Non-destructive stripping system for a PEMFC proton exchange membrane and method thereof

Abstract

The present application relates to the technical field of proton exchange membrane fuel cell, and particularly relates to a non-destructive stripping system and method for a proton exchange membrane of a PEMFC, which comprises a stripping mechanism and a verification mechanism, the stripping mechanism comprises a stripping container, a hollow clamp and an ultrasonic generating device, the stripping container is used for containing a stripping agent and a catalyst-coated membrane composite to be stripped; the hollow clamp is used for fixing the catalyst-coated membrane composite to be stripped; the ultrasonic generating device is arranged in the stripping container or cooperatively arranged with the stripping container; the verification mechanism comprises a surface topography characterization module and an electrochemical performance test module, the surface topography characterization module is used for detecting the surface topography of the stripped proton exchange membrane, and the electrochemical performance test module is used for detecting the electrochemical performance of the stripped proton exchange membrane. The present application can realize non-destructive removal of a catalyst layer and double protection of a membrane structure and performance, and fundamentally avoids the problems of membrane damage and residue caused by the prior art.

Description

Technical Field

[0001] This invention relates to the field of proton exchange membrane fuel cell technology, and more particularly to a non-destructive stripping system and method for proton exchange membranes in PEMFCs. Background Technology

[0002] As the core component of the membrane electrode assembly (CCM), the proton exchange membrane determines the power generation efficiency of the CCM and the long-term operational life of the proton exchange membrane fuel cell (PEMFC). However, during long-term operation of PEMFC, the performance degradation of the CCM becomes a prominent issue. Among all the components that lead to battery failure, membrane degradation is the most critical factor, but it is difficult to peel off the membrane in the CCM, making accurate analysis challenging.

[0003] Obtaining structurally intact proton exchange membrane (PEMFC) samples without secondary performance damage is essential for systematically studying membrane degradation mechanisms and quantifying the degree of performance degradation. It also provides core theoretical support for subsequent PEMFC modification and optimization, and for extending PEMFC lifetime. Existing CCM stripping techniques primarily target the catalyst layer, all exhibiting the fatal flaw of inadequate PEMFC protection: the high-concentration organic solution-ultrasound synergistic stripping method, oriented towards precious metal recovery, is prone to chemical degradation and physical damage due to the high concentration of solvents and strong ultrasound; the single organic immersion method leads to excessive swelling and deformation of the membrane, destroying its microstructure; and the simple ultrasonic and mechanical stripping methods easily cause surface scratches and overall damage to the membrane, and incomplete stripping leaves residual catalyst layer impurities, interfering with membrane performance characterization. Furthermore, existing devices lack dedicated fixtures, making them prone to stress concentration and membrane damage due to uneven contact, and lack post-stripping membrane performance testing, failing to guarantee the validity of the membrane samples used in research.

[0004] In summary, existing technologies cannot simultaneously preserve both the structure and performance of the proton exchange membrane while stripping the catalyst layer, resulting in the inability to accurately analyze the true degradation law of the membrane, which severely restricts the research on the degradation mechanism of PEMFC and the performance iteration of proton exchange membranes.

[0005] Therefore, developing a non-destructive peeling system and method for PEMFC proton exchange membranes has become a technical challenge that urgently needs to be overcome in this field. Summary of the Invention

[0006] The purpose of this invention is to provide a non-destructive stripping system and method for PEMFC proton exchange membranes, which solves the problems of existing stripping techniques that easily damage the proton exchange membrane, are incompletely stripped, cannot meet the non-destructive separation requirements for CCM decay mechanism research, and lack an integrated detection and recovery mechanism. This invention achieves complete non-destructive separation of the proton exchange membrane and the CCM catalyst layer, providing qualified samples for PEMFC decay mechanism research.

[0007] To achieve the above objectives, the present invention provides the following solution: The present invention provides a non-destructive peeling system for PEMFC proton exchange membranes, including a peeling mechanism and a verification mechanism, wherein the peeling mechanism is used for non-destructive peeling of the proton exchange membrane, and the verification mechanism is used for verifying the non-destructive nature of the peeling process on the proton exchange membrane; The peeling mechanism includes a peeling container, a perforated clamp, and an ultrasonic generator. The peeling container is used to hold the peeling agent and the catalyst coating film composite to be peeled. The perforated clamp is used to fix the catalyst coating film composite to be peeled. The ultrasonic generator is disposed inside the peeling container or is disposed in conjunction with the peeling container. The verification mechanism includes a surface morphology characterization module and an electrochemical performance testing module. The surface morphology characterization module is used to detect the surface morphology of the stripped proton exchange membrane, and the electrochemical performance testing module is used to detect the electrochemical performance of the stripped proton exchange membrane.

[0008] Preferably, the hollow clamp includes an upper clamp and a lower clamp with a symmetrical double-layer structure. The upper clamp and the lower clamp are connected by an adjustable bolt for adjusting the clamping force. The middle area of ​​the upper clamp and the lower clamp are hollowed out, and the hollowed-out shape matches the active area of ​​the catalyst coating film composite to be peeled off.

[0009] Preferably, the stripping container is equipped with a heating element, a temperature sensor, and a magnetic stirring device to ensure stable temperature and uniform distribution of the organic solution.

[0010] Preferably, the ultrasonic generator has an ultrasonic frequency of 40kHz, an adjustable power of 60-150W, and an intermittent working mode.

[0011] Preferably, the surface morphology characterization module includes at least one of an optical microscope, a scanning electron microscope, an atomic force microscope, and a transmission electron microscope; the electrochemical performance testing module includes at least one of a hydrogen permeation testing unit, an electrochemical impedance spectroscopy testing unit, a current-voltage characteristic testing unit, and a proton conductivity testing unit.

[0012] This invention also discloses a non-destructive peeling method for PEMFC proton exchange membranes based on a non-destructive peeling system for PEMFC proton exchange membranes, comprising the following steps: The catalyst-coated film composite to be peeled off is cleaned and fixed in a hollow fixture; Prepare the organic solvent stripping agent, add it to the stripping container, stir thoroughly to ensure the stripping agent is evenly mixed, and heat the stripping container to the set temperature; Place the hollowed-out fixture with the catalyst-coated film composite fixed in it into the stripping container, so that the catalyst-coated film composite is completely immersed in the stripping agent, and soak it at the set temperature for the set time. The ultrasonic generator is activated and the catalyst-coated membrane composite immersed in the stripping agent is ultrasonically treated in an intermittent working mode to peel the catalyst layer off the surface of the proton exchange membrane. Remove the stripped proton exchange membrane from the fixture, rinse it with deionized water to remove residue, and then dry it. The surface morphology and electrochemical performance of the dried proton exchange membrane were tested using a verification institution, and the results were compared with those of the fresh proton exchange membrane to verify the non-destructive nature of the stripping process.

[0013] Preferably, the verification method for testing the stripped proton exchange membrane includes the following steps: Samples were taken from the dried proton exchange membrane to obtain test samples; The surface morphology of the test samples was detected using a surface morphology characterization module. It was determined that the surface of the proton exchange membrane was undamaged, had no residual catalyst layer, and was not significantly different from the surface morphology of a fresh proton exchange membrane. Electrochemical performance testing modules were used to test the electrochemical performance of the samples to determine that the difference between the hydrogen permeation of the proton exchange membrane and that of the fresh proton exchange membrane did not exceed 10%.

[0014] Preferably, the organic solvent stripping agent is an ethanol / deionized aqueous solution with a volume concentration of 40%-80%, and the set temperature of the organic solvent stripping agent is 40-60℃.

[0015] Preferably, the ultrasonic generator has a power of 80-120W and an intermittent working mode in which ultrasonic operation lasts for 40-80 seconds, followed by an intermittent pause of 5-20 seconds, and is repeated until the catalyst layer is completely peeled off.

[0016] Preferably, the drying process of the proton exchange membrane involves placing the rinsed proton exchange membrane in a constant temperature drying oven and drying it at a temperature of 50-70°C for 15-25 hours.

[0017] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a non-destructive peeling system and method for PEMFC proton exchange membranes, including a matching peeling mechanism and a verification mechanism. The various parts work together, ensuring for the first time at the hardware level that the proton exchange membrane achieves both "structural integrity" and "performance non-destruction" after peeling. This provides a reliable sample acquisition platform for attenuation mechanism research, and significantly improves the credibility and value of membrane recycling and reuse. The hollow clamp in the peeling mechanism solves the defects of traditional fixing methods that easily cause stress concentration and physical damage to the membrane. Combined with the mild chemical immersion environment provided by the peeling container and the low-to-medium power intermittent action of the ultrasonic generator, a non-destructive peeling mechanism of chemical swelling and physical vibration is formed. This ensures that the proton exchange membrane substrate does not undergo chemical degradation, excessive swelling, or mechanical damage while efficiently removing the catalyst layer. This fundamentally avoids the problems of membrane damage, incomplete peeling, and catalyst layer residue that exist in existing technologies such as high-concentration organic solvent-ultrasound synergistic method, single organic immersion method, and simple ultrasonic mechanical peeling method. The integrated surface morphology characterization module and electrochemical performance testing module of the verification mechanism give the system the ability to perform in-situ quality assessment of "stripping and verification" for the first time. It can quantitatively evaluate key indicators such as the surface integrity, proton conductivity and hydrogen barrier performance of the stripped membrane, ensuring that the output sample meets the stringent requirements for membrane samples in the study of PEMFC attenuation mechanism.

[0018] This invention enables non-destructive removal of the catalyst layer while preserving the membrane structure and performance, fundamentally avoiding membrane damage and residue problems that are easily caused by existing technologies, and providing a reliable sample acquisition and evaluation platform for the study of PEMFC attenuation mechanism. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings: Figure 1 This is an axial view of the hollowed-out fixture of the present invention; Figure 2 This is an axial view of the peeled container of the present invention; Figure 3 This is a top view of the peeled container of the present invention; Figure 4 This is a flowchart of the non-destructive peeling method for the PEMFC proton exchange membrane of the present invention; Figure 5 This is a flowchart for verifying the non-destructive peeling effect of the present invention; Figure 6The surface morphology of the proton exchange membrane stripped according to the present invention is shown under an optical microscope. Figure 7 The morphology of the surface of the fresh proton exchange membrane of the present invention under an optical microscope; In the diagram: 1. Upper clamp; 2. Lower clamp; 3. Temperature sensor; 4. Peeling container; 5. Magnetic stirring device; 6. Heating element. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0022] Reference Figures 1 to 5 As shown, this embodiment provides a non-destructive peeling system for PEMFC proton exchange membranes, including a peeling mechanism and a verification mechanism. The peeling mechanism is used to non-destructively peel off the proton exchange membrane, and the verification mechanism is used to verify the non-destructive nature of the peeling process on the proton exchange membrane. The peeling mechanism includes a peeling container 4, a perforated clamp, and an ultrasonic generator. The peeling container 4 is used to contain the peeling agent and the catalyst coating film composite to be peeled. The perforated clamp is used to fix the catalyst coating film composite to be peeled. The ultrasonic generator is disposed inside the peeling container 4 or is disposed in conjunction with the peeling container 4. The verification mechanism includes a surface morphology characterization module and an electrochemical performance testing module. The surface morphology characterization module is used to detect the surface morphology of the stripped proton exchange membrane, and the electrochemical performance testing module is used to detect the electrochemical performance of the stripped proton exchange membrane.

[0023] This invention discloses a non-destructive peeling system and method for PEMFC proton exchange membranes, including a peeling mechanism and a verification mechanism. These components work collaboratively, ensuring, for the first time at the hardware level, the dual preservation of the proton exchange membrane's "structural integrity" and "performance without damage" after peeling. This provides a reliable sample acquisition platform for attenuation mechanism research and significantly enhances the credibility and value of membrane recycling. The hollow clamps in the peeling mechanism overcome the shortcomings of traditional fixing methods, which easily cause stress concentration and physical damage to the membrane. Combined with the mild chemical immersion environment provided by the peeling container 4 and the low-to-medium power intermittent action of the ultrasonic generator, a non-destructive peeling mechanism combining chemical swelling and physical vibration is formed. This ensures efficient removal of the catalyst layer while preventing chemical degradation, excessive swelling, or mechanical damage to the proton exchange membrane substrate. It fundamentally avoids problems such as membrane damage, incomplete peeling, and catalyst layer residue found in existing technologies such as high-concentration organic solvent-ultrasound synergistic methods, single organic immersion methods, and simple ultrasonic mechanical peeling methods. The integrated surface morphology characterization and electrochemical performance testing modules of the verification mechanism, for the first time, endow the system with in-situ quality assessment capabilities of "immediate peeling and verification." This allows for quantitative evaluation of key indicators such as the surface integrity, proton conductivity, and hydrogen barrier performance of the peeled membrane, ensuring that the output sample meets the stringent requirements for membrane samples in PEMFC degradation mechanism research. This invention achieves non-destructive removal of the catalyst layer while preserving both membrane structure and performance, fundamentally avoiding membrane damage and residue problems easily caused by existing technologies. It provides a reliable sample acquisition and evaluation platform for PEMFC degradation mechanism research.

[0024] The optimized design further incorporates a symmetrical double-layered upper clamp 1 and a lower clamp 2. The upper clamp 1 and lower clamp 2 are connected by adjustable bolts to adjust the clamping force. Both the upper clamp 1 and lower clamp 2 have a hollowed-out design in the middle, with the hollow shape matching the active area of ​​the catalyst-coated membrane composite to be peeled off. The symmetrical double-layered plate structure of the hollow clamp, with its empty middle area perfectly matching the active areas of the membrane where chemical reactions occur, achieves unobstructed and stress-free fixation of the composite to be peeled off. The hollowed-out area ensures that the chemical solution can fully contact the entire active surface of the membrane, preventing incomplete peeling due to clamp obstruction. The upper clamp 1 and lower clamp 2 are connected by adjustable screws, allowing adjustment of the clamping force according to the membrane thickness. This avoids excessive clamping that damages the membrane or insufficient clamping that fails to hold it in place, preventing physical damage to the membrane caused by uneven contact or excessive pressure in traditional fixing methods, and ensuring the structural integrity of the membrane during the peeling process.

[0025] Further optimization of the design involves installing a heating element 6, a temperature sensor 3, and a magnetic stirring device 5 within the peeling container 4 to ensure stable temperature and uniform distribution of the organic solution. The peeling container 4 contains the peeling agent and the composite to be peeled, ensuring stable temperature and uniform distribution of the organic solution, creating a stable and uniform chemical environment for the peeling process. The peeling container 4 includes a heating element, a temperature sensor, and a magnetic rotor for stirring. The heating element 6 and temperature sensor 3 work together to maintain a constant solution temperature. The magnetic stirring device 5 keeps the solution flowing, ensuring a uniform concentration of the chemical substances throughout the container.

[0026] In one embodiment of the present invention, the stripping container 4 is made of corrosion-resistant and high-temperature-resistant polytetrafluoroethylene.

[0027] In one embodiment of the present invention, the stripping container 4 is heated by a water bath to ensure temperature stability.

[0028] Further optimization involves an ultrasonic generator with an ultrasonic frequency of 40kHz, an adjustable power of 60-150W, and an intermittent operating mode. The adjustable low power and intermittent operating mode of the ultrasonic generator constitute a "gentle" physical action mechanism. Compared to the high-power continuous ultrasound used in existing technologies, this design avoids excessive vibration causing chemical degradation or physical damage to the membrane material. While effectively loosening the catalyst layer, it maximizes the protection of the proton exchange membrane's microstructure from damage. The ultrasonic generator operates intermittently, rather than continuously, to control the intensity and duration of the ultrasonic action.

[0029] To further optimize the scheme, the surface morphology characterization module includes at least one of optical microscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy; the electrochemical performance testing module includes at least one of hydrogen permeation testing unit, electrochemical impedance spectroscopy testing unit, current-voltage characteristic testing unit, and proton conductivity testing unit. The surface morphology characterization module includes at least one of optical microscopy, scanning electron microscopy, atomic force microscopy, and transmission electron microscopy to observe the surface of the membrane from the micrometer to the nanometer scale to ensure the smoothness, presence of cracks, or residues, thus ensuring the integrity of the membrane's physical structure. The electrochemical performance testing module includes at least one of hydrogen permeation testing, electrochemical impedance spectroscopy, current-voltage curves, and proton conductivity testing to quantify the membrane's gas-barrier and conductivity capabilities, and to assess whether the membrane's core functions have degraded. These two modules achieve comprehensive non-destructive testing from "appearance" to "function."

[0030] This invention also discloses a non-destructive peeling method for PEMFC proton exchange membranes based on a non-destructive peeling system for PEMFC proton exchange membranes, comprising the following steps: The catalyst-coated membrane composite to be peeled is cleaned and fixed in a perforated fixture; the CCM to be peeled is cleaned to remove dust, oil and other impurities; the cleaned CCM is fixed in the perforated fixture, and the bolt tightening force is adjusted to ensure that the composite is firmly fixed and there is no obvious pressure deformation, and to ensure that the CCM surface is fully exposed. Prepare an organic solvent stripping agent and add it to the stripping container 4. Stir thoroughly to ensure the stripping agent is evenly mixed, and heat the stripping container 4 to the set temperature. The stripping container 4 is made of corrosion-resistant and high-temperature-resistant polytetrafluoroethylene and is used to contain the stripping agent and the proton exchange membrane and CCM composite to be stripped. The stripping container 4 is equipped with a heating element 6, a temperature sensor 3, and a magnetic stirring device 5 to ensure both temperature control and uniform distribution of the organic solution. Then, prepare organic solutions of different concentrations and add them to the stripping container 4 and stir for 5-10 minutes to ensure that the two are fully mixed. Place the hollowed-out jig with the catalyst-coated film composite fixed in it into the stripping container 4, so that the catalyst-coated film composite is completely immersed in the stripping agent, and soak it at the set temperature for a set time; slowly place the jig with the CCM fixed in it into the stripping container 4, ensuring that the composite is completely immersed in the stripping agent; The ultrasonic generator is activated to perform ultrasonic treatment on the catalyst-coated membrane composite immersed in the stripping agent in an intermittent working mode, so that the catalyst layer is peeled off from the surface of the proton exchange membrane; the solution temperature and soaking time are set by the control system; the soaked CCM clamp assembly is placed in the ultrasonic instrument for a suitable time to achieve the effect of peeling off the catalyst layer; Remove the stripped proton exchange membrane from the fixture, rinse it with deionized water to remove residue, and then dry it. The surface morphology and electrochemical performance of the dried proton exchange membrane were tested using a verification mechanism, and the results were compared with those of the fresh proton exchange membrane to verify the non-destructive nature of the stripping process. Finally, the surface morphology of the dried membrane was observed using a surface morphology characterization module and compared with that of the fresh membrane to determine whether there were any defects on the membrane surface. The electrochemical performance of the proton exchange membrane measured using an electrochemical performance testing module was compared with that of the fresh proton exchange membrane to determine whether the membrane was damaged.

[0031] To further optimize the scheme, the verification agency's testing method for the stripped proton exchange membrane includes the following steps: Samples were taken from the dried proton exchange membrane to obtain test samples; The surface morphology of the test samples was detected using a surface morphology characterization module. It was determined that the surface of the proton exchange membrane was undamaged, had no residual catalyst layer, and was not significantly different from the surface morphology of a fresh proton exchange membrane. Electrochemical performance testing modules were used to test the electrochemical performance of the samples to determine that the difference between the hydrogen permeation of the proton exchange membrane and that of the fresh proton exchange membrane did not exceed 10%.

[0032] During validation, a small piece of the dried membrane was first taken as a test sample. SEM, AFM, and TEM images were captured using an optical microscope to observe the surface morphology of the dried membrane, ensuring it was free of damage and catalyst layer residue. These images were then compared with those of a fresh membrane. Next, hydrogen permeation, EIS / IV electrochemical performance, and proton conductivity tests were performed on the membrane. The test results were compared with those of a fresh CCM to verify whether the membrane had suffered peeling damage and whether it met the requirements for subsequent research and reuse. The surface morphology of the dried membrane observed by SEM, AFM, and TEM images was compared with that of a fresh membrane to determine if any defects were present on the membrane surface. Finally, the measured electrochemical performance of the proton exchange membrane was compared with that of a fresh proton exchange membrane to determine if the membrane was damaged.

[0033] In one embodiment of the present invention, the electrochemical performance testing module requires that the measured value differs from the value of the fresh membrane by no more than 10%, which serves as a quantitative standard for determining "non-destructive" performance. This ensures that the membrane's gas barrier function has not significantly degraded, providing an objective and reliable basis for evaluating the quality of the membrane sample after peeling.

[0034] In one embodiment of the present invention, the membrane performance is tested using a differential pressure testing system. High-purity hydrogen gas at 0.1-0.5 MPa is introduced at the anode, and high-purity nitrogen gas is introduced at the cathode. The hydrogen barrier performance of the membrane is tested, and the structural integrity of the membrane is determined.

[0035] Further optimization of the solution involved using an organic solvent stripper consisting of a 40%-80% (v / v) ethanol / deionized water solution at a set temperature of 40-60°C. The organic solution, a mixture of ethanol and deionized water in a specific ratio, balances stripping efficiency with membrane protection. The ethanol volume percentage, between 40% and 80%, effectively penetrates and swells the catalyst layer while avoiding excessive corrosion of the membrane material by high-concentration organic solvents. Before use, the solution needs to be heated to a set temperature between 40 and 60°C to provide a suitable chemical reaction environment. Gentle heating accelerates the stripping reaction while preventing membrane thermal deformation or chemical degradation that could be caused by high temperatures.

[0036] Further optimization of the design resulted in an ultrasonic generator with a power of 80-120W. The intermittent operating mode involved 40-80 seconds of ultrasonic operation followed by a 5-20 second pause, cycling until the catalyst layer was completely peeled off. These operating parameters enabled a gentle yet effective physical peeling process. The output power of the ultrasonic generator was controlled between 80 and 120 watts, falling within the low-to-medium power range, thus avoiding the destructive impact of high-power ultrasound on the membrane structure. The cyclical operation, with 40-80 seconds of operation followed by a 5-20 second pause instead of continuous operation, prevented the accumulation of heat and vibration, ensuring complete catalyst layer removal while maximizing membrane protection.

[0037] Further optimization of the process involves drying the proton exchange membrane by placing the rinsed membrane in a constant-temperature drying oven at 50-70°C for 15-25 hours. When drying the stripped proton exchange membrane, the rinsed membrane is placed in a temperature-controlled electric thermostatic drying oven. The oven temperature is set between 50 and 70 degrees Celsius to avoid membrane shrinkage, warping, or cracking that may occur with rapid high-temperature drying. The membrane needs to remain inside for 15 to 25 hours until completely dry, removing residual moisture and solvents to prevent interference with electrochemical measurements during subsequent testing. This ensures that the membrane does not deform or degrade during dehydration.

[0038] In one embodiment of the present invention, the temperature of the organic solution is set to 50°C and the soaking time is 60 minutes.

[0039] In one embodiment of the present invention, the ultrasound is performed in an intermittent mode, with 1 minute of ultrasound followed by a 10-second interval, until the catalyst layer is completely peeled off.

[0040] In one embodiment of the present invention, the drying oven temperature of the drying membrane is set to 60°C and left for 20 hours to obtain a proton exchange membrane.

[0041] Specific examples: Reference Figure 1-5 The present invention discloses a non-destructive stripping system for PEMFC proton exchange membranes, comprising a stripping device and a detection system. The systems work together to complete the non-destructive stripping, detection and recovery of the proton exchange membrane and the CCM catalyst layer. The non-destructive stripping process based on the system includes five core steps: pretreatment, stripping agent preparation, stripping operation, post-treatment and non-destructive verification.

[0042] Combination Figures 6-7 and Table 1, Pretreatment: Prepare a 5cm×5cm CCM sample. Wipe the CCM surface with anhydrous ethanol to remove dust, oil and other impurities. After air drying, place it between the upper clamp 1 and the lower clamp 2 of the hollow fixture. Adjust the tightening force of the adjustable bolts to ensure that the CCM composite is firmly fixed and that there is no obvious pressure deformation on the surface. The hollow area of ​​the fixture should completely fit the active area of ​​the CCM to ensure that the subsequent release agent can make full contact.

[0043] Release agent preparation: Prepare a 60% volume concentration ethanol / deionized water solution. Pour the prepared release agent into the PTFE release container 4, turn on the magnetic stirrer 5, and stir for 8 minutes to ensure that the ethanol and deionized water are fully mixed.

[0044] Peeling operation: Slowly place the hollowed-out clamp with the CCM composite fixed into the peeling container 4, ensuring that the CCM is completely immersed in the peeling agent; set the peeling parameters through the control system: peeling temperature 50℃, soaking time 60min, ultrasonic generator power adjusted to 100W, and adopt an intermittent working mode of 60s working and 10s pausing; during the peeling process, the temperature sensor 3 monitors the temperature of the peeling agent in real time, and the heating element 6 automatically adjusts according to the monitoring results to ensure that the temperature is stable at 50℃±2℃, and the magnetic stirring device 5 continuously stirs at low speed to ensure uniform concentration of the peeling agent.

[0045] Post-processing: After the stripping operation is completed, close all modules, remove the hollow clamp from the stripping container 4, and carefully remove the proton exchange membrane; rinse the membrane repeatedly with deionized water 4 times to wash away the residual catalyst particles and stripping agent on the surface; put the rinsed membrane into a constant temperature drying oven, set the temperature to 60℃, and dry for 20 hours to obtain the dried proton exchange membrane.

[0046] Non-destructive verification: ① Refer to Figure 4 , Figure 5 After drying, the proton exchange membrane was sampled and its surface morphology was observed under an optical microscope. The sample was compared with the surface of a fresh proton exchange membrane. The observation results showed that the sample surface was undamaged and had no catalytic layer residue. The morphology was not significantly different from that of the fresh membrane, and the membrane performance testing stage was initiated.

[0047] ② Referring to Table 1, the sampled membrane was fixed on the fixture of the differential pressure testing system. High-purity hydrogen gas at 0.1 MPa was introduced at the anode, and high-purity nitrogen gas was introduced at the cathode. The hydrogen permeation of the membrane was measured by an electrochemical method. The measured hydrogen permeation was compared with that of fresh CCM. The results showed that the two values ​​were basically consistent, indicating that this method achieved non-destructive stripping of the CCM catalyst layer. The structure and performance of the proton exchange membrane were not damaged, and it can be used for subsequent attenuation mechanism research.

[0048] Table 1. Comparison of hydrogen permeation measured by the stripped proton exchange membrane with that measured by the intact CCM. In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0049] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A non-destructive peeling system for PEMFC proton exchange membranes, characterized in that: It includes a stripping mechanism and a verification mechanism. The stripping mechanism is used to strip the proton exchange membrane non-destructively, and the verification mechanism is used to verify the non-destructive nature of the stripping process on the proton exchange membrane. The peeling mechanism includes a peeling container (4), a hollow clamp, and an ultrasonic generator. The peeling container (4) contains a peeling agent and a catalyst coating film composite to be peeled. The hollow clamp is used to fix the catalyst coating film composite to be peeled. The ultrasonic generator is disposed inside the peeling container (4) or is disposed in conjunction with the peeling container (4). The verification mechanism includes a surface morphology characterization module and an electrochemical performance testing module. The surface morphology characterization module is used to detect the surface morphology of the stripped proton exchange membrane, and the electrochemical performance testing module is used to detect the electrochemical performance of the stripped proton exchange membrane.

2. The non-destructive peeling system for PEMFC proton exchange membranes according to claim 1, characterized in that: The hollow clamp includes an upper clamp (1) and a lower clamp (2) with a symmetrical double-layer structure. The upper clamp (1) and the lower clamp (2) are connected by an adjustable bolt to adjust the clamping force. The middle area of ​​the upper clamp (1) and the lower clamp (2) are hollowed out, and the hollowed-out shape matches the active area of ​​the catalyst coating film composite to be peeled off.

3. The non-destructive peeling system for PEMFC proton exchange membranes according to claim 1, characterized in that: The stripping container (4) is equipped with a heating element (6), a temperature sensor (3), and a magnetic stirring device (5) to ensure stable temperature and uniform distribution of organic solution.

4. The non-destructive peeling system for PEMFC proton exchange membranes according to claim 1, characterized in that: The ultrasonic generator has an ultrasonic frequency of 40kHz, an adjustable power of 60-150W, and an intermittent working mode.

5. The non-destructive peeling system for PEMFC proton exchange membranes according to claim 4, characterized in that: The surface morphology characterization module includes at least one of optical microscope, scanning electron microscope, atomic force microscope and transmission electron microscope; the electrochemical performance testing module includes at least one of hydrogen permeation testing unit, electrochemical impedance spectroscopy testing unit, current-voltage characteristic testing unit and proton conductivity testing unit.

6. A method for non-destructive peeling of a PEMFC proton exchange membrane, based on the non-destructive peeling system for PEMFC proton exchange membranes according to any one of claims 1-5, characterized in that, Includes the following steps: The catalyst-coated film composite to be peeled off is cleaned and fixed in a hollow fixture; Prepare an organic solvent stripping agent, add it to the stripping container (4), stir thoroughly to make the stripping agent evenly mixed, and heat the stripping container (4) to the set temperature; Place the hollowed-out jig with the catalyst-coated film composite fixed in the stripping container (4) so ​​that the catalyst-coated film composite is completely immersed in the stripping agent and soaked for a set time at a set temperature. The ultrasonic generator is activated and the catalyst-coated membrane composite immersed in the stripping agent is ultrasonically treated in an intermittent working mode to peel the catalyst layer off the surface of the proton exchange membrane. Remove the stripped proton exchange membrane from the fixture, rinse it with deionized water to remove residue, and then dry it. The surface morphology and electrochemical performance of the dried proton exchange membrane were tested using a verification institution, and the results were compared with those of the fresh proton exchange membrane to verify the non-destructive nature of the stripping process.

7. The non-destructive peeling method for PEMFC proton exchange membranes according to claim 6, characterized in that: The verification method for testing the stripped proton exchange membrane includes the following steps: Samples were taken from the dried proton exchange membrane to obtain test samples; The surface morphology of the test samples was detected using a surface morphology characterization module. It was determined that the surface of the proton exchange membrane was undamaged, had no residual catalyst layer, and was not significantly different from the surface morphology of a fresh proton exchange membrane. Electrochemical performance testing modules were used to test the electrochemical performance of the samples to determine that the difference between the hydrogen permeation of the proton exchange membrane and that of the fresh proton exchange membrane did not exceed 10%.

8. The non-destructive peeling method for PEMFC proton exchange membranes according to claim 6, characterized in that: The organic solvent stripping agent is an ethanol / deionized water solution with a volume concentration of 40%-80%, and the set temperature of the organic solvent stripping agent is 40-60℃.

9. The non-destructive peeling method for PEMFC proton exchange membranes according to claim 6, characterized in that: The ultrasonic generator has a power of 80-120W. The intermittent working mode involves ultrasonic operation for 40-80 seconds, followed by an intermittent pause of 5-20 seconds, and repeating this cycle until the catalyst layer is completely peeled off.

10. The non-destructive peeling method for PEMFC proton exchange membranes according to claim 6, characterized in that: The drying process for proton exchange membranes involves placing the rinsed proton exchange membranes in a constant temperature drying oven and drying them at 50-70℃ for 15-25 hours.

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