Long-service-life high-pressure-resistant PEM electrolytic bath sealing structure

Abstract

The invention provides a long-service-life high-pressure-resistant PEM electrolytic cell sealing structure. The long-service-life high-pressure-resistant PEM electrolytic cell sealing structure comprises a metal bipolar plate, a sealing rubber strip and a sealing electrode frame. The surfaces of the two sides of the metal bipolar plate are each provided with a circle of groove along the outer edge. The two sides of the metal bipolar plate are provided with the sealing rubber strips formed in the grooves in an injection molding mode respectively, and the sealing rubber strips on the two sides are connected to form an integrated structure. The surfaces of the two sides of the sealing pole frame are each provided with a plurality of circles of protruding edge hard sealing lines along the outer edge. And when the electrolytic bath is subjected to an assembly pressing force, the convex edge hard sealing line compresses the sealing rubber strip in contact with the convex edge hard sealing line, so that the sealing rubber strip is compressed below the horizontal plane of the upper edge of the groove. According to the technical scheme, it can be guaranteed that displacement, caused by thickness changes, of electrolytic cell parts is compensated in the long-time operation process of the electrolytic cell, and meanwhile the leakage risk caused by failure of soft sealing lines in the long-time operation process can be effectively avoided through the arranged sealing rubber lines.

Description

Technical Field

[0001] The invention relates to the technical field of proton exchange membrane (PEM) water electrolysis for hydrogen production, and in particular to a long-life high-pressure resistant PEM electrolyzer sealing structure. Background Art

[0002] PEM water electrolysis hydrogen production technology has been deeply developed and applied in large-scale demonstrations due to its unique technical advantages such as stable operation under high current density, the electrolyzer can directly produce ≥3MPa of hydrogen and fast transient response rate. PEM electrolyzer can directly produce high-pressure hydrogen at the hydrogen outlet, saving a lot of energy for subsequent hydrogen compression and storage. The production of high-pressure hydrogen is one of the main technical advantages of PEM electrolyzer. In order to achieve the output of high-pressure gas, the sealing structure design of PEM electrolyzer is particularly important. How to design a stable and reliable high-pressure electrolyzer sealing structure with a service life of more than 80,000 hours is the core content of PEM electrolyzer design.

[0003] At present, the design of most PEM electrolyzer sealing components is still based on the sealing design scheme of PEM fuel soft rubber wire as the sealing component. In order to achieve the sealing of higher pressure gas, the structure is optimized and improved. The rubber wire seal is a fully soft structure. Under the certain temperature of the electrolyzer and the pressure of the high-pressure medium inside, it is easy to age and cause leakage risks during long-term operation.

[0004] The second commonly used sealing structure is to add a pole frame sealing assembly, with a raised prism structure on the surface of the pole frame, and the high-pressure gas is sealed by pressing a soft thin sealing gasket through the prism. The raw materials for the pole frame are generally polyetheretherketone, polysulfone, polyphenylene sulfide, polyetherimide, etc. The sealing gasket is generally a PTFE film. Compared with the fully soft sealing structure, the thickness of the soft sealing structure is reduced. The pressure-bearing body is the pole frame structure. Compared with the soft sealing line, the pole frame structure has better tolerance and can ensure the long-term stable operation of the pressure-type electrolyzer. However, this structure still has the problem of thinner sealing gaskets producing creep or plastic deformation during long-term operation. The small rebound amount of the thin gasket is not enough to compensate for the displacement caused by the creep or plastic deformation of the gasket, which makes the electrolyzer leak. At the same time, the assembly of multi-layer gaskets increases the difficulty of assembly and is prone to misalignment. Summary of the invention

[0005] According to the technical problems existing in the rubber wire seal or pole frame structure seal adopted by the PEM electrolyzer sealing, a long-life high-pressure resistant PEM electrolyzer sealing structure is provided, which adopts the sealing concept of "soft and hard combination", and a concave groove is opened in the bipolar plate of the electrolyzer, and a through hole is penetrated in the groove. An integrated sealing strip is injection-molded in the grooves on both sides of the bipolar plate through the injection molding process, and the strips on both sides are connected as a whole through the through holes penetrated in the groove to prevent displacement of the strip structure; the sealing structure also includes a pole frame structure of the main sealing component, and a plurality of convex ridges are provided on the outer edge surface of the pole frame The hard sealing line structure, when subjected to the assembly force of the electrolytic cell, the ridges on the surface of the pole frame will compress the sealing strip structure injected on the bipolar plate, and the sealing strip will sink below the upper edge plane of the bipolar plate groove. The main pressure-bearing structure is the hard sealing pole frame, and the soft sealing strip is not exposed above the horizontal plane of the upper edge of the groove, making the sealing structure more reliable; the sealing strip has greater elastic deformation than the sealing film, and can effectively compensate for the changes in the thickness of the diffusion layer, the deformation of the sealing components, the creep, etc. during the long-term use of the electrolytic cell, so that it can achieve long-life stable operation under high temperature and high pressure conditions.

[0006] The technical means adopted by the present invention are as follows:

[0007] A long-life high-pressure resistant PEM electrolyzer sealing structure, comprising a metal bipolar plate, a sealing rubber strip and a sealing pole frame;

[0008] A circle of grooves are respectively provided along the outer edge of the two side surfaces of the metal bipolar plate, and through holes are provided in the grooves that penetrate the two side surfaces of the metal bipolar plate; the two sides of the metal bipolar plate are respectively provided with the sealing strips injection-molded in the grooves, and the sealing strips on both sides are connected to each other through the through holes during the injection molding process to form an integrated structure;

[0009] The two side surfaces of the sealing pole frame are respectively provided with multiple circles of convex ridge hard sealing lines along the outer edges corresponding to the positions of the sealing strips;

[0010] The electrolytic cell comprises two metal bipolar plates, a membrane electrode and two sealing pole frames; a group of metal bipolar plates and sealing pole frames are respectively arranged on both sides of the membrane electrode, and the convex ridge hard sealing line on the sealing pole frame is in contact with the sealing rubber strip on the metal bipolar plate on the same side;

[0011] When the electrolytic cell is subjected to the assembly compression force, the convex hard sealing line compresses the contacting sealing strip, so that the sealing strip is compressed to below the horizontal plane of the upper edge of the groove.

[0012] Furthermore, a thin film sealing gasket is installed between the outer edges of the two side surfaces of the membrane electrode and the sealing electrode frame, and the convex ridge hard sealing line on the sealing electrode frame is in contact with the thin film sealing gasket;

[0013] In the electrolytic cell, the two sealing pole frames located on the cathode side and the anode side of the membrane electrode are respectively the cathode sealing pole frame and the anode sealing pole frame; when the electrolytic cell is subjected to the assembly pressing force, the multiple circles of the convex ridge hard sealing lines on the surface of the cathode sealing pole frame and the anode sealing pole frame facing the membrane electrode can engage with each other to form a gap, and squeeze the thin film sealing gasket and the membrane electrode to deform and fill in the gap to form a seal.

[0014] Furthermore, in the electrolytic cell, a cathode carbon paper diffusion layer and an anode titanium felt diffusion layer are respectively provided on the cathode side and the anode side of the membrane electrode; the inner edges of the thin film sealing gasket on both sides of the membrane electrode overlap with the outer edges of the cathode carbon paper diffusion layer and the anode titanium felt diffusion layer respectively.

[0015] Furthermore, titanium meshes are provided between the cathode carbon paper diffusion layer and the metal bipolar plate located on the cathode side of the membrane electrode, and between the anode titanium felt diffusion layer and the metal bipolar plate located on the anode side of the membrane electrode.

[0016] Furthermore, the metal bipolar plate is a titanium-based metal plate or a stainless steel metal plate with a corrosion-resistant coating, and the forming process of the groove on the metal bipolar plate is an etching process, a machining process or a stamping process.

[0017] Furthermore, the thickness of the metal bipolar plate is 0.2-5 mm; the depth of the groove is 0.05-2 mm, and the width is 1-50 mm; and the diameter of the through hole is 0.2-25 mm.

[0018] Furthermore, the material of the sealing strip is EPDM rubber, silicone rubber or fluororubber.

[0019] Furthermore, the sealed pole frame is made of polyetheretherketone, polysulfone, polyphenylene sulfide or polyetherimide.

[0020] Furthermore, the molding process of the sealed pole frame is a machining process or an injection molding process.

[0021] Furthermore, the height of the convex ridge hard sealing line is 0.1-5 mm; the distance between two adjacent circles of the convex ridge hard sealing line is 1-10 mm.

[0022] Furthermore, the material of the thin film sealing gasket is polytetrafluoroethylene, polyetherimide, polyphenylene sulfide or polyimide, and the thickness of the thin sealing gasket is 10 to 100 μm.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. The long-life, high-pressure resistant PEM electrolyzer sealing structure provided by the present invention adopts a "soft and hard combination" sealing design concept, which can not only ensure that the displacement of the electrolyzer components caused by thickness changes during the long-term operation of the electrolyzer is compensated, but also the soft sealing line completely sunken in the groove of the bipolar plate can effectively avoid the risk of leakage caused by the failure of the soft sealing line during long-term operation.

[0025] 2. The long-life, high-pressure resistant PEM electrolyzer sealing structure provided by the present invention can simplify the difficulty of electrolyzer assembly. The one-piece injection-molded sealing strip structure reduces the use of independent sealing films and can effectively prevent installation dislocation caused by sliding of the soft sealing component, thereby simplifying the electrolyzer assembly process.

[0026] Based on the above reasons, the present invention can be widely promoted in the field of proton exchange membrane (PEM) water electrolysis hydrogen production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. 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 labor.

[0028] Figure 1 Schematic diagram of the anode side structure of the metal bipolar plate.

[0029] Figure 2 Schematic diagram of the cathode side structure of the metal bipolar plate.

[0030] Figure 3 Schematic diagram of the cathode sealing frame structure.

[0031] Figure 4 Schematic diagram of the anode sealing frame structure.

[0032] Figure 5 Schematic diagram of the cross-sectional structure of the electrolytic cell.

[0033] In the figure: 1. Metal bipolar plate; 2. Sealing strip; 3. Raised ridge hard sealing line; 4. Cathode sealing pole frame; 5. Anode sealing pole frame; 6. Cathode carbon paper diffusion layer; 7. Membrane electrode (MEA); 8. Thin film sealing gasket; 9. Anode titanium felt diffusion layer; 10. Titanium mesh; 11. Plate groove through-hole. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] 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 only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. 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.

[0036] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0037] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps described in these embodiments do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0038] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0039] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0040] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0041] like Figure 1-5 As shown, the present invention provides a long-life high-pressure resistant PEM electrolyzer sealing structure, comprising a metal bipolar plate 1, a sealing rubber strip 2 and a sealing pole frame;

[0042] A circle of grooves are respectively provided along the outer edge of the two side surfaces of the metal bipolar plate 1, and a through hole 11 is provided in the groove to penetrate the two side surfaces of the metal bipolar plate 1; the two sides of the metal bipolar plate 1 are respectively provided with the sealing strips 2 injection-molded in the grooves, and the sealing strips 2 on both sides are connected to each other through the through holes 11 during the injection molding process to form an integrated structure, which can enhance the firmness of the sealing strips 2, effectively increase the bonding force between the sealing strips 2 and the metal bipolar plate 1, and prevent the sealing strips 2 from displacement;

[0043] The two side surfaces of the sealing pole frame are respectively provided with multiple circles of convex ridge hard sealing lines 3 along the outer edges corresponding to the positions of the sealing strips 2;

[0044] The electrolytic cell comprises two metal bipolar plates 1 arranged opposite to each other on the cathode side and the anode side, a membrane electrode 7 and two sealing pole frames; a group of metal bipolar plates 1 and sealing pole frames are respectively arranged on both sides of the membrane electrode 7, and the convex hard sealing line 3 on the sealing pole frame is in contact with the sealing rubber strip 2 on the metal bipolar plate 1 located on the same side;

[0045] When the electrolytic cell is subjected to assembly compression force, the convex hard sealing line 3 compresses the contacting sealing strip 2, so that the sealing strip 2 is compressed to below the horizontal plane of the upper edge of the groove, so that the main pressure-bearing structure of the sealing structure is the hard sealing pole frame, and the soft sealing strip 2 is not exposed above the horizontal plane of the upper edge of the groove, thereby making the overall sealing structure more reliable.

[0046] Furthermore, a thin film sealing gasket 8 is installed between the outer edges of the two side surfaces of the membrane electrode 7 and the sealing electrode frame, and the convex ridge hard sealing line 3 on the sealing electrode frame is in contact with the thin film sealing gasket 8;

[0047] like Figure 5 As shown, in the electrolytic cell, the two sealing pole frames located on the cathode side and the anode side of the membrane electrode 7 are respectively the cathode sealing pole frame 4 and the anode sealing pole frame 5; when the electrolytic cell is subjected to the assembly pressing force, the multiple circles of the convex ridge hard sealing wires 3 on the surface of the cathode sealing pole frame 4 and the anode sealing pole frame 5 facing the membrane electrode 7 can mesh with each other to form a gap, and squeeze the thin film sealing gasket 8 and the membrane electrode 7 to deform and fill in the gap to form a seal, thereby achieving reliable sealing between the pole frame-membrane electrode-pole frame.

[0048] Furthermore, in the electrolytic cell, a cathode carbon paper diffusion layer 6 and an anode titanium felt diffusion layer 9 are respectively provided on the cathode side and the anode side of the membrane electrode 7; the inner edges of the thin film sealing gasket 8 on both sides of the membrane electrode 7 overlap with the outer edges of the cathode carbon paper diffusion layer 6 and the anode titanium felt diffusion layer 9 respectively, and when the electrolytic cell is subjected to assembly compression force, the thin film sealing gasket 8 can prevent the edges of the cathode carbon paper diffusion layer 6 and the anode titanium felt diffusion layer 9 from piercing the membrane electrode 7.

[0049] Furthermore, a titanium mesh 10 is provided between the cathode carbon paper diffusion layer 6 and the metal bipolar plate 1 located on the cathode side of the membrane electrode 7, and between the anode titanium felt diffusion layer 9 and the metal bipolar plate 1 located on the anode side of the membrane electrode 7, so as to disperse fluid / gas and transmit electrons between the cathode carbon paper diffusion layer 6 and the anode titanium felt diffusion layer 9 and the metal bipolar plate 1.

[0050] Furthermore, the metal bipolar plate 1 is a titanium-based metal plate or a stainless steel metal plate with a corrosion-resistant coating, and the forming process of the groove on the metal bipolar plate 1 is an etching process, a machining process or a stamping process.

[0051] Furthermore, the thickness of the metal bipolar plate 1 is 0.2-5 mm; the depth of the groove is 0.05-2 mm, and the width is 1-50 mm; the diameter of the through hole 11 is 0.2-25 mm.

[0052] Furthermore, the material of the sealing strip 2 can be raw materials or modified materials such as EPDM rubber, silicone rubber or fluororubber.

[0053] Furthermore, the sealed pole frame may be made of polyetheretherketone, polysulfone, polyphenylene sulfide, polyetherimide or other materials or modified materials thereof.

[0054] Furthermore, the molding process of the sealed pole frame is a machining process or an injection molding process.

[0055] Furthermore, the cross-sectional shape of the convex ridge hard sealing line 3 can be an arcuate surface, a trapezoidal surface, a rectangular surface or other special-shaped surfaces; the height of the convex ridge hard sealing line 3 is 0.1 to 5 mm; the distance between two adjacent circles of the convex ridge hard sealing line 3 is 1 to 10 mm.

[0056] Furthermore, the material of the thin film sealing gasket 8 is polytetrafluoroethylene, polyetherimide, polyphenylene sulfide or polyimide, and the thickness of the thin sealing gasket 8 is 10-100 μm.

[0057] The present invention adopts the design concept of "soft and hard combination", with the soft sealing strip as an elastic body and the convex ridge hard sealing line on the outer edge surface of the hard sealing pole frame as a hard structure. Under the action of the bolt assembly force, the convex ridge hard sealing line on the sealing pole frame can compress the soft sealing strip in the groove, causing the sealing strip to undergo elastic deformation, pressing the sealing strip down to below the horizontal plane of the upper edge of the groove, and multiple circles of convex ridge hard sealing lines will form a multiple circle line sealing structure with the sealing strip;

[0058] When subjected to the internal high-pressure gas medium pressure, the hard sealing pole frame acts as the main force carrier, and the sealing strip sunk into the groove will not be displaced due to the strong limiting effect of the groove, preventing the risk of leakage during long-term stable operation;

[0059] Another advantage of the sealing structure described in the present invention is that since the sealing strip injected on the metal bipolar plate is an elastomer with a certain elasticity, when the electrolytic cell has been running for a long time and some components have aged and caused the electrolytic cell structure to shift, the elastomer can compensate for the deviation displacement and reduce the risk of leakage; at the same time, the one-piece bipolar plate structure with a sealing strip can avoid the use of independent sealing gaskets, reduce the difficulty of assembly, and reduce the risk of leakage caused by assembly errors.

[0060] According to a long-life high-pressure resistant PEM electrolyzer sealing structure proposed in the present invention, the present invention will be described in detail in conjunction with Examples 1-3.

[0061] Example 1

[0062] In this embodiment, the metal bipolar plate 1 is a titanium-based metal plate, the thickness of the metal bipolar plate 1 is 2 mm, the groove is formed on the metal bipolar plate 1 by a machining process, the depth of the groove is 0.4 mm, the width is 7 mm, and the through holes 11 with a diameter of 2 mm and uniform distribution are arranged in the groove;

[0063] The injection molding process is adopted to inject the sealing strip 2 made of fluororubber into the groove of the metal bipolar plate 1. The thickness of the sealing strip 2 is 0.5 mm and the width is 7 mm. The compression rate of the sealing strip 2 under the assembly pressing force is 20%, and the sealing strip 2 is just fully embedded in the groove after compression deformation.

[0064] The material of the sealing pole frame is polyetheretherketone (PEEK), and the cathode sealing pole frame 4 and the anode sealing pole frame 5 and the convex ridge hard sealing line 3 with a height of 0.3 mm are processed from the PEEK plate by mechanical processing technology. The cross-sectional shape of the convex ridge hard sealing line 3 is an arc surface. The cathode sealing pole frame 4 is provided with three circles of the convex ridge hard sealing line 3, and the anode sealing pole frame 5 is provided with two circles of the convex ridge hard sealing line 3. The distance between the two circles of the convex ridge hard sealing line 3 is 3 mm;

[0065] The thickness of the thin film sealing gasket 8 is 50 μm;

[0066] By adjusting the thickness of the titanium mesh 10 , the sealing effect of the electrolytic cell can be ensured flexibly while the internal interface contact resistance of the electrolytic cell reaches an optimal value.

[0067] Example 2

[0068] The difference between this embodiment and embodiment 1 is only that:

[0069] The material of the sealing strip 2 is EPDM rubber; the molding process of the sealing pole frame is injection molding process; the material of the sealing pole frame is polyetherimide; the cross-sectional shape of the convex ridge hard sealing line 3 is a trapezoidal surface, the lower width is 1.4mm, the upper width is 1mm, and the distance between the two circles of the convex ridge hard sealing line 3 is 3mm; the size structure and processing technology of other components are the same as those in Example 1.

[0070] Example 3

[0071] The difference between this embodiment and embodiment 1 is only that:

[0072] The metal bipolar plate 1 is a titanium-based metal plate, and the thickness of the metal bipolar plate 1 is 3 mm. The metal bipolar plate 1 is etched with an etching process to form a groove with the same depth as the flow channel in the flow field area of ​​the metal bipolar plate 1. The depth of the flow channel and the groove in the flow field area of ​​the metal bipolar plate 1 is 0.5 mm. A silicone rubber sealing strip 2 with a thickness of 0.6 mm is injection molded in the groove of the metal bipolar plate 1, and the compression rate of the sealing strip 2 under the assembly pressing force is 20%; the size structure and processing technology of other components are the same as those in Example 1.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail 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 replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A long-life high-pressure resistant PEM electrolyzer sealing structure, characterized in that: It includes metal bipolar plates, sealing strips and sealing pole frames; A circle of grooves are respectively provided along the outer edge of the two side surfaces of the metal bipolar plate, and through holes are provided in the grooves that penetrate the two side surfaces of the metal bipolar plate; the two sides of the metal bipolar plate are respectively provided with the sealing strips injection-molded in the grooves, and the sealing strips on both sides are connected to each other through the through holes during the injection molding process to form an integrated structure; The two side surfaces of the sealing pole frame are respectively provided with multiple circles of convex ridge hard sealing lines along the outer edges corresponding to the positions of the sealing strips; The electrolytic cell comprises two metal bipolar plates, a membrane electrode and two sealing pole frames; a group of metal bipolar plates and sealing pole frames are respectively arranged on both sides of the membrane electrode, and the convex ridge hard sealing line on the sealing pole frame is in contact with the sealing rubber strip on the metal bipolar plate on the same side; When the electrolytic cell is subjected to the assembly compression force, the convex hard sealing line compresses the contacting sealing strip, so that the sealing strip is compressed to below the horizontal plane of the upper edge of the groove.

2. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 1, characterized in that: A thin film sealing gasket is installed between the outer edges of the two side surfaces of the membrane electrode and the sealing electrode frame, and the convex ridge hard sealing line on the sealing electrode frame is in contact with the thin film sealing gasket; In the electrolytic cell, the two sealing pole frames located on the cathode side and the anode side of the membrane electrode are respectively the cathode sealing pole frame and the anode sealing pole frame; when the electrolytic cell is subjected to the assembly pressing force, the multiple circles of the convex ridge hard sealing lines on the surface of the cathode sealing pole frame and the anode sealing pole frame facing the membrane electrode can engage with each other to form a gap, and squeeze the thin film sealing gasket and the membrane electrode to deform and fill in the gap to form a seal.

3. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 2, characterized in that: In the electrolytic cell, a cathode carbon paper diffusion layer and an anode titanium felt diffusion layer are respectively provided on the cathode side and the anode side of the membrane electrode; the inner edges of the thin film sealing gaskets on both sides of the membrane electrode overlap with the outer edges of the cathode carbon paper diffusion layer and the anode titanium felt diffusion layer respectively.

4. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 3 is characterized in that: Titanium meshes are provided between the cathode carbon paper diffusion layer and the metal bipolar plate located on the cathode side of the membrane electrode, and between the anode titanium felt diffusion layer and the metal bipolar plate located on the anode side of the membrane electrode.

5. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 1, characterized in that: The metal bipolar plate is a titanium-based metal plate or a stainless steel metal plate with a corrosion-resistant coating. The forming process of the groove on the metal bipolar plate is an etching process, a mechanical process or a stamping process; the forming process of the sealing pole frame is a mechanical process or an injection molding process.

6. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 1, characterized in that: The material of the sealing rubber strip is EPDM rubber, silicone rubber or fluororubber; the material of the sealing pole frame is polyetheretherketone, polysulfone, polyphenylene sulfide or polyetherimide.

7. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 1, characterized in that: The thickness of the metal bipolar plate is 0.2 to 5 mm; the depth of the groove is 0.05 to 2 mm, and the width is 1 to 50 mm; the diameter of the through hole is 0.2 to 25 mm; the height of the convex ridge hard sealing line is 0.1 to 5 mm; and the distance between two adjacent circles of the convex ridge hard sealing line is 1 to 10 mm.

8. The long-life high-pressure resistant PEM electrolyzer sealing structure according to claim 2, characterized in that: The material of the thin film sealing gasket is polytetrafluoroethylene, polyetherimide, polyphenylene sulfide or polyimide, and the thickness of the thin sealing gasket is 10-100 μm.

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