Alkaline electrolytic water hydrogen production device, electrolytic bath thereof and membrane electrode assembly of electrolytic bath

Abstract

The embodiment of the invention provides an alkaline water electrolysis hydrogen production device, an electrolytic bath thereof and a membrane electrode assembly of the electrolytic bath. The device is suitable for hydrogen production under the pressure difference environment of anode oxygen normal pressure and cathode hydrogen back pressure. The electrolytic bath comprises an anode end plate, an anode current collector, a membrane assembly, a cathode current collector and a cathode end plate. A water inlet is formed in the anode end plate and is used for injecting an electrolyte stock solution from one side of the anode side of the electrolytic cell. The membrane electrode assembly comprises an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer and a cathode diffusion layer, the exchange membrane comprises a first thin film and a second thin film which are in contact, the first thin film is an alkaline ionic membrane, and the second thin film is an ion solvation membrane or an anion exchange membrane. In operation, anode liquid supply and a differential pressure type scheme can be adopted for hydrogen production, and the problems that in an alkaline water electrolysis device adopting a traditional electrode, membrane puncture is caused during pressure operation, and hydrogen in oxygen exceeds the standard can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of alkaline water electrolysis hydrogen production, and in particular to an alkaline water electrolysis hydrogen production device, an electrolyzer thereof, and a membrane electrode assembly of the electrolyzer. Background Art

[0002] Among the existing water electrolysis technologies, alkaline (ALK) water electrolysis technology is the earliest discovered water electrolysis technology and is currently the most mature. Its principle is to apply direct current between two electrodes and use a diaphragm to separate the positive and negative poles. Hydroxyl ions in the electrolyte are reduced to generate hydrogen at the cathode and oxygen at the anode. However, ALK water electrolysis technology also has some limitations. First, ALK uses a polyphenylene sulfide diaphragm (PPS) with micropores as the diaphragm material. Its poor gas barrier properties can easily lead to mixing of hydrogen and oxygen, causing safety accidents. Therefore, the ALK water electrolysis hydrogen production system must be operated under equal pressure at the negative and positive poles through a pressure regulating valve, and cannot adapt to pressure fluctuations. Secondly, if Figure 1 As shown, the existing alkaline water electrolysis hydrogen production device includes an electrolyzer R, a cathode gas-liquid separator V1, an anode gas-liquid separator V0, a ​​hydrogen scrubber V2, an oxygen scrubber V3, a hydrogen condenser C1, and an oxygen condenser C2. The electrolyzer R is connected to the cathode gas-liquid separator V1 and the anode gas-liquid separator V0 respectively through a pump P. The hydrogen scrubber V2 is connected between the cathode gas-liquid separator V1 and the hydrogen condenser C1, and the outlet of the hydrogen condenser C1 is also connected to a hydrogen back-pressure valve PV02. The oxygen scrubber V3 is connected between the anode gas-liquid separator V0 and the oxygen condenser C2, and the outlet of the hydrogen condenser C1 is also connected to an oxygen back-pressure valve PV01. Therefore, in this existing alkaline water electrolysis hydrogen production device, the ALK electrolyzer must operate under the condition of double-sided liquid supply, which makes the water and gas management of the ALK particularly complicated, making the entire hydrogen production system complex and large. Finally, because ALK uses high-concentration alkaline solution as the electrolyte, it has a slow transmission speed problem, which makes it unable to adapt to power fluctuations.

[0003] At present, the industrialization of alkaline (ALK) water electrolysis technology still faces many challenges. First, the electrolysis efficiency of alkaline water electrolysis technology is low. Even if a diaphragm is used, the oxygen generated at the anode will still diffuse to the cathode and be reduced to water, which not only reduces the electrolysis efficiency but also poses a safety hazard. In addition, the current density of this technology is limited. The presence of liquid electrolytes and diaphragms makes it difficult for the electrolyzer to operate under high current density conditions, which limits its hydrogen production speed and efficiency. There are also difficulties in operating under high-pressure conditions, which is not conducive to large-scale industrial applications.

[0004] Anion exchange membrane (AEM) is a polymer membrane containing alkaline active groups that is selectively permeable to anions. In the field of hydrogen production by water electrolysis, anion exchange membrane water electrolysis (AEMWE) technology combines the advantages of low-cost electrodes for traditional alkaline water electrolysis with the high current density and rapid response of proton membrane water electrolysis. It operates under weakly alkaline conditions and can use non-precious metal catalysts and inexpensive metal bipolar plates, reducing catalyst costs and energy consumption. Furthermore, AEMWE technology exhibits excellent dynamic response characteristics, enabling rapid start and stop to adapt to fluctuations in renewable energy. Furthermore, AEMWE can use pure water or low-concentration alkaline solutions as electrolytes, avoiding the problem of strong corrosion and making the entire water electrolysis device leak-free, compact, and easy to handle. Compared to traditional alkaline water electrolysis, anion exchange membrane water electrolysis can operate at lower voltages, improving the energy conversion efficiency of the electrolysis process. It is also more tolerant to impurities and has a wider range of applications.

[0005] Anion exchange membranes are selective membranes typically made of polymers with positively charged functional groups. Because they selectively transmit anions while isolating gases such as oxygen and hydrogen, anion exchange membranes are a common membrane used for water electrolysis under alkaline conditions. However, their limited stability and low mechanical strength are key factors hindering their large-scale application. In the anodic environment, the side chains of anion exchange membranes are easily oxidized and scission occurs. This scission reduces the membrane's conductivity and affects ion transport efficiency. Over time, the membrane may become thinner or even rupture, ultimately rendering the electrolyzer unusable. This not only increases equipment maintenance costs but also limits the large-scale commercial development of anion exchange membrane-based water electrolysis hydrogen production technology. Consequently, anion exchange membranes have a short lifespan when used alone, requiring protective mechanisms to isolate them from the anodic environment.

[0006] Ion solvation membranes (ISMs) have demonstrated many excellent properties in water electrolysis technology. First, ISMs have excellent ion conductivity and stability. For example, anisotropic polybenzimidazole ion solvation membranes (PBI-aNS) composed of oriented nanosheets exhibit excellent ion conductivity and stability in 6M KOH (the alkaline solution used in existing ALK). In addition, ion solvation membranes (ISMs) are inexpensive. Therefore, ion solvation membranes (ISMs) are considered to be an ideal alternative to traditional ALk membranes to supplement the problems of complex operation, low current density, and high safety risks in existing ALK electrolysis.

[0007] However, when the ion solvation membrane (ISM) is directly used to replace the traditional ALK diaphragm for electrolysis, the ion solvation membrane (ISM) is extremely easy to be cut and punctured due to the ALK electrode structure. Therefore, the ion solvation membrane (ISM) cannot be used directly alone in ALK electrolysis. Summary of the Invention

[0008] Various aspects of the present application provide an alkaline water electrolysis hydrogen production device, an electrolyzer thereof, and a membrane electrode assembly of the electrolyzer to solve one or more of the above-mentioned problems.

[0009] The present application provides an electrolyzer for an alkaline water electrolysis hydrogen production device, comprising: an anode end plate, an anode current collector, a cathode current collector, a cathode end plate, and a membrane electrode assembly disposed between the anode current collector and the cathode current collector. The anode end plate is provided with a water inlet and a water outlet, and the cathode end plate is provided with a drain outlet. The water inlet is used to inject electrolyte stock from the anode side of the electrolyzer. After the hydrogen production reaction is completed, the water outlet is used to allow oxygen-rich electrolyte to flow out, and the drain outlet is used to allow hydrogen-rich electrolyte to flow out. The membrane electrode assembly includes an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer, and a cathode diffusion layer arranged in sequence from the anode current collector to the cathode current collector. The exchange membrane includes a first and second contacting membranes, the first membrane being interposed between the anode catalyst layer and the second membrane, the first membrane being an alkaline ion membrane, and the second membrane being an ion solvation membrane or an anion exchange membrane.

[0010] In some embodiments of the present application, the alkaline ion membrane is a polyetheretherketone membrane, a polyphenylene sulfide membrane, a polytetrafluoroethylene resin-modified asbestos membrane, an asbestos membrane, or a polysulfone membrane. The ion solvation membrane is a dense membrane containing Lewis acid functional groups. The anion exchange membrane is a polyarylether anion exchange membrane, an anion exchange membrane without an aryl ether bond, or other membrane that selectively conducts anions.

[0011] The present application also provides a membrane electrode assembly for an electrolyzer according to any of the above embodiments, comprising: an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer, and a cathode diffusion layer arranged in sequence. The exchange membrane comprises a first membrane and a second membrane in contact, the first membrane being interposed between the anode catalyst layer and the second membrane, the first membrane being an alkaline ion membrane, and the second membrane being an ion solvation membrane or an anion exchange membrane.

[0012] The present application also provides an alkaline water electrolysis hydrogen production device, which supplies electrolyte from the anode side and produces hydrogen under a pressure difference environment of normal oxygen pressure at the anode and hydrogen back pressure at the cathode. The alkaline water electrolysis hydrogen production device includes a cathode gas-liquid separator, a hydrogen scrubber, an oxygen scrubber, a hydrogen condenser, an oxygen condenser, and an electrolyzer as described in any of the above embodiments. The electrolyzer is connected to the cathode gas-liquid separator, the oxygen scrubber is connected between the electrolyzer and the oxygen condenser, the hydrogen scrubber is connected between the cathode gas-liquid separator and the hydrogen condenser, and the outlet of the hydrogen condenser is connected to the hydrogen back pressure valve.

[0013] In an embodiment of the present application, the exchange membrane of the membrane electrode assembly includes a first film and a second film in contact with each other, wherein the first film is an alkaline ion membrane and the second film is an ion solvation membrane or an anion exchange membrane. In the electrolytic cell provided in the embodiment of the present application, due to the close bonding between the two films, only a very small gap exists under the action of swelling. The first film with a microporous structure has good structural strength, can provide support, and reduce the oxidation of the second film by alkali and high potential, while the second film has good alkaline stability, mechanical stability and electrochemical stability, so that the exchange membrane of this double-layer membrane structure can be operated in a pressure difference environment, eliminating the risk of membrane puncture and avoiding the problem of excessive hydrogen in oxygen. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0015] Figure 1 It is a plan view of an existing alkaline water electrolysis hydrogen production device.

[0016] Figure 2 Schematic diagram of a plan view of an alkaline water electrolysis hydrogen production device according to an embodiment of the present application.

[0017] Figure 3 This is a schematic plan view of an electrolytic cell according to an embodiment of the present application.

[0018] Figure 4 for Figure 3 A simplified structural diagram of .

[0019] Figure 5 This is the electrochemical performance diagram of the first embodiment of this application.

[0020] Figure 6 This is the electrochemical performance diagram of the second embodiment of this application.

[0021] Figure 7 This is a diagram of the hydrogen content in oxygen according to an embodiment of the present application.

[0022] Figure 8 This is the electrochemical performance diagram of the third embodiment of the present application.

[0023] Figure 9 This is a graph of hydrogen content in oxygen according to the third embodiment of the present application. DETAILED DESCRIPTION

[0024] To make the purpose, technical solutions, and advantages of this application more clear, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and the corresponding drawings. Obviously, the embodiments described are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0025] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0026] See also Figures 2 to 4 The present application provides an alkaline water electrolysis hydrogen production device S, comprising an electrolyzer R1, a cathode gas-liquid separator V1, a hydrogen scrubber V2, an oxygen scrubber V3, a hydrogen condenser C1, and an oxygen condenser C2. The electrolyzer R is connected to the cathode gas-liquid separator V1, for example, via a pump P. The oxygen scrubber V3 is connected between the electrolyzer R and the oxygen condenser C2, and the hydrogen scrubber V2 is connected between the cathode gas-liquid separator V1 and the hydrogen condenser C1. The outlet of the hydrogen condenser C1 is connected to a hydrogen back-pressure valve PV.

[0027] The electrolytic cell R1 includes an anode end plate 110, an anode current collector 120, a cathode current collector 130, a cathode end plate 140, and a membrane electrode assembly 150, wherein the anode current collector 120, the cathode current collector 130, and the membrane electrode assembly 150 are sandwiched between the anode end plate 10 and the cathode end plate 140. A water inlet and a water outlet are provided on the anode end plate 110, and a water outlet is provided on the cathode end plate 140. The water inlet is used to inject electrolyte stock (e.g., 30% potassium hydroxide (KOH)) from the anode side of the electrolytic cell R1, the water outlet is used to allow the oxygen-rich electrolyte to flow out after the hydrogen production reaction is completed, and the water outlet is used to allow the hydrogen-rich electrolyte to flow out after the hydrogen production reaction is completed.

[0028] The membrane electrode assembly 150 is disposed between the anode current collector 120 and the cathode current collector 130, wherein the anode current collector 120 is located on one side of the anode end plate 110, and the cathode current collector 130 is located on one side of the cathode end plate 140. A bipolar plate 160 is disposed between two adjacent membrane electrode assemblies 150 among the multiple membrane electrode assemblies 150. In the electrolyzer R1 provided in the embodiment of the present application, the membrane electrode assembly 150 includes an anode diffusion layer 1510, an anode catalyst layer 1520, an exchange membrane 1530, a cathode catalyst layer 1540, and a cathode diffusion layer 1550, which are arranged in sequence from the anode current collector 120 toward the cathode current collector 130, such that the anode diffusion layer 1510 corresponds to the anode current collector 120, the cathode diffusion layer 1550 corresponds to the cathode current collector 130, and the exchange membrane 1530 is interposed between the anode catalyst layer 1520 and the cathode catalyst layer 1540.

[0029] The exchange membrane 1530 includes a first film 1531 and a second film 1532 in contact with each other. The first film 1531 is interposed between the anode catalyst layer 1520 and the second film 1532, such that the first film 1531 is located on the anode side and the second film 1532 is located on the cathode side. In this embodiment, the first film 1531 is an alkaline ion membrane, such as, but not limited to, a polyetheretherketone membrane (PEEK), a polyphenylene sulfide membrane (PPS), a polytetrafluoroethylene resin-modified asbestos membrane, an asbestos membrane, and a polysulfone membrane (PSF). The second film 1532 is an ion solvating membrane (ISM).

[0030] In an embodiment of the present application, the ion solvation membrane may be, but is not limited to, a dense membrane containing Lewis acid functional groups, which can solvate KOH and adsorb a large amount of electrolyte to form an ion transmission channel. Its composition is mainly based on polymers such as polybenzimidazole (PBI), and its ion conductivity is enhanced by introducing hydrophilic side chains (such as sulfonic acid groups) or compounding with other functional materials, so that the exchange membrane can provide a higher ion conductivity through the ion solvation membrane. And because the ion solvation membrane does not have ion exchange side chains, it avoids the degradation phenomenon of ionic groups or polymer main chain structures, and thus can also provide an exchange membrane with good alkali stability, mechanical stability and electrochemical stability. Its stability stems from the following reasons: First, the electrostatic force between ions and solvent molecules is the main source of stability of the solvation membrane. The electrostatic attraction between ions with high charge density and polar solvent molecules is stronger and can be tightly combined together; secondly, the physical properties of the solvent molecules themselves (such as polarity, dielectric constant) also have an important influence on stability. Polar solvents can better shield the electrostatic repulsion between ions, enhancing the stability of ion solvation membranes. Furthermore, the solvation membrane may further enhance stability through secondary forces such as hydrogen bonding. From a chemical perspective, the stability of the solvation membrane is closely related to the intrinsic properties of the ions (such as ionic radius and charge). Smaller ionic radius and higher charge make the electrostatic interactions between ions and solvent molecules more concentrated and intense. Therefore, the stability of ion solvation membranes is the result of the combined effects of the electrostatic interactions between ions and solvent molecules, the physical properties of the solvent molecules, and the intrinsic properties of the ions. This stability determines the ions' solubility behavior in solution, their ability to migrate, and their activity in chemical reactions.

[0031] The molecular structure of the ion solvation membrane used in some embodiments of the present invention is shown in the following structural formula 1:

[0032]

[0033] It should be noted that this molecular structure is only used as an example and is not limited to this in other embodiments of the present application.

[0034] In the molecular structure of this ion solvation membrane, the positive charge K + The groups are adsorbed and pass through the hydrophilic micropores or channels of the membrane under the electric field or concentration gradient, and then release OH - On the other side of the membrane, the functional groups are detached and enter the target solution or participate in the electrode reaction to generate O2.

[0035] Because ion-solvating membranes transfer hydroxide ions as cations ionically bonded to the polymer backbone, they are immune to chain breakage due to oxidation, unlike anion-exchange membranes. Anion-exchange membranes transfer hydroxide ions via side chains, which have relatively low molecular weights and are susceptible to oxidative degradation, leading to loss of conductivity and destabilization of the backbone, potentially damaging the anion-exchange membrane. Therefore, ion-solvating membranes exhibit excellent stability and are less susceptible to damage during electrolytic cell operation.

[0036] Generally speaking, the diaphragm used in the electrolyzer R1 is required to have gas barrier properties so that oxygen and hydrogen do not mix. Since ions are used as the medium for transporting electrons in the hydrogen production process, the existing alkaline water electrolysis hydrogen production device uses a diaphragm with a porous structure, which improves the electrolysis efficiency by virtue of its high ion permeability. However, the hydrogen and oxygen produced by the electrodes will adhere to the surface of this porous membrane in the form of bubbles, causing the pores on the surface of the porous membrane to be blocked, hindering the ions from transporting electrons, and thus easily causing the problem of increased voltage loss at the diaphragm. At the same time, this porous membrane cannot be operated under a pressure difference environment. Therefore, the exchange membrane 1530 of the electrolyzer R1 of the embodiment of the present application adopts a composite non-porous membrane, that is, an exchange membrane 1530 having both a first film 1531 and a second film 1532, wherein the microporous structure of the first film 1531 provides the support strength of the entire membrane and reduces the oxidation effect of the alkaline environment and high potential on the second film 1532 to increase the service life, while preventing the membrane 1532 from being cut or punctured by the electrode during pressure difference operation. The low gas permeability of the second film 1532 enables the exchange membrane 1530 to operate in a pressure differential environment. Therefore, the exchange membrane 1530 provided in this embodiment of the application can eliminate the risk of the exchange membrane 1532 being punctured during the hydrogen production process without affecting the electrochemical performance of the electrolyzer R1, while also solving the problem of excessive hydrogen in oxygen.

[0037] The following further illustrates the effects that can be achieved by the present application through the operation method and test results of the electrolytic cell R1 of the embodiment of the present application.

[0038] In the operating method of the electrolytic cell R1 provided in the exemplary embodiment of the present application, the exchange membrane 1530 comprises two sheets of equal-sized first and second films 1531 and 1532 arranged alternately. The exchange membrane 1530 provided in the first embodiment of the present application uses a 200 μm thick alkaline membrane as the first film 1531 and a 100 μm thick ion-solvation membrane as the second film 1532, which are bonded together by pressing or laminating. The exchange membrane 1530 provided in the second embodiment of the present application uses a 100 μm thick alkaline ion membrane as the first film 1531 and an 80 μm thick ion-solvation membrane as the second film 1532, which are bonded together by pressing or laminating. Therefore, the gap between the alkaline ion membrane and the ion-solvation membrane is very small and can be ignored. At the same time, an anode catalyst, such as NiFe, is coated on the surface between the first film 1531 and the anode diffusion layer 1510 to serve as the anode catalyst layer 1520, and a cathode catalyst, such as nickel-molybdenum alloy, is coated on the surface between the second film 1532 and the cathode diffusion layer 1550 to serve as the cathode catalyst layer 1540.

[0039] In the test, the alkaline water electrolysis hydrogen production device can supply electrolyte from the anode side and produce hydrogen under the pressure difference environment of normal oxygen pressure at the anode and hydrogen back pressure at the cathode. Specifically, when the embodiment of the present application adopts the anode liquid supply method to perform the water electrolysis performance test, 30% KOH solution can be used as the electrolyte, and hydrogen can be produced under the pressure difference environment of normal oxygen pressure at the anode and hydrogen back pressure (hydrogen pressure 1.6MPa) at the cathode. Figure 5 and Figure 6 As shown, from the relationship diagram between the measured current density and the electrolysis voltage, it can be seen that the electrolytic cell provided by either the first embodiment or the second embodiment of the present application has good electrochemical performance.

[0040] Based on the above, in the electrolyzer provided in the embodiment of the present application, the exchange membrane adopts a thinner first membrane and a thicker second membrane in combination, and adopts an anode liquid supply and a pressure difference scheme to produce hydrogen, that is, the anode oxygen is at normal pressure and the cathode hydrogen is at back pressure. The risk of membrane puncture during pressure difference operation when using traditional electrodes can be avoided. This can be seen from Figures 5 to 7 The test data of the electrolyzer provided in this application is verified. During the hydrogen production process, the exchange membrane can operate normally under a pressure difference environment, and the exchange membrane is not punctured to obtain the following Figures 5 to 7 of test data). Figure 7 At the same time, it is explained that the embodiment of the present application can also avoid the problem of excessive hydrogen in oxygen.

[0041] See also Figure 5 、 Figure 8 and Figure 9In the third embodiment of the present application, the first film 1531 of the exchange membrane 1530 is an alkaline ion membrane, and the second film 1532 is an anion exchange membrane, such as a polyarylether anion exchange membrane, an anion exchange membrane without an aromatic ether bond, or other membranes that can selectively conduct anions. Among them, the alkaline ion membrane with a microporous structure is mainly used to support the anion exchange membrane and reduce the oxidation of the anion exchange membrane by alkali and high potential. As a solid electrolyte, the anion exchange membrane has a higher OH - The transmission rate improves the power fluctuation adaptability of the exchange membrane 1530 and solves the problems of poor alkali resistance, poor oxidation resistance and low mechanical strength of general ion exchange membranes when used in traditional alkaline electrodes and devices.

[0042] In the test of electrochemical performance and hydrogen content in oxygen, the exchange membrane of the electrolytic cell provided in the third embodiment of the present application is a polyphenylene sulfide membrane in an alkaline membrane as the first membrane 1531, the second membrane 1532 is an anion exchange membrane, the anode is a 4625 type nickel mesh loaded with Raney nickel catalyst, the cathode is a 4625 type nickel mesh loaded with nickel-molybdenum alloy as the cathode, 30% potassium hydroxide is used for electrolysis at 80°C, and the electrolyte is only supplied to the anode, and the cathode hydrogen is subjected to a back pressure of 1MPa. The performance data obtained are as follows Figure 8 and Figure 9 shown.

[0043] from Figure 8 and Figure 9 It can be seen from the data that the electrochemical performance of the electrolytic cell provided by the third embodiment of the present application is similar to that of the first and second embodiments. In addition, like the first and second embodiments, it also has the beneficial effect of reducing the hydrogen concentration in oxygen on the anode side during the electrolysis process, thereby avoiding the hidden dangers caused by excessive hydrogen content in oxygen and improving operational safety.

[0044] Furthermore, the electrolyzer provided in the aforementioned embodiment of the present application utilizes a single-side water supply and single-side back pressure operation mode, which helps reduce device complexity and improve device safety. Furthermore, the assembly is compatible with the electrode structure of conventional alkaline water electrolysis devices, avoiding secondary development and reducing costs.

[0045] The foregoing is merely an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. An electrolyzer for an alkaline water electrolysis hydrogen production device, characterized in that: include: An anode end plate, an anode current collector, a cathode current collector, a cathode end plate, and a membrane electrode assembly disposed between the anode current collector and the cathode current collector, wherein the anode end plate is provided with a water inlet and a water outlet, and the cathode end plate is provided with a drain outlet, the water inlet is used to inject electrolyte stock from the anode side of the electrolyzer unilaterally, and when the hydrogen production reaction is completed, the water outlet is used to allow the oxygen-rich electrolyte to flow out, and the drain outlet is used to allow the hydrogen-rich electrolyte to flow out; The membrane electrode assembly includes an anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer and a cathode diffusion layer arranged in sequence from the anode current collector to the cathode current collector. The exchange membrane includes a first film and a second film in contact with each other, the first film is between the anode catalyst layer and the second film, and the first film is an alkaline ion membrane, and the second film is an ion solvation membrane or an anion exchange membrane.

2. The electrolytic cell according to claim 1, wherein The alkaline ion membrane is a polyetheretherketone membrane, a polyphenylene sulfide membrane, a polytetrafluoroethylene resin modified asbestos membrane, an asbestos membrane or a polysulfone membrane; the ion solvation membrane is a dense membrane containing Lewis acid functional groups; and the anion exchange membrane is a polyarylether anion exchange membrane, an anion exchange membrane without an aromatic ether bond or other membrane that can selectively conduct anions.

3. A membrane electrode assembly of an electrolytic cell according to claim 1 or 2, characterized in that: include: An anode diffusion layer, an anode catalyst layer, an exchange membrane, a cathode catalyst layer and a cathode diffusion layer arranged in sequence; The exchange membrane includes a first film and a second film in contact with each other, and the first film is between the anode catalyst layer and the second film. The first film is an alkaline ion membrane, and the second film is an ion solvation membrane or an anion exchange membrane.

4. The membrane electrode assembly according to claim 3, wherein: The alkaline ion membrane is a polyetheretherketone membrane, a polyphenylene sulfide membrane, a polytetrafluoroethylene resin modified asbestos membrane, an asbestos membrane or a polysulfone membrane; the ion solvation membrane is a dense membrane containing Lewis acid functional groups; and the anion exchange membrane is a polyarylether anion exchange membrane, an anion exchange membrane without an aromatic ether bond or other membrane that can selectively conduct anions.

5. An alkaline water electrolysis hydrogen production device, characterized in that, Hydrogen is produced under a pressure difference environment of normal oxygen pressure at the anode and hydrogen back pressure at the cathode. The alkaline water electrolysis hydrogen production device includes a cathode gas-liquid separator, a hydrogen scrubber, an oxygen scrubber, a hydrogen condenser, an oxygen condenser and an electrolyzer as described in claim 1 or 2, wherein the electrolyzer is connected to the cathode gas-liquid separator, the oxygen scrubber is connected between the electrolyzer and the oxygen condenser, the hydrogen scrubber is connected between the cathode gas-liquid separator and the hydrogen condenser, and the outlet of the hydrogen condenser is connected to the hydrogen back pressure valve.

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