PEM electrolytic bath

Abstract

The invention discloses a PEM electrolytic bath, and relates to the technical field of electrolytic baths, the PEM electrolytic bath comprises an end plate assembly, a polar plate assembly and a membrane electrode, and the polar plate assembly and the membrane electrode are provided with an anode side water inlet and outlet channel and a cathode side water inlet and outlet channel which are respectively communicated with shunting channels of the end plate assembly. The PEM electrolytic bath provided by the invention contains few parts, is simple in structure and relatively low in processing cost, can ensure good sealing performance, and meanwhile, water can respectively enter the PEM electrolytic bath from the end plates on the two sides, so that the water inlet amount is larger, the PEM electrolytic bath has good heat dissipation performance, reactants and products can be uniformly distributed, and the electrolytic efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of electrolyzers, and in particular to a PEM electrolyzer. Background Art

[0002] A PEM electrolyzer is a water electrolysis hydrogen production device that uses a proton exchange membrane as its core electrolyte. Due to its high efficiency, flexibility, and compactness, it has become one of the mainstream technologies for water electrolysis hydrogen production. Its main components, from the inside out, are the proton exchange membrane, anode and cathode catalyst layers, gas diffusion layer, and bipolar plates.

[0003] Existing PEM electrolyzers, such as the multi-stage PEM electrolyzer with water-gas groove plates disclosed in application number 202223143772.X, mainly include a lower end plate, a lower electrode plate, at least two stacking units, a bipolar plate, an upper electrode plate, and an upper end plate, wherein the stacking unit includes a lower water-conducting layer, a lower sealing frame, a membrane electrode, an upper sealing frame, and an upper water-conducting layer stacked in sequence upward. The PEM electrolyzer has the following disadvantages: 1. There are many components and a complex structure, which makes it difficult to Ensure the connection sealing between each component; 2. Since the lower electrode plate, stacking unit, bipolar plate, upper electrode plate and upper end plate edges of the PEM electrolyzer are provided with multiple interconnected water inlet and outlet holes, the PEM electrolyzer adopts a single-sided water inlet method from the upper end plate, upper electrode plate, bipolar plate to the lower electrode plate in sequence. This not only has a small amount of water inlet and outlet, but also low electrolysis efficiency, and poor heat dissipation, making it difficult to meet the current development direction of PEM electrolyzers towards large flow and large standards. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a PEM electrolyzer, which contains fewer components, has a simple structure, and has a low processing cost. It can ensure good sealing performance. At the same time, it can take in water from the end plates on both sides, so the water intake is larger, has good heat dissipation performance, can evenly distribute reactants and products, and improve the electrolysis efficiency.

[0005] A PEM electrolyzer, characterized in that it comprises:

[0006] The end plate assembly includes two anode end plates and cathode end plates of the same structure provided on both sides, wherein the inner sides of the anode end plates and the cathode end plates are respectively provided with an inlet diversion flow channel and an outlet diversion flow channel, and the outer sides of the anode end plates and the cathode end plates are respectively provided with an inlet through-hole and an outlet through-hole corresponding to the inlet diversion flow channel and the outlet diversion flow channel;

[0007] A plate assembly comprising an anode end plate, a cathode end plate, and at least one bipolar plate structure, wherein the anode end plate and the cathode end plate are disposed between the anode end plate and the cathode end plate, and the bipolar plate structure is disposed between the anode end plate and the cathode end plate;

[0008] A membrane electrode, wherein the membrane electrode is spaced between two adjacent plates of the plate assembly, the membrane electrode and the plate assembly forming an electrolysis chamber, and the electrolysis chamber comprises at least an anode reaction chamber and a cathode reaction chamber;

[0009] The electrode plate assembly and the membrane electrode are provided with an anode side water inlet channel respectively connected to the two ends of the inlet diversion channel of the anode end plate, and the electrode plate assembly and the membrane electrode are provided with an anode side water outlet channel respectively connected to the two ends of the outlet diversion channel of the anode end plate; the electrode plate assembly and the membrane electrode are provided with a cathode side water inlet channel respectively connected to the two ends of the inlet diversion channel of the cathode end plate, and the electrode plate assembly and the membrane electrode are provided with a cathode side water outlet channel respectively connected to the two ends of the outlet diversion channel of the cathode end plate.

[0010] A first anode inlet, a second anode inlet, a first anode outlet and a second anode outlet are respectively provided near the edge of the anode end plate, the first anode inlet and the second anode inlet are connected to the two ends of the inlet shunt flow channel of the anode end plate, and the first anode outlet and the second anode outlet are connected to the two ends of the outlet shunt flow channel of the anode end plate; a first cathode inlet, a second cathode inlet, a first cathode outlet and a second cathode outlet are respectively provided near the edge of the cathode end plate, the first cathode inlet and the second cathode inlet are connected to the two ends of the inlet shunt flow channel of the cathode end plate, and the first cathode outlet and the second cathode outlet are connected to the two ends of the outlet shunt flow channel of the cathode end plate.

[0011] The bipolar plate structure includes a cathode titanium felt, a cathode titanium mesh, a polar plate, an anode titanium mesh, and an anode titanium felt. The polar plate includes two opposite side surfaces. One side surface of the polar plate is etched to form an anode flow channel area, and the other side surface of the polar plate is etched to form a cathode flow channel area. The cathode titanium felt, cathode titanium mesh, polar plate, anode titanium mesh, and anode titanium felt are stacked in sequence and welded to form an integrated bipolar plate.

[0012] The flow channel arrangement directions of the cathode flow channel region and the anode flow channel region of the electrode plate are perpendicular to each other, and both the anode flow channel region and the cathode flow channel region of the electrode plate are serpentine flow channels.

[0013] The electrode plate is provided with a water inlet and outlet, and the water inlet and outlet include 8 and are evenly arranged at the circumferential position of the electrode plate. The water inlet and outlet include two anode inlets, two anode outlets, two cathode inlets, and two cathode outlets. The two anode inlets are connected to the first anode inlet or the second anode inlet of the anode terminal plate, the two anode outlets are connected to the first anode outlet or the second anode outlet of the anode terminal plate, the two cathode inlets are connected to the first cathode inlet or the second cathode inlet of the cathode terminal plate, and the two cathode outlets are connected to the first cathode outlet or the second cathode outlet of the cathode terminal plate.

[0014] The two anode inlets are arranged at the upper left end of the electrode plate and the left side of its lower part, the two anode outlets are arranged at the lower right end of the electrode plate and the right side of its upper end, the two cathode inlets are arranged at the lower left end of the electrode plate and the left side of its upper end, and the two cathode outlets are arranged at the upper right end of the electrode plate and the right side of its lower end.

[0015] The electrode plate is provided with a through flow channel folding mouth, and the flow channel folding mouth is in a strip shape. The flow channel folding mouth includes a first flow channel folding mouth, a second flow channel folding mouth, a third flow channel folding mouth, and a fourth flow channel folding mouth. The first flow channel folding mouth is provided between the anode inlet at the lower part of the electrode plate and the anode flow channel area, the second folding mouth is provided between the anode outlet and the anode flow channel area at the upper part of the electrode plate, the third folding mouth is provided between the cathode inlet and the anode flow channel area on the right side of the electrode plate, and the fourth folding mouth is provided between the cathode outlet and the anode flow channel area on the left side of the electrode plate.

[0016] The cathode terminal plate and the anode terminal plate serve as two-pole current collecting plates.

[0017] An insulating plate is provided between the anode end plates, and an insulating plate is provided between the cathode end plates. Two water inlets and two water outlets are respectively provided on the two insulating plates. The two water inlets correspond to the two ends of the water inlet diversion channel respectively, and the two water outlets correspond to the two ends of the water outlet diversion channel respectively.

[0018] A first sealing structure is provided between the anode end plate and the insulating plate, and between the cathode end plate and the insulating plate; a symmetrically arranged second sealing structure is provided on both sides of the anode end plate and the cathode end plate; and a symmetrically arranged third sealing structure is provided on both sides of the bipolar plate assembly.

[0019] The beneficial effects of the PEM electrolyzer of the present invention are as follows: by providing an anode side water inlet and outlet channel connected to the anode end plate on the electrode assembly and the membrane electrode, and providing a cathode side water inlet and outlet channel connected to the cathode end plate on the electrode assembly and the membrane electrode, it is possible to simultaneously inlet and outlet water from the anode end plate and the cathode end plate of the PEM electrolyzer, thereby increasing the water inlet volume, and at the same time having good heat dissipation performance, being able to evenly distribute reactants and products, and improving electrolysis efficiency; wherein the end plate assembly includes two anode end plates and cathode end plates with the same structure, which can reduce the cost of mold opening processing, and the overall components of the PEM electrolyzer are few, the structure is simple, and the processing cost is reduced, and good sealing can be guaranteed when stacked and sealed.

[0020] At the same time, the bipolar plate structure of the present invention adopts an integrated structure, which further simplifies the subsequent stacking work, reduces processing costs, and at the same time reduces the contact resistance between the components, thereby improving the performance of the entire cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 1 is an exploded view of the overall structure of the PEM electrolyzer of the present invention.

[0022] Figure 2 、 3 Schematic diagrams of the two side structures of the anode end plate of the present invention.

[0023] Figure 4 、 5 Schematic diagram of the two-side structure of the anode terminal plate of the present invention.

[0024] Figure 6 Schematic diagram of the structure of the cathode terminal plate of the present invention.

[0025] Figure 7 This is an overall structural view of the bipolar plate structure of the present invention.

[0026] Figure 8 Exploded view of the bipolar plate structure of the present invention.

[0027] Figure 9 、 10 Schematic diagram of the two side structures of the electrode plate of the present invention.

[0028] Figure 11 Schematic diagram of the water inlet flow channel of the electrode assembly of the present invention.

[0029] Description of reference numerals:

[0030] 1. End plate assembly; 11. Inlet diverter channel; 12. Outlet diverter channel; 13. Inlet through-hole; 14. Outlet through-hole; 2. Anode end plate; 21. First anode inlet; 22. Second anode inlet; 23. First anode outlet; 24. Second anode outlet; 25. Anode end plate flow channel area; 26. First strip water inlet; 27. First strip water outlet; 3. Cathode end plate; 31. First cathode inlet; 32. Second cathode inlet; 33. First cathode outlet; 34. Second cathode outlet; 35. Cathode end plate flow channel area; 36. Second strip water inlet; 37. Second strip water outlet; 4. Bipolar plate structure; 41. Cathode titanium felt; 42. Cathode titanium mesh; 43. Polar plate; 431. Anode inlet; 432. Anode outlet; 433. Cathode inlet; 434. Cathode outlet; 435. First folding opening; 436. Second folding opening; 437. Third folding opening; 438. Fourth folding opening; 44. Anode titanium mesh; 45. Anode titanium felt; 5. Membrane electrode; 6. Insulating plate; 7. Fixing hole. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0032] Among them, the same parts are represented by the same figure marks. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the drawings of the present application specification, and the words "bottom" and "top", "inside" and "outside" refer to directions toward or away from specific parts, respectively. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application specification, the meaning of "multiple" is two or more.

[0033] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0034] like Figure 1 The figure shows an exploded view of the overall structure of a PEM electrolyzer, which includes:

[0035] The end plate assembly 1 includes two anode end plates and cathode end plates of the same structure, each of which has an inlet diversion channel 11 and an outlet diversion channel 12 on its inner side, and an inlet through-hole 13 and an outlet through-hole 14 on its outer side, which are connected to the inlet diversion channel 11 and the outlet diversion channel 12 respectively;

[0036] A plate assembly, comprising an anode end plate 2, a cathode end plate 3 and at least one bipolar plate structure 4, wherein the anode end plate 2 and the cathode end plate 3 are disposed between the anode end plate and the cathode end plate, and the bipolar plate structure 4 is disposed between the anode end plate 2 and the cathode end plate 3;

[0037] The membrane electrode 5 is spaced between the two plates of the plate assembly. The membrane electrode 5 and the plate assembly constitute an electrolysis chamber, which includes at least an anode reaction chamber and a cathode reaction chamber.

[0038] Among them, the electrode plate assembly and the membrane electrode 5 are provided with an anode side water inlet channel respectively connected to the two ends of the inlet diversion channel 11 of the anode end plate, and the electrode plate assembly and the membrane electrode 5 are provided with an anode side water outlet channel respectively connected to the two ends of the outlet diversion channel 12 of the anode end plate; the electrode plate assembly and the membrane electrode 5 are provided with a cathode side water inlet channel respectively connected to the two ends of the inlet diversion channel 11 of the cathode end plate, and the electrode plate assembly and the membrane electrode 5 are provided with a cathode side water outlet channel respectively connected to the two ends of the outlet diversion channel 12 of the cathode end plate.

[0039] In the prior art, the PEM electrolyzer includes a plurality of components that are stacked and assembled, with a complex structure, high processing cost, and it is difficult to ensure the sealing of the package. At the same time, the water inlet and outlet channels thereon are usually unilateral water inlet, which makes it difficult to ensure heat dissipation performance and the electrolysis efficiency is not high. In the present application, since the two anode end plates and cathode end plates located on the outermost sides have the same structure, the processing can be completed by using a set of processing molds, the processing cost is low, and the components can be replaced with each other. At the same time, in the present application, the overall components of the PEM electrolyzer are small, which is convenient for stacking and assembly, reducing the processing cost. In the PEM electrolyzer, there are anode side water inlet and outlet channels and cathode side water inlet and outlet channels respectively connected to the anode end plates and cathode end plates at both ends, so that water can be simultaneously inlet and outlet from the two side end plates of the PEM electrolyzer, so that the water inlet is larger and has good heat dissipation performance, which can better achieve the distribution consistency of reactants and products in the flow channel and improve the electrolysis efficiency.

[0040] Preferably, the end plates of the end plate assembly are square. Since the structures of the anode end plates and cathode end plates on both sides are exactly the same, the anode end plates are specifically described. Figure 2 、 3As shown in the structural diagram of the anode end plate, an inlet diversion channel 11 and an outlet diversion channel 12 are provided on the inner side of the anode end plate, and an inlet through-hole 13 and an outlet through-hole 14 are provided on the outer side of the anode end plate, which are connected to the inlet diversion channel 11 and the outlet diversion channel 12 respectively. The inlet diversion channel 11 and the outlet diversion channel 12 are approximately L-shaped. After the inlet water is introduced into the inlet diversion channel 11 through the inlet through-hole 13, the inlet water is diverted to the two ends of the channel through the L-shaped channel; the outflow water is then merged at both ends of the channel through the L-shaped channel of the outlet diversion channel 12 and flows out through the outlet through-hole 14.

[0041] Preferably, the anode terminal plate 2 and the cathode terminal plate 3 are placed between the anode terminal plate and the cathode terminal plate, and are connected to the anode terminal plate and the cathode terminal plate respectively. The anode terminal plate 2 and the cathode terminal plate 3 act as the two-pole current collector. Figure 4 、 5 As shown in the structural diagram of the anode terminal plate, it can be seen that the anode terminal plate 2 is provided with an anode terminal plate flow channel area 25 on the side away from the anode terminal plate. The anode terminal plate flow channel area 25 is a serpentine flow channel arranged in a horizontal direction. The tortuous path increases the turbulence of the fluid, which helps to better mix and promote the reaction. The other side of the anode terminal plate 2 is provided with a first anode inlet 21 and a second anode inlet 22 that are connected to both ends of the inlet branch flow channel 11 of the anode terminal plate respectively. The anode terminal plate 2 is also provided with a first anode outlet 23 and a second anode outlet 24 that are connected to both ends of the outlet branch flow channel 12 of the anode terminal plate respectively. Figure 6 As shown in the schematic structural diagram of the cathode end plate 3, a cathode end plate flow channel region 35 is provided on the side of the cathode end plate 3 away from the cathode end plate. This cathode end plate flow channel region 35 is a vertically arranged serpentine flow channel. The tortuous path increases the turbulence of the fluid, facilitating better mixing and promoting the reaction. A first cathode inlet 31 and a second cathode inlet 32 are provided on the other side of the cathode end plate 3, respectively communicating with the ends of the cathode end plate's inlet shunt flow channel 11. The cathode end plate 3 is also provided with a first cathode outlet 33 and a second cathode outlet 34, respectively communicating with the ends of the cathode end plate's outlet shunt flow channel 12.

[0042] Specifically, the anode end plate 2 is further provided with a first strip-shaped water inlet 26 and a first strip-shaped water outlet 27. The first strip-shaped water inlet 26 is provided between the first anode inlet 21 and the anode end plate flow channel region 25, and the first strip-shaped water outlet 27 is provided between the first anode outlet 23 and the anode end plate flow channel region 25. The water flow of the anode end plate is introduced from the first anode inlet 21 on the outer side of the anode end plate 2. The water flow is turned over through the first strip-shaped water inlet 26 thereon and then flows into the anode end plate flow channel region 25 on the inner side thereof to carry out the oxygen evolution reaction on the anode side. After the reaction, the water flow is turned over through the first strip-shaped water outlet 27 to the first anode outlet 23 on the outer side of the anode end plate 2, and then flows out through the anode end plate.

[0043] Specifically, the cathode end plate 3 is further provided with a second strip-shaped water inlet 36 and a second strip-shaped water outlet 37. The second strip-shaped water inlet 36 is provided between the first cathode inlet 31 and the cathode end plate flow channel region 35, and the second strip-shaped water outlet 37 is provided between the first cathode outlet 33 and the cathode end plate flow channel region 35. Water from the cathode end plate is introduced from the first cathode inlet 31 on the outer side of the cathode end plate 3. The water flows through the second strip-shaped water inlet 36 thereon and then flows into the cathode end plate flow channel region 35 on the inner side thereof for hydrogen evolution reaction on the cathode side. After the reaction, the water flows through the second strip-shaped water outlet 37 and flows out through the outlet through-hole 14 of the cathode end plate.

[0044] Specifically, if Figure 4 From the structural schematic diagram of the anode end plate shown, it can be seen that on the outer surface of the anode end plate 2, a bridge flow channel is provided between the first anode inlet 21 and the first strip water inlet 26, and between the first anode outlet 23 and the first strip water outlet 27. The bridge flow channel is formed by strip ridges arranged at intervals, and the strip ridges are arranged radially. Similarly, on the outer surface of the cathode end plate 3, a bridge flow channel is also provided between the first cathode inlet 31 and the second strip water inlet 36, and between the first cathode outlet 33 and the second strip water outlet 37. The bridge flow channel is formed by strip ridges arranged at intervals, and the strip ridges are arranged radially. The setting of the bridge flow channel facilitates the diversion or convergence of the fluid.

[0045] Preferably, if Figure 7 、 8As can be seen from the overall structural view and exploded view of the bipolar plate structure shown, the bipolar plate structure 4 includes a cathode titanium felt 41, a cathode titanium mesh 42, a pole plate 43, an anode titanium mesh 44, and an anode titanium felt 45. The cathode titanium felt 41, cathode titanium mesh 42, pole plate 43, anode titanium mesh 44, and anode titanium felt 45 are stacked in sequence and welded to form an integrated bipolar plate. The outer surface of the integrated bipolar plate is then platinum-plated using a coating process, wherein the welding process uses filler-free diffusion welding and high-temperature sintering, and the coating uses PVD surface coating. The bipolar plate structure 4 adopts an integrated structural design, that is, the integration of various components into one. This not only further reduces the number of components of the PEM electrolyzer of the present application, but also greatly simplifies the subsequent stacking work, reduces the number of coatings, achieves a significant cost reduction, reduces the contact resistance between the various components, and improves the performance of the entire cell.

[0046] Specifically, if Figure 9 、 10 As shown in the schematic diagram of the two side structures of the electrode plate, the electrode plate 43 includes two oppositely disposed side surfaces. The middle portions of the two side surfaces of the electrode plate 43 are etched to form an anode flow channel region and a cathode flow channel region, respectively. The flow channel arrangement directions of the cathode flow channel region and the anode flow channel region of the electrode plate 43 are perpendicular to each other. The anode flow channel region and the cathode flow channel region of the electrode plate 43 are both serpentine flow channels. The serpentine flow channels can extend the fluid residence time and are suitable for high flow rate applications. In the present invention, the electrode plate 43 is square and can be made of titanium plate or stainless steel plate. The flow channel regions on both sides can be processed using an etching process.

[0047] Preferably, if Figure 9 As can be seen from the single-sided side view of the electrode plate shown, the electrode plate 43 is provided with eight water inlets and outlets, which are evenly distributed in pairs around the circumference of the electrode plate 43. The water inlets and outlets include two anode inlets 431, two anode outlets 432, two cathode inlets 433, and two cathode outlets 434. The two anode inlets 431 are connected to the first anode inlet 21 or the second anode inlet 22 of the anode terminal plate 2, the two anode outlets 432 are connected to the first anode outlet 23 or the second anode outlet 24 of the anode terminal plate 2, the two cathode inlets 433 are connected to the first cathode inlet 31 or the second cathode inlet 32 of the cathode terminal plate 2, and the two cathode outlets 434 are connected to the first cathode outlet 33 or the second cathode outlet 34 of the cathode terminal plate 3.

[0048] Specifically, two anode inlets 431 are provided at the upper left end and the left side of the lower portion of the electrode plate 43, two anode outlets 432 are provided at the lower right end and the right side of the upper end of the electrode plate 43, two cathode inlets 433 are provided at the lower left end and the left side of the upper end of the electrode plate 43, and two cathode outlets 434 are provided at the upper right end and the right side of the lower end of the electrode plate 43. In the present application, the inlets and outlets on the electrode plate 43 are of the same size and symmetrically arranged, and all are circular through-holes. Other shapes such as strips or squares may also be used. At the same time, one inlet and outlet are provided for each electrode plate, or a plurality of inlets and outlets may be arranged at intervals.

[0049] Preferably, the electrode plate 43 is provided with a through-fold opening, through which water is turned from one side of the electrode plate to the flow channel area on the other side of the electrode plate, or water is turned from the flow channel area on one side of the electrode plate to the water outlet on the other side of the electrode plate. The flow channel fold opening is strip-shaped and includes a first fold opening 435, a second fold opening 436, a third fold opening 437, and a fourth fold opening 438. The first fold opening 435 is located between the anode inlet 431 at the bottom of the electrode plate and the anode flow channel area, the second fold opening 436 is located between the anode outlet 432 at the top of the electrode plate 43 and the anode flow channel area, the third fold opening 437 is located between the cathode inlet 433 on the right side of the electrode plate 43 and the anode flow channel area, and the fourth fold opening 438 is located between the cathode outlet 434 on the left side of the electrode plate 43 and the anode flow channel area. By setting the flow channel folding opening, the fluid can be folded from one side surface of the electrode plate 43 to the other side surface through the flow channel folding opening.

[0050] Preferably, if Figure 1 As can be seen from the exploded view of the overall structure of the PEM electrolyzer shown, an insulating plate 6 is still provided between the anode end plate and the anode end plate 2, and another insulating plate 6 is provided between the cathode end plate and the cathode end plate 3. The two insulating plates 6 are respectively provided with two water inlets 61 corresponding to the two ends of the water inlet diversion channel 11 of the anode end plate and the cathode end plate, and the two insulating plates 6 are also respectively provided with two water outlets 62 corresponding to the two ends of the water outlet diversion channel 12 of the anode end plate and the cathode end plate.

[0051] Preferably, a first sealing structure of the same structure is provided between the anode end plate and the insulating plate 6, and between the cathode end plate and the insulating plate 6. The first sealing structure includes a sealant groove 15 provided on the anode end plate and the cathode end plate, respectively, and a corresponding sealant is provided inside the sealant groove 15. For the anode end plate, the sealant groove 15 is provided on the periphery of the inlet branch flow channel 11 and the outlet branch flow channel 12 of the anode end plate. The sealant groove 15 and the corresponding sealant are provided to separate the anode end plate side into two inlet chambers and an outlet chamber. For the cathode end plate, the sealant groove 15 is provided on the periphery of the inlet branch flow channel 11 and the outlet branch flow channel 12 of the cathode end plate. The sealant groove 15 and the corresponding sealant are provided to separate the cathode end plate side into an inlet chamber and an outlet chamber.

[0052] Preferably, a symmetrically arranged second sealing structure is provided on each side of the anode terminal plate 2 and the cathode terminal plate 3. The second sealing structure includes sealing grooves provided around the circumference of the plate and around each inlet and outlet, with corresponding sealing lines provided inside the sealing grooves. A symmetrically arranged third sealing structure is provided on each side of the bipolar plate assembly. The third sealing structure includes sealing grooves provided around the circumference of the bipolar plate assembly and around each inlet and outlet, with corresponding sealing lines provided inside the sealing grooves. The provision of the second and third sealing structures ensures that the sealing lines on both sides of the membrane electrode are fully aligned, minimizing sealing failures caused by the structure and ensuring the sealing effect achieved after the components of the PEM electrolyzer of the present application are stacked.

[0053] Specifically, the anode end plate, insulating plate, anode end plate 2, membrane electrode 5, bipolar plate structure 4, cathode end plate 3, and cathode end plate of the PEM electrolyzer constituting this application are each provided with corresponding fixing holes 7, and the fixing holes 7 of each component are fixedly connected by using fixing parts (such as a combination of bolts and nuts).

[0054] Specifically, the number of bipolar plate structures 4 can be stacked more to meet the needs of the electrolysis reaction. When stacking, multiple bipolar plate structures 4 are stacked between the anode end plate 2 and the cathode end plate 3, and a membrane electrode 5 is placed between two adjacent bipolar plate structures 4. After the two adjacent bipolar plate structures 4 are symmetrically placed relative to the membrane electrode 4, one bipolar plate structure 4 is rotated 180 degrees relative to the other bipolar plate structure 4 to form more electrolysis chambers. The bipolar plate structure 4 of the present invention is square, and the sealing structures, inlets and outlets on both sides are symmetrically arranged. Therefore, the anode flow channel area and the cathode flow channel area on both sides of the bipolar plate structure 4 can be used interchangeably according to the layout to meet the requirements of the present application for the separate arrangement of the anode side water inlet and outlet channels and the cathode side water inlet and outlet channels.

[0055] The flow principle of the anode side water inlet and outlet channels and the cathode side water inlet and outlet channels of the PEM electrolyzer of the present invention is as follows: Figure 11As shown in the schematic diagram of the water inlet flow channel of the plate assembly, it can be seen that the solid arrows indicate the direction of fluid flow on the front of each plate, and the hollow arrows indicate the direction of fluid flow on the back of each plate. For the convenience of describing the following principles, the plate assemblies are named 1# plate, 2# plate, 3# plate and 4# plate in the order of stacking. The two anode inlets 431 on the bipolar plate structure located between the anode end plate and the cathode end plate are defined as anode inlet a and anode inlet b, respectively. The two anode outlets 4231 are defined as anode outlet c and anode outlet d, respectively. The two cathode inlets 433 are defined as cathode inlet a' and cathode inlet b', respectively. The two cathode outlets 434 are defined as cathode outlet c' and cathode outlet d', respectively. At the same time, the membrane electrode 5 is transparently treated. Taking the anode side water inlet channel as an example, after the anode side water flows in from the inlet through-hole 13 of the anode end plate, it is split into two water inlets through the inlet diversion channel 11. One water inlet enters from the first anode inlet 21 of the 1# plate and then turns over to the inside of the anode end plate flow channel area 25 to carry out the anode side oxygen evolution reaction. The reacted fluid flows out from the first anode outlet 23. At the same time, the water inlet flows into the anode inlet b of the 2# plate and flows into the anode inlet b of the 3# plate through the anode inlet b of the 2# plate. The water inlet turns over and flows into the anode reaction of the 3# plate. The oxygen evolution reaction is carried out in the anode inlet d of the 3# plate; the second-way water inlet flows into the anode inlet a of the 2# plate through the second anode inlet 22 of the 1# plate, flips into the anode flow channel area on the back of the 2# plate for oxygen evolution reaction, and the fluid after the reaction flows out from the anode outlet c of the 2# plate; the second-way water inlet then flows into the anode inlet a of the 4# plate through the anode inlet a of the 3# plate, flips into the anode flow channel area on the back of the 4# plate for oxygen evolution reaction, and the fluid after the reaction flows out from the anode outlet c of the 4# plate. The above is the principle of the anode side water inlet channel. It can be seen that the reaction zone fluids on the two plates arranged at intervals, such as 1# and 3#, 2# and 4#, have the same flow direction. The cathode side water inlet channel, the anode side water outlet channel, and the cathode side water outlet channel use similar principles to realize different channels, which will not be repeated here. Since the electrode assemblies are each provided with a flipping mouth, the fluid can be flipped and circulated according to different electrolysis reaction requirements after entering from the mouth, and anode side water inlet and outlet channels and cathode side water inlet and outlet channels can be formed on each electrode plate from the end plates on both sides to the electrode plate assembly, thereby meeting the water inlet and outlet requirements on both sides in this application.

Claims

1. A PEM electrolyzer, characterized in that: It includes, The end plate assembly includes two anode end plates and cathode end plates of the same structure provided on both sides, wherein the inner sides of the anode end plates and the cathode end plates are respectively provided with an inlet diversion flow channel and an outlet diversion flow channel, and the outer sides of the anode end plates and the cathode end plates are respectively provided with an inlet through-hole and an outlet through-hole corresponding to the inlet diversion flow channel and the outlet diversion flow channel; A plate assembly comprising an anode end plate, a cathode end plate, and at least one bipolar plate structure, wherein the anode end plate and the cathode end plate are disposed between the anode end plate and the cathode end plate, and the bipolar plate structure is disposed between the anode end plate and the cathode end plate; A membrane electrode, wherein the membrane electrode is spaced between two adjacent plates of the plate assembly, the membrane electrode and the plate assembly forming an electrolysis chamber, and the electrolysis chamber comprises at least an anode reaction chamber and a cathode reaction chamber; The electrode plate assembly and the membrane electrode are provided with an anode side water inlet channel respectively connected to the two ends of the inlet diversion channel of the anode end plate, and the electrode plate assembly and the membrane electrode are provided with an anode side water outlet channel respectively connected to the two ends of the outlet diversion channel of the anode end plate; the electrode plate assembly and the membrane electrode are provided with a cathode side water inlet channel respectively connected to the two ends of the inlet diversion channel of the cathode end plate, and the electrode plate assembly and the membrane electrode are provided with a cathode side water outlet channel respectively connected to the two ends of the outlet diversion channel of the cathode end plate.

2. A PEM electrolyzer according to claim 1, characterized in that: A first anode inlet, a second anode inlet, a first anode outlet and a second anode outlet are respectively provided near the edge of the anode end plate, the first anode inlet and the second anode inlet are connected to the two ends of the inlet shunt flow channel of the anode end plate, and the first anode outlet and the second anode outlet are connected to the two ends of the outlet shunt flow channel of the anode end plate; a first cathode inlet, a second cathode inlet, a first cathode outlet and a second cathode outlet are respectively provided near the edge of the cathode end plate, the first cathode inlet and the second cathode inlet are connected to the two ends of the inlet shunt flow channel of the cathode end plate, and the first cathode outlet and the second cathode outlet are connected to the two ends of the outlet shunt flow channel of the cathode end plate.

3. A PEM electrolyzer according to claim 1, characterized in that: The bipolar plate structure includes a cathode titanium felt, a cathode titanium mesh, a polar plate, an anode titanium mesh, and an anode titanium felt. The polar plate includes two opposite side surfaces. One side surface of the polar plate is etched to form an anode flow channel area, and the other side surface of the polar plate is etched to form a cathode flow channel area. The cathode titanium felt, cathode titanium mesh, polar plate, anode titanium mesh, and anode titanium felt are stacked in sequence and welded to form an integrated bipolar plate.

4. A PEM electrolyzer according to claim 3, characterized in that: The flow channel arrangement directions of the cathode flow channel region and the anode flow channel region of the electrode plate are perpendicular to each other, and both the anode flow channel region and the cathode flow channel region of the electrode plate are serpentine flow channels.

5. A PEM electrolyzer according to claim 4, characterized in that: The electrode plate is provided with a water inlet and outlet, and the water inlet and outlet include 8 and are evenly arranged at the circumferential position of the electrode plate. The water inlet and outlet include two anode inlets, two anode outlets, two cathode inlets, and two cathode outlets. The two anode inlets are connected to the first anode inlet or the second anode inlet of the anode terminal plate, the two anode outlets are connected to the first anode outlet or the second anode outlet of the anode terminal plate, the two cathode inlets are connected to the first cathode inlet or the second cathode inlet of the cathode terminal plate, and the two cathode outlets are connected to the first cathode outlet or the second cathode outlet of the cathode terminal plate.

6. A PEM electrolyzer according to claim 5, characterized in that: The two anode inlets are arranged at the upper left end of the electrode plate and the left side of its lower part, the two anode outlets are arranged at the lower right end of the electrode plate and the right side of its upper end, the two cathode inlets are arranged at the lower left end of the electrode plate and the left side of its upper end, and the two cathode outlets are arranged at the upper right end of the electrode plate and the right side of its lower end.

7. A PEM electrolyzer according to claim 6, characterized in that: The electrode plate is provided with a through flow channel folding mouth, and the flow channel folding mouth is in a strip shape. The flow channel folding mouth includes a first flow channel folding mouth, a second flow channel folding mouth, a third flow channel folding mouth, and a fourth flow channel folding mouth. The first flow channel folding mouth is provided between the anode inlet at the lower part of the electrode plate and the anode flow channel area, the second folding mouth is provided between the anode outlet and the anode flow channel area at the upper part of the electrode plate, the third folding mouth is provided between the cathode inlet and the anode flow channel area on the right side of the electrode plate, and the fourth folding mouth is provided between the cathode outlet and the anode flow channel area on the left side of the electrode plate.

8. A PEM electrolyzer according to claim 7, characterized in that: The cathode terminal plate and the anode terminal plate serve as two-pole current collecting plates.

9. A PEM electrolyzer according to any one of claims 1 to 8, characterized in that: An insulating plate is provided between the anode end plates, and an insulating plate is provided between the cathode end plates. Two water inlets and two water outlets are respectively provided on the two insulating plates. The two water inlets correspond to the two ends of the water inlet diversion channel respectively, and the two water outlets correspond to the two ends of the water outlet diversion channel respectively.

10. A PEM electrolyzer according to claim 9, characterized in that: A first sealing structure is provided between the anode end plate and the insulating plate, and between the cathode end plate and the insulating plate; a symmetrically arranged second sealing structure is provided on both sides of the anode end plate and the cathode end plate; and a symmetrically arranged third sealing structure is provided on both sides of the bipolar plate assembly.

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