Sealing assembly for AEM electrolytic cell, AEM electrolytic chamber unit and AEM electrolytic cell system

Abstract

The invention discloses a sealing assembly for an AEM electrolytic cell, an AEM electrolytic chamber unit and an AEM electrolytic cell system, and belongs to the technical field of water electrolysis hydrogen production. The sealing assembly comprises a first annular sealing piece and a second annular sealing piece, wherein the first annular sealing piece is provided with a first through hole; a plurality of first concave parts and a plurality of first convex parts are arranged on the ring surface; the second annular sealing piece is provided with a second through hole; a plurality of second concave parts and a plurality of second convex parts are arranged on the ring surface; the first concave part is used for being meshed with the second convex part, and the first convex part is used for being meshed with the second concave part, so that the first annular sealing piece and the second annular sealing piece form an interlocking structure. According to the sealing assembly, the sealing effect and stability of the AEM electrode membrane assembly are remarkably enhanced, and leakage of electrolyte or generated gas in the AEM membrane assembly is avoided. Meanwhile, the meshing structure can allow dynamic deformation to a certain degree, and the AEM electrolytic cell can operate and work for a long time under high-temperature alkalinity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, in particular to a sealing assembly for AEM electrolytic cell, AEM electrolytic chamber unit and AEM electrolytic cell system. BACKGROUND

[0002] Anion exchange membrane water electrolysis (AEMWE) technology is a new type of hydrogen production by water electrolysis technology based on anion exchange membrane (AEM) as an ion-conducting separator. By integrating the low-cost advantage of alkaline water electrolysis (ALKWE) and the high current density and fast dynamic response characteristics of proton exchange membrane water electrolysis (PEMWE), it shows significant potential in improving hydrogen production efficiency and reducing system cost.

[0003] An AEM electrolytic cell is mainly composed of an AEM membrane electrode and a polar plate. Hydrogen is generated at the cathode and oxygen is generated at the anode during the reaction of the membrane electrode. The reaction water passes through the anion membrane to the cathode. A sealing element is needed between the membrane electrode and the polar plate to prevent hydrogen from escaping and electrolyte from leaking.

[0004] The existing technology mainly uses the sealing frame in the fuel cell to reinforce the glue sealing or uses the sealing gasket in the alkaline electrolytic cell to seal. However, the sealing effect of the sealing assembly in the related technology cannot meet the sealing reliability requirements of the AEM electrolytic cell. For example, 1) ordinary sealing frame will have sealing defects in alkaline solution, which will cause electrolyte leakage, reduce the membrane ion conductivity (OH-transport is blocked), and accelerate the corrosion of the bipolar plate and the diffusion layer, thereby affecting the performance of the entire electrolytic cell; 2) due to the long-term swelling and chemical degradation of the anion exchange membrane in a high-temperature and alkaline environment, the membrane thickness changes, the static compression amount of the sealing interface is destroyed, and micro-leakage occurs, resulting in poor sealing of the electrolytic cell. SUMMARY

[0005] The main purpose of the present application is to provide a sealing assembly for AEM electrolytic cell, AEM electrolytic chamber unit and AEM electrolytic cell system to solve the problem of poor sealing effect of the sealing element of the AEM electrolytic cell in the prior art, which leads to electrolyte leakage.

[0006] In order to achieve the above-mentioned purpose, according to one aspect of the present application, a sealing assembly for AEM electrolytic cell is provided, comprising:

[0007] The first annular sealing element has a first through hole; a plurality of first recesses and a plurality of first protrusions are arranged on the annular surface of the first annular sealing element;

[0008] The second annular sealing element has a second through hole; a plurality of second recesses and a plurality of second protrusions are arranged on the annular surface of the second annular sealing element;

[0009] The first recesses are configured to engage with the second protrusions, and the first protrusions are configured to engage with the second recesses, so that the first ring-shaped seal and the second ring-shaped seal form an interlocking structure by engagement.

[0010] Further, a plurality of first recesses and a plurality of first protrusions are arranged on one of the annular surfaces of the first ring-shaped seal.

[0011] Further, a plurality of second recesses and a plurality of second protrusions are arranged on one of the annular surfaces of the second ring-shaped seal.

[0012] Further, the first ring-shaped seal and the second ring-shaped seal each have a square outer contour shape.

[0013] Further, the first through hole and the second through hole each have a square contour shape.

[0014] Further, the first ring-shaped seal is made of polytetrafluoroethylene.

[0015] Further, the second ring-shaped seal is made of thermoplastic polyester elastomer.

[0016] Further, the first ring-shaped seal has a thickness of 0.45-0.50 mm.

[0017] Further, the second ring-shaped seal has a thickness of 0.30-0.40 mm.

[0018] Further, the first recesses are arranged on the surface of the first ring-shaped seal at a density of 6-8 per cm 3 .

[0019] Further, the first protrusions are arranged on the surface of the first ring-shaped seal at a density of 7-9 per cm 3 .

[0020] Further, the first recesses and the first protrusions are arranged alternately on the surface of the first ring-shaped seal.

[0021] Further, the first recesses and the first protrusions are arranged in a matrix on the surface of the first ring-shaped seal.

[0022] Further, the second recesses are arranged on the surface of the second ring-shaped seal at a density of 7-9 per cm 3 .

[0023] Further, the second protrusions are arranged on the surface of the second ring-shaped seal at a density of 6-8 per cm 3 .

[0024] Further, the second recesses and the second protrusions are arranged alternately on the surface of the second ring-shaped seal.

[0025] Further, the second concave parts and the second convex parts are arranged in a matrix on the surface of the second annular seal.

[0026] Further, the cavities in the first concave parts are semispherical, spherical cap or quadrangular platform, and the second convex parts are semispherical, spherical cap or regular quadrangular platform in turn.

[0027] Further, the first convex parts are semispherical, spherical cap or regular quadrangular platform, and the cavities in the second concave parts are semispherical, spherical cap or regular quadrangular platform in turn.

[0028] Further, the depth of the first concave parts and the height of the second convex parts are the same and are 0.04-0.06mm.

[0029] Further, the height of the first convex parts and the depth of the second concave parts are the same and are 0.05-0.07mm.

[0030] According to a second aspect of the present application, an AEM electrolysis chamber unit is provided, which comprises, from the cathode side to the anode side, a cathode end plate, a cathode electrode plate, a first annular seal, an AEM electrode membrane assembly, a second annular seal, an anode electrode plate and an anode end plate in turn; wherein the AEM electrode membrane assembly comprises a cathode gas diffusion layer, a cathode catalyst layer, an AEM electrode membrane, an anode catalyst layer and an anode gas diffusion layer which are stacked in turn; wherein the first annular seal and the second annular seal are the first annular seal and the second annular seal of the sealing assembly for the AEM electrolysis tank described above; the AEM electrode membrane is arranged in the region of the first through hole of the first annular seal and / or the second through hole of the second annular seal, and the non-catalytic layer edge film edge of the AEM electrode membrane is clamped in the interlocking structure formed by the occlusion of the first annular seal and the second annular seal.

[0031] Further, the cathode gas diffusion layer and the cathode electrode plate are pressed together.

[0032] Further, the anode gas diffusion layer and the anode electrode plate are pressed together.

[0033] Further, the AEM electrode membrane assembly is provided with an electrolyte inlet and an electrolyte outlet.

[0034] Further, the AEM electrode membrane assembly is a CCS type membrane electrode assembly or a CCM type membrane electrode assembly.

[0035] According to a third aspect of the present application, a method for assembling the AEM electrolysis chamber unit described above is provided, which comprises the following steps:

[0036] Step S1: stacking the cathode end plate, the cathode electrode plate, the first annular seal, the AEM electrode membrane assembly, the second annular seal, the anode electrode plate and the anode end plate in turn to form an initial electrolysis chamber;

[0037] The AEM electrode film assembly comprises, in sequence, a cathode gas diffusion layer, a cathode catalyst layer, an AEM electrode film, an anode catalyst layer, and an anode gas diffusion layer; and the non-catalytic layer edge film edge of the AEM electrode film is clamped between the first annular sealing member and the second annular sealing member.

[0038] Step S2: Apply relative extrusion force to the cathode end plate and the anode end plate of the initial electrolysis chamber to fasten and seal, to obtain a sealed AEM electrolysis chamber unit; wherein the first annular sealing member and the second annular sealing member are interlocked under the action of the extrusion force to fix the AEM electrode film between the two annular sealing members.

[0039] Further, in step S1, before the first annular sealing member and the second annular sealing member are engaged, the thickness of the first annular sealing member is greater than the total thickness of the cathode gas diffusion layer and the cathode catalyst layer.

[0040] Further, the thickness of the first annular sealing member is 1.125-1.25 times the total thickness of the cathode gas diffusion layer and the cathode catalyst layer.

[0041] Further, in step S1, before the first annular sealing member and the second annular sealing member are engaged, the thickness of the second annular sealing member is greater than the total thickness of the anode gas diffusion layer and the anode catalyst layer.

[0042] Further, the thickness of the second annular sealing member is 1.5-2.0 times the total thickness of the anode gas diffusion layer and the anode catalyst layer.

[0043] Further, in step S1, before the first annular sealing member and the second annular sealing member are engaged, the width of the first gap between the cathode gas diffusion layer and the cathode end plate is less than the width of the second gap between the anode gas diffusion layer and the anode end plate.

[0044] Further, the thickness of the first annular sealing member is 0.45-0.50 mm.

[0045] Further, the thickness of the cathode gas diffusion layer is 0.38-0.42 mm.

[0046] Further, the thickness of the AEM electrode film is 0.04-0.07 mm.

[0047] Further, the thickness of the second annular sealing member is 0.30-0.40 mm.

[0048] Further, the thickness of the anode gas diffusion layer is 0.20-0.25 mm.

[0049] According to a fourth aspect of the present application, there is provided an AEM electrolytic cell system comprising a plurality of sets of AEM electrolytic cell units connected in series; the AEM electrolytic cell unit is the AEM electrolytic cell unit as described above, or the AEM electrolytic cell unit obtained by the assembly method as described above.

[0050] Compared with the prior art, the present application has the following beneficial effects:

[0051] The split type seal assembly capable of forming interlocking structure by occlusion designed in the present application can significantly enhance the sealing effect and stability of the AEM electrode film assembly by tightly fixing the AEM electrode film assembly in the interlocking structure formed by occlusion of the two seal members, thereby avoiding leakage of electrolyte or generated gas in the AEM electrolytic cell; at the same time, the occlusion structure can allow a certain degree of dynamic deformation, which is beneficial to long-term operation of the AEM electrolytic cell under high temperature and alkaline conditions. BRIEF DESCRIPTION OF DRAWINGS

[0052] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application, serve to explain the present application, and do not constitute improper limitations on the present application. In the drawings:

[0053] Figure 1 A plan view of the seal assembly provided for Embodiment 1 of the present application;

[0054] Figure 2 A side view of the seal assembly provided for Embodiment 1 of the present application before occlusion;

[0055] Figure 3 A partial side view of the seal assembly provided for Embodiment 1 of the present application, in which the concave part and the convex part are circular arc profile;

[0056] Figure 4 A partial side view of the seal assembly provided for Embodiment 2 of the present application, in which the concave part and the convex part are trapezoidal profile;

[0057] Figure 5 An exploded view of the components of the AEM electrolytic cell unit provided for Embodiment 5 of the present application;

[0058] Figure 6 A side view of the seal assembly of the AEM electrolytic cell unit provided for Embodiment 5 of the present application before occlusion;

[0059] Figure 7 A side view of the seal assembly of the AEM electrolytic cell unit provided for Embodiment 5 of the present application after occlusion.

[0060] Reference signs:

[0061] 1, cathode end plate; 2, cathode electrode plate;

[0062] 3, seal assembly;

[0063] 31, first annular sealing member; 311, first through hole; 312, first recess; 313, first protrusion;

[0064] 32, second annular sealing member; 321, second through hole; 322, second recess; 323, second protrusion;

[0065] 4, AEM electrode membrane assembly; 41, cathode gas diffusion layer; 42, cathode catalyst layer; 43, AEM electrode membrane; 44, anode catalyst layer; 45, anode gas diffusion layer; 46, electrolyte inlet; 47, electrolyte outlet;

[0066] 5, anode plate; 6, anode end plate; 7, first gap; 8, second gap. DETAILED DESCRIPTION

[0067] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. The present application will be described in detail below with reference to the embodiments.

[0068] The common sealing frame used by the AEM electrolysis system as described in the background art will have sealing defects in the alkali solution, which will cause electrolyte leakage, reduce the membrane ion conductivity (OH-transport is blocked), and accelerate the corrosion of the bipolar plate and the diffusion layer, thereby affecting the performance of the entire electrolytic cell; and the anion exchange membrane will appear long-term swelling and chemical degradation in a high-temperature and alkaline environment, resulting in changes in the thickness of the membrane, destroying the static compression amount of the sealing interface, and then appearing micro-leakage, resulting in poor sealing performance of the electrolytic cell.

[0069] According to a first aspect of the present application, a sealing assembly for an AEM electrolytic cell is provided, as shown in Figure 1 and Figure 2 The sealing assembly 3 includes: a first annular sealing member 31 having a first through hole 311; a plurality of first recesses 312 and a plurality of first protrusions 313 are arranged on the annular surface of the first annular sealing member 31; a second annular sealing member 32 having a second through hole 321; a plurality of second recesses 322 and a plurality of second protrusions 323 are arranged on the annular surface of the second annular sealing member; wherein the first recess 312 of the first annular sealing member 31 is used to engage with the second protrusion 323 of the second annular sealing member 32; the first protrusion 313 of the first annular sealing member 31 is used to engage with the second recess 322 of the second annular sealing member 32, so that the first annular sealing member 31 and the second annular sealing member 32 form an interlocking structure by engagement.

[0070] In the split interlocking structure designed by the present application, the groove shape of the concave part and the outer shape of the convex part are the same, so that the convex part is adaptively embedded in the concave part, and the outer surface of the convex part tightly fits the inner surface of the concave part, so that the concave part and the convex part are tightly interlocked. By tightly fixing the AEM electrode membrane assembly in the interlocking structure formed by the interlocking of the two sealing elements, the sealing effect and stability of the AEM electrode membrane assembly are significantly enhanced, and the leakage of electrolyte or generated gas in the AEM electrolysis cell is avoided. At the same time, this interlocking structure can allow a certain degree of dynamic deformation, which is beneficial to the long-term operation of the AEM electrolysis cell under various temperature and pressure conditions; for example, in the process of electrolyzing water to produce hydrogen, temperature changes may cause materials to expand or shrink, and the interlocking structure can dynamically adjust the sealing gap to maintain a good sealing state; and the split interlocking structure can use the most suitable material for each part, which is more suitable for the working environment on the different electrode sides; for example, the material of the first annular sealing element on the cathode side can be selected from alkali-resistant, high-temperature-resistant, and high-pressure-resistant materials suitable for the cathode side operating environment, and the material of the second annular sealing element on the anode side can be selected from elastic materials with a larger deformation amount suitable for the anode side operating environment.

[0071] As mentioned above, the cathode operating environment of the electrolysis cell is highly corrosive, high temperature and high pressure; in order to adapt to the cathode operating environment, in some embodiments, the material of the first annular sealing element 31 is polytetrafluoroethylene, further high-density polytetrafluoroethylene material. This material has strong corrosion resistance, small deformation, high pressure resistance and other advantages, and is suitable for the hydrogen production operating environment of the cathode. At the same time, a large amount of oxygen is generated in the anode operation of the electrolysis cell, and a large deformation amount is required; in order to adapt to the anode operating environment, in some embodiments, the material of the second annular sealing element 32 is thermoplastic polyester elastomer material (TPEE). This material has strong deformation ability and can meet the dynamic deformation compensation that occurs during long-term operation.

[0072] In order to adapt to the assembly of the electrolytic cell and improve the sealing effect of the AEM electrode membrane assembly, in some embodiments, a plurality of first recesses 312 and a plurality of first protrusions 313 are arranged on one of the annular surfaces of the first annular sealing member 31; a plurality of second recesses 322 and a plurality of second protrusions 323 are arranged on one of the annular surfaces of the second annular sealing member; recesses and protrusions can also be arranged on both opposite surfaces of the sealing member, but in order to further improve the sealing effect, it is preferred that recesses and protrusions are arranged only on one of the annular surfaces of the opposite surfaces, forming a continuous wavy clamping groove structure, while the opposite annular surface is a flat surface without a wavy clamping groove structure, and the flat surface is attached to the polar plate, which has better sealing effect. The planar outer contour shape of the first annular sealing member 31 and the second annular sealing member 32 is square; the planar contour shape of the first through hole 311 and the second through hole 321 is square; the through hole of the sealing member can also be adjusted to be circular or other shapes according to the adaptability of different electrode membrane assembly shapes; but in terms of sealing effect, the sealing assembly with a square outer frame and a square through hole has better effect.

[0073] The sealing assembly 3 is provided with recesses and protrusions only on one of the annular surfaces, and the annular surfaces with recesses and protrusions of the two annular sealing members are arranged opposite to each other and then engaged; the shapes of the two annular sealing members are the same; the shapes of the recesses and the protrusions on the two sealing members are the same; the number of recesses on the first annular sealing member 31 and the number of protrusions on the second annular sealing member 32 are the same or similar, and the corresponding positions of the first annular sealing member 31 and the second annular sealing member 32 can be matched and engaged with each other, so as to tightly attach the two sealing members and achieve the sealing effect; similarly, the number of protrusions on the first annular sealing member 31 and the number of recesses on the second annular sealing member 32 are the same or similar. In order to further improve the sealing effect, the number of recesses and protrusions arranged on the sealing assembly is optimized. In some embodiments, the arrangement density of the first recesses 312 on the surface of the first annular sealing member 31 is 6-8 pieces / cm 3 ; the arrangement density of the first protrusions 313 on the surface of the first annular sealing member 31 is 7-9 pieces / cm 3 ; the arrangement density of the second recesses 322 on the surface of the second annular sealing member 32 is 7-9 pieces / cm 3 ; and the arrangement density of the second protrusions 323 on the surface of the second annular sealing member 32 is 6-8 pieces / cm 3 . Controlling the number of recesses or protrusions on the sealing member within the above range can achieve optimal sealing effect and facilitate operation.

[0074] To further improve the sealing effect of the sealing assembly, the arrangement of the concave and convex parts on the sealing assembly is optimized. In some embodiments, the first concave parts 312 and the first convex parts 313 are arranged alternately on the surface of the first annular sealing member 31 (the concave and convex parts are adjacent); the first concave parts 312 and the first convex parts 313 are arranged in an array on the surface of the first annular sealing member 31; the second concave parts 322 and the second convex parts 323 are arranged alternately on the surface of the second annular sealing member 32 (the concave and convex parts are adjacent); the second concave parts 322 and the second convex parts 323 are arranged in a matrix on the surface of the second annular sealing member 32. By designing the concave and convex parts of the two annular sealing members in an array, the contact area of the sealing surface can be increased, providing more physical contact and improving the tightness and effectiveness of the seal. This complex surface structure can prolong the path of fluid or gas penetration, making it more difficult to directly penetrate the sealing surface; when the sealing member is subjected to external pressure, the arrayed concave and convex parts can better disperse stress and avoid excessive stress concentration, thereby reducing the wear of the sealing material and improving the durability and reliability of the seal; the arrayed concave and convex parts can also enhance the overall mechanical strength of the sealing assembly, making it more able to withstand external extrusion or impact forces; thereby achieving uniform distribution of the interlocking structure formed by the concave and convex parts, achieving uniform distribution of the sealing effect, so that the sealing assembly can not only achieve ideal sealing effect under static conditions, but also maintain its sealing performance under dynamic working conditions.

[0075] The sealing assembly of the present application improves the sealing performance by embedding the convex parts into the concave parts, and the shapes of the convex and concave parts are matched; the groove space profile of the concave part and the body profile of the convex part are matched; the shapes of the concave and convex parts affect the interlocking sealing effect of the two. In some embodiments, the cavity structure in the first concave part 312 is a semicircle, a spherical cap, or a quadrangular or regular quadrangular frustum, and from the perspective of a plane, the side view shape of the first concave part 312 is a semicircular arc, a circular arc, or an isosceles trapezoid; the first convex part 313 is a semicircle, a spherical cap, or a quadrangular or regular quadrangular frustum; from the perspective of a plane, the side view shape of the first convex part 313 is a semicircular arc, a circular arc, or an isosceles trapezoid; the first convex part 313 and the first concave part 312, and the second concave part 322 and the second convex part 323, have the same structure size; as Figure 3 and Figure 4The size of the concave and convex parts also affects the sealing effect. In some embodiments, the depth of the first concave part 312 is 0.04-0.06 mm, the height of the first convex part 313 is 0.05-0.07 mm, the depth of the second concave part 322 is 0.05-0.07 mm, and the height of the second convex part 323 is 0.04-0.06 mm. The height of the first convex part can be greater than or equal to the depth of the first concave part, as long as the depth of the first concave part and the height of the second convex part can match and occlude. For example, when the cavity in the first concave part is a semispherical shape, the diameter and depth of the semispherical cavity are the same as the diameter and height of the second convex part, such as the diameter of the semispherical cavity being 0.02-0.03 mm. When the cavity in the first concave part is a right quadrangular frustum, the bottom of the cavity is the upper bottom (short side) with a width of 0.03-0.05 mm, and the opening of the cavity is the lower bottom (long side) with a width of 0.05-0.07 mm, and the side of the trapezoid and the height of the trapezoid form an angle of 25-35°. The size of the cavity in the first concave part (width, height, and slope) can be smaller than or equal to the size of the first convex part. The depth or height of the concave and convex parts can be adjusted according to the actual situation, and the size is controlled within the above range, which can enhance the occlusion of the two sealing parts and enhance the sealing effect. When the concave and convex parts are designed to be similar to the structure of a semicircular body embedded in a semicircular cavity or a trapezoidal body embedded in a trapezoidal cavity, the sealing effect of the occlusion of the two components is better and the structure is stable.

[0076] To improve the sealing effect, the thickness of each sealing part is designed to adapt to the working environment of the two electrodes. In some embodiments, the thickness of the first annular sealing part 31 is 0.45-0.50 mm, and the radial width is 4.5-5.5 mm; the thickness of the second annular sealing part 32 is 0.30-0.40 mm. Controlling the thickness of the sealing part within the above range, the thickness difference formed as the elastic compression space of the sealing part; the thickness of the cathode side sealing part is greater than that of the anode side sealing part because the cathode side sealing part needs to withstand a more corrosive and high temperature and high pressure environment, and the anode side sealing part needs to withstand a larger deformation.

[0077] According to a second aspect of the present application, an AEM electrolysis cell unit is provided, which comprises, in order from the cathode side to the anode side, a cathode end plate 1, a cathode electrode plate 2, a first annular seal 31, an AEM electrode membrane assembly 4, a second annular seal 32, an anode electrode plate 5, and an anode end plate 6; wherein the AEM electrode membrane assembly 4 comprises, in order, a cathode gas diffusion layer 41, a cathode catalyst layer 42, an AEM electrode membrane 43, an anode catalyst layer 44, and an anode gas diffusion layer 45; wherein the first annular seal 31 and the second annular seal 32 are the first annular seal 31 and the second annular seal 32 of the sealing assembly 3 for the AEM electrolysis cell described above; wherein the AEM electrode membrane 43 is arranged in the region of the first through hole 311 of the first annular seal 31 and / or the second through hole 321 of the second annular seal 32, and the edge film of the non-catalyst layer of the AEM electrode membrane 43 is clamped in the interlocking structure formed by the engagement of the first annular seal 31 and the second annular seal 32; as shown in Figure 7

[0078] By tightly fixing the AEM electrode membrane assembly in the interlocking structure formed by the engagement of the two seals, the sealing effect and stability of the AEM electrode membrane assembly are significantly enhanced, and leakage of electrolyte or generated gas in the AEM electrolysis cell is avoided. At the same time, this engagement structure can allow a certain degree of dynamic deformation, which is beneficial for the long-term operation of the AEM electrolysis cell under various temperature and pressure conditions; for example, during the process of electrolyzing water to produce hydrogen, temperature changes can cause materials to expand or shrink, and the engagement structure can dynamically adjust the sealing gap to maintain a good sealing state; and the split engagement structure can use the most suitable material for each component, which is more suitable for different working environments on the electrode side.

[0079] In some embodiments, after the engagement of the two seals, the cathode gas diffusion layer 41 and the cathode electrode plate 2 are pressed together; and the anode gas diffusion layer 45 and the anode electrode plate 5 are pressed together, so that the electrode plates on both sides tightly press and fix the electrode membrane together to form an overall sealing structure.

[0080] In some embodiments, the AEM electrode membrane assembly 4 is provided with an electrolyte inlet 46 and an electrolyte outlet 47; and / or, the AEM electrode membrane assembly 4 is a CCS type electrode membrane assembly (catalyst layer coated on gas diffusion layer) or a CCM type electrode membrane assembly (catalyst layer coated on anion membrane). The sealing assembly 3 clamps the electrode membrane in the engagement structure without limiting the arrangement structure of the catalyst layers on both sides of the electrode membrane, so the sealing assembly 3 can be applied to different AEM electrode membrane assemblies.

[0081] According to a third aspect of the present application, a method for assembling the AEM electrolysis cell unit described above is provided, which comprises the following steps:

[0082] ​Step S1: sequentially stack the cathode end plate 1, the cathode electrode plate 2, the first annular sealing member 31, the AEM electrode membrane assembly 4, the second annular sealing member 32, the anode electrode plate 5, and the anode end plate 6 to form an initial electrolysis chamber; wherein the AEM electrode membrane assembly 4 comprises a cathode gas diffusion layer 41, a cathode catalyst layer 42, an AEM electrode membrane 43, an anode catalyst layer 44, and an anode gas diffusion layer 45 which are sequentially stacked; and the circumferential membrane edge of the AEM electrode membrane 43 is clamped between the first annular sealing member 31 and the second annular sealing member 32; as shown in Figure 6 ;

[0083] Step S2: apply extrusion force in opposite directions to the cathode end plate 1 and the anode end plate 6 of the initial electrolysis chamber to fasten and seal, to obtain a sealed AEM electrolysis chamber unit; wherein the first annular sealing member 31 and the second annular sealing member 32 are interlocked under the action of the extrusion force and fix the AEM electrode membrane 43 between the two annular sealing members; as shown in Figure 7 .

[0084] In some embodiments, in step S1, before the first annular sealing member 31 and the second annular sealing member 32 are interlocked, the thickness of the first annular sealing member 31 is greater than the total thickness of the cathode gas diffusion layer 41 and the cathode catalyst layer 42; preferably, the thickness of the first annular sealing member 31 is 1.125-1.25 times the total thickness of the cathode gas diffusion layer 41 and the cathode catalyst layer 42. The thickness of the sealing member is designed to be greater than the thickness of the gas diffusion layer (the thickness of the catalyst layer can be ignored), in order to reserve space for the sealing member to be compressed and interlocked for sealing; controlling the thickness difference between the two within the above range can match the space required for the sealing member to be interlocked and sealed.

[0085] In some embodiments, in step S1, before the first annular sealing member 31 and the second annular sealing member 32 are interlocked, the thickness of the second annular sealing member 32 is greater than the total thickness of the anode gas diffusion layer 45 and the anode catalyst layer 44 (the catalyst layer and the gas diffusion layer are integrated); preferably, the thickness of the second annular sealing member 32 is 1.5-2.0 times the total thickness of the anode gas diffusion layer 45 and the anode catalyst layer 44. Controlling the thickness difference between the two within the above range can match the space required for the sealing member to be interlocked and sealed.

[0086] In some embodiments, before the first annular seal 31 and the second annular seal 32 are engaged in step S1, the width of the first gap 7 between the cathode gas diffusion layer 41 and the cathode plate 2 is smaller than the width of the second gap 8 between the anode gas diffusion layer 45 and the anode plate 5. The width of the first gap 7 is for the first annular seal 31 to advance under the extrusion pressure towards the second annular seal 32, the first annular seal is mainly used for resisting the corrosion and high temperature and high pressure environment on the cathode side, and has small deformation and small space for advancing under the extrusion pressure; the second annular seal is mainly used for the large deformation of the anode side, and the second gap 8 required is larger, and the space for advancing under the extrusion pressure is larger; the gaps of different sizes are reserved to adapt to the elastic deformation and thickness of the annular seal.

[0087] In some embodiments, the thickness of the first annular seal 31 is 0.45-0.50 mm; the thickness of the cathode gas diffusion layer 41 is 0.38-0.42 mm; the thickness of the AEM electrode film 43 is 0.04-0.07 mm; the thickness of the second annular seal 32 is 0.30-0.40 mm; and the thickness of the anode gas diffusion layer 45 is 0.20-0.25 mm. By adjusting the ratio of the thickness of the specific seal and the thickness of the gas diffusion layer, the space required for the two seals to engage under the extrusion pressure can be accurately controlled.

[0088] According to a fourth aspect of the present application, an AEM electrolytic cell system is provided, which comprises a plurality of groups of AEM electrolytic cell units connected in series; the AEM electrolytic cell unit is the AEM electrolytic cell unit described above, or the AEM electrolytic cell unit obtained by the assembly method described above.

[0089] The present application will be further described in detail below in conjunction with specific examples, which cannot be understood as limiting the scope of the present application.

[0090] The raw materials of the embodiments of the present application are all prior art and can be purchased in the market.

[0091] Example 1

[0092] The sealing assembly for AEM electrolytic cell has a split plane structure as shown in Figure 1 and a side view as shown in Figure 2 The sealing assembly 3 comprises a first annular seal 31 made of polytetrafluoroethylene and having a square frame body as the outer contour, and a frame body radial width of 5.1 mm; the first annular seal 31 has a first through hole 311 in the form of a square with a thickness of 0.45 mm; a plurality of first recesses 312 and a plurality of first protrusions 313 are arranged on one annular surface of the first annular seal 31, and the arrangement density of the first recesses 312 and the first protrusions 313 is 7 / cm 3, all the concave parts and convex parts are alternately arranged in an array, and the opposite ring surface is a plane; wherein, the cavity structure in the first concave part 312 is a semispherical body with a diameter of 0.02 mm; the first convex part 313 is a semispherical body with a diameter of 0.025 mm;

[0093] The second annular sealing member 32 is made of thermoplastic polyester elastomer (TPEE), and has a square frame-shaped outer contour with a radial width of 5.1 mm; the second annular sealing member has a second through hole 321 with a thickness of 0.3 mm; one ring surface of the second annular sealing member is provided with a plurality of second concave parts 322 and a plurality of second convex parts 323; the setting density of the second concave parts 322 and the second convex parts 323 is 7 per cm 3 , all the concave parts and convex parts are alternately arranged in an array, and the opposite ring surface is a plane; wherein, the cavity structure in the first concave part 312 is a semispherical body with a diameter of 0.02 mm; the first convex part 313 is a semispherical body with a diameter of 0.025 mm; Figure 3

[0094] The first concave part 312 of the first annular sealing member 31 is used to engage with the second convex part 323 of the second annular sealing member 32; the first convex part 313 of the first annular sealing member 31 is used to engage with the second concave part 322 of the second annular sealing member 32, so that the first annular sealing member 31 and the second annular sealing member 32 form a close interlocking structure through engagement.

[0095] Example 2

[0096] Example 2 is different from Example 1 in that the cavity in the groove of the first concave part 312 is a regular quadrangular frustum, and the side profile of the regular quadrangular frustum is isosceles trapezoid, as shown in Figure 4 , the bottom of the groove of the first concave part 312 is the upper bottom (short side) with a width of 0.04 mm, the opening of the groove is the lower bottom (long side) with a width of 0.06 mm, the depth of the groove is 0.05 mm, and the side waist of the trapezoid and the height of the trapezoid form an angle of 30°; the first convex part 313 is a regular quadrangular frustum, and the side profile of the regular quadrangular frustum is isosceles trapezoid, the upper bottom (short side) of the convex part has a width of 0.05 mm, the lower bottom (long side) of the convex part has a width of 0.07 mm, the height of the convex part is 0.06 mm, and the side waist of the trapezoid and the height of the trapezoid form an angle of 25°. The groove structure of the second concave part 322 is the same as that of the first convex part 313, and the structure of the second convex part 323 is the same as that of the groove of the first concave part 312.

[0097] Example 3

[0098] Example 3 is different from Example 1 in that the thickness of the first annular sealing member 31 is replaced by 0.50 mm, and the thickness of the second annular sealing member 32 is replaced by 0.40 mm.

[0099] Example 4 ​

[0100] The assembly method of the AEM electrolysis chamber unit includes:

[0101] Step S1: As Figure 5 As shown, the cathode plate 1, cathode plate 2, first annular seal 31 (the first annular seal 31 of Example 1, 0.45 mm thick), AEM electrode film assembly 4, second annular seal 32 (the second annular seal 32 of Example 1, 0.3 mm thick), anode plate 5, and anode plate 6 are sequentially stacked to form an initial electrolysis chamber; wherein, the AEM electrode film assembly 4 (specifically a CCS type electrode film assembly) includes a cathode gas diffusion layer 41 (0.4 mm thick), a cathode catalyst layer 42, an AEM electrode film 43 (0.05 mm thick), an anode catalyst layer 44, and an anode gas diffusion layer 45 (0.2 mm) stacked sequentially; and the edge of the catalyst layer of the AEM electrode film 43 is sandwiched between the first annular seal 31 and the second annular seal 32; as Figure 6 As shown;

[0102] Step S2: Apply opposing compressive forces to the cathode end plate 1 and anode end plate 6 of the initial electrolysis chamber to tighten and seal them, thereby obtaining a sealed AEM electrolysis chamber unit; as shown Figure 7 As shown; wherein, the first annular seal 31 and the second annular seal 32 interlock under the action of extrusion force and fix the portion of the AEM electrode membrane 43 near the edge of the membrane in the circumferential direction between the two annular seals; the cathode gas diffusion layer 41 and the cathode plate 2 are pressed together; the anode gas diffusion layer 45 and the anode plate 5 are pressed together.

[0103] Example 5

[0104] The difference between Example 5 and Example 4 is that the AEM electrode membrane assembly type is replaced with a CCM type electrode membrane assembly.

[0105] Example 6

[0106] The difference between Example 6 and Example 4 is that the sealing component 3 is replaced with the sealing component 3 of Example 2.

[0107] Example 7

[0108] The difference between Example 7 and Example 4 is that the sealing component 3 is replaced with the sealing component 3 of Example 3.

[0109] Sealing test:

[0110] Liquid leak sealing was performed on the AEM electrolytic cells of Examples 4-7 by respectively supplying alkaline electrolyte to the AEM electrolytic cells. No liquid leakage was observed around the electrolytic cells. Then, current was applied to the AEM electrolytic cells, and oxygen gas detector was used to detect whether there was gas leakage on the anode side. No oxygen was detected by the oxygen gas detector within the oxygen limit. Hydrogen gas detector was used to detect whether there was gas leakage on the cathode side. No hydrogen was detected by the hydrogen gas detector within the hydrogen limit. Through verification, the sealing performance of the four AEM electrolytic cells was good.

[0111] The present application significantly enhances the sealing effect and stability of the AEM electrode membrane assembly by tightly fixing the AEM electrode membrane assembly in the interlocking structure formed by the occlusion of the two sealing members, thereby avoiding leakage of the electrolyte or generated gas in the AEM electrolytic cell. At the same time, the occlusion structure can allow a certain degree of dynamic deformation, which is conducive to the long-term operation of the AEM electrolytic cell under various temperature and pressure conditions.

[0112] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application are used to distinguish similar objects, and do not necessarily refer to a specific order or sequence. It should be understood that the terms used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than that described herein.

[0113] The above only describes the preferred embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A seal assembly for an AEM electrolytic cell, characterized in that, The AEM electrolytic cell uses a sealing assembly (3) comprising: a first annular seal (31) having a first through hole (311); a plurality of first recesses (312) and a plurality of first protrusions (313) are arranged on the annular surface of the first annular seal (31); a second annular seal (32) having a second through hole (321); a plurality of second recesses (322) and a plurality of second protrusions (323) are arranged on the annular surface of the second annular seal (32); wherein the first recesses (312) are used to engage with the second protrusions (323), and the first protrusions (313) are used to engage with the second recesses (322), so that the first annular seal (31) and the second annular seal (32) form an interlocking structure by engagement.

2. The seal assembly for an AEM electrolyzer of claim 1, wherein, a plurality of first recesses (312) and a plurality of first protrusions (313) are arranged on one of the annular surfaces of the first annular seal (31); and / or, a plurality of second recesses (322) and a plurality of second protrusions (323) are arranged on one of the annular surfaces of the second annular seal (32); and / or, the outer contour shapes of the first annular seal (31) and the second annular seal (32) are square, respectively; and / or, the contour shapes of the first through hole (311) and the second through hole (321) are square, respectively.

3. A seal assembly for an AEM electrolytic cell according to claim 1 or 2, characterised in that, The material of the first annular seal (31) is polytetrafluoroethylene; and / or, the material of the second annular seal (32) is thermoplastic polyester elastomer; and / or, the thickness of the first annular seal (31) is 0.45-0.50mm; and / or, the thickness of the second annular seal (32) is 0.30-0.40mm.

4. The seal assembly for an AEM electrolyzer cell of any one of claims 1 to 3, wherein, The first recesses (312) are arranged at a density of 6 to 8 per cm2of the surface of the first annular seal (31) 3 ; And / or, the first convex part (313) in the first annular seal (31) surface density is 7~9 / cm 3 ; and / or, the first recesses (312) and the first protrusions (313) are arranged alternately on the surface of the first annular seal (31); and / or, the first recesses (312) and the first protrusions (313) are arranged in a matrix on the surface of the first annular seal (31); and / or, the second recesses (322) are arranged at a density of 7 to 9 per cm2of the surface of the second annular seal (32) 3 ; And / or, the second convex part (323) in the second annular seal (32) surface density of 6-8 / cm 3 ; and / or, the second recesses (322) and the second protrusions (323) are arranged alternately on the surface of the second annular seal (32); and / or, the second recesses (322) and the second protrusions (323) are arranged in a matrix on the surface of the second annular seal (32).

5. The seal assembly for an AEM electrolyzer cell of any one of claims 1 to 4, wherein, The cavities in the first recesses (312) are semispherical, spherical crown or quadrangular prism, and the second protrusions (323) are semispherical, spherical crown or regular quadrangular prism, in turn; and / or, the first protrusions (313) are semispherical, spherical crown or regular quadrangular prism, and the cavities in the second recesses (322) are semispherical, spherical crown or regular quadrangular prism, in turn; and / or, the depth of the first recesses (312) and the height of the second protrusions (323) are the same and are 0.04-0.06mm; and / or, the height of the first protrusions (313) and the depth of the second recesses (322) are the same and are 0.05-0.07mm.

6. An AEM electrolysis cell unit characterized by, The AEM electrolysis chamber unit comprises, from the cathode side to the anode side, a cathode end plate (1), a cathode electrode plate (2), a first annular sealing element (31), an AEM electrode membrane assembly (4), a second annular sealing element (32), an anode electrode plate (5), and an anode end plate (6); wherein the AEM electrode membrane assembly (4) comprises, in sequence, a cathode gas diffusion layer (41), a cathode catalyst layer (42), an AEM electrode membrane (43), an anode catalyst layer (44), and an anode gas diffusion layer (45); The first annular sealing element (31) and the second annular sealing element (32) are respectively the first annular sealing element (31) and the second annular sealing element (32) of the sealing assembly (3) for the AEM electrolysis tank according to any one of claims 1 to 5. The AEM electrode membrane (43) is arranged in the region of the first through hole (311) of the first annular sealing element (31) and / or the second through hole (321) of the second annular sealing element (32), and the non-catalytic layer edge film edge of the AEM electrode membrane (43) is clamped in the interlocking structure formed by the occlusion of the first annular sealing element (31) and the second annular sealing element (32).

7. The AEM electrolysis cell unit of claim 6, wherein, The cathode gas diffusion layer (41) and the cathode electrode plate (2) are pressed together; And / or, the anode gas diffusion layer (45) and the anode electrode plate (5) are pressed together; And / or, the AEM electrode membrane assembly (4) is provided with an electrolyte inlet (46) and an electrolyte outlet (47); And / or, the AEM electrode membrane assembly (4) is a CCS type membrane electrode assembly or a CCM type membrane electrode assembly.

8. A method of assembling an AEM electrolysis cell unit as claimed in claim 6 or 7, characterised in that, The method comprises the following steps: Step S1: sequentially stacking a cathode end plate (1), a cathode electrode plate (2), a first annular sealing element (31), an AEM electrode membrane assembly (4), a second annular sealing element (32), an anode electrode plate (5), and an anode end plate (6) to form an initial electrolysis chamber; The AEM electrode membrane assembly (4) comprises, in sequence, a cathode gas diffusion layer (41), a cathode catalyst layer (42), an AEM electrode membrane (43), an anode catalyst layer (44), and an anode gas diffusion layer (45); and the non-catalytic layer edge film edge of the AEM electrode membrane (43) is clamped between the first annular sealing element (31) and the second annular sealing element (32); Step S2: applying a relative direction extrusion force to the cathode end plate (1) and the anode end plate (6) for fastening and sealing to obtain the sealed AEM electrolysis chamber unit; wherein the first annular sealing element (31) and the second annular sealing element (32) are interlocked under the action of the extrusion force to fix the AEM electrode membrane (43) between the two annular sealing elements.

9. The method of assembling an AEM electrolysis cell of claim 8, wherein, Preferably, the thickness of the first annular sealing member (31) is 1.125-1.25 times the total thickness of the cathode gas diffusion layer (41) and the cathode catalyst layer (42); Preferably, the thickness of the second annular sealing member (32) is 1.5-2.0 times the total thickness of the anode gas diffusion layer (45) and the anode catalyst layer (44); Preferably, the width of the first gap (7) between the cathode gas diffusion layer (41) and the cathode plate (2) is smaller than the width of the second gap (8) between the anode gas diffusion layer (45) and the anode plate (5); Preferably, the thickness of the first annular sealing member (31) is 0.45-0.50 mm; Preferably, the thickness of the cathode gas diffusion layer (41) is 0.38-0.42 mm; Preferably, the thickness of the AEM electrode film (43) is 0.04-0.07 mm; Preferably, the thickness of the second annular sealing member (32) is 0.30-0.40 mm; Preferably, the thickness of the anode gas diffusion layer (45) is 0.20-0.25 mm.

10. An AEM electrolytic cell system comprising a plurality of sets of AEM electrolytic cell units connected in series; characterized in that, The AEM electrolysis chamber unit is the AEM electrolysis chamber unit of claim 6 or 7, or the AEM electrolysis chamber unit obtained by the assembly method of claim 8 or 9.

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