PEM electrolytic bath and manufacturing method thereof

Abstract

The invention discloses a PEM electrolytic bath and a manufacturing method thereof. The PEM electrolytic bath comprises an end plate assembly, a first electrode and a second electrode, comprising a first end plate and a second end plate; the first end plate and / or the second end plate are / is provided with a water passing opening, a hydrogen opening and an oxygen water opening; a polar plate assembly; comprising N polar plates which are located between the first end plate and the second end plate. Water passing ports, hydrogen ports and oxygen water ports are formed in the positions, corresponding to the water passing ports, the hydrogen ports and the oxygen water ports of the end plate assemblies, of the N polar plates; a membrane electrode; comprising N-1 membrane electrodes which are arranged between two polar plates at intervals, the membrane electrodes and the polar plate assemblies form N-1 electrolysis chambers, and the N-1 electrolysis chambers at least comprise one hydrogen evolution reaction chamber and one oxygen evolution reaction chamber; a polar plate sealing structure; the polar plate sealing structures are arranged on N polar plates, and each polar plate is wrapped and sealed by adopting vulcanized rubber. Vulcanized rubber is adopted to seal the polar plate, parts are saved, meanwhile, the outer layer insulation function is achieved, and the cost is reduced on the basis that the performance requirement is met.

Description

Technical Field

[0001] The invention relates to a PEM electrolyzer and a manufacturing method thereof. Background Art

[0002] About 4% of the world's hydrogen comes from water electrolysis. The process is flexible, simple, pollution-free and has high product purity. Hydrogen production by water electrolysis is mainly used in industrial production that requires high purity and uses a small amount of hydrogen.

[0003] PEM electrolyzers have always played a leading role in hydrogen production systems. Existing products on the market are composed of stacked and pressed parts to form each positive and negative tank body. Its parts include end plates, filling layers, electrode plates, sealing gaskets, pole frames, interfaces and fasteners, etc. The tank body is formed by a stacking process, and then connected to a power source to electrolyze the water flowing through the flow field (support layer) in the tank body to form a hydrogen loop and an oxygen plus water circulation loop.

[0004] However, during the process of technical research and development, the inventors of this application found that the above technology has at least the following technical problems:

[0005] Due to the need for sealing, the electrolytic cells on the current market have increased the number and types of parts, including insulating plates, pole frames, gaskets, etc., which not only increases the complexity of the assembly and maintenance process, but also lacks great advantages in terms of economy. The electrolytic cell of this structure has obvious disadvantages: first, the pole plate, the sealing gasket and the sealing frame are independent components, the number of electrolytic cell components is large, the position control between each component is difficult, the production efficiency is low, the precision of the finished product is poor, and the sealing gasket and the pole plate need to be pressurized and sealed, there are many sealing gaps and long sealing lengths, and the gaps of the sealing gaskets are prone to electrolyte leakage; secondly, the edges of the pole plates are exposed, which is easy to cause external leakage or short circuit, and the uniformity of each electrolytic chamber is poor.

[0006] For example, Chinese invention patent CN109252185B "A process for manufacturing an electrolytic cell for an oxygen-hydrogen generator" can be used to manufacture large-scale industrial hydrogen production equipment. However, the patent mainly introduces a sulfidation process and adopts a flat-plate sealing structure, which can only seal a very small pressure (less than 1.0 MPa) and cannot reach the 2.0 MPa pressure set by the applicant.

[0007] For example, China's invention CN114032573A "A bipolar plate for a water electrolyzer" uses injection molding for non-metallic frame bipolar plates, which is metal insert injection molding, equivalent to injecting a plastic pole frame onto the pole plate. This structure integrates the pole plate + pole frame structure, and the mold cost is relatively high.

[0008] Therefore, the inventors of this application need to change the structure and reduce production costs while ensuring the normal operation of the electrolytic cell to enhance its market competitiveness. Summary of the invention

[0009] The purpose of the present invention is to solve the problems existing in the prior art and provide a PEM electrolyzer with low production cost and high cost performance and a manufacturing method thereof.

[0010] The technical solution for achieving the purpose of the present invention is a PEM electrolyzer, comprising:

[0011] The end plate assembly comprises a first end plate and a second end plate; the first end plate and / or the second end plate are provided with a water inlet, a hydrogen inlet and an oxygen water inlet;

[0012] A plate assembly; comprising N plates, the N plates being located between the first end plate and the second end plate; N being a natural number, greater than or equal to 2; the plate assembly comprising an anode terminal and a cathode terminal; a water inlet, a hydrogen inlet and an oxygen-water inlet are provided at positions of the N plates corresponding to the water inlet, the hydrogen inlet and the oxygen-water inlet of the end plate assembly;

[0013] Membrane electrode; comprising N-1 membrane electrodes, wherein the N-1 membrane electrodes are spaced between two of the electrode plates; the membrane electrode and the electrode plate assembly constitute N-1 electrolysis chambers, wherein the N-1 electrolysis chambers include at least one hydrogen evolution reaction chamber and one oxygen evolution reaction chamber;

[0014] A plate sealing structure is arranged on the N plates, and the plate sealing structure uses vulcanized rubber to wrap and seal each plate.

[0015] Furthermore, the PEM electrolyzer also includes:

[0016] Fixing assembly; the fixing assembly fixes the end plate assembly and the pole plate assembly together.

[0017] Furthermore, the N electrode plates are all provided with a sinking groove in the middle; the sinking grooves of adjacent electrode plates are arranged relative to each other to form a cavity serving as an electrolysis chamber.

[0018] Furthermore, the electrode plate sealing structure includes a rubber coating layer and a protrusion; the protrusion is arranged on the surface of the rubber coating layer at the connection between the sinking groove of the electrode plate and the electrode plate body, and is connected to the rubber coating layer as a whole.

[0019] Furthermore, the number of the protrusions is 2-4.

[0020] Furthermore, the PEM electrolyzer also includes:

[0021] A flow channel layer is arranged in the cavity of the electrolysis chamber; the flow channel layer is a metal mesh placed on the sinking trough, or is a flow channel etched on the bottom of the sinking trough.

[0022] Furthermore, the metal mesh includes a coarse mesh and a fine mesh, which are stacked.

[0023] Furthermore, the first end plate and / or the second end plate provided with a water inlet, a hydrogen inlet and an oxygen-water inlet, and sealing water lines are provided at the water inlet, the hydrogen inlet and the oxygen-water inlet.

[0024] Furthermore, the sealing waterline is concave downward or convex upward, and is provided with 2-4 lines.

[0025] At the same time, the present invention also provides a method for manufacturing a PEM electrolyzer:

[0026] Prepare the end plate assembly, the electrode plate assembly, and the membrane electrode as described above;

[0027] Using vulcanized rubber to wrap and seal each of the electrode plates to form an electrode plate with an electrode plate sealing structure;

[0028] Use tooling to stack and press the front and rear end plates, several plates and membrane electrodes in a fixed order.

[0029] After adopting the above technical scheme, the present invention has positive effects: (1) The present invention uses vulcanized rubber to seal the pole plate, saving 4 sealing frames, 6 sealing gaskets, and 2 insulating plates, while also having the function of outer insulation. Therefore, on the basis of meeting performance requirements, it greatly saves costs.

[0030] (2) The structural design of the present invention makes the manufacturing process simpler, the assembly is convenient, and automated production can be achieved.

[0031] (3) The rubber coating layer and the protrusions of the present invention can deform inward when the structural plane is compressed, which can firstly achieve a sealing effect and secondly withstand the pressure generated when gas is generated inside. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments and in conjunction with the accompanying drawings, wherein

[0033] Figure 1 It is a three-dimensional diagram of the PEM electrolyzer of the present invention.

[0034] Figure 2 for Figure 1 Front view of .

[0035] Figure 3 for Figure 2 AA section view.

[0036] Figure 4 for Figure 3 Enlarged view of point o.

[0037] Figure 5 It is a schematic diagram of the first end plate of the present invention.

[0038] Figure 6 for Figure 5 BB cross-sectional view.

[0039] Figure 7 for Figure 6 Enlarged view of point a.

[0040] Figure 8 Schematic diagram of the cathode plate with the plate sealing structure of the invention.

[0041] Fig. 9 for Figure 8 Front view of .

[0042] Fig.10 for Fig. 9 CC cross-sectional view.

[0043] Fig.11 for Fig.10 Enlarged view of point b.

[0044] Fig.12 for Fig.10 Enlarged view of point c.

[0045] Fig.13 Schematic diagram of the cathode plate of the present invention.

[0046] Fig.14 Schematic diagram of the bipolar plate with plate sealing structure of the invention.

[0047] Fig.15 It is a schematic diagram of the bipolar plate of the present invention facing the anode plate side.

[0048] Fig.16 It is a schematic diagram of the bipolar plate of the present invention facing the cathode plate side.

[0049] Fig.17 Schematic diagram of an anode plate with a plate sealing structure according to the present invention.

[0050] Fig.18 Schematic diagram of the anode plate of the present invention.

[0051] Fig.19 It is a schematic diagram of the second end plate of the present invention.

[0052] The numbers in the accompanying drawings are as follows:

[0053] End plate assembly 100, first end plate 110, second end plate 120, water inlet 130, oxygen water inlet 140, hydrogen inlet 150, sealing water line 160, end plate fixing port 170;

[0054] Plate assembly 200, anode plate 210, anode plate terminal 211, anode plate water port 212, anode plate oxygen water port 213, anode plate hydrogen port 214, anode plate fixing port 215, anode plate sinking tank 216, cathode plate 220, cathode plate terminal 221, cathode plate water port 222, cathode plate oxygen water port 223, cathode plate hydrogen port 224, cathode plate fixing port 225, cathode plate sinking tank 226, bipolar plate 230, bipolar plate water port 231, bipolar plate oxygen water port 232, bipolar plate hydrogen port 233, bipolar plate fixing port 234, bipolar plate sinking tank 235;

[0055] Membrane electrode 300;

[0056] Plate sealing structure 400, encapsulation layer 410, protrusion 420;

[0057] Fixing assembly 500;

[0058] Channel layer 600, coarse mesh plate 610, fine mesh plate 620;

[0059] Gas diffusion layer 700;

[0060] Quick-release connector assembly 800;

[0061] Mounting seat 900. DETAILED DESCRIPTION

[0062] The embodiment of the present invention provides a PEM electrolyzer to solve the technical problems of low sealing pressure and high production cost in the prior art, thereby achieving the technical effects of good sealing performance and low production cost.

[0063] The overall idea of ​​the technical solution provided by the present invention is as follows:

[0064] PEM electrolyser, comprising:

[0065] The end plate assembly comprises a first end plate and a second end plate; the first end plate and / or the second end plate are provided with a water inlet, a hydrogen inlet and an oxygen water inlet;

[0066] A plate assembly; comprising N plates, the N plates being located between the first end plate and the second end plate; N being a natural number, greater than or equal to 2; the plate assembly comprising an anode terminal and a cathode terminal; a water inlet, a hydrogen inlet and an oxygen-water inlet are provided at positions of the N plates corresponding to the water inlet, the hydrogen inlet and the oxygen-water inlet of the end plate assembly;

[0067] Membrane electrode; comprising N-1 membrane electrodes, wherein the N-1 membrane electrodes are spaced between two of the electrode plates; the membrane electrode and the electrode plate assembly constitute N-1 electrolysis chambers, wherein the N-1 electrolysis chambers include at least one hydrogen evolution reaction chamber and one oxygen evolution reaction chamber;

[0068] A plate sealing structure is arranged on the N plates, and the plate sealing structure uses vulcanized rubber to wrap and seal each plate.

[0069] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0070] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0071] (Example 1)

[0072] See Figure 1-4 The plate assembly 200 of this embodiment has three plates, specifically:

[0073] Figure 1-4 The PEM electrolyzer comprises: an end plate assembly 100, a plate assembly 200, a membrane electrode 300, a plate sealing structure 400, a fixing assembly 500, a flow channel layer 600, a gas diffusion layer 700, a quick-tightening joint assembly 800 and a mounting seat 900.

[0074] like Figure 1 In the specific embodiment shown, the two end faces of the PEM electrolyzer are end plate assemblies 100, and the plate assemblies and membrane electrodes are stacked and clamped in the end plate assemblies 100. The end plate assembly 100 includes a first end plate 110 and a second end plate 120, and in this embodiment, aluminum alloy is selected. The plate assembly 200 includes an anode plate 210, a cathode plate 220 and a bipolar plate 230. There are two membrane electrodes 300, which are located between the anode plate 210 and the bipolar plate 230, and between the cathode plate 220 and the bipolar plate 230. The number of membrane electrodes 300 = the number of plates - 1. The end plate assembly 100 is provided with fixing holes, and the stacked plates and membrane electrodes are fixed by passing the fixing assembly 500 (bolts and nuts) through the fixing holes. A mounting seat 900 is provided on one side of the first end plate 110, and of course it can also be provided on one side of the second end plate 120. The location of the mounting seat 900 is determined according to actual needs and there is no restriction. At the oxygen and water inlet, hydrogen inlet and water outlet, quick-tightening joint assembly 800 is provided for sealing and connecting with pipelines. Figure 1-2 As shown, an anode terminal 211 is disposed on the anode plate 210 , and a cathode terminal 221 is disposed on the cathode plate 220 . Figure 3The side of the PEM electrolyzer is clearly shown, and in particular, it can be clearly seen how the end plate assembly 100, the electrode plate assembly 200, the membrane electrode 300, the electrode plate sealing assembly 400, the fixing assembly 500, the quick-tightening joint assembly 800 and the mounting base 900 are stacked and fixed together. Figure 4 It can be clearly seen in the partial cross-sectional enlarged view that each electrode plate is provided with a depression at a relative position to form an electrolysis chamber. In this embodiment, there are two electrolysis chambers, a hydrogen evolution reaction chamber is formed between the bipolar plate 230 and the cathode plate 220, and an oxygen evolution reaction chamber is formed between the bipolar plate 230 and the anode plate 210. The anode terminal 211 and the cathode terminal 221 are respectively connected to the positive and negative electrodes of the power supply, and are connected in series with the power supply. The current passing through is the same for each electrolysis chamber (a small amount of current leakage), and the total voltage is the sum of the voltages of all electrolysis chambers.

[0075] Hydrogen evolution reaction at the cathode: 4HO+4e=2H↑+4OH

[0076] Oxygen evolution reaction at the anode: 4OH-4e=2HO+O↑

[0077] Figure 4 The plate sealing structure 400 can also be seen in the figure. It can be seen that the anode plate 210, the cathode plate 220 and the bipolar plate 230 are all provided with a rubber coating 410 on the outside, and then three protrusions 420 are provided at the recessed edge. Each protrusion 420 is inclined outward from the edge of the plate to the center of the plate, and the vertical projection of the highest point of the protrusion 420 on the rubber coating 410 serves as another edge of the protruding part of the protrusion 420, that is, the cross section of the protrusion 420 is a right triangle (of course, it can also be an acute / obtuse triangle, but a right triangle is easier to press inward to form an inward sealing ring, while an acute angle cannot be pressed and can only collapse, and an obtuse triangle will increase the process difficulty when demolding, so a right triangle is preferred in this embodiment). The thickness of the rubber layer is related to the insulation effect / voltage rating. The higher the voltage rating, the thicker the rubber layer needs to be. However, the thicker the thickness, the larger the size of the PEM electrolyzer will be, and the higher the production cost will be. The rubber layer material should have a higher resistivity and breakdown voltage, and fewer flaws and defects. In this embodiment, EPDM is the best choice for vulcanized rubber. The height of the protrusion 420 structure is related to the compression of the rubber layer, which is determined by the external applied pressure, the hardness and rebound of the rubber layer material. The spacing between the protrusions is related to the size of the overall design. After a lot of calculations and experiments, in this embodiment, the height of the protrusion 420 is about 20% of the thickness of the part of the rubber layer 410 that is connected to the protrusion 420, and the compression ratio is ≥15%, so the leakage rate is controlled to be less than 1.3X10-10Pa*m 3 / s. Considering the convenience of processing, the stability and reliability of the structure, and the uniformity of the force seal, the three protrusions 410 are arranged equidistantly, and the spacing between adjacent protrusions 410 is selected to be 0.5mm. In the inventive concept of the present application, the use of vulcanized rubber to seal and insulate the plate to reduce the use of sealing frames, etc., is the most core and critical. The triangular structure of the protrusion 420 deforms when subjected to external pressure, which increases the dynamic stability of the sealing ring and reduces the leakage rate.

[0078] The first end plate 110 and / or the second end plate 120 are provided with a water inlet 130, an oxygen water inlet 140, a hydrogen inlet 150 and an end plate fixing port 170. Figure 5 and Fig.19 In this embodiment, the water inlet 130, the oxygen water inlet 140, and the hydrogen inlet 150 are all arranged on the first end plate 110, so that only the end plate fixing port 170 is arranged on the second end plate 120, and thus, the second end plate 120 does not need to consider the sealing problem. The positions of the end plate fixing ports 170 on the first end plate 110 and the second end plate 120 correspond one to one, and correspond one to one to the fixing ports on each plate of the plate assembly, thereby facilitating the bolts in the fixing assembly 500 to pass through each fixing port, and then fix the end plate assembly 100 and the plate assembly 200 together. The installation bolts originally required heat shrink tubing for insulation, but now due to the rubber coating treatment (the fixing ports through which the installation bolts pass are all rubber coated to meet the insulation requirements), the heat shrink tubing can be omitted and the cost of the work station can be omitted. .

[0079] like Figure 5-Figure 7 As shown, the first end plate 110 is provided with sealing water lines 160 at the water inlet 130, the oxygen-water inlet 140 and the hydrogen inlet 150. In this embodiment, the sealing water line 160 is recessed into the first end plate 110. When the pole plates are stacked and press-fitted with the first end plate 110 and the cathode plate 220, the rubber coating on the cathode plate 220 will be embedded in the sealing water line 160, thereby achieving a good line seal and preventing leakage of internal fluid when there is internal pressure. The sealing water line 160 can be provided with multiple paths, and three paths are provided in this embodiment. Of course, the sealing water line 160 can also adopt an outward protrusion, and when pressed, the protruding part is embedded in the rubber coating, but the processing cost of such a process will be higher than that of milling out three recessed sealing water lines. Figure 7 As shown, the cross section of each sealing waterline 160 is V-shaped. This type of sealing waterline is the most convenient to process, and because the diameter gradually decreases, the sealing effect will be better.

[0080] Figures 8 to 18They are all structural diagrams of each plate of the plate assembly, including plates with and without rubber coating. Considering the need for corrosion resistance, each plate of the plate assembly is preferably made of titanium alloy. It is also acceptable to use a stainless steel plate with a surface coating, but the service life is shorter. In this embodiment, the plate assembly 200 includes three plates, and the three plates are located between the first end plate 110 and the second end plate 120, specifically an anode plate 210, a cathode plate 220, and a bipolar plate 230. The anode plate 210 and the cathode plate 220 are both provided with a sinking groove in the middle of one side, and the bipolar plate 230 is provided with a sinking groove on both sides; the sinking grooves of adjacent plates are relatively arranged to form a cavity serving as an electrolysis chamber. In practice, the number of bipolar plates 230 can be increased, and multiple bipolar plates 230 can be stacked between the anode plate 210 and the cathode plate 220 to form more electrolysis chamber cavities, such as anode plate-bipolar plate 1-bipolar plate 2-bipolar plate n-cathode plate. The membrane electrode can be placed in the electrolysis chamber cavity formed in the middle of the two polar plates.

[0081] in, Figure 8-Figure 13 The cathode plate 220 including the plate sealing structure and the cathode plate 220 itself are shown. The structure of the cathode plate 220 itself is shown in FIG. Fig.13 , a cathode plate sinking groove 226 is provided in the middle of one side. When assembled, the side with the cathode plate sinking groove 226 faces the bipolar plate 230, and the plane side without the cathode plate sinking groove 226 faces the first end plate 110. Eight cathode plate fixing ports 225 are provided on the cathode plate 220, which correspond to the positions of the fixing ports of other plates and end plates. At the same time, a cathode plate water port 222, a cathode plate oxygen water port 223, and a cathode plate hydrogen port 224 are also provided. In this embodiment, they are all through holes, and the positions of the settings correspond to the positions of the water port 130, the oxygen water port 140, and the hydrogen port 150 of the first end plate 110, and also correspond to the positions of the corresponding ports on the anode plate 210 and the bipolar plate 230. Since the hydrogen evolution reaction occurs on this side of the cathode plate 220, only hydrogen is produced, and no oxygen port and water port are required, the cathode plate sinking groove 226 of the cathode plate 220 only needs to surround the cathode plate hydrogen port 224. from Figure 8It can be seen that the rubber coating layer 410 covers the entire edge of the cathode plate 220, and the middle cathode plate sinking groove 226 does not need rubber coating, because the sinking groove part needs to be able to conduct current. Therefore, the rubber coating layer 410 covers the surrounding areas of the cathode plate water inlet 222 and the cathode plate oxygen water inlet 223, and covers the outer part of the cathode plate hydrogen inlet 224, while the inner side is integrated with the cathode plate sinking groove 226 and is not covered. Thus, the rubber coating layer 410 forms a complete rubber sealing ring for the cathode plate 220. A protrusion 420 is set on the rubber coating layer 410 at the cathode plate water inlet 222, the cathode plate oxygen water inlet 223, and the cathode plate hydrogen inlet 224. At the same time, a protrusion 420 is set on the surface of the rubber coating layer at the connection between the cathode plate sinking groove 226 and the plate body, and the protrusion 420 is connected to the rubber coating layer 410 as a whole. The shape of the protrusion 420 is as follows: Fig.11 and Fig.12 The other parameters such as dimensions have been introduced before and will not be repeated here.

[0082] Figure 17-Figure 18 The anode plate 210 including the plate sealing structure and the anode plate 210 itself are shown. The structure of the anode plate 210 itself is shown in FIG. Fig.18 , an anode plate sinking groove 216 is provided in the middle of one side. During assembly, the side provided with the anode plate sinking groove 216 faces the bipolar plate 230, and the flat side without the anode plate sinking groove 216 faces the second end plate 120. Eight anode plate fixing ports 215 are provided on the anode plate 210, which correspond to the positions of the fixing ports of other plates and end plates. Anode plate water inlets 212 and anode plate oxygen water inlets 213 are also provided, and the position of the anode plate hydrogen inlet 214 is reserved, and the setting position corresponds to the positions of the water inlet 130, oxygen water inlet 140, and hydrogen inlet 150 of the first end plate 110, and also corresponds to the positions of the corresponding ports on the anode plate 210 and the bipolar plate 230. In the present embodiment, the anode plate water inlet 212 and the anode plate oxygen water inlet 213 are both blind holes. Since hydrogen is not generated on the anode plate 210 side, and in the present embodiment, the second end plate 120 corresponding to the anode plate 210 is not provided with a corresponding hydrogen inlet / oxygen water inlet / water inlet. Therefore, the anode plate in the present embodiment does not need to be provided with a through hole at the hydrogen inlet / oxygen water inlet / water inlet position. If a through hole is provided, it will increase the difficulty of sealing the second end plate 120. In the embodiment, the cathode plate sinking groove 226 of the anode plate 220 is connected to the edge of the anode plate water inlet 212 and the anode plate oxygen water inlet 213. From Fig.17It can be seen that the rubber coating 410 covers the edge of the entire anode plate 210, and the middle anode plate sinking groove 216 does not need rubber coating, because the sinking groove part needs to be able to conduct current. Therefore, the rubber coating 410 covers the outer edges of the anode plate water inlet 212 and the anode plate oxygen water inlet 213 through the protrusion 420, and the inner side is integrated with the anode plate sinking groove 216, so it is not covered, and three circles of closed protrusions 420 are set at the hydrogen port, so that the rubber coating 410 forms a complete rubber sealing ring for the anode plate 210. The shape of the protrusion 420 is Fig.11 and Fig.12 The other parameters such as dimensions have been introduced before and will not be repeated here.

[0083] The structure of the bipolar plate 230 is shown in Figure 14-16 In the embodiment, the bipolar plate 230 does not need to be provided with a terminal. Bipolar plate sinking grooves 235 are provided on both sides of the bipolar plate 230, so that the side opposite to the cathode plate 220 can be equivalent to the role of the anode plate, and the side opposite to the anode plate 210 can be equivalent to the role of the cathode plate. The bipolar plate water inlet 231, the bipolar plate oxygen water inlet 232, the bipolar plate hydrogen inlet 233, and the bipolar plate fixing port 234 are all through holes, corresponding one to one with the positions of all other corresponding holes. Because the reactions occurring on the two sides of the bipolar plate 230 are different, the side opposite to the anode plate 210 is similar to the cathode plate 220 in the setting of the sinking groove. Since only hydrogen is produced, the oxygen inlet and the water inlet are not required. Therefore, the bipolar plate sinking groove 235 on this side of the bipolar plate 230 only needs to surround the bipolar plate hydrogen inlet 233. The side opposite to the cathode plate 220 only produces oxygen and does not need a hydrogen port, so the bipolar plate sinking groove 235 on this side of the bipolar plate 230 needs to surround the bipolar plate water inlet 231 and the bipolar plate oxygen and water inlet 232. The corresponding setting of the rubber layer on the two side surfaces is also similar to the corresponding cathode plate 220 or anode plate 210.

[0084] The arrangement of the protrusions 420 on the three plates allows the protrusions 420 of the two opposite plates to be embedded in each other one by one, so that the sealing effect is better, but the precision requirements for processing and assembly will be increased.

[0085] exist Figure 4In the figure, the flow channel layer 600 and the gas diffusion layer 700 can also be seen. The flow channel 600 can be a metal mesh placed on the sinking groove of each electrode plate, or a flow channel etched on the bottom of the sinking groove. In the present embodiment, the flow channel layer 600 is a metal mesh, because the method of etching the flow channel requires a higher thickness of the electrode plate, and the cost will be higher. At the same time, the electrode plate is a titanium alloy, and the etching itself is difficult and the processing cost is also high. In the present embodiment, in order to better form the flow channel and make the reaction of each electrolytic chamber more sufficient, a stacked metal coarse mesh plate 610 and a metal fine mesh plate 620 are used. The metal mesh is preferably a titanium mesh, which has stable performance and a long service life. The gas diffusion layer 700 is made of felt.

[0086] After the end plate assembly 100 and the electrode plate assembly 200 are manufactured, the electrode plate assembly 200 is sealed with rubber using the electrode plate sealing structure 400, and then the front and rear end plates, the electrode plates, the membrane electrode 300, the flow channel layer 600 and the gas diffusion layer 700 are stacked in a fixed order using tooling, and then the PEM electrolyzer is completed by tightening with special bolts with a positioning function and pressurizing to the designed size. The sealing pressure of the PEM electrolyzer manufactured according to this application can reach 2.0 MPa.

[0087] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. PEM electrolyzer, characterized in that include: The end plate assembly comprises a first end plate and a second end plate; the first end plate and / or the second end plate are provided with a water inlet, a hydrogen inlet and an oxygen water inlet; A plate assembly; comprising N plates, the N plates being located between the first end plate and the second end plate; N being a natural number, greater than or equal to 2; the plate assembly comprising an anode terminal and a cathode terminal; a water inlet, a hydrogen inlet and an oxygen-water inlet are provided at positions of the N plates corresponding to the water inlet, the hydrogen inlet and the oxygen-water inlet of the end plate assembly; Membrane electrode; comprising N-1 membrane electrodes, wherein the N-1 membrane electrodes are spaced between two of the electrode plates; the membrane electrode and the electrode plate assembly constitute N-1 electrolysis chambers, wherein the N-1 electrolysis chambers include at least one hydrogen evolution reaction chamber and one oxygen evolution reaction chamber; A plate sealing structure is arranged on the N plates, and the plate sealing structure uses vulcanized rubber to wrap and seal each plate.

2. The PEM electrolyzer according to claim 1, characterized in that Also includes: Fixing components; The fixing assembly fixes the end plate assembly and the pole plate assembly together.

3. The PEM electrolyzer according to claim 1, characterized in that: The middle parts of the N electrode plates are all provided with sinking grooves; the sinking grooves of the adjacent electrode plates are arranged relative to each other to form a cavity serving as an electrolysis chamber.

4. The PEM electrolyzer according to claim 3, characterized in that: The electrode plate sealing structure includes a rubber coating layer and a protrusion; the protrusion is arranged on the surface of the rubber coating layer at the connection between the sinking groove of the electrode plate and the electrode plate body, and is connected to the rubber coating layer as a whole.

5. The PEM electrolyzer according to claim 4, characterized in that: At least two protrusions are provided.

6. The PEM electrolyzer according to claim 3, characterized in that Also includes: A flow channel layer is arranged in the cavity of the electrolysis chamber; the flow channel layer is a metal mesh placed on the sinking trough, or is a flow channel etched on the bottom of the sinking trough.

7. The PEM electrolyzer according to claim 6, characterized in that: The metal mesh comprises a coarse mesh and a fine mesh, which are stacked.

8. The PEM electrolyzer according to claim 1, characterized in that: The first end plate and / or the second end plate is provided with a water inlet, a hydrogen inlet and an oxygen-water inlet, and a sealing water line is provided at the water inlet, the hydrogen inlet and the oxygen-water inlet.

9. The PEM electrolyzer according to claim 8, characterized in that: The sealing waterline is concave downward or convex upward, and at least two lines are provided.

10. A method for making a PEM electrolyzer, characterized in that: Prepare the end plate assembly, the electrode plate assembly, and the membrane electrode as claimed in claim 1; Using vulcanized rubber to wrap and seal each of the electrode plates to form an electrode plate with an electrode plate sealing structure; Use tooling to stack and press the front and rear end plates, several plates, and membrane electrodes in a fixed order.

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