Hydrogen fuel cell stack

Abstract

The invention provides a hydrogen fuel cell stack. The hydrogen fuel cell stack comprises an upper cover plate; a lower cover plate; the bipolar plates are arranged between the upper cover plate and the lower cover plate, the bipolar plates are stacked together, one side of each bipolar plate is a negative electrode, the other side of each bipolar plate is a positive electrode, and in the adjacent bipolar plates, the positive electrode or the negative electrode of one bipolar plate is in contact with the negative electrode or the positive electrode of the other bipolar plate; each bipolar plate comprises a positive plate, a membrane electrode and a negative plate which are sequentially stacked along the stacking direction of the plurality of bipolar plates; a first ventilation loop and a second ventilation loop are arranged on the sides, facing each other, of the positive plate and the negative plate respectively, the first ventilation loop and the second ventilation loop are bent in a shape like a Chinese character'ji ', one end of the first ventilation loop is communicated with the first air outlet, and the other end of the first ventilation loop is communicated with the first air inlet; one end of the second ventilation loop is communicated with the first hydrogen outlet, and the other end is communicated with the first hydrogen inlet.

Description

Technical Field

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

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

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

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

[0005] In order to achieve the above objectives, the technical solution adopted by the present invention is: a hydrogen fuel cell stack, comprising:

[0006] Upper cover;

[0007] Lower cover;

[0008] Multiple bipolar plates, the multiple bipolar plates are arranged between the upper cover plate and the lower cover plate, the multiple bipolar plates are stacked together, one side of each bipolar plate is a negative electrode and the other side is a positive electrode, and in adjacent bipolar plates, the positive electrode or negative electrode of one bipolar plate contacts the negative electrode or positive electrode of another 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 multiple bipolar plates;

[0009] When observed along the stacking direction, the bipolar plate is rectangular, and at both 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 a diagonal line of the rectangle, and the first hydrogen inlet and the first hydrogen outlet are arranged on another diagonal line of the rectangle;

[0010] A first ventilation circuit and a second ventilation circuit are respectively arranged on the mutually facing sides of the positive plate and the negative plate, the first ventilation circuit and the second ventilation circuit are both bent in a "J" 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 electrode plate and the negative electrode plate are at least partially made of carbon plates, and the first ventilation circuit and the second ventilation circuit are arranged on the corresponding carbon plates.

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

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

[0014] Preferably, a second conductive plate and a third conductive plate are respectively arranged at both ends of a 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 connected to the first air inlet, the first water outlet is aligned with and connected to the first hydrogen outlet, and the second air inlet is aligned with and connected to the first air outlet.

[0015] Preferably, a humidifying component is also included for humidifying the air entering the first air inlet from the second air outlet, and the humidifying component is located between the third conductive plate and the lower cover plate. The humidifying component includes at least one group of humidifying layers, and 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 air used through the bipolar plate can enter the second humidifying layer, and the outside air can enter the first humidifying layer. The moisture in the second humidifying layer can pass through the diaphragm into the first humidifying layer and humidify the air in the first humidifying layer.

[0016] Preferably, a first circulation space, a third air outlet, a second water outlet, a sixth air outlet, a fifth air inlet and a third air inlet are provided on the first humidification layer, the third air inlet is connected to the first circulation space, the third air outlet is also connected to the first circulation space, the outside air enters the first circulation space from the third air inlet and goes out from the third air outlet; the second water outlet is aligned with and connected to the first water outlet, and the fifth air inlet is aligned with and connected to the second air inlet.

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

[0018] Preferably, the second humidifying layer is provided with a second circulation 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 is connected to the second circulation space, and the second circulation space is also connected to the fourth air outlet, and the fourth air outlet is connected to 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 connected to the third air outlet, the fourth air inlet is aligned with and connected to the fifth air inlet, the sixth air inlet is aligned with and connected to the third air inlet, and the fourth air outlet is aligned with and connected to the sixth air outlet.

[0019] Preferably, the upper cover plate comprises a cover body, on which a hydrogen inlet hole, a first mounting hole and a second mounting hole are arranged, a pipe joint is arranged at the outer end of the hydrogen inlet hole, the first mounting hole is used to install a solenoid valve, the second mounting hole is used to install a pressure regulating valve, the hydrogen inlet hole is communicated with the first mounting hole and the second mounting hole, the solenoid valve can control the switch of the hydrogen inlet hole, and the pressure regulating valve is used to control the gas pressure of hydrogen;

[0020] A hydrogen outlet hole is also provided on the upper cover plate, the hydrogen outlet hole is aligned with and connected to the first hydrogen inlet, and the hydrogen coming out of the pressure regulating valve enters the first hydrogen inlet through the hydrogen outlet hole; a hydrogen return hole is also provided on the upper cover plate, the hydrogen return hole is aligned with and connected to the first hydrogen outlet, and the hydrogen return hole is connected to the hydrogen inlet hole;

[0021] and / or,

[0022] An eighth air inlet, a seventh air inlet, a sixth air outlet, a fourth water outlet, a drain and an air pump are provided on the lower cover plate. The air pump is provided on the lower cover plate and the air outlet of the air pump is communicated with the eighth air inlet, the eighth air inlet is communicated with the seventh air inlet, the seventh air inlet is aligned with and communicated with the sixth air inlet in the stacking direction, the sixth air outlet is aligned with and communicated with the fourth air outlet in the stacking direction, and used air is discharged through the fifth air outlet; the fourth water outlet is aligned with and communicated with the third water outlet in the stacking direction, the drain is communicated with the fourth water outlet, and a drain valve is provided at a position corresponding to the drain outlet on the lower cover plate, and drainage can be achieved by controlling the switch of the drain valve.

[0023] Preferably, the positive electrode plate comprises 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, and a positive electrode ventilation loop is arranged on the side of the positive electrode carbon plate facing the membrane electrode, and the positive electrode ventilation loop is in a "J" shape, one end of the positive electrode ventilation loop is connected to the first air inlet, and the other end is connected to the first air outlet, and the positive electrode conductive plate is in contact with the positive electrode carbon plate;

[0024] The negative electrode plate comprises a negative electrode outer frame, a negative electrode carbon plate arranged in the negative electrode outer frame, and a negative electrode conductive plate arranged on the side of the negative electrode outer frame away from the membrane electrode. A negative electrode ventilation circuit is arranged on the side of the negative electrode carbon plate facing the membrane electrode. The negative electrode ventilation circuit is in a "J" shape. One end of the negative electrode ventilation circuit is connected to the first hydrogen inlet, and the other end is connected to the first hydrogen outlet. The membrane electrode separates the positive electrode ventilation circuit from the negative electrode ventilation circuit. The negative electrode carbon plate is in contact with the negative electrode conductive plate. The positive electrode outer frame and the negative electrode outer frame are both made of plastic.

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

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

[0027] 1) The bipolar plate of the present invention uses metal sponge for heat dissipation, and the metal sponge is also used for electrical conduction, playing a dual role;

[0028] 2) The present invention provides two types of bipolar plates. When the size of the battery stack is small, a bipolar plate in which both the positive plate and the negative plate are carbon plates can be used. When the size of the battery stack is large, a bipolar plate in which both the positive plate and the negative plate are partially carbon plates can be used to reduce material costs.

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

[0030] 4) The present invention has a humidifying layer, which uses part of the moisture generated by the fuel cell stack reaction to humidify the new air. The humidified air helps the reaction of the fuel cell stack. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 and Figure 2 is a three-dimensional diagram of a battery stack according to the first embodiment of the present invention;

[0032] Figure 3 is a three-dimensional diagram of the bipolar plate of the first embodiment;

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

[0034] Figure 5 is a three-dimensional diagram of the bipolar plate of the first embodiment from another angle;

[0035] Figure 6 is a three-dimensional diagram of the bipolar plate of Example 1 without the metal sponge;

[0036] Figure 7 is a structural diagram of the carbon plate of Example 1;

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

[0038] Fig. 9 It is a structural diagram of the humidification component and the third conductive plate;

[0039] Fig.10 It is a structural diagram of the humidification component;

[0040] Fig.11 and Fig.12 It is a structural diagram of the first humidification layer;

[0041] Fig.13 and Fig.14 It is the structural diagram of the second humidification layer;

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

[0043] Fig.17 and Fig.18 is a structural diagram of a bipolar plate of Embodiment 2;

[0044] Fig.19 It is an enlarged view of point B;

[0045] Fig. 20 is a structural diagram of the bipolar plate of Example 2 without the positive conductive plate;

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

[0047] The following description is used to disclose the present invention so that those skilled in the art can implement the present invention. The preferred embodiments described below are only examples, and those skilled in the art may think of other obvious variations.

[0048] Embodiment 1

[0049] like Figure 1-16 As shown, a hydrogen fuel cell stack includes an upper cover plate 1, a lower cover plate 2 and a plurality of bipolar plates 4, wherein the plurality of bipolar plates 4 are arranged between the upper cover plate 1 and the lower cover plate 2, and the plurality of bipolar plates 4 are stacked, wherein one side of each bipolar plate 4 is a negative electrode and the other side is a positive electrode, and among adjacent bipolar plates 4, the positive electrode or negative electrode of one bipolar plate 4 is in contact with the negative electrode or positive electrode of another bipolar plate 4, that is, the plurality of bipolar plates 4 are connected in series.

[0050] Each bipolar plate 4 includes a positive plate 404, a membrane electrode 405 and a negative plate 403 stacked in sequence, wherein the positive plate 404 and the negative plate 403 are both made of carbon plates, and the membrane electrode 405 separates the positive plate 404 from the negative plate 403 to prevent the positive plate 404 from directly contacting the negative plate 403. A first conductive plate 411 is provided on the side of the positive plate 404 away from the membrane electrode 405 for conducting electricity, and the first conductive plate 411 is made of metal material to protect the carbon plate.

[0051] A ventilation circuit 410 is provided on the side of the positive plate 404 and the negative plate 403 facing each other. The ventilation circuit 410 is bent in a "J" shape to increase the circulation time of the gas in the ventilation circuit 410 and improve the utilization rate of hydrogen. For the convenience of description, the ventilation circuit 410 on the positive plate 404 is called the first ventilation circuit, and the ventilation circuit 410 on the negative plate 403 is called the second ventilation circuit. The ventilation circuits 410 on the positive plate 404 and the negative plate 403 can be separated by the membrane electrode 405, that is, the air and hydrogen passing through 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, thereby realizing the transfer of charge.

[0052] The positive plate 404, the membrane electrode 405 and the negative plate 403 are all rectangular, and when the two are observed in the stacking direction, the edges of the positive plate 404 and the negative plate 403 are aligned with each other. At both ends of the positive plate 404, the membrane electrode 405 and the negative plate 403 along the length direction, a first air outlet 406 and a first hydrogen inlet 408 are arranged at one end, and a first hydrogen outlet 409 and a first air inlet 407 are arranged at the other end. The first air outlet 406 and the first air inlet 407 are located on a diagonal line of the rectangle, and the first hydrogen inlet 408 and the first hydrogen outlet 409 are located on the other diagonal line 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 the 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 aligned respectively to form four channels, corresponding to the channels of the first air inlet 407 and the first hydrogen inlet 408. It is only necessary to input the corresponding gas at one end of the channel, and the gas will enter each layer of the bipolar plate 4 at the same time.

[0053] Preferably, a plastic frame 401 is provided on the side of the negative plate 403 away from the membrane electrode 405, and the plastic frame 401 can be fixed on the negative plate 403 by glue. A placement groove is formed on the plastic frame 401, and the placement groove is hollowed out in the stacking direction. There is at least one placement groove, and a metal sponge 402 is placed in the placement groove. The depth of the metal sponge 402 is equivalent to the depth of the placement groove. The metal sponge 402 can be ventilated and dissipated on the one hand, and can contact the first conductive plate 411 on the other bipolar plate 4 on the other hand, so as to realize the connection between 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 respectively arranged at both ends of the bipolar plate group composed of a plurality of bipolar plates 403. 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. The third conductive plate 413 is provided with a second air outlet 302, a first water outlet 304, and a second air inlet 303. The second air outlet 302 is aligned with the first air inlet 407, and the air coming out of the second air outlet 302 enters the first air inlet 407. The first water outlet 304 is aligned with the first hydrogen outlet 409. The hydrogen coming out of the first hydrogen outlet 409 will carry a certain amount of moisture, and part of the moisture will drip from the first water outlet 304. The second air inlet 303 is aligned with the first air outlet 406, and the used air coming out of the first air outlet 406 enters the second air inlet 303.

[0055] The stack also includes a humidifying component 3, which is used to humidify the air entering the first air inlet 407 from the second air outlet 302. The humidifying component 3 is located between the third conductive plate 413 and the lower cover plate 2. The humidifying component 3 includes at least one group of humidifying layers, which include 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 circulation 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 connected to the first circulation space 314, and the third air outlet 311 is also connected to the first circulation space 314. The outside air enters the first circulation 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 connected to the first circulation space 314. The third air outlet 311 is aligned with and communicated with the first air inlet 407, the second water outlet 317 is aligned with and communicated with the first water outlet 304, and the fifth air inlet 318 is aligned with and communicated with the second air inlet 303. A first baffle 307 is arranged in the first circulation space 314, and at least two first baffles 307 are arranged. The two first baffles 307 are parallel to each other and each first baffle 307 is provided with a notch. The notches on the two first baffles 307 are arranged at opposite positions to increase the flow time of air in the first circulation space 314.

[0056] The second humidification layer 309 is provided with a second circulation 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 communicated with the second circulation space 315, and the second circulation space 315 is also communicated with the fourth air outlet 313. The fourth air inlet 312 is aligned with and communicated with the second air inlet 303 and the first air outlet 406. After the used air comes out of the first air outlet 406, it enters the second circulation space 315 through the second air inlet 303 and the fourth air inlet 312. The used air will carry moisture. After the used air enters the second circulation space 315, the moisture in the used air will pass through the diaphragm and enter the first circulation space 314 to humidify the air entering from the outside. The humidified air enters the first ventilation circuit. The moisture in the air in the first ventilation circuit will penetrate into the membrane electrode 405. The moisture in the membrane electrode 405 will help H +Pass through the membrane electrode 405 and enter the first ventilation circuit to react with oxygen in the air. 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 entering the first hydrogen outlet 409 from the second ventilation circuit will carry a certain amount of moisture, and this moisture will enter the third water outlet 318 under the action of its own gravity. The fifth air outlet 316 is aligned with and connected to the third air outlet 311. The fourth air inlet 312 is aligned with and connected to the fifth air inlet 318. The sixth air inlet 319 is aligned with and connected to the third air inlet 310. The fourth air outlet 313 is aligned with and connected to 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 provided on the cover body 101. A pipe joint is provided at the end of the hydrogen inlet hole 102. The first mounting hole 105 is used to install the solenoid valve 103, and the second mounting hole 106 is used to install the pressure regulating valve 104. The hydrogen inlet hole 102 is connected with the first mounting hole 105 and the second mounting hole 106. The solenoid valve 103 can control the switch of the hydrogen inlet hole 102, and the pressure regulating valve 104 is used to control the gas pressure of hydrogen.

[0058] A hydrogen outlet hole (not shown) is also provided on the upper cover plate 1, and the hydrogen outlet hole is aligned with and connected to the first hydrogen inlet 408, and the hydrogen coming out of the pressure regulating valve 104 enters the first hydrogen inlet 408 through the hydrogen outlet hole. A hydrogen return hole (not shown) is also provided on the upper cover plate 1, and the hydrogen return hole is aligned with and connected to the first hydrogen outlet 409, and the hydrogen return hole is connected to the hydrogen inlet hole 102, so as to realize the recycling of hydrogen. Corresponding holes are provided on the second conductive plate 412 at positions corresponding to the hydrogen outlet hole and the hydrogen return hole to ensure the normal circulation 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 204 and an air pump 206. The air pump 206 is provided on the lower cover plate 2 and the air outlet of the air pump 206 is communicated with the eighth air inlet 205. The eighth air inlet 205 is communicated with the seventh air inlet 201. The seventh air inlet 201 is aligned with and communicated with the sixth air inlet 319 in the stacking direction. The sixth air outlet 202 is aligned with and communicated with the fourth air outlet 313 in the stacking direction. The used air is discharged through the fifth air outlet 316. The fourth water outlet 203 is aligned with and communicated with the third water outlet 318 in the stacking direction. The drain 204 is communicated with the fourth water outlet 203. A drain valve (not shown) is provided at a position corresponding to the drain 204 on the lower cover plate 2. Drainage can be achieved by controlling the switch 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] Embodiment 2

[0061] like Figure 17-21 As shown, in this embodiment, the structure of the bipolar plate is different from that in the first embodiment, and the other structures are the same. The bipolar plate 5 in this embodiment includes a positive plate 501, a membrane electrode, and a negative plate 502 stacked in sequence. When viewed along the stacking direction, the bipolar plate 5 is rectangular, and 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 direction of the rectangle, the first hydrogen inlet 503 and the first air inlet 504 are arranged at one end of the bipolar plate 5, and the first hydrogen outlet 506 and the first air inlet 505 are arranged at the other end of the bipolar plate 5, and the first hydrogen inlet 503 and the first hydrogen outlet 506 are arranged on a diagonal line of the rectangle, and the first air outlet 504 and the first air inlet 505 are arranged on the other diagonal line of the rectangle.

[0062] The first hydrogen inlet 503, the first air outlet 504, the first hydrogen outlet 506, and the first air inlet 505 penetrate the positive plate 501, the membrane electrode, and the negative plate 502. The positive plate 501 includes a positive outer frame 509, a positive carbon plate 508 disposed in the positive outer frame 509, and a positive conductive plate 511 disposed on the side of the positive outer frame 509 away from the membrane electrode. A positive ventilation loop is disposed on the side of the positive carbon plate 508 facing the membrane electrode. The positive ventilation loop is in the shape of a "J". One end of the positive ventilation loop is connected to the first air inlet 505, and the other end is connected to the first air outlet 504. The positive conductive plate 511 is in contact with the positive carbon plate 508 for conducting electricity.

[0063] The negative plate 502 includes a negative outer frame 513, a negative carbon plate 512 disposed in the negative outer frame 513, and a negative conductive plate 514 disposed on the side of the negative outer frame 513 away from the membrane electrode. A negative ventilation loop is disposed on the side of the negative carbon plate 512 facing the membrane electrode. The negative ventilation loop is in the shape of a "J". One end of the negative ventilation loop is connected to the first hydrogen inlet 503, and the other end is connected to the first hydrogen outlet 506. The membrane electrode separates the positive ventilation loop from the negative ventilation loop. The negative carbon plate 512 contacts the negative conductive plate 514 for conducting electricity. Both the positive outer frame 509 and the negative outer frame 513 are plastic, which can reduce the use of carbon materials and reduce costs.

[0064] Support frames 515 are respectively provided at both ends of the negative electrode conductive plate 514 along the length direction on the side away from the membrane electrode, and a placement groove is formed between the two support frames 515. A metal sponge 516 is placed in the placement groove. The metal sponge 516 is convenient for heat dissipation on the one hand and for conduction on the other hand. The positive conductive plate 511 of the first bipolar plate 5 of the adjacent two layers of bipolar plates 5 is in contact with the metal sponge 516 of the second bipolar plate 5, so that the positive and negative electrodes of the adjacent two layers of bipolar plates 5 are connected.

[0065] The above shows and describes 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 above embodiments and descriptions only describe the principles of the present invention. The present invention may be subject to various changes and improvements without departing from the spirit and scope of the present invention. These changes and improvements fall within the scope of the present invention. The scope of protection claimed by the present invention is defined by the attached claims and their equivalents.

Claims

1. A hydrogen fuel cell stack, characterized in that: include: Upper cover; Lower cover; Multiple bipolar plates, the multiple bipolar plates are arranged between the upper cover plate and the lower cover plate, the multiple bipolar plates are stacked together, one side of each bipolar plate is a negative electrode and the other side is a positive electrode, and in adjacent bipolar plates, the positive electrode or negative electrode of one bipolar plate contacts the negative electrode or positive electrode of another 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 multiple bipolar plates; When observed along the stacking direction, the bipolar plate is rectangular, and at both 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 a diagonal line of the rectangle, and the first hydrogen inlet and the first hydrogen outlet are arranged on another diagonal line of the rectangle; A first ventilation loop and a second ventilation loop are respectively arranged on the sides of the positive plate and the negative plate facing each other, the first ventilation loop and the second ventilation loop are both bent in a "J" shape, one end of the first ventilation loop is connected to the first air outlet, and the other end is connected to the first air inlet, one end of the second ventilation loop is connected to the first hydrogen outlet, and the other end is connected to the first hydrogen inlet; The positive electrode plate and the negative electrode plate are at least partially made of carbon plates, and the first ventilation loop and the second ventilation loop are arranged on the corresponding carbon plates.

2. A hydrogen fuel cell stack according to claim 1, characterized in that: A first conductive plate is arranged on a side of the positive electrode plate that is away from the membrane electrode.

3. A hydrogen fuel cell stack according to claim 2, characterized in that: A plastic frame is arranged on the side of the negative electrode plate facing away from the membrane electrode, and a placement groove is formed on the plastic frame. The placement groove is hollowed out in the stacking direction. There is at least one placement groove, and a metal sponge is placed in the placement groove. The thickness of the metal sponge is equal to or slightly greater than the depth of the placement groove, and one side of the metal sponge is in contact with the negative electrode plate.

4. A hydrogen fuel cell stack according to claim 3, characterized in that: A second conductive plate and a third conductive plate are respectively arranged at both ends of a bipolar plate group composed of a plurality of bipolar plates, wherein 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 connected to the first air inlet, the first water outlet is aligned with and connected to the first hydrogen outlet, and the second air inlet is aligned with and connected to the first air outlet.

5. A hydrogen fuel cell stack according to claim 4, characterized in that: It also includes a humidifying component for humidifying the air entering the first air inlet from the second air outlet, the humidifying component is located between the third conductive plate and the lower cover plate, the humidifying component includes at least one group 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 air used through the bipolar plate can enter the second humidifying layer, the outside air can enter the first humidifying layer, the moisture in the second humidifying layer can pass through the diaphragm into the first humidifying layer and humidify the air in the first humidifying layer.

6. A hydrogen fuel cell stack according to claim 5, characterized in that: The first humidification layer is provided with a first circulation space, a third air outlet, a second water outlet, a sixth air outlet, a fifth air inlet, and a third air inlet, wherein the third air inlet is connected to the first circulation space, and the third air outlet is also connected to the first circulation space, and the outside air enters the first circulation space from the third air inlet and goes out from the third air outlet; The second water outlet is aligned with and communicated with the first water outlet, and the fifth air inlet is aligned with and communicated with the second air inlet.

7. A hydrogen fuel cell stack according to claim 6, characterized in that: A first partition is arranged in the first circulation space. There are at least two first partitions. The two first partitions are parallel to each other and each first partition is provided with a notch. The notches on the two first partitions are arranged at opposite positions along the extension direction of the partition.

8. A hydrogen fuel cell stack according to claim 6, characterized in that: The second humidifying layer is provided with a second circulation 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 is connected to the second circulation space, and the second circulation space is also connected to the fourth air outlet, and the fourth air outlet is connected to 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 connected to the third air outlet, the fourth air inlet is aligned with and connected to the fifth air inlet, the sixth air inlet is aligned with and connected to the third air inlet, and the fourth air outlet is aligned with and connected to the sixth air outlet.

9. A hydrogen fuel cell stack according to claim 1, characterized in that: The upper cover plate includes a cover body, on which a hydrogen inlet hole, a first mounting hole and a second mounting hole are arranged, a pipe joint is arranged at the outer end of the hydrogen inlet hole, the first mounting hole is used to install a solenoid valve, the second mounting hole is used to install a pressure regulating valve, the hydrogen inlet hole is connected with the first mounting hole and the second mounting hole, the solenoid valve can control the switch of the hydrogen inlet hole, and the pressure regulating valve is used to control the gas pressure of hydrogen; A hydrogen outlet hole is also provided on the upper cover plate, the hydrogen outlet hole is aligned with and connected to the first hydrogen inlet, and the hydrogen coming out of the pressure regulating valve enters the first hydrogen inlet through the hydrogen outlet hole; a hydrogen return hole is also provided on the upper cover plate, the hydrogen return hole is aligned with and connected to the first hydrogen outlet, and the hydrogen return hole is connected to the hydrogen inlet hole; and / or, An eighth air inlet, a seventh air inlet, a sixth air outlet, a fourth water outlet, a drain and an air pump are provided on the lower cover plate. The air pump is provided on the lower cover plate and the air outlet of the air pump is communicated with the eighth air inlet, the eighth air inlet is communicated with the seventh air inlet, the seventh air inlet is aligned with and communicated with the sixth air inlet in the stacking direction, the sixth air outlet is aligned with and communicated with the fourth air outlet in the stacking direction, and used air is discharged through the fifth air outlet; the fourth water outlet is aligned with and communicated with the third water outlet in the stacking direction, the drain is communicated with the fourth water outlet, and a drain valve is provided at a position corresponding to the drain outlet on the lower cover plate, and drainage can be achieved by controlling the switch of the drain valve.

10. A hydrogen fuel cell stack according to claim 1, characterized in that: The positive electrode plate comprises 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, a positive electrode ventilation loop is arranged on the side of the positive electrode carbon plate facing the membrane electrode, and the positive electrode ventilation loop is in a "J" shape, one end of the positive electrode ventilation loop is connected to the first air inlet, and the other end is connected to the first air outlet, and the positive electrode conductive plate is in contact with the positive electrode carbon plate; The negative electrode plate comprises a negative electrode outer frame, a negative electrode carbon plate arranged in the negative electrode outer frame, and a negative electrode conductive plate arranged on the side of the negative electrode outer frame away from the membrane electrode, a negative electrode ventilation circuit is arranged on the side of the negative electrode carbon plate facing the membrane electrode, and the negative electrode ventilation circuit is in a "J" shape, one end of the negative electrode ventilation circuit is connected to the first hydrogen inlet, and the other end is connected to the 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, and the positive electrode outer frame and the negative electrode outer frame are both plastic; Support frames are respectively arranged at both ends along the length direction of the negative conductive plate on the side away from the membrane electrode, and a placement groove is formed between the two support frames. Metal sponge is placed in the placement groove. For two adjacent bipolar plates, the positive conductive plate of the front bipolar plate is in contact with the metal sponge of the rear bipolar plate.

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