Method and equipment for detecting electrochemical active area of fuel cell stack and storage medium

Abstract

The invention discloses a fuel cell stack electrochemical active area detection method, equipment and a storage medium, belongs to the technical field of fuel cells, and solves the problem that detection of the fuel cell stack electrochemical active area based on a constant current method is easily influenced by the above influence factors. On the basis of a constant current method, collected voltage response data are averaged, first-order and second-order differential processing is carried out on the averaged voltage for time so as to determine feature points on a difference curve, corresponding collected voltage values are found according to the feature points on the difference curve, and the collected voltage values are calculated. The electrochemical active area is calculated according to an electrochemical active area formula, the method can be used for testing the electrochemical active area of the electric pile level, the performance evaluation precision of the fuel cell stack can be improved, and a foundation is laid for improving the overall performance and economical efficiency of the fuel cell stack.

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cells and relates to a method, a device and a storage medium for detecting the electrochemical active area of ​​a fuel cell stack. Background Art

[0002] As a highly efficient energy conversion device, fuel cell stacks are widely used in many fields such as electric vehicles, portable energy devices, and fixed power generation systems. The key to the performance of a fuel cell stack lies in the efficiency of its electrochemical reaction, and the electrochemical active area of ​​the fuel cell stack is an important parameter to measure its performance. The electrochemical active area refers to the effective area on the surface of the electrode in the battery stack that can participate in the electrochemical reaction. This area directly affects the power density, energy conversion efficiency, and long-term operation stability of the fuel cell stack.

[0003] The size of the electrochemically active area determines the role that the electrode can play in the chemical reaction, that is, it affects the conversion efficiency of the reactants and the removal efficiency of the products. In practical applications, the larger the electrochemically active area of ​​the fuel cell stack, the stronger its catalytic reaction ability is, which can provide higher power output and better energy conversion efficiency.

[0004] In order to accurately determine the electrochemically active area of ​​a fuel cell stack, existing technologies usually use a variety of measurement techniques including cyclic voltammetry, constant current method, and constant potential method. Among them, the constant current method is widely used because it is simple to operate and can be applied to different types of electrode materials. In the constant current method, the electrochemically active area of ​​the electrode can be derived by applying a constant current during the electrochemical reaction and recording the voltage response. The constant current method can provide quantitative data on the electrode catalytic performance and reaction activity, which is crucial to evaluating and optimizing the overall performance of the fuel cell stack.

[0005] However, in the process of measuring the electrochemical active area of ​​a fuel cell stack using the constant current method, factors such as electrode surface heterogeneity, gas diffusion limitation, different scanning rates, and variations in experimental conditions will affect the accuracy and reliability of the electrochemical active area measurement results. Therefore, how to overcome the above-mentioned problems of the constant current method is particularly important in the measurement of the electrochemical active area of ​​a fuel cell stack. Summary of the invention

[0006] The technical solution of the present invention is used to solve the problem that the electrochemical active area of ​​a fuel cell stack is easily affected by the above-mentioned influencing factors when being detected based on a constant current method.

[0007] The present invention solves the above technical problems through the following technical solutions:

[0008] A method for detecting the electrochemical active area of ​​a fuel cell stack comprises the following steps:

[0009] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell stack to be tested;

[0010] Step 2, the fuel cell stack to be tested operates stably under specified conditions;

[0011] Step 3, after the fuel cell stack under test meets the test conditions, applying a direct current excitation to the fuel cell stack under test, and simultaneously collecting the voltage of each single cell or cell group or the entire stack;

[0012] Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation;

[0013] Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data;

[0014] Step 6: Select the characteristic point of the second-order differential and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I ;

[0015] Step 7, obtain the hydrogen permeation current value I H and double layer capacitance C dl , according to the constant current I ch The collected voltage value is used to calculate the ECSA value.

[0016] Furthermore, the gas under certain conditions is specifically: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases.

[0017] Furthermore, the inert gas is nitrogen, helium or argon.

[0018] Furthermore, the criterion for the stable operation of the fuel cell stack to be tested under specified conditions is that the fluctuation of the voltage collected by any single chip within t1 is not greater than the starting voltage V1.

[0019] Furthermore, the averaging process is the average of voltage values ​​of n adjacent points, where n≥1.

[0020] Furthermore, the following logic is used to represent the electrochemical process after applying DC current excitation to the fuel cell stack under test:

[0021]

[0022] In the formula, I ch Indicates the constant current value applied by the constant current method, I H Indicates the current value generated by the hydrogen permeation process, Q PtIndicates the amount of electricity consumed in the hydrogen desorption process, C dl represents the capacitance of the double layer, ΔV represents the voltage change within a certain time range when a constant current is applied, and R e It represents the short-circuit resistance value caused by the internal short circuit of the electron, t1 represents the stable operation time of the fuel cell stack, t2 represents the time corresponding to the termination voltage, and U represents the collection voltage.

[0023] Furthermore, the expression of the ECSA value is as follows:

[0024]

[0025] Wherein, ECSA represents the electrochemical active area of ​​the catalyst, Γ represents the charge required for the catalyst surface to completely cover the monolayer of adsorbed hydrogen, and M represents the catalyst loading of the electrode being tested.

[0026] An electronic device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the above-mentioned fuel cell stack electrochemical active area detection method, and the processor is configured to execute the program stored in the memory.

[0027] A storage medium stores a computer program, which, when executed by a processor, executes the steps of the above-mentioned method for detecting the electrochemical active area of ​​a fuel cell stack.

[0028] The advantages of the present invention are:

[0029] The present invention is based on the constant current method. The collected voltage response data are averaged, and then the averaged voltage is subjected to first-order and second-order differential processing with respect to time to determine the characteristic points on the differential curve. The corresponding collected voltage values ​​are then found based on the characteristic points on the differential curve. The electrochemically active area is calculated based on the electrochemically active area formula, which can be used for testing the electrochemically active area at the stack level, can improve the performance evaluation accuracy of the fuel cell stack, and lays a foundation for improving the overall performance and economy of the fuel cell stack.

[0030] The present invention accurately measures the hydrogen permeation current and capacitance through an electrochemical workstation or a constant current method, and calculates the electrochemical active area in combination with the voltage data collected under constant current excitation. This method does not rely on a high sampling rate, avoids the problem that the results of traditional linear voltage scanning tests are easily affected by the scanning rate, simplifies the testing process and reduces costs, that is, the test can be completed at a common 10 Hz sampling rate, which also matches the sampling rate commonly used in current testing equipment, thereby simplifying the testing process and reducing costs. It is convenient and economical, and provides a practical solution for the performance evaluation of fuel cell stacks, which has broad application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is a flow chart of a method for detecting electrochemical active area of ​​a fuel cell stack according to a first embodiment of the present invention;

[0032] Figure 2 It is a schematic diagram comparing the electrochemical active area values ​​of the constant current method and the cyclic voltammetry method at a temperature of 70° C. in Example 2 of the present invention;

[0033] Figure 3 Schematic diagram of comparison of electrochemical active area values ​​of constant current method and cyclic voltammetry at a temperature of 70° C. in Example 3 of the present invention;

[0034] Figure 4 It is a schematic diagram of the electrochemical active area data of the fuel cell stack under different temperature conditions of the fourth embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The technical solution of the present invention is further described below in conjunction with the accompanying drawings and specific embodiments:

[0037] Embodiment 1

[0038] like Figure 1 As shown, specifically, a method for detecting the electrochemical active area of ​​a fuel cell stack is disclosed, comprising:

[0039] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell stack to be tested;

[0040] The gas under certain conditions is specifically as follows: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases; the inert gas includes but is not limited to nitrogen, helium, argon, etc., and the certain conditions include temperature, flow, pressure, humidification and other conditions. The specific condition parameters involved in the gas under certain conditions in this embodiment are set according to the actual working conditions that need to be tested.

[0041] In this embodiment, when setting gas conditions for the fuel cell stack to be tested, in order to ensure that the fuel cell stack is in an appropriate working state before measurement, the gas with certain conditions is introduced into the anode and cathode of the fuel cell stack to be tested until the voltage of each fuel cell is reduced to a preset value, thereby providing a conditional basis for subsequent tests.

[0042] Step 2: The fuel cell stack to be tested operates stably under specified conditions. The criterion for stable operation is that the voltage fluctuation of any single chip acquisition within t1 is not greater than the starting voltage V1.

[0043] Step 3: After the fuel cell stack under test meets the test conditions, a DC current excitation I is applied to the fuel cell stack under test. ch , and simultaneously collect the voltage of each single chip, chip group or whole stack;

[0044] In this embodiment, the DC current excitation is that one side of the fuel cell stack under test is connected to the negative electrode of the power supply and the other side is connected to the positive electrode of the power supply. The constant current (load current) applied to the fuel cell stack is I ch .

[0045] Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation;

[0046] In this embodiment, the termination voltage V2 is set to 0.5-0.9V.

[0047] Furthermore, this embodiment may also use a fixed point position of 0.3V to 0.7V as the termination voltage position.

[0048] In this embodiment, after the gas conditions and voltage conditions are adjusted to predetermined values, a preset constant current is applied to the fuel cell stack under test through DC current excitation. During the process of applying the current, the voltage changes of the stack are continuously collected. Once it is observed that the voltage of a single cell reaches the set threshold, the current application is stopped immediately to avoid damage to the stack.

[0049] Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data;

[0050] Furthermore, the averaging process may be an average of voltage values ​​at n adjacent points, where n≥1.

[0051] Step 6: Select the characteristic point of the second-order differential as point N and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I .

[0052] Step 7, using an electrochemical workstation or constant current method to obtain the hydrogen permeation current value I H and double layer capacitance Cdl , the ECSA value is calculated based on the voltage value collected by constant current.

[0053] Furthermore, the electrochemically active area obtained by the test method of this embodiment is compared with the electrochemically active area obtained by the cyclic voltammetry test to verify the accuracy of the test ideas involved in the patent. When performing the cyclic voltammetry test, ensure that the test conditions are consistent with the conditions of this embodiment, the voltage scanning range is set to 0-1.0V (vs RHE), the number of scanning circles is 3 circles, and the cyclic voltammetry scan is performed at different scanning rates, and the integrated area of ​​hydrogen desorption is used as the electrochemically active area value. This embodiment uses cyclic voltammetry for comparative experimental testing, and selects the electrochemically active area obtained when the scanning rate is 0.02V / s as the comparison condition. The test conditions are consistent with the national standards.

[0054] In this embodiment, the following logic is used to represent the electrochemical process corresponding to applying a constant current to the fuel cell stack based on the constant current method:

[0055] Q ch =Q H +Q Pt +Q dl +Q e

[0056] In the formula, Q ch It represents the total amount of electricity generated by the constant current applied by the constant current method, Q H Indicates the amount of electricity consumed during hydrogen permeation, Q Pt represents the amount of electricity consumed in the hydrogen desorption process. In this embodiment, it is mainly the desorption of hydrogen adsorbed on the platinum surface. Q dl Indicates the amount of electricity consumed during the charging process of the double-layer capacitor. In this embodiment, it is related to the voltage change rate. Q e It represents the amount of electricity consumed in the process of internal electronic short circuit, which is mainly caused by the non-insulating property of the film in this embodiment.

[0057] In this embodiment, the constant current method is based on the relationship between current and voltage of electrochemical reactions, and its main theoretical basis includes the following electrochemical processes:

[0058] Hydrogen permeation power consumption Q H : The penetration of hydrogen through battery materials can affect the stability of the electrochemical reaction, resulting in changes in current.

[0059] Power consumption of hydrogen desorption Q Pt :When the electrode voltage changes, hydrogen may desorb from the electrode surface. This process is shown in the curve as a rapid rise in the first-order differential of voltage with respect to time. Hydrogen desorption usually occurs between 0.35V and 0.45V, reflecting the release of hydrogen on the electrode surface.

[0060] Double layer capacitor charge Q dl :The double electric layer formed at the interface between the electrode and the electrolyte will be charged as the voltage changes, and the generated current will affect the rising curve of the first-order differential of voltage with respect to time.

[0061] Electronic internal short circuit power consumption Q e :Electronic short circuit may occur inside the battery. The short circuit current has an important influence on the voltage characteristics of the battery, especially under high current load.

[0062] Furthermore, this embodiment uses the following logic to represent the electrochemical process of the finishing:

[0063]

[0064] In the formula, I ch Indicates the constant current value applied by the constant current method, I H Indicates the current value generated by the hydrogen permeation process, C dl represents the capacitance of the double layer, ΔV represents the voltage change within a certain time range when a constant current is applied, and R e It represents the short-circuit resistance value caused by the internal short circuit of the electron, t1 represents the stable operation time of the fuel cell stack, t2 represents the time corresponding to the termination voltage, and U represents the collection voltage.

[0065] Furthermore, this embodiment uses the following logic to represent the electrochemical active area:

[0066]

[0067] Wherein, ECSA represents the electrochemical active area of ​​the catalyst, Γ represents the charge required for the catalyst surface to completely cover the monolayer of adsorbed hydrogen, and M represents the catalyst loading of the electrode being tested.

[0068] Embodiment 2

[0069] The method for detecting the electrochemical active area of ​​a fuel cell stack provided in this embodiment is specifically as follows:

[0070] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0071] The gas under certain conditions is as follows: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases; the inert gas includes but is not limited to nitrogen, helium, argon, etc. In this embodiment, the reaction area is 300cm 2 Taking a single fuel cell as an example, hydrogen is introduced into the anode and nitrogen is introduced into the cathode. The temperature of the fuel cell is maintained at 70°C and the gas back pressure is 0 kPa.

[0072] Step 2, the fuel cell stack to be tested operates stably under specified conditions. The criterion for stable operation is that the fluctuation of any single-chip collected voltage within t1 is not greater than the starting voltage V1. At this time, the starting voltage is set to 0.1~0.3V, that is, the fluctuation of any single-chip collected voltage within 30s is not greater than 0.1~0.3V.

[0073] Step 3: After the fuel cell stack under test meets the test conditions, a DC current excitation I is applied to the fuel cell stack under test. ch , and simultaneously collect the voltage of each single chip, chip group or whole stack;

[0074] In this embodiment, the DC current excitation is that one side of the fuel cell stack under test is connected to the negative electrode of the power supply and the other side is connected to the positive electrode of the power supply. The constant current (load current) applied to the fuel cell stack is I ch .

[0075] Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation;

[0076] In this embodiment, the termination voltage V2 is set to 0.5-0.9V.

[0077] Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data;

[0078] Furthermore, the averaging process may be the average of voltage values ​​at n adjacent points, where n≥1. In this embodiment, 5 points are averaged, where n=5.

[0079] Step 6: Select the characteristic point of the second-order differential as point N and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I .

[0080] Step 7, using an electrochemical workstation or constant current method to obtain the hydrogen permeation current value I H and double layer capacitance C dl , the ECSA value is calculated based on the voltage value collected by constant current.

[0081] Furthermore, the electrochemically active area obtained by the test method of this embodiment is compared with the electrochemically active area obtained by cyclic voltammetry test to verify the accuracy of the test concept involved in the patent.

[0082] like Figure 2As shown, when performing cyclic voltammetry test, ensure that the test conditions are consistent with the conditions of this embodiment, the voltage scanning range is set to 0-1.0V (vs RHE), the number of scanning circles is 3 circles, and cyclic voltammetry scanning is performed at different scanning rates, and the integrated area of ​​hydrogen desorption is used as the electrochemical active area value. This embodiment uses cyclic voltammetry to perform comparative experimental tests, and selects the electrochemical active area obtained when the scanning rate is 0.02V / s as the comparison condition. Compared with the comparative experimental data, the deviation value of the electrochemical active area is within 5%.

[0083] Embodiment 3

[0084] The method for detecting the electrochemical active area of ​​a fuel cell stack provided in this embodiment is specifically as follows:

[0085] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0086] The gas under certain conditions is as follows: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases; the inert gas includes but is not limited to nitrogen, helium, argon, etc. In this embodiment, the reaction area is 270cm 2 Taking a single fuel cell as an example, hydrogen is introduced into the anode and nitrogen is introduced into the cathode. The temperature of the fuel cell is maintained at 70°C and the gas back pressure is 0 kPa.

[0087] Step 2, the fuel cell stack to be tested operates stably under specified conditions. The criterion for stable operation is that the fluctuation of any single-chip collected voltage within t1 is not greater than the starting voltage V1. At this time, the starting voltage is set to 0.1~0.3V, that is, the fluctuation of any single-chip collected voltage within 30s is not greater than 0.1~0.3V.

[0088] Step 3: After the fuel cell stack under test meets the test conditions, a DC current excitation I is applied to the fuel cell stack under test. ch , and simultaneously collect the voltage of each single chip, chip group or whole stack;

[0089] In this embodiment, the DC current excitation is that one side of the fuel cell stack under test is connected to the negative electrode of the power supply and the other side is connected to the positive electrode of the power supply. The constant current (load current) applied to the fuel cell stack is I ch .

[0090] Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation;

[0091] In this embodiment, the termination voltage V2 is set to 0.5-0.9V.

[0092] Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data;

[0093] Furthermore, the averaging process may be the average of voltage values ​​at n adjacent points, where n≥1. In this embodiment, 5 points are averaged, where n=5.

[0094] Step 6: Select the characteristic point of the second-order differential as point N and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I .

[0095] Step 7, using an electrochemical workstation or constant current method to obtain the hydrogen permeation current value I H and double layer capacitance C dl , the ECSA value is calculated based on the voltage value collected by constant current.

[0096] Furthermore, the electrochemically active area obtained by the test method of this embodiment is compared with the electrochemically active area obtained by cyclic voltammetry test to verify the accuracy of the test concept involved in the patent.

[0097] like Figure 2 As shown, when performing cyclic voltammetry test, ensure that the test conditions are consistent with the conditions of this embodiment, the voltage scanning range is set to 0-1.0V (vs RHE), the number of scanning circles is 3 circles, and cyclic voltammetry scanning is performed at different scanning rates, and the integrated area of ​​hydrogen desorption is used as the electrochemically active area value. Compared with Example 2, the test object in this embodiment is replaced, and the comparative experimental test is also performed using cyclic voltammetry. The electrochemically active area obtained when the scanning rate is 0.02V / s is selected as the comparison condition. Compared with the comparative experimental data, the deviation value of the electrochemically active area is within 1%, and the result of the constant current method test of the electrochemically active area in this embodiment is more accurate and reliable.

[0098] Embodiment 4

[0099] The method for detecting the electrochemical active area of ​​a fuel cell stack provided in this embodiment is specifically as follows:

[0100] Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell to be tested;

[0101] The gas under certain conditions is as follows: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases; the inert gas includes but is not limited to nitrogen, helium, argon, etc. In this embodiment, the reaction area is 300cm 2Taking the 11-piece fuel cell stack as an example, hydrogen was introduced into the anode and nitrogen into the cathode. The fuel cell temperatures were tested at 50°C and 70°C respectively, and the gas back pressure was 0 kPa.

[0102] Step 2, the fuel cell stack to be tested operates stably under specified conditions. The criterion for stable operation is that the fluctuation of any single-chip collected voltage within t1 is not greater than the starting voltage V1. At this time, the starting voltage is set to 0.1~0.3V, that is, the fluctuation of any single-chip collected voltage within 30s is not greater than 0.1~0.3V.

[0103] Step 3: After the fuel cell stack under test meets the test conditions, a DC current excitation I is applied to the fuel cell stack under test. ch , and simultaneously collect the voltage of each single chip, chip group or whole stack;

[0104] In this embodiment, the DC current excitation is that one side of the fuel cell stack under test is connected to the negative electrode of the power supply and the other side is connected to the positive electrode of the power supply. The constant current (load current) applied to the fuel cell stack is I ch .

[0105] Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation;

[0106] In this embodiment, the termination voltage V2 is set to 0.5-0.9V.

[0107] Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data;

[0108] Furthermore, the averaging process may be the average of voltage values ​​at n adjacent points, where n≥1. In this embodiment, 5 points are averaged, where n=5.

[0109] Step 6: Select the characteristic point of the second-order differential as point N and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I .

[0110] Step 7, using an electrochemical workstation or constant current method to obtain the hydrogen permeation current value I H and double layer capacitance C dl , the ECSA value is calculated based on the voltage value collected by constant current.

[0111] like Figure 4The figure shows that the electrochemical active area of ​​the fuel cell stack was tested at different temperatures. It can be seen that as the temperature increases, the electrochemical active area of ​​the fuel cell stack decreases. This conclusion is consistent with the known trend of the electrochemical active area changing with temperature, proving that the constant current method is suitable for the electrochemical active area test at the fuel cell stack level.

[0112] Embodiment 5

[0113] A device includes a memory and a processor, wherein the memory is used to store a program that supports the processor to execute the method for detecting the electrochemical active area of ​​a fuel cell stack in Example 1, 2, 3 or 4, and the processor is configured to execute the program stored in the memory.

[0114] Embodiment 6

[0115] A storage medium stores a computer program, which, when executed by a processor, executes the steps of the method for detecting the electrochemical active area of ​​a fuel cell stack in Embodiments 1, 2, 3 or 4.

[0116] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those 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. However, these 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 invention.

Claims

1. A method for detecting the electrochemical active area of ​​a fuel cell stack, characterized in that: The following steps are involved: Step 1, introducing a gas under certain conditions into the anode and cathode of the fuel cell stack to be tested; Step 2, the fuel cell stack to be tested operates stably under specified conditions; Step 3, after the fuel cell stack under test meets the test conditions, applying a direct current excitation to the fuel cell stack under test, and simultaneously collecting the voltage of each single cell or cell group or the entire stack; Step 4, monitoring the acquisition voltage of any single chip, when it is greater than the termination voltage V2, stopping the DC current excitation; Step 5, averaging the collected voltage data, and performing first-order and second-order time differentials on the averaged voltage data; Step 6: Select the characteristic point of the second-order differential and find the corresponding first-order differential value dV I , and then find the corresponding voltage collection point V I ; Step 7, obtain the hydrogen permeation current value I H and double layer capacitance C dl , according to the constant current I ch The collected voltage value is used to calculate the ECSA value.

2. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 1, characterized in that: The gas under certain conditions is specifically: one side of the fuel cell stack is hydrogen or a mixture of hydrogen and inert gas, the volume concentration of hydrogen in the mixture is not less than 5%, and the other side is a single component inert gas or a mixture of inert gases.

3. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 2, characterized in that: The inert gas is nitrogen, helium or argon.

4. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 1, characterized in that: The criterion for the stable operation of the fuel cell stack to be tested under specified conditions is that the fluctuation of the voltage collected by any single chip within t1 is not greater than the starting voltage V1.

5. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 1, characterized in that: The averaging process is the average of voltage values ​​at n adjacent points, where n≥1.

6. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 1, characterized in that: The following logic is used to represent the electrochemical process after applying DC current excitation to the fuel cell stack under test: In the formula, I ch Indicates the constant current value applied by the constant current method, I H Indicates the current value generated by the hydrogen permeation process, Q Pt Indicates the amount of electricity consumed in the hydrogen desorption process, C dl represents the capacitance of the double layer, ΔV represents the voltage change within a certain time range when a constant current is applied, and R e It represents the short-circuit resistance value caused by the internal short circuit of the electron, t1 represents the stable operation time of the fuel cell stack, t2 represents the time corresponding to the termination voltage, and U represents the collection voltage.

7. The method for detecting the electrochemical active area of ​​a fuel cell stack according to claim 6, characterized in that: The expression of the ECSA value is as follows: Wherein, ECSA represents the electrochemical active area of ​​the catalyst, Γ represents the charge required for the catalyst surface to completely cover the monolayer of adsorbed hydrogen, and M represents the catalyst loading of the electrode being tested.

8. An electronic device, comprising a memory and a processor, characterized in that: The memory is used to store a program that supports the processor to execute the method for detecting the electrochemical active area of ​​a fuel cell stack as described in any one of claims 1 to 7, and the processor is configured to execute the program stored in the memory.

9. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for detecting the electrochemical active area of ​​a fuel cell stack according to any one of claims 1 to 7 are executed.

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