Proton exchange membrane electrolyzed water single-cell clamp

Abstract

The utility model discloses a proton exchange membrane electrolyzed water single-cell clamp, which comprises a membrane electrode, and diffusion layers, a support gasket, a collector plate, an insulation gasket and an end plate which are sequentially arranged on two sides of the membrane electrode, the diffusion layers comprise a cathode diffusion layer and an anode diffusion layer, and the size of the anode diffusion layer is larger than that of the cathode diffusion layer. According to the utility model, the size of the anode diffusion layer is larger than that of the cathode diffusion layer, when the clamp is subjected to high pressure or differential pressure, the size of the anode diffusion layer is larger than that of the cathode diffusion layer, and the edge contact force of the diffusion layer is small, so that the diffusion layer is not easy to puncture a membrane electrode, cause damage to the membrane electrode, even interflow of hydrogen and oxygen, and cause explosion risk.

Description

Technical Field

[0001] This utility model relates to the field of water electrolysis technology, and more specifically to a single-cell fixture for proton exchange membrane water electrolysis. Background Technology

[0002] Hydrogen production through water electrolysis, as a green and environmentally friendly method, is of great significance for energy transition and climate change response. Proton exchange membrane electrolysis (PEMWE) technology is widely considered an ideal technology for large-scale hydrogen production due to its high efficiency, stability, and high output pressure. This technology plays a crucial role in achieving zero-carbon emission hydrogen production.

[0003] Proton exchange membrane high-pressure electrolyzers can achieve internal pressures of 3–5 MPa. They utilize chemical energy to generate pressure differentials, making it easier for ions in the electrolyte to contact the electrodes, thus improving reaction efficiency, significantly increasing electrolysis efficiency, and reducing overall energy consumption and cost. High differential pressure electrolyzers can better adapt to large fluctuations in current, and are generally characterized by high hydrogen pressure and low oxygen pressure. This allows for very low requirements on the anode circulating water unit and gas analysis unit in the electrolyzer testing system, which can operate at atmospheric pressure, greatly saving on the cost of the testing system.

[0004] However, existing proton exchange membrane electrolysis fixtures cannot meet the requirements; the inventors have discovered the following main problems:

[0005] In existing proton exchange membrane electrolysis fixtures, there is no support between the diffusion layer and the flow field, and the diffusion layers of the anode and cathode are the same size. Under high or differential pressure operation, the diffusion layer is typically made of titanium felt on both sides. Therefore, during long-term operation of the electrolyzer under high or differential pressure, the edges of the two titanium felts clamping the membrane electrode experience significant stress. Since titanium felt is generally porous with many sharp points, and the membrane electrode is very thin, it is easily punctured by the titanium felt, causing short circuits and damage to the membrane electrode. In severe cases, this can lead to gas crosstalk and an explosion risk. Utility Model Content

[0006] The technical problem to be solved by this invention is how to prevent the diffusion layer from puncturing the membrane electrode.

[0007] This utility model solves the above-mentioned technical problems through the following technical means: a proton exchange membrane electrolysis water single-cell fixture, including a membrane electrode and a diffusion layer, a support pad, a current collector, an insulating pad, and an end plate arranged sequentially on both sides of the membrane electrode. The diffusion layer includes a cathode diffusion layer and an anode diffusion layer, and the size of the anode diffusion layer is larger than that of the cathode diffusion layer.

[0008] As a preferred technical solution, the projection of the cathode diffusion layer onto the anode diffusion layer is located within the region where the anode diffusion layer is located.

[0009] As a preferred technical solution, the support pad includes a cathode support pad a, a cathode support pad b, an anode support pad a, and an anode support pad b. One end of the cathode support pad a is connected to a current collector, and the other end is connected to the anode support pad b. One end of the cathode support pad b is connected to a current collector, and the other end is connected to the anode support pad a. The other end of the anode support pad b is connected to another current collector, and the anode support pad a is connected to another current collector.

[0010] As a preferred technical solution, the cathode support pad b and the anode support pad a have the same outer diameter, and the inner diameter of the anode support pad a is larger than the inner diameter of the cathode support pad b.

[0011] As a preferred technical solution, the thickness of the cathode support pad a is greater than the thickness of the cathode support pad b, and the thickness of the anode support pad a is greater than the thickness of the anode support pad b.

[0012] As a preferred technical solution, the cathode support pad a, cathode support pad b, anode support pad a, and anode support pad b are all rectangular pads. The cathode support pad a and anode support pad b have the same size, and the cathode support pad b and anode support pad a have smaller sizes than the cathode support pad a or anode support pad b.

[0013] As a preferred technical solution, a sealing ring is also provided between the current collector plate and the insulating gasket, and the sealing ring is embedded in the current collector plate and abuts against the insulating gasket.

[0014] As a preferred technical solution, all the flow collectors are provided with a serpentine flow field.

[0015] As a preferred technical solution, the two current collectors are respectively provided with grooves that are adapted to the cathode support pad a and the anode support pad b.

[0016] As a preferred technical solution, the cathode support pad a and the anode support pad a are made of PTFE, and the cathode support pad b and the anode support pad b are made of silicone.

[0017] The beneficial effects of this utility model are as follows:

[0018] (1) In this utility model, by making the size of the anode diffusion layer larger than that of the cathode diffusion layer, when the fixture is subjected to high pressure or differential pressure, the size of the anode diffusion layer is larger than that of the cathode diffusion layer, and the contact force at the edge of the diffusion layer is smaller, making it less likely to be deformed by pressure, thereby puncturing the membrane electrode, causing damage to the membrane electrode, or even hydrogen and oxygen cross-contamination, causing an explosion risk.

[0019] (2) In this utility model, by using two support pads, the anode support pad and the cathode support pad can support the diffusion layer under high pressure or differential pressure, protect the diffusion layer from deformation, and increase its durability; at the same time, the cathode support pad a and the anode support pad b have different sizes and are subjected to staggered forces, reducing the internal size of the two support pads to jointly squeeze the diffusion layer, avoiding severe deformation of the diffusion layer, puncturing the membrane electrode and causing damage to the membrane electrode, or even hydrogen and oxygen cross-contamination, causing an explosion. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the exploded structure provided for an embodiment of the present utility model;

[0021] Figure 2 A schematic diagram of the cathode current collector structure provided in an embodiment of this utility model;

[0022] Figure 3 A schematic diagram of the anode support pad a structure provided in this embodiment of the utility model;

[0023] Figure 4 A schematic diagram of the anode support pad b structure provided in this embodiment of the utility model;

[0024] Figure 5 A schematic diagram of the cathode support pad b structure provided in this embodiment of the utility model;

[0025] Reference numerals: 1. Cathode end plate; 2. Cathode insulating gasket; 3. Cathode sealing O-ring; 4. Cathode support gasket a; 5. Cathode support gasket b; 6. Cathode current collector; 7. Cathode diffusion layer; 8. Anode diffusion layer; 9. Anode support gasket a; 10. Anode support gasket b; 11. Anode current collector; 12. Voltage acquisition terminal; 13. Anode sealing O-ring; 14. Anode insulating gasket; 15. Anode end plate. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0027] See Figure 1A single-cell fixture for proton exchange membrane electrolysis includes an end plate, an insulating gasket, a supporting gasket, a diffusion layer, and a membrane electrode (not shown). The diffusion layer, supporting gasket, insulating gasket, and end plate are sequentially arranged on both sides of the membrane electrode. In this embodiment, the diffusion layer includes a cathode diffusion layer 7 and an anode diffusion layer 8. The size of the anode diffusion layer 8 is larger than that of the cathode diffusion layer 7. That is, the orthogonal projection of the cathode diffusion layer 7 onto the anode diffusion layer 8 is located within the area where the anode diffusion layer 8 is located. Therefore, under the action of high pressure and pressure difference, the edges of the cathode diffusion layer 7 and the anode diffusion layer 8 are staggered to prevent excessive edge force caused by the cathode diffusion layer 7 and the anode diffusion layer 8 being the same size. Since the diffusion layer is a porous structure, it avoids the edge of the diffusion layer piercing the membrane electrode, causing damage to the membrane electrode, or even hydrogen and oxygen cross-contamination, resulting in an explosion.

[0028] The edges of the cathode diffusion layer 7 and the anode diffusion layer 8 are staggered. Under differential pressure, the anode pressure is higher than the cathode pressure, and the anode diffusion layer 8 will press against the cathode diffusion layer 7. Since the cathode diffusion layer 7 is larger than the anode diffusion layer 8, the edge force is smaller, and the diffusion layer is less stressed, making it less likely to be deformed and puncture the membrane electrode. It should be noted that in the prior art, the two diffusion layers are the same size, and the cathode pressure is greater than the anode pressure.

[0029] See Figure 3 , Figure 4 , Figure 5 The support pads include cathode support pad a4, cathode support pad b5, anode support pad a9, and anode support pad b10. Cathode support pad a4 and anode support pad b10 have the same dimensions, i.e., the same inner and outer diameters, and are rectangular pads. Cathode support pad b5 and anode support pad a9 are also rectangular pads. The dimensions of cathode support pad b5 and anode support pad a9 are smaller than those of cathode support pad a4 or anode support pad b10. That is, the outer diameter of cathode support pad b5 and anode support pad a9 is smaller than the inner diameter of cathode support pad a4 or anode support pad b10. Cathode support pad b5 and anode support pad a9 have the same outer diameter, the inner diameter of anode support pad a9 is larger than the inner diameter of cathode support pad b5, and the area of ​​anode support pad a9 is smaller than the area of ​​cathode support pad b5.

[0030] The deformed portion of the anode support pad, i.e., anode support pad b10, is larger than the deformed portion of the cathode support pad, b5. This allows the anode support pad a9 and cathode support pad b5 to be subjected to staggered forces under high or differential pressure, reducing the area of ​​the diffusion layer that is jointly compressed by the internal dimensions of the two support pads. This results in severe deformation of the diffusion layer, which can cause the diffusion layer to puncture the membrane electrode, damaging the membrane electrode, or even causing hydrogen and oxygen to cross-contaminate and explode.

[0031] Among them, the cathode support pad a4 and the anode support pad a9 are made of PTFE material, which is not easily deformed and can better protect the diffusion layer from squeezing the membrane electrode under high pressure and differential pressure. When the anode force is greater than the cathode force, it plays a supporting and protective role for the diffusion layer. The cathode support pad b5 and the anode support pad b10 are made of silicone material, which has a large deformation and can improve the sealing of the assembly fixture to prevent air and water leakage.

[0032] The cathode support pad a4 and the anode support pad a9 have a thickness of 0.8 to 1.2 mm, and the cathode support pad b5 and the anode support pad b10 have a thickness of 0.4 to 1 mm. Of course, the specific thickness is adjusted according to the thickness of the diffusion layer. In this embodiment, the thickness of the cathode support pad a4 is greater than the thickness of the cathode support pad b5, and the thickness of the anode support pad a9 is greater than the thickness of the anode support pad b10.

[0033] The current collector includes a cathode current collector 6 and an anode current collector 11, which are located on opposite sides of the membrane electrode. The cathode current collector 6 has a groove adapted to the cathode support pad a4, and the anode current collector 11 has a groove adapted to the anode support pad b10. The groove depth is 0.5 to 1 mm. The cathode current collector 6 and the anode current collector 11 also have planes parallel to the flow field and conforming to the dimensions of the cathode support pad b5 and the anode support pad b10.

[0034] By setting up cathode support pad b5 and anode support pad a9, cathode support pad a4 and anode support pad b10, cathode diffusion layer 7 and anode diffusion layer 8, the diffusion layer can effectively contact the membrane electrode and the flow field on both sides, greatly improving the performance of the membrane electrode. It can also provide good support for the diffusion layer under high pressure / differential pressure, preventing it from puncturing the membrane electrode, causing a short circuit, and damaging the membrane electrode.

[0035] See Figure 1 The insulating gasket includes a cathode insulating gasket 2 and an anode insulating gasket 14. The end plate includes a cathode end plate 1 and an anode end plate 15. Both the cathode current collector 6 and the anode current collector 11 are provided with sealing rings. The cathode sealing O-ring 3 is embedded in the cathode current collector 6 and is attached to the cathode insulating gasket 2. The anode sealing O-ring 13 is embedded in one side of the anode current collector 11 and is attached to the anode insulating gasket 14 together with the anode current collector 11.

[0036] The cathode current collector 6 and the anode current collector 11 are made of titanium or titanium alloy. The surfaces of the cathode current collector 6 and the anode current collector 11 are treated with a precious metal coating, which is platinum, iridium, ruthenium or an alloy of some of these metals.

[0037] The membrane electrode does not require a polyester frame for sealing; the catalyst can be directly sprayed onto the membrane, which can increase the contact between the catalytic layer and the diffusion layer, greatly improving the performance of the membrane electrode.

[0038] See Figure 2 The cathode current collector 6 and the anode current collector 11 adopt a serpentine flow field, which can effectively ensure that water flows evenly across each surface of the electrolyzer, promotes full contact between water and the diffusion layer and its penetration into the catalyst layer to participate in the reaction, and increases the active area of ​​the water electrolysis reaction.

[0039] The cathode end plate 1 is on the outermost side. The cathode insulating gasket 2 is attached inward to the inner side of the cathode end plate 1. The cathode sealing O-ring 3 is embedded in the cathode current collector 6 and attached to the cathode insulating gasket 2. The cathode support gasket a4, cathode support gasket b5 and cathode diffusion layer 7 are attached to one side of the cathode current collector 6. The membrane electrode is attached to one side of the cathode support gasket a4, cathode support gasket b5 and cathode diffusion layer 7. The anode support gasket a9, anode support gasket b10 and anode diffusion layer 8 are attached to the other side of the membrane electrode. The voltage acquisition terminal 12 is embedded in one end of the anode current collector 11. The anode current collector 11 is attached to one side of the anode support gasket a9, anode support gasket b10 and anode diffusion layer 8. The anode sealing O-ring 13 is embedded in one side of the anode current collector 11 and is attached to one side of the anode insulating gasket 14 together with the anode current collector 11. The anode end plate 15 is attached to the other side of the anode insulating gasket 14.

[0040] Working principle:

[0041] The cathode side of the membrane electrode is bonded to cathode support pads a4, b5, and 7, and the cathode diffusion layer 7. The other side of cathode support pads a4, b5, and 7 is bonded to the cathode current collector 6. A cathode sealing O-ring 3 is embedded in the cathode current collector 6 and bonded to the cathode insulating pad 2. The other side of the cathode insulating pad 2 is bonded to the cathode end plate 1. The anode side of the membrane electrode is bonded to anode support pads a9, b10, and 8, and the anode diffusion layer 8. The other side of anode support pads a9, b10, and 8 is bonded to the anode current collector 11. An anode sealing O-ring 13 is embedded in the anode current collector 11 and bonded to the anode insulating pad 14. The other side of the sheet 14 is attached to the anode end plate 15. Then, the cathode end plate 1, cathode insulating gasket 2, cathode current collector 6, cathode diffusion layer 7, membrane electrode, anode diffusion layer 8, anode current collector 11, anode insulating gasket 14, and anode end plate 15 on both sides of the membrane electrode are locked and fixed by fastening bolts through the mounting through holes. After locking, the anode diffusion layer 8 and cathode diffusion layer 7 are pressed together and can be tightly attached to the side of the membrane electrode, ensuring close contact between the anode diffusion layer 8 and cathode diffusion layer 7 and the membrane electrode, thereby improving the experimental performance of the membrane electrode. Under high pressure or differential pressure, the cathode diffusion layer 7 is larger than the anode diffusion layer 8, and the contact force at the edge of the diffusion layer is smaller, making it less likely to be deformed by pressure and puncture the membrane electrode.

[0042] The anode support pad a9 and the cathode support pad b5 are subjected to alternating forces, which reduces the internal size of the two support pads and compresses the diffusion layer together. This causes severe deformation of the diffusion layer, which in turn causes the diffusion layer to puncture the membrane electrode, resulting in damage to the membrane electrode and even hydrogen-oxygen cross-contamination, leading to an explosion.

[0043] The above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A single-cell fixture for proton exchange membrane electrolysis of water, characterized in that, It includes a membrane electrode and a diffusion layer, a support pad, a current collector, an insulating pad, and an end plate sequentially disposed on both sides of the membrane electrode. The diffusion layer includes a cathode diffusion layer and an anode diffusion layer, and the anode diffusion layer is larger than the cathode diffusion layer.

2. The proton exchange membrane electrolysis water single-cell fixture according to claim 1, characterized in that, The projection of the cathode diffusion layer onto the anode diffusion layer lies within the region where the anode diffusion layer is located.

3. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 1, characterized in that, The support pads include cathode support pad a, cathode support pad b, anode support pad a, and anode support pad b. One end of cathode support pad a is connected to a current collector, and the other end is connected to anode support pad b. One end of cathode support pad b is connected to a current collector, and the other end is connected to anode support pad a. The other end of anode support pad b is connected to another current collector, and anode support pad a is connected to another current collector.

4. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 3, characterized in that, The cathode support pad b has the same outer diameter as the anode support pad a, and the inner diameter of the anode support pad a is larger than the inner diameter of the cathode support pad b.

5. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 3, characterized in that, The thickness of cathode support pad a is greater than the thickness of cathode support pad b, and the thickness of anode support pad a is greater than the thickness of anode support pad b.

6. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 3, characterized in that, The cathode support pad a, cathode support pad b, anode support pad a, and anode support pad b are all rectangular pads. The cathode support pad a and anode support pad b have the same size, while the cathode support pad b and anode support pad a have smaller size than the cathode support pad a or anode support pad b.

7. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 1, characterized in that, A sealing ring is also provided between the current collector plate and the insulating gasket. The sealing ring is embedded in the current collector plate and abuts against the insulating gasket.

8. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 1, characterized in that, All the flow collectors are equipped with a serpentine flow field.

9. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 3, characterized in that, The two current collectors are respectively provided with grooves that are adapted to the cathode support pad a and the anode support pad b.

10. A single-cell fixture for proton exchange membrane electrolysis of water according to claim 3, characterized in that, The cathode support pad a and anode support pad a are made of PTFE, while the cathode support pad b and anode support pad b are made of silicone.

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