Integrated sealing structure of PEM electrolytic bath and PEM electrolytic bath

Abstract

The integrated sealing structure comprises a polar plate assembly, a membrane electrode assembly and an integrated sealing body, the polar plate assembly comprises two bipolar plates, and the surfaces of the two sides of each bipolar plate are each provided with at least one annular sealing groove; the integrated sealing body is clamped between the two bipolar plates and is arranged along the periphery of the membrane electrode assembly in a sealing manner, the cross section of the integrated sealing body comprises a flat sealing main body, and one side surface of the sealing main body is provided with at least one first line sealing part and at least one first surface sealing part; and at least one second line sealing part and at least one second surface sealing part are arranged on the other side, the first line sealing part and the second line sealing part respectively abut against the corresponding annular sealing grooves in a sealing manner, and the first surface sealing part and the second surface sealing part respectively abut against the surfaces of the two bipolar plates in a sealing manner. According to the invention, linear sealing and surface sealing are combined, the sealing force under high pressure is enhanced, the clamping force is reduced, and the lateral displacement risk is effectively prevented.

Description

Technical Field

[0001] This invention relates to the field of PEM electrolysis for hydrogen production technology, and particularly to an integrated sealing structure and a PEM electrolyzer. Background Technology

[0002] PEM electrolyzers face significant challenges when operating under high and ultra-high pressures, placing immense strain on the sealing materials. Some manufacturers opt for surface sealing with gaskets, which requires high flatness of the electrode plates. Furthermore, the clamping force increases exponentially with increasing sealing pressure. Other manufacturers employ line sealing with sealing rings, which effectively reduces the clamping force. However, with rising sealing pressure, the sealing rings are prone to lateral displacement, risking being squeezed out of the sealing groove. Summary of the Invention The purpose of this invention is to provide an integrated sealing structure for a PEM electrolytic cell and a PEM electrolytic cell, which integrates the functions of a traditional outer frame and sealing structure, and can simultaneously provide a combination of line sealing and surface sealing. This enhances the sealing force under high pressure while reducing clamping force, effectively preventing the risk of lateral displacement, thereby solving one or more technical problems existing in the prior art, and at least providing a beneficial option or creating conditions.

[0003] The technical solution adopted to solve the above-mentioned technical problems is as follows: This invention provides an integrated sealing structure for a PEM electrolyzer, comprising: The electrode assembly includes two bipolar plates, each of which has at least one annular sealing groove on both sides. A membrane electrode assembly is sandwiched between the two bipolar plates; An integrated sealing body, having an annular structure, is an insulating component. It is sandwiched between two bipolar plates and sealed around the perimeter of the membrane electrode assembly. The cross-section of the integrated sealing body includes a flat sealing body. One side surface of the sealing body has at least one first line sealing portion with a raised structure and at least one first surface sealing portion with a planar structure. The other side surface has at least one second line sealing portion with a raised structure and at least one second surface sealing portion with a planar structure. The first and second surface sealing portions are positioned correspondingly in the thickness direction. The first and second line sealing portions respectively seal against the annular sealing grooves on the two bipolar plates, and the first and second surface sealing portions respectively seal against the surfaces of the two bipolar plates.

[0004] The advantages of the integrated sealing structure of the present invention are: This invention uses an integrated sealing body to seal between two bipolar plates and around the membrane electrode assembly, integrating the functions of a traditional outer frame and sealing structure. Simultaneously, the two side surfaces of the integrated sealing body respectively abut against the annular sealing grooves on the two bipolar plates through a first and second line sealing portion to achieve line sealing, and the two side surfaces of the integrated sealing body respectively abut against the surfaces of the two bipolar plates through a first and second surface sealing portion to achieve surface sealing. This invention combines line sealing and surface sealing, complementing the advantages and disadvantages of both, enhancing the sealing force under high pressure while reducing clamping force, effectively preventing lateral displacement risks, and exhibiting high integration, increasing assembly convenience. It integrates the traditional two installation processes of the outer frame and sealing ring into a single installation process of the integrated sealing body.

[0005] As a further improvement to the above technical solution, the inner edge of one side surface of the integrated sealing body is provided with an annular stepped groove. The membrane electrode assembly includes a cathode diffusion layer, a proton membrane, and an anode diffusion layer that are sequentially bonded together. The periphery of the proton membrane and the anode diffusion layer extends to the stepped groove. The periphery of the proton membrane is sealed and clamped between the anode diffusion layer and the stepped groove. The cathode diffusion layer is located in the inner ring of the integrated sealing body.

[0006] As a further improvement to the above technical solution, the first line sealing part and the cathode diffusion layer are located on the same side, and the integrated sealing body is provided with the first line sealing part at the position opposite to the stepped groove.

[0007] As a further improvement to the above technical solution, there are two first line sealing parts, one of which is located at the end of the sealing body away from the stepped groove, and the other is located at the end of the sealing body close to the stepped groove. The first surface sealing part is located between the two first line sealing parts.

[0008] As a further improvement to the above technical solution, the first line sealing portion and the second line sealing portion located at the end of the sealing body away from the stepped groove are positioned correspondingly in the thickness direction.

[0009] As a further improvement to the above technical solution, the proton exchange membrane and the stepped groove are connected by adhesive.

[0010] As a further improvement to the above technical solution, the edges of both sides of the proton membrane are provided with thin borders.

[0011] As a further improvement to the above technical solution, the integrated sealing body is made of one or more of silicone rubber, EPDM rubber and fluororubber, and the hardness of the integrated sealing body is greater than 70 Shore A.

[0012] As a further improvement to the above technical solution, the integrated sealing body is injection molded into one of the bipolar plates.

[0013] The present invention also proposes a PEM electrolytic cell, including the aforementioned integrated sealing structure.

[0014] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments; Figure 1 This is an exploded view of an embodiment of the integrated sealing structure provided by the present invention, showing the direct hot-pressing film electrode assembly and the integrated sealing body. Figure 2 This is an assembly diagram of the integrated sealing structure provided by the present invention, showing the direct hot-pressing film electrode assembly and the integrated sealing body in one embodiment. Figure 3 This is a schematic diagram of an embodiment of the sealing body provided by the present invention; Figure 4 This is an exploded view of an embodiment of the integrated sealing structure provided by the present invention, showing the dispensing hot-pressing film electrode assembly and the integrated sealing body. Figure 5 This is an assembly diagram of the integrated sealing structure provided by the present invention, showing the dispensing hot-pressing film electrode assembly and the integrated sealing body in one embodiment. Icon labels: Membrane electrode assembly 100; cathode diffusion layer 110; proton exchange membrane 120; anode diffusion layer 130; thin frame 140; Integrated sealing body 200; sealing main body 210; first line sealing part 211; first surface sealing part 212; second line sealing part 213; second surface sealing part 214; stepped groove 220; Cathode plate 300; Anode plate 400; 500mm annular sealing groove. Detailed Implementation

[0016] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0017] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0018] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0019] In the description of this invention, unless otherwise explicitly defined, terms such as "set up," "install," and "connect" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0020] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0021] Hydrogen production through water electrolysis is considered an effective approach for large-scale industrial hydrogen production due to its green, zero-emission energy technology advantages. PEM (Polymerized Electric Electrolysis) water electrolysis hydrogen production technology, with its compact structure, small footprint, high electrolysis efficiency, high-pressure extraction of high-purity hydrogen, and good compatibility with renewable energy sources, has become a focus of industry attention.

[0022] Currently, large-scale PEM (Potentially Oxide Membrane Electrolysis) water electrolysis equipment generally produces hydrogen at relatively low pressures, typically at atmospheric pressure, with a few below 3 MPa. However, hydrogen requires considerably higher pressures for transportation and end-use applications. For example, applications such as natural gas pipeline injection, green methanol production, and ammonia production require high-pressure hydrogen of 7-20 MPa, while hydrogen storage and transportation, as well as fuel cell vehicles, demand pressures as high as 35-70 MPa. Such high pressures necessitate the use of reciprocating compressors to pressurize the hydrogen produced by water electrolysis. This not only dramatically increases energy consumption for hydrogen production but also, as the compressor is a power source, adds complexity and unreliability to the hydrogen production system. Therefore, developing PEM water electrolysis technology for direct high-pressure hydrogen production can not only improve system efficiency and reduce energy consumption but also simplify the high-pressure hydrogen production system and reduce costs.

[0023] Electrolytes operating under high and ultra-high pressures place significant demands on their sealing materials. Existing sealing gasket structures either employ surface sealing or line sealing methods. Surface sealing requires high flatness of the electrode plates, and the clamping force increases exponentially with increasing sealing pressure. While line sealing effectively reduces clamping force, it carries the risk of lateral displacement and extrusion from the sealing groove as sealing pressure rises. Therefore, a stable sealing structure design for electrolytes, especially differential pressure PEM electrolyzers, under high pressure is a pressing issue that needs to be addressed.

[0024] Reference Figures 1-5 The integrated sealing structure of the PEM electrolytic cell of the present invention is illustrated in the following embodiment: like Figure 1 and Figure 2 As shown, the integrated sealing structure of the present invention includes: an electrode assembly, a membrane electrode assembly 100, and an integrated sealing body 200.

[0025] The electrode assembly includes two bipolar plates, such as... Figure 2 As shown, at least one annular sealing groove 500 is provided on both sides of the bipolar plate. The two bipolar plates in this embodiment include a cathode plate 300 and an anode plate 400.

[0026] The membrane electrode assembly 100 of the present invention is sandwiched between the cathode plate 300 and the anode plate 400.

[0027] The integrated sealing body 200 in this embodiment has a ring-shaped structure. Specifically, the shape of the integrated sealing body 200 is determined according to the shape of the membrane electrode assembly 100. The membrane electrode assembly 100 has a rectangular structure, and the integrated sealing body 200 in this embodiment is a rectangular ring-shaped structure.

[0028] In this embodiment, the integrated sealing body 200 is sandwiched between the cathode plate 300 and the anode plate 400. The integrated sealing body 200 is sealed around the membrane electrode assembly 100. The integrated sealing body 200 is an insulating component to prevent leakage between the single-chamber cathode plate 300 and the anode plate 400, replacing the existing outer frame.

[0029] like Figure 3 As shown, the cross-section of the integrated sealing body 200 in this embodiment includes a flat sealing body 210. One side surface of the sealing body 210 is provided with at least one first line sealing portion 211 with a raised structure and at least one first surface sealing portion 212 with a planar structure. The other side surface is provided with at least one second line sealing portion 213 with a raised structure and at least one second surface sealing portion 214 with a planar structure.

[0030] It is understandable that, such as Figure 1As shown, the first line sealing part 211, the first surface sealing part 212, the second line sealing part 213, and the second surface sealing part 214 are respectively arranged along the circumference of the integrated sealing body 200, forming a closed-loop structure.

[0031] In this embodiment, the first line sealing part 211 and the second line sealing part 213 respectively seal against the annular sealing groove 500 on the cathode plate 300 and the anode plate 400 to achieve line sealing, and the first surface sealing part 212 and the second surface sealing part 214 respectively seal against the surfaces of the cathode plate 300 and the anode plate 400 to achieve surface sealing.

[0032] This invention combines line sealing and surface sealing, which complement each other's advantages and disadvantages. It enhances the sealing force under high pressure while reducing clamping force, effectively preventing the risk of lateral displacement. Furthermore, it has high integration and increases assembly convenience, integrating the traditional two installation processes of outer frame and sealing ring into a single installation process of integrated sealing body 200.

[0033] Furthermore, in this embodiment, the first sealing part 212 and the second sealing part 214 are positioned correspondingly in the thickness direction. During assembly, the clamping force is applied between the first sealing part 212 and the second sealing part 214 in the thickness direction to improve the sealing performance.

[0034] Regarding the sealing of the membrane electrode assembly 100, such as Figures 1 to 3 As shown, the integrated sealing body 200 of this embodiment has an annular stepped groove 220 on the inner edge of one side surface. The differential pressure high-pressure PEM electrolytic cell of this embodiment operates under high cathode pressure and normal anode pressure. The stepped groove 220 faces the anode plate 400.

[0035] The membrane electrode assembly 100 includes a cathode diffusion layer 110, a proton exchange membrane 120, and an anode diffusion layer 130 sequentially bonded together. The proton exchange membrane 120 and the anode diffusion layer 130 extend to the stepped groove 220 around their periphery. The proton exchange membrane 120 is sealed and clamped between the anode diffusion layer 130 and the stepped groove 220 around its periphery. The cathode diffusion layer 110 is located in the inner ring of the integrated sealing body 200. It can be understood that one side of the proton exchange membrane 120 is sealed and abuts against the integrated sealing body 200, while the other side of the proton exchange membrane 120 is sealed and abuts against the anode diffusion layer 130. No outer frame is required. During assembly, the sealing performance can be improved by clamping force, and the membrane electrode assembly 100 can also be internally positioned for easy assembly.

[0036] In this embodiment, the first line sealing part 211 and the cathode diffusion layer 110 are located on the same side. The integrated sealing body 200 is provided with the first line sealing part 211 at the position opposite to the stepped groove 220. During assembly, the cathode plate 300 presses the stepped groove 220 through the first line sealing part 211 to make the sealing effect between the stepped groove 220 and the proton membrane 120 better.

[0037] Furthermore, in this embodiment, there are two first line sealing portions 211. One first line sealing portion 211 is located at the end of the sealing body 210 away from the stepped groove 220, and the other is located at the end of the sealing body 210 close to the stepped groove 220. The first surface sealing portion 212 is located between the two first line sealing portions 211, forming multiple seals on the cathode side. The line seals and surface seals are arranged in sequence to improve the sealing effect on the high-voltage side.

[0038] Furthermore, the first line sealing portion 211 and the second line sealing portion 213 located at the end of the sealing body 210 away from the stepped groove 220 are positioned correspondingly in the thickness direction. When the cathode plate 300 and the anode plate 400 are clamped together, the first line sealing portion 211 and the second line sealing portion 213 can be squeezed along the thickness direction to improve the sealing effect on both sides.

[0039] In this embodiment, the outer edge of the integrated sealing body 200 has the same outer dimension as the electrode plate, and it relies on external positioning during assembly.

[0040] In some embodiments, the proton exchange membrane 120 and the stepped groove 220 are connected by adhesive, which is one or more of hot melt adhesive, pressure-sensitive adhesive and UV adhesive, reducing assembly components and increasing the ease of electrolytic cell assembly.

[0041] Furthermore, thin borders 140 are provided along the edges of both sides of the proton membrane 120, such as... Figure 4 and Figure 5 As shown, assembly is performed using a dispensing and hot pressing method.

[0042] In some other embodiments, assembly can be performed using direct hot pressing, such as... Figure 1 and Figure 2 As shown.

[0043] In this embodiment, the first sealing part 212 is located at the edge of the cathode diffusion layer 110, and the distance between it and the cathode diffusion layer 110 is 0.5-1.5mm.

[0044] The second sealing part 214 is located at the edge of the anode diffusion layer 130, and the distance between it and the anode diffusion layer 130 is 0.3-1mm.

[0045] It is understood that in some embodiments, the two sides of the integrated sealing body 200, except for the positions of the first line sealing portion 211 and the second line sealing portion 213, are all occupied by the first surface sealing portion 212 and the second surface sealing portion 214.

[0046] In this embodiment, the integrated seal 200 is made of one or more of silicone rubber, EPDM rubber and fluororubber, and the hardness of the integrated seal 200 is greater than 70 Shore A to prevent excessive deformation and extrusion of the integrated seal 200 during clamping.

[0047] In some other embodiments, the integrated seal 200 is injection molded onto the cathode plate 300, increasing the ease of assembly of the electrolytic cell.

[0048] The present invention also proposes a PEM electrolyzer, including the integrated sealing structure described above. When assembling the electrolyzer, one bipolar plate is placed first, then the integrated sealing body 200 is placed, then the membrane electrode assembly 100 is placed, and then another bipolar plate is placed, and so on.

[0049] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0050] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. An integrated sealing structure for a PEM electrolytic cell, characterized in that, include: The electrode assembly includes two bipolar plates, each of which has at least one annular sealing groove on both sides. A membrane electrode assembly is sandwiched between the two bipolar plates; An integrated sealing body, having an annular structure, is an insulating component. It is sandwiched between two bipolar plates and sealed around the perimeter of the membrane electrode assembly. The cross-section of the integrated sealing body includes a flat sealing body. One side surface of the sealing body has at least one first line sealing portion with a raised structure and at least one first surface sealing portion with a planar structure. The other side surface has at least one second line sealing portion with a raised structure and at least one second surface sealing portion with a planar structure. The first and second surface sealing portions are positioned correspondingly in the thickness direction. The first and second line sealing portions respectively seal against the annular sealing grooves on the two bipolar plates, and the first and second surface sealing portions respectively seal against the surfaces of the two bipolar plates.

2. The integrated sealing structure according to claim 1, characterized in that: The integrated sealing body has an annular stepped groove on the inner edge of one side surface. The membrane electrode assembly includes a cathode diffusion layer, a proton membrane, and an anode diffusion layer that are sequentially bonded together. The proton membrane and the anode diffusion layer extend to the stepped groove around their periphery. The proton membrane is sealed and clamped between the anode diffusion layer and the stepped groove around its periphery. The cathode diffusion layer is located in the inner ring of the integrated sealing body.

3. The integrated sealing structure according to claim 2, characterized in that: The first line sealing part and the cathode diffusion layer are located on the same side, and the integrated sealing body has the first line sealing part located at the position opposite to the stepped groove.

4. The integrated sealing structure according to claim 3, characterized in that: The first line sealing part is provided in two parts, one of which is located at the end of the sealing body away from the stepped groove, and the other is located at the end of the sealing body close to the stepped groove. The first surface sealing part is located between the two first line sealing parts.

5. The integrated sealing structure according to claim 4, characterized in that: The first line sealing portion and the second line sealing portion are positioned correspondingly in the thickness direction at the end of the sealing body away from the stepped groove.

6. The integrated sealing structure according to claim 5, characterized in that: The proton exchange membrane is connected to the stepped groove by adhesive.

7. The integrated sealing structure according to claim 6, characterized in that: The proton exchange membrane has thin borders along the edges of both sides.

8. The integrated sealing structure according to claim 1, characterized in that: The integrated seal is made of one or more of silicone rubber, EPDM rubber and fluororubber, and the hardness of the integrated seal is greater than 7 Shore A.

9. The integrated sealing structure according to claim 1, characterized in that: The integrated seal is injection molded onto one of the bipolar plates.

10. A PEM electrolytic cell, characterized in that: Includes the integrated sealing structure as described in any one of claims 1 to 9.

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