Water electrolyser

Abstract

The utility model discloses a water electrolyser which comprises a bipolar plate assembly, a fastening assembly and a clamping piece, the fastening assembly is arranged at the top end of the bipolar plate assembly, the fastening assembly comprises an adjusting bolt and a fixing plate, the fixing plate is arranged at the top end of the bipolar plate assembly, and the adjusting bolt is in threaded connection with the fixing plate; the number of the clamping pieces is at least two, the at least two clamping pieces are arranged in the circumferential direction of the bipolar plate assembly, each clamping piece comprises a first clamping part and a second clamping part, the first clamping parts are connected with the bottom end of the bipolar plate assembly, and the second clamping parts abut against the top end of the fixing plate. The structure is simple, the assembling time of the water electrolyser can be greatly shortened, the assembling efficiency can be improved, the membrane electrode, the porous transmission layer and the bipolar plate assembly can make contact more tightly, then the internal resistance is reduced, and the electrolysis performance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of hydrogen energy, and particularly relates to a water electrolysis cell. Background Art

[0002] A water electrolysis cell is an energy conversion device that consumes water and electric energy to produce hydrogen and oxygen. Its structure mainly includes a membrane electrode assembly (MEA), a porous transport layer (PTL), a bipolar plate, a current collector plate, an insulating plate, an end plate, etc. The MEA includes an anode catalyst layer, a proton exchange membrane (PEM), and a cathode catalyst layer.

[0003] Currently, the assembly of water electrolysis cells usually uses screws and nuts for fastening, or metal straps for clamping. Both of these methods require applying fastening forces at multiple positions around the end plate. Moreover, there are many components and fasteners in the water electrolysis cell, resulting in complex assembly and low efficiency. Summary of the Utility Model

[0004] Based on this, it is necessary to provide a water electrolysis cell with a simple structure, easy to assemble, and capable of improving the assembly efficiency.

[0005] A water electrolysis cell includes:

[0006] A bipolar plate assembly;

[0007] A fastening assembly disposed at the top of the bipolar plate assembly. The fastening assembly includes an adjusting bolt and a fixing plate. The fixing plate is disposed at the top of the bipolar plate assembly. The adjusting bolt is threadedly connected to the fixing plate. The adjusting bolt is used to abut against the bipolar plate assembly and apply pressure to the bipolar plate assembly.

[0008] A clamping member. The number of the clamping members is at least two. At least two clamping members are circumferentially disposed around the bipolar plate assembly. The clamping member includes a first clamping portion and a second clamping portion. The first clamping portion is connected to the bottom end of the bipolar plate assembly. The second clamping portion abuts against the top end of the fixing plate to fix the fixing plate relative to the bipolar plate assembly.

[0009] Optionally, the clamping member further includes a hinge shaft. The first clamping portion and the second clamping portion are hinged by the hinge shaft. The second clamping portion can rotate relative to the first clamping portion to make the second clamping portion approach and abut against the top end of the fixing plate or move away from the top end of the fixing plate, so as to realize the clamping and fixing or loosening between the clamping member and the bipolar plate assembly and the fixing plate.

[0010] Optionally, the second clamping portion includes a connecting section and a clamping section. One end of the connecting section is connected to the clamping section. The other end of the connecting section is hinged to one end of the first clamping portion. The clamping section is perpendicular to the connecting section and extends towards the fixing plate.

[0011] Optionally, the bipolar plate assembly includes a first bipolar plate and a second bipolar plate. The second bipolar plate is disposed at the top of the first bipolar plate, and the first clamping portion is connected to the bottom end of the first bipolar plate.

[0012] Optionally, the bipolar plate assembly further includes a boss. The boss is disposed at the top of the second bipolar plate, and the fixing plate is disposed at the top of the boss. A first threaded hole is formed inside the boss for rotatably connecting with the adjusting bolt.

[0013] Optionally, the first bipolar plate and the second bipolar plate each have two quick connectors.

[0014] Optionally, the first bipolar plate and the second bipolar plate are both provided with flow fields.

[0015] Optionally, the first bipolar plate and the second bipolar plate are both provided with sealing grooves, and the sealing grooves are arranged around the flow fields.

[0016] Optionally, the water electrolysis cell further includes a pressure gauge, and the pressure gauge is disposed at the bottom end of the bipolar plate assembly.

[0017] Optionally, the central axis of the fixing plate coincides with the central axis of the bipolar plate assembly. A second threaded hole is formed in the middle of the fixing plate, and the adjusting bolt passes through the second threaded hole.

[0018] The present application provides a water electrolysis cell. When in use, at least two clamping members are oppositely disposed on both sides of the bipolar plate assembly to fix the fixing plate and the bipolar plate assembly. Then, by rotating the adjusting bolt to apply pressure to the bipolar plate assembly, the membrane electrode and the porous transport layer inside can be made to be in close contact with the bipolar plate assembly respectively, thereby reducing the internal resistance of the water electrolysis cell. Therefore, the structure of the present application is simple, which can greatly shorten the assembly time of the water electrolysis cell, improve the assembly efficiency, and make the contact between the membrane electrode, the porous transport layer and the bipolar plate assembly closer, thereby reducing the internal resistance and enhancing the electrolysis performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0020] Figure 1 It is a schematic structural diagram of a water electrolysis cell in an embodiment;

[0021] Figure 2 It is a schematic exploded view of a water electrolyzer in an embodiment;

[0022] Figure 3 It is a schematic structural view of a clamping member in an embodiment;

[0023] Figure 4 It is a schematic structural view of a first electrode plate in an embodiment.

[0024] 1. Bipolar plate assembly; 11. First electrode plate; 12. Second electrode plate; 13. Boss; 14. Quick connector; 15. Flow field; 16. Sealing groove; 2. Fastening assembly; 21. Adjusting bolt; 211. Knob; 212. Screw rod; 22. Fixed plate; 3. Clamping member; 31. First clamping part; 32. Second clamping part; 321. Connection section; 322. Clamping section; 33. Hinge shaft; 4. Pressure gauge.

[0025] The realization, functional features and advantages of the purpose of the present utility model will be further described with reference to the embodiments and the accompanying drawings. Specific embodiments

[0026] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0027] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0028] In addition, the descriptions involving "first", "second", etc. in the present utility model are only for descriptive purposes, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, "and / or" throughout the text includes three solutions. Taking A and / or B as an example, it includes the technical solution of A, the technical solution of B, and the technical solution that both A and B are satisfied. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0029] Reference Figures 1-3 Figures 1-3 , the present application provides a water electrolysis cell, which includes a bipolar plate assembly 1, a fastening assembly 2, and a clamping member 3. The interior of the bipolar plate assembly 1 is used to place a membrane electrode and a porous transport layer. The fastening assembly 2 is disposed at the top of the bipolar plate assembly 1. The fastening assembly 2 includes an adjusting bolt 21 and a fixing plate 22. The fixing plate 22 is disposed at the top of the bipolar plate assembly 1. The adjusting bolt 21 is threadedly connected to the fixing plate 22. The adjusting bolt 21 is used to abut against the bipolar plate assembly 1 and apply pressure to the bipolar plate assembly 1; the number of the clamping members 3 is at least two. The clamping members 3 are arranged circumferentially around the bipolar plate assembly 1. The clamping member 3 includes a first clamping portion 31 and a second clamping portion 32. The first clamping portion 31 is connected to the bottom end of the bipolar plate assembly 1. The second clamping portion 32 abuts against the top end of the fixing plate 22, and the bipolar plate assembly 1 and the fixing plate are clamped between the first clamping portion 31 and the second clamping portion 32, thereby realizing the fixation of the fixing plate 22 relative to the bipolar plate assembly 1.

[0030] The present application provides a water electrolysis cell. During use, by respectively arranging a plurality of clamping members 3 circumferentially around the bipolar plate assembly 1 and realizing the fixation between the fixing plate 22 and the bipolar plate assembly 1, and then by rotating the adjusting bolt 21 to apply pressure to the bipolar plate assembly 1, the membrane electrode and the porous transport layer inside can be made to be in close contact with the bipolar plate assembly 1 respectively, thereby reducing the internal resistance of the water electrolysis cell. Therefore, the structure of the present application is simple, which can greatly shorten the assembly time of the water electrolysis cell, improve the assembly efficiency, and make the contact between the membrane electrode, the porous transport layer and the bipolar plate assembly 1 closer, thereby reducing the internal resistance and improving the electrolysis performance.

[0031] Specifically, the adjusting bolt 21 includes a knob 211 and a screw 212. The knob 211 is disposed above the screw 212. By rotating the knob 211, the screw 212 is driven to rotate and move in a direction close to or away from the bipolar plate assembly 1.

[0032] Specifically, the clamping members 3 are evenly spaced along the circumferential direction of the bipolar plate assembly 1. When there are two clamping members 3, the two clamping members 3 are arranged oppositely. When there are three clamping members 3, they are arranged at intervals of 120 degrees along the circumferential direction of the bipolar plate assembly 1; in other embodiments, the plurality of clamping members are unevenly spaced along the circumferential direction of the bipolar plate assembly.

[0033] Specifically, both the bipolar plate assembly 1 and the fixing plate 22 are plate-like structures and have the same length and width dimensions. In this embodiment, the number of the clamping members 3 is four. The four clamping members 3 are respectively disposed in the middle of the four sides of the bipolar plate assembly 1, and two of the clamping members 3 are arranged oppositely, and the other two clamping members 3 are arranged oppositely.

[0034] In this embodiment, the clamping member 3 is made of a rigid material to increase the fastening force. In other embodiments, the clamping member 3 can also be made of an elastic material.

[0035] Referring to Figure 3 , the clamping member 3 further includes a hinge shaft 33. The first clamping portion 31 and the second clamping portion 32 are hinged by the hinge shaft 33. The second clamping portion 32 can rotate relative to the first clamping portion 31 so that the second clamping portion 32 approaches and abuts against the top end of the fixing plate 22 or moves away from the top end of the fixing plate 22, thereby realizing the clamping and fixing or loosening between the clamping member 3 of the bipolar plate assembly 1 and the fixing plate 22.

[0036] Referring to Figure 2 and Figure 3 , the second clamping portion 32 includes a connecting section 321 and a clamping section 322. One end of the connecting section 321 is connected to the clamping section 322, and the other end of the connecting section 321 is hinged to one end of the first clamping portion 31. The clamping section 322 is perpendicular to the connecting section 321 and extends toward the fixing plate 22. When the clamping section 322 abuts against the top end of the fixing plate 22, it is parallel to the first clamping portion 31. Thus, the first clamping portion 31, the connecting section 321, and the clamping section 322 form a substantially C shape. When the clamping member 3 clamps and fixes the fixing plate 22 and the bipolar plate assembly 1, in this embodiment, the connecting section 321 abuts against the side surfaces of the bipolar plate assembly 1 and the fixing plate 22 respectively, and the clamping section 322 abuts against the top end of the fixing plate 22. In other embodiments, the connecting section 321 may not abut against the side surfaces of the bipolar plate assembly 1 and the fixing plate 22.

[0037] Specifically, a first hinge hole is provided at the other end of the connecting section 321, and a second hinge hole is provided at one end of the first clamping portion 31. The hinge shaft 33 passes through the first hinge hole and the second hinge hole.

[0038] Referring to Figure 1 and Figure 4 , the bipolar plate assembly 1 includes a first plate 11 and a second plate 12. The second plate 12 is disposed at the top end of the first plate 11. One end of the first clamping portion 31 away from the connecting section 321 is fixedly provided at the bottom end of the first plate 11 by screws.

[0039] Specifically, the first plate 11 and the second plate 12 have the same size. During use, the second clamping portion 32 is buckled on the fixing plate 22 to quickly fix the second plate 12 and the fixing plate 22, facilitating the adjustment of the pressure applied by the bolt 21. When disassembly is required, the second clamping portion 32 is released, and the fixing plate 22 and the second plate 12 can be quickly disassembled, greatly improving the efficiency.

[0040] In this embodiment, the first plate 11 is an anode plate, and the second plate 12 is a cathode plate.

[0041] Referring to Figure 1, the bipolar plate assembly 1 further includes a boss 13. The boss 13 is provided at the top end of the second bipolar plate 12. The fixing plate 22 is provided at the top end of the boss 13. A first threaded hole is formed inside the boss 13 for rotatably connecting with the adjusting bolt 21.

[0042] Specifically, the boss 13 is provided in the middle of the second bipolar plate 12.

[0043] Reference Figure 1 , the first bipolar plate 11 and the second bipolar plate 12 each have two quick connectors 14. The two quick connectors 14 are provided on opposite sides of the first bipolar plate 11 or the second bipolar plate 12. One of the quick connectors 14 on the first bipolar plate 11 is used to communicate with the water inlet of the electrolytic water test bench, and the other is used to communicate with the oxygen discharge port of the electrolytic water test bench. One of the quick connectors 14 on the second bipolar plate 12 is used to communicate with the hydrogen discharge port of the electrolytic water test bench, and the tabs of the first bipolar plate 11 and the second bipolar plate 12 are connected to the current line and voltage line of the current source. By controlling the current source to output current through the computer, the water electrolysis cell can work normally.

[0044] Reference Figure 4 , the first bipolar plate 11 and the second bipolar plate 12 are both provided with a flow field 15. The two quick connectors 14 are both in communication with the flow field 15. Specifically, the flow field 15 adopts a multi-snake-shaped flow channel, which can ensure that the travel of the reactants in the active area of the membrane electrode is long enough, extend the residence time of the reactants, and has good water and gas transmission capabilities, and the pressure drop at the inlet and outlet is moderate. And the flow fields 15 of the first bipolar plate 11 and the second bipolar plate 12 are mirror-symmetrical.

[0045] The first bipolar plate 11 and the second bipolar plate 12 are both provided with a sealing groove 16. The sealing groove 16 is arranged around the flow field 15. The bipolar plate assembly 1 further includes a sealing gasket. The sealing gasket is arranged in the sealing groove 16. By adjusting the thickness and tightening force of the sealing gasket, the compression ratio of the PTL is controlled, and the sealing performance of the water electrolysis cell is ensured, so that the membrane electrode is in close contact with the PTL, and the internal resistance of the water electrolysis cell is reduced.

[0046] In this embodiment, one of the quick connectors 14 on the first bipolar plate 11 is used for the entry of reaction water. The reaction water enters the flow field 15 of the first bipolar plate 11 and then is evenly distributed to the anode catalyst layer, where an electron loss reaction occurs to produce H+ and O2. Among them, O2 is discharged from the other quick connector 14 of the first bipolar plate 11 along with the anode reaction water, while H+ passes through the proton exchange membrane, reaches the cathode catalyst layer, obtains electrons to generate H2, and is discharged from the quick connector 14 on the second bipolar plate 12 that is in communication with the hydrogen discharge port, realizing high-efficiency conversion of energy, and the whole process is carbon-free and pollution-free.

[0047] Reference Figure 2, the water electrolysis cell further includes a pressure gauge 4, which is arranged at the bottom end of the first electrode plate 11 and can read the pressure received by the MEA in real time, so as to make adjustments and optimizations, and accurately control the assembly process parameters of the electrolysis cell.

[0048] Specifically, by rotating the knob 211 to apply pressure to the second electrode plate 12, observing the reading of the pressure gauge 4, and adjusting the pressure range of the water electrolysis cell to 2.5 - 4.5 MPa to ensure close contact and low internal resistance between the components of the water electrolysis cell.

[0049] Reference Figure 2 , the central axis of the fixing plate 22 coincides with the central axis of the boss 13. A second threaded hole is provided in the middle of the fixing plate 22, and the second threaded hole of the fixing plate 22 communicates with the first threaded hole of the boss 13. The adjusting bolt 21 is inserted into the first threaded hole and the second threaded hole.

[0050] By passing the adjusting screw 212 through the center of the fixing plate 22 and perpendicular to the center of the second electrode plate 12 (i.e., inside the boss 13), and applying a uniformly increasing pressure to the second electrode plate 12 by rotating the adjusting screw 212. Because the force application point of the second electrode plate 12 is at the center, the pressure in the middle area is slightly higher than that in the surrounding areas, and the active area of the MEA is also in the middle position. Compared with the traditional method of tightening the screw 212 around the periphery, this method will cause the end plate to be stressed at the edge area and less stressed in the middle. And the reaction active area of the MEA usually corresponds to the middle area of the end plate, resulting in insufficient close contact between the MEA and the PTL, and a relatively large internal resistance of the electrolysis cell. Applying force to the center of the second electrode plate 12 can better ensure close contact between the MEA, PTL, first electrode plate 11 and second electrode plate 12, and at the same time take into account the sealing performance of the electrolysis cell.

[0051] In the actual production process, the gasket is placed in the sealing groove 16 of the first electrode plate 11 and the second electrode plate 12. The MEA and PTL are sandwiched between the bipolar plate assemblies 1 in a sandwich form, and their order is the second electrode plate 12, PTL, MEA, PTL, first electrode plate 11. The compression ratio of the PTL is controlled by the thickness of the gasket and the assembly pressure of the electrolysis cell to ensure close contact between the PTL and the MEA and the electrode plates, and a relatively low internal resistance of the electrolysis cell.

[0052] In this embodiment, under the working conditions of normal pressure, 60 °C, and a reaction water flow rate of 200 mL / min, using an 80 - um proton exchange membrane, the current density is 3 A / cm2, and the internal resistance of the water electrolysis cell can be as low as 80 mΩ·cm2, and the electrolysis voltage is below 1.8 V.

[0053] The above are only the preferred embodiments of the present utility model, and do not thus limit the patent scope of the present utility model. Any equivalent structural transformation made under the inventive concept of the present utility model by using the content of the specification and drawings of the present utility model, or any direct / indirect application in other related technical fields shall be included within the patent protection scope of the present utility model.

Claims

1. A water electrolyzer, characterized in that: include: Bipolar plate assembly; A fastening assembly, arranged at the top of the bipolar plate assembly, the fastening assembly comprising an adjusting bolt and a fixing plate, the fixing plate being arranged at the top of the bipolar plate assembly, the adjusting bolt being threadedly connected to the fixing plate, and the adjusting bolt being used to abut against the bipolar plate assembly and apply pressure to the bipolar plate assembly; A clamping member, the number of which is at least two, at least two of which are arranged circumferentially around the bipolar plate assembly, the clamping member comprising a first clamping portion and a second clamping portion, the first clamping portion being connected to the bottom end of the bipolar plate assembly, and the second clamping portion being abutted against the top end of the fixed plate to achieve fixation of the fixed plate relative to the bipolar plate assembly.

2. The water electrolyzer according to claim 1, characterized in that: The clamping member also includes a hinge shaft, and the first clamping part and the second clamping part are hinged through the hinge shaft. The second clamping part can rotate relative to the first clamping part so that the second clamping part approaches and abuts against the top end of the fixed plate or moves away from the top end of the fixed plate, thereby achieving the clamping, fixing or loosening of the bipolar plate assembly and the fixed plate by the clamping member.

3. The water electrolyzer according to claim 2, characterized in that: The second clamping portion includes a connecting section and a clamping section, one end of the connecting section is connected to the clamping section, the other end of the connecting section is hinged to one end of the first clamping portion, and the clamping section is perpendicular to the connecting section and extends toward the fixing plate.

4. The water electrolyzer according to claim 1, characterized in that: The bipolar plate assembly includes a first polar plate and a second polar plate, wherein the second polar plate is disposed at a top end of the first polar plate, and the first clamping portion is connected to a bottom end of the first polar plate.

5. The water electrolyzer according to claim 4, characterized in that: The bipolar plate assembly also includes a boss, which is arranged at the top of the second polar plate, and the fixing plate is arranged at the top of the boss. A first threaded hole is opened inside the boss, and the first threaded hole is used for rotationally connecting with the adjusting bolt.

6. The water electrolyzer according to claim 4, characterized in that: The first pole plate and the second pole plate respectively have two quick-connect connectors.

7. The water electrolyzer according to claim 4, characterized in that: The first electrode plate and the second electrode plate are both provided with flow fields.

8. The water electrolyzer according to claim 7, characterized in that: The first electrode plate and the second electrode plate are both provided with sealing grooves, and the sealing grooves are arranged around the flow field.

9. The water electrolyzer according to claim 1, characterized in that: The water electrolyzer also includes a pressure gauge, which is arranged at the bottom end of the bipolar plate assembly.

10. The water electrolyzer according to claim 1, characterized in that: The central axis of the fixing plate coincides with the central axis of the bipolar plate assembly, a second threaded hole is opened in the middle of the fixing plate, and the adjusting bolt is inserted into the second threaded hole.

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