Method and device for measuring critical puncture peak height of gas diffusion layer relative to ion conduction diaphragm
By using a breakdown voltage testing device to evaluate the matching degree between the gas diffusion layer and the ion conduction membrane of the compressible fuel cell under pressure, the problem of inaccurate evaluation in the prior art is solved, key design basis is provided, implementation costs are reduced, and stack design is facilitated.
Patent Information
- Application Number
- CN202511714760.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-21
- Publication Date
- 2026-01-09
AI Technical Summary
Existing technologies make it difficult to accurately assess the matching degree between the gas diffusion layer and the ion conduction membrane of the compressible fuel cell under pressure, which leads to a shortened lifespan or failure of the fuel cell stack, and the roughness control of the gas diffusion layer is difficult.
A breakdown voltage testing device is used to establish an electric field between the gas diffusion layer and the ion conduction membrane of the compressible fuel cell by applying pressure and voltage. Current changes are monitored to determine breakdown events, the critical puncture peak height is calculated, and the actual assembly state of the fuel cell is simulated.
It enables direct and accurate measurement under pressure, making the evaluation results more valuable. It provides key design basis for matching the gas diffusion layer and the diaphragm, reduces implementation costs, and facilitates fuel cell stack design.
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Figure CN121298518A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of fuel cell technology, and specifically to a method and apparatus for measuring the critical puncture peak height of the gas diffusion layer relative to the ion conduction membrane. Background Technology
[0002] As a very serious failure mode, damage (perforation) to the compressible fuel cell ion-conducting membrane directly shortens the stack's lifespan and can even lead to direct stack failure (due to short circuits preventing loading). The damage (perforation) to the compressible fuel cell ion-conducting membrane is mainly constrained by the roughness and elastic modulus of the gas diffusion layer, the hardness, fracture toughness, and thickness of the compressible fuel cell ion-conducting membrane, and interfacial loading conditions. Among these factors, the roughness of the gas diffusion layer is one of the important indicators for evaluating its reliability and is also one of the key factors causing mechanical damage to the compressible fuel cell ion-conducting membrane.
[0003] During fuel cell stack design, the compatibility between the gas diffusion layer and the compressible fuel cell ion-conducting membrane must be fully evaluated to ensure stack quality. Given the irreplaceable role of the gas diffusion layer in fuel cell hydrothermal management, membrane electrode assembly (MEA) or fuel cell stack manufacturers must prioritize high-quality gas diffusion layers as a core strategic focus. However, current gas diffusion layer suppliers offer inconsistent product quality, particularly in controlling the roughness of the gas diffusion layer, which presents significant challenges.
[0004] This invention is a method for calibrating the critical puncture peak height of the gas diffusion layer relative to the compressible fuel cell ion conduction membrane of a fuel cell component, and for evaluating the roughness of the gas diffusion layer and the degree of matching between the gas diffusion layer and the compressible fuel cell ion conduction membrane. Summary of the Invention
[0005] In view of this, the purpose of the present invention is to provide a method and apparatus for measuring the critical puncture peak height of the gas diffusion layer relative to the ion conduction membrane, in order to overcome at least one related technical problem existing in the background art.
[0006] To achieve the above objectives, the present invention adopts the following technical solution: A method for measuring the critical puncture peak height of a gas diffusion layer includes the following steps: A breakdown voltage testing device is provided, which includes a conductive plate, a compressible fuel cell ion conduction membrane, an insulating plate, a pressure application device, and a DC power supply. Two gas diffusion layers to be tested are respectively disposed on the two sides of the compressible fuel cell ion conduction membrane, and a conductive plate and an insulating plate are sequentially arranged and a predetermined pressure is applied by the pressure application device. A test voltage is applied between the conductive plate and the gas diffusion layer using the DC power supply. Repeat the above steps using at least two different thicknesses of compressible fuel cell ion conduction membranes to determine the minimum thickness at which the compressible fuel cell ion conduction membrane is broken down as the breakdown thickness, and the maximum thickness at which it is not broken down as the non-breakdown thickness. The critical puncture peak height of the gas diffusion layer is calculated based on the breakdown thickness and the non-breakdown thickness.
[0007] To ensure the stability and applicability of the testing device, in some optional embodiments, the breakdown voltage testing device includes: The conductive plate includes plates made of various conductive materials, such as metal conductive plates or graphite conductive plates; The pressure application device includes hydraulic devices, mechanical presses or pneumatic presses, and various other devices that can provide pressure, such as springs; these features ensure the repeatability and reliability of the test results.
[0008] To address the balance between test safety and measurement validity, in some alternative implementations, the test voltage ranges from 5V to 25V.
[0009] To simulate the actual assembly pressure conditions of a fuel cell stack, in some alternative embodiments, the predetermined pressure ranges from 0.5 MPa to 3 MPa.
[0010] To address the subjective nature of breakdown detection, in some optional implementations, breakdown events are detected by monitoring the circuit current. A breakdown event is determined to have occurred when the current value exceeds a preset threshold or undergoes a sudden change, or when the current reaches a set maximum value but the voltage cannot maintain the set value.
[0011] To balance testing accuracy and efficiency, in some optional implementations, when testing with compressible fuel cell ion conduction membranes of different thicknesses, the thickness variation interval is 0.1 micrometers to 3 micrometers, depending on the product (thickness) of the fuel cell ion conduction membrane. The smaller the thickness difference, the more accurate the test.
[0012] To address the lack of theoretical support for the calculation method, in some optional implementations, the critical puncture peak height is calculated using the following formula: A = k × (T1 + T2) / 2; Where A is the critical puncture peak height, T1 is the breakdown thickness, T2 is the non-breakdown thickness, and k is the proportionality coefficient, ranging from 0.4 to 0.6.
[0013] To address the discrepancy between measurements taken in dry conditions and actual humid environments, some alternative implementations include a step of wetting the gas diffusion layer before testing to simulate the water vapor environment under actual working conditions.
[0014] This embodiment also provides a breakdown voltage testing apparatus for implementing any of the methods described above, comprising: A compressible fuel cell ion conduction membrane, wherein a gas diffusion layer for the test is provided on both sides of the compressible fuel cell ion conduction membrane; A conductive plate, the two conductive plates being respectively disposed on both sides of the gas diffusion layer; An insulating plate, the two insulating plates being respectively disposed on both sides of a conductive plate; A DC power supply, whose positive and negative terminals are respectively connected to conductive plates on both sides, is used to apply a test voltage between the conductive plates and the gas diffusion layer; and a pressure application device connected to an insulating plate.
[0015] In some alternative implementations, the positive and negative terminals of the DC power supply are connected to conductive plates on both sides, respectively.
[0016] The method and apparatus disclosed in this application for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane may have the following beneficial effects, including but not limited to: This invention achieves direct and accurate measurement under pressure: by applying pressure to simulate the actual assembly state and using the physical phenomenon of electrical breakdown to directly detect the risk of puncture, it overcomes the problem that existing optical measurement methods cannot work effectively under pressure. The measurement results are more in line with the actual situation and have high accuracy.
[0017] Strong anti-interference capability and wide applicability: Because it adopts an electrical measurement method, this method is not affected by media such as water and gas at the interface. Therefore, it can be measured under conditions that simulate the wet environment of a real fuel cell, which expands the applicable scenarios of the method and makes the evaluation results more valuable.
[0018] The evaluation metric is direct and has clear engineering significance: The "critical puncture peak height" provided by this invention is a parameter with clear physical meaning and engineering value. It directly characterizes the mechanical safety of the gas diffusion layer when matched with a specific compressible fuel cell ion conduction membrane, providing key design basis for stack designers, facilitating the selection of qualified gas diffusion layer products, and optimizing the assembly process of the membrane electrode assembly.
[0019] Comprehensive assessment of the impact of different operating conditions: By systematically changing parameters such as applied pressure, thickness of the compressible fuel cell ion conduction membrane, and ambient humidity, this invention can conveniently study the impact of different operating conditions on the critical puncture peak height, providing a powerful tool for the reliability assessment of fuel cells under different operating conditions.
[0020] The device is simple, inexpensive, and easy to implement: The device involved in this invention has a simple structure, mainly including a common press, DC power supply and conductive components. It does not require expensive optical or thermal imaging equipment, which reduces the implementation cost and technical threshold, and makes it easy to promote and use in production lines or laboratories. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the breakdown voltage testing device of the present invention. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar components or components having the same or similar functions throughout. The described embodiments are some, but not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.
[0023] See Figure 1 A method for measuring the critical puncture peak height of a gas diffusion layer includes the following steps: A breakdown voltage testing device is provided, comprising a conductive plate, a compressible fuel cell ion-conducting membrane, an insulating plate pressure application device, and a DC power supply. Two gas diffusion layers to be tested are respectively disposed on the two sides of the compressible fuel cell ion conduction membrane, and a conductive plate and an insulating plate are sequentially arranged and a predetermined pressure is applied by the pressure application device. A test voltage is applied between the conductive plate and the gas diffusion layer using the DC power supply. Repeat the above steps using at least two different thicknesses of compressible fuel cell ion conduction membranes to determine the minimum thickness at which the compressible fuel cell ion conduction membrane is broken down as the breakdown thickness, and the maximum thickness at which it is not broken down as the non-breakdown thickness. The critical puncture peak height of the gas diffusion layer is calculated based on the breakdown thickness and the non-breakdown thickness.
[0024] To address the issue that existing optical measurement methods cannot accurately measure the roughness of the gas diffusion layer under pressure, the gas diffusion layer is brought into contact with a compressible fuel cell ion conduction membrane and pressure is applied. The critical puncture peak height is directly obtained through breakdown voltage testing, avoiding interference from interfacial media (such as water vapor) and improving the accuracy and practicality of the measurement.
[0025] First, a test setup is assembled, bringing the gas diffusion layer into close contact with the compressible fuel cell ion conduction membrane. A pressure application device applies a predetermined pressure to simulate the actual assembly state. A DC power supply establishes an electric field between the conductive plate and the gas diffusion layer. Tests are conducted by replacing the compressible fuel cell ion conduction membrane with membranes of different thicknesses to detect breakdown events (such as short circuits). Finally, the critical puncture peak height is calculated based on the breakdown and non-breakdown thicknesses. The core of this method lies in directly reflecting the puncture risk of the compressible fuel cell ion conduction membrane to the surface peak height of the gas diffusion layer through the electrical breakdown phenomenon.
[0026] To ensure the stability and applicability of the testing device, in some optional embodiments, the breakdown voltage testing device includes: The conductive plate includes plates made of various conductive materials, such as metal conductive plates or graphite conductive plates; The pressure application device includes hydraulic devices, mechanical presses or pneumatic presses, and various other devices that can provide pressure, such as springs; these features ensure the repeatability and reliability of the test results.
[0027] The DC power supply includes various types of power sources capable of providing DC power; the compressible fuel cell ion conduction membrane includes a proton exchange membrane and an anion exchange membrane, such as a perfluorosulfonic acid proton exchange membrane.
[0028] To address the balance between test safety and measurement validity, in some alternative implementations, the test voltage ranges from 5V to 25V. Limiting the test voltage to this range prevents damage from excessively high voltages or failure to induce breakdown due to excessively low voltages; the proton exchange membrane thickness is set to a range of 5-30 micrometers to cover typical fuel cell applications, ensuring the measurement results have practical reference value.
[0029] The DC power supply provides a stable electric field within this voltage range. The thickness of the proton exchange membrane is varied by replacing the membrane with different specifications. During the test, the thickness is gradually adjusted to find the critical point.
[0030] To simulate the actual assembly pressure conditions of a fuel cell stack, in some optional embodiments, the predetermined pressure ranges from 0.5 MPa to 3 MPa. This makes the measurement environment closer to real operating conditions and improves the practicality of the evaluation results. The pressure application device applies pressure according to the set value to ensure that the interface between the gas diffusion layer and the compressible fuel cell ion conduction membrane is under pressure, simulating the interface conditions after the stack is assembled.
[0031] It should be noted that the pressure range can be adjusted according to the specific fuel cell stack design, for example, extended to 0.1MPa-5MPa, but the above range already covers most application scenarios.
[0032] To address the subjectivity of breakdown detection, in some optional implementations, breakdown events are detected by monitoring the circuit current. A breakdown event is determined to have occurred when the current value exceeds a preset threshold, undergoes a sudden change, or when the current reaches a set maximum value but the voltage fails to maintain that value. Setting the detection method to current monitoring accurately identifies breakdown through objective electrical signal changes (such as sudden current changes), avoiding visual or human errors and improving test reliability.
[0033] When a DC power supply applies voltage, the current sensor monitors the loop current in real time; once the current exceeds a threshold (e.g., short-circuit current), the system automatically records the breakdown event.
[0034] To balance testing accuracy and efficiency, in some optional implementations, when testing with compressible fuel cell ion-conducting membranes of varying thicknesses, the thickness variation interval is 0.1 micrometers to 3 micrometers. This avoids excessively large intervals that lead to rough measurements or excessively small intervals that increase testing time, ensuring that high-precision results are obtained within a reasonable time.
[0035] During the test, the proton exchange membrane thickness was increased or decreased in increments of 1-3 micrometers until adjacent thicknesses of breakdown and non-breakdown were found.
[0036] Of course, the interval can be adjusted to more than 3 micrometers, but the larger the interval, the worse the accuracy. To reduce the number of tests, you can choose 1-3 micrometers as the step size to achieve a rough initial selection.
[0037] To address the lack of theoretical support for the calculation method, in some optional implementations, the critical puncture peak height is calculated using the following formula: A = k × (T1 + T2) / 2; Where A is the critical penetration peak height, T1 is the breakdown thickness, T2 is the non-breakdown thickness, and k is a proportionality coefficient ranging from 0.4 to 0.6. The formula is set to be based on the average of the breakdown and non-breakdown thicknesses, and the proportionality coefficient k is introduced to consider the actual interface stress distribution, making the calculation results more consistent with physical reality and improving the accuracy of the assessment. After obtaining T1 and T2 through testing, A is calculated by substituting them into the formula. The value of k can be calibrated experimentally (usually taken as 0.5).
[0038] To address the discrepancy between measurements taken under dry conditions and actual humid environments, some optional implementations include a step of wetting the gas diffusion layer before testing to simulate the moisture environment under real-world operating conditions. Incorporating wetting into the testing process makes the measurement conditions closer to the operating state of a fuel cell, improving the applicability of the results.
[0039] Before testing, the gas diffusion layer is moistened by spraying, soaking, or humidifying. Then, the breakdown voltage test is performed.
[0040] Specifically, humidification methods may include steam treatment or ambient humidity control, but spraying is simpler.
[0041] This embodiment also provides a breakdown voltage testing apparatus for implementing any of the methods described above, comprising: A compressible fuel cell ion conduction membrane, wherein a gas diffusion layer for the test is provided on both sides of the compressible fuel cell ion conduction membrane; A conductive plate, the two conductive plates being respectively disposed on both sides of the gas diffusion layer; An insulating plate, the two insulating plates being respectively disposed on both sides of a conductive plate; A DC power supply, whose positive and negative terminals are respectively connected to conductive plates on both sides, is used to apply a test voltage between the conductive plates and the gas diffusion layer; and a pressure application device connected to an insulating plate.
[0042] To provide an integrated and operable hardware platform specifically for implementing the above methods, this symmetrically stacked device was designed. This device ensures uniform pressure distribution and stable electric field direction, and effectively isolates the pressure mechanism from the circuit system through an insulating plate, enabling safe and reliable testing under realistic simulated operating conditions.
[0043] The pressure application device acts on the insulating plate, which transmits the pressure to the conductive plate, which in turn transmits the pressure to the gas diffusion layer, ensuring close contact between the gas and the compressible fuel cell ion-conducting membrane. The positive and negative terminals of the DC power supply are connected to the conductive plates on both sides, thereby creating a test electric field across the entire test assembly.
[0044] In some alternative implementations, the positive and negative terminals of the DC power supply are connected to conductive plates on both sides, respectively.
[0045] To establish a uniform, stable electric field perpendicular to the membrane surface, a scheme was adopted in which the positive and negative terminals of the power supply were directly connected to the conductive plates on both sides. This connection method ensures that the electric field lines pass perpendicularly through the compressible fuel cell ion conduction membrane, so that the breakdown event is triggered by the sharpest protrusion (puncture peak) on the surface of the gas diffusion layer, and the measurement results directly reflect the most dangerous puncture risk.
[0046] In this configuration, the electric field flows from the positive electrode conductive plate, through the gas diffusion layer, the compressible fuel cell ion-conducting membrane, the other gas diffusion layer, and finally to the negative electrode conductive plate. Peaks on the surface of any gas diffusion layer are within a strong electric field, making them most susceptible to causing membrane breakdown in front of them.
[0047] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention.
[0048] Example 1: Measurement of the critical puncture peak height of a two-sided structure under standard dry conditions In this embodiment, the compressible fuel cell ion conduction membrane is a proton exchange membrane.
[0049] This embodiment aims to demonstrate the basic operating procedures and effects of the method of the present invention under standard conditions.
[0050] Test preparation: Device assembly: Refer to Figure 1 Assemble the test apparatus from bottom to top as follows: insulating plate -> conductive plate -> gas diffusion layer -> proton exchange membrane (initial thickness 15.0 micrometers) -> gas diffusion layer -> conductive plate -> insulating plate. Place the entire assembly on the pressure table of the hydraulic press.
[0051] Circuit connection: Connect the positive terminal of the DC power supply to the upper conductive plate and the negative terminal to the lower conductive plate.
[0052] Parameter settings: Set the pressure provided by the hydraulic press to 1.5MPa. Set the DC power supply output voltage to 5V. Set the current breakdown threshold to 25A or 50A (the significant characteristics of breakdown are high current and low voltage).
[0053] Test Procedure and Data Recording: The critical breakdown point was determined by using proton exchange membranes of varying thicknesses. The test data is recorded below:
[0054] Result calculation: Breakdown thickness (T1): 7.0 micrometers Non-breakdown thickness (T2): 8.0 micrometers Taking the proportionality coefficient k=0.5 (an empirical value based on a large number of experiments), the critical puncture peak height A is calculated according to the formula in claim 7: A = k × (T1 + T2) / 2 = 0.5 × (7.0 + 8.0) / 2 = 0.5 × 7.5 = 3.75 micrometers.
[0055] Conclusion: Under the conditions of this embodiment, the critical puncture peak height of this batch of gas diffusion layer is 3.75 micrometers. This result clearly indicates that, when used with this diffusion layer, the equivalent safe thickness of the proton exchange membrane at a pressure of 1.5 MPa needs to be greater than 2 × 3.75 = 7.5 micrometers.
[0056] Example 2: Measurement Comparison under Humid Environment This embodiment demonstrates the application of the present invention in a simulated real wet environment of a fuel cell and compares it with a dry environment.
[0057] Test preparation: The device assembly and circuit connection are the same as in Example 1.
[0058] Wetting treatment: Before assembly, use a precision sprayer to evenly spray deionized water onto the test surfaces (the surfaces in contact with the proton exchange membrane) of the two gas diffusion layers until their weight increases by about 15%.
[0059] Parameter settings: Pressure and voltage settings are the same as in Example 1 (1.5MPa, 5V).
[0060] Test steps and data recording:
[0061] Result calculation: Breakdown thickness (T1): 10.0 micrometers Non-breakdown thickness (T2): 11.0 micrometers Calculate the critical puncture peak height A under wet conditions: A = 0.5 × (10.0 + 11.0) / 2 = 5.25 micrometers Conclusions and Comparative Analysis: Under humid conditions, the measured critical puncture peak height was 5.25 μm, significantly higher than the 3.75 μm under dry conditions. This demonstrates that the presence of water molecules alters the cross-sectional properties of the gas diffusion layer and the proton exchange membrane, making the proton exchange membrane more easily punctured. This embodiment highlights the unique advantage of the method of the present invention in effectively assessing wet operating conditions, which is impossible with traditional optical methods.
[0062] Comparative Example: Compared with Traditional Optical Measurement Methods The gas diffusion layer sample from the same batch as in Example 1 was used to measure the surface morphology in its free state (without pressure) using a high-precision white light interferometer.
[0063] Measurement results: The arithmetic mean roughness Ra was measured to be 6.8 micrometers, and the ten-point mean roughness Rz was measured to be 18.5 micrometers.
[0064] Analysis and Discussion: Parameters such as Ra and Rz obtained by optical measurement methods describe the overall profile of the sample in a free state, but cannot distinguish which profile peaks are the "danger peaks" that truly pose a puncture threat under specific pressure.
[0065] The critical puncture peak height (3.75 micrometers) directly provided by the method of this invention is a functional parameter. It clearly answers the core engineering question of "how thick a proton exchange membrane is needed for safe protection under 1.5 MPa pressure".
[0066] This invention simulates a bilaterally symmetrical stress structure, which more realistically reflects the actual stress state of the membrane in the fuel cell stack, something that optical measurement or single-sided test models cannot achieve.
[0067] Therefore, this invention achieves a leap from morphological description to functional risk assessment, providing direct and crucial quantitative basis for the selection and assembly process of membrane electrodes.
[0068] Example 3: Impact Assessment under Different Pressures This embodiment demonstrates how the method of the present invention evaluates the effect of assembly pressure on the critical puncture peak height.
[0069] Test preparation: Same as in Example 1, but without wetting.
[0070] Tests and Results: The steps of Example 1 were repeated at pressures of 1.0 MPa and 2.5 MPa, respectively.
[0071] At 1.0 MPa, T1 = 5.0 μm and T2 = 6.0 μm were measured, and A = 2.75 μm was calculated.
[0072] At 2.5 MPa, T1 = 9.0 μm and T2 = 10.0 μm were measured, and A = 4.75 μm was calculated.
[0073] Conclusion: As the assembly pressure increased from 1.0 MPa to 2.5 MPa, the critical puncture peak height increased from 2.75 μm to 4.75 μm. This indicates that at higher pressures, the protrusions on the gas diffusion layer surface embed more deeply into the proton exchange membrane, significantly increasing the risk of puncture. This embodiment demonstrates that the method of the present invention can accurately quantify the impact of pressure, a key process parameter, on the mechanical reliability of the membrane electrode, providing scientific data support for optimizing the fuel cell stack assembly process.
[0074] The various embodiments of this application have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.
Claims
1. A method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane, characterized in that, Includes the following steps: A breakdown voltage testing device is provided, which includes a conductive plate, a compressible fuel cell ion conduction membrane, an insulating plate, a pressure application device, and a DC power supply. Two gas diffusion layers to be tested are respectively disposed on the two sides of the compressible fuel cell ion conduction membrane, and a conductive plate and an insulating plate are sequentially arranged and a predetermined pressure is applied by the pressure application device. A test voltage is applied between the conductive plate and the gas diffusion layer using the DC power supply. Repeat the above steps using at least two different thicknesses of compressible fuel cell ion conduction membranes to determine the minimum thickness at which the compressible fuel cell ion conduction membrane is broken down as the breakdown thickness, and the maximum thickness at which it is not broken down as the non-breakdown thickness. The critical puncture peak height of the gas diffusion layer is calculated based on the breakdown thickness and the non-breakdown thickness.
2. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, In the breakdown voltage testing device: The pressure application device includes a hydraulic device, a mechanical press, or a pneumatic press; The compressible fuel cell ion-conducting membrane includes a proton exchange membrane and an anion exchange membrane.
3. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, The test voltage range is 5V to 25V.
4. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, The predetermined pressure ranges from 0.5 MPa to 3 MPa.
5. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, Breakdown events are detected by monitoring the circuit current. When the current value exceeds the preset threshold or changes abruptly, or when the current reaches the set maximum value but the voltage cannot maintain the set value, a breakdown event is determined to have occurred.
6. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, When testing was conducted using compressible fuel cell ion-conducting membranes of varying thicknesses, the thickness variation intervals ranged from 0.11 micrometers to 3 micrometers.
7. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, The critical puncture peak height is calculated using the following formula: A=k×(T1+T2) / 2; Where A is the critical puncture peak height, T1 is the breakdown thickness, T2 is the non-breakdown thickness, and k is the proportionality coefficient, ranging from 0.4 to 0.
6.
8. The method for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 1, characterized in that, It also includes a step of wetting the gas diffusion layer before testing to simulate the water vapor environment under actual working conditions.
9. An apparatus for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane, used to implement the method described in any one of claims 1-8, characterized in that, include: A compressible fuel cell ion conduction membrane, wherein a gas diffusion layer for the test is provided on both sides of the compressible fuel cell ion conduction membrane; A conductive plate, the two conductive plates being respectively disposed on both sides of the gas diffusion layer; An insulating plate, the two insulating plates being respectively disposed on both sides of a conductive plate; A DC power supply, whose positive and negative terminals are respectively connected to conductive plates on both sides, is used to apply a test voltage between the conductive plates and the gas diffusion layer; and a pressure application device connected to an insulating plate.
10. The apparatus for measuring the critical puncture peak height of a gas diffusion layer relative to an ion-conducting membrane as described in claim 9, characterized in that, The positive and negative terminals of the DC power supply are connected to the conductive plates on both sides, respectively.