Membrane electrode pinhole detection device and detection method thereof

Abstract

The application relates to a membrane electrode pinhole detection device and a detection method thereof. The membrane electrode pinhole detection device comprises a lamp plate, a connecting device, a Hui-shaped fixing frame, a clamping device, a water source dropper head and a gas source nozzle. One end of the connecting device is connected with the lamp plate. The Hui-shaped fixing frame is connected with one end of the connecting device, and the Hui-shaped fixing frame is detachably installed above the lamp plate through the connecting device. The clamping device is arranged on the Hui-shaped fixing frame, and the clamping device is used for clamping the proton membrane edge of the membrane electrode, so that the membrane electrode is suspended above the lamp plate. The water source dropper head is arranged above the Hui-shaped fixing frame, and the water source dropper head can be moved to be directly above the pinhole of the membrane electrode. The gas source nozzle is located between the lamp plate and the Hui-shaped fixing frame, and the gas source nozzle can be moved to be directly below the pinhole of the membrane electrode. The device has the advantages of simple structure, low cost, simple and reliable operation method and short test time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fuel cells, in particular to a membrane electrode pinhole detection device and a detection method thereof. BACKGROUND

[0002] Proton exchange membrane (PEM) water electrolysis hydrogen production technology is considered one of the core technologies for green hydrogen production due to its fast start-stop characteristics and high adaptability to renewable energy generation fluctuations. In the PEM electrolyzer, the membrane electrode, as the core carrier of the electrochemical reaction, is composed of anode and cathode catalyst layers coated on both sides of the proton membrane, and directly determines the efficiency and stability of water electrolysis hydrogen production.

[0003] However, during the preparation of the membrane electrode, two types of pinhole defects, non-penetrating pinholes and penetrating pinholes, are easily generated in the active area (catalyst layer area). Non-penetrating pinholes are mainly caused by catalyst layer material defects or coating process deviations, resulting in local non-coated proton membranes. Such pinholes have no substantial impact on the performance of the membrane electrode. However, penetrating pinholes (perforations) are caused by mechanical damage or process out-of-control during production, resulting in complete penetration of the proton membrane. Such defects will cause serious consequences, such as mixing of reaction gases (hydrogen / oxygen) across the membrane, reducing electrolysis efficiency and increasing energy consumption; hydrogen and oxygen mixing leading to explosion risk; accelerating membrane electrode corrosion, shortening equipment life and increasing maintenance costs.

[0004] Currently, the detection of penetrating pinholes in the industry mainly relies on traditional air tightness testing methods, i.e., pressurized detection of gas leakage after the membrane electrode is installed in the electrolyzer. This method has significant defects:

[0005] Complicated operation: requires complete assembly of the electrolyzer, which takes up to several hours;

[0006] High pressure damage risk: the high pressure environment during testing can cause irreversible damage to the membrane electrode;

[0007] Cannot locate defects: only determines the presence of leakage, cannot accurately identify the location and nature (penetrating or non-penetrating) of the pinhole.

[0008] Therefore, it is urgent to develop a simple, efficient, non-destructive and accurate detection method and device for penetrating pinholes to improve the reliability of membrane electrode quality control and reduce the manufacturing and maintenance costs of PEM electrolyzers. SUMMARY

[0009] Therefore, it is necessary to provide a membrane electrode pinhole detection device and a detection method thereof to solve the technical problems in the prior art.

[0010] To achieve the above-mentioned purposes, the present application provides a technical solution:

[0011] A membrane electrode pinhole detection device, comprising:

[0012] a lamp plate;

[0013] a connecting device, one end of which is connected to the lamp plate;

[0014] a U-shaped fixing frame, one end of which is connected to the connecting device, and which is detachably mounted above the lamp plate through the connecting device;

[0015] a clamping device, which is arranged on the U-shaped fixing frame and used for clamping the proton membrane edge of the membrane electrode, so that the membrane electrode is suspended above the lamp plate;

[0016] a water source dropper head, which is arranged above the U-shaped fixing frame and is movable to the position directly above the pinhole of the membrane electrode;

[0017] a gas source nozzle, which is located between the lamp plate and the U-shaped fixing frame and is movable to the position directly below the pinhole of the membrane electrode.

[0018] In the application, the membrane electrode includes a fuel cell membrane electrode and an electrolytic water membrane electrode. Preferably, when the membrane electrode is the electrolytic water membrane electrode, the water source dropper head drops one water drop on the pinhole of the electrolytic water membrane electrode.

[0019] The PEM electrolytic water membrane electrode has a high mechanical strength with a proton exchange membrane thickness of 50-200 um. If the whole membrane is soaked with water, it will be distorted after swelling and it is difficult to restore the flat state, which affects the subsequent assembly of the electrolytic cell. In the application, only one water drop is dropped on the pinhole, and the water drop just covers the surface of the pinhole. The electrolytic water membrane electrode only has a slight deformation at the water dropping position on the pinhole surface. After detection, the water is sucked dry, and the electrolytic water membrane electrode can be restored, which does not affect the subsequent assembly of the electrolytic cell.

[0020] Preferably, the connecting device includes a connecting rod and a screw. One end of the connecting rod is fixed on the lamp plate, and the other end of the connecting rod is detachably connected to the U-shaped fixing frame through the screw.

[0021] Preferably, the shape and size of the U-shaped fixing frame can be replaced to adapt to different types of membrane electrodes.

[0022] Preferably, the clamping device includes a plurality of clamps, which are symmetrically distributed on the edges of the U-shaped fixing frame to uniformly clamp the proton membrane.

[0023] Preferably, a rubber layer is attached to the inner side of the clamp.

[0024] Preferably, the moving path of the gas source nozzle is parallel to the plane of the lamp plate to align with the pinhole position of the membrane electrode.

[0025] The application also provides a membrane electrode pinhole detection method, comprising the following steps:

[0026] The membrane electrode is fixed on the H-shaped fixing frame through the clamping device, and is suspended above the lamp plate;

[0027] The active area of the membrane electrode is irradiated by the lamp plate to identify the position of the pinhole;

[0028] The water source dropper head is controlled to drop water droplets on the surface of the pinhole, so that the water droplets completely cover the pinhole;

[0029] The gas source nozzle is moved to be directly below the pinhole of the membrane electrode, and a preset air pressure is applied;

[0030] It is observed whether bubbles are generated on the surface of the water droplets. Specifically, if bubbles exist, it is determined that the pinhole is a through defect, and the membrane electrode is scrapped.

[0031] Preferably, the applied air pressure ranges from 0.1 MPa to 0.5 MPa, and the duration is 5 seconds to 20 seconds.

[0032] Preferably, the coverage area of the water droplets is greater than the diameter of the pinhole, and generally, the coverage area of the water droplets is 3 times to 5 times the diameter of the pinhole. Preferably, the gas source of the compressed gas source nozzle comprises at least one of air, nitrogen, oxygen and helium.

[0033] The application has the following beneficial effects:

[0034] The application uses the positioning pinhole, water droplet covering and air pressure detection method, does not need to put the membrane electrode into the electrolytic cell, shortens the detection time from several hours to several minutes, and performs low-pressure operation throughout the process. Only gas and water are used in the test process, and the membrane electrode is normally operated to generate gas by electrolyzing water, so that the membrane electrode is not polluted or damaged, that is, nondestructive testing.

[0035] The application uses the water droplet covering and air pressure penetration principle, only the through pinhole can generate bubbles, and the non-through pinhole (no need to be processed) and the through pinhole (need to be scrapped) can be clearly distinguished, so that the problem that the traditional air tightness test cannot locate and qualitatively determine the defects is solved.

[0036] The device of the application adopts a detachable H-shaped fixing frame and a rubber clamping structure, does not need complex assembly, and can be completed by ordinary operators; and the device has low manufacturing cost, is compatible with various membrane electrode models, and significantly reduces the investment and maintenance cost of the detection equipment.

[0037] The application can support the detection requirements of various membrane electrodes (such as circular, rectangular and special-shaped) by replacing the H-shaped fixing frame with different shapes and sizes, and meets the diversified production scenes of PEM electrolytic cells.

[0038] The present application can avoid the potential explosion risk of hydrogen-oxygen mixture in traditional high-pressure test, and quickly identify and reject the membrane electrode with a through pinhole, thereby reducing the safety hazard of electrolytic tank operation from the source.

[0039] The present application solves the pain points of low efficiency, high damage risk and inability to accurately qualitatively defect of traditional technology through structural innovation and detection method optimization, and provides an efficient, safe and low-cost integrated solution for PEM electrolytic tank membrane electrode quality control. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the basis of the drawings shown.

[0041] Figure 1 It is a partial schematic view of the membrane electrode pinhole detection device in an embodiment;

[0042] Figure 2 It is a partial schematic view of the membrane electrode pinhole detection device in an embodiment;

[0043] Figure 3 It is a partial schematic view of the clamping device of the membrane electrode pinhole detection device in an embodiment;

[0044] Figure 4 It is a partial schematic view of the membrane electrode pinhole detection device in an embodiment;

[0045] Figure 5 It is a schematic view of the membrane electrode in an embodiment.

[0046] In the figure, 100 is a lamp plate; 200 is a connecting device; 210 is a connecting rod; 220 is a screw; 300 is a H-shaped fixing frame; 400 is a clamping device; 410 is a clamp; 420 is a rubber layer; 500 is a water source dropper head; 600 is a gas source nozzle; 700 is a membrane electrode; 710 is a proton membrane; 720 is an active area; 730 is a pinhole; and 800 is a water droplet.

[0047] The implementation, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0048] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all the other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0049] It should be noted that all the direction indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are only used to explain the relative position relationship, movement condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the direction indications also change accordingly.

[0050] In addition, the descriptions of "first", "second" and the like in the present application are only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include at least one of the features. In addition, "and / or" throughout the text includes three solutions, for example, A and / or B includes A technical solution, B technical solution, and A and B simultaneously meet the technical solution; in addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of a person of ordinary skill in the art, when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection claimed by the present application.

[0051] As shown in Figure 1 A membrane electrode pinhole detection device includes a lamp plate 100, a connecting device 200, a hui-shaped fixing frame 300, a clamping device 400, a water source dropper head 500, and a gas source nozzle 600.

[0052] One end of the connecting device 200 is connected with the lamp plate 100;

[0053] The hui-shaped fixing frame 300 is connected with one end of the connecting device 200, and the hui-shaped fixing frame 300 is detachably installed above the lamp plate 100 through the connecting device 200;

[0054] The clamping device 400 is arranged on the hui-shaped fixing frame 300, and the clamping device 400 is used for clamping the edge of the proton membrane 710 of the membrane electrode 700, so that the membrane electrode 700 is suspended above the lamp plate 100; the lamp plate 100 is used for observing whether the active area 720 of the membrane electrode 700 has a pinhole;

[0055] The water source drip pipe head 500 is arranged above the H-shaped fixing frame 300, and the water source drip pipe head 500 can be moved to be directly above the needle hole 730 of the membrane electrode 700.

[0056] The gas source nozzle 600 is located between the lamp plate 100 and the H-shaped fixing frame, and the gas source nozzle can be moved to be directly below the needle hole 730 of the membrane electrode 700.

[0057] In some embodiments, as shown in the figure, the connecting device 200 includes a connecting rod 210 and a screw 220, one end of the connecting rod 210 is fixed on the lamp plate 100, and the other end of the connecting rod 210 is detachably linked with the H-shaped fixing frame 300 through the screw 220. Figure 2

[0058] In some embodiments, the shape and size of the H-shaped fixing frame 300 can be replaced to adapt to different models of membrane electrodes 700. When the membrane electrode 700 is changed, only the corresponding H-shaped fixing frame 300 needs to be replaced, so as to be compatible with membrane electrodes 700 of various sizes and shapes. More specifically, the detection of the membrane electrode of the application can be the detection of the membrane electrode when it is factory-finished, or the detection of the membrane electrode that has been working.

[0059] In some embodiments, the clamping device 400 includes a plurality of clamps 410, and the plurality of clamps 410 are symmetrically distributed on the edges of the H-shaped fixing frame 300 to uniformly clamp the proton membrane 710.

[0060] In some embodiments, as shown in the figure, the inside of the clamp 410 is attached with a rubber layer to prevent damage to the proton membrane 710 when clamping the membrane electrode 700. Figure 3

[0061] In some embodiments, the moving path of the gas source nozzle 600 is parallel to the plane of the lamp plate 100 to align with the position of the needle hole 730 of the membrane electrode 700.

[0062] The application also provides a method for detecting the needle hole 730 of the membrane electrode 700, which includes the following steps:

[0063] S100. The membrane electrode 700 is fixed on the H-shaped fixing frame 300 by the clamping device 400, and is suspended above the lamp plate 100; as shown in the figure, the membrane electrode 700 is composed of a proton membrane 710 and an active area 720, wherein the active area 720 is the area of the proton membrane 710 covered by the catalyst layer in the membrane electrode 700 (MEA), which is the core functional area where the electrochemical reaction (water splitting into hydrogen and oxygen) occurs. Figure 4

[0064] ​​​S200. Irradiate the active area 720 of the membrane electrode 700 by the light plate 100, and identify the position of the pinhole 730;

[0065] S300. Control the water source dropper head 500 to drop water droplet 800 on the surface of the pinhole 730, so that the water droplet 800 completely covers the pinhole 730; specifically, the water source dropper head 500 can use an automated system, such as a CCD vision to locate the pinhole 730, feed back the position signal to the moving module of the water source dropper head 500, so that the water source dropper head 500 moves to the position of the pinhole 730, and the water source dropper head 500 is controlled by an electromagnetic valve.

[0066] S400. Move the gas source nozzle 600 to be directly below the pinhole 730 of the membrane electrode 700, and apply a preset gas pressure; specifically, the gas source nozzle 600 can use an automated system, such as a CCD vision to locate the pinhole 730, feed back the position signal to the moving module of the gas source nozzle 600, so that the gas source nozzle 600 moves to the position of the pinhole 730, and the gas source nozzle 600 is controlled by an electromagnetic valve.

[0067] S500. Observe whether bubbles are generated on the surface of the water droplet 800. Specifically, if bubbles exist, it is determined that the pinhole 730 is a through defect, and the membrane electrode 700 is scrapped. If no bubbles are generated, it means that the membrane electrode 700 is qualified, and can be further bonded with a proton exchange membrane.

[0068] In some embodiments, the applied gas pressure ranges from 0.1 MPa to 0.5 MPa, and the duration is 5 seconds to 20 seconds.

[0069] In some embodiments, the coverage area of the water droplet 800 is greater than 3 times to 5 times the diameter of the pinhole 730.

[0070] In some embodiments, the gas source of the compressed gas source nozzle 600 includes at least one of air, nitrogen, oxygen, and helium, and generally uses compressed gas.

[0071] The detection specific conditions of each embodiment are shown in Table 1.

[0072] Table 1: Detection conditions of each embodiment

[0073]

[0074] The electrolytic water membrane electrodes of Examples 1 to 7 were assembled into single cells, and performance tests were performed, and the results are shown in Table 2.

[0075] Table 2: Performance of each embodiment tested

[0076]

[0077] From Table 2, it can be seen that the perforation of the membrane electrode will cause the reactants to pass directly through, reducing the effective reaction area, and the voltage will generally decrease significantly, to 50% or less of the normal range (≥1.8 V). It can also cause internal short circuits, and the voltage can drop sharply to near 0 V.

[0078] The detection results of Example 1 and Example 4 are bubbling, indicating that the pinhole is caused by perforation, and the voltage is low when the electrical performance test is performed, which again proves that the pinhole is caused by perforation. It also proves the reliability of the electrolytic water membrane electrode detection device and the detection method provided by the application.

[0079] Comparative Example 1

[0080] Using a common metal clip (without a rubber layer) to hold the membrane electrode, it was found that the edge damage rate of the proton membrane increased (from 0.5% to 15%) after detection, proving the necessity of the rubber layer.

[0081] Comparative Example 2

[0082] The prior art puts the membrane electrode into a clamp with a gas flow field, and the test gas pressure causes the membrane electrode to move from the high pressure side to the low pressure side, and it was found that the active area of the membrane electrode on the low pressure side was damaged by the flow field (the damage rate increased from 0% to 20%), while the suspended membrane electrode effectively avoids this risk.

[0083] Comparative Example 3

[0084] The prior art detects the entire surface of the membrane electrode and cannot indicate the location of the pinhole point, while the application solves this problem by means of lamp panel illumination and water dripping and air blowing, and through analysis of the pinhole, it is determined whether it is caused by material defects or production out of control, guiding production improvement, and the production yield is increased from 90% to 98%.

[0085] Test Example 1

[0086] Test the effect of different gas pressure ranges (0.1-0.5 MPa) on bubble detection:

[0087] When detected at 0.1 MPa, the bubble formation speed is slow and the bubble amount is small.

[0088] When detected at 0.2 MPa, the bubble formation speed is slow and the bubble amount is small.

[0089] When detected at 0.3 MPa, the bubble formation speed is fast and the bubble amount is large, and the bubble formation is the most stable.

[0090] When detected at 0.4 MPa, the bubble formation speed is fast and the bubble amount is large, but the bubble formation is unstable and the bubble splashes to the surrounding.

[0091] When the pressure is 0.5 MPa, the bubble formation is very fast, the bubble quantity is very large, the bubble formation is very unstable, and the bubble water splashes in all directions. The water droplets on the pinhole splash in 3 seconds.

[0092] The above are only preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structural transformation made under the concept of the present application, using the content of the present application specification and drawings, or directly / indirectly applied in other related technical fields is included in the patent protection scope of the present application.

Claims

1. A membrane electrode pinhole detection apparatus, characterized by, The application relates to a lamp plate, a connecting device, a U-shaped fixing frame, a clamping device, a water source dropper head and a gas source nozzle. The application relates to a lamp plate, a connecting device, a U-shaped fixing frame, a clamping device, a water source dropper head and a gas source nozzle. The lamp plate, the connecting device, the U-shaped fixing frame, the clamping device, the water source dropper head and the gas source nozzle are used for testing a membrane electrode. The lamp plate has a light intensity of 100-600 lumens. The connecting device comprises a connecting rod and a screw, one end of the connecting rod is fixed on the lamp plate, and the other end of the connecting rod is detachably connected with the U-shaped fixing frame through the screw. The clamping device comprises a plurality of clamps which are symmetrically arranged on the edges of the U-shaped fixing frame so as to uniformly clamp the membrane electrode. The inner side of the clamp is attached with a rubber layer.

2. The membrane electrode pinhole detection apparatus according to claim 1, characterized by The application further discloses a testing method of the membrane electrode.

3. The membrane electrode pinhole detection apparatus according to claim 1, characterized by The membrane electrode is fixed on the U-shaped fixing frame through the clamping device and is suspended above the lamp plate.

4. The membrane electrode pinhole detection apparatus according to claim 1, characterized by The active area of the membrane electrode is irradiated through the lamp plate to identify the position of the pinhole.

5. The membrane electrode pinhole detection apparatus according to claim 1, characterized by Water drops are added on the surface of the pinhole through the water source dropper head to completely cover the pinhole.

6. The membrane electrode pinhole detection apparatus according to claim 5, characterized by The gas source nozzle is moved to be below the pinhole of the membrane electrode and a preset air pressure is applied.

7. A method for detecting pinholes in a membrane electrode, using the device according to any one of claims 1 to 6, characterized in that Whether bubbles are generated on the surface of the water drops is observed. The applied air pressure ranges from 0.1 MPa to 0.5 MPa and the duration is 5-20 seconds. The covering area of the water drops is larger than the diameter of the pinhole. The gas source of the gas source nozzle comprises at least one of air, nitrogen, oxygen and helium. ​ ​ 8. The method of claim 7, wherein, ​ 9. The method of claim 7, wherein, ​ 10. The method of claim 7, wherein, ​

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