Integrated membrane electrode assembly and alkaline electrolytic cell

Abstract

The utility model discloses an integrated membrane electrode assembly and an alkaline electrolytic bath, the integrated membrane electrode assembly comprises a diaphragm, the diaphragm comprises a first surface and a second surface which are arranged oppositely, and the diaphragm is provided with an electrolyte channel communicating the first surface and the second surface, the diaphragm comprises an electrolyte channel area located in the middle and a fixed area surrounding the electrolyte channel area; the electrode is arranged on the first surface and / or the second surface, and the electrode covers the fixed area; and the first plastic layer is arranged in the electrolyte channel of the fixing area, and the first plastic layer extends to the first surface and / or the second surface so as to fix the diaphragm and the electrode. The diaphragm and the electrode are bonded and fixed through the first plastic layer, so that integrated design is realized, the assembly process and difficulty are effectively reduced, the assembly cost is reduced, the improvement of the assembly consistency and precision of the electrolytic cell is facilitated, and the overall efficiency of the electrolytic cell, the gas purity and the stability of the product quality are improved.

Description

Technical Field

[0001] This application belongs to the field of alkaline electrolyzer technology, specifically relating to an integrated membrane electrode assembly and an alkaline electrolyzer. Background Technology

[0002] The electrolyzer, as the main component of an alkaline water electrolysis system, provides the site for hydrogen and oxygen evolution reactions, and is also the main source of cost, energy consumption, and operation and maintenance. An electrolyzer is mainly assembled from hundreds of parts, including end plates, electrode frames, electrode plates, electrodes, diaphragms, and sealing gaskets. It comprises dozens or even hundreds of electrolysis chambers, connected together by screws and end plates to form a cylindrical structure.

[0003] Currently, the components of an electrolyzer are all independent structures. During the assembly process, these components need to be stacked to form an electrolyzer unit. It is crucial to ensure that the position and dimensions of each component meet design requirements and that the connections between them are secure, stable, and well-sealed. The assembly of numerous membrane electrode assemblies is the most critical and important part. The stacking accuracy is affected by the operator's skill level, often making it difficult to guarantee high precision and consistency in assembly. This significantly impacts the overall efficiency of the electrolyzer and the stability of product quality. Furthermore, the assembly process consumes considerable manpower and time, especially in large-scale electrolyzer assembly scenarios where each component requires robotic arms for handling and assembly, resulting in substantial assembly costs. Utility Model Content

[0004] The purpose of this application is to provide an integrated membrane electrode assembly and an alkaline electrolyzer to solve the technical problem that the components of the existing electrolyzer are all independent structures, which makes it difficult to ensure high precision and consistency in assembly, greatly affects the overall efficiency of the electrolyzer and the stability of product quality, and the assembly process consumes a lot of manpower and time, resulting in high assembly costs.

[0005] To achieve the above objectives, the first aspect of this application provides an integrated membrane electrode assembly, comprising:

[0006] A diaphragm includes a first surface and a second surface disposed opposite to each other, and an electrolyte channel is arranged on the diaphragm to connect the first surface and the second surface. The diaphragm includes an electrolyte channel region located in the middle and a fixed region surrounding the electrolyte channel region.

[0007] Electrodes are disposed on the first surface and / or the second surface, the electrodes covering the fixed area;

[0008] A first plastic layer is disposed within the electrolyte channel of the fixed area, and the first plastic layer extends to the first surface and / or the second surface to fix the diaphragm and the electrode.

[0009] In one or more embodiments, the electrode includes a cathode and an anode disposed on the first surface and the second surface, respectively, and the first plastic layer extends to the first surface and the second surface.

[0010] In one or more embodiments, the first plastic layer is a polyphenylene sulfone resin layer, a polysulfone layer, or a polyethersulfone layer.

[0011] In one or more embodiments, the first plastic layer extends to a depth of 0.5 to 0.8 mm within the electrolyte channel.

[0012] In one or more embodiments, the width of the fixing region extending radially in the diaphragm is 5 to 20 mm.

[0013] In one or more embodiments, the diaphragm further includes an extensional region surrounding the fixed region, the extensional region having a radial width of 7 to 15 mm in the diaphragm.

[0014] In one or more embodiments, the outer edge of the electrode overlaps with the orthographic projection of the outer edge of the fixing region.

[0015] In one or more embodiments, an elastic mesh is further included on the side of the electrode facing away from the diaphragm, the outer edge region of the elastic mesh being fixed to the electrode.

[0016] In one or more embodiments, the elastic mesh includes a welding area disposed on its outer edge, the welding area being welded and fixed in close contact with the electrode, the welding area overlapping the orthographic projection of the fixing area.

[0017] In one or more embodiments, the elastic mesh includes an adhesive region disposed at its outer edge, and the integrated membrane electrode assembly further includes a second plastic layer disposed between the adhesive region and the electrode, the second plastic layer being a polyphenylene sulfone resin layer, a polysulfone layer, or a polyethersulfone layer.

[0018] In one or more embodiments, a sealing gasket is further included on the side of the elastic mesh facing away from the diaphragm, the sealing gasket having a hollowed-out center and the inner edge region of the sealing gasket being fixed to the elastic mesh.

[0019] In one or more embodiments, the inner edge of the sealing gasket overlaps with the orthographic projection of the inner edge of the fixing area.

[0020] In one or more embodiments, an annular groove is arranged on the inner edge region of one side of the sealing gasket, and the elastic mesh is embedded in the annular groove.

[0021] In one or more embodiments, a first adhesive layer and a second adhesive layer are further included. The first adhesive layer is disposed on the side of the sealing gasket facing the elastic mesh, and the second adhesive layer is disposed on the side of the elastic mesh facing the sealing gasket. The first adhesive layer and the second adhesive layer cooperate to fix the sealing gasket and the elastic mesh. The first adhesive layer is a soluble polytetrafluoroethylene resin layer, and the second adhesive layer is a polyphenylene sulfone layer, a polysulfone layer, a polyethersulfone layer, or a polyphenylene sulfide layer.

[0022] In one or more embodiments, the integrated membrane electrode assembly further includes a snap-fit ​​element for securing the sealing gasket and the elastic mesh.

[0023] To achieve the above objectives, a second aspect of this application provides a method for fabricating the integrated membrane electrode assembly described in any of the above embodiments, comprising:

[0024] A plastic solute is added to a solvent, and the mixture is heated and stirred to dissolve the plastic solute, thereby obtaining a plastic adhesive.

[0025] The plastic adhesive is evenly applied to the outer edge of one side of the electrode or the outer edge of one side of the diaphragm. Then the electrode and the diaphragm are bonded together with the plastic adhesive and clamped in place. After that, the electrode is left to stand, soaked in water, and dried in sequence to form the first plastic layer.

[0026] In one or more embodiments, the plastic solute is polyphenylene sulfone resin, polysulfone, or polyethersulfone, and the solvent is N-methylpyrrolidone, dimethylformamide, dimethylacetamide, or dimethyl sulfoxide.

[0027] In one or more embodiments, the mass fraction of the plastic solute in the plastic adhesive is 5% to 50%.

[0028] In one or more embodiments, the settling time is 3 to 30 minutes.

[0029] In one or more embodiments, the soaking time is 2 to 12 hours.

[0030] To achieve the above objectives, a second aspect of this application provides an alkaline electrolytic cell, including a cell body and several integrated membrane electrode assemblies as described in any of the above embodiments, wherein the integrated membrane electrode assemblies are arranged in a stacked manner within the cell body.

[0031] The advantages of this application, which differ from existing technologies, are:

[0032] This application uses a first plastic layer to bond and fix the diaphragm and electrodes together, achieving an integrated design. The first plastic layer does not introduce additional resistance and will not adversely affect the diaphragm during operation. This effectively reduces assembly steps and difficulty, lowers assembly costs, and helps improve the assembly consistency and precision of the electrolytic cell, thereby improving the overall efficiency, gas purity, and product quality stability of the electrolytic cell. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application 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 recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of one embodiment of the integrated membrane electrode assembly of this application;

[0035] Figure 2 This is a cross-sectional structural schematic diagram of one embodiment of the integrated membrane electrode assembly of this application;

[0036] Figure 3 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0037] Figure 4 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0038] Figure 5 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0039] Figure 6 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0040] Figure 7 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0041] Figure 8 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application;

[0042] Figure 9 This is a schematic flowchart of one embodiment of the preparation method of the integrated membrane electrode assembly of this application;

[0043] Figure 10 This is a graph showing the cell voltage data from the stacking test of Example 2 of this application.

[0044] As shown in the figure:

[0045] 100; 101; 102; 103; 104; 105; 106; 107;

[0046] First plastic layer 200;

[0047] Electrode 300; Cathode 301; Anode 302;

[0048] Elastic mesh 400; Welding zone 401; Adhesive zone 402;

[0049] The second plastic layer is 500.

[0050] Sealing gasket 600; Annular groove 601;

[0051] First adhesive layer 700;

[0052] Second adhesive layer 800. Detailed Implementation

[0053] To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of this application.

[0054] The components of existing electrolyzers are all independent structures. In particular, a large number of membrane electrode assemblies need to be stacked and assembled into small cell units of the electrolyzer in sequence. It is difficult to ensure high precision and consistency in assembly, which greatly affects the overall efficiency of the electrolyzer and the stability of product quality. Moreover, the assembly process consumes a lot of manpower and time, resulting in high assembly costs.

[0055] However, there is currently no solution for integrating the electrodes of the membrane module. The main reasons are: 1. Each component in the alkaline electrolyzer needs to operate under high pressure, high temperature and strong alkalinity for a long time. Conventional integrated component solutions, such as conventional adhesives, are not suitable for the above environment; 2. Conventional integrated solutions may introduce resistance, reduce durability or affect gas purity, and are not suitable for alkaline electrolyzers.

[0056] To address the aforementioned issues, the applicant has developed an integrated membrane electrode assembly. This assembly integrates the membrane electrode components, effectively reducing assembly steps and complexity, improving assembly precision and consistency, and consequently enhancing the overall efficiency and product quality of the electrolyzer while reducing assembly costs.

[0057] Please see Figure 1 and Figure 2 , Figure 1 This is a schematic diagram of one embodiment of the integrated membrane electrode assembly of this application. Figure 2 This is a cross-sectional structural schematic diagram of one embodiment of the integrated membrane electrode assembly of this application.

[0058] like Figure 1 and Figure 2 As shown, the integrated membrane electrode assembly includes a diaphragm 100 and electrodes 300 disposed on the surface of the diaphragm 100. The electrodes 300 include a cathode 301 and an anode 302 disposed on a first surface 101 and a second surface 102 of the diaphragm 100, respectively.

[0059] The interior of the diaphragm 100 is uniformly arranged with electrolyte channels 103 that connect the first surface 101 and the second surface 102. The diaphragm 100 includes an electrolyte channel region 104 located in the middle and a fixed region 105 surrounding the electrolyte channel region 104.

[0060] In the fixed area 105, a first plastic layer 200 is arranged in the electrolyte channel 103. The first plastic layer 200 extends to the first surface 101 and the second surface 102, thereby fixing the diaphragm 100 and the electrode 300.

[0061] In this embodiment, the first plastic layer 200 is evenly distributed throughout the electrolyte channel 103 of the fixing area 105. At this time, the extension depth of the first plastic layer 200 in the electrolyte channel 103 is equal to the length of the electrolyte channel 103 of the diaphragm 100, that is, the thickness of the diaphragm 100. In other embodiments, the first plastic layer 200 can also be divided into two mutually isolated layers, each extending to one side surface to fix the electrode 300 on one side, which can also achieve the effect of this embodiment.

[0062] Specifically, in one embodiment, the extension depth of the first plastic layer 200 within the electrolyte channel 103 can be 0.5 to 0.8 mm; in other embodiments, the extension depth of the first plastic layer 200 can be adjusted based on actual working conditions for diaphragms 100 of different thicknesses, and the effects of this embodiment can be achieved in all cases.

[0063] In one embodiment, the first plastic layer 200 can be a polyphenylene sulfone resin layer, a polysulfone layer, or a polyethersulfone layer. The above-mentioned plastic materials can be applied to high pressure, high temperature, and strong alkaline environments, effectively ensuring the stability of each component under long-term working conditions, while not introducing additional resistance or affecting electrolysis efficiency.

[0064] In one embodiment, the radial extension width of the fixing region 105 in the diaphragm 100 can be 5 to 20 mm, thereby reducing the occupation of the electrolyte channel 103 of the diaphragm 100 while ensuring the stability of the fixing, and avoiding affecting the electrolysis efficiency.

[0065] In this embodiment, the outer edge of the first plastic layer 200 overlaps with the orthographic projection of the outer edge of the electrode 300. In other embodiments, the outer edge of the first plastic layer 200 may partially overflow the outer edge of the electrode 300, or the outer edge of the first plastic layer 200 may be completely covered by the electrode 300, as long as the fixation stability of the electrode 300 and the diaphragm 100 can be guaranteed.

[0066] In this embodiment, the integrated membrane electrode assembly includes a cathode 301 and an anode 302 arranged on both sides of the diaphragm 100. The first plastic layer 200 extends to the first surface 101 and the second surface 102 to simultaneously fix the electrodes 300 on both sides, thereby forming a three-in-one membrane electrode assembly. In other embodiments, the integrated membrane electrode assembly may also include only a cathode 301 arranged on one side of the diaphragm 100. In this case, the first plastic layer 200 may also extend only to the side of the diaphragm 100 where the electrodes 300 are arranged, which can also achieve the effect of this embodiment.

[0067] In this embodiment, the diaphragm 100, cathode 301, and anode 302 are all circular structures, and the fixing region 105 extends along the outer edge of the diaphragm 100 in an annular structure. In other embodiments, the diaphragm 100, cathode 301, and anode 302 may not be circular, and correspondingly, the shape of the fixing region 105 can be adjusted based on the shape of the diaphragm 100. For an example, please refer to [link to example]. Figure 3 , Figure 3 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application. The diaphragm 100, cathode 301, and anode 302 can also be matching square structures, and the fixing region 105 can be a square annular structure matching the diaphragm 100; or, please refer to Figure 4 , Figure 4 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application. The diaphragm 100, cathode 301 and anode 302 can also be matching arched structures, the fixing area 105 can be an arched annular structure matching the diaphragm 100, etc., all of which can achieve the effect of this embodiment.

[0068] To ensure airtightness and electrochemical efficiency, in this embodiment, the diaphragm 100 extends beyond the outer edge of the electrode 300, and the diaphragm 100 also includes an extensional region 106 surrounding the fixed region 105.

[0069] The width of the epitaxial region 106 can be adjusted based on the actual size of the electrolytic cell.

[0070] Specifically, in one embodiment, the radial extension width of the epitaxial region 106 in the diaphragm 100 can be 7 to 15 mm.

[0071] Of course, in other embodiments, the size of the diaphragm 100 can be set to be exactly the same as that of the electrode 300 based on actual needs, which can also achieve the effect of this embodiment.

[0072] In the above embodiments, the integrated membrane electrode assembly integrates a diaphragm 100 and an electrode 300. In another embodiment, the integrated membrane electrode assembly may further integrate an elastic mesh 400. Please refer to [link to relevant documentation]. Figure 5 and Figure 6 , Figure 5 This is a schematic diagram of another embodiment of the integrated membrane electrode assembly of this application. Figure 6 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application.

[0073] like Figure 5 and Figure 6 As shown, in this embodiment, the integrated membrane electrode assembly also includes an elastic mesh 400 arranged on the side of the electrode 300 facing away from the diaphragm 100, and the outer edge region of the elastic mesh 400 is fixedly connected to the electrode 300.

[0074] In this embodiment, the outer edge region of the elastic mesh 400 is welded and fixed to the electrode 300. Specifically, the outer edge region of the elastic mesh 400 can be welded to the electrode 300 by a roll welding machine, thereby forming a welding area 401 that is in close contact with the electrode 300 on the outer edge of the elastic mesh 400.

[0075] In order to maximize the performance of the components, in this embodiment, the orthographic projections of the welding area 401 and the fixing area 105 are overlapped.

[0076] In other embodiments, the elastic mesh 400 may also be fixed to the electrode 300 in other ways; for example, please refer to [link to relevant documentation]. Figure 7 , Figure 7 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application.

[0077] like Figure 7 As shown, in this embodiment, the elastic mesh 400 may include an adhesive area 402 arranged on its outer edge. A second plastic layer 500 may be provided between the adhesive area 402 and the electrode 300, and the elastic mesh 400 and the electrode 300 are fixed by the second plastic layer 500.

[0078] In one embodiment, the material of the second plastic layer 500 can be the same as that of the first plastic layer 200, that is, the second plastic layer 500 can be a polyphenylene sulfone resin layer, a polysulfone layer or a polyethersulfone layer.

[0079] The thickness of the second plastic layer 500 can be set based on actual needs, ensuring adhesion strength while avoiding excessive thickness that could affect the stable contact between the elastic mesh 400 and the electrode 300. For example, in one embodiment, the thickness of the second plastic layer 500 can be 0.5 to 0.8 mm.

[0080] In this embodiment, the integrated membrane electrode assembly is a five-in-one membrane electrode assembly that integrates a diaphragm 100, an electrode 300, and an elastic mesh 400. In other embodiments, the integrated membrane electrode assembly may also integrate the elastic mesh 400 on only one side of the electrode 300, or integrate the electrode 300 and the elastic mesh 400 on only one side of the diaphragm 100, etc., all of which can achieve the effect of this embodiment.

[0081] In the above embodiments, the integrated membrane electrode assembly integrates a diaphragm 100, an electrode 300, and an elastic mesh 400. In another embodiment, the integrated membrane electrode assembly may further integrate a gasket. Please refer to [link to relevant documentation]. Figure 8 , Figure 8 This is a cross-sectional structural schematic diagram of another embodiment of the integrated membrane electrode assembly of this application.

[0082] like Figure 8 As shown, in this embodiment, the integrated membrane electrode assembly also includes a sealing gasket 600 on the side of the elastic mesh 400 facing away from the diaphragm 100. The sealing gasket 600 has a hollowed-out center, and the inner edge area of ​​the sealing gasket 600 is fixedly connected to the elastic mesh 400, thereby forming a six-in-one integrated membrane electrode assembly.

[0083] In this embodiment, the elastic mesh 400 and the sealing gasket 600 are glued together. The integrated membrane electrode assembly also includes a first adhesive layer 700 and a second adhesive layer 800. The first adhesive layer 700 is disposed on the side of the sealing gasket 600 facing the elastic mesh 400, and the second adhesive layer 800 is disposed on the side of the elastic mesh 400 facing the sealing gasket 600. The first adhesive layer 700 and the second adhesive layer 800 cooperate to fix the sealing gasket 600 and the elastic mesh 400.

[0084] In the electrolytic cell, the sealing gasket 600 plays a role in sealing and insulation. To ensure sealing and insulation performance, the sealing gasket 600 is generally made of modified polytetrafluoroethylene material filled with carbon fiber, molybdenum disulfide and other reinforcing fillers. This material is difficult to directly bond and fix with the metal elastic mesh 400.

[0085] In order to achieve integration of the sealing gasket 600 with other components, this embodiment uses two adhesive layers to bond and fix the sealing gasket 600 and the elastic mesh 400. Specifically, the first adhesive layer 700 can be a soluble polytetrafluoroethylene resin layer, and the second adhesive layer 800 can be a polyphenylene sulfone layer, a polysulfone layer, a polyethersulfone layer, or a polyphenylene sulfide layer.

[0086] The thicknesses of the first adhesive layer 700 and the second adhesive layer 800 can be adjusted based on actual needs, ensuring bonding strength while avoiding excessive component thickness that could affect assembly. For example, the thicknesses of the first adhesive layer 700 and the second adhesive layer 800 can be 0.5–0.8 mm.

[0087] In order to avoid affecting the electrolysis performance, in this embodiment, the inner edge of the sealing gasket 600 is arranged to overlap with the orthographic projection of the inner edge of the first plastic layer 200.

[0088] In order to further improve the fixing stability of the sealing gasket 600 and other components, and at the same time ensure the concentricity of each component, in this embodiment, an annular groove 601 is arranged on the inner edge of one side of the sealing gasket 600, and the elastic mesh 400 is embedded in the annular groove 601.

[0089] In this embodiment, the sealing gasket 600 is glued to the elastic net 400. In other embodiments, the sealing gasket 600 can also be fixed to the elastic net 400 in other ways. For example, a fastener can be provided on the sealing gasket 600, and the sealing gasket can be fixed to the elastic net 400 through the fastener. All of these methods can achieve the effect of this embodiment.

[0090] It should be noted that the integrated membrane electrode assembly of this embodiment is applied in an electrolytic cell chamber with a single gasket. In other application scenarios, when it is necessary to arrange double gaskets in a single chamber, sealing gaskets 600 can also be provided on the back of the elastic mesh 400 on both sides of the diaphragm 100 in this embodiment, thereby realizing a seven-in-one membrane electrode assembly, which can also achieve the effect of this embodiment.

[0091] The integrated membrane electrode assembly based on the above embodiments realizes the integrated setting of multiple components, which can effectively reduce assembly processes and difficulties, help improve the high precision and consistency of assembly, and thus help improve the overall efficiency and product quality of the electrolyzer, and reduce assembly costs.

[0092] This application also provides a method for fabricating the integrated membrane electrode assembly of the above embodiments. Please refer to [link to relevant documentation]. Figure 9 , Figure 9 This is a schematic flowchart illustrating one embodiment of the preparation method of the integrated membrane electrode assembly of this application.

[0093] like Figure 9 The preparation method includes:

[0094] S100. Add the plastic solute to the solvent, heat and stir to dissolve the plastic solute, and obtain the plastic adhesive.

[0095] First, plastic adhesives are obtained by dissolving plastic solutes in a solvent.

[0096] In one embodiment, the mass fraction of plastic solute in the plastic adhesive can be 5% to 50%.

[0097] In one embodiment, the plastic solute may be polyphenylene sulfone resin, polysulfone or polyethersulfone, and the solvent may be N-methylpyrrolidone, dimethylformamide, dimethylacetamide or dimethyl sulfoxide.

[0098] More specifically, when the plastic solute is polyphenylsulfone resin and the solvent is N-methylpyrrolidone, the solvent can be heated to 120-150°C and then stirred for 5-20 hours to ensure the complete dissolution of the plastic solute.

[0099] In other embodiments, when other plastic solutes and solvents are used, the heating temperature and stirring time can be adjusted based on the actual working conditions to ensure that the plastic solute is fully dissolved in the solvent, thus achieving the effect of this embodiment.

[0100] S200. Apply plastic adhesive evenly to the outer edge of one side of the electrode or the outer edge of one side of the diaphragm. Then, attach the electrode and the diaphragm together with the plastic adhesive and clamp them in place. Then, let them stand, immerse them in water, and dry them in sequence to form the first plastic layer.

[0101] After applying a plastic adhesive and bonding the electrode and diaphragm together, the parts are first clamped and fixed and left to stand, allowing the plastic adhesive to wet the diaphragm. Then, the parts are immersed in water. During the immersion process, solvent-induced phase separation and polymer aggregation occur, which cures the plastic adhesive and ensures a strong bond between the electrode and the diaphragm. After drying at room temperature, an integrated membrane electrode assembly is obtained.

[0102] In one implementation, the settling time can be 3 to 30 minutes.

[0103] In one embodiment, the soaking time can be 2 to 12 hours.

[0104] The beneficial effects of the technical solution of this application will be further explained in detail below with reference to specific embodiments.

[0105] Example 1:

[0106] A five-in-one integrated membrane electrode assembly, with the structure as follows: Figure 5As shown, in this integrated membrane electrode assembly, the thickness of the first plastic layer 200 is 0.5 mm, the radial extension width of the fixing region 105 in the diaphragm 100 is 8 mm, and the radial extension width of the extension region 106 in the diaphragm 100 is 10 mm.

[0107] The fabrication method of this integrated membrane electrode assembly is as follows:

[0108] Add 20% by mass of polyphenyl sulfone resin to an N-methylpyrrolidone solution and stir at 130°C for 10 hours to obtain a plastic adhesive.

[0109] Apply plastic adhesive evenly to the anode and one outer edge of the anode to be assembled. Then attach the anode and cathode to the diaphragm, ensuring that the anode and cathode are completely opposite to each other. Press and clamp the diaphragm with a clamp and let it stand for 3 minutes to allow the adhesive to wet the diaphragm. Then immerse it in pure water for 2 hours. After taking it out, let it dry at room temperature to obtain a five-in-one integrated membrane electrode assembly.

[0110] Examples 2 to 9:

[0111] A five-in-one integrated membrane electrode assembly, with the same structure and preparation method as Example 1, differs from Example 1 in that:

[0112] The mass fraction of plastic solute, standing time, or soaking time in plastic adhesives can vary.

[0113] The fabrication process parameters of the integrated membrane electrode assembly in the above embodiments are shown in the table below.

[0114]

[0115]

[0116] Example 1: Bond Shear Strength Test

[0117] The adhesion shear strength between the electrode and the diaphragm in the membrane electrode assemblies of Examples 1 to 9 was tested using a tensile testing machine. The test method was in accordance with standard GB / T3923.1-2013. The experimental results are shown in the table below.

[0118]

[0119] As shown in the data above, in the membrane electrode assemblies of Examples 1 to 9, the electrodes and the diaphragms have a large bond shear strength, which can effectively prevent misalignment of the electrodes and diaphragms during transportation and assembly, and help improve the assembly consistency and accuracy of each component in the electrolytic cell.

[0120] Example 2:

[0121] The integrated membrane electrode assembly of Example 1 was selected and loaded into an electrolytic cell for stacking test. At the same time, a split membrane electrode was loaded into the same electrolytic cell for stacking test. The membrane, electrode and elastic mesh used in the split membrane electrode were exactly the same as those used in the integrated membrane electrode assembly of Example 1.

[0122] Specifically, the stacking test was conducted at 30% KOH and 80℃ for 94 hours, with the cell voltage recorded every hour. Figure 10 , Figure 10 This is a graph showing the cell voltage data from the stacking test of Example 2 of this application.

[0123] like Figure 10 As shown, the cell operating voltage of the integrated membrane electrode assembly in Example 1 and the conventional split assembly were both stable during the test. The cell voltage of the integrated membrane electrode assembly was reduced by about 12mV compared with the conventional split assembly. This is mainly because the integrated membrane electrode assembly has higher assembly precision, which is more conducive to the catalytic reaction.

[0124] Example of effect 3:

[0125] To investigate the effect of the first plastic layer on the surface resistance of the diaphragm during the operation of the electrolyzer, two integrated membrane electrode assemblies from Example 1 were selected as samples. The surface resistance of the diaphragm before the stacking test and the surface resistance of the edge and middle of the diaphragm after the stacking test of Example 2 were tested. The test method was in accordance with standard SJ / T10171.5-1991. The results are shown in the table below.

[0126]

[0127] As shown in the table above, the surface resistance of the diaphragm after the stacking test did not increase compared to before operation, indicating that the first plastic layer will not have an adverse effect on the diaphragm during the operation of the electrolyzer and will not introduce additional resistance.

[0128] Example of effect 4:

[0129] To investigate the effect of the integrated membrane electrode assembly on gas purity, the applicant tested the purity of the gas prepared by the integrated membrane electrode assembly of Example 1 and the split membrane electrode assembly of Example 2 in the stacking test, and obtained the data in the table below.

[0130]

[0131]

[0132] As shown in the table above, the gas purity prepared by the integrated membrane electrode assembly in Example 1 is significantly better than that of the traditional split membrane electrode assembly. This is because the integrated membrane electrode assembly significantly improves the assembly accuracy, enhances the sealing performance at the edges, and prevents gas cross-contamination.

[0133] It will be apparent to those skilled in the art that this application is not limited to the details of the exemplary embodiments described above, and that this application can be implemented in other specific forms without departing from the spirit or essential characteristics of this application. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this application is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this application. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0134] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An integrated membrane electrode assembly, characterized in that, include: A diaphragm includes a first surface and a second surface disposed opposite to each other, and an electrolyte channel is arranged on the diaphragm to connect the first surface and the second surface. The diaphragm includes an electrolyte channel region located in the middle and a fixed region surrounding the electrolyte channel region. Electrodes are disposed on the first surface and / or the second surface, the electrodes covering the fixed area; A first plastic layer is disposed within the electrolyte channel of the fixed area, and the first plastic layer extends to the first surface and / or the second surface to fix the diaphragm and the electrode.

2. The integrated membrane electrode assembly according to claim 1, characterized in that, The electrode includes a cathode and an anode disposed on the first surface and the second surface, respectively, and the first plastic layer extends to the first surface and the second surface.

3. The integrated membrane electrode assembly according to claim 1, characterized in that, The first plastic layer is a polyphenylene sulfone resin layer, a polysulfone layer, or a polyethersulfone layer; and / or, The first plastic layer extends to a depth of 0.5–0.8 mm within the electrolyte channel; and / or, The fixing region extends radially across the diaphragm with a width of 5–20 mm; and / or, The diaphragm also includes an extension region surrounding the fixed region, the extension region having a radial width of 7 to 15 mm in the diaphragm.

4. The integrated membrane electrode assembly according to claim 1, characterized in that, The outer edge of the electrode overlaps with the orthographic projection of the outer edge of the fixed area.

5. The integrated membrane electrode assembly according to claim 1, characterized in that, It also includes an elastic mesh disposed on the side of the electrode opposite to the diaphragm, the outer edge region of the elastic mesh being fixed to the electrode.

6. The integrated membrane electrode assembly according to claim 5, characterized in that, The elastic mesh includes a welding area arranged on its outer edge, which is welded and fixed in close contact with the electrode, and the orthographic projection of the welding area overlaps with that of the fixing area.

7. The integrated membrane electrode assembly according to claim 5, characterized in that, The elastic mesh includes an adhesive region disposed on its outer edge, and the integrated membrane electrode assembly further includes a second plastic layer disposed between the adhesive region and the electrode, the second plastic layer being a polyphenylene sulfone resin layer, a polysulfone layer, or a polyethersulfone layer.

8. The integrated membrane electrode assembly according to claim 5, characterized in that, It also includes a sealing gasket disposed on the side of the elastic mesh opposite to the diaphragm, the sealing gasket having a hollowed-out center and the inner edge region of the sealing gasket being fixed to the elastic mesh.

9. The integrated membrane electrode assembly according to claim 8, characterized in that, The inner edge of the sealing gasket overlaps with the orthographic projection of the inner edge of the fixing area; and / or, The sealing gasket has an annular groove on one inner edge, and the elastic mesh is embedded in the annular groove.

10. The integrated membrane electrode assembly according to claim 8, characterized in that, It also includes a first adhesive layer and a second adhesive layer. The first adhesive layer is disposed on the side of the sealing gasket facing the elastic mesh, and the second adhesive layer is disposed on the side of the elastic mesh facing the sealing gasket. The first adhesive layer and the second adhesive layer cooperate to fix the sealing gasket and the elastic mesh. The first adhesive layer is a soluble polytetrafluoroethylene resin layer, and the second adhesive layer is a polyphenylene sulfone layer, a polysulfone layer, a polyethersulfone layer, or a polyphenylene sulfide layer; and / or, The integrated membrane electrode assembly also includes a snap-fit ​​component for securing the sealing gasket and the elastic mesh.

11. An alkaline electrolytic cell, characterized in that, It includes a tank and several integrated membrane electrode assemblies as described in any one of claims 1 to 10, wherein the integrated membrane electrode assemblies are arranged in a stacked manner within the tank.

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