PEM electrolytic bath

Abstract

The invention provides a PEM electrolytic bath. The PEM electrolytic bath comprises a plurality of bipolar plates and an elastic supporting net, an anode surface and a cathode surface are respectively formed on two opposite side surfaces of the bipolar plate; a concave cathode flow field is formed on the cathode surface of the bipolar plate; and a concave anode flow field is formed on the anode surface of the bipolar plate. The elastic supporting net is limited in the anode flow field, and the side, facing the cathode flow field, of the elastic supporting net supports the membrane electrode. And a space for generating hydrogen is defined between the membrane electrode and the cathode flow field. Under the elastic action of the elastic supporting net, the membrane electrode can be supported, the structural strength of the membrane electrode is enhanced, and the membrane electrode is effectively prevented from being deformed, so that hydrogen with higher pressure can be accommodated in a cathode flow field. Therefore, on the basis of ensuring the structural strength of the membrane electrode, the PEM electrolytic bath can discharge hydrogen with higher pressure.

Description

Technical Field

[0001] The invention relates to the field of energy and chemical industry, and in particular to a PEM electrolyzer. Background Art

[0002] In the chemical industry, hydrogen is mainly used in synthetic ammonia, synthetic methanol, petroleum refining, coal chemical industry and other fields. Synthetic ammonia is synthesized from nitrogen and hydrogen under high temperature, high pressure and catalytic environment, and is the main raw material for fertilizer industry and basic organic chemical industry. Methanol is synthesized from synthesis gas under the action of catalyst and is widely used in the manufacture of chemical products such as plastics, solvents, pigments, etc. Petroleum refining reduces pollutant emissions in the process of petroleum refining through hydrogenation technology. Hydrogen can also be used to synthesize low-carbon fuels, which can replace traditional fuels in heavy freight, shipping and industrial fields.

[0003] However, the application of hydrogen in the chemical industry often requires a higher pressure. For example, the hydrogen pressure for synthesizing ammonia needs to be above 10Mpa; the pressure for synthesizing methanol needs to be above 5Mpa; the outlet pressure of mainstream water electrolysis hydrogen production is 1.4-1.6MPa, which cannot meet the direct application of hydrogen in the chemical industry, and requires a compressor to boost the pressure to the required pressure. Since the required compression is relatively high, multi-stage compression is often required to meet the boosting requirements. This not only increases the process flow and equipment investment, but also increases the operation and maintenance costs. At present, the sealing form of the electrolyzer is poor and cannot produce high-pressure hydrogen. In addition, during electrolysis, since the hydrogen side is under pressure and the oxygen side is at normal pressure, this pressure imbalance can easily cause mechanical damage to the membrane electrode, leading to equipment failure. Summary of the invention

[0004] The object of the present invention is to provide a PEM electrolyzer that can generate and discharge hydrogen at a higher pressure while ensuring the strength of the membrane electrode.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] According to one aspect of the present invention, the present invention provides a PEM electrolyzer, comprising a plurality of bipolar plates and an elastic support net; the two opposite side surfaces of the bipolar plates respectively form an anode surface and a cathode surface; the cathode surface of the bipolar plate forms a concave cathode flow field; the anode surface of the bipolar plate forms a concave anode flow field; the plurality of bipolar plates are bonded to each other; the anode surface and the cathode surface of two adjacent bipolar plates are sealed and bonded, and a membrane electrode is arranged between the anode flow field and the cathode flow field of two adjacent bipolar plates; a water guide channel passes through the outer side surface of the bipolar plate and the anode flow field; the oxygen flow channel passes through the outer side surface of the bipolar plate and the anode flow field; the hydrogen flow channel passes through the outer side surface of the bipolar plate and the cathode flow field; the elastic support net is limited in the anode flow field, and the elastic support net supports the membrane electrode on the side facing the cathode flow field.

[0007] In some embodiments of the present application, an anode titanium plate is provided in the anode flow field, one side of the anode titanium plate is adhered to the membrane electrode, and the other side is adhered to the elastic support net; the edge of the anode titanium plate is sealed and adhered to the peripheral side wall of the anode flow field.

[0008] In some embodiments of the present application, the side of the elastic support mesh facing away from the anode titanium plate is attached to a side wall of the anode flow field; the anode titanium plate is attached to the side of the elastic support mesh facing away from the cathode flow field.

[0009] In some embodiments of the present application, the elastic support mesh is a structure formed by interweaving metal titanium, and the two opposite side surfaces of the elastic support mesh are completely in contact with the anode titanium plate and the side wall of the anode flow field respectively.

[0010] In some embodiments of the present application, a cathode titanium plate is provided in the cathode flow field, and the side of the cathode titanium plate facing away from the anode flow field is adhered to the corresponding membrane electrode; the edge of the cathode titanium plate is sealed and adhered to the peripheral side wall of the cathode flow field.

[0011] In some embodiments of the present application, the hydrogen flow channel includes a main channel and a branch channel; the main channel extends along the bonding direction of the bipolar plate and passes through the two ends of the bipolar plate at both ends of the extension direction; the main channels of adjacent bipolar plates are connected; each bipolar plate is provided with a branch channel, and the branch channel passes through the main channel and the cathode flow field; a sealing gasket is sealed between the anode surface and the cathode surface of two adjacent bipolar plates; the sealing gasket surrounds the periphery of the anode flow field and the cathode flow field.

[0012] In some embodiments of the present application, grooves are provided on the anode surface and the cathode surface of the bipolar plate; the grooves surround the anode flow field and the cathode flow field; the hydrogen flow channel is located within the enclosed range of the grooves; the grooves on the opposite surfaces of adjacent bipolar plates are arranged opposite to each other; sealing rings are arranged in the grooves on the opposite surfaces of adjacent bipolar plates; the outer periphery of the sealing ring is attached to the side wall of the groove and has an interference fit with the side wall of the groove.

[0013] In some embodiments of the present application, the sealing ring is a structure made of metal material, the radial cross-section of the sealing ring is a rectangular structure, chamfers are formed at the corners of the sealing ring, and chamfers are provided at the transition points corresponding to the grooves for matching with the sealing ring.

[0014] In some embodiments of the present application, an inner circumferential wall of the groove and an outer circumference of the sealing ring are respectively provided with an insulating coating.

[0015] In some embodiments of the present application, a cathode flow layer is further provided in the cathode flow field, and a plurality of small grooves are provided on the cathode flow layer.

[0016] It can be seen from the above technical solution that the present invention has at least the following advantages and positive effects:

[0017] In the present invention, the elastic support net is limited in the anode flow field, and the elastic support net supports the membrane electrode on the side facing the cathode flow field. The membrane electrode and the cathode flow field enclose a space for generating hydrogen. The elastic effect of the elastic support net can support the membrane electrode, enhance the structural strength of the membrane electrode, and effectively prevent the membrane electrode from deforming, so that the cathode flow field can accommodate hydrogen with a higher pressure. Therefore, on the basis of ensuring the structural strength of the membrane electrode, the PEM electrolyzer can discharge hydrogen with a higher pressure.

[0018] Other features and advantages of the present application will become apparent from the following detailed description, or may be learned in part by the practice of the present application.

[0019] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings herein are incorporated into the specification and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification are used to explain the principles of the present disclosure. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure, and for ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without creative work.

[0021] Figure 1 It is a schematic structural diagram of the PEM electrolyzer of the present invention.

[0022] Figure 2 It is a cross-sectional schematic diagram of a single bipolar plate of the present invention.

[0023] Figure 3 yes Figure 2 Schematic diagram of the anode side of the structure shown.

[0024] Figure 4 It is a schematic diagram of bonding multiple bipolar plates of the present invention.

[0025] Figure 5 Schematic diagram of the cathode surface of the bipolar plate of the present invention.

[0026] Figure 6 It is a structural schematic diagram of the first embodiment of the elastic support net of the present invention.

[0027] Figure 7 It is a structural schematic diagram of the second embodiment of the elastic support net of the present invention.

[0028] Figure 8 It is a structural schematic diagram of the third embodiment of the elastic support net of the present invention.

[0029] Fig. 9 It is a structural schematic diagram of the fourth embodiment of the elastic support net of the present invention.

[0030] Fig.10 It is a structural schematic diagram of the sealing ring of the present invention.

[0031] Fig.11 It is a schematic diagram of a radial cross section of the sealing ring of the present invention.

[0032] Fig.12 It is a structural schematic diagram of the anode end plate of the present invention.

[0033] Fig.13 It is a schematic structural diagram of the cathode end plate of the present invention.

[0034] The reference numerals are as follows: 100, bipolar plate; 101, anode surface; 102, cathode surface; 110, anode flow field; 120, cathode flow field; 130, water flow channel; 140, oxygen flow channel; 150, hydrogen flow channel; 160, groove; 170, connection hole; 180, cathode flow layer; 190, sealing gasket;

[0035] 200, membrane electrode; 300, elastic support mesh; 410, anode titanium plate; 420, cathode titanium plate; 500, sealing ring; 610, anode plate; 611, anode cable connector; 620, cathode plate; 621, cathode cable connector; 710, anode end plate; 720, cathode end plate. DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this disclosure will be more comprehensive and complete and will fully convey the concept of the example embodiments to those skilled in the art.

[0037] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0038] The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the technical features involved in the various embodiments of the present application described below can be combined with each other as long as they do not conflict with each other. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be understood as limiting the present application.

[0039] The present application provides a PEM electrolyzer that can produce hydrogen by electrolyzing water. PEM water electrolysis refers to proton exchange membrane water electrolysis, the core of which is a membrane electrode composed of a proton exchange membrane and catalytic layers on both sides thereof, one side of the membrane electrode is a cathode and the other side is an anode. At the anode, water molecules lose electrons to generate oxygen and hydrogen ions. The proton exchange membrane is a selectively permeable membrane that can only conduct hydrogen ions. The hydrogen ions pass through the proton exchange membrane to the cathode, obtain electrons, and generate hydrogen.

[0040] Electrode reaction equation:

[0041] Anode: 2H2O-4e-=O2+4H +

[0042] Cathode: 4H + +4e-=2H2

[0043] Figure 1 It is a schematic structural diagram of the PEM electrolyzer of the present invention. Figure 2 It is a cross-sectional schematic diagram of a single bipolar plate of the present invention. Figure 3 yes Figure 2 Schematic diagram of the anode side of the structure shown. Figure 4 It is a schematic diagram of bonding multiple bipolar plates of the present invention.

[0044] See also Figures 1 to 4 In the present application, the PEM electrolyzer includes a bipolar plate 100. The two opposite sides of the bipolar plate 100 are an anode surface 101 and a cathode surface 102, respectively. The anode surface 101 of the bipolar plate 100 forms a concave anode flow field 110, and the cathode surface 102 of the bipolar plate 100 forms a concave cathode flow field 120. The two opposite sides of the bipolar plate 100 are concave to form concave cavities, and the anode flow field 110 and the cathode flow field 120 are formed in the two concave cavities, respectively. The anode flow field 110 is used to generate and contain oxygen, and the cathode flow field 120 is used to generate and contain hydrogen.

[0045] The bipolar plate 100 is made of titanium alloy, and the surface is plated with metal platinum for corrosion and oxidation resistance. The bipolar plate 100 is a rectangular structure or a circular structure. The anode flow field 110 and the cathode flow field 120 are circular grooves or rectangular grooves.

[0046] The bipolar plate 100 is a plate-shaped structure. The anode surface 101 and the cathode surface 102 of the bipolar plate 100 are respectively planar structures. The anode surface 101 and the cathode surface 102 are arranged parallel to each other.

[0047] In this embodiment, the anode flow field 110 and the cathode flow field 120 on the bipolar plate 100 are arranged at intervals along the first direction. A plurality of bipolar plates 100 are provided, and the plurality of bipolar plates 100 are attached to each other. The plurality of bipolar plates 100 are arranged in sequence along the first direction. A membrane electrode 200 is sandwiched between adjacent bipolar plates 100, and the membrane electrode 200 is sandwiched between the anode surface 101 and the cathode surface 102 of two adjacent bipolar plates 100. The cathode of the membrane electrode 200 faces the cathode flow field 120, and the anode of the membrane electrode 200 faces the anode flow field 110.

[0048] Multiple bipolar plates 100 are bonded to each other; the anode surface 101 and the cathode surface 102 of two adjacent bipolar plates 100 are sealed and bonded, and a membrane electrode 200 is arranged between the anode flow field 110 and the cathode flow field 120 of two adjacent bipolar plates 100. The two sides of the membrane electrode 200 are the anode flow field 110 and the cathode flow field 120, respectively. The anode flow field 110 is used to generate oxygen, and the cathode flow field 120 is used to generate hydrogen. An electrolytic cell is formed between the anode flow field 110, the membrane electrode 200 and the cathode flow field 120.

[0049] The membrane electrode 200 is sealed and disposed between the two bipolar plates 100 to isolate the anode flow field 110 and the cathode flow field 120. In one embodiment, the membrane electrode 200 is sealed and clamped between the anode surface 101 and the cathode surface 102 of the two bipolar plates 100. The size of the membrane electrode 200 is larger than the anode flow field 110 and the cathode flow field 120, and the membrane electrolysis covers the anode flow field 110 and the cathode flow field 120. The peripheral edge of the membrane electrode 200 is clamped between the two bipolar plates 100.

[0050] The bipolar plate 100 is provided with a water channel 130 , which passes through the outer side of the bipolar plate 100 and the anode flow field 110 , so as to guide the electrolyzed water into the anode flow field 110 through the water channel 130 .

[0051] In some embodiments, the water channel 130 includes a main channel and a branch channel, the main channel extends along the bonding direction of the bipolar plate 100, and penetrates the two ends of the bipolar plate 100 at both ends of its own extension direction, the branch channel penetrates the main channel and the anode flow field 110, and the main channel extends along the first direction. When multiple bipolar plates 100 are bonded to each other, the main channels of the multiple bipolar plates 100 are interconnected. When the main channel on the bipolar plate 100 outside the bonding direction of the bipolar plate 100 introduces electrolyzed water, the electrolyzed water can enter the anode flow field 110 on different bipolar plates 100 through the branch channels.

[0052] In other embodiments, a water guide channel 130 is respectively disposed on each bipolar plate 100 so as to respectively guide electrolyzed water into the water guide channel 130 .

[0053] It should be noted that the bipolar plate 100 is also provided with an oxygen flow channel 140, which passes through the outer side surface of the bipolar plate 100 and the anode flow field 110, so as to discharge the oxygen generated by the anode flow field 110 from the anode flow field 110. In some embodiments, the oxygen flow channel 140 includes a main channel and a branch channel, the main channel extends along the bonding direction of the bipolar plate 100, and passes through both ends of the bipolar plate 100 at both ends of its own extension direction, the branch channel passes through the main channel and the anode flow field 110, and the main channel extends along the first direction. When multiple bipolar plates 100 are bonded to each other, the main channels of the multiple bipolar plates 100 are interconnected. The oxygen in different anode flow fields 110 is introduced into the main channel through the branch channel, and then discharged through the main channel.

[0054] In other embodiments, an oxygen flow channel 140 is respectively disposed on each bipolar plate 100 to discharge oxygen.

[0055] Figure 5 Schematic diagram of the cathode surface of the bipolar plate of the present invention.

[0056] See also Figures 1 to 5 A hydrogen flow channel 150 is also provided on the bipolar plate 100 , and the hydrogen flow channel 150 passes through the outer side surface of the bipolar plate 100 and the cathode flow field 120 , so as to discharge the hydrogen generated by the cathode flow field 120 out of the electrolyzer.

[0057] In some embodiments, the hydrogen flow channel 150 includes a main flow channel and a branch flow channel; the main flow channel extends along the bonding direction of the bipolar plate 100 and penetrates both ends of the bipolar plate 100 at both ends of the extension direction; the main flow channels of adjacent bipolar plates 100 are connected; each bipolar plate 100 is provided with a branch flow channel, and the branch flow channel penetrates the main flow channel and the cathode flow field 120. The main flow channel extends along the first direction. When multiple bipolar plates 100 are bonded to each other, the main flow channels of multiple bipolar plates 100 are interconnected. Oxygen in different cathode flow fields 120 is introduced into the main flow channel through the branch flow channel, and then discharged through the main flow channel.

[0058] In other embodiments, each bipolar plate 100 is provided with a hydrogen flow channel 150 to separate hydrogen.

[0059] See again Figures 2 to 4In some embodiments, the anode surface 101 and the cathode surface 102 of the bipolar plate 100 are respectively provided with a sealing gasket 190 to form a seal between the two bipolar plates 100. The anode surface 101 and the cathode surface 102 of the bipolar plate 100 are respectively planar structures, and the sealing gasket 190 is clamped between the anode surface 101 and the cathode surface 102 of the two bipolar plates 100. The sealing gasket 190 is an annular structure, and the sealing gasket 190 is arranged around the anode flow field 110 and the cathode flow field 120.

[0060] See again Figures 1 to 4 The PEM electrolyzer may include a plurality of bipolar plates 100, and a membrane electrode 200 is disposed between the anode flow field 110 and the cathode flow field 120 of two adjacent bipolar plates 100. A water flow channel 130, an oxygen flow channel 140, and a hydrogen flow channel 150 are disposed on the bipolar plate 100. The anode flow field 110 and the cathode flow field 120 on both sides of the membrane electrode 200 form a mutually isolated space.

[0061] The membrane electrode 200 includes a proton exchange membrane and cathode and anode catalysts sprayed on both sides. The cathode catalyst is Pt with a spraying amount of 0.2-0.5 mg / cm2, and the anode catalyst is IrO2 with a spraying amount of 0.3-0.6 mg / cm2.

[0062] The PEM electrolyzer may also include an elastic support net 300, which is limited in the anode flow field 110, and the elastic support net 300 supports the membrane electrode 200 on the side facing the cathode flow field 120. The membrane electrode 200 and the cathode flow field 120 enclose a space for generating hydrogen. The elastic effect of the elastic support net 300 can support the membrane electrode 200, enhance the structural strength of the membrane electrode 200, and effectively prevent the membrane electrode 200 from deforming, so that the cathode flow field 120 can accommodate hydrogen with a greater pressure. Thereby, on the basis of ensuring the structural strength of the membrane electrode 200, the PEM electrolyzer can discharge hydrogen with a greater pressure.

[0063] It should be noted that the elastic support net 300 is provided with a plurality of mesh holes, and the extending direction of the mesh holes is parallel to the spacing direction between the anode flow field 110 and the cathode flow field 120. The arrangement of the mesh holes ensures that the arrangement of the elastic support net 300 does not affect the flow of oxygen in the anode flow field 110.

[0064] In some embodiments, an anode titanium plate 410 is disposed in the anode flow field 110, the edge of the anode titanium plate 410 is sealed and attached to the peripheral side wall of the anode flow field 110, and one side of the anode titanium plate 410 is attached to the membrane electrode 200. The anode titanium plate 410 is used to seal the membrane electrode 200 and the anode flow field 110, and the anode titanium plate 410 can also play a role in supporting the membrane electrode 200.

[0065] One side of the anode titanium plate 410 is attached to the membrane electrode 200, and the other side is attached to the elastic support mesh 300. The elastic support force of the elastic support mesh 300 is transmitted to the membrane electrode 200 through the membrane electrode 200, thereby preventing the elastic support mesh 300 from directly contacting the membrane electrode 200 and preventing the elastic support mesh 300 from scratching the membrane electrode 200.

[0066] Furthermore, the anode titanium plate 410 is a plate-like structure. Compared with the elastic support mesh 300 directly contacting the membrane electrode 200, the membrane electrode 200 is formed by the plate surface of the anode titanium plate 410, which can ensure that there is a larger contact area with the anode side of the membrane electrode 200, thereby dispersing the pressure on the membrane electrode 200, thereby better protecting the membrane electrode 200.

[0067] Through holes may be provided on the anode titanium plate 410 so that the oxygen generated on the membrane electrode 200 can enter the anode flow field 110 .

[0068] In some embodiments, the side of the elastic support net 300 facing away from the anode titanium plate 410 is attached to a side wall of the anode flow field 110. The two opposite sides of the elastic support net 300 are respectively against the side wall of the anode flow field 110 and the anode titanium plate 410, so that the structure of the elastic support net 300 is more stable, and the support of the elastic support net 300 to the membrane electrode 200 is more reliable.

[0069] In other embodiments, a cathode titanium plate 420 is provided on the side of the elastic support mesh 300 facing the cathode flow field 120, the edge of the cathode titanium plate 420 is sealed and attached to the peripheral side wall of the cathode flow field 120, and one side of the cathode titanium plate 420 is attached to the membrane electrode 200. The cathode titanium plate 420 is used to seal the membrane electrode 200 and the cathode flow field 120, and the cathode titanium plate 420 can also play a role in supporting the membrane electrode 200.

[0070] In another embodiment, an anode titanium plate 410 and a cathode titanium plate 420 are respectively provided on both sides of the membrane electrode 200; the anode titanium plate 410 and the cathode titanium plate 420 are respectively adhered to both sides of the membrane electrode 200, the edge of the cathode titanium plate 420 is sealed to the peripheral side wall of the cathode flow field 120, and the edge of the anode titanium plate 410 is sealed to the peripheral side wall of the anode flow field 110.

[0071] The elastic support net 300 is a structure formed by interweaving metal titanium, and the two opposite sides of the elastic support net 300 are completely attached to the side walls of the anode titanium plate 410 and the anode flow field 110. The two opposite sides of the elastic support net 300 are supported respectively, which ensures the stability of the structure of the elastic support net 300 and can fully ensure that the force acting on the anode titanium plate 410 is evenly dispersed, so that the force of the elastic support net 300 on the membrane electrode 200 is uniform and reliable.

[0072] The support of the membrane electrode 200 by the elastic support net 300 can reduce the deformation of the membrane electrode 200, thereby effectively avoiding the mutual influence of the anode flow field 110 and the cathode flow field 120 on multiple double electrodes.

[0073] Figure 6 It is a structural schematic diagram of the first embodiment of the elastic support net 300 of the present invention. Figure 7 It is a structural schematic diagram of the second embodiment of the elastic support net 300 of the present invention. Figure 8 2 is a schematic structural diagram of a third embodiment of an elastic support net 300 of the present invention. Fig. 9 2 is a schematic structural diagram of a fourth embodiment of an elastic support net 300 of the present invention.

[0074] See also Figures 6 to 9 The elastic support net 300 has a thickness of 2mm-3mm and is made of titanium. The elastic support net 300 is a mesh structure woven from multiple strands of titanium wires. The mesh structure is configured as a multi-layer elastic structure, and each strand of the wire may contain at least two wires.

[0075] The edge of the elastic support net 300 is provided with a frame, which is a ring-shaped structure, extending along the edge of the elastic support net 300 and surrounding the elastic support net 300. The frame of the elastic support net 300 is wrapped around the edge of the elastic support net 300 to enhance the structural stability and prevent the metal wire from spreading or being damaged.

[0076] The structure of the metal elastic network includes disordered type and ordered type. The ordered structure includes but is not limited to: cross type, multi-layer lattice type, and dislocation lattice type.

[0077] Disordered type: The metal wires are randomly interwoven to form elastic spaces.

[0078] Cross type: The metal wire interface is cross-shaped. When subjected to pressure, the angle of the cross changes, causing deformation.

[0079] Multi-layer grid type: Metal wires are cross-woven to form multi-layer three-dimensional grids. The grids are deformed under pressure to achieve elasticity.

[0080] Offset grid type: Metal wires are cross-woven to form multiple layers, and the squares in each layer are staggered and arranged. When under pressure, the force is more uneven and elastic deformation is more likely to occur.

[0081] Fig.10 Schematic diagram of the structure of the sealing ring 500 of the present invention. Fig.11 Schematic diagram of a radial cross section of the sealing ring 500 of the present invention.

[0082] See again Figures 1 to 11In one embodiment, a sealing gasket 190 is sealed between the anode surface 101 and the cathode surface 102 of two adjacent bipolar plates 100; the sealing gasket 190 is an annular structure, and the sealing gasket 190 surrounds the outer periphery of the anode flow field 110 and the cathode flow field 120, thereby forming a seal for the cathode flow field 120, effectively ensuring the sealing of the cathode flow field 120.

[0083] In some embodiments, a sealing ring 500 is further provided between two adjacent bipolar plates 100 to form a sealing structure between the two bipolar plates 100. Specifically, the anode surface 101 and the cathode surface 102 of the bipolar plate 100 are both provided with a groove 160; the groove 160 is an annular structure. The groove 160 surrounds the anode flow field 110 and the cathode flow field 120; the hydrogen flow channel 150 is located within the enclosed range of the groove 160; the grooves 160 on the opposite surfaces of the adjacent bipolar plates 100 are arranged oppositely; the sealing ring 500 is provided in the grooves 160 on the opposite surfaces of the adjacent bipolar plates 100; the outer periphery of the sealing ring 500 is attached to the side wall of the groove 160 and is interference fit with the groove 160. The sealing ring 500 and the side wall of the groove 160 are interference fit to form a sealing effect in the groove 160, effectively preventing the gas in the cathode flow field 120 and the anode flow field 110 from flowing out from between the two bipolar plates 100. The sealing ring 500 can effectively prevent hydrogen from flowing out from between the bipolar plates 100. The space between the two bipolar plates 100 can withstand hydrogen at a higher pressure, so that hydrogen at a higher pressure can be prepared in the electrolyzer.

[0084] The sealing ring 500 is installed in the groove 160, and the outer peripheral side of the sealing ring is closely fitted with the groove 160, so as to form an annular sealing belt on the outer periphery of the cathode flow field 120 to establish an initial seal. When hydrogen is generated and the pressure in the cathode flow field 120 increases, the sealing gasket 190 expands in its radial direction under the action of the pressure, and the sealing gasket 190 and the groove 160 are more closely fitted, producing a self-tightening effect.

[0085] In some embodiments, the sealing ring 500 is a structure made of metal material, the radial cross section of the sealing ring 500 is a rectangular structure, the corners of the sealing ring 500 are chamfered, and the transition of the corresponding groove 160 is also provided with a chamfer to match the sealing ring 500. The chamfer between the sealing ring 500 and the groove 160 is provided so that there are more fitting surfaces between the sealing ring 500 and the groove 160 to ensure the sealing effect.

[0086] When the inner side of the sealing ring 500 is subjected to force and the sealing ring 500 is deformed outward in its own radial direction, it is ensured that there is a sufficient fitting surface between the sealing ring 500 and the groove 160 to ensure the sealing effect.

[0087] In one embodiment, the sealing ring 500 may be made of carbon steel, stainless steel 304, 316, etc. The sealing ring 500 is applicable to: temperature: -200-800°C pressure: normal pressure -42Mpa.

[0088] The inner wall of the groove 160 and the outer periphery of the sealing ring 500 are respectively provided with an insulating coating to prevent the two electrodes of the electrolytic cell from short-circuiting. The insulating coating is a coating material used to make the metal surface have insulating properties. There are many materials. The following are some common types:

[0089] Organic coatings: epoxy resin, polyurethane, acrylic resin.

[0090] Inorganic coatings: ceramic coatings, such as alumina (Al2O3), zirconium oxide (ZrO2), etc.

[0091] Enamel coating: a coating formed by melting inorganic glassy materials at high temperatures and attaching them to the metal surface.

[0092] Composite coating: This type of coating combines the advantages of organic and inorganic coatings. For example, adding inorganic nanoparticles, such as silicon dioxide (SiO2) nanoparticles, to epoxy resin can improve the hardness, wear resistance and heat resistance of the coating. At the same time, the organic component ensures good adhesion and flexibility of the coating.

[0093] In some embodiments, the periphery of the bipolar plate 100 is sealed with a metal sealing ring 500, which can ensure that the maximum hydrogen pressure of 42 MPa does not leak. The embedded sealing structure of the metal sealing ring 500 effectively solves the sealing between adjacent electrolytic chambers, ensuring that the hydrogen generated by the electrolytic cell will not leak to the outside through the gaps between the bipolar plates 100.

[0094] The anode flow field 110 of the bipolar plate 100 adopts an elastic support mesh 300, which can flexibly resist the pressure generated by the cathode flow field 120 and ensure the mechanical stability of the membrane electrode 200 under a 20 MPa oxygen and hydrogen pressure difference.

[0095] On the one hand, the elastic support net 300 provides a channel for the circulation of liquid and gas. On the other hand, the elastic support net 300 is elastic and performs reverse elastic compensation for the high pressure generated by the hydrogen on the cathode side, ensuring that the deformation of the membrane electrode 200 is small and controllable, avoiding mechanical damage to the membrane and preventing internal hydrogen and oxygen from mixing and causing danger.

[0096] In some embodiments, the sealing gasket 190 is located inside the sealing ring 500 , and the material of the sealing gasket 190 includes but is not limited to EPDM, PTFE, etc. The sealing gasket 190 can prevent the liquid from contacting the sealing ring 500 .

[0097] In one embodiment, the flow guide channel, the hydrogen flow channel, and the oxygen flow channel respectively penetrate the sealing gasket 190 .

[0098] In other embodiments, sealing gaskets are respectively provided on the inner side and the outer side of the sealing ring.

[0099] A cathode flow layer 180 is also provided in the cathode flow field 120 , and a plurality of small grooves are provided on the cathode flow layer 180 .

[0100] It should be noted that, in some embodiments, a through connection hole 170 is provided on the bipolar plate 100, and a plurality of connection holes 170 are provided, and the plurality of connection holes 170 are spaced around the center of the bipolar plate 100. Bolts are passed through the connection holes 170 to connect the plurality of bipolar plates 100, so that the plurality of bipolar plates 100 are attached and connected as a whole.

[0101] In some embodiments, the two sides of the plurality of bipolar plates 100 are respectively provided with an anode plate 610 and a cathode plate 620. The anode plate 610 is provided with an anode cable connector 611, and the cathode plate 620 is provided with a cathode cable connector 621.

[0102] Fig.12 It is a schematic structural diagram of the anode end plate 710 of the present invention. Fig.13 It is a schematic structural diagram of the cathode end plate 720 of the present invention.

[0103] See also Figure 1 , Fig.12 as well as Fig.13 In some embodiments, an anode terminal plate 710 is disposed on the side of the anode plate 610 facing away from the bipolar plate 100, and a cathode terminal plate 720 is disposed on the side of the cathode plate 620 facing away from the bipolar plate 100. The connection hole 170 penetrates the two end plates and the two plates.

[0104] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0105] In this application, unless otherwise clearly specified and limited, the terms "assembly", "connection" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances. In the description of this specification, the description of the reference terms "some embodiments", "exemplarily", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, in the absence of contradiction, technicians in this field can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples.

[0106] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application. Therefore, any changes or modifications made in accordance with the claims and description of the present application should fall within the scope of the patent of this application.

Claims

1. A PEM electrolyzer, characterized in that: include: multiple bipolar plates; The two opposite sides of the bipolar plate form an anode surface and a cathode surface respectively; the cathode surface of the bipolar plate forms a concave cathode flow field; The anode surface of the bipolar plate is formed with a concave anode flow field; the multiple bipolar plates are bonded to each other; the anode surface and the cathode surface of two adjacent bipolar plates are sealed and bonded, and a membrane electrode is arranged between the anode flow field and the cathode flow field of two adjacent bipolar plates; A water-conducting channel, which passes through the outer side of the bipolar plate and the anode flow field; An oxygen flow channel and a hydrogen flow channel; the oxygen flow channel passes through the outer side of the bipolar plate and the anode flow field; the hydrogen flow channel passes through the outer side of the bipolar plate and the cathode flow field; An elastic support net is limited in the anode flow field, and the elastic support net supports the membrane electrode on a side facing the cathode flow field.

2. The PEM electrolyzer according to claim 1, characterized in that: An anode titanium plate is arranged in the anode flow field, one side of the anode titanium plate is attached to the membrane electrode, and the other side is attached to the elastic support net; the edge of the anode titanium plate is sealed and attached to the peripheral side wall of the anode flow field.

3. The PEM electrolyzer according to claim 2, characterized in that: The side of the elastic support net facing away from the anode titanium plate is attached to a side wall of the anode flow field; the anode titanium plate is attached to the side of the elastic support net facing away from the cathode flow field.

4. The PEM electrolyzer according to claim 2, characterized in that: The elastic support net is a structure formed by interweaving metal titanium, and the two opposite side surfaces of the elastic support net are completely attached to the anode titanium plate and the side wall of the anode flow field respectively.

5. The PEM electrolyzer according to claim 1, characterized in that: A cathode titanium plate is arranged in the cathode flow field, and the side of the cathode titanium plate facing away from the anode flow field is attached to the corresponding membrane electrode; the edge of the cathode titanium plate is sealed and attached to the peripheral side wall of the cathode flow field.

6. The PEM electrolyzer according to claim 1, characterized in that: The hydrogen flow channel includes a main flow channel and a branch flow channel; the main flow channel extends along the bonding direction of the bipolar plate and passes through the two ends of the bipolar plate at both ends of the extension direction; the main flow channels of adjacent bipolar plates are connected; each bipolar plate is provided with a branch flow channel, and the branch flow channel passes through the main flow channel and the cathode flow field; A sealing gasket is sealed between the anode surface and the cathode surface of two adjacent bipolar plates; the sealing gasket surrounds the outer periphery of the anode flow field and the cathode flow field.

7. The PEM electrolyzer according to claim 6, characterized in that: The anode surface and the cathode surface of the bipolar plate are both provided with grooves; the grooves surround the anode flow field and the cathode flow field; the hydrogen flow channel is located within the enclosed range of the grooves; The grooves on the opposite surfaces of the adjacent bipolar plates are arranged opposite to each other; sealing rings are arranged in the grooves on the opposite surfaces of the adjacent bipolar plates; the outer periphery of the sealing ring is attached to the side wall of the groove and has an interference fit with the side wall of the groove.

8. The PEM electrolyzer according to claim 7, characterized in that: The sealing ring is a structure made of metal material, and the radial cross-section of the sealing ring is a rectangular structure. Chamfers are formed at the corners of the sealing ring, and chamfers are provided at the transition points corresponding to the grooves to match the sealing ring.

9. The PEM electrolyzer according to claim 7, characterized in that: The inner circumferential wall of the groove and the outer circumference of the sealing ring are respectively provided with insulating coatings.

10. The PEM electrolyzer according to claim 1, characterized in that: A cathode flow layer is also arranged in the cathode flow field, and a plurality of small grooves are opened on the cathode flow layer.

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