Hydrogen production electrolytic cell pole frame sealing assembly and preparation method thereof

Abstract

The invention provides a hydrogen production electrolytic cell pole frame sealing assembly and a preparation method thereof. The hydrogen production electrolytic cell pole frame sealing assembly comprises a stainless steel pole frame, an adhesive layer arranged between the pole frame and a rubber layer and the rubber layer integrally formed with the pole frame. The method comprises the following steps: carrying out surface treatment, cleaning and degreasing on a bonding surface of a pole frame, and protecting a non-bonding surface; coating a Chemlok AP133 adhesive solution on the bonding surface in a dip-coating manner, and airing the Chemlok AP133 adhesive solution to form an adhesive film; mixing and preforming the ethylene propylene diene monomer, the butyl rubber, the reinforcing filler, the vulcanization system and the tackifying component; combining the rubber layer and the pole frame through the rubber film under the vacuumizing condition through die assembly, pressurization and vulcanization; and trimming, cleaning and drying the finished product. According to the scheme, the metal-rubber interface bonding stability and the sealing and insulating reliability can be improved, and the stacking assembly requirement of the electrolytic cell is met.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen production technology using electrolyzers, specifically relating to a sealing assembly for the electrode frame of a hydrogen production electrolyzer and its preparation method. Background Technology

[0002] Electrolysis of water to produce hydrogen is an important green hydrogen production technology, and its core equipment is the electrolyzer. Electrolyzers typically adopt a stacked structure, consisting of components such as electrode frames, end plates, electrode plates, and sealing elements assembled to form a sealed interface. Sealing performance is a necessary prerequisite for its stable operation and power enhancement.

[0003] In actual operation, electrolytic cells need to work for a long time under continuous preload conditions, and at the same time face comprehensive working conditions such as high pressure and strong acid or strong alkali media environment. This makes the sealing element not only meet the gas and liquid isolation requirements, but also need to maintain reliable sealing contact and insulation level under the action of electrolytic medium wetting, temperature fluctuation and long-term compression deformation.

[0004] In existing technologies, traditional electrolyzers often use polytetrafluoroethylene (PTFE) seals. However, with the development of electrolyzer hydrogen production technology, the limitations of its material properties have gradually become apparent: PTFE is prone to creep under continuous load, leading to an increase in the gap at the sealing interface over time and increasing the risk of leakage; at the same time, it is mostly physically bonded to the metal electrode frame, making it difficult to adapt to the micro-deformation during the electrolyzer stacking and assembly process, which may lead to leakage under long-term continuous load; in addition, although its volume resistivity is high, its surface easily adsorbs electrolyte ions, which may significantly reduce the actual insulation resistance, thus adversely affecting the safe operation and insulation reliability of the electrolyzer.

[0005] Rubber materials are widely used in sealing applications due to their elastic recovery capabilities. For the acid and alkali media and operating temperatures of electrolytic cells, EPDM rubber is one of the most commonly used rubber materials. However, standalone rubber seals have insufficient pressure resistance and relatively complex installation and assembly. Therefore, engineering often requires the development of integrated molding solutions for the electrode frame or plate and the rubber seal. However, EPDM rubber is a saturated non-polar rubber, making it difficult to form a stable and robust interface bond with metal electrode frames. In practice, complex surface polarization treatments and multi-component adhesive coating processes are usually required to improve bonding strength and consistency. However, multi-layer coating can easily result in excessively thick or uneven adhesive layers, further increasing the difficulty of dimensional consistency control and potentially affecting the assembly stability of the sealing interface.

[0006] On the other hand, as electrolytic cells develop towards larger sizes and higher power densities, metal skeleton components such as electrode frames exhibit the characteristics of thinner walls and higher precision assembly. For example, the thickness of the electrode frame may not exceed 1 mm, and its overall dimensions may be large, placing higher demands on warpage control. Although rubber-metal composites can be achieved through compression molding or injection molding, traditional rubber-metal composite processes often require multiple steps, resulting in low overall efficiency. Furthermore, under thin-walled metal skeleton conditions, manufacturing risks such as deformation or scratches are easily introduced, thereby reducing the engineering quality stability of integrated sealing components.

[0007] Therefore, there is an urgent need for a sealing assembly for the electrode frame of a hydrogen electrolyzer and its preparation method. Under the premise of meeting the requirements of the electrolysis medium environment and long-term load conditions, it should be able to take into account the reliable bonding of the metal and rubber interface, the long-term stability of sealing and insulation performance, and adapt to the requirements of flatness and consistency for the precision assembly of thin electrode frames. This would solve the problems of easy creep leakage, unstable interface bonding, complex process and limited consistency in the existing technology. Summary of the Invention

[0008] This invention provides a sealing assembly for the electrode frame of a hydrogen electrolyzer and its preparation method, in order to solve the problems in the prior art where the sealing assembly is prone to creep leakage under strong acid or strong alkali media and long-term pre-tightening load conditions, the metal-rubber interface is unstable, and the consistency of precision assembly of thin electrode frames is difficult to guarantee.

[0009] To achieve the above objectives, the technical solution of the present invention is as follows:

[0010] A method for preparing a sealing assembly for an electrode frame of a hydrogen electrolyzer includes the following steps:

[0011] A. Pre-treatment of the electrode frame: A stainless steel electrode frame is provided, and the bonding surface of the stainless steel electrode frame is treated and cleaned and degreased, while the non-bonding surface of the stainless steel electrode frame is protected.

[0012] B. Adhesive coating: Prepare Chemlok AP133 adhesive solution, dip and coat the bonding surface after step A, and let it dry to form an adhesive film on the bonding surface;

[0013] C. Rubber mixing and preforming: EPDM rubber is mixed with butyl rubber, reinforcing filler, vulcanization system and tackifying component to obtain compound rubber, and the compound rubber is preformed into rubber preforms that match the stainless steel pole frame.

[0014] D. Vacuum molding and vulcanization: The stainless steel pole frame and the rubber preform are placed in a mold, and the mold is closed and pressure vulcanized under vacuum conditions, so that the rubber preform and the bonding surface form an integrated rubber sealing layer through the adhesive film.

[0015] E. Post-processing: Trim, clean and dry the sulfided components to obtain the hydrogen electrolyzer electrode frame sealing assembly.

[0016] Furthermore, the protection of the non-adhesive surface in step A includes: applying a polymer protective film to the non-adhesive surface; and the cleaning and degreasing in step A includes: sequentially cleaning with gasoline and degreasing with ethyl acetate, immersing in anhydrous ethanol for 5 minutes and then drying with nitrogen.

[0017] Furthermore, the surface treatment of the bonding surface in step A includes sandblasting or chemical activation; wherein, the sandblasting uses 120-mesh white corundum sand and the sandblasting pressure is 0.5MPa, so that the surface roughness of the bonding surface is 3.2μm; the chemical activation treatment uses nitric acid-hydrofluoric acid solution to activate the bonding surface.

[0018] Furthermore, the Chemlok AP133 adhesive solution mentioned in step B is obtained by mixing Chemlok AP133 adhesive with anhydrous ethanol at a volume ratio of 1:1 or 1:0.8, and the drying conditions are drying at 25°C for 30 minutes, forming an adhesive film with a thickness of 2μm~4μm after drying.

[0019] Furthermore, the dip coating in step B is performed using the dip coating method, with an immersion speed of 10 mm / s and a lifting speed of 2 mm / s.

[0020] Furthermore, the compound in step C comprises, by weight percentage: 50% EPDM rubber, 30% butyl rubber, 15% carbon black N550, 2% vulcanizing agent DCP, and 3% resin tackifier; or by weight percentage: 36% EPDM rubber, 20% butyl rubber, and 2% nano alumina.

[0021] Furthermore, the mixing process in step C includes: a first-stage mixing at 60°C for 8 minutes, followed by a second-stage mixing at 40°C with the addition of a vulcanizing agent for 3 minutes, resulting in a sheet thickness of 1.5 mm ± 0.1 mm.

[0022] Furthermore, the vacuum molding vulcanization described in step D is performed on a vacuum flat vulcanizing machine, with a vacuum degree of −0.095 MPa maintained for 5 minutes after mold closing; the pressure vulcanization meets any of the following conditions:

[0023] (1) The mold temperature is 160℃±5℃, the vulcanization pressure is 12MPa±2MPa, and the vulcanization time is 18min±1min;

[0024] (2) After maintaining at 140℃ for 5 minutes, raise the temperature to 160℃ and maintain it for 15 minutes;

[0025] (3) Vulcanize at 150℃ for 30 min.

[0026] Furthermore, the post-processing in step E includes: trimming with a laser cutting machine with a trimming accuracy of ±0.05mm; ultrasonic cleaning at a frequency of 40kHz and cleaning at 50℃ for 10 minutes followed by rinsing with deionized water; drying in an 80℃ hot air circulating oven for 30 minutes and purging with nitrogen.

[0027] Furthermore, step E also includes: heat treatment at 120°C for 2 hours to release residual stress.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0029] The embodiments of the present invention employ a blended sealing system of EPDM rubber and butyl rubber, along with corresponding reinforcement and vulcanization systems, to ensure that the sealing layer maintains a relatively stable range of physical property changes under the influence of strong alkaline media and temperature, and is not prone to brittleness at low temperatures. At the same time, it maintains a high surface resistivity level, which is beneficial for maintaining the overall stability of sealing and insulation during long-term operation in high-pressure, strong acid or strong alkaline environments of electrolytic cells.

[0030] In this invention, an adhesive layer based on Chemlok AP133 is introduced between the stainless steel pole frame and the rubber sealing layer. Combined with sandblasting or pickling treatments on the pole frame bonding surface, a more stable interfacial bond can be formed between the metal and the saturated rubber. At the same time, the micron-sized adhesive film formed by dip coating helps to reduce assembly fluctuations caused by unevenness and excessive thickness of the adhesive layer, thereby improving the consistency and assembly adaptability of batch production. The relevant peel adhesion strength test results can reflect the reliability of the interfacial bond.

[0031] This invention combines metal surface gradient treatment, adhesive impregnation, and vacuum molding vulcanization to achieve denser filling and interface curing conditions for the rubber during molding. Post-processing methods such as trimming, cleaning, drying, and stress release further reduce residual stress and contamination risks, thus better meeting the flatness control requirements of thin electrode frames. Test results, including helium mass spectrometry leak detection, warpage, and stacking assembly errors, reflect improvements in airtightness and assembly consistency. Combined with accelerated aging life prediction results, this helps reduce maintenance frequency and leakage risks during electrolytic cell operation.

[0032] Of course, implementing the various technical solutions of this invention does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0034] Figure 1 This is a flowchart of a method according to an embodiment of the present invention;

[0035] Figure 2 This is a schematic cross-sectional view of the circular pole frame in an embodiment of the present invention;

[0036] Figure 3 These are comparative images of adhesive-treated surfaces according to embodiments of the present invention.

[0037] In the diagram, 1-polar frame, 2-adhesive layer, 3-rubber layer. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by associated similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods.

[0039] In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid the core parts of this application being overwhelmed by excessive description. For those skilled in the art, it is not necessary to describe these related operations in detail. They can fully understand the related operations based on the description in the specification and general technical knowledge in the field.

[0040] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0041] like Figure 2As shown, the hydrogen electrolyzer electrode frame sealing assembly of this embodiment of the invention is an integrated composite structure, mainly including an electrode frame 1, an adhesive layer 2 located between the electrode frame 1 and the rubber layer 3, and a rubber layer 3 bonded to the electrode frame 1. This structure is used to achieve gas-liquid isolation and insulation maintenance under the pre-tightening load of the electrolyzer stack assembly. The electrode frame 1 can be a stainless steel electrode frame with a thickness ≤1mm, an outer diameter of 100mm~500mm, and a warpage ≤0.1mm / m. The rubber layer 3 can be made of a blend of EPDM rubber and butyl rubber, and the adhesive layer 2 can be a film formed by Chemlok AP133 adhesive to enhance interfacial bonding.

[0042] Figure 3 The comparison of different surface treatments and adhesive coating schemes is shown: there are obvious differences in the surface condition of the metal before and after sandblasting, and the traditional adhesive primer and topcoat are prone to uneven coating and thick adhesive layer. However, the AP133 adhesive coating can achieve one-time molding and obtain a more uniform adhesive layer, which provides a more controllable interface basis for the stable bonding of the subsequent rubber layer 3 and the pole frame 1.

[0043] Example 1

[0044] A method for preparing a sealing assembly for an electrode frame of a hydrogen electrolyzer, see [link to documentation]. Figure 1 It includes the following steps:

[0045] Step A, Pre-treatment of the electrode frame: A SUS316L stainless steel electrode frame is selected as electrode frame 1, with a thickness of 0.8mm and an outer diameter of 300mm. To avoid contamination or scratches on the non-bonding surface during subsequent processing, the non-bonding surface of electrode frame 1 is first protected. This can be achieved by positioning and cutting the frame and then applying a polymer protective film, such as a 25μm thick polyimide high-temperature resistant tape or polyester film, with edge positioning accuracy controlled within ±0.2mm. Subsequently, the bonding surface is surface-treated using 120-mesh white corundum abrasive sandblasting at a pressure of 0.5MPa to achieve a surface roughness of Ra3.2μm. The rough morphology after sandblasting improves the mechanical interlocking of the adhesive film, thus providing conditions for stable adhesion of adhesive layer 2. After surface treatment, the bonding surface is cleaned and degreased. Cleaning and degreasing can include gasoline cleaning and ethyl acetate degreasing, and can be combined with 40kHz ultrasonic cleaning for 10 minutes, anhydrous ethanol immersion cleaning for 5 minutes, and nitrogen drying to reduce the impact of residual oil on the bonding strength.

[0046] Step B, Adhesive Coating: Prepare a Chemlok AP133 adhesive solution by mixing Chemlok AP133 metal adhesive with anhydrous ethanol at a volume ratio of 1:1 and stirring for 30 minutes until a transparent homogeneous phase is formed. Dip the adhesive layer treated in Step A into the solution at a dipping speed of 10 mm / s and a pulling speed of 2 mm / s. After dipping, allow it to air dry at 25°C for 30 minutes to form an adhesive film with a thickness of 2 μm to 3 μm, resulting in adhesive layer 2. Compared to traditional multi-layer coating methods, this method produces a thinner and more uniform adhesive film, which helps reduce assembly fluctuations caused by excessively thick adhesive layers.

[0047] Step C, Rubber Mixing and Preforming: EPDM rubber, butyl rubber, reinforcing fillers, vulcanization system, and tackifying components are mixed to obtain a compound. The mixing process can be a two-stage process: the first stage involves mixing at 60°C for 8 minutes, and the second stage involves adding the vulcanizing agent at 40°C and mixing for 3 minutes, resulting in a sheet thickness of 1.5 mm ± 0.1 mm. After mixing, the compound is cut and preformed into rubber preforms that match the electrode frame 1. This two-stage mixing process helps ensure uniform dispersion of the reinforcing fillers and vulcanization system, thereby improving the consistency of the rubber layer 3 in terms of compression retention and resistance to media.

[0048] Step D, Vacuum Compression Vulcanization: The protective film-coated electrode frame 1 and the rubber preform are placed together in the mold cavity. A vacuum flatbed vulcanizing machine is used for automatic mold closing, and vulcanization is performed under vacuum conditions. Before vulcanization, the mold is preheated to 160℃, the vulcanization pressure is 12MPa, the vulcanization time is 18min, and the vacuum degree is −0.095MPa, maintained for 5min after mold closing. Vacuum conditions reduce interfacial air trapping and molding porosity. Combined with pressure vulcanization, this allows the rubber to fill the cavity more fully and solidify with the rubber film, ultimately forming a rubber layer 3 integrated with the electrode frame 1. After mold opening, the component is ejected and allowed to cool naturally to below 60℃.

[0049] Step E: Post-processing: Trim the edges of the vulcanized components using a laser cutter to remove burrs, with a trimming accuracy of ±0.05mm. Then, clean and dry. Cleaning can be performed using 40kHz ultrasonic cleaning at 50℃ for 10 minutes, followed by rinsing with deionized water. Drying can be done in an 80℃ hot air circulating oven for 30 minutes, followed by nitrogen purging to remove residual moisture, resulting in the hydrogen electrolyzer electrode frame sealing assembly. This post-processing helps reduce the adverse effects of surface residue and moisture on insulation performance and improves the cleanliness consistency of subsequent assembly.

[0050] To verify the overall performance of the basic component, material and finished product tests can be performed: The volume change rate after immersion in 30% KOH solution at 70℃ for 72 hours is approximately 2.3%; the surface resistivity is approximately 5 × 10⁻⁶. 13Ω; the adhesive strength tested by the 90° peel method is approximately 6.2 kN / m; under helium mass spectrometry leak detection conditions with a pressure difference of 0.5 MPa, the leakage rate can reach 3.2 × 10⁻⁶. ⁻8 The results are on the order of Pa·m³ / s. These results reflect the usable engineering stability of this embodiment in terms of dielectric resistance, insulation retention, interfacial bonding, and hermeticity.

[0051] Example 2

[0052] Without changing the basic process of Example 1, in order to enhance the pressure retention ability of the sealing layer under higher preload, the adhesive layer thickness, rubber formulation and vulcanization curve were synergistically optimized.

[0053] A method for preparing a sealing assembly for an electrode frame of a hydrogen electrolyzer includes the following steps:

[0054] Step A: The pretreatment of the electrode frame is the same as in Example 1, including applying a polymer protective film to the non-adhesive surface and sandblasting, cleaning, and degreasing the adhesive surface. Consistent sandblasting and cleaning are still fundamental to ensuring consistent bonding at the interface.

[0055] Step B: Adjust the volume ratio of AP133 to ethanol to 1:0.8 to increase the thickness of the dried film to 4 μm. Appropriately increasing the film thickness can improve the load-bearing capacity and process tolerance of the interfacial bonding layer to some extent, and reduce the sensitivity of micro-gaps to localized leakage.

[0056] Step C: Regarding the rubber system, the EPDM content is increased to 36%, the IIR content is reduced to 20%, and 2% nano-alumina is added. This adjustment allows rubber layer 3 to maintain its resistance to media and low-temperature performance while improving its compressive strength and long-term compression stability, making it more suitable for working conditions with higher preload.

[0057] Step D: The vulcanization process adopts a stepped heating method, holding at 140℃ for 5 minutes, then raising to 160℃ and holding for 15 minutes. By reducing the transient thermal shock during the heating process, the accumulation of internal stress can be reduced, and the interfacial stress concentration caused by vulcanization shrinkage can be reduced, thereby improving the stability of the bond between the rubber layer 3 and the pole frame 1.

[0058] Step E: The post-processing is the same as in Example 1, including trimming, ultrasonic cleaning, deionized water rinsing, hot air drying and nitrogen purging.

[0059] In terms of performance verification, the surface resistivity of Example 2 is approximately 6.7 × 10⁻⁶. 13 Ω, with an adhesive strength of approximately 6.5 kN / m; helium mass spectrometry leak detection (0.5 MPa pressure difference) shows a leakage rate of up to 1.8 × 10⁻⁶. ⁻8 Pa·m 3The result is on the order of / s. This demonstrates that the optimized combination of film thickness and formulation with step vulcanization results in more stable performance in terms of insulation retention, interfacial bonding, and airtightness.

[0060] Example 3

[0061] To address the higher requirements for warpage and dimensional stability in thin-walled pole frame assembly, this embodiment targets a pole frame thickness of 1mm and a warpage control of ≤0.05mm / m. Adjustments are made to the surface treatment method and thermal process control to reduce the shape and position risks of thin-walled pole frames.

[0062] A method for preparing a sealing assembly for an electrode frame of a hydrogen electrolyzer includes the following steps:

[0063] Step A: While continuing to protect the non-bonded surfaces with a polymer protective film, replace the sandblasting treatment on the bonded surfaces with chemical activation treatment, using a solution of nitric acid and hydrofluoric acid to activate the bonded surfaces. Compared to sandblasting, chemical activation can reduce the impact of external forces on the thin-walled pole frame, reducing the probability of micro-deformation caused by sandblasting force from the source.

[0064] Step B: The adhesive coating can be performed according to the dip-coating and drying method of Example 1 to form a uniform adhesive film, providing an interface basis for the integrated molding of rubber layer 3.

[0065] Step C: Rubber mixing and preforming can be carried out in accordance with the two-stage mixing and sheet thickness control of Example 1, so that the rubber preform has a relatively stable thickness and fluidity before molding.

[0066] Step D: Low-temperature vulcanization is adopted, vulcanizing at 150℃ for 30 minutes to reduce the impact of thermal stress and thermal deformation on pole frame warpage. For thin-walled pole frames, reducing the peak vulcanization temperature and appropriately extending the holding time helps to reduce the deformation accumulation caused by temperature gradient.

[0067] Step E: In addition to trimming, cleaning, and drying, post-processing includes a secondary heat treatment step, where the components are placed in a 120℃ oven for 2 hours to release residual stress. Components obtained through this process exhibit a measured warpage of 0.04 mm / m, and the stacking assembly error can be controlled within 0.1 mm, meeting the flatness and consistency requirements for stacking and assembling larger electrolytic cells.

[0068] Meanwhile, in Example 3, the leakage rate reached 2.5 × 10⁻⁶ under helium mass spectrometry leak detection conditions (0.5 MPa pressure difference). ⁻8 Pa·m 3 The / s level indicates that a usable level of airtightness can still be maintained even with enhanced form and position control.

[0069] To verify the feasibility and stability of the electrode frame sealing assembly and its preparation method of the present invention, the applicant systematically evaluated Examples 1-3 through material performance testing and finished product performance testing in the original documents. At the material level, based on indicators such as tensile properties, hardness, performance retention after hot air aging, compression set, volume change rate and hardness change under strong alkaline media, low-temperature brittleness temperature, surface resistivity, and peel adhesion strength between metal and rubber, the results show that the rubber systems of the three examples can still maintain a relatively stable range of mechanical and dimensional changes under the influence of strong alkaline media and temperature, and possess usable insulation retention capacity and interfacial bonding strength. Simultaneously, the relevant environmental compliance tests were passed, and accelerated aging life prediction showed a long service life. At the finished product level, helium mass spectrometry leak detection was conducted under specified pressure difference conditions. The leakage rate of each example met the judgment requirements of tooling helium detection, reflecting the airtightness level of the integrated molding assembly. Furthermore, for the thin electrode frame adaptation process, the measured warpage data reflects its good control effect on shape and position accuracy.

[0070] Table 1: Performance Test Data for Examples 1-3

[0071] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for preparing a sealing assembly for an electrode frame of a hydrogen electrolyzer, characterized in that, Includes the following steps: A. Pre-treatment of the electrode frame: A stainless steel electrode frame is provided, and the bonding surface of the stainless steel electrode frame is treated and cleaned and degreased, and the non-bonding surface of the stainless steel electrode frame is protected. B. Adhesive coating: Prepare Chemlok AP133 adhesive solution, dip and coat the bonding surface after step A, and let it dry to form an adhesive film on the bonding surface; C. Rubber mixing and preforming: EPDM rubber is mixed with butyl rubber, reinforcing filler, vulcanization system and tackifying component to obtain compound rubber, and the compound rubber is preformed into rubber preforms that match the stainless steel pole frame. D. Vacuum molding and vulcanization: The stainless steel pole frame and the rubber preform are placed in a mold, and the mold is closed and pressure vulcanized under vacuum conditions, so that the rubber preform and the bonding surface form an integrated rubber sealing layer through the adhesive film. E. Post-processing: Trim, clean and dry the sulfided components to obtain the hydrogen electrolyzer electrode frame sealing assembly.

2. The preparation method according to claim 1, characterized in that, The protection of the non-adhesive surface in step A includes: applying a polymer protective film to the non-adhesive surface; and the cleaning and degreasing in step A includes: sequentially cleaning with gasoline and degreasing with ethyl acetate, immersing in anhydrous ethanol for 5 minutes and then drying with nitrogen.

3. The preparation method according to claim 1, characterized in that, Step A involves surface treatment of the bonding surface, including sandblasting or chemical activation. The sandblasting uses 120-mesh white corundum sand at a pressure of 0.5 MPa to achieve a surface roughness of 3.2 μm. The chemical activation involves activating the bonding surface with a nitric acid-hydrofluoric acid solution.

4. The preparation method according to claim 1, characterized in that, The Chemlok AP133 adhesive solution mentioned in step B is obtained by mixing Chemlok AP133 adhesive with anhydrous ethanol at a volume ratio of 1:1 or 1:0.8, and the drying conditions are to dry at 25°C for 30 minutes, forming an adhesive film with a thickness of 2μm~4μm after drying.

5. The preparation method according to claim 1, characterized in that, The dip coating in step B is performed using the dip coating method, with an immersion speed of 10 mm / s and a lifting speed of 2 mm / s.

6. The preparation method according to claim 1, characterized in that, The compound described in step C comprises, by weight percentage: 50% EPDM rubber, 30% butyl rubber, 15% carbon black N550, 2% vulcanizing agent DCP, and 3% resin tackifier; or by weight percentage: 36% EPDM rubber, 20% butyl rubber, and 2% nano alumina.

7. The preparation method according to claim 1, characterized in that, The mixing process in step C includes: a first-stage mixing at 60°C for 8 minutes, followed by a second-stage mixing at 40°C with the addition of a vulcanizing agent for 3 minutes, resulting in a sheet thickness of 1.5 mm ± 0.1 mm.

8. The preparation method according to claim 1, characterized in that, The vacuum molding vulcanization described in step D is performed on a vacuum flat vulcanizing machine with a vacuum degree of −0.095 MPa and maintained for 5 minutes after mold closing; the pressure vulcanization meets any of the following conditions: (1) The mold temperature is 160℃±5℃, the vulcanization pressure is 12MPa±2MPa, and the vulcanization time is 18min±1min; (2) After maintaining at 140℃ for 5 minutes, raise the temperature to 160℃ and maintain it for 15 minutes; (3) Vulcanize at 150℃ for 30 min.

9. The preparation method according to claim 1, characterized in that, The post-processing described in step E includes: trimming with a laser cutting machine with a trimming accuracy of ±0.05mm; ultrasonic cleaning at a frequency of 40kHz and cleaning at 50℃ for 10 minutes followed by rinsing with deionized water; drying in an 80℃ hot air circulating oven for 30 minutes and then purging with nitrogen.

10. The preparation method according to claim 1, characterized in that, Step E also includes: heat treatment at 120°C for 2 hours to release residual stress.

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