A method and system for testing the resistance of a proton exchange membrane fuel cell anode to co-poisoning

Abstract

This invention discloses a method and system for testing the CO poisoning resistance of a proton exchange membrane fuel cell anode. The method includes: activating the fuel cell and recording its initial voltage and initial high-frequency impedance; momentarily introducing an excessive concentration of CO-containing gas through a three-way connector at the anode inlet and then closing it, causing anode poisoning and resulting in voltage and impedance deviations from their initial values; continuing constant current operation to restore the voltage to its initial value; then introducing inert gas for purging and followed by oxygen-containing gas to restore the high-frequency impedance to its initial value; and evaluating the CO poisoning resistance based on the recovery of voltage and impedance. The system includes a fuel cell testing system, a data acquisition unit, a CO gas source, an inert gas source, an oxygen-containing gas source, a control unit, and an evaluation unit. This invention requires no modification to existing testing systems and has advantages such as simplicity, low cost, high repeatability, high accuracy, high sensitivity, short testing time, and high safety.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell testing technology, specifically relating to a test method and system for CO poisoning resistance of a proton exchange membrane fuel cell anodes, so as to achieve efficient, accurate and low-cost evaluation of the CO poisoning resistance performance of anode catalysts. Background Technology

[0002] Proton exchange membrane fuel cells (PEMFCs) use hydrogen as fuel and offer advantages such as high energy conversion efficiency, fast start-up, and zero emissions, making them an important direction for future clean energy technologies. However, hydrogen used in practice typically contains trace amounts of CO impurities. CO strongly adsorbs onto the surface of the anode catalyst, occupying catalytic active sites and leading to a significant decline in battery performance. Therefore, accurately evaluating the CO poisoning resistance of the anode catalyst is crucial for catalyst screening and battery development.

[0003] Currently, the testing methods for evaluating the CO poisoning resistance of PEMFC anodes are mainly divided into four categories: (1) Electrochemical performance testing, mainly conducted in single cells, with a certain concentration of [unspecified substance] used at the anode. The mixed gas is used to test polarization curves. Its advantage is that it most closely approximates real-world application conditions, directly evaluating the overall CO resistance of the MEA; however, its disadvantages include the inability to distinguish mass transfer and catalyst kinetic mechanisms, the influence of temperature, gas flow rate, and water management on test results, and the need for a complete fuel cell testing system, i.e., adding a hydrogen and CO mixing device to the testing equipment or customizing a specific concentration of CO. The cost of testing equipment and modifications for mixed gases is relatively high.

[0004] (2) Electrochemical diagnostic testing, usually using electrochemical impedance spectroscopy, is used to diagnose the effect of CO on anode kinetics. Its advantages are that it can explain the mechanism of the electrode and study CO adsorption kinetics; however, its disadvantages are that there are uncertainties in the equivalent circuit model, the test time is long, and a complete fuel cell test system is still required.

[0005] (3) Half-cell catalyst testing is usually conducted in a three-electrode system using methods such as cyclic voltammetry, chronoamperometry, or electrochemical impedance spectroscopy. Its advantage is that it can directly measure the CO adsorption amount and study the catalyst's resistance to CO poisoning mechanism; however, its disadvantage is that it differs from the actual working conditions of PEMFC and cannot directly reflect the performance of MEA.

[0006] (4) In-situ testing methods mainly use mass spectrometry, isotope analysis, etc., to simultaneously analyze anode tail gas, CO conversion rate and CO surface coverage during battery operation. Its advantage is strong in-situ mechanism research capability, but its disadvantages are complex experimental system, high cost and complicated data processing.

[0007] In summary, among existing testing methods, in-situ testing is costly and complex, making it difficult to scale up; half-cell testing is mainly used to characterize catalysts and cannot accurately reflect the performance of the MEA; while electrochemical performance testing in single cells can accurately reflect the performance of the MEA, it requires modification of existing fuel cell testing systems to accommodate the necessary modifications. Hybrid testing devices incur significant costs in terms of both equipment and modification. For example, conventional single-cell testing typically requires a continuous flow of 50 ppm of [unspecified substance]. It requires a mixed gas and a dedicated gas mixing device, which results in high modification costs.

[0008] Therefore, there is an urgent need for a PEMFC anode CO poisoning resistance testing method that can accurately reflect MEA performance, does not require modification of existing fuel cell testing systems, and is simple and easy to operate. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a method and system for testing the CO poisoning resistance of proton exchange membrane fuel cell anodes, overcoming the technical shortcomings of existing technologies, such as high modification costs, complex operation, and difficulty in balancing realism and ease of use.

[0010] To address the aforementioned technical issues, this invention constructs a three-stage testing process of "pulse poisoning + in-situ recovery + impedance repair," utilizing instantaneous pulse injection of high-concentration CO to replace traditional continuous low-concentration CO ventilation, thereby achieving CO poisoning resistance performance evaluation without modifying existing testing systems.

[0011] The system adopts a modular architecture, consisting of a fuel cell testing system, a data acquisition unit, a CO gas source, an inert gas source, an oxygen-containing gas source, a control unit, and an evaluation unit. The modules work together to form a complete testing closed loop.

[0012] Specifically, this invention activates the fuel cell under test to a stable state under set operating conditions, recording the initial operating voltage and initial high-frequency impedance. While maintaining a constant current density, an excessive concentration of CO-containing gas is instantaneously introduced into the anode inlet through a three-way connector connected to the anode inlet, and then immediately shut off, causing instantaneous poisoning of the anode, resulting in the operating voltage and high-frequency impedance deviating from their initial values. The system continues to operate at a constant current density for a second preset time to restore the operating voltage to its initial value. After the operating voltage recovers, inert gas is introduced into the anode for purging, followed by the introduction of oxygen-containing gas to restore the high-frequency impedance to its initial value. Finally, the anode's resistance to CO poisoning is evaluated based on the recovery of the operating voltage and high-frequency impedance.

[0013] Therefore, this invention enables PEMFC anode CO poisoning resistance testing without modifying existing fuel cell testing systems, and features simple operation, low testing cost, high repeatability, high accuracy, high sensitivity, short testing time, and high safety.

[0014] According to one aspect of the present invention, a method for testing the CO poisoning resistance of a proton exchange membrane fuel cell anode is provided, comprising the following steps: The fuel cell was activated to a stable state under set operating conditions and operated at a constant current density for a first preset time. The operating voltage of the battery was recorded as the initial voltage, and the high-frequency impedance of the battery was recorded as the initial impedance. While maintaining the constant current density, an excessive concentration of CO-containing gas is instantaneously introduced into the anode inlet through a three-way connector connected to the anode inlet and then immediately shut off, causing the anode to be momentarily poisoned. This results in the battery's operating voltage deviating from the initial voltage, and the battery's high-frequency impedance deviating from the initial impedance. Continue operating at the constant current density for a second preset time to restore the battery's operating voltage to the initial voltage; After the battery's operating voltage recovers to the initial voltage, inert gas is introduced into the anode for purging, and then oxygen-containing gas is introduced into the anode to restore the battery's high-frequency impedance to the initial impedance. The resistance of the anode to CO poisoning is evaluated based on the recovery of the operating voltage and the recovery of the high-frequency impedance.

[0015] In another aspect, the present invention provides a CO poisoning resistance testing system for the anode of a proton exchange membrane fuel cell, comprising: A fuel cell testing system is used to provide the fuel cell under test with set operating conditions and to operate the fuel cell at a constant current density. The data acquisition unit is used to record the operating voltage and high-frequency impedance of the fuel cell; A CO gas source is connected to the fuel cell via a three-way connector at the anode inlet, and is used to instantaneously introduce an excessive concentration of CO-containing gas into the anode inlet. An inert gas source is used to introduce inert gas into the anode for purging; An oxygen source is used to introduce oxygen-containing gas into the anode; The control unit is used to control the on / off timing of the CO gas source, the inert gas source and the oxygen-containing gas source, and to control the running time of the fuel cell test system; An evaluation unit is used to evaluate the anode's resistance to CO poisoning based on the recovery status of the operating voltage and the recovery status of the high-frequency impedance recorded by the data acquisition unit.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Simple and easy to use: Only a T-junction is needed at the anode inlet, and no additional operations are required during testing, making it very simple and easy to use.

[0017] No modification required to the existing testing system: No hardware modification is required to the fuel cell testing system. The tee interface can utilize the existing pressure testing tee on the anode inlet pipe, without the need for additional installation.

[0018] Low testing cost: No need to modify existing testing systems, and only a fixed concentration is required. The gas mixture is compatible with other tests.

[0019] High test repeatability: The test has high repeatability across multiple tests and high stability during the testing process.

[0020] High test accuracy: The test has high accuracy and reliability, and can distinguish the anti-poisoning ability of anodes with very small differences in preparation parameters.

[0021] High test sensitivity: It can detect minute changes in the anode during the test.

[0022] Shorter testing time: The testing time is shorter while ensuring testing accuracy, about half an hour, while conventional CO toxicity tests usually take more than 1 hour, and some methods even take more than 2 hours.

[0023] The test is highly safe: the gas used is air-fuel mixture, not Using a mixed gas makes the testing process safer.

[0024] High test applicability: It is suitable for different test conditions, such as different battery temperatures and different battery humidity, and can also be used for testing different types of proton exchange membrane fuel cells. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1This is a schematic diagram of the overall architecture of the proton exchange membrane fuel cell anode anti-CO poisoning test system provided in this embodiment of the invention. It shows the seven core modules and their interrelationships, including the fuel cell test system, data acquisition unit, CO gas source, inert gas source, oxygen-containing gas source, control unit, and evaluation unit.

[0027] Figure 2 The flowchart of the CO poisoning resistance test method for proton exchange membrane fuel cell anodes provided in the embodiments of the present invention shows the complete process from activation, recording initial values, instantaneous CO introduction, voltage recovery, impedance recovery to evaluation.

[0028] Figure 3 The graph shown here illustrates the change of operating voltage over time during the testing process provided in this embodiment of the invention, demonstrating the voltage drop, slow recovery process, and the overlap of multiple test curves.

[0029] Figure 4 This is a schematic diagram of the coincidence of the test curves after translation provided in the embodiment of the present invention, showing that the three test curves highly coincide after translation.

[0030] Figure 5 The chart shows a comparison of test curves for different anode samples provided in this embodiment of the invention, demonstrating that this method can distinguish the anti-poisoning ability of two anode samples with similar preparation parameters.

[0031] Figure 6 This is a schematic diagram of the test sensitivity provided in an embodiment of the present invention, demonstrating that the method can detect minute changes or attenuations in the electrode state. Detailed Implementation

[0032] 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.

[0033] The embodiments of this invention are written in a progressive manner.

[0034] Terminology Explanation To facilitate understanding of the technical solution of this invention, some technical terms appearing in the specification are explained as follows: PEMFC (Proton Exchange Membrane Fuel Cell): refers to a power generation device that uses a proton exchange membrane as the electrolyte and hydrogen as fuel to directly convert chemical energy into electrical energy.

[0035] MEA (Membrane Electrode Assembly): refers to the core component of a proton exchange membrane fuel cell, which consists of a proton exchange membrane, an anode catalyst layer, a cathode catalyst layer, and a gas diffusion layer.

[0036] High Frequency Resistance (HFR) refers to the ohmic impedance of a battery measured at a higher frequency using an AC impedance spectrum. It mainly reflects the membrane impedance and contact resistance of the proton exchange membrane.

[0037] CO poisoning refers to the phenomenon where CO impurities in hydrogen fuel adsorb onto the surface of the anode catalyst, occupying catalytic active sites and causing a decline in battery performance.

[0038] Three-way connector: refers to a three-way valve connected to the anode inlet pipe, used for momentary flow during testing. Mixed gas.

[0039] Constant current testing: refers to a test method that operates a fuel cell under a constant current density and monitors the change of cell voltage over time.

[0040] Example 1: System Architecture

[0041] like Figure 1 As shown, this invention provides a CO poisoning resistance testing system for proton exchange membrane fuel cell anodes. Its core lies in achieving CO poisoning resistance performance evaluation without modifying existing testing systems through a three-stage testing process of "pulse poisoning + in-situ recovery + impedance repair." The system adopts a modular architecture, consisting of seven core modules that work collaboratively to achieve a complete closed loop from battery activation to CO poisoning resistance evaluation.

[0042] Specifically, the system includes the following functional modules: The fuel cell testing system provides the fuel cell under test with set operating conditions and operates the fuel cell at a constant current density. This module provides the basic functions required for battery testing, including gas flow control, temperature control, and electronic loads.

[0043] The data acquisition unit records the operating voltage and high-frequency impedance of the fuel cell. This module collects the battery's operating data in real time, providing a data foundation for subsequent evaluation.

[0044] A CO gas source is connected to the fuel cell via a T-junction at the anode inlet, used to instantaneously introduce an excess concentration of CO-containing gas into the anode inlet. The CO gas source provides... The mixture contains a CO concentration at least 20 times higher than that used in conventional CO resistance tests.

[0045] An inert gas source is used to introduce inert gas into the anode for purging. The inert gas is used to purge the anode and remove residual gas.

[0046] An oxygen-containing gas source is used to introduce oxygen-containing gas into the anode. The oxygen-containing gas is used to forcibly restore high-frequency impedance and can be introduced by air backflow or active air introduction.

[0047] The control unit is used to control the on / off timing of the CO gas source, the inert gas source, and the oxygen-containing gas source, and to control the operating time of the fuel cell test system. The control unit performs control according to the following timing sequence: at time t0, the CO gas source is turned on for 0.1 to 10 seconds and then turned off; from t0 to t0 + a second preset time, the CO gas source is kept off; after the data acquisition unit detects that the operating voltage has recovered to the initial voltage (or the stability criterion recognized in the art, such as fluctuation not exceeding ±2% within 1 minute), the inert gas source is turned on to purge for 10 to 60 seconds and then turned off; then the oxygen-containing gas source is turned on for 10 to 60 seconds or until the high-frequency impedance recovers to within ±5% of the initial impedance.

[0048] An evaluation unit is used to evaluate the anode's resistance to CO poisoning based on the recovery status of the operating voltage and the recovery status of the high-frequency impedance recorded by the data acquisition unit.

[0049] The seven functional modules mentioned above work together to form a complete test closed loop. First, the fuel cell test system activates the fuel cell under test to a stable state; the data acquisition unit records the initial operating voltage and initial high-frequency impedance; the control unit controls the CO gas source to instantaneously introduce an excessive concentration of CO-containing gas, causing instantaneous poisoning of the anode; after running for a second preset time, the control unit controls the inert gas source and the oxygen-containing gas source to be introduced sequentially to restore the high-frequency impedance; finally, the evaluation unit evaluates the resistance to CO poisoning based on the collected data.

[0050] All modules exchange data and transmit control commands through well-defined communication interfaces, ensuring the system's scalability and stability. These communication interfaces can be implemented using industry-standard protocols such as RESTful API or Modbus.

[0051] Example 2: General Process

[0052] like Figure 2 As shown, the present invention provides a method for testing the CO poisoning resistance of a proton exchange membrane fuel cell anode, comprising the following steps S1 to S5: S1: Activation and Initial Value Recording The fuel cell is activated to a stable state under set operating conditions and run at a constant current density for a first preset time. The operating voltage of the battery is recorded as the initial voltage, and the high-frequency impedance of the battery is recorded as the initial impedance.

[0053] The purpose of this step is to establish a performance baseline for the battery. The activation process brings the battery to a stable operating state, ensuring the reliability of subsequent test results. In one specific embodiment, the first preset time is 10 minutes, but those skilled in the art will understand that the first preset time can be adjusted within the range of 5 to 30 minutes depending on the battery type and test requirements.

[0054] S2: Instantaneous CO poisoning While maintaining the constant current density, an excessive concentration of CO-containing gas is instantaneously introduced into the anode inlet through a three-way connector connected to the anode inlet and then immediately shut off, causing the anode to be momentarily poisoned. This results in the battery's operating voltage deviating from the initial voltage, and the battery's high-frequency impedance deviating from the initial impedance.

[0055] The core of this step lies in "instantaneous introduction" and "excess concentration." Unlike the continuous introduction of low-concentration CO in existing technologies, this invention uses an instantaneous introduction of high-concentration CO to cause instantaneous poisoning of the anode. In one specific embodiment, the CO-containing gas is... The mixed gas contains 1% CO by volume, which is 200 times the conventional CO concentration of 50 ppm; the introduction time is 3 seconds.

[0056] S3: Operating voltage recovers naturally Continue operating at the constant current density for a second preset time to restore the battery's operating voltage to the initial voltage.

[0057] The purpose of this step is to observe the self-recovery capability of the anode after CO poisoning is stopped. Under a constant current density, as the CO adsorbed on the anode surface is gradually oxidized and desorbed, the operating voltage will slowly recover. In one specific embodiment, the second preset time is 20 minutes, but those skilled in the art will understand that the second preset time can be adjusted within the range of 10 to 60 minutes according to the anode recovery characteristics.

[0058] S4: High-frequency impedance forced recovery After the battery's operating voltage recovers to the initial voltage, inert gas is introduced into the anode for purging, and then oxygen-containing gas is introduced into the anode to restore the battery's high-frequency impedance to the initial impedance.

[0059] In actual testing, it was found that the high-frequency impedance increases instantly upon the introduction of CO. After a constant current test, the battery voltage returns to normal, but the high-frequency impedance is difficult to recover automatically. This step forcibly restores the high-frequency impedance by purging with inert gas and introducing a trace amount of oxygen-containing gas. In one specific embodiment, the inert gas is nitrogen, and the oxygen-containing gas is introduced through a 1-10 minute air backflow.

[0060] S5: Evaluate resistance to CO poisoning The resistance to CO poisoning of the anode is evaluated based on the recovery of the operating voltage and the recovery of the high-frequency impedance. If the operating voltage recovers to within ±2% of the initial voltage within a second preset time, and the high-frequency impedance recovers to within ±5% of the initial impedance after the introduction of oxygen-containing gas, the resistance to CO poisoning of the anode is deemed qualified; otherwise, it is deemed unqualified.

[0061] Example 3: Application of anodic resistance to CO poisoning test The following detailed description, in conjunction with specific embodiments, illustrates the application of this invention in the CO poisoning resistance test of PEMFC anodes.

[0062] Test samples: two PEMFC anti-poisoning anodes with very similar preparation parameters, designated as R30 and R20 respectively.

[0063] Test conditions: Battery temperature set at 80℃, both anode and cathode gases humidified to 100% relative humidity, anode hydrogen flow rate at 1.0 L / min, cathode air flow rate at 2.0 L / min, and constant current density at 0.5 A / cm². 2 .

[0064] Test process: The first step is activation: Activate the battery according to the set activation conditions to fully activate it. Specifically, perform at least 5 activation cycles under the set conditions until the battery's operating voltage and high-frequency impedance tend to stabilize.

[0065] The second step is to adjust the water tank temperature to the set value so that the internal humidity of the battery reaches the set value.

[0066] The third step is to activate the device for at least 5 cycles under the set operating conditions.

[0067] Step 4, 0.5 A / cm 2 Constant current test for 10 minutes: record the initial voltage value and high-frequency impedance value.

[0068] Step 5, quickly introduce CO and then quickly shut off: Close the secondary pressure reducing valve on the cylinder, then open the main pressure reducing valve and close it. Next, open the secondary pressure reducing valve and then sequentially open the three-way valve at the inlet. The air-fuel mixture is shut off after 3 seconds, creating a pressure. The gas mixture is injected into the battery (this pressure can be set to atmospheric pressure - 0.5 MPa). The gas mixture contained 1% CO by volume, which is 200 times the normal CO concentration of 50 ppm. At this point, the battery voltage suddenly dropped and then began to rise slowly.

[0069] Step 6, 0.5 A / cm 2 Constant current test for 20 minutes: to ensure that the poisoned anode can be fully restored.

[0070] Step 7, Nitrogen purging at 1.0 L / min: Nitrogen gas is first introduced at a rate of 1.0 L / min to purge the anode and cathode.

[0071] Step 8: Introduce a small amount of air into the anode: Disconnect the pipeline at the anode outlet of the battery. When the battery voltage drops to 0.7V~0.9V, immediately adjust the nitrogen flow rate at the anode to zero. At this time, the indoor air will flow back to the anode, introducing a small amount of oxygen-containing gas. When the battery voltage drops to 0.3V~0.5V, reconnect the anode outlet pipeline.

[0072] Step 9: Activate the battery under set conditions for more than 5 cycles: restore the high-frequency impedance of the battery to normal and restore the electrodes to their initial state.

[0073] Test results and analysis: like Figure 3 As shown, the same anode sample was subjected to three repeated tests under the same test conditions. The resulting curves showing the change in operating voltage over time are illustrated. Taking the first test as an example, at 0.5 A / cm... 2 After 10 minutes of constant current testing, a sudden current was applied. The mixture caused a sudden drop in battery voltage, which then slowly recovered to its initial value. This was due to the introduction of [unspecified substance] during three tests. The mixing time cannot be guaranteed to be completely consistent, resulting in the test curves not overlapping on the time axis, although the shape and values ​​of the curves are completely identical. For example... Figure 4 As shown, Figure 3 After shifting the three test curves, the curves show a high degree of overlap. Since the curves are only shifted left and right without changing their shape or value, the test curves are essentially highly overlapping, indicating that the test method of this invention has excellent repeatability.

[0074] like Figure 5 As shown in the left figure, the testing method of this invention was used to test PEMFC anti-toxic anodes designated R30 and R20, respectively. The preparation parameters of these two anodes are very similar, making them difficult to distinguish using conventional testing methods. The test curves of the two anodes show slight differences. The right figure, obtained by shifting the left figure, shows a more pronounced difference in the test curves between the two anodes. Therefore, it is evident that the testing method of this invention can distinguish the anti-toxicity capabilities of two anodes with very similar preparation parameters. The tests not only exhibit high overlap but also high discriminative power and accuracy.

[0075] like Figure 6As shown, repeated tests on the same electrode resulted in three phases in the measured curves. In each phase, at least two test curves overlapped, but the distinction between these phases was very small. This indicates a slight change or attenuation in the electrode's state. The testing method of this invention can detect such minute changes in the electrode, demonstrating its high sensitivity.

[0076] comprehensive Figures 3 to 6 The test curve of this invention has the following characteristics: During the poisoning stage, when the substance is instantaneously introduced... After mixing the gas, the battery voltage drops suddenly, and the magnitude of the drop is related to the CO concentration and the introduction time. Due to the use of excessive CO gas, the voltage drop is significant and easy to observe and record. During the recovery phase, the voltage rises slowly during continuous constant current operation. The slope of the recovery curve reflects the self-repair ability of the anode catalyst against CO poisoning and is an important indicator for evaluating its resistance to CO poisoning. During the impedance repair phase, after the working voltage is restored, the high-frequency impedance may not have recovered. By introducing oxygen-containing gas, the high-frequency impedance is restored to its initial value. This process is represented by a brief fluctuation in voltage on the curve.

[0077] Beneficial effects verification The testing method and system provided by this invention have yielded the following beneficial effects through actual testing and verification: 1. Simple to implement and low modification cost This method requires only a three-way connector at the anode inlet (which can be shared with existing pressure testing three-way connectors), without any hardware modification to the fuel cell testing system. The testing operation is simple, requiring only a momentary inflow via the three-way valve. The gas mixture can be poisoned in just 3 seconds, without the need for complex additional equipment. The gas mixing and distribution device significantly reduces the modification cost and operational threshold of testing equipment.

[0078] 2. Short testing time and high efficiency The total testing time for this method is approximately 30 minutes (including 10 minutes of constant current testing and 20 minutes of post-poisoning recovery testing), while conventional CO poisoning tests typically require more than one hour, and some methods even require more than two hours. This method reduces testing time by more than 50%, significantly improving testing efficiency.

[0079] 3. High repeatability and high accuracy like Figures 3 to 5As shown, repeated tests on the same anode sample yielded highly overlapping voltage-time curves (only left and right shifts existed, with identical curve shapes and values), demonstrating the excellent repeatability of this method. Tests on two anode samples (designated R30 and R20) with very similar preparation parameters clearly distinguished their differences in resistance to poisoning, proving the high accuracy and discriminative power of this method.

[0080] 4. High sensitivity like Figure 6 As shown, repeated tests on the same electrode yielded curves that revealed minute changes or attenuations in the electrode state (e.g., the curve showed three stages, with at least two overlapping test curves for each stage, but the distinction between stages was very small), demonstrating that this method has high sensitivity and can detect minute changes in the anode during the test.

[0081] 5. High security The gas used in this method is Gas mixture (e.g., 1% CO + 99%) ), and those used in non-standard tests Mixed gas. The gas mixture is non-flammable, making the entire testing process safer and reducing laboratory safety risks.

[0082] 6. High applicability This method is applicable to different test conditions, including different battery temperatures (e.g., 60℃~80℃) and different battery humidity (e.g., relative humidity 50%~100%). It is also applicable to the anode CO poisoning resistance test of different types of proton exchange membrane fuel cells (e.g., MEAs with different catalyst loadings and membrane thicknesses).

[0083] This invention is applicable not only to catalyst screening and MEA evaluation in laboratory environments, but also to quality control in fuel cell production processes, and has broad application prospects.

[0084] One or more embodiments in this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of this application. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of one or more embodiments in this application should be included within the protection scope of this application.

[0085] If flowcharts are used in this application, they are used to illustrate the operations performed by the system according to embodiments of this application. It should be understood that the preceding or following operations are not necessarily performed in exact order. Instead, the steps can be processed in reverse order or simultaneously. Furthermore, other operations can be added to these flows, or one or more steps can be removed from these flows.

[0086] The foregoing provides a detailed description of a method and system for testing the CO poisoning resistance of a proton exchange membrane fuel cell anode, as provided in this application. The above description of the disclosed embodiments enables those skilled in the art to implement or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for testing the CO poisoning resistance of a proton exchange membrane fuel cell anode, characterized in that, Includes the following steps: The fuel cell was activated to a stable state under set operating conditions and operated at a constant current density for a first preset time. The operating voltage of the battery was recorded as the initial voltage, and the high-frequency impedance of the battery was recorded as the initial impedance. While maintaining the constant current density, an excessive concentration of CO-containing gas is instantaneously introduced into the anode inlet through a three-way connector connected to the anode inlet and then immediately shut off, causing the anode to be momentarily poisoned. This results in the battery's operating voltage deviating from the initial voltage, and the battery's high-frequency impedance deviating from the initial impedance. Continue operating at the constant current density for a second preset time to restore the battery's operating voltage to the initial voltage; After the battery's operating voltage recovers to the initial voltage, inert gas is introduced into the anode for purging, and then oxygen-containing gas is introduced into the anode to restore the battery's high-frequency impedance to the initial impedance. The resistance of the anode to CO poisoning is evaluated based on the recovery of the operating voltage and the recovery of the high-frequency impedance.

2. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, In the excess concentration of CO-containing gas, the concentration of CO is at least 20 times higher than the concentration used in conventional CO resistance tests.

3. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, The evaluation of the anode's resistance to CO poisoning based on the recovery of the operating voltage and the recovery of the high-frequency impedance includes the following steps: First, determine whether the operating voltage recovers to the initial voltage within the second preset time, and obtain a first determination result; The second determination is that the high-frequency impedance recovers to the initial impedance after the oxygen-containing gas is introduced, and a second determination result is obtained. When both the first and second judgment results are yes, the anode is deemed to have qualified resistance to CO poisoning.

4. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, The instantaneous input is a pulse input, with an input time of 0.1 seconds to 10 seconds.

5. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, The oxygen-containing gas is introduced through air backflow or active air introduction.

6. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, Also includes: After evaluating the anode's resistance to CO poisoning based on the recovery of the operating voltage and the recovery of the high-frequency impedance, the following steps are also included: The battery is reactivated under the specified operating conditions for subsequent repeated testing. The reactivation process includes performing at least 5 activation cycles on the battery under the set operating conditions.

7. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 2, characterized in that, The volume fraction of CO is 0.1% to 5%.

8. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, The set operating conditions include at least one of the following test conditions: battery temperature, gas humidity, and gas flow rate.

9. The method for testing the CO poisoning resistance of the anode in a proton exchange membrane fuel cell according to claim 1, characterized in that, The three-way interface is an existing or newly added three-way valve on the anode inlet pipe.

10. A CO poisoning resistance testing system for the anode of a proton exchange membrane fuel cell, characterized in that, include: A fuel cell testing system is used to provide the fuel cell under test with set operating conditions and to operate the fuel cell at a constant current density. The data acquisition unit is used to record the operating voltage and high-frequency impedance of the fuel cell; A CO gas source is connected to the fuel cell via a three-way connector at the anode inlet, and is used to instantaneously introduce an excessive concentration of CO-containing gas into the anode inlet. An inert gas source is used to introduce inert gas into the anode for purging; An oxygen source is used to introduce oxygen-containing gas into the anode; The control unit is used to control the on / off timing of the CO gas source, the inert gas source and the oxygen-containing gas source, and to control the running time of the fuel cell test system; An evaluation unit is used to evaluate the anode's resistance to CO poisoning based on the recovery status of the operating voltage and the recovery status of the high-frequency impedance recorded by the data acquisition unit.

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