A test method for electrochemical impedance spectroscopy of electrochemical hydrogen compressor

Abstract

A method for testing the electrochemical impedance spectrum of an electrochemical hydrogen compressor relates to the technical field of electrochemical compressors. The method comprises the following steps: connecting a power supply terminal of an electrochemical hydrogen compressor to a power supply, wherein the electrochemical hydrogen compressor uses an activated membrane electrode; introducing reactants under different reaction conditions into the electrochemical hydrogen compressor, applying alternating current to the electrochemical hydrogen compressor, and measuring the electrochemical impedance spectrum of the electrochemical hydrogen compressor, wherein the states of the reactants include pressure, temperature, and stoichiometric ratio of the reactants; analyzing the electrochemical impedance spectrum to obtain the attribution of each part of the electrochemical impedance spectrum, thereby obtaining the operating state of the corresponding components of the electrochemical hydrogen compressor according to the attribution of the electrochemical impedance spectrum, thereby solving the problem of the inability to react in a certain end reaction or a certain specific component of a traditional electrochemical hydrogen compressor that uses a simple current-voltage curve for performance evaluation.

Description

Technical Field

[0001] The present application belongs to the technical field of electrochemical compressors, and in particular, relates to a method for testing an electrochemical impedance spectrum of an electrochemical hydrogen compressor. Background Art

[0002] The working principle of the electrochemical hydrogen compressor is to convert electrical energy into compression energy through electrochemical reactions. As an important branch in the field of fuel cells, it has the outstanding advantages of fast start-up speed at room temperature, small size, modularization, noiseless operation, hydrogen purification, no electrolyte loss, easy drainage, long life, and low energy consumption. Therefore, the electrochemical hydrogen compression device has a very broad application prospect. Further understanding of the internal hydrogen electrode reaction state of the electrochemical hydrogen compressor is conducive to promoting the development of technology, and to understand the operating status in real time, providing a reference for technicians. The test method of electrochemical impedance spectroscopy is to analyze the kinetics of the hydrogen electrode process by applying a small amplitude AC signal with different frequencies.

[0003] At present, the existing technology has too little description about electrochemical hydrogen compressors, and there is no detailed overview of the effects of intake pressure, temperature, stoichiometric ratio on its performance, as well as the charge transfer between the anode and cathode. The existing technology mostly uses simple current-voltage curves for performance evaluation, and fails to deeply explore the effects of performance degradation on the electrochemical reactions at the two poles (anode and cathode) of the electrochemical hydrogen compressor (charge transfer, whether mass transfer resistance occurs, etc.). A single current-voltage curve cannot reflect the problem occurring in a certain end reaction or a specific component.

[0004] Therefore, the traditional technical solution has the problem that the electrochemical hydrogen compressor uses a simple current-voltage curve to evaluate its performance and cannot reflect the problem that the problem occurs at a certain end reaction or a certain specific component. Summary of the invention

[0005] The purpose of the present application is to provide a test method for the electrochemical impedance spectroscopy of an electrochemical hydrogen compressor, aiming to solve the problem of non-reaction occurring at a certain end reaction or a certain specific component in traditional electrochemical hydrogen compressors that use a simple current-voltage curve for performance evaluation.

[0006] The first aspect of the embodiment of the present application provides a method for testing the electrochemical impedance spectroscopy of an electrochemical hydrogen compressor, comprising the following steps:

[0007] S1. Connecting the anode of the electrochemical hydrogen compressor to the positive electrode of a power source, and connecting the cathode of the electrochemical hydrogen compressor to the negative electrode of the power source, wherein the positive electrode of the power source is a working electrode, and the negative electrode of the power source is a reference electrode;

[0008] S2, passing reactants under different reaction conditions into the electrochemical hydrogen compressor, applying alternating current to the electrochemical hydrogen compressor through the power supply, and measuring the electrochemical impedance spectrum of the electrochemical hydrogen compressor, and obtaining multiple electrochemical impedance spectra through multiple measurements; the reaction conditions include: pressure, temperature and reactant dosage ratio;

[0009] S3. Analyze the plurality of electrochemical impedance spectra to obtain the attribution of each part of the electrochemical impedance spectra, and thereby obtain the operating status of the corresponding parts of the electrochemical hydrogen compressor according to the attribution of the electrochemical impedance spectra.

[0010] Preferably, the electrochemical hydrogen compressor is one of a single-electrode electrochemical hydrogen compressor and a multi-stack electrochemical hydrogen compressor.

[0011] Preferably, in S2, the power supply applies a small-amplitude sinusoidal voltage or current to the electrochemical hydrogen compressor as a disturbance signal, wherein when the current is applied, the upper and lower disturbances of the current value are set to 1 to 20%.

[0012] Preferably, the scanning frequency of the electrochemical impedance spectrum in measuring the electrochemical impedance spectrum of the electrochemical hydrogen compressor is 0.01 Hz-100 kHz.

[0013] Preferably, the variable AC amplitude in the electrochemical impedance spectrum of the electrochemical hydrogen compressor is measured to be 10% of the DC value.

[0014] Preferably, the reactant uses hydrogen with different stoichiometric ratios and different humidity.

[0015] Preferably, the membrane electrode of the electrochemical hydrogen compressor is an activated membrane electrode.

[0016] Preferably, the testing method further comprises: arranging the negative electrode of the power supply on the outside of the membrane electrode of the electrochemical hydrogen compressor, inside or at the end of the flow field plate.

[0017] Compared with the traditional current-voltage curve, the current-voltage curve can only obtain instantaneous performance through fast linear scanning, or determine the performance through data collected over a long period of time in constant current or constant voltage mode. The current-voltage curve under these two operations cannot accurately reflect the operating state of the instantaneous electrochemical hydrogen compressor. It can only evaluate the performance of the entire electrochemical hydrogen compressor as a whole, and cannot determine the changes in components such as the membrane electrode during the reaction. Under actual real-time working conditions, the reference for judging the operating state is far less than that of the electrochemical reactance. Therefore, the beneficial effects of the embodiments of the present invention compared with the prior art are:

[0018] 1. The above-mentioned test method of the electrochemical impedance spectrum of the electrochemical hydrogen compressor is as follows: the anode of the electrochemical hydrogen compressor is connected to the positive electrode of the power supply, the cathode of the electrochemical hydrogen compressor is connected to the negative electrode of the power supply, the positive electrode of the power supply is the working electrode, and the negative electrode of the power supply is the reference electrode or the comparison electrode; reactants under different reaction conditions are introduced into the electrochemical hydrogen compressor, AC disturbance is applied to the electrochemical hydrogen compressor, and the electrochemical impedance spectrum of the electrochemical hydrogen compressor is measured, and multiple electrochemical impedance spectra are obtained through multiple measurements; the reaction conditions include: pressure, temperature and reactant dosage ratio; multiple electrochemical impedance spectra are analyzed to obtain the attribution of each part of the electrochemical impedance spectrum, and thus the operating status of the corresponding components of the electrochemical hydrogen compressor is obtained according to the attribution of the electrochemical impedance spectrum, thereby solving the problem of the inability to react in a certain end reaction or a specific component of the traditional electrochemical hydrogen compressor using a simple current-voltage curve for performance evaluation.

[0019] 2. In the above-mentioned test method of electrochemical impedance spectroscopy of electrochemical hydrogen compressor, during the process of hydrogen pumping by chemical hydrogen compressor, the status of the in-situ reaction device can be detected in real time through data, providing a rapid, reasonable and effective basis for judging the operating status.

[0020] 3. In the above-mentioned test method of electrochemical impedance spectroscopy of electrochemical hydrogen compressor, after a large amount of test data is accumulated, the electrochemical impedance spectrum obtained by measurement can be analyzed, and the real part, imaginary part, amplitude, phase angle and other data of electrochemical impedance can be quickly fitted to obtain accurate data comparison, and the operating status such as internal temperature or internal humidity can be quickly estimated in reverse through the characteristic information in the electrochemical impedance spectrum without adding or changing any mechanical structure.

[0021] 4. In the above-mentioned test method for electrochemical impedance spectroscopy of an electrochemical hydrogen compressor, the electrochemical hydrogen compressor includes an electrochemical hydrogen compressor with a single electrode and a multi-stacked electrochemical hydrogen compressor, that is, the test method is applied to an electrochemical hydrogen compressor with multiple stacks to replace the cost of sensor testing, etc.

[0022] 5. The above-mentioned test method of electrochemical impedance spectroscopy of an electrochemical hydrogen compressor can also be used to test a separate single electrochemical hydrogen compressor, thereby further separating the resistance of each part and observing the status of each part of the electrochemical hydrogen compressor. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a flow chart of the testing method of electrochemical impedance spectroscopy of the electrochemical hydrogen compressor of the present invention;

[0024] Figure 2 It is a schematic diagram of the experimental device structure of the electrochemical hydrogen compressor of the present invention;

[0025] Among them, 1. Hydrogen intake device; 2. Temperature control device; 3. Electrochemical hydrogen compressor; 4. Electrochemical impedance spectroscopy measurement device; 5. Computer;

[0026] Figure 3 The electrochemical hydrogen compressor circuit model that is the basis of the present invention;

[0027] Figure 4 is an electrochemical impedance spectrum diagram of the first embodiment of the present invention;

[0028] Figure 5 is an electrochemical impedance spectrum diagram of the second embodiment of the present invention;

[0029] Figure 6 This is an electrochemical impedance spectrum diagram of the third embodiment of the present invention. DETAILED DESCRIPTION

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0031] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0032] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0033] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0034] Figure 2A schematic diagram of the structure of an experimental device of an electrochemical hydrogen compressor provided in a preferred embodiment of the present application is shown. For the sake of convenience of explanation, only the parts related to the present embodiment are shown, which are described in detail as follows: The experimental device of the electrochemical hydrogen compressor includes: a hydrogen intake device, a temperature control device, an electrochemical hydrogen compressor, an electrochemical impedance spectroscopy measuring device and a computer. The hydrogen intake device transmits hydrogen to the temperature control device. By controlling the hydrogen intake device and the temperature control device, hydrogen with different pressure states, temperature states and stoichiometric ratios can be obtained; the temperature control device transmits the proportioned hydrogen to the chemical hydrogen compressor, and the electrochemical impedance spectroscopy measuring device performs electrochemical impedance spectroscopy measurement on the chemical hydrogen compressor, and the measured data is stored and analyzed by the computer.

[0035] Figure 1 A flow chart of a method for testing an electrochemical impedance spectroscopy of an electrochemical hydrogen compressor provided in a preferred embodiment of the present application is shown. The testing method comprises the following steps:

[0036] S1. Connect the anode of the electrochemical hydrogen compressor to the positive electrode of the power supply, connect the cathode of the electrochemical hydrogen compressor to the negative electrode of the power supply, and power the electrochemical hydrogen compressor through the power supply; the positive electrode of the power supply is the working electrode, and the negative electrode of the power supply is the reference electrode or the comparison electrode; wherein the electrochemical hydrogen compressor uses an activated membrane electrode;

[0037] The anode of the electrochemical hydrogen compressor is the electrode at the end where hydrogen enters. When the reaction occurs, hydrogen is oxidized into hydrogen ions, releasing two electrons.

[0038] Membrane Electrode Assembly (MEA) is the core component of the electrochemical hydrogen compressor, including the anode, cathode and the proton exchange membrane sandwiched between the anode and cathode. In fact, during the preparation of the membrane electrode, part of the active surface of the catalyst in the anode catalyst layer will be covered by the perfluorosulfonic acid resin (Nafion); when coating to form the catalyst layer, the pores in the layer may be blocked; and the hot pressing process also causes further blockage of the pores in the catalyst layer, which makes it impossible for the anode reaction gas to reach the catalyst surface. In addition, the proton exchange membrane in the prepared membrane electrode is dry and cannot effectively transport protons. The catalyst may also be not fully activated or there is catalyst poisoning due to impurities or other reasons. In order to enable the fuel cell stack to reach or the membrane electrode quickly reach the optimal working state, and to improve the utilization rate of the catalyst in the membrane electrode, the membrane electrode of the initial fuel cell stack needs to be activated. Therefore, the performance of the activated membrane electrode is better than that of the unactivated membrane electrode. Therefore, the activated membrane electrode is used for testing.

[0039] S2. Reactants under different reaction conditions are introduced into the electrochemical hydrogen compressor, and alternating current is applied to the electrochemical hydrogen compressor to place the electrochemical hydrogen compressor under various current density or voltage conditions. The electrochemical impedance spectrum of the electrochemical hydrogen compressor is measured by an electrochemical impedance spectrum testing device, and multiple electrochemical impedance spectra are obtained through multiple measurements; wherein the electrochemical hydrogen compressor is supplied with a constant voltage or a constant current through a main power supply so that the electrochemical hydrogen compressor can operate normally; the reaction conditions include: pressure, temperature, and the stoichiometric ratio of the reactants;

[0040] Specifically, the reactants use hydrogen with different stoichiometric ratios and different humidity. The reactants use hydrogen with different stoichiometric ratios and humidity, which is transported to the temperature control device through a hydrogen intake device to obtain corresponding hydrogen with different stoichiometric ratios and humidity, and then transported to the electrochemical hydrogen compressor through the temperature control device; the temperature control device uses a temperature-controllable temperature box, etc.

[0041] The power supply applies a small-amplitude sinusoidal voltage or current as a disturbance signal to the electrochemical hydrogen compressor, wherein when a small-amplitude sinusoidal current is used, the disturbance current can set the upper and lower disturbances of the current value (the upper and lower limits of the current value) by 1 to 20%; the electrochemical impedance spectroscopy can obtain different reactions of the electrode within different frequency ranges. In order to make the measured data more accurate, it is necessary to determine the relationship between the characteristic quantities of the electrochemical impedance spectroscopy and the environmental parameters within different scanning frequency ranges. Therefore, in S3, the scanning frequency is 0.01Hz-100kHz; the variable AC amplitude is 10% of the DC value.

[0042] For example, three electrochemical impedance spectra are measured, including electrochemical impedance spectra 1, electrochemical impedance spectra 2 and electrochemical impedance spectra 3. The average of the three electrochemical impedance spectra is calculated to make the data more accurate, which serves as a basis for subsequent data processing.

[0043] S3. Analyze multiple electrochemical impedance spectra by computer to obtain the attribution of each part of the electrochemical impedance spectrum, and then obtain the operating status of the corresponding parts of the electrochemical hydrogen compressor according to the attribution of the electrochemical impedance spectrum.

[0044] Exemplarily, the electrochemical hydrogen compressor may be a single-electrode electrochemical hydrogen compressor or a multi-stack electrochemical hydrogen compressor.

[0045] Step S3 is as follows:

[0046] According to multiple electrochemical impedance spectra, the corresponding circuit model based on the electrochemical hydrogen compressor is obtained, and then the corresponding impedance (which is also a parameter of the electrochemical impedance spectrum) is calculated based on the electrochemical hydrogen compressor circuit model. According to the characteristic quantity of the impedance, the internal electrode reaction process of the electrochemical hydrogen compressor during the electrochemical reaction, the operating state of the electrochemical hydrogen compressor, etc. are obtained by calculation and analysis; the characteristic quantity includes: the real part, imaginary part, amplitude, phase angle of the impedance or a function containing the corresponding impedance parameters, and one or more characteristic quantities can be selected for analysis as needed. Therefore, the present invention can study the kinetic parameters related to the hydrogen electrode reaction by using the electrochemical impedance spectrum, and can monitor the ohmic resistance, diffusion resistance, bipolar reaction charge transfer resistance, etc. in the electrochemical hydrogen compressor in real time in situ according to the test data and the calculation based on the electrochemical hydrogen compressor circuit model.

[0047] The circuit model of the electrochemical hydrogen compressor can use the classical model or design the corresponding equivalent circuit model based on the electrochemical hydrogen compressor used for the test. Figure 3 As shown, Figure 3 Figures (a) and (b) in the figure are two electrochemical hydrogen compressor circuit models. The electrochemical hydrogen compressor circuit models include components such as equivalent resistance (R), equivalent capacitance (Cpea), inductance (Cpec) based on the electrochemical hydrogen compressor circuit model. The components are combined in series or parallel.

[0048] Figure 4 In the high frequency region of the electrochemical impedance spectrum, the ohmic resistance related to the passage of hydrogen ions and electrons through the proton exchange membrane, catalyst layer, gas diffusion layer, flow field plate, wire, etc., is represented by a point on the electrochemical impedance spectrum, represented by a resistance element R Ω Conduct simulations;

[0049] In the medium and high frequency region of the electrochemical impedance spectrum, the charge transfer process of the anode end hydrogen being oxidized to hydrogen ions through the catalytic layer and the hydrogen ions being reduced to hydrogen at the cathode has two related semicircles on the electrochemical impedance spectrum. In the circuit equivalent model, the structures related to the charge transfer process are represented by a constant phase angle element CPE. a and a resistor R a Parallel circuit to simulate, or series with a constant phase angle CPE c and a resistor R c Parallel circuits to simulate;

[0050] In the low-frequency region of the electrochemical impedance spectrum, the diffusion process of hydrogen ions inside the active material particles is a slant line on the electrochemical impedance spectrum. In the circuit equivalent model, the Weber impedance element W is used to simulate it. Since the lack of gas occurs at the anode, W is proportional to the anode resistance R. a Series connection.

[0051] The equivalent circuit model is a description of the kinetics of the electrode (cathode and anode) reaction process of the electrochemical hydrogen compressor, in which the elements of the equivalent circuit model correspond to the elements related to the electrode reaction process, and the response of the equivalent circuit model includes the structure and property information of the electrode reaction process. The process of equivalent circuit modeling is a heuristic method. According to the operating principle of the electrochemical hydrogen compressor, that is, the electrode reaction-related kinetic parameters, the electrode reaction-related elements and the relationship between the elements, and the impedance response information of the electrochemical impedance spectrum (corresponding electrode reaction characteristics and other information), multiple equivalent circuits are constructed, and the correlation and adaptability between multiple equivalent circuits and the actual electrode reaction process are analyzed and verified, and doubtful models are eliminated to establish effective models.

[0052] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0053] After a large number of tests based on the test method of electrochemical impedance spectroscopy of electrochemical hydrogen compressors, a large amount of test data has been accumulated, and the internal temperature or internal humidity and other operating conditions can be quickly estimated through the characteristic information in the electrochemical impedance spectrum without adding or changing any mechanical structure. For example, temperature can be replaced by thermocouples to obtain temperature data inside the electrochemical hydrogen compressor.

[0054] In addition, the electrochemical impedance spectroscopy test method of the electrochemical hydrogen compressor can also test a separate single electrochemical hydrogen compressor, for example, by adding a reference electrode to the inside of the proton exchange membrane, the inside of the gas diffusion layer, the inside of the flow field plate or the end for testing.

[0055] In one of the embodiments, in step S1, the anode flow field plate of the electrochemical hydrogen compressor is connected to the positive electrode of the power supply, the cathode flow field plate of the electrochemical hydrogen compressor is connected to the negative electrode of the power supply, and the membrane electrode of the electrochemical hydrogen compressor is an activated membrane electrode; then testing is performed according to steps S2-S3, and the diffusion loss situation can be analyzed through the obtained electrochemical impedance spectrum.

[0056] In one of the embodiments, in step S1, the outer side of the anode of the membrane electrode of the electrochemical hydrogen compressor is connected to the positive electrode of the power supply, and the outer side of the cathode of the membrane electrode of the flow field plate of the electrochemical hydrogen compressor is connected to the negative electrode of the power supply, and the membrane electrode of the electrochemical hydrogen compressor is an activated membrane electrode; then, testing is performed according to steps S2-S3, and the diffusion condition of the membrane electrode can be analyzed through the obtained electrochemical impedance spectrum.

[0057] The working principle of the electrochemical impedance spectroscopy test method of the electrochemical hydrogen compressor of the present invention is described in detail so that those skilled in the art can better understand the present invention:

[0058] The following examples are intended to illustrate rather than limit the invention. The examples are described using the real and imaginary parts of the electrochemical impedance spectrum, where Z' is the real part of the electrochemical impedance spectrum and Z" is the imaginary part of the electrochemical impedance spectrum.

[0059] The test was conducted using hydrogen with different stoichiometric ratios and the same temperature, humidity and pressure. For example, the hydrogen with stoichiometric ratios of (1.2, 1.6, 2.0), temperature of 30°C, humidity of RH=100%, and inlet pressure of 30 kPa was applied to the electrochemical hydrogen compressor at 1.5 A / cm 2 The test was carried out under the condition of current density, and the electrochemical impedance spectrum was measured as follows Figure 4 As shown, by comparing different ohmic resistances through the intersection of the real axis of the electrochemical impedance spectrum, combined with the above-mentioned method of analyzing multiple electrochemical impedance spectra, the electrochemical impedance simulation software is used to model and further calculate the anode and cathode charge transfer impedance and mass transfer impedance of the electrochemical hydrogen compressor. Whether the gas supply is sufficient is mainly reflected in the first semicircle of the electrochemical impedance spectrum, through Figure 4 It can be seen from the electrochemical impedance spectrum that the anode charge transfer of the electrochemical hydrogen compressor with a gas supply stoichiometric ratio lower than 1.4 is limited.

[0060] The test was conducted with hydrogen at different temperatures and the same stoichiometric ratio, humidity and pressure. The intake temperature and the operating temperature of the electric compressor were different, and the humidity was controlled differently. For example, the intake temperature was (30°C, 50°C, 70°C, 90°C), the stoichiometric ratio was 1.6, the humidity was RH=100%, the battery temperature was 30°C, and the intake pressure was 50kPa. The current density applied to the electrochemical hydrogen compressor was 0.2A / cm 2 The electrochemical impedance spectrum was obtained under the conditions of Figure 5 As shown, through Figure 5 It can be seen that ohmic resistance is mainly affected by temperature. Figure 4 From the electrochemical impedance spectrum, we can see that the temperature influence is mainly reflected in the real part of the electrochemical impedance spectrum, but it is not limited to the real part. By continuously observing and analyzing the ohmic impedance of the inner membrane electrode of the electrochemical hydrogen compressor, we can judge whether there is dryness or flooding, and the anode charge transfer is affected by different humidity.

[0061] Under the conditions of applying different current densities to the electrochemical hydrogen compressor, the hydrogen with the same stoichiometric ratio, temperature, humidity and pressure was tested. For example, the hydrogen with a stoichiometric ratio of 1.2, a temperature of 30°C, a humidity of 100%, and an inlet pressure of 50 kPa was applied to the electrochemical hydrogen compressor with different current densities (0.2 A / cm 2 , 1.0A / cm 2 , 2.5A / cm2 ) was tested under the conditions of Figure 6 As shown, at 0.2A / cm 2 Under low current, the electrochemical hydrogen compressor has a better water absorption degree, at 1.0A / cm 2 The humidity of the lower anode air intake is suitable for this working condition, the ohmic impedance is small, and the charge transfer speed is significantly accelerated with the increase of current density. 2 The large electroosmotic effect causes the cathode water content to be too high, blocking the reaction active sites and resulting in obvious mass transfer resistance.

[0062] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0063] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor, characterized in that: The following steps are involved: S1. Connecting the anode of the electrochemical hydrogen compressor to the positive electrode of a power source, and connecting the cathode of the electrochemical hydrogen compressor to the negative electrode of the power source, wherein the positive electrode of the power source is a working electrode, and the negative electrode of the power source is a reference electrode; S2, passing reactants under different reaction conditions into the electrochemical hydrogen compressor, applying alternating current to the electrochemical hydrogen compressor through the power supply, and measuring the electrochemical impedance spectrum of the electrochemical hydrogen compressor, and obtaining multiple electrochemical impedance spectra through multiple measurements; the reaction conditions include: pressure, temperature and reactant dosage ratio; the reactants are hydrogen with different stoichiometric ratios and different humidity; S3. Analyze the plurality of electrochemical impedance spectra to obtain the attribution of each part of the electrochemical impedance spectra, and thereby obtain the operating status of the corresponding parts of the electrochemical hydrogen compressor according to the attribution of the electrochemical impedance spectra.

2. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The electrochemical hydrogen compressor is a single-electrode electrochemical hydrogen compressor or a multi-stack electrochemical hydrogen compressor.

3. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: In S2, the power supply applies a small-amplitude sinusoidal voltage or current to the electrochemical hydrogen compressor as a disturbance signal, wherein when applying the current, the upper and lower disturbances of the current value are set to 1-20%.

4. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The scanning frequency of the electrochemical impedance spectrum in measuring the electrochemical impedance spectrum of the electrochemical hydrogen compressor is 0.01 Hz-100 kHz.

5. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The variable AC amplitude in the electrochemical impedance spectrum of the electrochemical hydrogen compressor is measured to be 10% of the DC value.

6. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The reactant uses hydrogen with different stoichiometric ratios and different humidity.

7. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The membrane electrode of the electrochemical hydrogen compressor is an activated membrane electrode.

8. The method for testing electrochemical impedance spectroscopy of an electrochemical hydrogen compressor according to claim 1, characterized in that: The testing method further includes: arranging the negative electrode of the power supply on the outside of the membrane electrode of the electrochemical hydrogen compressor, inside or at the end of the flow field plate.

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