A disc-shaped fuel cell bipolar plate and a fuel cell stack

Abstract

The present invention discloses a disc-shaped fuel cell bipolar plate and stack, belonging to the technical field of fuel cells. It includes a bipolar plate body, the plate body is funnel-shaped, the outer surface of the bipolar plate body is the anode surface, the inner surface of the bipolar plate body is the cathode surface, the anode surface is provided with a hydrogen guide area, a hydrogen distribution area and a hydrogen reaction area which are arranged in an annular manner and are interconnected from the small diameter end to the large diameter end, the hydrogen distribution area is provided with a number of oxygen inlet holes which penetrate the bipolar plate body, the hydrogen reaction area is located inside the edge of the anode surface, and the edge of the hydrogen reaction area close to the large diameter end of the bipolar plate body is provided with a number of hydrogen outlet holes which penetrate the bipolar plate body, and a number of cathode flow channel units are evenly distributed on the circumference of the cathode surface, and a number of the cathode flow channel units are interconnected with a number of the oxygen inlet holes. This technical solution is used to solve the problem of poor drainage effect of the plate set in the prior art.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells, and in particular relates to a disc-shaped fuel cell bipolar plate and a fuel cell stack. Background Art

[0002] The fuel cell stack is the core component of the fuel cell system. Currently, the plates in the stack are mostly flat and square. Due to stress concentration and other reasons, the high-pressure gas in the gas tank cannot directly enter the plate for reaction, and it needs to be decompressed, which reduces the reaction efficiency of the stack. In addition, the square stack has a low space utilization rate in some cases.

[0003] At the same time, placing the electrode plates at a certain angle can effectively promote the discharge of product water. However, the current electrode plate designs are mostly flat. If the electrode plates need to be placed at an angle, the entire stack needs to be placed at an angle, which increases the difficulty of the overall layout of the fuel cell and reduces space utilization. Summary of the invention

[0004] In view of this, an object of the present invention is to provide a disc-shaped fuel cell bipolar plate and a fuel cell stack to solve the problem of poor drainage effect of the plates set in the prior art.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention discloses a disc-shaped fuel cell bipolar plate, comprising a bipolar plate body, the bipolar plate body is funnel-shaped, the outer surface of the bipolar plate body is an anode surface, the inner surface of the bipolar plate body is a cathode surface, the anode surface is provided with a hydrogen guide area, a hydrogen distribution area and a hydrogen reaction area which are arranged in an annular manner and are interconnected from the small diameter end to the large diameter end, the hydrogen distribution area is provided with a plurality of oxygen inlet holes which penetrate the bipolar plate body, the hydrogen reaction area is located inside the edge of the anode surface, and a plurality of hydrogen outlet holes which penetrate the bipolar plate body are provided on the edge of the hydrogen reaction area close to the large diameter end of the bipolar plate body, a plurality of cathode flow channel units are evenly distributed on the circumference of the cathode surface, a plurality of the cathode flow channel units are interconnected with a plurality of the oxygen inlet holes, and part of the flow channels in the cathode flow channel units penetrate the large diameter end edge of the bipolar plate body, a plurality of connecting plates are provided on the circumference of the large diameter end edge of the bipolar plate body, and the connecting plates are fixed on the bipolar plate body.

[0007] Furthermore, a plurality of circumferentially evenly distributed hydrogen guide flow channels are provided in the hydrogen guide area, a plurality of circumferentially distributed protrusions are provided in the hydrogen distribution area, the protrusions are arranged flush with the anode surface, a plurality of circumferentially evenly distributed anode flow channels are provided in the hydrogen reaction area, the two ends of the anode flow channel respectively point to the two ends of the bipolar plate body, an annular hydrogen collecting groove is provided on one end of the anode flow channel close to the large diameter end of the bipolar plate body, and the hydrogen collecting groove is connected to the anode flow channel and the hydrogen outlet.

[0008] Furthermore, the cathode flow channel unit includes three main channels distributed in a fan shape, one end of the main channel located on both sides passes through the edge of the large diameter end of the bipolar plate body, and the other end is connected to the oxygen inlet hole, and a plurality of primary branch channels are arranged between adjacent main channels, one end of the primary branch channel is connected to the main channel arranged in the middle, and the other end passes through the large diameter end of the bipolar plate body, and secondary branch channels are arranged between the primary branch channel and the main channel located at the edge, one end of the secondary branch channel is connected to the main channel arranged on both sides, and the other end is connected to the secondary branch channel.

[0009] Furthermore, annular grooves are respectively provided on the outer sides of the plurality of oxygen inlet holes on the anode surface and on the outer sides of the plurality of hydrogen outlet holes on the cathode surface, and a first rubber ring and a second rubber ring are respectively provided in the annular grooves.

[0010] Furthermore, an isolation area is provided between the oxygen inlet hole and the small diameter end of the battery bipolar plate.

[0011] Furthermore, a fuel cell stack includes a plurality of disc-shaped fuel cell bipolar plates, and also includes a funnel-shaped upper cover plate and a lower cover plate, a hydrogen inlet pipe is provided on the small diameter end of the outer side surface of the upper cover plate, a plurality of oxygen inlet pipes are provided on the outer circumference of the hydrogen inlet pipe, a first hydrogen outlet pipe is provided on the small diameter end of the inner side surface of the lower cover plate, a plurality of second hydrogen outlet pipes are provided on the outer circumference of the first hydrogen outlet pipe, a plurality of bipolar plate bodies are closely stacked, the inner side surface of the upper cover plate is fitted with the anode surface of the uppermost bipolar plate body, and the end of the hydrogen inlet pipe fully covers the hydrogen guide area, a plurality of oxygen inlet pipes are connected with a plurality of oxygen inlet holes respectively, the outer side surface of the lower cover plate is closely fitted with the cathode surface of the lowermost bipolar plate body, the end of the first hydrogen outlet pipe is connected with the small diameter end of the bipolar plate body, a plurality of the second hydrogen outlet pipes are connected with a plurality of hydrogen outlet holes respectively, and a plurality of screws are provided on the connecting plate, the screws are used to closely connect the upper cover plate, the lower cover plate and a plurality of bipolar plate bodies.

[0012] Furthermore, it also includes a capsule-shaped shell, which fully covers the upper cover plate, the lower cover plate and a plurality of bipolar plate bodies, and the oxygen inlet pipe, the hydrogen inlet pipe, the first hydrogen outlet pipe and the second hydrogen outlet pipe are connected to the external space of the capsule-shaped shell, and an exhaust pipe is provided on the end of the capsule-shaped shell below the lower cover plate, and the exhaust pipe is connected to the interior of the capsule-shaped shell.

[0013] Furthermore, a gas-liquid separation element is provided on the discharge pipe.

[0014] The beneficial effects of the present invention are:

[0015] (1) The present invention adopts a method of using both branch channels and main channels in the layout of the flow channels. The larger cross-sectional area of ​​the main channel can quickly discharge the product water. At the same time, the smaller branch channels can be more densely distributed on the electrode plate, so that the gas is more evenly distributed on the electrode plate.

[0016] (2) The capsule-shaped shell of the present invention can effectively provide external protection for the battery stack, preventing the battery stack from being exposed to the outside world for a long time, causing the parts to be oxidized, and reducing the efficiency and durability. At the same time, the oxygen that has not reacted completely can be collected and reused.

[0017] (3) The cross section of the curved annular electrode plate of the present invention presents a certain angle, and there is no need to tilt the entire battery stack, thereby improving the efficiency of discharging product water.

[0018] Other advantages, objectives and features of the present invention will be described in the following description and will be apparent to those skilled in the art to some extent, or those skilled in the art may be taught from the practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to make the purpose, technical solution and beneficial effects of the present invention clearer, the present invention provides the following drawings for illustration:

[0020] Figure 1 is a three-dimensional schematic diagram of a bipolar plate of the present invention;

[0021] Figure 2 A three-dimensional schematic diagram of a bipolar plate of the present invention from another perspective;

[0022] Figure 3 A schematic diagram of a top view of the anode surface of the bipolar plate of the present invention;

[0023] Figure 4 A schematic top view of the cathode surface of the bipolar plate of the present invention;

[0024] Figure 5 It is a three-dimensional schematic diagram of the battery stack of the present invention;

[0025] Figure 6 A three-dimensional schematic diagram of the interior of a battery stack of the present invention (a number of bipolar plates stacked in the middle are hidden);

[0026] Figure 7 It is a three-dimensional schematic diagram of a capsule-shaped casing of a battery stack of the present invention;

[0027] Figure 8 It is a three-dimensional schematic diagram of the upper cover plate of the present invention;

[0028] Fig. 9 It is a three-dimensional schematic diagram of the lower cover plate of the present invention.

[0029] The following are marked in the accompanying drawings:

[0030] 1. Bipolar plate body; 2. Anode surface; 3. Oxygen inlet hole; 4. Hydrogen outlet hole; 5. Hydrogen guide channel; 6. Protrusion; 7. Anode channel; 8. Hydrogen collecting tank; 9. First rubber ring; 10. Cathode surface; 11. Second rubber ring; 12. Main channel; 13. Primary branch channel; 14. Secondary branch channel; 15. Isolation area; 16. Connecting plate; 17. Cathode channel unit; 18. Upper cover plate; 19. Oxygen inlet pipe; 20. Hydrogen inlet pipe; 21. Lower cover plate; 22. Second hydrogen outlet pipe; 23. First hydrogen outlet pipe; 24. Capsule-shaped shell; 25. Exhaust pipe. DETAILED DESCRIPTION

[0031] like Figure 1 to Figure 4 As shown, a disc-shaped fuel cell bipolar plate of the present invention comprises a bipolar plate body 1, the bipolar plate body 1 is funnel-shaped, specifically, it can be described as a hollow truncated cone with a small upper end and a large lower end, and the outer surface of the bipolar plate body 1 is defined as an anode surface 2, and the inner surface of the bipolar plate body 1 is defined as a cathode surface 10, and the anode surface 2 is provided with a hydrogen guide area, a hydrogen distribution area and a hydrogen reaction area which are arranged in an annular manner and are interconnected from the small diameter end to the large diameter end, and the hydrogen distribution area is provided with a plurality of oxygen inlet holes 3 (through hole arrangement) which are arranged through the bipolar plate body 1, and the hydrogen reaction area is located inside the edge of the anode surface 2, that is, it does not exceed the large diameter edge of the anode surface 2, and A number of hydrogen outlet holes 4 are provided on the edge of the large diameter end of the bipolar plate main body 1 near the hydrogen reaction zone, and are arranged through the bipolar plate main body 1. A number of cathode flow channel units 17 are evenly distributed on the circumference of the cathode surface 10. A number of flow channels (referring to grooves opened on the bipolar plate theme) are arranged in the flow channel unit. A number of cathode flow channel units 17 are interconnected with a number of oxygen inlet holes 3, and part of the flow channels in the cathode flow channel unit 17 are arranged through the large diameter end edge of the bipolar plate main body 1, which can be understood as being connected to the outside of the large diameter edge of the bipolar plate theme. A number of connecting plates 16 are arranged on the circumference of the large diameter end edge of the bipolar plate main body 1, and the connecting plates 16 are fixed on the bipolar plate main body 1.

[0032] The working principle of the above technical solution is:

[0033] By setting the bipolar plate in a funnel shape, the cathode flow channel unit 17 is tilted in the vertical plane, that is, after the oxygen on the cathode surface 10 participates in the reaction, water is generated in the cathode flow channel unit 17. Under the force of its gravity and the blowing of oxygen in the cathode flow channel unit 17, the water can be quickly discharged from the flow channel that runs through the edge of the bipolar plate body 1, thereby accelerating the discharge of product water and improving the reaction efficiency of the fuel cell.

[0034] In one practicable manner, a plurality of circumferentially uniformly distributed hydrogen guide flow channels 5 are provided in the hydrogen guide area, and the layout direction of the hydrogen guide flow channels 5 is to guide the hydrogen from the small diameter section of the anode surface 2 to the large diameter end. At the same time, one end of the hydrogen guide flow channel 5 is arranged through the small diameter end, and a plurality of circumferentially distributed protrusions 6 are provided in the hydrogen distribution area. The protrusion 6 is arranged flush with the anode surface 2. It should be noted that the protrusion 6 is arranged in an annular groove, so the protrusion 6 can be arranged flush with the anode surface 2. A plurality of circumferentially uniformly distributed anode flow channels 7 are provided in the hydrogen reaction area, and the two ends of the anode flow channel 7 respectively point to the two ends of the bipolar plate body 1, and an annular hydrogen collecting groove 8 is provided on the end of the anode flow channel 7 close to the large diameter end of the bipolar plate body 1, and the hydrogen collecting groove 8 is connected to both the anode flow channel 7 and the hydrogen outlet 4.

[0035] When hydrogen flows from the hydrogen guide flow channel 5 to the hydrogen distribution area, the hydrogen will contact with a number of protrusions 6, and the hydrogen will be dispersed during the contact process, so that the hydrogen will move to the hydrogen collecting tank 8 through the end of each anode flow channel 7, and react in the process of movement. At the same time, the incompletely reacted hydrogen will be guided by the hydrogen collecting tank 8 (the reason for the collection and guidance is that after multiple bipolar plates are stacked, the contact surfaces of adjacent bipolar plates should be provided with sealants, etc. to avoid mutual gas flow between the two), so that the incompletely reacted hydrogen is discharged from the hydrogen outlet 4.

[0036] In one practicable manner, Figure 4 As shown, the cathode flow channel unit 17 includes three fan-shaped main channels 12, one end of the main channel 12 located on both sides passes through the edge of the large diameter end of the bipolar plate body 1, and the other end is connected to the oxygen inlet hole 3, and a plurality of primary branch channels 13 are arranged between adjacent main channels 12, one end of the primary branch channel 13 is connected to the main channel 12 arranged in the middle, and the other end is arranged to pass through the large diameter end of the bipolar plate body 1, and secondary branch channels 14 are arranged between the primary branch channel 13 and the main channel 12 located at the edge, one end of the secondary branch channel 14 is connected to the main channel 12 arranged on both sides, and the other end is connected to the secondary branch channel 14.

[0037] That is, oxygen enters from the main channel 12, and then disperses to each primary branch channel 13 and the secondary branch channel 14 for reaction, that is, the water generated in each channel flows to the main channel 12 under the action of gravity and oxygen blowing, and then the water in each channel can be quickly discharged after being collected through the main channel 12. Of course, it is not difficult to understand that a number of interconnected small channels can also be set to improve the uniform distribution effect of oxygen on the cathode surface 10. At the same time, it is not difficult to understand that the primary branch channel 13 and the secondary branch channel 14 should be set obliquely in the cathode surface 10.

[0038] In one practicable manner, annular grooves are respectively provided on the outer sides of the plurality of oxygen inlet holes 3 on the anode surface 2 and on the outer sides of the plurality of hydrogen outlet holes 4 on the cathode surface 10, and a first rubber ring 9 and a second rubber ring 11 are respectively provided in the annular grooves to achieve sealing and prevent hydrogen and oxygen from entering other reaction surfaces.

[0039] In one practicable manner, an isolation area 15 is provided between the oxygen inlet hole 3 and the small diameter end of the battery bipolar plate. The isolation area 15 refers to an area where no flow channel is opened, which blocks the flow of oxygen to prevent it from being discharged from the small diameter section of the bipolar plate, and also prevents hydrogen from entering the cathode surface 10 from this part.

[0040] It is not difficult to understand that in the prior art, the existing flow channels include linear flow channels such as parallel flow channels, serpentine flow channels, interdigitated flow channels, etc., and mesh flow channels such as snowflake-shaped flow channels and spider-web-shaped flow channels. The current linear flow channel design leads to a higher pressure drop, especially under high flow operation conditions, which will increase the energy consumption of the system. In addition, the longer flow channel makes the gas distribution uneven, especially in the inlet and outlet areas of the flow channel. This leads to a decrease in the performance of the fuel cell in the local area. The mesh flow channel has a large internal resistance and poor drainage performance, and the accumulation of product water reduces the reaction rate.

[0041] The flow channel design in this technical solution uses a branch channel and a main channel 12, and arranges them in a mesh on the electrode plate, so that the main channel 12 has a larger cross-sectional area and can quickly discharge the product water. At the same time, the smaller branch channels can be more densely distributed on the electrode plate, so that the gas is more evenly distributed on the electrode plate.

[0042] In one practicable manner, Figure 5-Figure 9As shown, a battery stack includes a plurality of bipolar plates, and also includes a funnel-shaped upper cover plate 18 and a lower cover plate 21. A hydrogen inlet pipe 20 is provided on the small diameter end of the outer side of the upper cover plate 18, and a plurality of oxygen inlet pipes 19 are provided on the outer circumference of the hydrogen inlet pipe 20. A first hydrogen outlet pipe 23 is provided on the small diameter end of the inner side of the lower cover plate 21. A flow valve is provided on the first hydrogen outlet pipe 23 to control the inner wall pressure. A plurality of second hydrogen outlet pipes 22 are provided on the outer circumference of the first hydrogen outlet pipe 23. A plurality of bipolar plate bodies 1 are closely stacked, and the inner side of the upper cover plate 18 is connected to the uppermost bipolar plate 18. The anode surface 2 of the plate body 1 is arranged in close contact, and the end of the hydrogen inlet pipe 20 fully covers the hydrogen guide area, a plurality of oxygen inlet pipes 19 are connected to a plurality of oxygen inlet holes 3, and the outer side surface of the lower cover plate 21 is closely connected to the cathode surface 10 of the lowermost bipolar plate body 1, and the end of the first hydrogen outlet pipe 23 is connected to the small diameter end of the bipolar plate body 1, and a plurality of second hydrogen outlet pipes 22 are connected to a plurality of hydrogen outlet holes 4, and a plurality of screws are provided on the connecting plate 16, and the screws are used to closely connect the upper cover plate 18, the lower cover plate 21 and a plurality of bipolar plate bodies 1.

[0043] The working principle of the above electric push is:

[0044] Hydrogen enters the small diameter end of each bipolar plate stack from the hydrogen inlet pipe 20. Since a section of the hydrogen guide flow channel 5 runs through the small diameter end of the bipolar plate body 1, the gas can enter the anode surface 2 through the hydrogen guide flow channel 5, and then enter the anode flow channel 7 through the gas distribution area and evenly distribute on the anode surface 2. It is decomposed into protons and electrons by the catalyst. The electrons flow into the cathode through the external circuit, and the protons enter the anode through the proton exchange membrane. The unreacted hydrogen enters the second hydrogen outlet pipe 22 in the lower cover plate 21 through the hydrogen outlet hole 4 and is discharged from the stack. Oxygen enters the oxygen inlet hole 3 set on the cathode surface 10 from the oxygen (air) inlet pipe, and is evenly distributed on the electrode cathode surface 10 through the main flow channel 12, the primary branch flow channel 13 and the secondary branch flow channel 14 connected to the main flow channel 12, and reacts with the protons and electrons from the anode surface 2 to generate product water. The product water generated in the primary branch channel 13 and the secondary branch channel 14 is purged into the main channel 12 and quickly discharged from the stack, and is collected by the capsule-shaped shell 24 and then discharged through the discharge pipe 25 located at the lower end of the capsule-shaped shell 24.

[0045] It is not difficult to understand that sealant is arranged on the circumferential non-gas outlet area of ​​the bipolar plate body 1, and the bipolar plate body 1 is made of metal, graphite or other composite materials; the upper cover plate 18 and the lower cover plate 21 are made of metal, carbon fiber or other composite materials; and a connecting plate 16 is provided on the bipolar plate body 1, the upper cover plate 18 and the lower cover plate 21.

[0046] At the same time, the shorter flow channel length makes the reaction gas concentration more evenly distributed in the flow channel. Because the cathode plate is provided with a main channel 12 with a larger cross-sectional area, the water in the more densely distributed branch channels can quickly drain into the main channel 12 and then be discharged by the main channel 12 without affecting the reaction of the branch channels. The overall circular design enables it to withstand greater gas pressure.

[0047] In one practicable manner, it also includes a capsule-shaped shell 24, which fully covers the upper cover plate 18, the lower cover plate 21 and the plurality of bipolar plate bodies 1, and the oxygen inlet pipe 19, the hydrogen inlet pipe 20, the first hydrogen outlet pipe 23 and the second hydrogen outlet pipe 22 are connected to the external space of the capsule-shaped shell 24, and an exhaust pipe 25 is provided on the end of the capsule-shaped shell 24 located below the lower cover plate 21, and the exhaust pipe 25 is connected to the interior of the capsule-shaped shell 24.

[0048] The capsule-shaped shell can effectively provide external protection for the battery stack, preventing the battery stack from being exposed to the outside world for a long time, which may cause the parts to be oxidized and reduce the efficiency and durability. At the same time, it can collect the incompletely reacted oxygen for secondary use.

[0049] In one practicable manner, a gas-liquid separation element, such as a gas-liquid separator in the prior art, is provided on the discharge pipe 25 to separate water from oxygen and prevent the recycled oxygen from carrying water into the cathode surface 10 .

[0050] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made in form and details without departing from the scope defined by the claims of the present invention.

Claims

1. A disc-shaped fuel cell bipolar plate, characterized in that: The invention comprises a bipolar plate body (1), wherein the bipolar plate body (1) is funnel-shaped, the outer surface of the bipolar plate body (1) is an anode surface (2), the inner surface of the bipolar plate body (1) is a cathode surface (10), the anode surface (2) is provided with a hydrogen guide area, a hydrogen distribution area and a hydrogen reaction area which are arranged in an annular manner and are interconnected from a small diameter end to a large diameter end, the hydrogen distribution area is provided with a plurality of oxygen inlet holes (3) which are arranged through the bipolar plate body (1), the hydrogen reaction area is located inside the edge of the anode surface (2), and the hydrogen reaction area is close to the bipolar plate. A plurality of hydrogen outlet holes (4) penetrating the bipolar plate body (1) are provided on the edge of one end with a large diameter of the plate body (1); a plurality of cathode flow channel units (17) are evenly distributed on the circumference of the cathode surface (10); the plurality of cathode flow channel units (17) are interconnected with the plurality of oxygen inlet holes (3); and part of the flow channels in the cathode flow channel units (17) penetrate the edge of the large diameter end of the bipolar plate body (1); a plurality of connecting plates (16) are provided on the circumference of the edge of the large diameter end of the bipolar plate body (1); and the connecting plates (16) are fixed to the bipolar plate body (1); The cathode flow channel unit (17) comprises three main flow channels (12) distributed in a fan shape, one end of the main flow channels (12) located on both sides penetrates the edge of the large diameter end of the bipolar plate body (1), and the other end is connected to the oxygen inlet hole (3), a plurality of primary branch flow channels (13) are arranged between adjacent main flow channels (12), one end of the primary branch flow channel (13) is connected to the main flow channel (12) arranged in the middle, and the other end is arranged to penetrate the large diameter end of the bipolar plate body (1), and a secondary branch flow channel (14) is arranged between the primary branch flow channel (13) and the main flow channel (12) located at the edge, one end of the secondary branch flow channel (14) is connected to the main flow channel (12) arranged on both sides, and the other end is connected to the primary branch flow channel (13).

2. A disc-shaped fuel cell bipolar plate according to claim 1, characterized in that: A plurality of circumferentially evenly distributed hydrogen guide flow channels (5) are provided in the hydrogen guide area, a plurality of circumferentially distributed protrusions (6) are provided in the hydrogen distribution area, the protrusions (6) are arranged flush with the anode surface (2), a plurality of circumferentially evenly distributed anode flow channels (7) are provided in the hydrogen reaction area, the two ends of the anode flow channels (7) respectively point to the two ends of the bipolar plate body (1), an annular hydrogen collection groove (8) is provided at one end of the anode flow channel (7) close to the large diameter end of the bipolar plate body (1), and the hydrogen collection groove (8) is connected to both the anode flow channel (7) and the hydrogen outlet hole (4).

3. A disc-shaped fuel cell bipolar plate according to claim 1, characterized in that: Annular grooves are respectively provided on the outer sides of the plurality of oxygen inlet holes (3) on the anode surface (2) and the outer sides of the plurality of hydrogen outlet holes (4) on the cathode surface (10), and a first rubber ring (9) and a second rubber ring (11) are respectively provided in the annular grooves.

4. A disc-shaped fuel cell bipolar plate according to claim 1, characterized in that: An isolation area (15) is provided between the oxygen inlet hole (3) and the small diameter end of the bipolar plate body (1).

5. A battery stack, characterized in that: A disc-shaped fuel cell bipolar plate comprising a plurality of bipolar plates as claimed in any one of claims 1 to 4, and further comprising a funnel-shaped upper cover plate (18) and a lower cover plate (21), wherein a hydrogen inlet pipe (20) is provided on the small diameter end of the outer side surface of the upper cover plate (18), and a plurality of oxygen inlet pipes (19) are provided on the outer circumference of the hydrogen inlet pipe (20), a first hydrogen outlet pipe (23) is provided on the small diameter end of the inner side surface of the lower cover plate (21), and a plurality of second hydrogen outlet pipes (22) are provided on the outer circumference of the first hydrogen outlet pipe (23), and a plurality of bipolar plate bodies (1) are closely stacked, and the inner side surface of the upper cover plate (18) is in contact with the anode of the uppermost bipolar plate body (1). The upper cover plate (18), the lower cover plate (21) and the lower cover plate (21) are arranged in close contact with the cathode surface (10) of the lower bipolar plate body (1), and the end of the hydrogen inlet pipe (20) fully covers the hydrogen guide area. The plurality of oxygen inlet pipes (19) are connected to the plurality of oxygen inlet holes (3) respectively. The outer side surface of the lower cover plate (21) is closely contacted with the cathode surface (10) of the lower bipolar plate body (1). The end of the first hydrogen outlet pipe (23) is connected to the small diameter end of the bipolar plate body (1), and the plurality of the second hydrogen outlet pipes (22) are connected to the plurality of the hydrogen outlet holes (4) respectively. The connecting plate (16) is provided with a plurality of screws, which are used to closely connect the upper cover plate (18), the lower cover plate (21) and the plurality of bipolar plate bodies (1).

6. A fuel cell stack according to claim 5, characterized in that: The invention also comprises a capsule-shaped shell (24), wherein the capsule-shaped shell (24) completely covers the upper cover plate (18), the lower cover plate (21) and the plurality of bipolar plate bodies (1), and the oxygen inlet pipe (19), the hydrogen inlet pipe (20), the first hydrogen outlet pipe (23) and the second hydrogen outlet pipe (22) are connected to the external space of the capsule-shaped shell (24), and an exhaust pipe (25) is provided at the end of the capsule-shaped shell (24) below the lower cover plate (21), and the exhaust pipe (25) is connected to the interior of the capsule-shaped shell (24).

7. A fuel cell stack according to claim 6, characterized in that: The discharge pipe (25) is provided with a gas-liquid separation element.

Images