A hydrogen fuel cell stack

Abstract

The application provides a hydrogen fuel cell stack, comprising: an upper cover plate; a lower cover plate; a plurality of bipolar plates arranged between the upper cover plate and the lower cover plate, the plurality of bipolar plates being stacked together, one side of each bipolar plate being a negative electrode and the other side being a positive electrode, in adjacent bipolar plates, the positive electrode or the negative electrode of one bipolar plate being in contact with the negative electrode or the positive electrode of the other bipolar plate; each bipolar plate comprising a positive electrode plate, a membrane electrode and a negative electrode plate stacked in sequence along the stacking direction of the plurality of bipolar plates; a first air circulation loop and a second air circulation loop being arranged on the mutually facing sides of the positive electrode plate and the negative electrode plate respectively, the first air circulation loop and the second air circulation loop both being curved in the shape of a Chinese character 'jia', one end of the first air circulation loop being in communication with a first air outlet and the other end being in communication with a first air inlet, one end of the second air circulation loop being in communication with a first hydrogen outlet and the other end being in communication with a first hydrogen inlet.

Description

Technical Field

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

[0002] Fuel cells have the advantage of being pollution-free and are currently being used in many industries. As the most core technology in the fuel cell system, the performance of the stack plays a decisive role.

[0003] The patent application of the invention with the publication number CN113178593A discloses a stack structure of a proton exchange membrane fuel cell, which adopts a water-cooling method. Although it can meet certain requirements, it will greatly limit the use of fuel cells in some places where water is inconvenient, such as vehicles. Summary of the Invention

[0004] The main object of the present invention is to provide a hydrogen fuel cell stack to solve the above technical problems.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a hydrogen fuel cell stack, comprising:

[0006] An upper cover plate;

[0007] A lower cover plate;

[0008] A plurality of bipolar plates, which are arranged between the upper cover plate and the lower cover plate and stacked together. One side of each bipolar plate is the negative electrode and the other side is the positive electrode. In adjacent bipolar plates, the positive electrode or negative electrode of one bipolar plate contacts the negative electrode or positive electrode of the other bipolar plate; each bipolar plate includes a positive electrode plate, a membrane electrode, and a negative electrode plate stacked in sequence along the stacking direction of the plurality of bipolar plates;

[0009] When observing along the stacking direction, the bipolar plate is rectangular. At both ends of the bipolar plate along the length direction of the rectangle, a first air outlet and a first hydrogen inlet are provided at one end, and a first hydrogen outlet and a first air inlet are provided at the other end. The first air outlet and the first air inlet are arranged on one diagonal of the rectangle, and the first hydrogen inlet and the first hydrogen outlet are arranged on the other diagonal of the rectangle;

[0010] A first ventilation circuit and a second ventilation circuit are respectively provided on the mutually facing sides of the positive electrode plate and the negative electrode plate. The first ventilation circuit and the second ventilation circuit are both bent in a "U" shape. One end of the first ventilation circuit is connected to the first air outlet, and the other end is connected to the first air inlet. One end of the second ventilation circuit is connected to the first hydrogen outlet, and the other end is connected to the first hydrogen inlet;

[0011] The positive plate and the negative plate are both at least partially made of carbon plate, and the first hydrogen circulation loop and the second hydrogen circulation loop are arranged on the corresponding carbon plate.

[0012] Preferably, a first conductive plate is arranged on the side of the positive plate facing away from the membrane electrode.

[0013] Preferably, a plastic frame is arranged on the side of the negative plate facing away from the membrane electrode, and a placing groove is formed on the plastic frame, the placing groove is hollow in the stacking direction, the placing groove has at least one, a metal sponge is placed in the placing groove, the thickness of the metal sponge is equal to or slightly greater than the depth of the placing groove, and one side of the metal sponge is in contact with the negative plate.

[0014] Preferably, a second conductive plate and a third conductive plate are arranged at the two ends of the bipolar plate group composed of a plurality of bipolar plates, the second conductive plate is located between the bipolar plate group and the upper cover plate, and the third conductive plate is located between the lower cover plate and the bipolar plate group; a second air outlet, a first water outlet, and a second air inlet are arranged on the third conductive plate, and in the stacking direction, the second air outlet is aligned with and communicates with the first air inlet, the first water outlet is aligned with and communicates with the first hydrogen outlet, and the second air inlet is aligned with and communicates with the first air outlet.

[0015] Preferably, a humidifying assembly is further included for humidifying the air entering the first air inlet from the second air outlet, the humidifying assembly is located between the third conductive plate and the lower cover plate, and the humidifying assembly includes at least one set of humidifying layers, the humidifying layers include a first humidifying layer, a diaphragm, and a second humidifying layer stacked together in sequence, the diaphragm separates the first humidifying layer from the second humidifying layer, the used air of the bipolar plate can enter the second humidifying layer, the air from the outside can enter the first humidifying layer, and the moisture in the second humidifying layer can enter the first humidifying layer through the diaphragm and humidify the air in the first humidifying layer.

[0016] Preferably, a first flow-through space, a third air outlet, a second water outlet, a sixth air outlet, a fifth air inlet, and a third air inlet are arranged on the first humidifying layer, the third air inlet and the first flow-through space communicate, the third air outlet also communicates with the first flow-through space, the air from the outside enters the first flow-through space from the third air inlet and exits from the third air outlet; the second water outlet is aligned with and communicates with the first water outlet, and the fifth air inlet is aligned with and communicates with the second air inlet.

[0017] Preferably, a first partition plate is arranged in the first flow-through space, the first partition plate is arranged at least in two, the two first partition plates are parallel to each other, and each first partition plate is provided with a notch, and the notches on the two first partition plates are arranged at opposite positions along the extension direction of the partition plate.

[0018] Preferably, the second humidifying layer is provided with a second flow-through space, a sixth air inlet, a fourth air inlet, a fourth air outlet, a third water outlet, and a fifth air outlet. The fourth air inlet communicates with the second flow-through space, and the second flow-through space simultaneously communicates with the fourth air outlet, which communicates with the outside. In the stacking direction, the fourth air inlet is aligned with the second air inlet and the first air outlet, the third water outlet is aligned with the first water outlet and the first hydrogen outlet, the fifth air outlet is aligned with and communicates with the third air outlet, the fourth air inlet is aligned with and communicates with the fifth air inlet, the sixth air inlet is aligned with and communicates with the third air inlet, and the fourth air outlet is aligned with and communicates with the sixth air outlet.

[0019] Preferably, the upper cover plate includes a cover body provided with a hydrogen inlet hole, a first mounting hole, and a second mounting hole. The outer end of the hydrogen inlet hole is provided with a pipe joint. The first mounting hole is used for mounting a solenoid valve, and the second mounting hole is used for mounting a pressure regulating valve. The hydrogen inlet hole communicates with the first mounting hole and the second mounting hole. The solenoid valve can control the opening and closing of the hydrogen inlet hole. The pressure regulating valve is used for controlling the gas pressure of hydrogen.

[0020] The upper cover plate is also provided with a hydrogen outlet hole aligned with and communicating with the first hydrogen inlet hole. Hydrogen from the pressure regulating valve enters the first hydrogen inlet hole through the hydrogen outlet hole. The upper cover plate is also provided with a hydrogen return hole aligned with and communicating with the first hydrogen outlet hole, and the hydrogen return hole also communicates with the hydrogen inlet hole.

[0021] and / or,

[0022] The lower cover plate is provided with an eighth air inlet, a seventh air inlet, a sixth air outlet, a fourth water outlet, a drain outlet, and an air pump. The air pump is arranged on the lower cover plate, and the air outlet of the air pump communicates with the eighth air inlet. The eighth air inlet communicates with the seventh air inlet. In the stacking direction, the seventh air inlet is aligned with and communicates with the sixth air inlet. In the stacking direction, the sixth air outlet is aligned with and communicates with the fourth air outlet. Used air is discharged through the fifth air outlet. In the stacking direction, the fourth water outlet is aligned with and communicates with the third water outlet. The drain outlet communicates with the fourth water outlet. A drain valve is arranged on the lower cover plate at a position corresponding to the drain outlet. By controlling the opening and closing of the drain valve, drainage can be achieved.

[0023] Preferably, the positive electrode plate includes a positive electrode outer frame, a positive electrode carbon plate arranged in the positive electrode outer frame, and a positive electrode conductive plate arranged on the side of the positive electrode outer frame away from the membrane electrode. The side of the positive electrode carbon plate facing the membrane electrode is provided with a positive electrode hydrogen circulation loop. The positive electrode hydrogen circulation loop is in the shape of a “U”. One end of the positive electrode hydrogen circulation loop communicates with the first air inlet, and the other end communicates with the first air outlet. The positive electrode conductive plate is in contact with the positive electrode carbon plate.

[0024] The negative plate comprises a negative outer frame, a negative carbon plate arranged in the negative outer frame, a negative conductive plate arranged on the side of the negative outer frame away from the membrane electrode, a negative gas passage is arranged on the side of the negative carbon plate facing the membrane electrode, the negative gas passage is in the shape of a Chinese character 'j', one end of the negative gas passage is in communication with the first hydrogen inlet, the other end is in communication with the first hydrogen outlet, the membrane electrode separates the positive gas passage and the negative gas passage, the negative carbon plate is in contact with the negative conductive plate, and the positive outer frame and the negative outer frame are both plastic;

[0025] Support frames are arranged on the two ends of the side of the negative conductive plate away from the membrane electrode along the length direction respectively, a placing groove is formed between the two support frames, a metal sponge is placed in the placing groove, and the positive conductive plate of a front bipolar plate is in contact with the metal sponge of a rear bipolar plate.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] 1) The bipolar plate of the present application uses metal sponge for heat dissipation, and the metal sponge also serves as a conductor, playing a dual role;

[0028] 2) The present application provides two kinds of bipolar plates, when the size of the stack is small, the bipolar plate with carbon plates for both the positive plate and the negative plate can be used, and when the size of the stack is large, the bipolar plate with carbon plates for part of the positive plate and the negative plate can be used, so as to reduce the material cost;

[0029] 3) The hydrogen gas of the present application can be reused, saving hydrogen gas;

[0030] 4) The present application has a humidifying layer, part of the water generated by the stack reaction is used to humidify the new air, and the humidified air helps the reaction of the stack. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 and Figure 2 is a perspective view of the stack of embodiment one of the present application;

[0032] Figure 3 is a perspective view of the bipolar plate of embodiment one;

[0033] Figure 4 is an enlarged view of A;

[0034] Figure 5 is a perspective view of the bipolar plate of embodiment one from another angle;

[0035] Figure 6 is a perspective view of the bipolar plate of embodiment one without the metal sponge;

[0036] Figure 7 is a structural diagram of the carbon plate of Example One;

[0037] Figure 8 is a structural diagram of the upper cover plate;

[0038] Figure 9 is a structural diagram of the humidifying assembly and the third conductive plate;

[0039] Figure 10 is a structural diagram of the humidifying assembly;

[0040] Figure 11 and Figure 12 is a structural diagram of the first humidifying layer;

[0041] Figure 13 and Figure 14 is a structural diagram of the second humidifying layer;

[0042] Figure 15 and Figure 16 is a structural diagram of the lower cover body;

[0043] Figure 17 and Figure 18 is a structural diagram of the bipolar plate of Example Two;

[0044] Figure 19 is an enlarged view of B;

[0045] Figure 20 is a structural diagram of the bipolar plate of Example Two with the positive conductive plate removed;

[0046] Figure 21 is a structural diagram of the negative electrode plate. DETAILED DESCRIPTION

[0047] The following description is presented to enable any person skilled in the art to practice the application as claimed. The preferred embodiments disclosed herein are only examples of the application and alternative variations thereof are contemplated as falling within the spirit and scope of the application.

[0048] Example One

[0049] As shown in Figures 1-16 , a hydrogen fuel cell stack includes an upper cover plate 1, a lower cover plate 2, and a plurality of bipolar plates 4 arranged between the upper cover plate 1 and the lower cover plate 2, the plurality of bipolar plates 4 being stacked, each bipolar plate 4 having a negative side and a positive side, and in adjacent bipolar plates 4, the positive side or the negative side of one bipolar plate 4 is in contact with the negative side or the positive side of the other bipolar plate 4, i.e., the plurality of bipolar plates 4 are connected in series.

[0050] Each bipolar plate 4 includes a positive electrode plate 404, a membrane electrode 405, and a negative electrode plate 403 stacked in sequence. Both the positive electrode plate 404 and the negative electrode plate 403 are made of carbon plates. The membrane electrode 405 separates the positive electrode plate 404 and the negative electrode plate 403 to prevent them from directly contacting each other. On the side of the positive electrode plate 404 facing away from the membrane electrode 405, a first conductive plate 411 is provided for conducting electricity. The first conductive plate 411 is made of a metal material and plays a role in protecting the carbon plate.

[0051] Ventilation circuits 410 are provided on the sides of the positive electrode plate 404 and the negative electrode plate 403 facing each other. The ventilation circuits 410 are bent in a "zigzag" shape to increase the circulation time of gas in the ventilation circuits 410 and improve the utilization rate of hydrogen. For the sake of description, the ventilation circuit 410 on the positive electrode plate 404 is called the first ventilation circuit, and the ventilation circuit 410 on the negative electrode plate 403 is called the second ventilation circuit. The membrane electrode 405 can separate the ventilation circuits 410 on the positive electrode plate 404 and the negative electrode plate 403, that is, the air and hydrogen in the two ventilation circuits 410 will not directly contact each other. The membrane electrode 405 is used to make hydrogen lose electrons and become hydrogen ions. The hydrogen ions pass through the membrane electrode 405 and react with oxygen in the air to form water, realizing the transfer of charge.

[0052] The positive electrode plate 404, the membrane electrode 405, and the negative electrode plate 403 are all rectangular. When observed along the stacking direction of the two, the edges of the positive electrode plate 404 and the negative electrode plate 403 are aligned with each other. At both ends of the positive electrode plate 404, the membrane electrode 405, and the negative electrode plate 403 along the length direction, a first air outlet 406 and a first hydrogen inlet 408 are provided at one end, and a first hydrogen outlet 409 and a first air inlet 407 are provided at the other end. The first air outlet 406 and the first air inlet 407 are located on a diagonal of the rectangle, and the first hydrogen inlet 408 and the first hydrogen outlet 409 are located on the other diagonal of the rectangle. The two ends of the first ventilation circuit are respectively connected to the first air outlet 406 and the first air inlet 407, and the two ends of the second ventilation circuit are respectively connected to the first hydrogen inlet 408 and the first hydrogen outlet 409. In the stacking direction of multiple bipolar plates 4, the first air outlet 406, the first air inlet 407, the first hydrogen inlet 408, and the first hydrogen outlet 409 are respectively aligned, forming four channels. For the channels corresponding to the first air inlet 407 and the first hydrogen inlet 408, only by inputting the corresponding gas at one end of the channel, the gas will enter each layer of the bipolar plate 4 simultaneously.

[0053] Preferably, a plastic frame 401 is arranged on the side of the negative plate 403 facing away from the membrane electrode 405, and the plastic frame 401 can be fixed on the negative plate 403 by glue. A placing groove is formed on the plastic frame 401, the placing groove is hollowed out in the stacking direction, and the placing groove has at least one. A metal sponge 402 is placed in the placing groove, and the depth of the metal sponge 402 is equivalent to the depth of the placing groove. The metal sponge 402 can ventilate and dissipate heat on one hand, and can contact the first conductive plate 411 on another bipolar plate 4 on the other hand, so as to realize the communication of the positive and negative electrodes of the two adjacent bipolar plates 4.

[0054] A second conductive plate 412 and a third conductive plate 413 are arranged at two ends of the bipolar plate group composed of a plurality of bipolar plates 403 respectively. The second conductive plate 412 is located between the bipolar plate group and the upper cover plate 1, and the third conductive plate 413 is located between the lower cover plate 2 and the bipolar plate group. A second air outlet 302, a first water outlet 304 and a second air inlet 303 are arranged on the third conductive plate 413. The second air outlet 302 is aligned with the first air inlet 407, and the air from the second air outlet 302 enters the first air inlet 407. The first water outlet 304 is aligned with the first hydrogen outlet 409, and the hydrogen from the first hydrogen outlet 409 carries a certain amount of water, and part of the water drops from the first water outlet 304. The second air inlet 303 is aligned with the first air outlet 406, and the used air from the first air outlet 406 enters the second air inlet 303.

[0055] The electric pile further comprises a humidifying assembly 3 for humidifying the air entering the first air inlet 407 from the second air outlet 302. The humidifying assembly 3 is located between the third conductive plate 413 and the lower cover plate 2. The humidifying assembly 3 comprises at least one set of humidifying layers, which comprises a first humidifying layer 305, a diaphragm and a second humidifying layer 309 stacked together in sequence. The first humidifying layer 305 is provided with a first flow-through space 314, a third air outlet 311, a second water outlet 317, a sixth air outlet 320, a fifth air inlet 318 and a third air inlet 310. The third air inlet 310 is in communication with the first flow-through space 314, and the third air outlet 311 is also in communication with the first flow-through space 314. The air from the outside enters the first flow-through space 314 from the third air inlet 310 and goes out from the third air outlet 311. The second water outlet 317, the fifth air inlet 318 and the sixth air outlet 320 are not in communication with the first flow-through space 314. The third air outlet 311 is aligned with and in communication with the first air inlet 407, the second water outlet 317 is aligned with and in communication with the first water outlet 304, and the fifth air inlet 318 is aligned with and in communication with the second air inlet 303. The first flow-through space 314 is provided with a first partition plate 307. The first partition plate 307 is provided with a notch. The notches on the two first partition plates 307 are located at opposite positions to increase the flow time of the air in the first flow-through space 314.

[0056] The second humidifying layer 309 is provided with a second flow-through space 315, a sixth air inlet 319, a fourth air inlet 312, a fourth air outlet 313, a third water outlet 318 and a fifth air outlet 316. The fourth air inlet 312 is in communication with the second flow-through space 315, and the second flow-through space 315 is in communication with the fourth air outlet 313. The fourth air inlet 312 is aligned with and in communication with the second air inlet 303 and the first air outlet 406. The used air goes out from the first air outlet 406, enters the second flow-through space 315 through the second air inlet 303 and the fourth air inlet 312, and carries moisture. The moisture in the used air enters the first flow-through space 314 through the diaphragm after the used air enters the second flow-through space 315, and humidifies the air from the outside. The humidified air enters the first air circuit, and the moisture in the air in the first air circuit seeps into the membrane electrode 405. The moisture in the membrane electrode 405 helps the H +The air in the first air passage 405 reacts with oxygen in the air through the membrane electrode 405. The used air is finally discharged through the fourth air outlet 313. The third water outlet 318 is aligned with the first water outlet 304 and the first hydrogen outlet 409. The hydrogen in the second air passage entering the first hydrogen outlet 409 will carry some water, which will enter the third water outlet 318 under the action of its own gravity. The fifth air outlet 316 is aligned with and communicates with the third air outlet 311. The fourth air inlet 312 is aligned with and communicates with the fifth air inlet 318. The sixth air inlet 319 is aligned with and communicates with the third air inlet 310. The fourth air outlet 313 is aligned with and communicates with the sixth air outlet 310.

[0057] The upper cover plate 1 includes a cover body 101, a solenoid valve 103 and a pressure regulating valve 104. A hydrogen inlet hole 102, a first mounting hole 105 and a second mounting hole 106 are arranged on the cover body 101. The end of the hydrogen inlet hole 102 is provided with a pipe joint. The first mounting hole 105 is used to mount the solenoid valve 103. The second mounting hole 106 is used to mount the pressure regulating valve 104. The hydrogen inlet hole 102 communicates with the first mounting hole 105 and the second mounting hole 106. The solenoid valve 103 can control the opening and closing of the hydrogen inlet hole 102. The pressure regulating valve 104 is used to control the gas pressure of hydrogen.

[0058] A hydrogen outlet hole (not shown) is also arranged on the upper cover plate 1. The hydrogen outlet hole is aligned with and communicates with the first hydrogen inlet 408. The hydrogen from the pressure regulating valve 104 enters the first hydrogen inlet 408 through the hydrogen outlet hole. A hydrogen return hole (not shown) is also arranged on the upper cover plate 1. The hydrogen return hole is aligned with and communicates with the first hydrogen outlet 409, and at the same time, the hydrogen return hole communicates with the hydrogen inlet hole 102, realizing the recycling of hydrogen. Corresponding holes are arranged on the second conductive plate 412 at positions corresponding to the hydrogen outlet hole and the hydrogen return hole to ensure the normal flow of hydrogen.

[0059] The lower cover plate 2 is provided with an eighth air inlet 205, a seventh air inlet 201, a sixth air outlet 202, a fourth water outlet 203, a drain outlet 204, and an air pump 206. The air pump 206 is mounted on the lower cover plate 2, and its air outlet is connected to the eighth air inlet 205. The eighth air inlet 205 is connected to the seventh air inlet 201. The seventh air inlet 201 is aligned with and connected to the sixth air inlet 319 in the stacking direction. The sixth air outlet 202 is aligned with and connected to the fourth air outlet 313 in the stacking direction. Used air is discharged through the fifth air outlet 316. The fourth water outlet 203 is aligned with and connected to the third water outlet 318 in the stacking direction. The drain outlet 204 is connected to the fourth water outlet 203. A drain valve (not shown) is provided on the lower cover plate 2 at the position corresponding to the drain outlet 204. Drainage can be achieved by controlling the opening and closing of the drain valve. Since the fourth water outlet 203 is connected to the first hydrogen outlet 409, a small amount of hydrogen will be discharged when the drain valve is opened.

[0060] Example 2

[0061] like Figures 17-21 As shown, in this embodiment, the structure of the bipolar plate differs from that in Embodiment 1, while other structures remain the same. The bipolar plate 5 in this embodiment includes a positive electrode 501, a membrane electrode, and a negative electrode 502 stacked sequentially. Viewed along the stacking direction, the bipolar plate 5 is rectangular. A first hydrogen inlet 503, a first air outlet 504, a first hydrogen outlet 506, and a first air inlet 505 are formed on the bipolar plate 5. Along the length of the rectangle, the first hydrogen inlet 503 and the first air inlet 504 are located at one end of the bipolar plate 5, and the first hydrogen outlet 506 and the first air inlet 505 are located at the other end of the bipolar plate 5. Furthermore, the first hydrogen inlet 503 and the first hydrogen outlet 506 are located on one diagonal of the rectangle, and the first air outlet 504 and the first air inlet 505 are located on the other diagonal of the rectangle.

[0062] The first hydrogen inlet 503, first air outlet 504, first hydrogen outlet 506, and first air inlet 505 penetrate the positive electrode plate 501, the membrane electrode, and the negative electrode plate 502. The positive electrode plate 501 includes a positive electrode outer frame 509, a positive electrode carbon plate 508 disposed within the positive electrode outer frame 509, and a positive electrode conductive plate 511 disposed on the side of the positive electrode outer frame 509 facing away from the membrane electrode. A positive electrode ventilation circuit is provided on the side of the positive electrode carbon plate 508 facing the membrane electrode. The positive electrode ventilation circuit is U-shaped, with one end connected to the first air inlet 505 and the other end connected to the first air outlet 504. The positive electrode conductive plate 511 is in contact with the positive electrode carbon plate 508 for conduction.

[0063] The negative electrode plate 502 includes a negative electrode outer frame 513, a negative electrode carbon plate 512 disposed within the negative electrode outer frame 513, and a negative electrode conductive plate 514 disposed on the side of the negative electrode outer frame 513 facing away from the membrane electrode. A negative electrode ventilation circuit is provided on the side of the negative electrode carbon plate 512 facing the membrane electrode. The negative electrode ventilation circuit is U-shaped, with one end connected to the first hydrogen inlet 503 and the other end connected to the first hydrogen outlet 506. The membrane electrode separates the positive electrode ventilation circuit and the negative electrode ventilation circuit. The negative electrode carbon plate 512 is in contact with the negative electrode conductive plate 514 for conductivity. Both the positive electrode outer frame 509 and the negative electrode outer frame 513 are made of plastic, which reduces the use of carbon materials and lowers costs.

[0064] Support frames 515 are respectively provided at both ends along the length direction on the side of the negative electrode conductive plate 514 away from the membrane electrode. A placement groove is formed between the two support frames 515, and a metal sponge 516 is placed in the placement groove. The metal sponge 516 facilitates heat dissipation and conducts electricity. In two adjacent bipolar plates 5, the positive electrode conductive plate 511 of the previous bipolar plate 5 is in contact with the metal sponge 516 of the next bipolar plate 5, realizing the conduction between the positive and negative electrodes of the two adjacent bipolar plates 5.

[0065] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A hydrogen fuel cell stack, characterized by, The application relates to a fuel cell, which comprises: an upper cover plate; a lower cover plate; a plurality of bipolar plates arranged between the upper cover plate and the lower cover plate, the plurality of bipolar plates being stacked together, each bipolar plate having a negative side and a positive side, in adjacent bipolar plates, the positive side or the negative side of one bipolar plate being in contact with the negative side or the positive side of the other bipolar plate, and each bipolar plate comprising a positive plate, a membrane electrode and a negative plate stacked in sequence along the stacking direction of the plurality of bipolar plates; when viewed along the stacking direction, the bipolar plate is rectangular, at two ends of the bipolar plate along the length direction of the rectangle, one end is provided with a first air outlet and a first hydrogen inlet, and the other end is provided with a first hydrogen outlet and a first air inlet, the first air outlet and the first air inlet are arranged on one diagonal line of the rectangle, and the first hydrogen inlet and the first hydrogen outlet are arranged on the other diagonal line of the rectangle; a first hydrogen circulation loop and a second hydrogen circulation loop are arranged on the mutually facing sides of the positive plate and the negative plate, the first hydrogen circulation loop and the second hydrogen circulation loop are both "U"-shaped, one end of the first hydrogen circulation loop is in communication with the first air outlet, and the other end is in communication with the first air inlet, one end of the second hydrogen circulation loop is in communication with the first hydrogen outlet, and the other end is in communication with the first hydrogen inlet; the positive plate and the negative plate are at least partially made of carbon plates, and the first hydrogen circulation loop and the second hydrogen circulation loop are arranged on the corresponding carbon plates; a first conductive plate is arranged on the side of the positive plate away from the membrane electrode; a plastic frame is arranged on the side of the negative plate away from the membrane electrode, a placing groove is formed on the plastic frame, the placing groove is hollow in the stacking direction, the placing groove has at least one, and a metal sponge is arranged in the placing groove, the thickness of the metal sponge is equal to or slightly greater than the depth of the placing groove, and one side of the metal sponge is in contact with the negative plate; a second conductive plate and a third conductive plate are arranged at two ends of a bipolar plate group formed by the plurality of bipolar plates, the second conductive plate is arranged between the bipolar plate group and the upper cover plate, and the third conductive plate is arranged between the lower cover plate and the bipolar plate group; a second air outlet, a first water outlet and a second air inlet are arranged on the third conductive plate, and the second air outlet is aligned with and in communication with the first air inlet, the first water outlet is aligned with and in communication with the first hydrogen outlet, and the second air inlet is aligned with and in communication with the first hydrogen outlet.

2. A hydrogen fuel cell stack according to claim 1, wherein The application further relates to a humidifying assembly for humidifying air entering the first air inlet from the second air outlet, the humidifying assembly being arranged between the third conductive plate and the lower cover plate, and comprising at least one humidifying layer, the humidifying layer comprising a first humidifying layer, a diaphragm and a second humidifying layer stacked in sequence, the diaphragm separating the first humidifying layer from the second humidifying layer, used air of the bipolar plate being able to enter the second humidifying layer, external air being able to enter the first humidifying layer, and moisture in the second humidifying layer being able to enter the first humidifying layer through the diaphragm and humidify air in the first humidifying layer.

3. A hydrogen fuel cell stack according to claim 2, wherein The first humidifying layer is provided with a first flow-through space, a third air outlet, a second water outlet, a sixth air outlet, a fifth air inlet and a third air inlet. The third air inlet and the first flow-through space are in communication, and the third air outlet is also in communication with the first flow-through space. Air from the outside enters the first flow-through space through the third air inlet and exits through the third air outlet. The second water outlet is aligned with and in communication with the first water outlet, and the fifth air inlet is aligned with and in communication with the second air inlet.

4. A hydrogen fuel cell stack according to claim 3, wherein The first flow-through space is provided with a first partition plate. The first partition plate is provided with at least two first partition plates. The two first partition plates are parallel to each other. Each of the first partition plates is provided with a notch. The notches on the two first partition plates are arranged at opposite positions along the extension direction of the partition plate.

5. A hydrogen fuel cell stack according to claim 3, wherein The second humidifying layer is provided with a second flow-through space, a sixth air inlet, a fourth air inlet, a fourth air outlet, a third water outlet and a fifth air outlet. The fourth air inlet and the second flow-through space are in communication. The second flow-through space is in communication with the fourth air outlet. The fourth air outlet is in communication with the outside. In the stacking direction, the fourth air inlet is aligned with the second air inlet and the first air outlet. The third water outlet is aligned with the first water outlet and the first hydrogen outlet. The fifth air outlet is aligned with and in communication with the third air outlet. The fourth air inlet is aligned with and in communication with the fifth air inlet. The sixth air inlet is aligned with and in communication with the third air inlet. The fourth air outlet is aligned with and in communication with the sixth air outlet.

6. A hydrogen fuel cell stack according to claim 1, wherein The upper cover plate includes a cover body. A hydrogen inlet hole, a first mounting hole and a second mounting hole are arranged on the cover body. The outer end of the hydrogen inlet hole is provided with a pipe joint. The first mounting hole is used for mounting a solenoid valve. The second mounting hole is used for mounting a pressure regulating valve. The hydrogen inlet hole is in communication with the first mounting hole and the second mounting hole. The solenoid valve can control the opening and closing of the hydrogen inlet hole. The pressure regulating valve is used for controlling the gas pressure of hydrogen. The upper cover plate is also provided with a hydrogen outlet hole. The hydrogen outlet hole is aligned with and in communication with the first hydrogen inlet. Hydrogen from the pressure regulating valve enters the first hydrogen inlet through the hydrogen outlet hole. The upper cover plate is also provided with a hydrogen return hole. The hydrogen return hole is aligned with and in communication with the first hydrogen outlet. At the same time, the hydrogen return hole is in communication with the hydrogen inlet hole. And / or, The lower cover plate is provided with an eighth air inlet, a seventh air inlet, a sixth air outlet, a fourth water outlet, a drain port and an air pump. The air pump is arranged on the lower cover plate. The air outlet of the air pump is in communication with the eighth air inlet. The eighth air inlet is in communication with the seventh air inlet. In the stacking direction, the seventh air inlet is aligned with and in communication with the sixth air inlet. In the stacking direction, the sixth air outlet is aligned with and in communication with the fourth air outlet. Used air is discharged through the fifth air outlet. The fourth water outlet is aligned with and in communication with the third water outlet in the stacking direction. The drain port is in communication with the fourth water outlet. A drain valve is arranged on the lower cover plate at a position corresponding to the drain port. By controlling the opening and closing of the drain valve, drainage can be achieved.

7. A hydrogen fuel cell stack according to claim 1, wherein The positive electrode plate includes a positive electrode outer frame, a positive electrode carbon plate disposed within the positive electrode outer frame, and a positive electrode conductive plate disposed on a side of the positive electrode outer frame facing away from the membrane electrode. A positive electrode ventilation circuit is provided on a side of the positive electrode carbon plate facing the membrane electrode. The positive electrode ventilation circuit is in a "U" shape. One end of the positive electrode ventilation circuit is connected to a first air inlet, and the other end is connected to a first air outlet. The positive electrode conductive plate is in contact with the positive electrode carbon plate. The negative electrode plate includes a negative electrode outer frame, a negative electrode carbon plate disposed within the negative electrode outer frame, and a negative electrode conductive plate disposed on a side of the negative electrode outer frame facing away from the membrane electrode. A negative electrode ventilation circuit is provided on a side of the negative electrode carbon plate facing the membrane electrode. The negative electrode ventilation circuit is in a "U" shape. One end of the negative electrode ventilation circuit is connected to a first hydrogen inlet, and the other end is connected to a first hydrogen outlet. The membrane electrode separates the positive electrode ventilation circuit and the negative electrode ventilation circuit. The negative electrode carbon plate is in contact with the negative electrode conductive plate. Both the positive electrode outer frame and the negative electrode outer frame are made of plastic. Support frames are respectively provided at two ends along the length direction on a side of the negative electrode conductive plate facing away from the membrane electrode. A placement groove is formed between the two support frames. A metal sponge is placed in the placement groove. For adjacent bipolar plates, the positive electrode conductive plate of the previous bipolar plate is in contact with the metal sponge of the next bipolar plate.

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