Sealed bipolar plate of proton exchange membrane electrolytic cell

Abstract

The invention discloses a proton exchange membrane electrolytic cell sealing bipolar plate, which belongs to the technical field of water electrolysis hydrogen production, and comprises a bipolar plate body, a water inlet, a water / oxygen outlet, a first hydrogen outlet, a second hydrogen outlet, a water / oxygen flow field area, a hydrogen flow field area, an anode closed sealing groove and an anode sealing ring, the first hydrogen outlet, the water / oxygen outlet, the second hydrogen outlet and the water inlet are positioned at the edge of the bipolar plate body and are through holes; the first hydrogen outlet and the second hydrogen outlet are diagonally arranged; the water inlet and the water / oxygen outlet are diagonally arranged; a water / oxygen flow field area is arranged on the anode surface of the bipolar plate body; a hydrogen flow field area is arranged on the cathode surface of the bipolar plate body; the anode closed sealing groove is formed in the anode surface of the bipolar plate body; and an anode sealing ring is arranged in the anode closed sealing groove. The water / oxygen flow field area and the hydrogen flow field area are optimally designed, so that water flow can be more uniformly distributed, and gas flow is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of hydrogen production by electrolysis of water, and in particular relates to a sealed bipolar plate for a proton exchange membrane electrolyzer. Background Art

[0002] PEM (proton exchange membrane) water electrolysis is one of the main technical routes for producing green hydrogen. Compared with alkaline water electrolysis, PEM water electrolysis has the advantages of high current density, high hydrogen purity, and fast response speed. As a core device, the PEM electrolyzer must withstand the test of high pressure, high temperature and strong oxidation environment. As a key component of the electrolyzer, the bipolar plate undertakes multiple tasks of supporting the diffusion layer, conducting electricity, conducting heat, and transmitting gas and water. The realization of all these functions depends on a good sealing environment to ensure long-term stable operation.

[0003] As the "skeleton" of the electrolyzer, the bipolar plate plays an important role in the electrolysis process. However, the existing bipolar plate design of PEM electrolyzers has some shortcomings, especially in terms of sealing performance. Common problems include internal hydrogen and oxygen gas mixing, external leakage of hydrogen, etc., which will affect the safety and efficiency of the electrolyzer. In addition, under high assembly pressure, the sealing rings at the intersection of the sealing grooves are easily squeezed out and damaged by stress concentration in these areas. This stress concentration phenomenon can cause the sealing ring to deform, resulting in uneven contact resistance between the membrane electrode assembly and the bipolar plate, which in turn affects the electrolysis efficiency and may cause displacement of the membrane electrode assembly. Drying often occurs diagonally in the flow field area or hydrogen gathers to form a dead zone. This uneven distribution of water / oxygen two-phase flow and hydrogen flow in the flow field area will cause local high temperature and increased contact resistance inside the bipolar plate, thereby reducing the service life and electrolysis efficiency of the bipolar plate. Summary of the invention

[0004] In view of the above problems, the present invention discloses a sealed bipolar plate for a proton exchange membrane electrolyzer, comprising: a bipolar plate body, a water inlet, a water / oxygen outlet, a first hydrogen outlet, a second hydrogen outlet, a water / oxygen flow field area, a hydrogen flow field area, an anode closed sealing groove and an anode sealing ring;

[0005] The first hydrogen outlet, water / oxygen outlet, second hydrogen outlet and water inlet are located at the edge of the bipolar plate body and are all through holes; the first hydrogen outlet and the second hydrogen outlet are arranged diagonally; the water inlet and the water / oxygen outlet are arranged diagonally;

[0006] A water / oxygen flow field area is provided on the anode surface of the bipolar plate body;

[0007] A hydrogen flow field area is provided on the cathode surface of the bipolar plate body;

[0008] The anode closing sealing groove is arranged on the anode surface of the bipolar plate body;

[0009] The first hydrogen outlet and the second hydrogen outlet are provided with an anode closed sealing groove at the periphery thereof;

[0010] The water inlet, the water / oxygen flow field area and the periphery of the water / oxygen outlet are provided with anode closed sealing grooves;

[0011] An anode sealing ring is arranged in the anode closed sealing groove.

[0012] Furthermore, it also includes: a water inlet guide groove and a water outlet / oxygen outlet guide groove;

[0013] A plurality of water inlet guide grooves are provided between the water inlet and the water / oxygen flow field area;

[0014] A plurality of water / oxygen outlet guide grooves are arranged between the water / oxygen outlet and the water / oxygen flow field area.

[0015] Furthermore, the water / oxygen flow field region includes a water / oxygen main flow field and a water / oxygen secondary flow field;

[0016] The water / oxygen flow field area is rectangular as a whole;

[0017] Water / oxygen secondary flow fields are respectively arranged above and below the water / oxygen primary flow field;

[0018] The water / oxygen mainstream field is in the shape of a parallelogram as a whole;

[0019] The water / oxygen secondary flow field is in the shape of a right triangle as a whole.

[0020] Furthermore, the water / oxygen mainstream flow field includes a plurality of longitudinal guide grooves;

[0021] The width of the longitudinal guide groove is in the range of 0.5-5 mm;

[0022] The spacing between the longitudinal guide grooves is in the range of 0.5-5 mm;

[0023] The ratio of the total width of the longitudinal guide groove to the width of the water / oxygen flow field area is in the range of 1:1.3-2.

[0024] Furthermore, the water / oxygen secondary flow field includes a plurality of cylinders arranged in a lattice;

[0025] The angle between the long right-angle side and the hypotenuse of the water / oxygen secondary flow field is in the range of 10-30°.

[0026] Furthermore, the depths of the hydrogen flow field region, the water / oxygen flow field region, the water inlet guide groove and the water / oxygen outlet guide groove are in the range of 0.1-1 mm.

[0027] Furthermore, it also includes: a cathode closed sealing groove and a cathode sealing ring;

[0028] The cathode closed sealing groove is arranged on the cathode surface;

[0029] A plurality of strip-shaped protrusions are arranged on one side of the cathode sealing ring away from the bipolar plate body;

[0030] The peripheries of the water inlet and the water / oxygen outlet are both provided with cathode closed sealing grooves;

[0031] A cathode closed sealing groove is arranged at the periphery of the first hydrogen outlet, the second hydrogen outlet and the hydrogen flow field area;

[0032] A cathode sealing ring is arranged in the cathode closed sealing groove.

[0033] Furthermore, the cross-sections of the anode sealing ring and the cathode sealing ring are both rectangular, with a compression rate of 8-30%, and a filling rate of 60-90% for the closed sealing groove.

[0034] Furthermore, the anode closed sealing groove and the cathode closed sealing groove are both rectangular in cross-section, with a depth of 0.1-1 mm and a width of 1-10 mm.

[0035] Furthermore, it also includes: fastener holes and positioning holes;

[0036] A plurality of fastener holes are arranged around the edges of the bipolar plate body;

[0037] Positioning holes are arranged at the four corners of the bipolar plate body.

[0038] Compared with the prior art, the embodiments of the present invention have at least the following advantages:

[0039] 1) The three closed sealing grooves on one side become three independent sealing areas, and there are two sealing rings between the three adjacent sealing areas, which effectively avoids the potential leakage and gas mixing risks caused by the intersection of the sealing grooves in the traditional sealing structure, especially the safety hazards caused by the mixing of hydrogen and oxygen;

[0040] 2) The three closed sealing grooves on one side constitute independent sealing areas, with no junction between them, effectively avoiding the use of traditional T-shaped lap seals; this structure avoids damage to traditional seals due to stress concentration under high assembly pressure, thereby preventing uneven contact resistance between the membrane electrode assembly and the bipolar plate, and extending the service life of the seal and the bipolar plate; by ensuring that the seal is evenly compressed, the present invention not only achieves consistency in contact resistance, but also improves electrolysis efficiency while maintaining high sealing performance;

[0041] 3) One side of the cathode sealing ring is provided with strip-shaped protrusions, which are arranged alternately in peak and valley shapes. The peak and valley shapes of the protrusions help to form a tighter and irregular wavy sealing contact surface when the assembly is under pressure, effectively reducing the risk of gas leakage through the sealing surface between the sealing ring and the membrane electrode frame membrane, thereby further improving the sealing reliability of the electrolyzer;

[0042] 4) Fastener holes are set between the first hydrogen outlet and the water / oxygen outlet, and between the water inlet and the second hydrogen outlet. The electrolyzer is fastened by bolts, thereby ensuring the sealing effect between the ports and effectively preventing gas and liquid leakage. In addition, by adding positioning holes and combining the fastening effect of bolts, the assembly efficiency and sealing performance of the electrolyzer are significantly improved;

[0043] 5) The design of the bipolar plate adopts a perfect central symmetric structure, with the anode and cathode surfaces being completely identical in structure, eliminating the need to distinguish between the front and back sides during assembly, thereby simplifying the assembly process. This symmetry not only improves the convenience of assembly, but also reduces the complexity of the processing process, thereby reducing production costs and facilitating the mass production of bipolar plates; through this design, the versatility and production efficiency of the electrolyzer components are improved while maintaining cost-effectiveness;

[0044] 6) Optimizing the design of the water / oxygen flow field area and the hydrogen flow field area can distribute the water flow more evenly, effectively avoid local high temperature phenomena, enhance gas flow, and reduce dead zones, thereby ensuring the uniform distribution of the water / oxygen two-phase flow and hydrogen flow in the flow field area, thereby improving the service life and electrolysis efficiency of the bipolar plate.

[0045] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of the structure of the anode surface of a bipolar plate according to an embodiment of the present invention is shown;

[0048] Figure 2 A schematic diagram of the cathode surface structure of a bipolar plate according to an embodiment of the present invention is shown;

[0049] Figure 3 A schematic diagram of a closed sealing groove and a sealing ring combination of a bipolar plate according to an embodiment of the present invention is shown;

[0050] Figure 4 It shows a schematic structural diagram of a sealing ring before and after pressing according to an embodiment of the present invention;

[0051] Figure 5 A schematic diagram of overlapping anode and cathode sealing rings according to an embodiment of the present invention is shown.

[0052] Reference numerals: 1, bipolar plate body; 2, water inlet; 3, water / oxygen outlet; 4, first hydrogen outlet; 5, fastener hole; 6, positioning hole; 7, primer glue; 8, membrane electrode frame film; 9, second hydrogen outlet;

[0053] 11. Anode surface; 12. Water inlet guide groove; 13. Water / oxygen outlet guide groove; 14. Water / oxygen flow field area; 141. Water / oxygen main flow field; 142. Water / oxygen secondary flow field; 15. Anode closed sealing groove; 16. Anode sealing ring;

[0054] 21. Cathode surface; 22. Cathode closed sealing groove; 23. Cathode sealing ring; 231. Strip-shaped protrusion; 24. Hydrogen flow field area. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0056] Figure 1 FIG. 2 shows a schematic diagram of the structure of the anode surface of a bipolar plate according to an embodiment of the present invention. Figure 1 As shown, a sealed bipolar plate for a proton exchange membrane electrolyzer proposed in the present invention comprises: a bipolar plate body 1, a water inlet 2, a water / oxygen outlet 3, a first hydrogen outlet 4, a second hydrogen outlet 9, a water / oxygen flow field region 14, a hydrogen flow field region 24, an anode closed sealing groove 15 and an anode sealing ring 16;

[0057] The bipolar plate body 1 is configured to be in the shape of a flat rectangular parallelepiped, and its two end surfaces are respectively an anode surface 11 and a cathode surface 21 .

[0058] The first hydrogen outlet 4, the water / oxygen outlet 3, the second hydrogen outlet 9 and the water inlet 2 are located at the edge of the bipolar plate body 1; and they are all through holes; the first hydrogen outlet 4 and the second hydrogen outlet 9 are arranged diagonally, wherein the second hydrogen outlet 9 is adjacent to the water inlet 2, and the first hydrogen outlet 4 is adjacent to the water / oxygen outlet 3; the water inlet 2 and the water / oxygen outlet 3 are arranged diagonally to achieve effective use of space and optimization of the process;

[0059] Exemplarily, the first hydrogen outlet 4 is located at the upper left corner of the bipolar plate body 1 ; the water / oxygen outlet 3 is located at the upper right corner of the bipolar plate body 1 ; the second hydrogen outlet 9 is located at the lower right corner of the bipolar plate body 1 ; and the water inlet 2 is located at the lower left corner of the bipolar plate body 1 .

[0060] The water inlet 2 , the water / oxygen outlet 3 , the first hydrogen outlet 4 and the second hydrogen outlet 9 are all holes penetrating the bipolar plate body 1 , and are preferably rectangular in structure.

[0061] The anode surface 11 is provided with a water inlet 2, a water / oxygen flow field area 14, a water / oxygen outlet 3, a first hydrogen outlet 4, a second hydrogen outlet 9 and an anode closed sealing groove 15 arranged around each peripheral area. The water inlet 2, the water / oxygen flow field area 14 and the water / oxygen outlet 3 are arranged around an anode closed sealing groove 15 around the peripheral area, and the two hydrogen outlets are arranged around each peripheral area, a total of three independent closed sealing grooves, and there is no junction between them. The anode closed sealing groove 15 is provided on the anode surface 11. An anode sealing ring 16 is provided in the anode closed sealing groove 15.

[0062] The sealed bipolar plate of the proton exchange membrane electrolyzer also includes: a water inlet guide groove 12 and a water outlet / oxygen outlet guide groove 13;

[0063] The water inlet 2 is connected to the water / oxygen flow field area 14 through the water inlet guide groove 12 , and the water / oxygen outlet 3 is connected to the water / oxygen flow field area 14 through the water / oxygen outlet guide groove 13 .

[0064] The cathode surface 21 is provided with a first hydrogen outlet 4, a hydrogen flow field region 24, a second hydrogen outlet 9, a water inlet 2, a water / oxygen outlet 3 and a cathode closed sealing groove 22 arranged around each peripheral region. The cathode closed sealing groove 22 is provided on the cathode surface 21. The two hydrogen outlets are respectively connected to the hydrogen flow field region 24.

[0065] The water inlet 2 and the water / oxygen outlet 3 are both provided with a cathode closed sealing groove 22 at the periphery;

[0066] A cathode closed sealing groove 22 is arranged around the first hydrogen outlet 4, the second hydrogen outlet 9 and the hydrogen flow field area 24;

[0067] A cathode sealing ring 23 is arranged in the cathode closed sealing groove 22. The three cathode closed sealing grooves 22 are all independent sealing areas and have no intersections with each other.

[0068] After adopting the bipolar plate of the present invention, each independent closed sealing groove has two adjacent grooves for placing sealing rings. This structure can effectively prevent hydrogen and oxygen from permeating each other in the case of poor sealing, thereby reducing the risk of gas mixing and explosion. The three closed sealing grooves on each side constitute an independent sealing area, and there is no junction between them, which effectively avoids the use of traditional T-shaped lap seals. This structure avoids damage to traditional sealing rings due to stress concentration under high assembly pressure, thereby preventing uneven contact resistance between the membrane electrode assembly and the bipolar plate. By ensuring that the sealing ring is evenly compressed, the present invention not only achieves consistency in contact resistance, but also improves electrolysis efficiency while maintaining high sealing performance.

[0069] like Figure 1 and Figure 2 As shown, the water / oxygen flow field area 14 is composed of a water / oxygen main flow field 141 and two water / oxygen side flow fields 142 .

[0070] The water / oxygen flow field area 14 is rectangular in shape as a whole;

[0071] A water / oxygen secondary flow field 142 is respectively arranged above and below the water / oxygen primary flow field 141;

[0072] The water / oxygen mainstream field 141 is generally in the shape of a parallelogram;

[0073] The water / oxygen secondary flow field 142 is in the shape of a right triangle as a whole.

[0074] The water / oxygen mainstream field 141 includes a plurality of longitudinal guide grooves;

[0075] The width of the longitudinal guide groove is in the range of 0.5-5 mm; for example, the width of the longitudinal guide groove is 2 mm;

[0076] The spacing between the longitudinal guide grooves is in the range of 0.5-5 mm; for example, the spacing between the longitudinal guide grooves is 2 mm;

[0077] The ratio of the total width of the longitudinal guide groove to the width of the water / oxygen flow field area 14 is in the range of 1:1.3-2. Exemplarily, the ratio of the total width of the longitudinal guide groove to the width of the water / oxygen flow field area 14 is 1:2.

[0078] The water / oxygen secondary flow field 142 includes a plurality of cylinders arranged in a lattice pattern;

[0079] The angle between the long right-angled side and the hypotenuse of the water / oxygen auxiliary flow field 142 is in the range of 10-30°. For example, the angle between the long right-angled side and the hypotenuse of the water / oxygen auxiliary flow field 142 is 15°.

[0080] The depth of the hydrogen flow field region 24, the water / oxygen flow field region 14, the water inlet guide groove 12 and the water / oxygen outlet guide groove 13 ranges from 0.1 to 1 mm. Exemplarily, the depth of the hydrogen flow field region 24, the water / oxygen flow field region 14, the water inlet guide groove 12 and the water / oxygen outlet guide groove 13 is 0.5 mm.

[0081] The present invention optimizes the design of the water / oxygen flow field area 14 and the hydrogen flow field area 24, and uses longitudinal guide grooves and lattice cylinders to distribute the water flow more evenly, effectively avoid local high temperature phenomena, enhance gas flow, and reduce dead zones, thereby ensuring the uniform distribution of the water / oxygen two-phase flow and the hydrogen flow in the flow field area, thereby improving the service life and electrolysis efficiency of the bipolar plate.

[0082] The water / oxygen flow field area 14 is used for the anode reaction, and the hydrogen flow field area 24 is used for the cathode reaction. The water inlet 2 is used for water inlet, the water inlet guide groove 12 is used for the preliminary diversion of water, the water / oxygen flow field area 14 is used for the uniform transmission of water and the place where oxygen is produced by the anode reaction, and the water / oxygen outlet 3 is used for the discharge of water and oxygen. The hydrogen flow field area 24 is the place where hydrogen is produced by the cathode reaction, and the two hydrogen outlets are used for the discharge of hydrogen.

[0083] like Figure 3 and Figure 5 As shown, the projection positions of part of the anode closed sealing groove 15 and part of the cathode closed sealing groove 22 on the cross section of the bipolar plate body 1 are the same, and the cross sections of the closed sealing grooves are both rectangular structures. The anode sealing ring 16 and the cathode sealing ring 23 are respectively placed in the corresponding anode closed sealing groove 15 and cathode closed sealing groove 22, and are bonded and fixed to the closed sealing grooves by means of primer 7, thereby ensuring the stability of the sealing rings.

[0084] Furthermore, the cross-sections of the anode sealing ring 16 and the cathode sealing ring 23 are also rectangular, with a compression rate of 8-30%, and a filling rate of the closed sealing groove (the ratio of the cross-sectional area of ​​the sealing ring to the cross-sectional area of ​​the closed sealing groove) of 60-90%. These parameters ensure the proper compression and sealing effect of the sealing ring in the closed sealing groove. In particular, the cathode sealing ring 23 is provided with two strip-shaped protrusions 231 on the side away from the bipolar plate body 1. These protrusions are peak-shaped and valley-shaped, which increase the irregularity of the sealing contact surface, thereby forming a tighter seal during pressing, effectively reducing the risk of leakage.

[0085] The cross-sections of the anode closing sealing groove 15 and the cathode closing sealing groove 22 are both rectangular, with a depth of 0.1-1 mm and a width of 1-10 mm.

[0086] Figure 4 (a) is a schematic diagram before compression; Figure 4 (b) is a schematic diagram after compression. Figure 4 As shown in (a), the sealing unit is composed of a bipolar plate body 1, an anode sealing ring 16, a membrane electrode frame membrane 8, a cathode sealing ring 23, and a bipolar plate body 1 on the other side. By adding strip-shaped protrusions 231 to the cathode sealing ring 23, these protrusions are arranged alternately in peak and valley shapes. The peak and valley shapes of the protrusions help to form a more compact and irregular wavy sealing contact surface (such as Figure 4 (b) shows), which effectively reduces the risk of gas leakage through the sealing surface between the sealing ring and the membrane electrode frame membrane 8, thereby further improving the sealing reliability of the electrolytic cell.

[0087] In some embodiments, the material of the sealing ring can be selected from rubber materials such as fluororubber, EPDM rubber, silicone rubber, etc. In this embodiment, the material of the sealing ring is EPDM rubber, which can meet the sealing performance requirements of the PEM electrolyzer under a pressure of 5MPa. The production of the sealing ring can be achieved through laser cutting technology or mold opening technology to manufacture a sealing ring of the designed specifications. Both methods have their own advantages, and the most suitable manufacturing process can be selected according to production requirements, cost-effectiveness and design complexity of the sealing ring to ensure that the quality and performance of the sealing ring meet the requirements of specific applications.

[0088] In some embodiments, the bipolar plate body 1 is made of metal, and titanium or stainless steel can be used. These metal materials not only have good mechanical properties, but also have excellent electrical and thermal conductivity. In order to further enhance the corrosion resistance of the bipolar plate and prevent rapid corrosion during the electrochemical reaction, a protective coating is provided on the surface of the bipolar plate body 1. The optional coating materials include gold, platinum or composite materials. In terms of processing technology, the metal bipolar plate can be processed by precision processes such as stamping or etching to ensure the accuracy and quality of the bipolar plate.

[0089] like Figure 1 and Figure 2 As shown, a plurality of fastener holes 5 are evenly distributed at the edge of the bipolar plate body 1. The function of these fastener holes 5 is to fix the stacked bipolar plates in the electrolytic cell and ensure the sealing of each electrolytic chamber by compressing the sealing ring.

[0090] Furthermore, a fastener hole 5 is provided between the water inlet 2 and the second hydrogen outlet 9, which ensures the sealing effect between the water inlet 2 and the second hydrogen outlet 9, and effectively prevents the leakage of gas and liquid. A fastener hole 5 is provided between the first hydrogen outlet 4 and the water / oxygen outlet 3, which ensures the sealing effect between the first hydrogen outlet 4 and the water / oxygen outlet 3, and effectively prevents the leakage of gas and liquid.

[0091] The bipolar plate body 1 is also provided with positioning holes 6, and four positioning holes 6 are respectively arranged at the four corners of the bipolar plate body 1. The positioning holes 6 are used to facilitate the alignment between the bipolar plates to be stacked when the bipolar plates are stacked for electrolytic cell assembly, which effectively improves the positioning accuracy and efficiency of the electrolytic cell assembly.

[0092] It should be noted that the cathode surface 21 and the anode surface 11 of the bipolar plate body 1 have the same structural design. Therefore, no additional explanation is given for the structure of the cathode surface 21 in this embodiment. The design of the bipolar plate adopts a perfect central symmetrical structure, and its anode surface 11 and cathode surface 21 are completely identical in structure, eliminating the need to distinguish between the front and back sides during the assembly process, thereby simplifying the assembly process. This symmetry not only improves the convenience of assembly, but also reduces the complexity of the processing process, thereby reducing production costs and facilitating the mass production of bipolar plates; through this design, while maintaining cost-effectiveness, the versatility and production efficiency of the electrolytic cell assembly are improved.

[0093] It should be noted that, among the various structures in the bipolar plate body 1, the parts that require rounding can all be processed with rounded corners, and the present invention does not make special explanations therefor.

[0094] By optimizing the bipolar plate design, the present invention can effectively improve the performance of the electrolyzer and enhance its tolerance under high pressure, high temperature and strong oxidation environment, thereby achieving more efficient, safer and more stable green hydrogen production.

[0095] The working process of the sealed bipolar plate of the proton exchange membrane electrolyzer of the present invention is described as follows: the two end faces of the bipolar plate body 1 are the anode face 11 and the cathode face 21, respectively. The anode face 11 is provided with a water / oxygen flow field area 14 for electrolyzing water and generating oxygen. The two ends of the water / oxygen flow field area 14 are provided with a water inlet 2 and a water / oxygen outlet 3 for entering water and discharging oxygen from the water / oxygen flow field area 14; the position corresponding to the anode face 11 on the cathode face 21 is provided with a hydrogen flow field area 24, which is used to receive the protons generated after the anode face 11 electrolyzes water. These protons are transferred to the cathode face 21 through the proton exchange membrane, and react to generate hydrogen there. The cathode face 21 is provided with hydrogen outlets at both ends of the hydrogen flow field area 24 for discharging hydrogen.

[0096] In summary, the embodiment of the present invention provides a sealed bipolar plate for a proton exchange membrane electrolyzer, which realizes independent regional division by closing the sealing groove, effectively avoiding the potential leakage and gas mixing risks caused by the intersection of the sealing grooves in the traditional sealing structure. Combined with the precise matching between the bipolar plate grooves and the sealing ring and the membrane electrode assembly, not only the reliability of the seal is guaranteed under high pressure environment, but also the uniform distribution of the contact resistance between the bipolar plate and the porous diffusion layer is achieved, thereby improving the efficiency and safety of the electrolyzer.

[0097] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sealed bipolar plate for a proton exchange membrane electrolyzer, characterized in that: include: A bipolar plate body (1), a water inlet (2), a water / oxygen outlet (3), a first hydrogen outlet (4), a second hydrogen outlet (9), a water / oxygen flow field region (14), a hydrogen flow field region (24), an anode closed sealing groove (15) and an anode sealing ring (16); The first hydrogen outlet (4), the water / oxygen outlet (3), the second hydrogen outlet (9) and the water inlet (2) are located at the edge of the bipolar plate body (1) and are all through holes; the first hydrogen outlet (4) and the second hydrogen outlet (9) are arranged diagonally; the water inlet (2) and the water / oxygen outlet (3) are arranged diagonally; A water / oxygen flow field area (14) is provided on the anode surface (11) of the bipolar plate body (1); A hydrogen flow field area (24) is provided on the cathode surface (21) of the bipolar plate body (1); The anode closing sealing groove (15) is arranged on the anode surface (11) of the bipolar plate body (1); Anode closing sealing grooves (15) are arranged around the first hydrogen outlet (4) and the second hydrogen outlet (9); The water inlet (2), the water / oxygen flow field area (14) and the water / oxygen outlet (3) are provided with an anode closed sealing groove (15) at the periphery; An anode sealing ring (16) is arranged in the anode closed sealing groove (15).

2. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 1, characterized in that: It also includes: a water inlet guide groove (12) and a water outlet / oxygen outlet guide groove (13); A plurality of water inlet guide grooves (12) are arranged between the water inlet (2) and the water / oxygen flow field area (14); A plurality of water / oxygen outlet guide grooves (13) are arranged between the water / oxygen outlet (3) and the water / oxygen flow field area (14).

3. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 2, characterized in that: The water / oxygen flow field region (14) includes a water / oxygen main flow field (141) and a water / oxygen secondary flow field (142); The water / oxygen flow field region (14) is rectangular in shape as a whole; Water / oxygen secondary flow fields (142) are respectively arranged above and below the water / oxygen primary flow field (141); The water / oxygen mainstream field (141) is in the shape of a parallelogram as a whole; The water / oxygen secondary flow field (142) is in the shape of a right triangle as a whole.

4. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 3, characterized in that: The water / oxygen mainstream field (141) comprises a plurality of longitudinal guide grooves; The width of the longitudinal guide groove is in the range of 0.5-5 mm; The spacing between the longitudinal guide grooves is in the range of 0.5-5 mm; The ratio of the total width of the longitudinal guide groove to the width of the water / oxygen flow field area (14) is in the range of 1:1.3-2.

5. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 3 or 4, characterized in that: The water / oxygen secondary flow field (142) includes a plurality of circular columns arranged in a lattice pattern; The angle between the long right-angle side and the hypotenuse of the water / oxygen secondary flow field (142) is in the range of 10-30°.

6. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 3, characterized in that: The depths of the hydrogen flow field region (24), the water / oxygen flow field region (14), the water inlet guide groove (12) and the water / oxygen outlet guide groove (13) are in the range of 0.1-1 mm.

7. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 1, characterized in that: It also includes: a cathode closed sealing groove (22) and a cathode sealing ring (23); The cathode closed sealing groove (22) is arranged on the cathode surface (21); A plurality of strip-shaped protrusions (231) are provided on a side of the cathode sealing ring (23) away from the bipolar plate body (1); The water inlet (2) and the water / oxygen outlet (3) are both provided with cathode closed sealing grooves (22) at their peripheries; A cathode closed sealing groove (22) is arranged around the first hydrogen outlet (4), the second hydrogen outlet (9) and the hydrogen flow field area (24); A cathode sealing ring (23) is arranged in the cathode closed sealing groove (22).

8. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 7, characterized in that: The cross-sections of the anode sealing ring (16) and the cathode sealing ring (23) are both rectangular, with a compression rate of 8-30% and a filling rate of 60-90% for the closed sealing groove.

9. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 8, characterized in that: The anode closed sealing groove (15) and the cathode closed sealing groove (22) are both rectangular in cross section, with a depth of 0.1-1 mm and a width of 1-10 mm.

10. The sealed bipolar plate for a proton exchange membrane electrolyzer according to claim 1, characterized in that: Also includes: Fastener holes (5) and positioning holes (6); A plurality of fastener holes (5) are arranged on the edges around the bipolar plate body (1); Positioning holes (6) are provided at the four corners of the bipolar plate body (1).

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