Membrane electrode edge sealing structure and proton exchange membrane electrolytic cell

Abstract

The application relates to the technical field of proton exchange membrane electrolyzers, in particular to a membrane electrode edge sealing structure and a proton exchange membrane electrolyzer, which comprises a first frame, a second frame arranged below the first frame, and a third frame arranged below the second frame, wherein the inner edge of the second frame exceeds the inner edges of the first frame and the third frame in the radial direction; and the frames are connected through an adhesive layer. By adding a layer of edge sealing structure in the middle of the existing double-layer edge sealing structure and cooperating with the corresponding adhesive layer, the height of the membrane electrode edge sealing structure after hot pressing is similar to that of the membrane electrode, the T-shaped height difference is eliminated as much as possible, the uniform stress capacity of the membrane electrode frame is improved, the pressure resistance of the electrolyzer is enhanced, the interface sealing effect is optimized, the hydrogen-oxygen leakage rate is significantly reduced, and a more reliable solution is provided for the manufacturing of high-purity and long-service-life proton exchange membrane electrolyzers.

Description

Technical Field

[0001] This application relates to the field of proton exchange membrane electrolyzer technology, and more specifically to a membrane electrode sealing structure and a proton exchange membrane electrolyzer. Background Technology

[0002] The proton exchange membrane (PEM) electrolyzer is one of the core pieces of equipment for producing green hydrogen, and the sealing reliability of its membrane electrode assembly directly affects the electrolysis efficiency and service life of the proton exchange membrane electrolyzer.

[0003] Reference Appendix Figure 1 As shown, the current industry-used membrane electrode sealing structure is a double-layer structure. In practical applications, the applicant has discovered significant technical defects in this structure. (See attached reference.) Figure 2 and 3 As shown, the defect of this double-layer sealing structure is that the total thickness of the double-layer frame used deviates significantly from the thickness of the membrane electrode. After hot pressing and assembly, a T-shaped interface structure is formed at the junction of the sealing structure and the membrane electrode. Stress concentration occurs at the junction, which will reduce the sealing strength over long-term use, leading to damage points in the sealing structure. This becomes the main channel for hydrogen-oxygen leakage, affecting the reliability of the proton exchange membrane (PEM) electrolyzer and shortening its service life.

[0004] To address the above issues, the industry has generally tried to compensate for the height difference by optimizing hot pressing parameters or increasing the thickness of the adhesive layer, but it is difficult to balance sealing reliability and thickness consistency. Summary of the Invention

[0005] This application discloses a novel membrane electrode sealing structure and a proton exchange membrane electrolyzer. By adding a frame layer to the double-layer sealing structure, the thickness difference between the membrane electrode sealing structure and the proton exchange membrane after hot pressing is reduced, improving the consistency between the sealing structure and the proton exchange membrane, thereby minimizing the T-shaped height difference. This design not only improves the uniform stress distribution of the frame and enhances the pressure resistance of the electrolyzer, but also significantly reduces hydrogen-oxygen leakage by optimizing the interface sealing effect, providing a more reliable solution for the manufacture of high-purity, long-life proton exchange membrane (PEM) electrolyzers.

[0006] In a first aspect, a membrane electrode sealing structure includes: First border; The second border is superimposed below the first border; The third border is superimposed below the second border; The inner edge of the second frame extends radially beyond the inner edges of the first and third frames; the frames are connected by an adhesive layer.

[0007] Preferably, the thickness of the adhesive layer is greater than the thickness of any of the frame edges.

[0008] Preferably, the ratio of the thickness of any of the frame edges to the thickness of the adhesive layer is 50% - 78%.

[0009] Preferably, the adhesive layer is applied to both the upper and lower surfaces of the second frame.

[0010] Preferably, the total thickness of the second frame and the two adhesive layers is not less than the thickness of the membrane electrode.

[0011] Preferably, the lower surface of the first frame is also covered with the adhesive layer.

[0012] Preferably, the upper surface of the third frame is also covered with the adhesive layer.

[0013] Preferably, the first frame and the third frame sandwich the periphery of the membrane electrode.

[0014] Preferably, the periphery of the membrane electrode is tangent to or has a gap with the inner edge of the second frame.

[0015] In a second aspect, a proton exchange membrane electrolyzer uses the membrane electrode sealing structure described in any one of the above claims.

[0016] This utility model can achieve the following beneficial effects: 1. By adding a sealing layer in the middle of the existing double-layer sealing structure and using a corresponding adhesive layer, the height of the membrane electrode sealing structure after hot pressing can be similar to that of the membrane electrode, thereby eliminating the T-shaped height difference as much as possible, improving the uniform stress capacity of the membrane electrode frame, enhancing the pressure resistance of the electrolyzer, and significantly reducing the hydrogen-oxygen leakage rate by optimizing the sealing effect, providing a more reliable solution for the manufacture of high-purity, long-life PEM electrolyzers; 2. Precisely set the thickness ratio of the adhesive layer to the edge sealing structure to avoid displacement of the edge sealing structure after hot pressing, achieve zero displacement and precise edge sealing, and further improve the sealing effect. Attached Figure Description

[0017] The accompanying drawings, which are incorporated herein and form part of this specification, illustrate one or more embodiments of the present application and, together with the description, serve to explain the principles of the present application and to enable those skilled in the art to make and use the present application.

[0018] Figure 1 This is an exploded view of the membrane electrode sealing structure with a double-layer frame used in the prior art.

[0019] Figure 2 This is a schematic cross-sectional view of the membrane electrode sealing structure with a double-layer frame used in the prior art before hot pressing.

[0020] Figure 3This is a schematic cross-sectional view of the membrane electrode sealing structure with a double-layer frame used in the prior art after hot pressing.

[0021] Figure 4 This is an exploded view of the membrane electrode sealing structure and membrane electrode of this application.

[0022] Figure 5 This is a schematic cross-sectional view of one of the membrane electrode sealing structures of this application before hot pressing.

[0023] Figure 6 This is a schematic cross-sectional view of another membrane electrode sealing structure of this application before hot pressing.

[0024] Figure 7 This is a schematic cross-sectional view of another membrane electrode sealing structure after hot pressing according to this application.

[0025] Explanation of reference numerals in the attached figures: 1. First border; 2. Second border; 3. Third border; 4. Adhesive layer; 5. Window; 6. Membrane electrode; 61. Cathode catalyst layer; 62. Proton exchange membrane; 63. Anode catalyst layer. Detailed Implementation

[0026] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the examples set forth herein; rather, they are provided to make this application more complete and comprehensive, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a full understanding of embodiments of this application. Example 1

[0027] Reference Appendix Figure 4-5 As shown, a membrane electrode sealing structure includes: First border 1; The second border 2 is superimposed below the first border 1; The third border 3 is superimposed below the second border 2; The inner edge of the second frame 2 extends radially beyond the inner edges of the first frame 1 and the third frame 3; the frames are connected by an adhesive layer 4.

[0028] Specifically, the first border 1, the second border 2, and the third border 3 are all square-shaped with a window 5 in the middle. The window 5 is used to expose the reaction area of ​​the membrane electrode 6 after encapsulation.

[0029] The inner edge of the second frame 2 extends beyond the inner edges of the first frame 1 and the third frame 3 in the radial direction. The radial direction refers to the direction from the center point of the second frame 2 outward and perpendicular to the four sides. It can be understood that the window 5 area of ​​the second frame 2 is larger than the window 5 area of ​​the first frame 1 and the second frame 2. When the first frame 1, the second frame 2, and the third frame 3 are stacked in sequence, the inner edge of the second frame 2 forms a groove relative to the inner edges of the first frame 1 and the third frame 3. This groove is used to place the membrane electrode 6.

[0030] Preferably, the thickness of the adhesive layer 4 is greater than the thickness of any of the frame edges. In practice, when this solution is adopted, the thick adhesive layer 4 undergoes compressible deformation under hot pressing and high pressure differential conditions, effectively absorbing the thickness tolerance between the sealing structure and the membrane electrode 6, and avoiding rigid extrusion that could cause the membrane electrode 6 to crack.

[0031] Preferably, the ratio of the thickness of any frame to the thickness of the adhesive layer 4 is 50%-78%. In practice, the applicant has found that when the ratio of the frame thickness to the adhesive layer 4 thickness is 50%-78%, the advantages of this solution can be maximized, balancing the thickness tolerance between the sealing structure and the membrane electrode 6. Furthermore, at this ratio, potential displacement between frames can be effectively avoided. When the ratio of the thickness of any frame to the thickness of the adhesive layer 4 is 78%, the adhesive layer 4 is still more than 22% thicker than the frame, preserving the elastic buffering and self-sealing reinforcement effects while ensuring that the multi-layer frame will not shift after hot pressing. If the ratio of the thickness of any frame to the thickness of the adhesive layer 4 exceeds 78%, the adhesive layer 4 is too thick, and there may be a risk of frame displacement after hot pressing. When the ratio of the thickness of any frame to the thickness of adhesive layer 4 is 50%, the thickness of adhesive layer 4 does not exceed twice the thickness of the frame. During hot pressing, while retaining the elastic buffering and self-sealing reinforcement effects, it also ensures that the multi-layer frame will not shift after hot pressing, and adhesive layer 4 will not overflow excessively. As a preferred embodiment, the ratio of the thickness of any frame to the thickness of adhesive layer 4 can be 60% - 70%. As the optimal embodiment, the ratio of the thickness of any frame to the thickness of adhesive layer 4 can be 64%.

[0032] As a preferred option, please refer to the appendix. Figure 5 In the structure shown, the upper and lower surfaces of the second frame 2 are both covered with the adhesive layer 4. After hot pressing, the first frame 1, the second frame 2, and the third frame 3 are connected by the adhesive layer 4, relative to the attached... Figure 2 The double-layer structure shown in this application and the triple-layer structure can reduce the thickness difference between the sealing structure and the membrane electrode 6, thereby reducing the stress at the interface and preventing damage to the sealing structure during use.

[0033] Preferably, the total thickness of the second frame 2 and the two adhesive layers 4 is not less than the thickness of the membrane electrode 6. In practice, the applicant has found that under this limitation, better results can be achieved, and the thickness difference between the sealing structure and the membrane electrode 6 can be reduced.

[0034] As a preferred option, please refer to the appendix. Figure 6-7 As shown, the lower surface of the first frame 1 is also covered with the adhesive layer 4. To further eliminate the thickness difference between the sealing structure and the membrane electrode 6, improve the bonding strength between the first frame 1 and the second frame 2, and enhance the elastic buffering capacity, the adhesive layer 4 can also be provided on the lower surface of the first frame 1.

[0035] As a preferred option, please refer to the appendix. Figure 6-7 As shown, the upper surface of the third frame 3 is also covered with the adhesive layer 4. To further eliminate the thickness difference between the sealing structure and the membrane electrode 6, improve the bonding strength between the second frame 2 and the third frame 3, and enhance the elastic buffering capacity, the adhesive layer 4 can also be provided on the upper surface of the third frame 3.

[0036] As a preferred option, please refer to the appendix. Figure 6-7 As shown, the first frame 1 and the third frame 3 clamp the periphery of the membrane electrode 6. After hot pressing, the first frame 1 and the third frame 3 enclose the membrane electrode 6 to form a complete membrane electrode 6 assembly.

[0037] As a preferred option, please refer to the appendix. Figure 6-7 As shown, the periphery of the membrane electrode 6 is tangent to or has a gap with the inner edge of the second frame 2. In practice, the applicant has found that under this limitation, space can be provided for the radial thermal expansion of the membrane electrode 6, reducing the risk of wrinkling of the membrane electrode 6. At the same time, the adhesive layer 4 will generate a certain fluidity during hot pressing, filling the gap between the periphery of the membrane electrode 6 and the second frame 2, realizing secondary gap filling and sealing, further avoiding the formation of air leakage channels and improving sealing performance. Example 2

[0038] A proton exchange membrane electrolyzer uses the membrane electrode sealing structure described in any of the above embodiments. The proton exchange membrane electrolyzer using the membrane electrode sealing structure of Embodiment 1 improves the uniform stress distribution of the sealing frame, enhances the pressure resistance of the proton exchange membrane electrolyzer, and significantly reduces hydrogen-oxygen leakage rate by optimizing the interface sealing effect, thereby improving gas purity and equipment lifespan.

[0039] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be limited to the scope of protection of the claims.

Claims

1. A membrane electrode sealing structure, characterized in that, include: First border; The second border is superimposed below the first border; The third border is superimposed below the second border; The inner edge of the second frame extends beyond the inner edges of the first and third frames in the radial direction. Each frame is connected by an adhesive layer, and the upper and lower surfaces of the second frame are covered with the adhesive layer, the thickness of which is greater than the thickness of any frame.

2. The membrane electrode sealing structure according to claim 1, characterized in that, The ratio of the thickness of any of the frame edges to the thickness of the adhesive layer is 50% - 78%.

3. The membrane electrode sealing structure according to claim 1, characterized in that, The total thickness of the second frame and the two adhesive layers is not less than the thickness of the membrane electrode.

4. The membrane electrode sealing structure according to claim 1, characterized in that, The adhesive layer is also covered on the lower surface of the first frame.

5. The membrane electrode sealing structure according to claim 1, characterized in that, The upper surface of the third frame is also covered with the adhesive layer.

6. A membrane electrode sealing structure according to any one of claims 1-5, characterized in that, The first and third frame frames hold the periphery of the membrane electrode.

7. The membrane electrode sealing structure according to claim 6, characterized in that, The periphery of the membrane electrode is tangent to or has a gap with the inner edge of the second frame.

8. A proton exchange membrane electrolyzer, characterized in that, Use the membrane electrode sealing structure according to any one of claims 1-7.

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