High-pressure sealing structure suitable for AEM electrolytic bath

Abstract

The invention relates to the technical field of electrolytic cells, and mainly relates to a high-pressure sealing structure suitable for an AEM electrolytic cell, which comprises two end plates, and an anode insulation pad, an anode collector plate, an anode sealing pad, an anode diffusion layer, an MEA membrane electrode, a cathode diffusion layer, a cathode sealing pad, a cathode collector plate and a cathode insulation pad which are sequentially arranged in the two end plates, according to the AEM electrolytic bath sealing structure, the two end plates and the middle part are assembled to form a single electrolytic unit, the groove structures formed in the anode collector plate and the cathode collector plate are matched with the sealing rings and are in butt joint with the sealing gaskets, sealing between the groove structures and the sealing rings is achieved, and therefore the production cost is reduced, the size and weight of the electrolytic bath are reduced, and meanwhile the service life of the electrolytic bath is prolonged. The sealing structure is convenient to disassemble and maintain and can be repeatedly used.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cells, in particular to a high-pressure sealing structure suitable for AEM electrolytic cells. Background Art

[0002] AEM electrolyzers can operate at high electrical density (10000A / m²). Compared with traditional alkaline water electrolysis (ALK) hydrogen production electrolyzers, the hydrogen produced is more efficient and has a higher pressure. However, as the electrolysis pressure increases, the airtightness of the electrolyzer and the hydrogen corrosion resistance of the material also increase. This makes it easier for hydrogen and oxygen to mix when working under high pressure conditions, resulting in an increase in the hydrogen concentration in oxygen and a decrease in current efficiency. This places extremely high demands on the overall structure of the electrolyzer, especially the insulating sealing structure. Conventional sealing structures are large and inconvenient to disassemble. Therefore, it is urgent to develop a safe and reliable sealing structure. Summary of the invention

[0003] The purpose of the present invention is to provide a high-pressure sealing structure suitable for an AEM electrolytic cell to solve the problem that the traditional electrolytic unit sealing structure proposed in the above background technology is large in size and has a low sealing effect, resulting in mixing of hydrogen and oxygen, increasing the hydrogen concentration in oxygen and decreasing the current efficiency.

[0004] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a high-pressure sealing structure suitable for an AEM electrolytic cell, comprising two end plates, and an anode insulating pad, an anode current collecting plate, an anode sealing pad, an anode diffusion layer, an MEA membrane electrode, a cathode diffusion layer, a cathode sealing pad, a cathode current collecting plate and a cathode insulating pad arranged in sequence in the two end plates, and a single electrolysis unit is formed by assembling the two end plates and the intermediate component; a groove structure is provided on a side of the anode current collecting plate facing the anode sealing pad and a side of the cathode current collecting plate facing the cathode sealing pad, and the groove structure is arranged around a water inlet and outlet and a reaction zone; a convex structure is provided on a side of the anode sealing pad facing the MEA membrane electrode and a convex structure is provided on a side of the cathode sealing pad facing the MEA membrane electrode, and the convex structure is arranged around the water inlet and outlet and the reaction zone; a sealing ring matching the groove structure is fixed on a side of the anode sealing pad and a cathode sealing pad away from the MEA membrane electrode.

[0005] Preferably, the cross-sectional shape of the protrusion structure is a structure with the outer end spreading outward.

[0006] Preferably, a docking port is provided on the inner side of the groove structure, and an arc-shaped surface is provided on the outer side of the sealing ring corresponding to the docking port.

[0007] Preferably, a cavity is provided inside the sealing ring.

[0008] Preferably, the groove structure has a depth of 0.5-2 mm and a width of 2-8 mm, a thickness of the sealing ring of 0.6-2.5 mm and a width of the sealing ring of 3.5-8 mm.

[0009] Preferably, the anode sealing pad, cathode sealing pad, anode insulating pad and cathode insulating pad are made of at least one of polyphenylene sulfide, polysulfone, polytetrafluoroethylene and polyetheretherketone, and the thickness of the anode sealing pad and cathode sealing pad is 0.5-3 mm.

[0010] Preferably, the convex structure has a thickness of 0.1-1 mm and a width of 1-6 mm, and the positions of the convex structure and the groove structure correspond to each other.

[0011] Preferably, the sealing ring is at least one of modified ethylene propylene rubber, modified fluororubber, modified silicone rubber and fluorosilicone rubber.

[0012] Preferably, a butt-joint ring fixed to the sealing ring and the protruding structure is fixed inside the anode sealing pad and the cathode sealing pad, and a through hole is opened inside the butt-joint ring, and the through hole is connected with the cavity and the outer end of the protruding structure.

[0013] Compared with the prior art, the present invention has the following beneficial effects: The AEM electrolytic cell sealing structure designed in the present invention has a groove structure provided on the anode current collecting plate and the cathode current collecting plate, which cooperates with the sealing ring and docks with the sealing gasket to achieve sealing therebetween, thereby reducing the production cost and the volume and weight of the electrolytic cell. At the same time, the sealing structure of the present invention is convenient for disassembly and maintenance and can be reused. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the structure of the anode current collector and the anode sealing gasket of the present invention; Figure 3 It is a structural schematic diagram of the anode current collecting plate and the anode sealing gasket of the present invention from another angle; Figure 4 It is a cross-sectional schematic diagram of the positional relationship of the protrusion structure, the sealing ring and the groove structure of the present invention; Figure 5 It is a cross-sectional schematic diagram of the sealing ring and the groove structure of the present invention after being connected; Figure 6 It is a schematic diagram of the docking structure of the docking ring, the protruding structure and the sealing ring of the present invention; Figure 7 This is a schematic diagram comparing different sealing structures under conventional testing pressure of the present invention; Figure 8 It is a schematic diagram of the high pressure sealing test of the present invention.

[0015] In the figure: 1, end plate; 2, anode insulating pad; 3, anode current collecting plate; 4, anode sealing pad; 5, anode diffusion layer; 6, MEA membrane electrode; 7, cathode diffusion layer; 8, cathode sealing pad; 9, cathode current collecting plate; 10, cathode insulating pad; 11, groove structure; 12, protrusion structure; 13, sealing ring; 14, docking port; 15, cavity; 16, docking ring; 17, through hole. DETAILED DESCRIPTION

[0016] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions 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. 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.

[0017] Example 1: Please refer to Figure 1 - Figure 4 , a high-pressure sealing structure suitable for an AEM electrolyzer shown in the figure comprises two end plates 1, and an anode insulating pad 2, an anode current collecting plate 3, an anode sealing pad 4, an anode diffusion layer 5, an MEA membrane electrode 6, a cathode diffusion layer 7, a cathode sealing pad 8, a cathode current collecting plate 9 and a cathode insulating pad 10 arranged in sequence in the two end plates 1, and a single electrolysis unit is formed by assembling the two end plates 1 and the intermediate component; a groove structure 11 is provided on a side of the anode current collecting plate 3 facing the anode sealing pad 4 and a side of the cathode current collecting plate 9 facing the cathode sealing pad 8, and the groove structure 11 is arranged around the water inlet and outlet and the reaction zone, a side of the anode sealing pad 4 facing the MEA membrane electrode 6 and a side of the cathode sealing pad 8 facing the MEA membrane electrode 6 are provided with a convex structure 12, and the convex structure 12 is arranged around the water inlet and outlet, and a sealing ring 13 adapted to the groove structure 11 is fixed on a side of the anode sealing pad 4 and the cathode sealing pad 8 away from the MEA membrane electrode 6; In this solution, after the components between the two end plates 1 are assembled, the stacking pressure is used to compress the sealing ring 13 by 20%, so that the airtightness of the electrolytic cell can be above 4.6 MPa.

[0018] The sealing method of the AEM electrolytic cell in this scheme not only has a simple process, but also facilitates the assembly and disassembly of the electrolytic cell, while simplifying the internal structure of the electrolytic cell. It has the characteristics of low cost, simple assembly, high applicability, and easy industrial continuous production.

[0019] It should be noted that the designed groove structure 11 has a depth of 0.5-2 mm and a width of 2-8 mm, a thickness of the sealing ring 13 of 0.6-2.5 mm, and a width of the sealing ring 13 of 3.5-8 mm, so that the sealing ring 13 has a certain deformation range, ensuring that the cross-sectional compression rate is between 15% and 30%; It should also be noted that the thickness of the protrusion structure 12 is 0.1-1 mm and the width is 1-6 mm. The positions of the protrusion structure 12 and the groove structure 11 correspond to each other. The corresponding design makes the sealing structure designed in this scheme bear uniform force.

[0020] At the same time, in the present embodiment, the material of the anode sealing pad 4, the cathode sealing pad 8, the anode insulating pad 2 and the cathode insulating pad 10 is at least one of polyphenylene sulfide, polysulfone, polytetrafluoroethylene, and polyetheretherketone, the thickness of the anode sealing pad 4 and the cathode sealing pad 8 is 0.5-3mm, and the sealing ring 13 is at least one of modified ethylene propylene rubber and fluorosilicone rubber.

[0021] For further information, see Figure 4 and Figure 5 The cross-sectional shape of the protrusion structure 12 is a structure with the outer end expanding outward, so that when it is squeezed and contacted, it will expand outward, thereby increasing the contact area and achieving a better sealing effect; Also, see Figure 4 and Figure 5 A docking port 14 is formed on the inner side of the groove structure 11 , an arc-shaped surface is formed on the outer side of the sealing ring 13 corresponding to the docking port 14 , and a cavity 15 is formed inside the sealing ring 13 .

[0022] It should also be noted that the design of the docking port 14 enables the sealing ring 13 to increase the contact area and improve the sealing effect when it enters the groove structure 11 and is squeezed. At the same time, the design of the cavity inside the sealing ring 13 makes it easier to deform, and the arc surface on the outside of the sealing ring 13 is easier to fit with the docking port 14.

[0023] In this proposal, see Figure 7 , the plate sealing ring 13 is combined with the sealing gasket protrusion structure 12, and after a 24h, 3.2 MPa airtight pressure test, the pressure drop rate is less than 0.1%; See also Figure 8 , further increasing the stacking pressure, so that the deformation of the sealing ring 13 and the protruding structure 12 is increased, compared with the conventional plane type, after 24h, 6 MPa airtight pressure test, the pressure reduction rate is less than 0.1%.

[0024] Example 2: Please refer to Figure 6This embodiment further explains the first embodiment, and the difference lies in that the shapes of the sealing ring 13 and the protruding structure 12 are optimized, so that the assembly between the two and other components is more stable.

[0025] Specifically, a butt-joint ring 16 fixed to the sealing ring 13 and the protruding structure 12 is fixed inside the anode sealing gasket 4 and the cathode sealing gasket 8, and a through hole 17 is opened inside the butt-joint ring 16, and the through hole 17 is connected to the cavity 15 and the outer end of the protruding structure 12; In this solution, by designing the through hole 17, when the protrusion structure 12 is squeezed, the gas remaining at the upper end can be smoothly discharged into the cavity 15 through the through hole 17. At the same time, after the sealing ring 13 is docked with the groove structure 11, it is squeezed and deformed, so that it fits with the docking port 14 in the groove structure 11. The gas stored in the cavity 15 can increase the outward expansion force of the sealing ring 13 itself, so that the sealing ring 13 and the groove structure 11 fit more stably and tightly.

[0026] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0027] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-pressure sealing structure suitable for an AEM electrolyzer, characterized in that: include: Two end plates (1), and an anode insulating pad (2), an anode current collecting plate (3), an anode sealing pad (4), an anode diffusion layer (5), an MEA membrane electrode (6), a cathode diffusion layer (7), a cathode sealing pad (8), a cathode current collecting plate (9) and a cathode insulating pad (10) arranged in sequence in the two end plates (1), wherein a single electrolysis unit is formed by assembling the two end plates (1) and an intermediate component; A groove structure (11) is provided on one side of the anode current collector plate (3) facing the anode sealing gasket (4) and a groove structure (11) is provided on one side of the cathode current collector plate (9) facing the cathode sealing gasket (8). The groove structure (11) is arranged around the water inlet and outlet and the reaction zone. A protrusion structure (12) is provided on one side of the anode sealing gasket (4) facing the MEA membrane electrode (6) and a protrusion structure (12) is provided on one side of the cathode sealing gasket (8) facing the MEA membrane electrode (6). The protrusion structure (12) is arranged around the water inlet and outlet. A sealing ring (13) matching the groove structure (11) is fixed on one side of the anode sealing gasket (4) and the cathode sealing gasket (8) away from the MEA membrane electrode (6).

2. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 1, characterized in that: The cross-sectional shape of the protruding structure (12) is a structure with the outer end spreading outwards.

3. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 1, characterized in that: A docking port (14) is provided on the inner side of the groove structure (11), and an arc-shaped surface is provided on the outer side of the sealing ring (13) corresponding to the docking port (14).

4. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 3, characterized in that: A cavity (15) is provided inside the sealing ring (13).

5. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 3, characterized in that: The groove structure (11) has a depth of 0.5-2 mm and a width of 2-8 mm; the sealing ring (13) has a thickness of 0.6-2.5 mm and a width of 3.5-8 mm.

6. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 1, characterized in that: The material of the anode sealing pad (4), cathode sealing pad (8), anode insulating pad (2) and cathode insulating pad (10) is at least one of polyphenylene sulfide, polysulfone, polytetrafluoroethylene and polyetheretherketone, and the thickness of the anode sealing pad (4) and cathode sealing pad (8) is 0.5-3 mm.

7. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 2, characterized in that: The convex structure (12) has a thickness of 0.1-1 mm and a width of 1-6 mm, and the convex structure (12) and the concave structure (11) correspond to each other in position.

8. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 3, characterized in that: The sealing ring (13) is at least one of modified ethylene-propylene rubber, modified fluororubber, modified silicone rubber, and fluorosilicone rubber.

9. A high-pressure sealing structure suitable for an AEM electrolyzer according to claim 4, characterized in that: A docking ring (16) fixed to the sealing ring (13) and the protruding structure (12) is fixed inside the anode sealing gasket (4) and the cathode sealing gasket (8), and a through hole (17) is provided inside the docking ring (16), and the through hole (17) is connected to the cavity (15) and the outer end of the protruding structure (12).

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