An AEM electrolytic cell

Abstract

The application relates to an AEM electrolytic cell which improves the current density and heat exchange capacity of the electrolytic cell. Liquid on the anode side of each single section of the electrolytic cell can uniformly and quickly reach the surface of a cathode, oxygen generated on the anode side can be quickly and effectively discharged from the electrolytic cell, hydrogen generated on the cathode side and water permeated from the cathode can be timely and efficiently discharged from the electrolytic cell, and certain pressure is provided for a cathode catalytic layer and an anode catalytic layer so that the catalytic layers are uniformly attached to the two sides of the cathode. 2 In a comparison test of electrolysis with an active area of 300 cm2, under the condition of a voltage of 2 V and a temperature of 60 DEG C, the current value of the electrolytic cell with a flow field cut on a metal plate is 218 A, and the current value of the electrolytic cell with a grooved flow channel sponge-shaped foam metal flow field is 289 A, and the improvement efficiency is 32.56%. In other working conditions, the test current is also improved by 20%-32%.

Description

Technical Field

[0001] This invention relates to a method for optimizing and improving the uniformity of the liquid and gas flow field inside an AEM electrolyzer, thereby increasing the current density and heat exchange capacity of the electrolyzer. This method aims to ensure that the liquid on the anode side of each section of the electrolyzer flows uniformly and rapidly to the surface of the anion exchange membrane; that the oxygen generated on the anode side is quickly and effectively discharged from the electrolyzer; and that the hydrogen generated on the cathode side and the water permeating from the anion exchange membrane are discharged from the electrolyzer in a timely and efficient manner. Furthermore, it provides a certain pressure to the cathode and anode catalyst layers to ensure that the catalyst layers are uniformly adhered to both sides of the anion exchange membrane. Background Technology

[0002] Anion exchange membrane (AEM) water electrolysis is one of the most promising water electrolysis systems currently available, possessing significant market competitiveness. Compared to traditional alkaline water electrolysis, AEM electrolyzers can achieve low ohmic resistance and high gas purity; compared to proton exchange membrane (PEM) water electrolysis, AEM electrolyzers allow the use of highly active transition metal materials as electrochemical catalysts and substrates, resulting in lower overall costs.

[0003] However, a serious problem has been discovered in current industrial practice: as the active area of ​​a single electrode increases, the alkaline solution used as a raw material becomes unevenly distributed within the electrode. This unevenness prevents the catalyst in certain areas from fully participating in the reaction process, thus affecting the current density. Furthermore, the alkaline liquid flowing into the tank carries away the heat generated by the electrolysis of water in areas not involved in the reaction, requiring secondary temperature regulation to maintain a balanced temperature within the tank. In extreme cases, if the flow rate of the alkaline solution is not precisely controlled, it can lead to localized overheating, triggering a burnout of the electrolyzer.

[0004] Therefore, this invention aims to ensure the uniformity of the flow field by optimizing the electrode structure and improving the flow pattern of the alkaline water, thereby avoiding the risk of electrolyzer damage caused by localized overheating or other adverse conditions. By precisely controlling the flow rate and velocity of the alkaline water, heat loss can be effectively reduced and the temperature of the electrode surface can be kept stable, ultimately improving the performance and efficiency of the electrolyzer. This significantly improves the poor uniformity of liquid and gas distribution within the cell, reduces production costs, increases the hydrogen production efficiency of the electrolyzer, and simultaneously enhances the reliability and economy of the entire electrolyzer system. Summary of the Invention

[0005] This invention relates to a method for optimizing and improving the uniformity of liquid and gas flow fields inside an AEM electrolyzer, and the technical solution adopted is as follows:

[0006] An AEM electrolytic cell can be a single-section AEM electrolytic cell or multiple AEM electrolytic cells stacked sequentially.

[0007] A single-section AEM electrolytic cell has electrodes at both ends, with a set of hollow annular cathode electrode frames, anion exchange membranes, and hollow annular anode electrode frames stacked sequentially between the two electrodes. A multi-section AEM electrolytic cell has electrodes at both ends, with multiple sets of hollow annular cathode electrode frames, anion exchange membranes, and hollow annular anode electrode frames stacked sequentially between the two electrodes, with adjacent sets separated by bipolar plates. The hollow cavity in the middle of the hollow annular cathode electrode frame contains the cathode, and the hollow cavity in the middle of the hollow annular anode electrode frame contains the anode.

[0008] A flat sheet of foam metal is placed in the central cavity of the hollow annular cathode electrode frame. The flat sheet of foam metal is located between the cathode and the electrode plate or between the cathode and the bipolar plate. After being assembled into an AEM electrolytic cell, one side of the flat sheet of foam metal is attached to the cathode and the other side is attached to the electrode plate or bipolar plate.

[0009] A flat sheet of foam metal is placed in the central cavity of the hollow annular anode electrode frame. The flat sheet of foam metal is located between the anode and the electrode plate or between the anode and the bipolar plate. After being assembled into an AEM electrolytic cell, one side of the flat sheet of foam metal is attached to the anode and the other side is attached to the electrode plate or bipolar plate.

[0010] The cathode cavity is formed by the electrode plate or bipolar plate on one side of the hollow annular cathode electrode frame, the anion exchange membrane on the other side, and the central chamber surrounded by the hollow annular cathode electrode frame. The area inside the cathode cavity, except for the cathode, is filled with sponge-like foam metal material.

[0011] The anode cavity is formed by the electrode plate or bipolar plate on one side of the hollow annular anode electrode frame, the anion exchange membrane on the other side, and the central chamber surrounded by the hollow annular anode electrode frame. The area inside the anode cavity, except for the cathode, is filled with sponge-like foam metal material.

[0012] The porosity of the sponge-like foam metal material is 72-96%.

[0013] A flow field formed by grooved channels is provided on the surface of the flat foam metal near the electrode plate or bipolar plate; the flow field on the surface of the sponge-like foam metal sheet in the cathode electrode frame is the cathode flow field, and the flow field on the surface of the sponge-like foam metal sheet in the anode electrode frame is the anode flow field.

[0014] The foamed metal material has a flat plate structure. In order to improve the flow of liquid on the anode side and the uniformity of liquid water distribution, grooved flow channels are added on the side of the sponge-like foamed metal material away from the electrode (cathode or anode) to form a flow field. In this way, the flow channel of the sponge-like foamed metal material forms a spatial network flow channel structure with the grooved flow channel as the main flow channel and the three-dimensional microporous channel as the branch flow channel.

[0015] The foam metal is one or more of the following: foamed nickel, foamed titanium, and foamed iron;

[0016] The groove is 1mm to 5mm wide and the groove depth is 20% to 85% of the thickness of the sponge-like foam metal material;

[0017] Groove flow channels refer to grooves on sponge-like foam metal, whose cross-sectional shape perpendicular to the fluid flow direction includes, but is limited to, one or more of other irregular shapes such as rectangle, trapezoid, semicircle, and ellipse;

[0018] The axial shape of the flow channel along the direction of fluid flow includes, but is not limited to, one or more of the following curve shapes: straight line, broken line, S-curve, circle, sine, normal distribution, etc.

[0019] The grooved flow channel is located on the side of the sponge-like foam metal near the electrode plate or bipolar plate;

[0020] Flow channel distribution: In a sponge-like foam metal flow field, including but not limited to one or more of the following: overall distribution, partial distribution, uniform distribution, and non-uniform distribution;

[0021] The flow channel includes, but is not limited to, having one or more of the following: intersection, merging, branching, or point-like isolation points;

[0022] The flow channel includes, but is not limited to, a single or multiple channels, preferably two or more parallel flow channels.

[0023] The surface of the electrode plate near the foam metal or the two surfaces of the bipolar plate are flat plate structures, that is, there is no flow field on them and they are smooth planes.

[0024] A cathode distribution channel is provided on the upper and / or lower side of one side surface of the annular cathode electrode frame near the electrode plate or bipolar plate. One or both ends of the channel are connected to the cathode port (outlet) of the cathode flow field and the cathode gas-liquid outlet channel of the AEM electrolysis cell, respectively. There is one or two cathode ports, which are mainly used for hydrogen gas output and liquid drainage (outlet). They also have nitrogen purging functions (one inlet and one outlet when there are two ports).

[0025] On the upper and lower sides of one side surface of the annular anode electrode frame near the electrode plate or bipolar plate, there are anode distribution channels, with their two ends connected to the inlet and outlet ends of the anode flow field and the anode inlet and outlet channels of the AEM electrolytic cell, respectively; one side of the anode distribution channel is connected to the inlet end of the anode flow field and the anode inlet channel of the AEM electrolytic cell, respectively, and the other side of the anode distribution channel is connected to the outlet end of the anode flow field and the anode outlet channel of the AEM electrolytic cell, respectively.

[0026] The cathode includes a cathode catalytic layer, or a cathode catalytic substrate and a cathode catalytic layer. The cathode catalytic layer is attached to or coated on one side surface of the cathode catalytic substrate or the cathode side of the anion exchange membrane, and the cathode catalytic layer is disposed facing the anion exchange membrane side.

[0027] The anode includes an anode catalyst layer, or includes an anode catalyst substrate and an anode catalyst layer. The anode catalyst layer is attached to or coated on one side surface of the anode catalyst substrate or the anode side of the cation exchange membrane, and the anode catalyst layer is facing and attached to the anion exchange membrane. The opposite side of the anode catalyst substrate is facing and attached to the foam metal (as a diffusion layer of the electrode).

[0028] The cathode catalytic substrate and the anode catalytic substrate are both sheet-like structures with micropores, and can be one or more of the following: mesh carbon paper, carbon cloth, metal wire mesh, and metal felt.

[0029] The anode and cathode flow fields of the electrolyzer are constructed using sponge-like foamed metal materials. Each section of the electrolyzer is divided into two parts by an anion exchange membrane: a cathode chamber and an anode chamber. Both chambers, except for the use of a mesh support with a catalyst layer, are filled with a flow field of sponge-like foamed metal material. The three-dimensional mesh channel of the sponge-like foamed metal material flow field in the anode chamber ensures that water entering the anode chamber from the anode port near the electrode or bipolar plate surface is evenly distributed to the anode-side surface of the anion exchange membrane. It also provides a three-dimensional channel for the oxygen generated and excess water produced in the anode chamber to be discharged from the anode port near the electrode or bipolar plate surface on the other side. The three-dimensional mesh structure of the sponge-like foamed metal material flow field in the cathode chamber allows hydrogen generated on the cathode side of the anion exchange membrane and a small amount of water permeating from the membrane to be discharged from the cathode port of the electrolyzer.

[0030] The flow field of sponge-like foamed metal materials is generally a flat plate structure. To improve the flow and uniform distribution of liquid on the anode side, this invention adds grooved channels on the side of the flat sponge-like foamed metal material facing away from the catalyst layer. This creates a spatial network flow channel structure with grooved channels as the main flow channels and three-dimensional microporous channels as branch channels. Liquid entering from the anode port in the anode cavity can be quickly distributed throughout the anode flow field through the grooved channels. Simultaneously, through the three-dimensional microporous channels of the anode flow field, the liquid is further distributed, reaching the anode catalyst layer more evenly. Oxygen generated in the anode catalyst layer can enter the grooved channels of the anode flow field through the three-dimensional micropores, and then drain to the anode port and outside the electrolytic cell with minimal flow resistance. Hydrogen generated on the cathode side and leaking liquid also enter the grooved channels of the cathode flow field through the three-dimensional microporous channels, draining to the cathode port with minimal flow resistance. After testing the porosity of different sponge-like foamed metal materials, a porosity of 72-96% was found to be optimal. The tank width is 1mm to 5mm, and the tank depth is 20% to 85% of the thickness of the sponge-like foam metal material. Actual tests of the electrolytic cell show that adding a tank-shaped flow channel can increase the current density by 20% to 32.6%.

[0031] As a sponge-like foamed metal material, it has grooved channels on its surface. Liquids and gases within these channels flow through them, rapidly distributing to various regions of the diffusion layer. Simultaneously, they permeate through the micropores of the sponge-like foamed metal material, interacting with the anion exchange membrane.

[0032] Meanwhile, the sponge-like foam metal material flow field plays a supporting role within the section, enabling the cathode and anode catalyst layers to adhere tightly to the anion exchange membrane under different operating conditions. This helps the anions generated on the anode catalyst layer to be efficiently transported through the anion exchange membrane to the surface of the cathode catalyst layer, thus efficiently generating oxygen.

[0033] By relying on the assembly force of the fuel cell stack, the flow channel and the electrode plate form a complete flow channel wall, which can effectively ensure the flow of gas and liquid within the flow channel.

[0034] The flow channel refers to the groove on the sponge-like foam metal material, and its cross-sectional shape includes, but is limited to, rectangular, circular, trapezoidal, semi-circular, elliptical and other irregular shapes.

[0035] The longitudinal shape of the flow channel includes, but is not limited to, straight lines, broken lines, S-curves, circles, sine waves, normal distributions, and other curved shapes.

[0036] Flow channel distribution: On the diffusion layer of the sponge-like foam metal material, including but not limited to overall distribution, partial distribution, uniform distribution, and non-uniform distribution.

[0037] Flow channels include, but are not limited to, those with intersections, mergers, branches, or point-like isolation points.

[0038] The flow channel includes, but is not limited to, single channels, multiple channels, and combinations thereof.

[0039] In this manner, no flow channels need to be fabricated on the electrode plates. The grooved flow channels of the sponge-like foam metal flow field form a complete flow channel with the electrode plates through the screw locking force of the outer end plate of the fuel cell stack. Because the grooved flow channels are located on the side of the sponge-like foam metal flow field, rather than being opened on the electrode plates, this structure shortens the liquid and gas transport distance and reduces the flow resistance of gas and liquid within the flow channels. The screw locking force of the outer end plate locks the cathode frame, anode frame, anion exchange membrane, and electrode plates together, forming the cathode cavity and anode cavity respectively. Each cavity contains a sheet-like catalyst substrate with a catalytic layer and a sponge-like foam metal flow field. After assembly, the flow channel surface of the sponge-like foam metal flow field is tightly attached to the electrode plates; the channelless surface of the diffusion layer is attached to the non-catalytic layer of the catalyst support; and the catalytic layer of the catalyst substrate is tightly attached to the anion exchange membrane.

[0040] Sponge-like foamed metal, with its rich three-dimensional channel structure, possesses excellent capabilities for transporting liquids and gases. Compared to conventional flow fields created by cutting or stamping on metal electrodes, using a sponge-like foamed metal flow field with grooved channels significantly improves hydrogen production efficiency and reduces processing costs. Adding grooved channels to the side of the sponge-like foamed metal away from the anion exchange membrane further improves the uniformity of liquid and gas distribution within the tank. A comparative test was conducted on a specific electrolyzer. The comparative test used a sponge-like foamed metal flow field with flow channels and an electrolyzer with bipolar plates created by metal cutting; all other components were identical except for the aforementioned differences. The test conditions were the same: a DC voltage of 1.6–2V, a temperature of 60℃, and a water flow rate of 10L / min. At 2V, the current density of the electrolyzer with a flow field created by cutting on the metal electrodes was 0.76A / cm². 2 The current value of the electrolytic cell with a flow field of sponge-like foamed metal with flow channels is 0.98 A / cm. 2 The efficiency was improved by 29%. The test current also increased by 22% to 30% under other operating conditions. Attached Figure Description

[0041] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0042] Figure 1 : A schematic diagram of the structure of the entire stack of multiple single sections in this invention (the first electrode plate on the left has been removed).

[0043] Figure 2 : Schematic diagram of a single electrolytic cell in this invention.

[0044] In the diagram: 1. Electrode plate; 2. Cathode electrode frame; 2.1. Cathode port (comprising features shared with 1-8); 3. Cathode catalytic substrate; 3.1. Cathode catalytic layer; 4. Anode catalytic substrate; 4.1. Cathode catalytic layer; 5. Anode electrode frame; 5.1. Anode port (comprising features shared with 1-8); 6. Anode flow field; 6.1. Anode flow field groove channel; 7. Anion exchange membrane; 8. Cathode flow field; 8.1. Cathode flow field groove channel; 9. Anode cavity (composed of the space enclosed by 5 / 1 / 7, with 4 / 6 placed within it); 10. Cathode cavity (composed of the space enclosed by 2 / 1 / 7, with 3 / 8 placed within it);

[0045] Figure 3 Comparison of test results for two flow field structures at 60℃, water flow rate of 10L / min, and voltage of 1.6V~2.0V. Detailed Implementation

[0046] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention. These all fall within the scope of protection of the present invention.

[0047] Example 1

[0048] See Figure 1 as well as Figure 2 As shown in the figure, the specific structure is as follows:

[0049] An AEM electrolytic cell, comprising 20 AEM electrolytic cells stacked sequentially.

[0050] An AEM electrolytic cell comprises a hollow annular cathode electrode frame, an anion exchange membrane, and a hollow annular anode electrode frame, which are sequentially stacked between bipolar plates (end plates) spaced apart by bipolar plates. The central cavity of the hollow annular cathode electrode frame contains the cathode, and the central cavity of the hollow annular anode electrode frame contains the anode.

[0051] A flat sheet of foam metal is placed in the central cavity of the hollow annular cathode electrode frame. The flat sheet of foam metal is located between the cathode and the electrode plate or bipolar plate. After being assembled into an AEM electrolytic cell, one side of the sheet of foam metal is attached to the cathode and the other side is attached to the electrode plate or bipolar plate.

[0052] A flat sheet of foam metal is placed in the central cavity of the hollow annular anode electrode frame. The flat sheet of foam metal is located between the anode and the electrode plate or bipolar plate. After being assembled into an AEM electrolytic cell, one side of the sheet of foam metal is attached to the anode and the other side is attached to the electrode plate or bipolar plate.

[0053] The cathode cavity is formed by the electrode plate or bipolar plate on one side of the electrode frame, the anion exchange membrane on the other side, and the central cavity of the hollow annular cathode electrode frame surrounded by the electrode frame. The area inside the cathode cavity, except for the cathode, is filled with sponge-like foam metal material.

[0054] The anode cavity is formed by the electrode plate or bipolar plate on one side of the electrode frame, the anion exchange membrane on the other side, and the central cavity of the hollow annular anode electrode frame surrounded by the electrode frame. The area inside the anode cavity, except for the cathode, is filled with sponge-like foam metal material.

[0055] The porosity of the sponge-like foam metal material is 85%.

[0056] The flow field is formed by grooved channels on the surface of the flat foam metal near the electrode plate or bipolar plate; the flow field on the surface of the sponge-like foam metal sheet in the cathode electrode frame is the cathode flow field, and the flow field on the surface of the sponge-like foam metal sheet in the anode electrode frame is the anode flow field.

[0057] The foamed metal material has a flat plate structure. In order to improve the flow of liquid on the anode side and the uniformity of liquid water distribution, some grooved flow channels are added on the side of the sponge-like foamed metal material away from the electrode (cathode or anode) to form a flow field. In this way, the flow channel of the sponge-like foamed metal material forms a spatial network flow channel structure with the grooved flow channel as the main flow channel and the three-dimensional microporous channel as the branch flow channel.

[0058] The groove is 3mm wide and its depth is 50% of the thickness of the sponge-like foam metal material;

[0059] Grooved channels refer to grooves on sponge-like foam metal. Their cross-sectional shape perpendicular to the fluid flow direction is rectangular, and the axial shape of the channel along the fluid flow direction is a straight line.

[0060] The grooved flow channel is located on the side of the sponge-like foam metal near the electrode plate or bipolar plate;

[0061] Flow channel distribution: uniformly distributed in a sponge-like foam metal flow field; two or more parallel flow fields.

[0062] The surface of the electrode plate near the foam metal or the two surfaces of the bipolar plate are flat plate structures, that is, there is no flow field on them and they are smooth planes.

[0063] A cathode distribution channel is provided on two opposite sides of one side of the annular cathode electrode frame near the electrode plate or bipolar plate. Its two ends are respectively connected to the cathode port (outlet) of the cathode flow field and the cathode gas-liquid outlet of the AEM electrolysis cell. There are two cathode ports, both of which are mainly used for hydrogen gas output and liquid drainage (outlet). They also have nitrogen purging functions (one purging gas enters and the other exits when there are two ports).

[0064] On one side of the annular anode electrode frame near the electrode plate or bipolar plate, there are two opposite sides of the anode distribution channel, with its two ends connected to the inlet and outlet ends of the anode flow field and the anode inlet and outlet channels of the AEM electrolytic cell, respectively; one side of the anode distribution channel is connected to the inlet end of the anode flow field and the anode inlet channel of the AEM electrolytic cell, respectively, and the other side of the anode distribution channel is connected to the outlet end of the anode flow field and the anode outlet channel of the AEM electrolytic cell, respectively.

[0065] Figure 1 It consists of 20 Figure 2 It is constructed by stacking individual sections. It is then secured with bolts through the outer end plate. The end plate has corresponding cathode and anode ports. Correspondingly, through holes serving as cathode and anode ports are also provided at the edges of the cathode electrode frame, anion exchange membrane, and anode electrode frame, forming the anode liquid inlet / outlet channel and the cathode gas / liquid outlet channel of the AEM electrolytic cell, allowing liquid to enter and exit the electrolytic cell and gas to exit the cell.

[0066] The foamed metal is foamed nickel;

[0067] The intermediate layer of each section is an anion exchange membrane (PHOENIX-30, Shanghai Hydrogen Technology Co., Ltd.) that selectively permeates anions. Both sides of the anion exchange membrane are coated or covered with cathode catalysts such as iron-based, nickel-based, and chromium-based catalysts (PHOENIX-Ca-5Ni / C, Shanghai Hydrogen Technology Co., Ltd.) and anode catalysts (PHOENIX-An-30Ni2P, Shanghai Hydrogen Technology Co., Ltd.). The side covered with the cathode catalyst is called the cathode, and the opposite side is called the anode. Channeled sponge-like metal foam is attached to the outside of each catalyst layer. An electrode frame surrounds the channeled sponge-like metal foam, and the anode electrode frame has channels. Liquid pumped into the electrolytic cell is distributed to the channels on the anode electrode frame of each section through the anode port, and then enters the anode cavity through the channels on the anode electrode frame. Inside the anode cavity, the channeled sponge-like metal foam evenly distributes the incoming liquid in the anode region and discharges excess liquid that has not participated in the electrolysis reaction and oxygen generated by the reaction through the channels on the other end of the anode electrode frame and the anode port. As anions permeate through the anion exchange membrane, hydrogen gas is generated on the cathode side. The hydrogen gas and the liquid that has permeated through the anion exchange membrane are discharged from the electrolytic cell through the cathode electrode frame channel and the cathode port via the flow channel of the sponge-like foam metal. Each section is separated by bipolar plates.

[0068] Specific operating parameters: current density for two flow field structures (Example 1 and Comparative Example) at 60℃ and a water flow rate of 10L / min under voltages of 1.6V to 2.0V (1.6V, 1.7V, 1.8V, 1.9V, and 2.0V respectively). Figure 3 As shown;

[0069] In Example 1 and the comparative example, the effective area of ​​each electrode in a single electrolytic cell is 100 cm².2 (10cm x 10cm)

[0070] Comparative electrolyzer structure: In this electrolyzer, neither the cathode nor anode cavity contains a sponge-like foam metal diffusion layer; both are hollow structures. The space is replaced by protrusions with flow channels at corresponding positions on the electrode / bipolar plate. The size and direction of the flow channels are the same as in Example 1. Diffusion primarily occurs through the flow channels of the electrode / bipolar plate. (This structure is similar to a common fuel cell bipolar plate structure.)

[0071] Example 2

[0072] See Figure 1 as well as Figure 2 As shown, the structure is the same as that of Example 1, except that the cathode or anode ports of Example 1, which are placed on opposite vertical sides of the square flow field in the electrolytic cell, are moved to the same side of the square flow field.

[0073] Example 3

[0074] See Figure 1 as well as Figure 2 As shown, the structure is the same as in Example 1, except that the square sponge-like foam metal flow field (flow channel, cross-sectional shape perpendicular to the fluid flow direction) in Example 1 is changed to a semi-circle.

Claims

1. An AEM electrolyzer comprising one or more than two AEM electrolyzers stacked in sequence, The single AEM electrolyzer comprises a polar plate, a hollow annular cathode electrode frame, an anion exchange membrane, a hollow annular anode electrode frame, and a polar plate stacked in sequence, and the more than two AEM electrolyzers comprise a hollow annular cathode electrode frame, an anion exchange membrane, and a hollow annular anode electrode frame spaced by bipolar plates between two polar plates; the hollow annular cathode electrode frame contains a cathode in the middle cavity, and the hollow annular anode electrode frame contains an anode in the middle cavity, characterized in that: A flat plate-shaped foam metal is arranged in the middle cavity of the hollow annular cathode electrode frame, and the flat plate-shaped foam metal is located between the cathode and the polar plate or the bipolar plate, and after the AEM electrolyzer is assembled, one side surface of the flat plate-shaped foam metal is attached to the cathode, and the other side surface is attached to the polar plate or the bipolar plate; A flat plate-shaped foam metal is arranged in the middle cavity of the hollow annular anode electrode frame, and the flat plate-shaped foam metal is located between the anode and the polar plate or the bipolar plate, and after the AEM electrolyzer is assembled, one side surface of the flat plate-shaped foam metal is attached to the anode, and the other side surface is attached to the polar plate or the bipolar plate.

2. The AEM electrolyzer according to claim 1, characterized in that: The cathode cavity is formed by the polar plate or the bipolar plate on one side of the electrode frame, the anion exchange membrane on the other side, and the middle cavity of the hollow annular cathode electrode frame surrounded by the electrode frame, and the area in the cathode cavity except the cathode is filled with sponge-shaped foam metal material; The anode cavity is formed by the polar plate or the bipolar plate on one side of the electrode frame, the anion exchange membrane on the other side, and the middle cavity of the hollow annular anode electrode frame surrounded by the electrode frame, and the area in the anode cavity except the cathode is filled with sponge-shaped foam metal material.

3. The AEM electrolyzer according to claim 2, characterized in that: The porosity of the sponge-shaped foam metal material is 72-96%.

4. The AEM electrolyzer according to claim 2, characterized in that: A flow field formed by a groove flow channel is provided on one side surface of the flat plate-shaped foam metal close to the polar plate or the bipolar plate; the flow field on one side surface of the sponge-shaped foam metal in the cathode electrode frame is a cathode flow field, and the flow field on one side surface of the sponge-shaped foam metal in the anode electrode frame is an anode flow field.

5. The AEM electrolyzer according to claim 4, characterized in that: The foam metal material is in a flat plate structure, and in order to better flow and uniformity of liquid water distribution on the anode side, some groove flow channels are added on the sponge-shaped foam metal material on the side away from the electrode in the flat plate structure to form a flow field; thus the flow channels of the sponge-shaped foam metal material form a space network flow channel structure with the groove flow channels as the main flow channels and the three-dimensional micropore channels as branch flow channels.

6. The AEM electrolyzer according to claim 4, characterized in that: The foam metal is one or more than two of foam nickel, foam titanium, and foam iron; The groove width is 1-5 mm, and the groove depth is 20-85% of the thickness of the sponge-shaped foam metal material. The groove flow channel refers to a groove on the sponge metal foam, the cross-sectional shape of which perpendicular to the fluid flow direction includes one or more than two of a rectangle, a trapezoid, a semicircle, and an ellipse; The axial shape of the flow channel along the fluid flow direction includes one or more than two of a straight line, a broken line, an S-shaped curve, a circle, a sine, and a normal distribution curve.

7. The AEM electrolytic cell according to claim 6, wherein: The groove flow channel is on the sponge metal foam close to the side of the polar plate or the bipolar plate; The flow channel distribution includes one or more than two of an overall distribution, a partial distribution, a uniform distribution, and a non-uniform distribution on the sponge metal foam flow field; The flow channel includes one or more than two of a cross, a merge, a branch, and a point-like isolation point in the middle; The flow channel includes a single or multiple roots.

8. The AEM electrolytic cell according to any one of claims 4-7, wherein: The surface of the polar plate close to the sponge metal or the surface of the bipolar plate on both sides is a flat plate structure, i.e., the surface is a smooth plane without a flow field; One side or the opposite side of the annular cathode electrode frame close to the polar plate or the bipolar plate is provided with a cathode distribution flow channel, one end or both ends of which are connected to the cathode port end of the cathode flow field and the cathode gas outlet liquid flow channel of the AEM electrolytic cell, respectively; the cathode port is one or two, which are mainly used for hydrogen gas outlet and liquid discharge, and also have a nitrogen gas blowing function; The opposite sides of the annular anode electrode frame close to the polar plate or the bipolar plate are respectively provided with an anode distribution flow channel, the two ends of which are respectively connected to the inlet and outlet ends of the anode flow field and the anode inlet and outlet liquid flow channels of the AEM electrolytic cell; the two ends of the anode distribution flow channel on one side are respectively connected to the inlet end of the anode flow field and the anode inlet liquid flow channel of the AEM electrolytic cell, and the two ends of the anode distribution flow channel on the other side are respectively connected to the outlet end of the anode flow field and the anode outlet liquid flow channel of the AEM electrolytic cell.

9. The AEM electrolytic cell according to claim 1, wherein: The cathode includes a cathode catalyst layer or a cathode catalyst substrate and a cathode catalyst layer, the cathode catalyst layer is attached or coated on one side surface of the cathode catalyst substrate or the cathode side of the anion exchange membrane, and the cathode catalyst layer faces the side of the anion exchange membrane; The anode includes an anode catalyst layer or an anode catalyst substrate and an anode catalyst layer, the anode catalyst layer is attached or coated on one side surface of the anode catalyst substrate or the anode side of the cation exchange membrane, and the anode catalyst layer faces and is attached to the anion exchange membrane, and the opposite surface of the anode catalyst substrate faces and is attached to the diffusion layer of the sponge metal as the electrode; The cathode catalyst substrate and the anode catalyst substrate are respectively in the form of a sheet with micropores, which can be one or more than two of a mesh carbon paper, a carbon cloth, a metal wire mesh, and a metal felt.

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