronic devices in the vehicle. The on-board energy storage device is electrically connected to the DC / DC converter, for example, the on-board energy storage device is a battery.

[0064] In this embodiment, the DC / DC converter, the drive motor and its motor controller, and the on-board energy storage device in the fuel cell power system have not been improved. Therefore, more detailed contents can be referred to the relevant disclosure of the prior art and will not be elaborated here.

[0065] In addition, the vehicle also needs to include a transmission system and a fuel storage device for storing fuel. The transmission system transmits the torque of the drive motor to drive the wheels to rotate. The fuel storage device functions similarly to the fuel tank in a fuel vehicle. The fuel storage device is connected to the fuel supply subsystem of the fuel cell system through a pipeline.

[0066] Thus, the vehicle can be a hydrogen energy vehicle or a hydrogen energy + charging hybrid electric vehicle, and can be a family car, a bus, a truck, etc. Since the specific structure of the vehicle is not improved in this embodiment, the structure of the vehicle that has not been changed in this embodiment can refer to the prior art, and the specific content is not described here. Thus, the vehicle has all the features and advantages described above for the fuel cell power system, fuel cell system, fuel cell module, and fuel cell stack 100, which will not be repeated here.

[0067] According to the above content, the embodiments of the present application provide the following advantages:

[0068] (1) The sealing structure provided in the present application is applied between the core and the current collecting plate of a fuel cell stack. The sealing structure includes at least one pseudo-membrane electrode and at least one plate unit alternately stacked. A sealing ring is provided on the pseudo-membrane electrode, and the sealing ring has the same structure as the sealing ring inside the core, so that the sealing ring on the end side of the core and the sealing ring inside the core can be used interchangeably. On the one hand, the types of sealing ring designs are reduced, the mold cost is reduced, and the assembly process is simpler; on the other hand, because the sealing rings are the same, under the compression of the stack fastening assembly, the deformation of each sealing ring and the sealed area are basically the same, which can minimize the leakage of fluid media in the stack, especially hydrogen.

[0069] (2) The sealing structure provided in the present application, in which the sealing ring and the dummy membrane electrode are integrally formed, can reduce process problems such as positioning deviation and slippage of the end-side sealing ring, and improve the convenience of assembling the entire stack.

[0070] (3) The fuel cell stack provided in the present application has the above-mentioned sealing structure arranged at the end of the core, which can reduce the end-side effect, avoid the single cell (membrane electrode + bipolar plate) at the end of the core from dissipating heat too quickly and causing low output voltage, and improve the consistency of the output voltage of each single cell in the core.

[0071] (4) The fuel cell stack provided in the present application is provided with the above-mentioned sealing structure at the end of the core. The above-mentioned sealing structure has a certain thermal insulation performance and can insulate the end side of the core during low-temperature cold start, so that the core can reach the optimal working state as soon as possible.

[0072] (5) The fuel cell stack provided in the present application has the above-mentioned sealing structure arranged at the end of the core. Since the fastening force of the core tends to decrease from the end to the middle, the fastening force borne by the single cells in the middle of the core is basically the same. By arranging the above-mentioned sealing structure at the end of the core, the sealing structure can be made to withstand a larger fastening force, and the sealing structure forms a transition zone for the fastening force. The fastening force borne by each single cell in the entire core is basically the same.

[0073] (6) The fuel cell stack provided in the present application has the above-mentioned sealing structure arranged at the end of the core, so that there are both fake cells and real cells between the current collecting plates at both ends, and the fake cells are located at the ends of the real cells. When setting a low-voltage inspection connector, the cells at the ends are often difficult to connect due to the small gap between adjacent cells. The present application sets a sealing structure so that the ends are fake cells that do not generate electricity, thereby ensuring that the cells in the core are connected normally.

[0074] Although the preferred embodiments of the present application have been described, those skilled in the art may make other changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0075] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include these modifications and variations.

Claims

1. A fuel cell stack, comprising a core, wherein the core comprises at least two membrane electrodes and at least two bipolar plates alternately stacked; characterized in that: The membrane electrode of the core is provided with an integrally formed sealing ring, and the end side of the core is a membrane electrode provided with a sealing ring; a sealing structure is provided at least at one end of the core along the stacking direction, and the sealing structure is arranged between the core and the collecting plate of the fuel cell stack, and the sealing structure includes at least one dummy membrane electrode and at least one plate unit alternately stacked, and the side of the sealing structure close to the core is a plate unit provided with a true unipolar plate and a dummy unipolar plate, and the plate unit is in contact with the membrane electrode at the end of the core, and the side of the sealing structure close to the collecting plate is a dummy membrane electrode; the dummy membrane electrode is a membrane electrode structure provided with a sealing ring and unable to perform electrochemical reaction, and the dummy membrane electrode includes a frame, a supporting layer and the sealing ring, and the frame is arranged on the periphery of the supporting layer, and the sealing ring is integrally formed with the frame, and the sealing ring has the same structure as the sealing ring of the membrane electrode of the core.

2. The fuel cell stack according to claim 1, characterized in that: A convex portion protruding outwards is provided in the middle of the sealing ring.

3. The fuel cell stack according to claim 1, characterized in that: The polar plate unit includes two monopolar plates, and at least one of the monopolar plates is a pseudo monopolar plate through which a fluid medium cannot flow.

4. The fuel cell stack according to claim 3, characterized in that: The number of the pseudo membrane electrode and the number of the polar plate units are both more than two, and the polar plate unit located at the end includes a monopolar plate and the pseudo monopolar plate.

5. The fuel cell stack according to claim 4, characterized in that: The monopolar plate and the pseudo-monopolar plate are both provided with at least two fluid openings, and the at least two fluid openings are symmetrically distributed at both ends of the long side direction of the bipolar plate; the monopolar plate is provided with a flow channel.

6. The fuel cell stack according to claim 5, characterized in that: Six fluid ports are arranged on the pseudo monopolar plate, the six fluid ports are centrally symmetrical, and at least one of the six fluid ports is not connected to the flow channel.

7. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The sealing structures are provided at both ends of the core along the stacking direction, and the sealing structures at both ends are the same.

8. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The pseudo membrane electrode has the same structure as the membrane electrode when the CCM three-in-one assembly is not provided.

9. The fuel cell stack according to any one of claims 1 to 6, characterized in that: The bipolar plate is provided with two pole ears, and the two pole ears are respectively located on two opposite sides of the bipolar plate.

10. The fuel cell stack according to claim 9, characterized in that: The two pole tabs are staggered or centrally symmetrically distributed.

11. The fuel cell stack according to claim 9, characterized in that: The two pole tabs are respectively located on two short sides of the bipolar plate.

12. A vehicle, characterized in that: A fuel cell stack comprising the fuel cell stack described in any one of claims 1 to 11.

Images