A PEM bipolar plate, cell and electrolyser

Abstract

The application discloses a PEM bipolar plate, a single cell and an electrolytic cell, and relates to the technical field of the electrolytic cell. The PEM bipolar plate comprises a square bipolar plate body. The middle part of one side of the bipolar plate body is concave to form an anode flow channel area. The middle part of the other side of the bipolar plate body is concave to form a cathode flow channel area. Two flow channel openings are arranged at intervals along the four sides of the bipolar plate body. In the application, water can enter the anode side and the cathode side of the bipolar plate body at the same time, and the water quantity is consistent. The application can maximize the conduction of heat, ensure the uniformity of the flow of the fluid in the flow channels on both sides, improve the hydrogen transmission efficiency, and ensure the electrolysis efficiency and working performance.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrogen production, and in particular to a PEM bipolar plate, a single cell and an electrolyzer. Background Art

[0002] As one of the important equipment for green hydrogen production, PEM (proton exchange membrane) electrolyzer has the advantages of compact structure, small footprint, high electrolysis efficiency, and the ability to obtain high-purity hydrogen under high-pressure conditions.

[0003] As one of the important components inside the PEM electrolyzer, the bipolar plate plays the role of uniformly transmitting and distributing reactants and products, collecting current, conducting electrons, conducting heat and controlling the temperature uniformity of the reaction zone. Therefore, it needs to have good electron transmission efficiency, thermal conductivity efficiency, excellent mechanical properties and a uniformly distributed flow field.

[0004] Existing bipolar plates, such as the one disclosed in patent number CN202311724840.8 and a PEM electrolyzer, have hydrogen and water flow channels within the bipolar plate body. The hydrogen flow channel connects the cathode side with the hydrogen outlet, while the water flow channel connects the anode side with the water inlet and outlet. Because water can only flow from one side, thermal conductivity is poor and hydrogen transmission efficiency is low, significantly impacting electrolysis efficiency and performance, making it unsuitable for large-plate, high-current-density electrolyzers. Summary of the Invention

[0005] The problem solved by the present invention is how to improve the thermal conductivity of the reaction zones on both sides of the bipolar plates and the hydrogen transmission efficiency, thereby ensuring the electrolysis efficiency and working performance to adapt to the application of electrolytic cells with large plates and high current density.

[0006] In a first aspect, the present invention provides a PEM bipolar plate comprising a square bipolar plate body, characterized in that:

[0007] The middle part of one side of the bipolar plate body is concave to form an anode flow channel area, and the middle part of the other side of the bipolar plate body is concave to form a cathode flow channel area. Two flow channel openings are arranged at intervals along the four sides of the bipolar plate body. The two flow channel openings near the lower right corner of the bipolar plate body are anode inlets, and the two flow channel openings near the upper left corner of the bipolar plate body are anode outlets. The inlet of the anode flow channel area is connected to the anode inlet on the right side of the lower end of the bipolar plate body, and the outlet of the anode flow channel area is connected to the anode outlet on the left side of the upper end of the bipolar plate body. The two flow channel openings near the lower left corner of the bipolar plate body are cathode inlets, and the two flow channel openings near the upper right corner of the bipolar plate body are cathode outlets. The inlet of the cathode flow channel area is connected to the cathode inlet at the lower end of the left side of the bipolar plate body, and the outlet of the cathode flow channel area is connected to the cathode outlet at the upper end of the right side of the bipolar plate body.

[0008] Preferably, the flow channels of the anode flow channel area are arranged in a vertical direction, and the flow channels of the cathode flow channel area are arranged in a horizontal direction. The along-the-path distance of the flow channels of the anode flow channel area is equal to the along-the-path distance of the flow channels of the cathode flow channel area, where the along-the-path distance refers to the length of the path along which the fluid flows along the flow channel.

[0009] Preferably, the flow channels in the anode flow channel area are parallel flow channels, and the flow channels in the anode flow channel area include vertical distribution flow channels on both sides and a first horizontal flow channel in the middle, and the vertical distribution flow channels are respectively connected to the anode inlet and the anode outlet, and the flow channels in the cathode flow channel area are parallel flow channels, and the flow channels in the cathode flow channel area include horizontal distribution flow channels at both ends, a middle vertical flow channel and a second horizontal flow channel, and the second horizontal flow channel is arranged between the two middle vertical flow channels, and the two middle vertical flow channels are also respectively connected to the two horizontal distribution flow channels, and the two horizontal distribution flow channels are also respectively connected to the cathode inlet and the cathode outlet.

[0010] Preferably, sealing grooves with the same structure are respectively provided on both sides of the bipolar plate body, and the sealing groove on one side of the bipolar plate body is 90° different from the sealing groove on the other side thereof. The sealing grooves include flow port sealing grooves provided around each of the flow port of the bipolar plate body and flow channel area sealing grooves provided on the periphery of the flow channel area, and matching sealing rubber lines are provided inside the flow port sealing grooves and the flow channel area sealing grooves.

[0011] Preferably, the flow channel areas on both sides of the bipolar plate body are processed by etching the flow channels.

[0012] Preferably, the flow channel openings are of the same size and symmetrically arranged, and the flow channel openings are semicircular.

[0013] In a second aspect, the present invention further provides a single cell comprising a PEM bipolar plate as described in any one of the first aspects above.

[0014] Preferably, it also includes a membrane electrode, a plurality of bipolar plates and a plurality of membrane electrodes are stacked at intervals, one of the bipolar plates is rotated 180° relative to another adjacent bipolar plate, and one of the membrane electrodes is rotated 90° relative to another adjacent membrane electrode, the anode side of the membrane electrode is connected to the anode side of one bipolar plate, and the cathode side of the membrane electrode is connected to the cathode side of another bipolar plate.

[0015] Preferably, two membrane electrode flow channel openings are provided on each of the four sides close to the membrane electrode, and the membrane electrode flow channel openings are arranged corresponding to the flow channel openings of the bipolar plate.

[0016] In a third aspect, the present invention provides an electrolytic cell comprising a single cell as described in the second aspect.

[0017] The beneficial effects of the PEM bipolar plate applied for in the present invention are: since the anode inlet of the anode flow channel area of ​​the bipolar plate body is at the lower right end of the bipolar plate body, and the anode outlet is at the upper left end of the bipolar plate body, the fluid flow direction on the anode side is from the lower right to the upper left, and the cathode inlet of the cathode flow channel area of ​​the bipolar plate body is at the lower left side of the bipolar plate body, and the cathode outlet is at the upper right side of the bipolar plate body, then the fluid flow direction on the cathode side is from the lower left to the upper right. The anode inlet and the cathode inlet of the bipolar plate body can be filled with water at the same time, and the water volume is kept consistent, which can not only maximize the heat conduction, but also ensure the flow uniformity of the flow channel fluid on both sides, improve the hydrogen transmission efficiency, and ensure the electrolysis efficiency and working performance.

[0018] The beneficial effects of the single cell and electrolyzer applied for by the present invention are: the bipolar plates and the membrane electrodes are arranged in a stacked manner with intervals, and at the same time, two adjacent bipolar plates are arranged 180° apart, and two adjacent membrane electrodes are arranged 90° apart. This makes the pressure distribution of the bipolar plates on both sides in contact with the membrane electrode more uniform, making the membrane electrode less susceptible to damage, extending the service life, and saving costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a side A view of the bipolar plate body of the present invention;

[0020] Figure 2 This is a side B view of the bipolar plate body of the present invention;

[0021] Figure 3 Application for this invention Figure 1 A schematic diagram of the structure at point a in the middle;

[0022] Figure 4 Application for this invention Figure 2 A magnified schematic diagram of the structure at point b in the middle;

[0023] Figure 5 An exploded view of a single bipolar plate body and a single membrane electrode stacked together for the present invention;

[0024] Figure 6 An exploded diagram of the stacked membrane electrode and bipolar plate of the present invention;

[0025] Figure 7 This is a cloud diagram of the pressure distribution in the flow channel on the B side of the bipolar plate body applied for by the present invention;

[0026] Figure 8 The pressure distribution cloud diagram of the B-side flow channel on both sides of the membrane electrode applied for by the present invention;

[0027] Figure 9This is a cloud diagram of the pressure distribution in the flow channel on the A side of the bipolar plate body applied for by the present invention;

[0028] Figure 10 The pressure distribution cloud diagram of the flow channel on the A side on both sides of the membrane electrode applied for by the present invention;

[0029] Description of reference numerals:

[0030] 1. Bipolar plate body; 2. Anode flow channel area; 21. Vertical distribution flow channel; 22. First horizontal flow channel; 3. Cathode flow channel area; 31. Horizontal distribution flow channel; 32. Second horizontal flow channel; 33. Middle vertical flow channel; 4. Anode inlet; 5. Cathode inlet; 6. Anode outlet; 7. Cathode outlet; 8. Sealing groove; 81. Flow channel sealing groove; 82. Flow channel area sealing groove; 9. Sealing glue line; 10. Membrane electrode; 11. Mounting hole; 12. Connection hole. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] Among them, the same parts are represented by the same figure marks. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings of the present application specification, and the words "bottom" and "top", "inside" and "outside" refer to directions toward or away from specific parts, respectively. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application specification, the meaning of "multiple" is two or more.

[0033] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0034] Example 1, as Figure 1 is the front view of the bipolar plate body, which is defined as the A side, such as Figure 2The figure shows a back view of the bipolar plate body, which is defined as the B side. A PEM bipolar plate provided in this embodiment includes a square bipolar plate body 1. The bipolar plate body 1 has two opposite side surfaces (i.e., side A and side B). The middle portion of one side surface of the bipolar plate body 1 is concave to form an anode flow channel region 2. The middle portion of the other side surface of the bipolar plate body 1 is concave to form a cathode flow channel region 3. Two flow channel openings are provided along each of the four sides of the bipolar plate body 1. The two flow channel openings near the lower right corner of the bipolar plate body 1 are anode inlets 4, and the two flow channel openings near the upper left corner of the bipolar plate body 1 are anode outlets 6. The inlet of the anode flow channel area 2 is connected to the anode inlet 4 on the right side of the lower end of the bipolar plate body 1, and the outlet of the anode flow channel area 2 is connected to the anode outlet 6 on the left side of the upper end of the bipolar plate body 1; the two flow channel openings near the lower left corner of the bipolar plate body 1 are the cathode inlet 5, and the two flow channel openings near the upper right corner of the bipolar plate body 1 are the cathode outlet 7. The inlet of the cathode flow channel area 3 is connected to the cathode inlet 5 at the lower end of the left side of the bipolar plate body 1, and the outlet of the cathode flow channel area 3 is connected to the cathode outlet 7 at the upper end of the right side of the bipolar plate body 1.

[0035] Since the bipolar plate body 1 of this embodiment is square and water can flow into the flow channels on both sides, during use, the anode side can be the A side or the B side of the bipolar plate body 1, and correspondingly, the cathode side can be the A side or the B side of the bipolar plate body 1. In this way, when stacked with the membrane electrode, it can be freely selected according to actual needs. Figure 1The A side of the bipolar plate body shown is defined as the anode side, and the B side is defined as the cathode side. The anode flow channel area 2 and the cathode flow channel area 3 on both sides of the bipolar plate body 1 are arranged in different ways. The fluid in the anode flow channel area 2 enters from the anode inlet 4 on the lower right side of the bipolar plate body 1, and then flows out from the anode outlet 6 on the upper left side of the bipolar plate body 1. The flow channel arrangement of the anode flow channel area 2 is vertical from bottom to top. The fluid in the cathode flow channel area 3 enters from the cathode inlet 5 at the lower end of the left side of the bipolar plate body 1, and then flows out from the cathode outlet 7 at the upper end of the right side of the bipolar plate body 1. The flow channel arrangement of the cathode flow channel area 3 is horizontal from left to right. Through the mutually perpendicular flow channel arrangement, compared with the existing bipolar plates, such as the bipolar plates, PEM electrolyzers, and PEM fuel cells disclosed in patent application number CN202411437587.2, Material batteries and new energy vehicles, the flow channel arrangement of the reaction zones on the anode side and the cathode side of the bipolar plate is the same, both using parallel flow channels arranged in the horizontal direction. At the same time, pure water can only enter the anode side, and only a hydrogen outlet is set on the cathode side, that is, the anode side is a water flow channel, and the cathode side is a hydrogen flow channel. Since it adopts a single-sided water inlet method, the thermal conductivity is poor, and the hydrogen transmission efficiency is not high. The electrolysis efficiency and performance are greatly affected. In this embodiment, the cathode inlet and the anode inlet of the bipolar plate body can realize a double-sided water inlet method, ensuring that the flow field maintains a low pressure drop during the operation of the electrolyzer, and at the same time has good thermal conductivity, which improves the hydrogen transmission efficiency, ensures the electrolysis efficiency and performance, and is more suitable for applications in large-plate, high-current-density electrolyzers.

[0036] Specifically, the bipolar plate of this embodiment adopts a double-sided water inlet method, that is, pure water enters the anode flow channel area 2 of the bipolar plate. After a small amount of pure water participates in the reaction, a large amount of other pure water carries oxygen and flows out from the anode outlet 6 of the anode flow channel area 2. Pure water also enters the cathode flow channel area 3 of the bipolar plate. This pure water does not participate in the electrolysis reaction, but can make the hydrogen in the reaction area on this side evenly distributed and the temperature evenly distributed, thereby improving the hydrogen transmission efficiency. In this way, water enters the flow channel areas on both sides of the bipolar plate at the same time, and the water volume on both sides is kept consistent, which can maximize heat conduction, control the temperature distribution of the reaction area, improve the gas transmission efficiency, and ensure the electrolysis efficiency and performance. It is especially suitable for electrolytic cells with large plate types and high electrical density.

[0037] Preferably, the bipolar plate body 1 can be made of titanium plate or stainless steel plate. In this embodiment, the bipolar plate body 1 is made of titanium plate, which is a whole plate. The outer side of the titanium plate is platinum-plated by PVD, and the flow channel areas on both sides are processed by etching flow channels. The thickness of the bipolar plate body 1 is 2mm~3mm.

[0038] Preferably, the flow channels of the anode flow channel area 2 are arranged in the vertical direction, and the flow channels of the cathode flow channel area 3 are arranged in the horizontal direction. The along-the-path distance of the flow channels of the anode flow channel area 2 is equal to the along-the-path distance of the flow channels of the cathode flow channel area 3, where the along-the-path distance refers to the length of the path along which the fluid flows along the flow channel, so that the pressure drop on both sides of the bipolar plate body is basically the same.

[0039] Specifically, the flow channels in the anode flow channel region 2 are arranged in parallel. This parallel flow channel design ensures a low pressure drop across the entire flow field during electrolytic cell operation, enhancing mass and heat transfer and increasing the reaction rate on the anode side. The flow channels in the anode flow channel region 2 include vertical distribution channels 21 on either side and a first horizontal flow channel 22 in the middle. The vertical distribution channels 21 on either side connect to the anode inlet 4 and anode outlet 6, respectively. The ratio of the number of flow channels in the first horizontal flow channel 22 to the number of flow channels in the vertical distribution channel 21 is 1:1 to 3:1. In this embodiment, as shown in Figure 3, which is an enlarged structural diagram of part of the flow channels in the anode flow channel area, it can be seen that the number of flow channels in the first horizontal flow channel 22 of the bipolar plate is three times the number of flow channels in the vertical distribution flow channels 21. Since the anode flow channel area 2 is used to transport pure water and oxygen generated by electrochemical reactions, and the number of flow channels in the first horizontal flow channel 22 is more than the number of vertical distribution flow channels 21, by increasing the number of parallel flow channels and existing in parallel, the contact area can be increased, the flow resistance can be reduced, the pressure loss can be reduced, and heat transfer can be promoted, the temperature can be kept stable during operation, and performance degradation due to local overheating can be avoided.

[0040] Specifically, the flow channel arrangement of the cathode flow channel area 3 adopts a parallel flow channel arrangement. The flow channels of the cathode flow channel area 3 include horizontal distribution flow channels 31 at both ends, an intermediate vertical flow channel 33 and a second horizontal flow channel 32. The second horizontal flow channel 32 is arranged between the two intermediate vertical flow channels 33. The two intermediate vertical flow channels 33 are also respectively connected to the two horizontal distribution flow channels 31. The two horizontal distribution flow channels 31 are respectively connected to the cathode inlet 5 and the cathode outlet 7. Among them, the horizontal distribution flow channel 31 and the flow channels of the intermediate vertical flow channels 33 are connected one by one, and the connection between the flow channels of the horizontal distribution flow channel 31 and the flow channels of the intermediate vertical flow channels 33 is connected through an arc flow channel. The number of flow channels of the second horizontal flow channel 32 and the number of flow channels of the intermediate vertical flow channel 33 are 3:1~1:1, and the flow channel connection between the second horizontal flow channel 32 and the intermediate vertical flow channel 33 is connected through an arc flow channel. In this embodiment, as Figure 4It can be seen from the enlarged structural diagram of part of the flow channels in the cathode flow channel area that the number of flow channels of the second horizontal flow channel 32 is three times the number of flow channels of the middle vertical flow channel 33. The cathode flow channel area 3 is used to transport pure water and hydrogen. Since the number of flow channels of the second horizontal flow channel 32 is more than the number of the middle vertical flow channel 33, the contact area can be increased by increasing the number of parallel flow channels and existing in parallel, which reduces the flow resistance and pressure loss, promotes heat transfer, maintains the temperature of the electrolytic cell stable during operation, and avoids performance degradation due to local overheating.

[0041] Since the along-the-path distance of the flow channel in the anode flow channel region 2 is equal to the along-the-path distance of the flow channel in the cathode flow channel region 3, although the flow channel in the cathode flow channel region 3 (side B) of the bipolar plate body 1 has two more bends than the flow channel in the anode flow channel region 2 (side A), the equal along-the-path distances result in a very small pressure drop, thereby making the pressure drops of the flow channels in the anode flow channel region (side A) and the cathode flow channel region (side B) basically the same.

[0042] Preferably, the flow openings provided on the bipolar plate body 1 include two anode inlets 4, two anode outlets 6, two cathode inlets 5, and two cathode outlets 7. The flow openings are of the same size and are symmetrically arranged. The flow openings can adopt circular, elongated, square and other structures. In this embodiment, the flow openings are arranged to be semicircular, so as to ensure uniform pressure at the mouth during sealing and ensure sealing.

[0043] Preferably, if Figure 5 From the exploded view of the single bipolar plate body and the single membrane battery stacked together, it can be seen that sealing grooves 8 are respectively provided on both sides of the bipolar plate body 1. The sealing grooves 8 on both sides have exactly the same structure, and the sealing groove 8 on one side of the bipolar plate body 1 is 90° apart from the sealing groove 8 on the other side of the bipolar plate body 1. Since the bipolar plate body 1 is a square structure and the flow channel openings thereon are of the same size and symmetrically arranged, the sealing glue lines on both sides thereof are also 90° apart. During use, the anode flow channel area 2 and the cathode flow channel area 3 of the bipolar plate body 1 can be defined according to actual conditions, that is, the anode flow channel area 2 on the A side can be defined as the cathode side flow channel area, or it can be defined as the anode flow channel area, and the same applies to the B side.

[0044] Specifically, the sealing grooves 8 include flow port sealing grooves 81 circumferentially located at each flow port (i.e., anode inlet 4, cathode inlet 5, anode outlet 6, and cathode outlet 1) of each bipolar plate body 1, and flow channel region sealing grooves 82 circumferentially located at the flow channel region (anode flow channel region 2 or cathode flow channel region 3). Matching sealant lines 9 are located within the flow port sealing grooves 81 and flow channel region sealing grooves 82. Each of the flow port sealing grooves 81 and flow channel region sealing grooves 82 is provided with spaced-apart raised strips. The sealant lines 9 are arranged within these sealing grooves, employing a double layer of sealant line. Short strips connect the openings of the corresponding raised strips between the two layers of sealant line. This not only ensures a good seal and prevents risks such as air leakage, but also maintains a tight seal even if any layer of the double layer of sealant line is damaged. At the same time, the sealing groove 8 on one side of the bipolar body 1 is 90° apart from the sealing groove 8 on the other side of the bipolar plate body 1. This setting is to ensure uniform pressure distribution when stacked with the membrane electrode, which will be described in detail in the following single cell.

[0045] Example 2: This example provides a single cell, including the above-mentioned PEM bipolar plate. Its advantages are the same as those of the PEM bipolar plate, which will not be repeated here.

[0046] Preferably, it also includes a membrane electrode 10, a plurality of bipolar plates and a plurality of membrane electrodes 10 are stacked at intervals, one bipolar plate is rotated 180° relative to another adjacent bipolar plate, and one membrane electrode 10 is rotated 90° relative to another adjacent membrane electrode 10. For each membrane electrode 10, the anode side of the membrane electrode 10 is connected to the anode side of one bipolar plate, and the cathode side of the membrane electrode 10 is connected to the cathode side of another bipolar plate.

[0047] Specifically, if Figure 6 Shown is an exploded view of two membrane electrode stacked with three bipolar plates. The three bipolar plates in the figure are named as bipolar plate No. 1, bipolar plate No. 2, and bipolar plate No. 3 from left to right, and the two membrane electrodes are named as membrane electrode No. 1 and membrane electrode No. 2 from left to right. At the same time, the fluid flow direction of the bipolar plates in the figure is indicated, the solid arrow is the fluid flow direction on the front of the bipolar plate, and the dotted arrow is the fluid flow direction on the back of the bipolar plate. It can be seen from the structure of the above-mentioned bipolar plate that the two side surfaces of the bipolar plate can be arbitrarily selected as the anode side and the other side as the cathode side as needed. When a single cell is stacked, the cathode side of membrane electrode No. 1 is connected to the cathode side (B side) of bipolar plate No. 1, the anode side of membrane electrode No. 1 is connected to the anode side (B side) of bipolar plate No. 2, the cathode side of membrane electrode No. 2 is connected to the cathode side (A side) of bipolar plate No. 2, and the anode side of membrane electrode No. 2 is connected to the anode side (A side) of bipolar plate No. 3, wherein bipolar plate No. 2 is rotated 180° relative to bipolar plate No. 1, and membrane electrode No. 2 is rotated 90° relative to membrane electrode No. 1.

[0048] During the stacking process of the membrane electrode, its anode side is connected to the anode side of one bipolar plate, and its cathode side is connected to the cathode side of another bipolar plate. Since the flow field arrangements of the anode and cathode sides of the existing bipolar plates are different and water can only enter one side, the anode side is a water flow channel, while the cathode side is generally a hydrogen channel. Therefore, the pressure on the membrane electrode in different areas is different, which makes the stress distribution of the membrane electrode uneven during use. The membrane electrode is prone to cracks, breakage and other defects in the areas where pressure is concentrated. These defects will gradually expand with the increase of usage time, eventually leading to the failure of the membrane electrode and shortening the service life of the electrolyzer.

[0049] In this embodiment 2, it can be seen from this arrangement that: for the cathode side of membrane electrode No. 1, the fluid flow direction of the cathode side (B side) of bipolar plate No. 1 in contact therewith is horizontally from the lower left to the upper right thereof; for the anode side of membrane electrode No. 1, the fluid flow direction of the anode side (B side) of bipolar plate No. 2 in contact therewith is horizontally from the lower right to the upper left thereof, as shown in FIG. Figure 7 The following is a cloud diagram showing the pressure distribution of the flow channel on the B side of the bipolar plate body. Figure 8 As shown, when both sides of the No. 1 membrane electrode are bipolar plate B-side flow channels (the membrane electrode is not shown), the pressure distribution cloud diagram on both sides shows that the pressure on the No. 1 membrane electrode is uniform; for the cathode side of the No. 2 membrane electrode, the fluid flow direction on the cathode side (A side) of the No. 2 bipolar plate in contact with it is vertically from the lower left to the upper right, and for the anode side of the No. 2 membrane electrode, the fluid flow direction on the anode side (A side) of the No. 2 bipolar plate in contact with it is vertically from the lower right to the upper left, as shown in FIG. Figure 9 The following is a cloud diagram of the pressure distribution of the flow channel on the A side of the bipolar plate body. Figure 10 The pressure distribution cloud diagram on both sides of the membrane electrode No. 1 shows that the pressure on the membrane electrode No. 2 is uniform. In summary, by adopting the single-cell stacking arrangement in Example 2 and the different flow channel forms on the A and B sides of the bipolar plates, the pressure at the same position on both sides of a single membrane electrode is approximately consistent, thereby preventing the membrane electrode from being punctured by excessive pressure differentials and effectively extending the service life of the membrane electrode 10. At the same time, the bipolar plates on both sides of the membrane electrode are either the A side or the B side at the same time, and the membrane electrode is rotated at a corresponding angle (90° rotation). This allows the glue lines on both sides of the membrane electrode to be completely aligned, ensuring a good sealing effect.

[0050] Preferably, mounting holes 11 are provided at the four corners of the bipolar plate body 1, and corresponding connection holes 12 are provided at the corresponding positions of the membrane electrode 10. Through the corresponding connection between the mounting holes 11 and the connection holes 12, the bipolar plate body 1 and the membrane electrode 10 are conveniently assembled, thereby improving the assembly accuracy.

[0051] Example 3: This example provides an electrolytic cell including the above-mentioned single cell. Its advantages are the same as those of the PEM bipolar plate and single cell, which will not be repeated here.

[0052] The above description is merely a preferred embodiment of the present invention, and the present invention is not limited to the above embodiments. It is understood that other improvements and variations directly derived or imagined by those skilled in the art without departing from the spirit and concept of the present invention should be considered to be included in the scope of protection of the present invention.

[0053] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as limiting the present invention itself. Various changes may be made to the form and details without departing from the spirit and scope of the present invention as defined in the appended claims.

Claims

1. A single cell comprising a PEM bipolar plate, wherein the bipolar plate comprises a square bipolar plate body, characterized in that: The middle part of one side of the bipolar plate body is concave to form an anode flow channel area, and the middle part of the other side of the bipolar plate body is concave to form a cathode flow channel area. Two flow channel openings are arranged at intervals along the four sides of the bipolar plate body. The two flow channel openings near the lower right corner of the bipolar plate body are anode inlets, and the two flow channel openings near the upper left corner of the bipolar plate body are anode outlets. The inlet of the anode flow channel area is connected to the anode inlet on the right side of the lower end of the bipolar plate body, and the outlet of the anode flow channel area is connected to the anode outlet on the left side of the upper end of the bipolar plate body. The two flow channel openings near the lower left corner of the bipolar plate body are cathode inlets, and the two flow channel openings near the upper right corner of the bipolar plate body are cathode outlets. The inlet of the cathode flow channel area is connected to the cathode inlet at the lower end of the left side of the bipolar plate body, and the outlet of the cathode flow channel area is connected to the cathode outlet at the upper end of the right side of the bipolar plate body. The flow channels of the anode flow channel region are arranged in a vertical direction, and the flow channels of the cathode flow channel region are arranged in a horizontal direction. The along-path distance of the flow channels of the anode flow channel region is equal to the along-path distance of the flow channels of the cathode flow channel region, where the along-path distance refers to the length of the path along which the fluid flows; Multiple bipolar plates and multiple membrane electrodes are stacked at intervals, wherein one of the bipolar plates is rotated 180° relative to another adjacent bipolar plate, and one of the membrane electrodes is rotated 90° relative to another adjacent membrane electrode, the anode side of the membrane electrode is connected to the anode side of one bipolar plate, and the cathode side of the membrane electrode is connected to the cathode side of another bipolar plate.

2. A single pool according to claim 1, characterized in that: The flow channels in the anode flow channel area are parallel flow channels, and the flow channels in the anode flow channel area include vertical distribution flow channels on both sides and a first horizontal flow channel in the middle, and the vertical distribution flow channels are respectively connected to the anode inlet and the anode outlet, and the flow channels in the cathode flow channel area are parallel flow channels, and the flow channels in the cathode flow channel area include horizontal distribution flow channels at both ends, a middle vertical flow channel and a second horizontal flow channel, and the second horizontal flow channel is arranged between the two middle vertical flow channels, and the two middle vertical flow channels are also respectively connected to the two horizontal distribution flow channels, and the two horizontal distribution flow channels are also respectively connected to the cathode inlet and the cathode outlet.

3. A single pool according to claim 2, characterized in that, Sealing grooves of the same structure are respectively provided on both sides of the bipolar plate body. The sealing groove on one side of the bipolar plate body is 90° different from the sealing groove on the other side. The sealing grooves include flow port sealing grooves provided around each of the flow port of the bipolar plate body and flow channel area sealing grooves provided on the periphery of the flow channel area. Matching sealing glue lines are provided inside the flow port sealing grooves and the flow channel area sealing grooves.

4. A single pool according to claim 3, characterized in that: The flow channel areas on both sides of the bipolar plate body are processed by etching the flow channels.

5. A single pool according to claim 4, characterized in that: The flow channel openings are of the same size and symmetrically arranged, and the flow channel openings are semicircular.

6. A single pool according to claim 5, characterized in that: Two membrane electrode flow channel openings are arranged at intervals on the four sides close to the membrane electrode, and the membrane electrode flow channel openings are arranged corresponding to the flow channel openings of the bipolar plate.

7. An electrolytic cell, characterized in that: A single cell comprising any one of claims 1 to 6.

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