A closed air-cooled metal bipolar plate and a method for manufacturing the same

Abstract

The application discloses a closed air-cooled metal bipolar plate and a preparation method thereof. From top to bottom, the bipolar plate comprises an anode plate, an anode inlet-outlet gas passage plate, a cathode inlet-outlet gas passage plate and a cathode plate; the cooling heat dissipation plate, the anode inlet-outlet gas passage plate and the cathode inlet-outlet gas passage plate are arranged between the anode plate and the cathode plate; the upper and lower surfaces of the cooling heat dissipation plate are provided with support surfaces; the support surfaces are composed of a plurality of staggered polygonal structures in an array, each staggered polygonal structure penetrates through the upper and lower surfaces of the heat dissipation plate, each staggered polygonal structure on each surface is provided with a heat dissipation opening, the heat dissipation openings are arranged adjacently and penetrate through each other. Through a four-layer welding process, the structure that the heat dissipation field needs to be sealed by a thick sealing ring in the prior art is cancelled, the air field combination layer is designed with a double-side sealing counter-pressure structure on each side according to the step-by-step sealing feature, the air field sealing reliability is guaranteed, meanwhile, the straight-through type gas inlet structure is adopted for the inlet-outlet gas structure, compared with the step-by-step inlet-outlet gas structure, the utilization rate of the bipolar plate is improved.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell bipolar plates, specifically relating to a closed-type air-cooled metal bipolar plate and its preparation method. Background Technology

[0002] A fuel cell is a power generation device that converts chemical energy into electrical energy through an electrochemical reaction. Hydrogen gas is introduced into the anode and air is introduced into the cathode. Under the action of a proton exchange membrane and a catalyst, hydrogen gas loses electrons, and hydrogen protons reach the cathode and react with oxygen and electrons to produce water.

[0003] Currently, fuel cell technology has officially moved from the laboratory to industrialization, and its application areas are constantly expanding, such as transportation, distributed power generation, and energy storage. Commercial vehicles, electric vehicles, and drones have become the main application scenarios for the development of fuel cell technology. With the opening up of electric vehicle and drone scenarios, air-cooled fuel cell technology has been significantly improved.

[0004] Closed-loop air cooling is one of the latest air-cooled fuel cell technologies. Compared to open-loop air-cooled fuel cells, it offers longer lifespan, better performance, and lower cost. Current closed-loop air-cooled bipolar plate structures mostly consist of an anode plate, a heat sink plate, a cathode plate, an air field sealing ring, and a heat sink sealing ring. The core structural elements are the air intake method and the sealing structure. Existing closed-loop air-cooled bipolar plates primarily use two structures: 1. A traditional straight-through air intake / exhaust structure, which has a risk of seal failure due to only one side of the inner surface being sealed and requiring the flow channel and frame to build seal support strength; 2. A layered air intake / exhaust structure referencing liquid-cooled plates, which, while offering reliable sealing performance, has low plate utilization and requires two additional sets of air intake / exhaust channel plates, resulting in higher costs. Furthermore, both of these traditional closed-loop air-cooled structures require sealing rings with a thickness equivalent to 4 times that of the cooling heat sink plate between the anode and cathode air intake / exhaust channel plates for sealing.

[0005] The existing closed-loop air-cooled bipolar plate cooling heat sink has a large-cycle DC channel structure. The channel grooves and channel ridges form the heat dissipation channels on both sides of the bipolar plate. Considering the heat dissipation effect, the channel cycle is relatively large, so the overall structural strength is relatively weak. Summary of the Invention

[0006] This invention provides a closed-loop air-cooled metal bipolar plate and its manufacturing method. Through a four-layer welding process, it eliminates the need for a thick sealing ring in existing technologies to achieve a sealed heat dissipation field. Combining the characteristics of a layered sealing design, each side of the seal is designed with a double-sided sealing pressure structure to ensure reliable air field sealing. Simultaneously, the air inlet and outlet structure adopts a direct-flow air inlet structure, which improves the utilization rate of the plate compared to the layered air inlet and outlet structure. The staggered rectangular heat dissipation structure of this invention improves the heat dissipation efficiency and support strength of the heat sink, solving the technical difficulties of weak support and limited heat dissipation capacity in traditional direct-flow heat dissipation structures.

[0007] The technical solution of this invention is as follows.

[0008] A closed-loop air-cooled metal bipolar plate, comprising, from top to bottom, an anode plate, an anode inlet / outlet air channel plate, a cathode inlet / outlet air channel plate, and a cathode plate; a cooling plate, an anode inlet / outlet air channel plate, and a cathode inlet / outlet air channel plate are disposed between the anode plate and the cathode plate.

[0009] The cooling plate has support surfaces on both its upper and lower surfaces; each support surface is composed of an array of staggered polygonal structures, each staggered polygonal structure penetrating both the upper and lower surfaces of the cooling plate, and each staggered polygonal structure on each surface has a heat dissipation vent, which are arranged adjacently and interconnected. Figure 2-2 As shown, half of the heat dissipation outlet a flows to heat dissipation outlet b, which is connected to heat dissipation outlet c. Therefore, heat dissipation outlet a and heat dissipation outlet c are adjacent to each other and interconnected.

[0010] More preferably, the cooling heat dissipation plate is provided with support surfaces on both the upper and lower surfaces; the support surfaces are composed of an array of multiple staggered rectangular structures, each staggered rectangular structure penetrates both the upper and lower surfaces of the heat dissipation plate, each staggered rectangular structure on each surface has two heat dissipation holes, and the four heat dissipation holes are arranged adjacently and interconnected.

[0011] More preferably, both the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate are provided with a first support surface, a second support surface, a third support surface, a sealing area, an anode inlet / outlet gas channel, and a cathode inlet / outlet gas channel.

[0012] The first support surface of the inlet / outlet channel plate is located at the outermost edge of the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate, and the second support surface of the inlet / outlet channel plate is located on the plate surface of the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate; the second support surface of the inlet / outlet channel plate is provided with an anode inlet / outlet channel and a cathode inlet / outlet channel; wherein both the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate are provided with an inlet / outlet channel plate sealing area, and when the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate are welded or bonded together, an inlet / outlet channel plate sealing area is formed;

[0013] The first support surfaces of the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate are attached and connected to form an outer welding line between the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate.

[0014] The second support surfaces of the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate are attached and connected to form an inner welding line between the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate, so that the anode inlet / outlet gas channels and the cathode inlet / outlet gas channels on the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate are interconnected.

[0015] More preferably, the anode plate is provided with a cathode cavity, an anode cavity, an anode reaction zone, an anode distribution zone, an anode sealing zone, and an anode inlet / outlet; the cathode cavity and anode cavity are respectively located on the plate surface near the side, and the anode reaction zone is located at the center of the plate surface; the anode cavity is connected to the anode reaction zone through the anode inlet / outlet and the anode distribution zone; the anode sealing zone is located at the edge of the entire anode plate, such as... Figure 6 The location indicated by the black outline.

[0016] More preferably, the cathode plate is provided with a cathode cavity, an anode cavity, a cathode distribution area, a cathode sealing area, a cathode inlet / outlet, and a cathode reaction area; the cathode cavity and anode cavity are respectively located on the plate surface near the side; the cathode reaction area is located at the center of the plate surface; the cathode cavity is connected to the cathode reaction area through the cathode inlet / outlet and the cathode distribution area; the cathode sealing area is located at the edge of the entire cathode plate; the cathode sealing area is located at... Figure 7 The location indicated by the black outline.

[0017] More preferably, the third support surface of the air inlet / outlet channel plate is connected to the anode sealing area of ​​the anode plate and the cathode sealing area of ​​the cathode plate, respectively.

[0018] A method for preparing a closed-loop air-cooled metal bipolar plate includes the following steps:

[0019] 1) The first support surfaces of the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate are attached and welded together to form an outer welding line between the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate to prevent gas leakage.

[0020] 2) The second support surfaces of the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate are attached together and internally welded to form an internal welding line between the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate to prevent gas leakage. The two welding operations fix the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate into a whole.

[0021] 3) Weld the anode sealing area of ​​the anode plate and the cathode sealing area of ​​the cathode plate to the third support surface of the inlet and outlet gas channel plate, respectively. The welding area of ​​the anode plate is as follows: Figure 6 As shown in the middle welding line 1, the cathode plate welding line area is as follows: Figure 7 As shown in the middle welding line 2, the anode plate, the anode inlet and outlet gas channel plate, the cathode inlet and outlet gas channel plate and the cathode plate form a whole. The anode gas can only go from the anode cavity through the anode inlet and outlet channel to the anode inlet and outlet, and then enter the anode plate. Similarly, the cathode gas can only go from the cathode cavity through the cathode inlet and outlet channel to the cathode inlet and outlet, and then enter the cathode plate.

[0022] 4) such as Figure 2-1As shown, the heat sink needs to be fixed together with the anode plate and cathode plate by welding. The boss and groove of the heat sink are designed with multiple solder points A and B. The boss of the heat sink is welded to the sealing area of ​​the anode plate, and the position of the solder point is shown as solder point A. The groove of the heat sink is welded to the sealing area of ​​the cathode plate, and the position of the solder point is shown as solder point B.

[0023] Compared with the prior art, the advantages of the present invention are:

[0024] (1) The present invention uses a four-stage welding process to weld the anode and cathode plates and the anode and cathode inlet / outlet gas channels together, which reduces the risk of sealing failure caused by the sealing strip, simplifies the assembly tooling, and improves the overall structural strength. At the same time, the direct-flow gas inlet / outlet method improves the plate utilization rate and reduces costs compared to the layered type.

[0025] (2) The present invention adopts an array of staggered rectangular structures, with four heat dissipation ports that are interconnected and adjacent to each other, which greatly increases the heat exchange efficiency of the air and increases the support strength of the heat dissipation plate. Attached Figure Description

[0026] Figure 1 Exploded view of a closed-loop air-cooled metal bipolar plate structure;

[0027] Figure 2-1 Schematic diagram of the cooling heat dissipation plate structure;

[0028] Figure 2-2 Schematic diagram of the cooling heat dissipation plate structure;

[0029] Figure 3 This is a cross-sectional view of the cooling fin.

[0030] Figure 4 This is a schematic diagram of the air inlet and outlet channel structure;

[0031] Figure 5 This is a schematic diagram of the welding path for the air inlet and outlet channels;

[0032] Figure 6 This is a schematic diagram of the anode plate structure;

[0033] Figure 7 This is a schematic diagram of the cathode plate structure;

[0034] Figure 8 A cross-sectional view of the air inlet and outlet assembly; Figure 9 This is the polarization curve.

[0035] The components in the diagram are as follows:

[0036] Anode plate 1, Anode inlet / outlet gas channel plate 2, Cathode inlet / outlet gas channel plate 3, Cooling plate 4, Cathode plate 5, Lower support surface of cooling plate 10, Upper support surface of cooling plate 11, Heat dissipation port on the first upper support surface of cooling plate 12, Heat dissipation port on the second upper support surface of cooling plate 12, Heat dissipation port on the lower support surface of the first cooling plate 14, Heat dissipation port on the lower support surface of the second cooling plate 15, Cathode cavity port 20, Anode cavity port 21, Anode reaction zone 22, Anode distribution zone 23, Anode sealing zone 24, Anode inlet / outlet 25, Anode inlet / outlet and cathode inlet / outlet gas channel plate 30. Welding line on the outer side of the guide plate; 31. Welding line on the inner side of the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate; 32. Anode inlet / outlet channel; 33. Cathode inlet / outlet channel; 34. Welding line between the anode inlet / outlet channel plate and the anode plate; 35. Sealing area of ​​the inlet / outlet channel plate; 36. First support surface of the inlet / outlet channel plate; 37. Second support surface of the inlet / outlet channel plate; 38. Third support surface of the inlet / outlet channel plate; 39. Welding line between the cathode inlet / outlet channel plate and the cathode plate; 40. Cathode distribution area; 41. Cathode sealing area; 42. Cathode inlet / outlet; 43. Cathode reaction area. Detailed Implementation

[0037] The technical solutions are illustrated in the following description with specific figures to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and similar extended embodiments made by those skilled in the art without inventive effort are all within the scope of protection of this invention.

[0038] Example 1

[0039] Figure 1The described structure is a closed-loop air-cooled metal bipolar plate structure, which consists of an anode plate 1, an anode inlet / outlet air channel plate 2, a cathode inlet / outlet air channel plate 3, a cooling plate 4, and a cathode plate 5, arranged from top to bottom as anode plate 1, anode inlet / outlet air channel plate 2, cathode inlet / outlet air channel plate 3, and cathode plate 5. The cooling plate 4, anode inlet / outlet air channel plate 2, and cathode inlet / outlet air channel plate 3 are disposed between the anode plate 1 and the cathode plate 5. The anode plate 1 is provided with a cathode cavity 20, an anode cavity 21, an anode reaction zone 22, an anode distribution zone 23, an anode sealing zone 24, and an anode inlet / outlet 25. The anode inlet / outlet air channel plate 2 and the cathode inlet / outlet air channel plate 3 are each supported by a first support surface 36, a second support surface 37, and a third support surface 38. 8. The inlet and outlet air passage plate sealing area 35 is composed of the anode inlet and outlet air passage 32 and the cathode inlet and outlet air passage 33. The cooling heat dissipation plate 4 is divided into an upper support surface 11 and a lower support surface 10. The upper support surface 11 is designed with an array of N staggered rectangular structures. Each staggered rectangular structure has a first upper support surface heat dissipation port 12 and a second upper support surface heat dissipation port 13. Similarly, the lower support surface 10 is also designed with an array of N staggered rectangular structures. Each staggered rectangular structure has a first lower support surface heat dissipation port 14 and a second lower support surface heat dissipation port 15. The first upper support surface heat dissipation port 12, the second upper support surface heat dissipation port 13, the first lower support surface heat dissipation port 14, and the second lower support surface heat dissipation port 15 are arranged adjacent to each other and interconnected. Figure 2-2 As shown, half of the heat dissipation outlet a flows to heat dissipation outlet b, which is connected to heat dissipation outlet c. Therefore, heat dissipation outlet a and heat dissipation outlet c are adjacent to each other and interconnected.

[0040] The cathode plate 5 is provided with a cathode cavity 20, an anode cavity 21, a cathode distribution area 40, a cathode sealing area 41, a cathode inlet / outlet 42, and a cathode reaction area 43. The cathode cavity 20 and the anode cavity 21 are located on the plate surface near the side. The cathode reaction area 43 is located at the center of the plate surface. The cathode cavity 20 is connected to the cathode reaction area 43 through the cathode inlet / outlet 42 and the cathode distribution area 40. The cathode sealing area 41 is located at the edge of the entire cathode plate. The cathode gas can only enter the cathode plate 5 from the cathode cavity 20 through the cathode inlet / outlet channel 33 to the cathode inlet / outlet 42.

[0041] In this embodiment, both the anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3 are provided with a first support surface 36, a second support surface 37, a third support surface 38, a sealing area 35, an anode inlet / outlet gas channel 32, and a cathode inlet / outlet gas channel 33. The anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3 are each provided with a sealing area 35. When the anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3 are welded or bonded together, a sealed structure is formed. The first support surface 36 of the inlet / outlet gas channel plate is located at the anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3. At the outermost edge of the guide plate 3, the second support surface 37 of the inlet / outlet channel plate is located on the plate surface of the anode inlet / outlet channel plate 2 and the cathode inlet / outlet channel plate 3; the second support surface 37 of the inlet / outlet channel plate is provided with an anode inlet / outlet channel 32 and a cathode inlet / outlet channel 33; the first support surfaces 36 of the inlet / outlet channel plates on the anode inlet / outlet channel plate 2 and the cathode inlet / outlet channel plate 3 are attached together to form an outer welding line 30 between the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate; the second support surfaces 37 of the inlet / outlet channel plates on the anode inlet / outlet channel plate 2 and the cathode inlet / outlet channel plate 3 are attached together to form an inner welding line 31 between the anode inlet / outlet channel plate and the cathode inlet / outlet channel plate, so that the anode inlet / outlet channel 32 and the cathode inlet / outlet channel 3 on the anode inlet / outlet channel plate 2 and the cathode inlet / outlet channel plate 3 are interconnected.

[0042] Detailed explanation as follows: The first support surface 36 of the inlet / outlet gas channel plates of the anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3 are attached and welded together, such as... Figure 5 As shown, an outer welding line 30 is formed between the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate to prevent gas leakage. Similarly, the second support surfaces 37 of the inlet / outlet gas channel plates 2 and 3 of the anode inlet / outlet gas channel plate are attached, avoiding the anode inlet / outlet gas channel 32 and the cathode inlet / outlet gas channel 33, for internal welding. Figure 5As shown, a welding line 31 is formed on the inner side of the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate to prevent gas leakage. Two welding operations fix the anode inlet / outlet gas channel plate 2 and the cathode inlet / outlet gas channel plate 3 into a single unit, eliminating the need for sealing with a sealing strip as in traditional structures, resulting in more stable sealing performance. The anode sealing area 24 of the anode plate 1 and the cathode sealing area 41 of the cathode plate 5 are welded to the third support surface 38 of the inlet / outlet gas channel plate, thus forming a single unit from the anode plate 1, the anode inlet / outlet gas channel plate 2, the cathode inlet / outlet gas channel plate 3, and the cathode plate 5. It should be noted that the welding between the anode inlet / outlet gas channel plate and the anode plate forms a welding line 34; the welding between the cathode inlet / outlet gas channel plate and the cathode plate forms a welding line 39, as detailed below. Figure 8 As shown, the anode gas can only enter the anode plate 1 from the anode cavity 21 through the anode inlet / outlet channel 32, then to the anode inlet / outlet 25. Similarly, the cathode gas can only enter the cathode plate 5 from the cathode cavity 20 through the cathode inlet / outlet channel 33, then to the cathode inlet / outlet 42. Welding the anode sealing area 24 of the anode plate 1 and the cathode sealing area 41 of the cathode plate 5 to the third support surface 38 of the inlet / outlet channel plate not only solves the sealing problem between the anode plate 1, the cathode plate 5, and the anode / cathode inlet / outlet channel plates, but also provides gas field sealing support for the anode plate 1 and the cathode plate 5. The structure is simple and the sealing performance is reliable.

[0043] The upper and lower surfaces of the cooling heat sink 4 are composed of an array of N staggered rectangular structures. Each staggered rectangular structure runs through both the upper and lower surfaces of the heat sink. Each staggered rectangular structure on each surface has two heat dissipation vents. The four heat dissipation vents are arranged adjacent to each other and are interconnected, which greatly improves the convection efficiency of the heat sink. At the same time, the staggered structure acts as a reinforcing rib structure of the heat sink, which greatly improves the support strength of the heat sink. Compared with the traditional roll-formed fin structure, it has higher support strength and better heat dissipation efficiency.

[0044] Example 2

[0045] A method for preparing a closed-loop air-cooled metal bipolar plate includes the following steps:

[0046] 1) The first support surface 36 of the gas inlet and outlet channel plate 2 and the gas inlet and outlet channel plate 3 of the anode gas inlet and outlet channel plate 2 and the cathode gas inlet and outlet channel plate 3 are attached and welded together to form the outer welding line 30 of the anode gas inlet and outlet channel plate and the cathode gas inlet and outlet channel plate to prevent gas leakage.

[0047] 2) The second support surface 37 of the anode inlet and outlet gas channel plate 2 and the cathode inlet and outlet gas channel plate 3 are attached together and internal welding is performed to form the internal welding line 31 between the anode inlet and outlet gas channel plate and the cathode inlet and outlet gas channel plate to prevent gas leakage. The two weldings fix the anode inlet and outlet gas channel plate 2 and the cathode inlet and outlet gas channel plate 3 into a whole.

[0048] 3) The anode sealing area 24 of the anode plate 1 and the cathode sealing area (41) of the cathode plate 5 are welded to the third support surface 38 of the inlet and outlet air passage plate, respectively. The welding area of ​​the anode plate is as follows: Figure 6 As shown in Figure 26, the cathode plate bonding area is as follows. Figure 7 As shown in the welding line 44, the anode plate 1, the anode inlet and outlet gas channel plate 2, the cathode inlet and outlet gas channel plate 3, and the cathode plate 5 form a whole. The anode gas can only go from the anode cavity 21 through the anode inlet and outlet channel 32 to the anode inlet and outlet 25, and then enter the anode plate 1. Similarly, the cathode gas can only go from the cathode cavity 20 through the cathode inlet and outlet channel 33 to the cathode inlet and outlet 42, and then enter the cathode plate 5.

[0049] 4) such as Figure 2-1 As shown, the heat sink 4 needs to be fixed together with the anode plate 1 and the cathode plate 5 by welding. The boss and groove of the heat sink 4 are designed with multiple welding points A and B. The boss of the heat sink 4 is welded to the sealing area 24 of the anode plate 1, and the welding point position is shown as welding point A. The groove of the heat sink 4 is welded to the sealing area 41 of the cathode plate 5, and the welding point position is shown as welding point B.

[0050] like Figure 9 As shown, thanks to the heat dissipation structure in this application and the design of replacing the traditional rubber strip seal with welding at the cavity end, the heat dissipation capacity, sealing capacity, and overall rigidity of the electrode plate are significantly improved. Compared with the prior art, the polarization performance not only has a higher average single-plate voltage, but also a higher overall polarization density point. The performance is improved by at least 30%.

[0051] Existing closed-loop air-cooled bipolar plates mainly use two structures: 1. A traditional straight-through air inlet and outlet structure, which has the risk of seal failure due to only one side of the inner side being sealed and the need to rely on the flow channel and frame to build the seal support strength; 2. A layered air inlet and outlet structure that is similar to that of liquid cooling plates. Although the sealing performance is reliable, the plate utilization rate is not high, and two more sets of air inlet and outlet channel plates are required, resulting in higher costs. In addition, both of these traditional closed-loop air-cooled structures require sealing rings with a thickness equivalent to 4 cm of the cooling heat dissipation plate between the anode and cathode air inlet and outlet channel plates for sealing.

[0052] The above embodiments of the present invention are merely examples for clearly illustrating the present invention and are not intended to limit the implementation of the present invention. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively describe all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A closed-loop air-cooled metal bipolar plate, characterized in that, From top to bottom, they are anode plate (1), anode inlet and outlet air passage plate (2), cathode inlet and outlet air passage plate (3) and cathode plate (5); a cooling heat dissipation plate (4), anode inlet and outlet air passage plate (2) and cathode inlet and outlet air passage plate (3) are provided between the anode plate (1) and the cathode plate (5). The cooling heat dissipation plate (4) has a support surface on both the upper and lower sides; the support surface is composed of multiple staggered polygonal structures in an array, each staggered polygonal structure penetrates both the upper and lower sides of the heat dissipation plate, each staggered polygonal structure on each side has a heat dissipation port, the heat dissipation ports are arranged adjacently and are interconnected.

2. The closed-loop air-cooled metal bipolar plate as described in claim 1, characterized in that, The cooling heat dissipation plate (4) has a support surface on both the upper and lower sides; the support surface is composed of multiple staggered rectangular structures in an array, each staggered rectangular structure penetrates both the upper and lower sides of the heat dissipation plate, each staggered rectangular structure on each side has two heat dissipation holes, the four heat dissipation holes are arranged adjacently and are interconnected.

3. The closed-loop air-cooled metal bipolar plate as described in claim 1, characterized in that, The anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are attached and welded together through the first support surface (36) of the inlet / outlet gas channel plate.

4. The closed-loop air-cooled metal bipolar plate as described in claim 1, characterized in that, Both the anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are provided with a first support surface (36), a second support surface (37), a third support surface (38), an anode inlet / outlet gas channel (32), and a cathode inlet / outlet gas channel (33); wherein both the anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are provided with an inlet / outlet gas channel plate sealing area (35), which is formed when the anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are welded or bonded together. The first support surface (36) of the inlet and outlet air channel plate is located at the outermost edge of the anode inlet and outlet air channel plate (2) and the cathode inlet and outlet air channel plate (3), and the second support surface (37) of the inlet and outlet air channel plate is located on the plate surface of the anode inlet and outlet air channel plate (2) and the cathode inlet and outlet air channel plate (3); the anode inlet and outlet air channel (32) and the cathode inlet and outlet air channel (33) are provided on the second support surface (37) of the inlet and outlet air channel plate. The first support surface (36) of the inlet and outlet air channel plate on the anode inlet and outlet air channel plate (2) and the cathode inlet and outlet air channel plate (3) are attached and connected to form an outer welding line (30) between the anode inlet and outlet air channel plate and the cathode inlet and outlet air channel plate. The second support surface (37) of the anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are attached and connected to form an inner welding line (31) between the anode inlet / outlet gas channel plate and the cathode inlet / outlet gas channel plate, so that the anode inlet / outlet gas channel (32) and the cathode inlet / outlet gas channel (33) on the anode inlet / outlet gas channel plate (2) and the cathode inlet / outlet gas channel plate (3) are interconnected.

5. The closed-loop air-cooled metal bipolar plate as described in claim 1, characterized in that, The anode plate (1) is provided with a cathode cavity (20), an anode cavity (21), an anode reaction zone (22), an anode distribution zone (23), an anode sealing zone (24), and an anode inlet / outlet (25). The cathode cavity (20) and the anode cavity (21) are located on the plate surface near the side of the plate, and the anode reaction zone (22) is located at the center of the plate surface. The anode cavity (21) is connected to the anode reaction zone (22) through the anode inlet / outlet (25) and the anode distribution zone (23). The anode sealing zone (24) is located at the edge of the entire anode plate. The anode gas can only reach the anode inlet / outlet 25 from the anode cavity 21 through the anode inlet / outlet channel 32, and then enter the anode plate 1.

6. The closed-loop air-cooled metal bipolar plate as described in claim 1, characterized in that, The cathode plate (5) is provided with a cathode cavity (20), an anode cavity (21), a cathode distribution area (40), a cathode sealing area (41), a cathode inlet / outlet (42), and a cathode reaction area (43); the cathode cavity (20) and the anode cavity (21) are respectively located on the plate surface near the side; the cathode reaction area (43) is located at the center of the plate surface; the cathode cavity (20) is connected to the cathode reaction area (43) through the cathode inlet / outlet (42) and the cathode distribution area (40); the cathode sealing area (41) is located at the edge of the entire cathode plate; the cathode gas can only enter the cathode plate (5) from the cathode cavity (20) through the cathode inlet / outlet channel (33) to the cathode inlet / outlet (42).

7. A closed-loop air-cooled metal bipolar plate as described in claim 3, 4, or 5, characterized in that, The third support surface (38) of the air inlet and outlet channel plate is connected to the anode sealing area (24) of the anode plate (1) and the cathode sealing area (41) of the cathode plate (5), respectively.

8. The method for preparing the closed-loop air-cooled metal bipolar plate according to any one of claims 1 to 7, characterized in that, Includes the following steps: 1) The first support surface (36) of the inlet and outlet gas channel plate of the anode inlet and outlet gas channel plate (2) and the cathode inlet and outlet gas channel plate (3) are attached and welded to form the outer welding line (30) of the anode inlet and outlet gas channel plate and the cathode inlet and outlet gas channel plate to prevent gas leakage. 2) The second support surface (37) of the inlet and outlet gas channel plate of the anode inlet and outlet gas channel plate (2) and the cathode inlet and outlet gas channel plate (3) are attached together and internal welding is performed to form an internal welding line (31) between the anode inlet and outlet gas channel plate and the cathode inlet and outlet gas channel plate to prevent gas leakage. The two weldings fix the anode inlet and outlet gas channel plate (2) and the cathode inlet and outlet gas channel plate (3) into a whole. 3) The anode sealing area (24) of the anode plate (1) and the cathode sealing area (41) of the cathode plate (5) are welded to the third support surface (38) of the inlet and outlet gas channel plate, respectively. Thus, the anode plate (1), the anode inlet and outlet gas channel plate (2), the cathode inlet and outlet gas channel plate (3) and the cathode plate (5) form a whole. The anode gas can only go from the anode cavity (21) through the anode inlet and outlet channel (32) to the anode inlet and outlet (25) and then enter the anode plate (1). Similarly, the cathode gas can only go from the cathode cavity (20) through the cathode inlet and outlet channel (33) to the cathode inlet and outlet (42) and then enter the cathode plate (5). 4) The heat sink (4) needs to be fixed together with the anode plate (1) and the cathode plate (5) by welding. The boss and groove of the heat sink (4) are designed with multiple welding points. The boss of the heat sink (4) is welded to the sealing area (24) of the anode plate (1), and the groove of the heat sink (4) is welded to the sealing area (41) of the cathode plate (5).

Images