Proton exchange membrane fuel cell bipolar plate, fuel cell and cell stack

Abstract

The utility model discloses a proton exchange membrane fuel cell bipolar plate, a fuel cell and a cell stack. The proton exchange membrane fuel cell bipolar plate comprises a bipolar plate monomer, two symmetrical Z-shaped folded edges integrally formed at the top end and the bottom end of the bipolar plate monomer, and parallel multi-gas-path runners arranged on the front wall and the back wall of the bipolar plate monomer, a hydrogen inlet, an oxygen outlet, a hydrogen outlet and an oxygen inlet which penetrate to the outside of the bipolar plate monomer are respectively formed in the corner positions of the surface of the bipolar plate monomer. According to the utility model, the bipolar plate monomer, the E-shaped end cover, the E-shaped bottom cover and the like which are matched with one another are arranged, the parallel multi-gas-path runners are designed on the front surface and the rear surface of the bipolar plate monomer, so that the uniform distribution of hydrogen and oxygen is ensured, and the E-shaped end cover and the E-shaped bottom cover effectively avoid the relative displacement between components; and the overall strength of the fuel cell stack is enhanced, so that the gas pressure, temperature change and mechanical stress in the fuel cell can be better resisted, and the condition of looseness or dislocation is prevented.

Description

Technical Field

[0001] This utility model relates to the field of fuel cell technology, specifically to proton exchange membrane fuel cell bipolar plates, fuel cells, and fuel cell stacks. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) consists of several key components: an electrolyte membrane, an anode, a cathode, a gas diffusion layer, and bipolar plates. The electrolyte membrane is the core of the fuel cell, acting as an isolation barrier for electrons and allowing protons to pass through. The anode and cathode are the inlets for hydrogen and oxygen, respectively. Catalysts (such as platinum) accelerate the ionization of hydrogen and the reduction of oxygen, producing protons, electrons, and water. The gas diffusion layer ensures uniform gas distribution across the electrode surfaces and directs current to the external circuitry. The bipolar plates connect multiple cells and are responsible for gas distribution, current conduction, and heat management. The PEMFC operates based on an electrochemical reaction where hydrogen decomposes into protons and electrons at the anode. Electrons form a current through the external circuitry, while protons migrate through the proton exchange membrane to the cathode. At the cathode, oxygen reacts with protons and electrons to produce water and release heat. This process continuously generates current and increases the voltage by connecting multiple cells in series.

[0003] The proton exchange membrane fuel cell bipolar plate, cell, and stack disclosed in application publication number CN110444785A include an anode plate and a cathode plate tightly pressed together. Grooves are formed on the surfaces of both the anode and cathode plates. Each anode and cathode plate has a fuel gas inlet, a fuel gas outlet, an oxidant gas inlet, an oxidant gas outlet, and a drain outlet. The fuel gas inlet and outlet on the anode plate are connected to the grooves on the anode plate. The oxidant gas inlet and outlet on the cathode plate are also connected to the grooves on the cathode plate. Each groove is filled with a porous three-dimensional substrate filler block. This filling of the grooves with porous three-dimensional substrate filler blocks creates a three-dimensional flow field structure within the grooves, ensuring stable gas diffusion. The diffusion is more uniform, ensuring smooth entry into the reaction zone, and there is no need to open flow channels inside the groove. However, the ends of the battery cells formed by stacking components such as bipolar plates, gas diffusion layers, and proton exchange membranes are still in a flexible state. That is, although these components generate a certain amount of physical pressure during operation, they do not have sufficient mechanical strength to maintain the structural integrity of the entire system. In particular, the proton exchange membrane is essentially a thin film material with low strength and is prone to deformation. Therefore, it requires several battery cells to be stacked to form a battery stack and supported by left and right end plates. For unsupported battery cells, the flexible state of their ends may cause them to deform or misalign during operation, especially during the supply of hydrogen and oxygen. Without endplate support, the ends of individual battery cells are subjected to physical forces generated during gas flow and electrochemical reactions. These forces can lead to unstable contact between the membrane, electrodes, and gas diffusion layer. Consequently, after prolonged use, the cells in the battery stack will experience frequent temperature and pressure fluctuations, which will cause fatigue of the end materials. Without endplate support, the mechanical strength of the battery cell ends is low. Under continuous stress cycles during long-term operation, the materials gradually suffer fatigue damage, which manifests as cracks, deformation, or structural loosening, thereby affecting the reliability and stability of the battery cells and the entire battery stack. Utility Model Content

[0004] The purpose of this invention is to provide a proton exchange membrane fuel cell bipolar plate, a fuel cell, and a fuel cell stack. A mountain-shaped end cap and a mountain-shaped bottom cap are installed on the top of each bipolar plate unit. The mountain-shaped end cap and bottom cap form a stable frame for the fuel cell, which consists of the bipolar plate unit, the gas diffusion layer, and the proton exchange membrane unit. Furthermore, when multiple fuel cells are assembled into a fuel cell stack, the mountain-shaped end cap and bottom cap, with the support of the left and right end plates, form an even more stable frame structure, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a proton exchange membrane fuel cell bipolar plate, comprising a bipolar plate unit, two symmetrical Z-shaped flanges integrally formed at the top and bottom of the bipolar plate unit, and parallel multi-channel flow paths arranged on the front and back walls of the bipolar plate unit. At the corners of the surface of the bipolar plate unit, hydrogen inlet, oxygen outlet, hydrogen outlet, and oxygen inlet are respectively provided, extending to the outside of the bipolar plate unit. The connecting line between the center points of the hydrogen inlet and hydrogen outlet and the connecting line between the center points of the oxygen inlet and oxygen outlet form an "X" shape. The hydrogen inlet and oxygen outlet are located at the inlet ends of the two parallel multi-channel flow paths, and the hydrogen outlet and oxygen outlet are located at the outlet ends of the two parallel multi-channel flow paths.

[0006] Preferably, a sealing groove is provided at the edge of the front wall and the back wall of the bipolar plate unit, and an inward protrusion near the center point of the bipolar plate unit is provided around the sealing groove. A sealing ring is embedded in the sealing groove, and the hydrogen inlet, oxygen inlet, hydrogen outlet, oxygen outlet and parallel multi-gas flow channel are located inside the sealing groove.

[0007] Preferably, one of the parallel multi-channel flow paths includes an upper-mounted split-flow inlet channel disposed at one end of the front wall of the bipolar plate unit, a plurality of equally spaced S-shaped channels connected at the bottom end of the upper-mounted split-flow inlet channel, and a lower-mounted collecting exhaust channel disposed at the other end of the front wall of the bipolar plate unit. The bottom end of the S-shaped channel is connected to the top end of the lower-mounted collecting exhaust channel. A bent channel is disposed between two adjacent S-shaped channels to connect the upper-mounted split-flow inlet channel and the lower-mounted collecting exhaust channel. The hydrogen inlet is connected to one end of the upper-mounted split-flow inlet channel, and the hydrogen outlet is connected to one end of the lower-mounted collecting exhaust channel.

[0008] This utility model also includes a proton exchange membrane fuel cell, including a proton exchange membrane fuel cell bipolar plate as described in any one of the above descriptions. The top and bottom of the bipolar plate unit are respectively provided with a mountain-shaped end cap and a mountain-shaped bottom cap. Both sides of the top of the mountain-shaped end cap and the mountain-shaped bottom cap are provided with rectangular hollow portions through which Z-shaped folds pass.

[0009] Preferably, on the outer wall of the bipolar plate unit near the vertical center reference plane of the mountain-shaped end cap and the mountain-shaped bottom cap, a gas diffusion layer one, a proton exchange membrane unit, a gas diffusion layer two, and a right bipolar plate are stacked in sequence, and the right bipolar plate and the bipolar plate unit have the same structural composition.

[0010] Preferably, the inside of the mountain-shaped end cap and the mountain-shaped bottom cap are provided with left plate grooves and right plate grooves on both sides for embedding the bipolar plate unit and the end of the right bipolar plate, and the inside of the mountain-shaped end cap and the mountain-shaped bottom cap between the left plate groove and the right plate groove is provided with a ridge plate.

[0011] Preferably, the left and right sides inside the spine plate are respectively provided with a left slot and a right slot, and the left and right slots are for the ends of the gas diffusion layer one and the gas diffusion layer two to be inserted.

[0012] Preferably, both ends of the surface of the mountain-shaped end cap and the mountain-shaped bottom cap are provided with column holes.

[0013] This utility model also includes a proton exchange membrane fuel cell stack, comprising multiple proton exchange membrane fuel cells arranged side by side as described above. On one side of the outermost mountain-shaped end cap and the mountain-shaped bottom cap, there is a T-bolt concentric with the column hole. One end of the T-bolt extends through to the outside of the mountain-shaped end cap and the mountain-shaped bottom cap and is fitted with a locking nut.

[0014] Preferably, two symmetrical locking pins are installed on one outer wall of the mountain-shaped end cap and the mountain-shaped bottom cap, and the mountain-shaped end cap and the mountain-shaped bottom cap are made of rubber components.

[0015] Compared with existing technologies, the beneficial effects of this utility model are as follows: The proton exchange membrane fuel cell bipolar plate, fuel cell, and stack are constructed with a structure incorporating bipolar plate units, mountain-shaped end caps, and mountain-shaped bottom caps. The bipolar plate units, through a front-to-back design with parallel multi-channel gas flow, ensure uniform distribution of hydrogen and oxygen, preventing gas leakage and improving battery efficiency and stability. Within each unit, the independent flow channel design of the bipolar plate ensures smooth gas flow, promoting efficient electrochemical reactions. The mountain-shaped end caps and bottom caps provide structural stability, and their unique geometry allows for a good fit with the various parts of the unit, effectively preventing relative displacement between components and enhancing the overall strength of the fuel cell stack. This better resists internal gas pressure, temperature changes, and mechanical stress, preventing loosening. In the event of misalignment, the end caps and bottom caps extend the battery's lifespan. Secondly, their structural design provides uniform and stable clamping force during fuel cell stack assembly. Due to the large contact area on the contact surfaces, the geometry of the end caps and bottom caps creates a more uniform clamping force distribution among the individual fuel cell cells, preventing damage to the membrane electrode assembly caused by excessive clamping at a single point. This design also ensures proper contact and tightness between the gas diffusion layer and the proton exchange membrane, further improving the overall sealing of the battery, preventing hydrogen and oxygen leakage, and increasing fuel cell efficiency. Finally, the robust frame structure reduces wear and damage between cells, preventing performance degradation due to component misalignment or damage. Furthermore, because the end caps and bottom caps provide uniform clamping force and better gas distribution, each cell in the fuel cell stack can operate under optimal conditions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the main structure of a single bipolar plate of this utility model;

[0017] Figure 2 This is a schematic diagram of the three-dimensional structure of the bipolar plate unit of this utility model. Figure 1 ;

[0018] Figure 3 This is a schematic diagram of the three-dimensional structure of the bipolar plate unit of this utility model. Figure 2 ;

[0019] Figure 4 This is a side view exploded structural diagram of the proton exchange membrane fuel cell of this utility model;

[0020] Figure 5 This is a three-dimensional exploded structural diagram of the proton exchange membrane fuel cell of this utility model;

[0021] Figure 6This is a schematic diagram of the three-dimensional cross-sectional structure of the mountain-shaped end cap of this utility model. Figure 1 ;

[0022] Figure 7 This utility model Figure 6 Enlarged structural diagram at point A in the middle;

[0023] Figure 8 This is a schematic diagram of the three-dimensional structure of the mountain-shaped end cap of this utility model. Figure 2 .

[0024] Figure 9 This is a three-dimensional structural diagram of the proton exchange membrane fuel cell stack of this utility model.

[0025] In the diagram: 1. Bipolar plate unit; 2. Sealing groove; 201. Inner protrusion; 3. Z-shaped fold; 4. Hydrogen inlet; 5. Hydrogen outlet; 6. Oxygen inlet; 7. Oxygen outlet; 8. Parallel multi-channel flow path; 801. Upper-positioned split-flow inlet channel; 802. Lower-positioned combined-flow exhaust channel; 803. S-shaped channel; 804. Bent channel; 9. Mountain-shaped end cap; 901. Column hole; 902. Locking pin; 903. Left plate slot; 904. Right plate slot; 905. Ridge plate; 9051. Left slot; 9052. Right slot; 10. Mountain-shaped bottom cap; 11. Gas diffusion layer one; 12. Proton exchange membrane unit; 13. Gas diffusion layer two; 14. Right bipolar plate; 15. Sealing ring; 16. T-bolt; 17. Locking nut. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the scope of protection of the present utility model.

[0027] Example 1, by Figure 1 , Figure 2 as well as Figure 3The present invention comprises a bipolar plate unit 1, two symmetrical Z-shaped flanges 3 integrally formed at the top and bottom of the bipolar plate unit 1, and parallel multi-channel flow paths 8 arranged on the front and back walls of the bipolar plate unit 1. At the corners of the surface of the bipolar plate unit 1, hydrogen inlet 4, oxygen outlet 7, hydrogen outlet 5, and oxygen inlet 6 are respectively provided, extending to the outside of the bipolar plate unit 1. The connecting line between the center points of hydrogen inlet 4 and hydrogen outlet 5 and the connecting line between the center points of oxygen inlet 6 and oxygen outlet 7 form an "X" shape. Hydrogen inlet 4 and oxygen inlet 6 are located at the inlet ends of the two parallel multi-channel flow paths 8, and hydrogen outlet 5 and oxygen outlet 7 are located at the outlet ends of the two parallel multi-channel flow paths 8. The parallel multi-channel flow paths 8 on the front and back of the bipolar plate unit 1 are used for hydrogen and oxygen flow, thereby distributing hydrogen and oxygen to the gas diffusion layer of the fuel cell to ensure uniform flow of the reactant gases and their reaction with the electrodes.

[0028] Example 2, based on Example 1, is... Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, sealing grooves 2 are provided at the edges of the front and back walls of the bipolar cell 1, and the sealing grooves 2 are surrounded by inward protrusions 201 near the center of the bipolar cell 1. A sealing ring 15 is embedded in the sealing groove 2. The hydrogen inlet 4, oxygen inlet 6, hydrogen outlet 5, oxygen outlet 7 and parallel multi-gas flow channels 8 are located inside the sealing groove 2. In order to ensure that hydrogen and oxygen do not leak during the flow, sealing grooves 2 are designed on the front and back surfaces of the bipolar cell 1. The sealing grooves 2, through cooperation with the gasket, make the bipolar cell 1, the gas diffusion layer or the proton exchange membrane tightly fitted to prevent gas leakage and ensure that the reaction gas reaches the electrode smoothly and participates in the electrochemical reaction.

[0029] One of the parallel multi-airflow channels 8 includes an upper-mounted split-flow inlet channel 801 located at one end of the front wall of the bipolar plate unit 1, several equally spaced S-shaped channels 803 connected at the bottom of the upper-mounted split-flow inlet channel 801, and a lower-mounted collecting exhaust channel 802 located at the other end of the front wall of the bipolar plate unit 1. The bottom of the S-shaped channels 803 and the top of the lower-mounted collecting exhaust channel 802 are interconnected. A bend in the flow path is provided between two adjacent S-shaped channels 803 to connect the upper-mounted split-flow inlet channel 801 and the lower-mounted collecting exhaust channel 802. Taking the parallel multi-channel flow channel 8 on the front of the bipolar plate unit 1 as an example, hydrogen enters the upper-positioned split-flow inlet channel 801 through the hydrogen inlet 4. The upper-positioned split-flow inlet channel 801 splits and distributes the hydrogen to each S-shaped channel 803 and the bent channel 804. At this time, the hydrogen flows downward and gradually reaches the lower-positioned collecting exhaust channel 802 where it is collected. Finally, it is discharged through the hydrogen outlet 5, thereby reducing the phenomenon of concentrated gas flow. This uniform gas distribution helps to ensure that the reactant gas reacts fully on the electrode surface.

[0030] The hydrogen inlet 4 is connected to one end of the upper-positioned split-flow inlet channel 801, and the hydrogen outlet 5 is connected to one end of the lower-positioned collection-flow exhaust channel 802. The S-shaped channel 803 and the bent channel 804 appropriately guide the direction of gas flow, so that the gas flow can complete the flow with a lower pressure loss, effectively alleviate areas where the gas flow speed is too fast or too slow, avoid local airflow blockage, and the larger contact area makes it easier for the gas to diffuse to the gas diffusion layer, thereby improving the efficiency of the electrochemical reaction. Especially under high load or high power output conditions, the effective distribution of gas can effectively avoid performance degradation.

[0031] like Figures 4 to 8 As shown, this utility model also includes a proton exchange membrane fuel cell, including the above-mentioned proton exchange membrane fuel cell bipolar plate. The top and bottom ends of the bipolar plate unit 1 are respectively provided with a mountain-shaped end cap 9 and a mountain-shaped bottom cap 10. Both sides of the top of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 are provided with rectangular hollow parts for the Z-shaped folded edge 3 to pass through. On the outer wall of the side of the bipolar plate unit 1 near the vertical center reference plane of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10, a gas diffusion layer 11, a proton exchange membrane unit 12, a gas diffusion layer 2 13 and a right bipolar plate 14 are stacked in sequence. The right bipolar plate 14 and the bipolar plate unit 1 have the same structural composition.

[0032] The inside of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 are provided with left plate grooves 903 and right plate grooves 904 for the ends of bipolar plate 1 and right bipolar plate 14 to be inserted. The inside of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 between the left plate grooves 903 and right plate grooves 904 is provided with a ridge plate 905. The left and right sides of the inside of the ridge plate 905 are respectively provided with a left slot 9051 and a right slot 9052. The left slot 9051 and the right slot 9052 are for the ends of gas diffusion layer 11 and gas diffusion layer 2 13 to be inserted.

[0033] Both ends of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 have post holes 901. When assembling the fuel cell using the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10, the workers position the bipolar plate cell 1 and the right bipolar plate 14 on the outermost side of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10, and ensure that the Z-shaped folds 3 at the top and bottom of the bipolar plate cell 1 extend to the outside of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10. Then, a sealing ring 15 is inserted into the sealing groove 2 of the bipolar plate cell 1. After the sealing ring 15 is inserted, the workers diffuse the gas. The top and bottom edges of layer 11 are inserted into the left slot 9051 of the ridge plate 905, while the proton exchange membrane monomer 12 is placed on the gas diffusion layer 11. The top and bottom edges of the gas diffusion layer 2 13 are inserted into the right slot 9052 of the ridge plate 905. Finally, the right bipolar plate 14 is installed into the right plate slot 904, thus completing the assembly of a fuel cell. After the assembly is completed, the staff carefully checks the alignment of each component, especially the adhesion between the bipolar plate and the gas diffusion layer and the proton exchange membrane, to ensure that there is no risk of gas leakage.

[0034] By using the frame structure design formed by the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10, these components can be effectively combined into a stable frame, and good support and clamping force can be provided for the assembly of multiple fuel cell cells in the battery stack.

[0035] like Figure 9 As shown, this utility model also includes a proton exchange membrane fuel cell stack, comprising multiple proton exchange membrane fuel cells arranged side by side. A T-bolt 16 concentric with the column hole 901 is provided on one outer wall of the outermost mountain-shaped end cap 9 and the mountain-shaped bottom cap 10. One end of the T-bolt 16 extends through to the outside of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 and is fitted with a locking nut 17. Two symmetrical locking pins 902 are installed on one outer wall of the mountain-shaped end cap 9 and the mountain-shaped bottom cap 10. The mountain-shaped end cap 9 and the mountain-shaped bottom cap 10 are made of rubber to facilitate the T-bolt 16 and the locking nut 17 in tightening the fuel cell.

[0036] In the fuel cell stack, multiple bipolar plate cells 1 are connected in series. Current is conducted between each cell through the bipolar plates to ensure the current output of the entire fuel cell stack. At the same time, the bipolar plates provide uniform clamping force to ensure good contact between the gas diffusion layer and the proton exchange membrane, thereby improving the efficiency and stability of the fuel cell.

[0037] When multiple fuel cells are stacked to form a fuel cell stack, the fuel cells consisting of the mountain-shaped end cap 9, the mountain-shaped bottom cap 10, the bipolar plate cell 1, the gas diffusion layer one 11, the proton exchange membrane cell 12, the gas diffusion layer two 13, and the right bipolar plate 14 are stacked. Adjacent mountain-shaped end caps 9 and mountain-shaped bottom caps 10 on the same horizontal direction are aligned and connected using locking pins 902. Then, workers insert T-bolts 16 through the locking pins 902 of the mountain-shaped end caps 9 and mountain-shaped bottom caps 10 until the end of the T-bolt 16 protrudes from the last mountain-shaped end cap 9. On the outside of the mountain-shaped bottom cover 10, a locking nut 17 is installed at the end of the T-bolt 16. The locking nut 17 continuously tightens the fuel cell. Through the tensioning action of the T-bolt 16 and the locking nut 17, loosening caused by pressure changes during stacking can be effectively prevented, ensuring that the entire stack will not deform or become structurally unstable, thereby improving the overall stability of the battery stack. Furthermore, by applying pressure evenly, the T-bolt 16 and the locking nut 17 ensure that the contact surfaces of each fuel cell are fully in contact and sealed, thereby ensuring that hydrogen and oxygen do not leak between the cells.

[0038] In this embodiment, the bipolar plate cell 1 is located between adjacent fuel cell cells, serving multiple functions including conductivity, gas distribution, and mechanical support. The parallel multi-channel flow 8 on the front and back of the bipolar plate cell 1 is used for hydrogen and oxygen flow, distributing hydrogen and oxygen to the gas diffusion layer of the fuel cell to ensure uniform flow of the reactant gases and their reaction with the electrodes. The parallel multi-channel flow 8 on the front and back of the bipolar plate cell 1 are independent to prevent hydrogen and oxygen from mixing. Each parallel multi-channel flow 8 ensures uniform gas distribution throughout the gas diffusion layer, avoiding decreased battery efficiency due to uneven or poor local gas flow. The hydrogen flow channel is located on one side of the bipolar plate cell 1 to guide hydrogen into the anode portion of the battery, while the oxygen flow channel is located on the other side of the bipolar plate cell 1 to guide oxygen into the cathode portion of the battery. Hydrogen flows through… Hydrogen gas enters through inlet 4 into parallel multi-channel flow 8 and diffuses downwards until it reaches outlet 5 for discharge. Oxygen gas enters through inlet 6 into another parallel multi-channel flow 8 and diffuses downwards until it reaches outlet 7 for discharge. During operation, hydrogen gas enters bipolar cell 1 through inlet 4 and flows along the hydrogen channel to the anode. Here, hydrogen reacts with hydrogen ions on the proton exchange membrane, releasing electrons and generating current. Oxygen gas enters bipolar cell 1 through inlet 6 and flows along the oxygen channel to the cathode. At the cathode, oxygen reacts with hydrogen ions and electrons to generate water and release heat. The parallel multi-channel flow 8 ensures that the hydrogen and oxygen channels are independently configured, avoiding direct contact between hydrogen and oxygen, preventing mixing and short circuits, ensuring uniform gas distribution within each fuel cell cell, and effectively improving battery efficiency.

[0039] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0040] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A proton exchange membrane fuel cell bipolar plate characterized by: The bipolar plate monomer (1) includes two symmetrical Z-shaped folded edges (3) integrally formed at the top and bottom of the bipolar plate monomer (1), and parallel multi-gas path flow channels (8) arranged on the front and back walls of the bipolar plate monomer (1). The hydrogen inlet (4), oxygen outlet (7), hydrogen outlet (5), and oxygen inlet (6) are arranged at the corner positions of the surface of the bipolar plate monomer (1). The connection lines between the center points of the hydrogen inlet (4) and hydrogen outlet (5) and the connection lines between the center points of the oxygen inlet (6) and oxygen outlet (7) form an "X" shape. The hydrogen inlet (4) and oxygen inlet (6) are located at the inlet end of the parallel multi-gas path flow channels (8), and the hydrogen outlet (5) and oxygen outlet (7) are located at the outlet end of the parallel multi-gas path flow channels (8).

2. The proton exchange membrane fuel cell bipolar plate of claim 1, wherein: The front and back walls of the bipolar plate monomer (1) are provided with sealing grooves (2) at the edge positions, and the sealing grooves (2) are provided with inner protrusions (201) near the center points of the bipolar plate monomer (1). The sealing grooves (2) are embedded with sealing rings (15). The hydrogen inlet (4), oxygen inlet (6), hydrogen outlet (5), oxygen outlet (7), and parallel multi-gas path flow channels (8) are located on the inner side of the sealing grooves (2).

3. The proton exchange membrane fuel cell bipolar plate of claim 2, wherein: One of the parallel multi-gas path flow channels (8) includes an upper split-type inlet flow groove (801) arranged at one end of the front wall of the bipolar plate monomer (1), a plurality of equidistant S-shaped flow grooves (803) arranged at the bottom end of the upper split-type inlet flow groove (801), and a lower collection-type outlet flow groove (802) arranged at the other end of the front wall of the bipolar plate monomer (1). The S-shaped flow grooves (803) and the lower collection-type outlet flow groove (802) are in communication with each other. The adjacent two S-shaped flow grooves (803) are provided with a bending flow groove (804) for connecting the upper split-type inlet flow groove (801) and the lower collection-type outlet flow groove (802). The hydrogen inlet (4) and one end of the upper split-type inlet flow groove (801) are in communication with each other, and the hydrogen outlet (5) and one end of the lower collection-type outlet flow groove (802) are in communication with each other.

4. A proton exchange membrane fuel cell characterised in that: The proton exchange membrane fuel cell bipolar plate includes the bipolar plate monomer (1) of any one of claims 1-3. The top and bottom of the bipolar plate monomer (1) are respectively provided with a mountain-shaped end cover (9) and a mountain-shaped bottom cover (10). The two sides of the top of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) are provided with rectangular hollow parts for the Z-shaped folded edges (3) to pass through.

5. The proton exchange membrane fuel cell of claim 4, wherein: The bipolar plate monomer (1) is stacked with a gas diffusion layer one (11), a proton exchange membrane monomer (12), a gas diffusion layer two (13), and a right bipolar plate (14) on the outer wall of the side close to the vertical center reference surface of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10). The right bipolar plate (14) has the same structure as the bipolar plate monomer (1).

6. The proton exchange membrane fuel cell of claim 5, wherein: The left and right sides of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) are provided with left plate grooves (903) and right plate grooves (904) for embedding the end of the bipolar plate monomer (1) and the right bipolar plate (14).

7. The proton exchange membrane fuel cell of claim 6, wherein: The left and right sides of the ridge plate (905) are respectively provided with left insertion grooves (9051) and right insertion grooves (9052) for embedding the end of the gas diffusion layer one (11) and the gas diffusion layer two (13).

8. The proton exchange membrane fuel cell of claim 5, wherein: The two ends of the surface of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) are provided with column holes (901).

9. A proton exchange membrane fuel cell stack characterised in that: The proton exchange membrane fuel cell comprises a plurality of proton exchange membrane fuel cells arranged side by side, and the same outer wall of one side of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) is provided with a T-shaped bolt (16) concentric with the column hole (901), one end of the T-shaped bolt (16) penetrates to the outside of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) and is provided with a locking nut (17).

10. The proton exchange membrane fuel cell stack of claim 9, wherein: The outer wall of one side of the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) is provided with two symmetrical clamping pins (902), and the mountain-shaped end cover (9) and the mountain-shaped bottom cover (10) are made of rubber material.

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