Porous diffusion layer structure, electrolysis cell and electrolytic bath

Abstract

The invention provides a porous diffusion layer structure, an electrolysis cell and an electrolytic bath, the electrolysis cell comprises the porous diffusion layer structure, a pole plate assembly, a circulation opening, a runner structure and a cavity, the circulation opening, the runner structure and the cavity are formed in the pole plate assembly, the circulation opening and the cavity are communicated through the runner structure, and the porous diffusion layer structure comprises a diffusion substrate; the diffusion substrate comprises a central part and an edge part connected to the periphery of the central part, the central part is provided with a plurality of through holes, the edge part is provided with at least one notch, the porous diffusion layer structure is arranged in the cavity, the edge part is connected to the inner periphery of the polar plate assembly, and the notch is arranged corresponding to the flow channel structure, so that the problem of flow obstruction of fluid at the flow channel structure can be effectively relieved; the flow resistance of fluid is reduced, water inlet and outlet pressure is reduced, the flow rate and water flow of the fluid are increased, and the electrolytic efficiency and overall performance of the electrolytic bath are improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydrogen production by electrolysis, and in particular to a porous diffusion layer structure, an electrolysis chamber and an electrolysis cell. Background Art

[0002] New energy has received extensive attention as a key research and development area. Hydrogen energy, as a pollution-free and renewable energy, has become one of the future energy sources. Compared with the material pollution caused by the storage of electric energy, hydrogen energy can store its chemical energy in the form of hydrogen, which has the advantages of being pollution-free and green. An electrolyzer is a device that converts electrical energy into chemical energy. When the electrolyzer is powered on, water can be electrolyzed into hydrogen and oxygen, and electrical energy can be converted into chemical energy. Therefore, the electrolyzer can use the surplus and difficult-to-store part of the electrical energy to prepare hydrogen for storage, thus avoiding energy waste. As a highly promising and sustainable clean energy technology, proton exchange membrane electrolyzer technology has made great progress in technology maturity and commercialization in the past few decades. Further exploration and optimization are needed for the real application of proton exchange membrane electrolyzers, improving the performance of electrolyzers, reducing the cost of electrolyzers, and maintaining long-term stable operation of electrolyzers. During the working process of the electrolyzer, pure water needs to be continuously input as the "raw material" for electrolysis, and the electrolyzer needs to be powered on. Therefore, the electrolyzer is a complex workbench that integrates "electricity, water, gas, and heat". In order to improve the energy conversion efficiency and performance optimization of the electrolyzer, the design of the electrolyzer is an extremely important link.

[0003] In the existing design, the anode diffusion layer of the electrolyzer usually adopts a multilayer metal mesh, such as a stretched titanium mesh or a woven titanium mesh, etc., and the assembly process is complicated and the cost is high. In this regard, the applicant discloses a bipolar plate, an electrolysis chamber and an electrolyzer in a patent application (CN117626311A), and specifically discloses a porous metal plate with a closed surface, which is made of a metal plate integrally processed, and the central area of ​​the metal plate is provided with a plurality of hole structures, so it has the function of a diffusion layer, and the assembly process can be simplified at the same time, reducing costs. However, in order to facilitate assembly, the edge portion of the porous metal plate is a solid structure, and under the pressure of installation and tightening, the edge portion of the porous metal plate is fitted at the flow port of the electrolyzer, which will cause the edge portion to hinder the circulation of the fluid at the flow port, increase the flow resistance, reduce the flow rate of the fluid, and even cause the problem of blocking the fluid (the edges of the conventional stretched titanium mesh, woven titanium mesh and titanium felt are all porous structures, so there will be no problem of blocking the fluid), thereby reducing the electrolysis efficiency.

[0004] Therefore, how to improve the existing electrolytic cell structure to effectively solve the above problems is one of the research directions of those skilled in the art. Summary of the invention

[0005] In view of this, the present application provides a porous diffusion layer structure, an electrolytic chamber and an electrolytic cell that can effectively solve the above problems.

[0006] The present application provides a porous diffusion layer structure, including a diffusion substrate, wherein the diffusion substrate includes a central portion and an edge portion connected to the periphery of the central portion, the central portion is provided with a plurality of through holes, and the edge portion is provided with at least one notch.

[0007] In one embodiment, the edge portion is bent toward one side relative to the central portion.

[0008] In one embodiment, the edge portion includes a bent portion and a straight portion, the bent portion is connected between the straight portion and the central portion, the bent portion is inclined relative to the central portion, and the straight portion is parallel to the central portion.

[0009] The present application also provides an electrolysis chamber, comprising the porous diffusion layer structure as described above, a pole plate assembly, and a flow port, a flow channel structure, and a cavity provided in the pole plate assembly, wherein the flow port and the cavity are connected through the flow channel structure, the porous diffusion layer structure is provided in the cavity, the edge portion is connected to the inner periphery of the pole plate assembly, and the recess is provided corresponding to the flow channel structure.

[0010] In one embodiment, a gap is formed between the edge of the central portion and the inner periphery of the electrode assembly, and the gap is communicated with the recess.

[0011] In one embodiment, the electrode assembly includes a connected electrode plate and a frame, a lip is provided on the inner periphery of the frame, the edge portion includes a bent portion bent toward one side of the electrode plate and a straight portion connected to the bent portion, the straight portion is connected to the side of the lip close to the electrode plate, the gap is formed between the lip and the edge of the center portion, and the flow channel structure includes a first flow channel provided on the side of the frame opposite to the electrode plate or a second flow channel provided on the side of the electrode plate opposite to the frame.

[0012] In one embodiment, the electrode assembly includes an electrode plate, the flow channel structure includes a second flow channel disposed on a side of the electrode plate opposite to the diffusion substrate, and the edge portion is connected to a side of the electrode plate located on the second flow channel.

[0013] In one embodiment, the electrolysis chamber includes a diffusion layer, which is connected to the side of the porous diffusion layer structure away from the flow channel structure, and the flow channel structure is connected to the diffusion layer through the recess and the gap; and / or, the central part also includes a solid part located between the plurality of through holes, and the electrode plate is located on one side of the cavity and is provided with a guide structure, the guide structure includes a plurality of protrusions and guide channels formed between the plurality of protrusions, and the protrusions are connected to the solid part.

[0014] In one embodiment, the electrolysis chamber includes a frame sealing layer, which is connected between the electrode plate and the frame, and a concave cavity is formed between the central portion and the bent portion, and the height of the concave cavity is equal to the sum of the thickness of the lip and the thickness of the frame sealing layer.

[0015] The present application also provides an electrolytic cell, comprising the electrolytic chamber as described above.

[0016] In summary, the present application provides a porous diffusion layer structure, an electrolytic chamber and an electrolytic cell. The electrolytic chamber includes a porous diffusion layer structure, a plate assembly, and a flow port, a flow channel structure and a cavity provided on the plate assembly. The flow port and the cavity are connected through the flow channel structure. The porous diffusion layer structure includes a diffusion substrate. The diffusion substrate includes a central portion and an edge portion connected to the periphery of the central portion. The central portion is provided with a plurality of through holes, and the edge portion is provided with at least one recess. The porous diffusion layer structure is provided in the cavity, and the edge portion is connected to the inner periphery of the plate assembly. The recess corresponds to the flow channel structure, which can effectively alleviate the flow obstruction problem of the fluid at the flow channel structure, reduce the flow resistance of the fluid, reduce the inlet and outlet water pressure, increase the flow rate and water flow of the fluid, and improve the electrolysis efficiency and overall performance of the electrolytic cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a three-dimensional schematic diagram of the porous diffusion layer structure of the present application.

[0018] Figure 2 for Figure 1 Front view of the porous diffusion layer structure.

[0019] Figure 3 for Figure 1 Side cross-sectional view of the porous diffusion layer structure.

[0020] Figure 4 for Figure 3 Enlarged schematic diagram of part A.

[0021] Figure 5 It is a three-dimensional schematic diagram of a partial structure of an electrolysis chamber (the flow channel structure is arranged on the frame) in one embodiment of the present application.

[0022] Figure 6 for Figure 5 Schematic diagram of the exploded view of the electrolysis chamber.

[0023] Figure 7 for Figure 5 Rear view of the middle frame and porous diffusion layer structure.

[0024] Figure 8 for Figure 7 Schematic diagram of the enlarged portion B.

[0025] Fig. 9 for Figure 7 A partial cross-sectional view of the connection between the middle frame and the porous diffusion layer structure.

[0026] Fig.10 for Figure 5 Schematic diagram of the middle frame and porous diffusion layer structure.

[0027] Fig.11 for Fig.10 Schematic diagram of the enlarged portion C.

[0028] Fig.12 for Figure 5 Schematic diagram of the middle frame, porous diffusion layer structure and diffusion layer.

[0029] Fig.13 for Figure 5 Partial cross-sectional view of the electrolysis chamber.

[0030] Fig.14 It is a three-dimensional schematic diagram of a partial structure of an electrolysis chamber (the flow channel structure is arranged on the electrode plate) in another embodiment of the present application.

[0031] Fig.15 for Fig.14 Schematic diagram of the exploded view of the electrolysis chamber.

[0032] Fig.16 for Fig.14 Partial cross-sectional view of the electrolysis chamber.

[0033] Fig.17 for Fig.14 Schematic diagram of the structure of the middle frame, electrode plates and porous diffusion layer.

[0034] Fig.18 for Fig.14 Partial cross-sectional view of the middle frame, electrode plates and porous diffusion layer structure.

[0035] Fig.19 This is a schematic diagram of an exploded view of an electrolysis chamber in one embodiment of the present application.

[0036] Figure identification: 10-porous diffusion layer structure; 12-diffusion substrate; 121-first side; 122-second side; 14-central portion; 141-solid portion; 16-edge portion; 18-through hole; 181-first hole combination; 182-second hole combination; 20-recess; 22-bend portion; 24-straight portion; 26-cavity; 30-electrolysis chamber; 301-anode plate; 302-anode frame sealing layer; 303-first anode diffusion layer; 304-second anode diffusion layer; 305-anode frame; 306-anode sealing layer; 307-proton exchange Membrane; 308-cathode sealing layer; 309-cathode frame; 310-cathode diffusion layer; 311-cathode frame sealing layer; 312-cathode plate; 321-polar plate; 322-frame; 341-first water inlet; 342-first water outlet; 343-second water inlet; 344-second water outlet; 361-first flow channel; 362-second flow channel; 381-first cavity; 382-second cavity; 40-diffusion layer; 42-gap; 44-first lip; 46-second lip; 48-guiding structure; 481-protrusion; 482-guiding channel. DETAILED DESCRIPTION

[0037] Before describing the embodiments in detail, it should be understood that the present application is not limited to the detailed structure or component arrangement described below or in the drawings in the present application. The present application may be an embodiment implemented in other ways. Moreover, it should be understood that the words and terms used herein are only used for descriptive purposes and should not be interpreted restrictively. The words "including", "comprising", "having" and the like used herein are meant to include the items listed thereafter, their equivalents and other additional items. In particular, when describing "a certain element", the present application does not limit the number of the element to one, but may also include multiple elements.

[0038] Please also refer to Figure 1 and Figure 2 As shown, the present application provides a porous diffusion layer structure 10, including a diffusion substrate 12. The diffusion substrate 12 is, for example, a metal plate made of metal material and processed in one piece, and can be used in an electrolytic chamber and an electrolytic cell as an anode diffusion layer or a cathode diffusion layer. In this embodiment, the diffusion substrate 12 is square as a whole. In other embodiments, the diffusion substrate 12 can also be designed in other shapes. Specifically, the diffusion substrate 12 includes a central portion 14 and an edge portion 16 connected to the periphery of the central portion 14. The central portion 14 is provided with a plurality of through holes 18 penetrating along the thickness direction. The through holes 18 are used for the flow of fluids such as gas, liquid, etc. on both sides of the diffusion substrate 12. The edge portion 16 is provided with at least one recess 20 that is recessed inwardly (recessed toward the central portion 14).

[0039] When the porous diffusion layer structure 10 is applied to an electrolytic chamber and an electrolytic cell, the edge portion 16 is used to connect to the inner periphery of the electrode plate or frame of the electrolytic chamber or electrolytic cell. The inner periphery of the electrode plate or frame corresponds to the edge area of ​​the cavity of the electrolytic chamber or electrolytic cell for fluid reaction and circulation. The setting position of the recess 20 can correspond to the flow channel structure of the electrolytic chamber or electrolytic cell. The flow channel structure is located at the periphery of the cavity and is connected to the cavity for fluid to flow into or out of the cavity. It can effectively alleviate the flow obstruction problem of the fluid at the flow channel structure, reduce the flow resistance of the fluid, reduce the inlet and outlet water pressure, increase the flow rate and water flow of the fluid, and improve the electrolysis efficiency and overall performance of the electrolytic cell.

[0040] In the illustrated embodiment, four recesses 20 are provided, distributed on opposite sides of the diffusion substrate 12, two recesses are provided at intervals on each side, and the recesses 20 on both sides are provided in a one-to-one correspondence. The two recesses 20 on one side can be provided corresponding to the water inlet of the electrolytic chamber or electrolytic cell, and the two recesses 20 on the other side can be provided corresponding to the water outlet of the electrolytic chamber or electrolytic cell. In other embodiments, the recesses 20 can also be provided in other numbers according to the actual design number of the water inlet and outlet of the electrolytic chamber or electrolytic cell.

[0041] Further, based on the diffusion substrate 12, a first direction x and a second direction y perpendicular to each other are set, the first direction x is, for example, the length direction of the diffusion substrate 12, the second direction y is, for example, the width direction of the diffusion substrate 12, and the four recesses 20 are, for example, arranged on opposite sides of the second direction y of the diffusion substrate 12. A plurality of through holes 18 are arranged and combined to form a first hole combination 181 and a second hole combination 182, a plurality of first hole combinations 181 and a plurality of second hole combinations 182 are respectively arranged, a plurality of first hole combinations 181 are evenly spaced along the first direction x, a plurality of second hole combinations 182 are evenly spaced along the first direction x, each first hole combination 181 extends along the second direction y, and each second hole combination 182 extends along the second direction y. The plurality of first hole combinations 181 and the plurality of second hole combinations 182 are arranged alternately with each other in the first direction x, for example, in the first direction x, the arrangement is second hole combination 182, first hole combination 181, second hole combination 182, first hole combination 181... Optionally, the subunit of the first hole combination 181 is an independent through hole 18, and the subunit of the second hole combination 182 is a petal-shaped structure of five through holes 18 arranged (four through holes 18 surround one through hole 18), and two adjacent second hole combinations 182 are mutually offset in the second direction y, that is, the subunits of two adjacent second hole combinations 182 do not correspond in the first direction x. In other embodiments, the plurality of through holes 18 may also have other arrangements.

[0042] The central portion 14 also includes a solid portion 141 located between the plurality of through holes 18. The solid portion 141 is a portion of the central portion 14 where no through holes 18 are provided. In this embodiment, the portion between two adjacent subunits of the same second hole combination 182 forms the solid portion 141. The solid portion 141 is in contact with the plate protrusions, so the solid portion 141 is arranged in different corresponding ways for different protrusions on the plate.

[0043] In the embodiment shown, Figure 3 and Figure 4 As shown, the diffusion substrate 12 has a first side 121 and a second side 122 opposite to each other, and the edge portion 16 is bent toward one side relative to the central portion 14, for example, the edge portion 16 is bent toward the second side 122 relative to the central portion 14. Specifically, the edge portion 16 includes a bent portion 22 and a straight portion 24, wherein the bent portion 22 is connected between the straight portion 24 and the central portion 14, the bent portion 22 is inclined toward the second side 122 relative to the central portion 14, and the straight portion 24 is parallel to the central portion 14, so that a concave cavity 26 is enclosed between the central portion 14 and the bent portion 22, and the concave cavity 26 is located on the second side 122 of the diffusion substrate 12. When the porous diffusion layer structure 10 is used in an electrolysis chamber, the concave cavity 26 is used to accommodate the flow channel protrusion of the electrode plate and provide a space for the fluid to flow. The notch 20 and the bent structure design of the edge portion 16 can effectively disperse and absorb the externally applied pressure, reduce the direct impact on the proton exchange membrane of the electrolytic chamber or electrolytic cell, thereby protecting the proton exchange membrane from mechanical damage and facilitating alignment installation. Preferably, when the porous diffusion layer structure 10 is installed, the side of the straight portion 24 facing away from the second side 122 is connected to the electrode plate or frame.

[0044] Please also refer to Figures 5 to 18 As shown, the present application also provides an electrolysis chamber 30, which is used to electrolyze the water to be electrolyzed to produce hydrogen and oxygen. Specifically, the electrolysis chamber 30 includes the porous diffusion layer structure 10, the electrode assembly, and the flow port, the flow channel structure, and the cavity provided in the electrode assembly, the flow port and the cavity are connected through the flow channel structure, the porous diffusion layer structure 10 is provided in the cavity, the edge portion 16 is connected to the inner periphery of the electrode assembly, and the recess 20 is provided corresponding to the flow channel structure, which can effectively alleviate the flow obstruction problem of the fluid at the flow channel structure, reduce the flow resistance of the fluid, reduce the inlet and outlet water pressure, increase the flow rate and water flow of the fluid, and improve the electrolysis efficiency and overall performance of the electrolysis chamber 30.

[0045] Among them, the electrode assembly includes a connected electrode 321 and a frame 322, and the electrolysis chamber 30 also includes a diffusion layer 40. The shape of the diffusion layer 40 is adapted to the shape of the porous diffusion layer structure 10. The diffusion layer 40 is, for example, titanium felt, metal mesh, etc. The porous diffusion layer structure 10 is connected between the electrode 321 and the frame 322. The diffusion layer 40 is connected to the side of the porous diffusion layer structure 10 away from the flow channel structure. For example, the diffusion layer 40 can be connected between the porous diffusion layer structure 10 and the frame 322, and the porous diffusion layer structure 10 and the diffusion layer 40 are in surface contact, and the conductive performance is better.

[0046] In the prior art, a porous metal plate is connected to a frame, and the porous metal plate divides the cavity in the electrolysis chamber into two parts, a metal mesh is provided in the upper cavity near one side of the frame, and the metal mesh is connected between the porous metal plate and the frame. Since the edge of the porous metal plate is a solid structure, when water enters the cavity from the circulation port, due to the barrier effect of the edge of the porous metal plate, the water can only enter the lower cavity, and then the water flows from the hole structure of the porous metal plate into the upper cavity, realizing the fluid communication between the upper and lower cavity parts, but the fluid communication with only the hole structure greatly reduces the flow efficiency of the water between the upper and lower cavity parts, and the flow resistance is large, resulting in an increase in the water resistance at the circulation port, an increase in the water inlet and outlet pressure, a reduction in the water flow rate, and ultimately a reduction in the electrolysis efficiency. Therefore, the edge of the porous metal plate will hinder the communication between the water and the metal mesh in the upper cavity, and in severe cases, the phenomenon of blocking the fluid will occur, resulting in serious consequences.

[0047] In the present application, the porous diffusion layer structure 10 is located in the cavity, so the porous diffusion layer structure 10 can divide the cavity into a first cavity portion 381 close to the frame 322 and a second cavity portion 382 close to the electrode plate 321 .

[0048] Furthermore, a gap 42 is formed between the edge of the center portion 14 and the inner periphery of the electrode assembly, the gap 42 is connected to the notch 20, and the flow channel structure is connected to the diffusion layer 40 through the notch 20 and the gap 42. Specifically, the edge portion 16 is connected to the frame 322, and a portion of the water flows into the second cavity 382 after passing through the flow channel structure, and the other portion flows into the diffusion layer 40 in the first cavity 381 through the notch 20 and the gap 42, so that the water can directly contact the diffusion layer 40 in the first cavity 381, reducing the water resistance of the water inlet and outlet, increasing the water flow rate, and effectively solving the problem that the edge of the existing porous metal plate hinders the communication between the liquid in the flow port of the frame / electrode plate and the diffusion layer. In addition, the reduction of the inlet and outlet water pressure and the increase of the inlet and outlet water volume can enhance mass transfer, timely discharge the oxygen generated in the process of electrolysis of water, avoid the temperature increase caused by heat accumulation, reduce mass transfer resistance, thereby reducing voltage loss, and improving electrolysis reaction and conversion efficiency.

[0049] In this embodiment, the circulation port includes a first water inlet 341 and a first water outlet 342 arranged on the frame 322, and a second water inlet 343 and a second water outlet 344 arranged on the pole plate 321. The first water inlet 341, the first water outlet 342, the second water inlet 343 and the second water outlet 344 are respectively arranged in two, the two first water inlets 341 and the two first water outlets 342 are arranged on opposite sides of the frame 322, the two second water inlets 343 and the two second water outlets 344 are arranged on opposite sides of the pole plate 321, and the two first water inlets 341 correspond to the positions of the two second water inlets 343, and the two first water outlets 342 correspond to the positions of the two second water outlets 344.

[0050] In some embodiments, a lip is provided on the inner periphery of the frame 322 , the straight portion 24 may be connected to a side of the lip close to the electrode plate 321 , and a gap 42 is formed between the lip and the edge of the central portion 14 .

[0051] In such Figure 5-13 In the illustrated embodiment, the flow channel structure includes a first flow channel 361 disposed on the side of the frame 322 opposite to the electrode plate 321, for example, a slot is disposed on the frame 322, a plurality of ribs are disposed in the slot at intervals, the plurality of ribs are connected to the electrode plate 321, and a first flow channel 361 is formed between the plurality of ribs, the first flow channel 361 is connected between the first water inlet 341 and the cavity and between the first water outlet 342 and the cavity. Two notches 20 are disposed corresponding to the first flow channel 361 on one side of the first water inlet 341, and the other two notches 20 are disposed corresponding to the first flow channel 361 on one side of the first water outlet 342. The lip includes a first lip 44 disposed on the inner periphery of the frame 322 corresponding to the first flow channel 361, the first lip 44 is disposed on the inner periphery of the frame 322 at one end away from the electrode plate 321, the straight portion 24 is located on one side of the first side 121 and connected to the side of the first lip 44 close to the first flow channel 361, so that the first flow channel 361 is directly connected to the second cavity 382, ​​and the gap 42 is formed between the first lip 44 and the edge of the center portion 14, so that the first flow channel 361 is indirectly connected to the first cavity 381 through the notch 20 and the gap 42. The supply of water is essential to maintaining the electrolysis process. The present application provides a gap 42 at the flow channel structure of the porous diffusion layer structure 10 and the frame 322 to improve the flow path of water, thereby increasing the amount of water in and out. This design helps to ensure that sufficient water enters the electrolysis chamber and the electrolytic cell to support the oxidation and reduction reactions on the anode side or the cathode side to generate oxygen, protons or hydrogen. In addition, appropriate water flow can also help remove the heat generated during the reaction and keep the electrolytic cell operating within an optimal temperature range. The gap 42 between the porous diffusion layer structure 10 and the frame 322 can also improve assembly efficiency.

[0052] Preferably, in order to facilitate the water in the first flow channel 361 to better flow to the second cavity 382 and to the first cavity 381 through the recess 20 and the gap 42, a fluid guide structure can be provided on the bottom wall of the recess 20 and the portion of the first lip 44 corresponding to the recess 20 or the gap 42. The fluid guide structure is, for example, a guide slope, a guide rib, a guide channel, etc. For example, a guide slope inclined toward the first cavity 381 is provided on the surface of the first lip 44 corresponding to the recess 20 or the gap 42, or the bottom wall of the recess 20 is sharpened so that the bottom wall of the recess 20 forms a conical structure, and the two sides of the cone respectively form guide slopes corresponding to the first cavity 381 and the second cavity 382, ​​which can reduce water flow resistance and facilitate the increase of water flow rate.

[0053] In such Figure 14-18 In the embodiment shown, the flow channel structure includes a second flow channel 362 disposed on the side of the electrode plate 321 opposite to the frame 322, for example, a slot is disposed on the electrode plate 321, a plurality of ribs are disposed in the slot at intervals, the plurality of ribs are connected to the frame 322, and a second flow channel 362 is formed between the plurality of ribs, and the second flow channel 362 communicates between the second water inlet 343 and the cavity and between the second water outlet 344 and the cavity. Two notches 20 are disposed corresponding to the second flow channel 362 on the side of the second water inlet 343, and the other two notches 20 are disposed corresponding to the second flow channel 362 on the side of the second water outlet 344. The lip includes a second lip 46 arranged on the inner periphery of the frame 322, and the second lip 46 is arranged on the inner periphery of the frame 322 at one end away from the pole plate 321. The straight portion 24 is located on one side of the first side 121 and is connected to a side of the second lip 46 close to the second flow channel 362, so that the second flow channel 362 is directly connected to the second cavity portion 382, ​​and a gap 42 is formed between the second lip 46 and the edge of the center portion 14, so that the second flow channel 362 is indirectly connected to the first cavity portion 381 through the recess 20 and the gap 42.

[0054] Preferably, in order to facilitate the water in the second flow channel 362 to better flow to the second cavity 382 and to the first cavity 381 through the recess 20 and the gap 42, a fluid guide structure can be provided on the bottom wall of the recess 20 and the portion of the second lip 46 corresponding to the recess 20 or the gap 42. The fluid guide structure is, for example, a guide slope, a guide rib, a guide channel, etc. For example, a guide slope inclined toward the first cavity 381 is provided on the surface of the second lip 46 corresponding to the recess 20 or the gap 42, or the bottom wall of the recess 20 is sharpened so that the bottom wall of the recess 20 forms a conical structure, and the two sides of the cone respectively form guide slopes corresponding to the first cavity 381 and the second cavity 382, ​​which can reduce water flow resistance and facilitate the increase of water flow rate.

[0055] In the illustrated embodiment, a flow guide structure 48 is provided on one side of the electrode plate 321 located in the cavity. The flow guide structure 48 includes a plurality of protrusions 481 and a flow guide channel 482 formed between the plurality of protrusions 481. The solid portion 141 of the porous diffusion layer structure 10 corresponds to and is connected to the protrusions 481. For example, the solid portion 141 and the protrusions 481 are combined by welding or other methods, which can reduce the contact resistance and make the connection between the porous diffusion layer structure 10 and the electrode plate 321 more secure and have a longer service life. The protrusion 481 can be a column or a ridge, or a combination of the two. The shape of the column is not limited and can be circular, square, elliptical, frustum-shaped, etc. The ridge can be linear, curved, or can be set to a continuous or discontinuous structure. Figure 5-13 In the embodiment shown, the protrusion 481 is a circular protrusion; Figure 14-18 In the illustrated embodiment, the protrusion 481 is a combination of a circular convex column and a linear ridge. For example, a graphic convex column is provided in the area near the water inlet and the water outlet, and the linear ridge is provided between the circular convex columns on both sides.

[0056] The present application replaces the traditional multi-layer metal mesh with a porous diffusion layer structure 10 (porous metal plate), which not only simplifies the structure and assembly process, but also the solid part 141 of the porous diffusion layer structure 10 contacts the protrusion 481 of the electrode plate 321 to reduce the contact resistance, and forms a gap 42 between the porous diffusion layer structure 10 and the frame 322 to reduce the water inlet and outlet resistance of the flow channel structure and increase the water inlet and outlet flow rate.

[0057] Preferably, the electrolysis chamber 30 includes a frame sealing layer, which is connected between the electrode plate 321 and the frame 322. The height of the cavity 26 is equal to the sum of the thickness of the lip (the first lip 44 or the second lip 46) and the thickness of the frame sealing layer, and the overall thickness of the edge portion 16 is equal to the sum of the height of the cavity 26 and the thickness of the center portion 14.

[0058] It should be pointed out that the porous diffusion layer structure 10 of the present application can be used for the anode diffusion layer of the electrolysis chamber 30, and correspondingly, the electrode plate 321 is an anode plate or a bipolar plate, and the frame 322 is an anode frame; the porous diffusion layer structure 10 can also be used for the cathode diffusion layer of the electrolysis chamber 30, and correspondingly, the electrode plate 321 is a cathode plate or a bipolar plate, and the frame 322 is a cathode frame.

[0059] like Fig.19As shown, the porous diffusion layer structure 10 is applied to the anode diffusion layer of the electrolysis chamber 30. Specifically, the electrolysis chamber 30 has an anode side and a cathode side opposite to each other. From the anode side to the cathode side, the electrolysis chamber 30 includes an anode plate 301, an anode frame sealing layer 302, a first anode diffusion layer 303, a second anode diffusion layer 304, an anode frame 305, an anode sealing layer 306, a proton exchange membrane 307, a cathode sealing layer 308, a cathode frame 309, a cathode diffusion layer 310, a cathode frame sealing layer 311 and a cathode plate 312, wherein the anode plate 301 and the cathode plate 312 can be respectively For bipolar plates, the porous diffusion layer structure 10 is the first anode diffusion layer 303, and the diffusion layer 40 can be the second anode diffusion layer 304. The second anode diffusion layer 304 is, for example, titanium felt. The second anode diffusion layer 304 and the first anode diffusion layer 303 are sequentially placed on the first lip 44 of the frame 322. A porous metal plate (porous diffusion layer structure 10) and a titanium felt diffusion layer combination are used. The porous transmission layer with a high-efficiency through-hole structure has higher performance than the traditional metal mesh, can conduct electricity better, and is in surface contact with the titanium felt. The firmness of the welding point is much greater than the line contact between the titanium felt and the metal mesh, and the service life is longer. The frame sealing layer is the anode frame sealing layer 302, and the cathode diffusion layer 310 includes carbon felt, stainless steel felt and stainless steel mesh. The proton exchange membrane 307 is coated with an anode catalyst layer on one side corresponding to the anode sealing layer 306, and the proton exchange membrane 22 is coated with a cathode catalyst layer on one side corresponding to the cathode sealing layer 308. In other embodiments, the structure of the electrolysis chamber 30 is not limited to the above-mentioned example, and the electrolysis chamber 30 may also have other structural designs.

[0060] The functional layers of the electrolysis chamber 30 are fixedly connected to each other. For example, the peripheral areas of the anode plate 301, the anode frame sealing layer 302, the anode frame 305, the anode sealing layer 306, the proton exchange membrane 307, the cathode sealing layer 308, the cathode frame 309, the cathode frame sealing layer 311 and the cathode plate 312 are respectively provided with fixing holes corresponding to each other, which can be fastened by fixing parts such as bolts.

[0061] In the above embodiments, the porous diffusion layer structure 10 is configured to be connected to the lip of the frame 322. It should be noted that in other embodiments, the porous diffusion layer structure 10 may also be directly connected to the frame 322, or the porous diffusion layer structure 10 may be directly connected to the electrode plate 321.

[0062] When the porous diffusion layer structure 10 is directly connected to the electrode 321, for example, the electrode assembly may only include the electrode 321, that is, no frame is provided, and the porous diffusion layer structure 10 is connected to the electrode 321, for example, connected to the side of the electrode 321 where the flow channel structure is provided, the flow channel structure includes a second flow channel 362 provided on the electrode 321 on the side opposite to the diffusion substrate 12, and the edge portion 16 is connected to the electrode 321 on one side of the second flow channel 362. At this time, the notch 20 is provided corresponding to the second flow channel 362, and the gap 42 is formed between the edge of the center portion 14 and the inner periphery of the electrode 321, wherein the inner periphery of the electrode 321 is defined by the projection of the edge of the cavity on the electrode 321. Further, the electrode 321 is provided with a groove on one side of the cavity, the groove constitutes a part of the cavity, and a flow guide structure may be provided in the groove, and at this time, the upper edge of the inner side wall of the groove forms the inner periphery of the electrode 321. After passing through the second flow channel 362, part of the water flows directly into the cavity space of the porous diffusion layer structure 10 away from the electrode plate 321, and the other part flows into the cavity space between the porous diffusion layer structure 10 and the electrode plate 321 through the recess 20 and the gap 42, so that the water can quickly and evenly fill the cavity space between the porous diffusion layer structure 10 and the electrode plate 321, reduce the water resistance of the water inlet and outlet, increase the water flow rate, and effectively solve the problem that the edge of the existing porous metal plate hinders the connection between the liquid in the flow port of the frame / electrode plate and the electrode plate. In addition, the reduction of the inlet and outlet water pressure and the increase of the inlet and outlet water volume can enhance mass transfer, timely discharge the oxygen generated in the process of electrolysis of water, avoid heat accumulation leading to temperature increase, reduce mass transfer resistance, thereby reducing voltage loss and improving electrolysis reaction and conversion efficiency.

[0063] Similar to the above embodiment, when the porous diffusion layer structure 10 is directly connected to the electrode 321, for example, the electrode assembly may further include the electrode 321 and the frame 322, and the porous diffusion layer structure 10 is connected to the electrode 321, or the porous diffusion layer structure 10 is connected between the electrode 321 and the frame 322, in which case the frame 322 may not be provided with a lip. When the porous diffusion layer structure 10 is connected to the electrode 321, for example, it is connected to a side of the electrode 321 where a flow channel structure is provided, the flow channel structure includes a second flow channel 362 provided on the electrode 321 on the side opposite to the diffusion substrate 12, and the edge portion 16 is connected to the electrode 321 on one side of the second flow channel 362, and the arrangement of the notch 20 and the gap 42 is similar to the above embodiment, and will not be repeated here.

[0064] It should be understood that when the porous diffusion layer structure 10 is directly connected to the electrode plate 321, the straight portion 24 is located on the side of the second side 122 and connected to the electrode plate 321, so that the cavity 26 can accommodate the protrusion 481 of the electrode plate 321 and provide space for the fluid to flow.

[0065] The present application also provides an electrolytic cell, which can be a proton exchange membrane electrolytic cell, comprising a first end plate, a second end plate and at least one electrolytic chamber as described above, wherein the at least one electrolytic chamber is stacked, and the first end plate and the second end plate are respectively arranged at the two ends of the stacking direction of the at least one electrolytic chamber, and the first end plate and the second end plate are relatively fixed, for example, fixed by bolts, so that the at least one electrolytic chamber is clamped and fixed between the first end plate and the second end plate, or the first end plate, the second end plate and the at least one electrolytic chamber are fixed together by bolts.

[0066] In summary, the present application provides a porous diffusion layer structure, an electrolytic chamber and an electrolytic cell. The electrolytic chamber includes a porous diffusion layer structure, a plate assembly, and a flow port, a flow channel structure and a cavity provided on the plate assembly. The flow port and the cavity are connected through the flow channel structure. The porous diffusion layer structure includes a diffusion substrate. The diffusion substrate includes a central portion and an edge portion connected to the periphery of the central portion. The central portion is provided with a plurality of through holes, and the edge portion is provided with at least one recess. The porous diffusion layer structure is provided in the cavity, and the edge portion is connected to the inner periphery of the plate assembly. The recess corresponds to the flow channel structure, which can effectively alleviate the flow obstruction problem of the fluid at the flow channel structure, reduce the flow resistance of the fluid, reduce the inlet and outlet water pressure, increase the flow rate and water flow of the fluid, and improve the electrolysis efficiency and overall performance of the electrolytic cell.

[0067] The concepts described herein may be implemented in other forms without departing from their spirit and characteristics. The specific embodiments disclosed should be considered illustrative rather than restrictive. Therefore, the scope of this application is determined by the appended claims rather than by the preceding description. Any changes within the literal meaning and equivalent scope of the claims should fall within the scope of these claims.

Claims

1. A porous diffusion layer structure, characterized in that: The invention comprises a diffusion substrate (12), wherein the diffusion substrate (12) comprises a central portion (14) and an edge portion (16) connected to the periphery of the central portion (14), wherein the central portion (14) is provided with a plurality of through holes (18), and the edge portion (16) is provided with at least one notch (20).

2. The porous diffusion layer structure according to claim 1, characterized in that: The edge portion (16) is bent toward one side relative to the central portion (14).

3. The porous diffusion layer structure according to claim 2, characterized in that: The edge portion (16) comprises a bent portion (22) and a straight portion (24), wherein the bent portion (22) is connected between the straight portion (24) and the central portion (14), the bent portion (22) is inclined relative to the central portion (14), and the straight portion (24) is parallel to the central portion (14).

4. An electrolysis chamber, characterized in that: It comprises a porous diffusion layer structure (10) as described in any one of claims 1 to 3, a pole plate assembly, and a flow port, a flow channel structure, and a cavity arranged in the pole plate assembly, wherein the flow port and the cavity are connected through the flow channel structure, the porous diffusion layer structure (10) is arranged in the cavity, the edge portion (16) is connected to the inner periphery of the pole plate assembly, and the recess (20) is arranged corresponding to the flow channel structure.

5. The electrolysis cell according to claim 4, characterized in that A gap (42) is formed between the edge of the central portion (14) and the inner periphery of the electrode assembly, and the gap (42) is communicated with the recess (20).

6. The electrolysis cell according to claim 5, characterized in that The electrode plate assembly comprises a connected electrode plate (321) and a frame (322); a lip is provided on the inner periphery of the frame (322); the edge portion (16) comprises a bent portion (22) bent toward one side of the electrode plate (321) and a straight portion (24) connected to the bent portion (22); the straight portion (24) is connected to a side of the lip close to the electrode plate (321); the gap (42) is formed between the lip and the edge of the central portion (14); and the flow channel structure comprises a first flow channel (361) provided on a side of the frame (322) opposite to the electrode plate (321) or a second flow channel (362) provided on a side of the electrode plate (321) opposite to the frame (322).

7. The electrolysis cell according to claim 5, characterized in that The electrode assembly comprises an electrode (321); the flow channel structure comprises a second flow channel (362) provided on a side of the electrode (321) opposite to the diffusion substrate (12); and the edge portion (16) is connected to a side of the electrode (321) located on the second flow channel (362).

8. The electrolysis cell according to claim 6 or 7, characterized in that The electrolysis chamber (30) comprises a diffusion layer (40), wherein the diffusion layer (40) is connected to a side of the porous diffusion layer structure (10) away from the flow channel structure, and the flow channel structure is connected to the diffusion layer (40) through the recess (20) and the gap (42); and / or, The central portion (14) further includes a solid portion (141) located between the plurality of through holes (18); the electrode plate (321) is provided with a flow guide structure (48) on one side of the cavity; the flow guide structure (48) includes a plurality of protrusions (481) and a flow guide channel (482) formed between the plurality of protrusions (481); the protrusions (481) are connected to the solid portion (141).

9. The electrolysis cell according to claim 6, characterized in that The electrolysis chamber (30) includes a frame sealing layer, which is connected between the electrode plate (321) and the frame (322). A concave cavity (26) is formed between the central portion (14) and the bent portion (22), and the height of the concave cavity (26) is equal to the sum of the thickness of the lip edge and the thickness of the frame sealing layer.

10. An electrolytic cell, characterized in that: It comprises an electrolysis chamber (30) as claimed in any one of claims 4 to 9.

Images