Fuel cell local electrochemical impedance spectroscopy test system and test method

Abstract

This application relates to the field of fuel cell technology, and particularly to a local electrochemical impedance spectroscopy (FET) testing system and method for fuel cells. The method includes: acquiring the total input current of the test object under preset test conditions, as well as voltage and current time-domain data for multiple zones within the target membrane electrode area; correcting the voltage time-domain data according to a preset equivalent contact resistance value to obtain corrected voltage time-domain data; converting the corrected voltage and current time-domain data to the frequency domain to extract the amplitude and phase of the current and voltage in multiple zones, generating FET test results for multiple zones. This application can effectively eliminate the influence of contact voltage drop on local voltage readings in the measurement circuit, significantly improving the authenticity and comparability of local impedance data. Simultaneously, through a parallel impedance inversion verification method, a quantitative correlation is established between local impedance measurement and overall impedance response, enhancing the physical reliability of the test results.

Description

Technical Field

[0001] This application relates to the field of fuel cell technology, and in particular to a local electrochemical impedance spectroscopy testing system and method for fuel cells. Background Technology

[0002] During actual operation, proton exchange membrane fuel cells (PEMFCs) undergo complex heat and mass transfer processes. The electrochemical reaction state within the effective reaction region of the membrane electrode assembly is non-uniform, leading to local differences in the distribution of key physical fields, such as local current density, local temperature, and local water content. Electrochemical impedance spectroscopy (EIS), as an online testing and characterization technique, can analyze various voltage losses within the fuel cell.

[0003] In related technologies, traditional electrochemical impedance spectroscopy testing is mostly performed on single cells and single or multiple single cells in fuel cell stacks. It uses embedded sensor arrays to measure the distribution of local current density or temperature, and tests and characterizes the distribution of current density and temperature inside the fuel cell.

[0004] However, traditional electrochemical impedance spectroscopy (EIS) in related technologies can only obtain overall averaged information to obtain the overall electrochemical performance of the fuel cell, but it cannot analyze the local membrane electrode assembly inside the fuel cell. This results in a lack of analysis of the local distribution characteristics of the fuel cell, and the local signal deviates from the overall excitation in terms of timing. This seriously affects the accuracy and repeatability of impedance calculation, and restricts the development of fuel cell testing, diagnosis and performance optimization, which urgently needs to be solved. Summary of the Invention

[0005] This application provides a local electrochemical impedance spectroscopy testing system and method for fuel cells, which solves the problems in the related technology that traditional electrochemical impedance spectroscopy testing cannot analyze the local membrane electrode inside the fuel cell, resulting in a lack of analysis of the local distribution characteristics of the fuel cell, and the time sequence deviation between the local signal and the overall excitation, which seriously affects the accuracy and repeatability of impedance calculation, and restricts the development of fuel cell testing, diagnosis and performance optimization.

[0006] A first aspect of this application provides a fuel cell local electrochemical impedance spectroscopy testing system, comprising: a workstation for sending a digital trigger signal and applying an AC excitation signal within a preset frequency range to a test object; a sensor array disposed inside the test object for capturing current response signals and voltage response signals of multiple zones within the membrane electrode region of the test object according to the AC excitation signal; and a data acquisition module for acquiring current response signals and voltage response signals of multiple zones within the membrane electrode region after receiving the digital trigger signal, so as to obtain electrochemical impedance spectroscopy test results of multiple zones corresponding to the membrane electrode of the test object; wherein the general-purpose input / output port of the workstation and the external trigger pin of the data acquisition module are connected by a preset two-port cable.

[0007] A second aspect of this application provides a method for testing local electrochemical impedance spectroscopy (TIS) of a fuel cell, employing the aforementioned fuel cell local electrochemical impedance spectroscopy testing system. The method includes the following steps: acquiring the total input current of the test object under preset test conditions, and voltage time-domain data and current time-domain data of multiple zones within the target membrane electrode region of the test object; correcting the voltage time-domain data according to a preset equivalent contact resistance value to obtain corrected voltage time-domain data; converting the corrected voltage time-domain data and current time-domain data to the frequency domain to extract the current and its corresponding amplitude and phase of the multiple zones, as well as the voltage and its corresponding amplitude and phase of the multiple zones; and generating electrochemical impedance spectroscopy test results for the multiple zones based on the current and its corresponding amplitude and phase of the multiple zones and the voltage and its corresponding amplitude and phase of the multiple zones.

[0008] Optionally, in one embodiment of this application, acquiring the total input current of the item under test under preset test conditions, and the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode region of the item under test, includes: applying a target DC load to the item under test, and superimposing an AC excitation signal within a preset frequency range onto the target DC load; and determining the total input current of the item under test and the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode region of the item under test under the preset test conditions, while superimposing the target DC load and the AC excitation signal onto the item under test.

[0009] Optionally, in one embodiment of this application, before correcting the voltage time-domain data according to the preset equivalent contact resistance value, the method further includes: applying a target current to the current signal measurement circuit of the test object, obtaining the voltage drop of the target current across the circuit parasitic resistance of the current signal measurement circuit; obtaining the overall equivalent contact resistance value of the current signal measurement circuit based on the voltage drop, and determining the preset equivalent contact resistance value based on the overall equivalent contact resistance value.

[0010] Optionally, in one embodiment of this application, after generating the electrochemical impedance spectroscopy test results for multiple partitions, the method further includes: calculating the electrochemical impedance spectra of multiple partitions in parallel to generate a Nyquist plot of the overall impedance corresponding to the membrane electrode; comparing the Nyquist plot of the overall impedance with a preset Nyquist plot of the overall impedance, and generating a verification result of the electrochemical impedance spectroscopy test results for multiple partitions based on the comparison result.

[0011] A third aspect of this application provides a local electrochemical impedance spectroscopy (HISS) testing device for a fuel cell, comprising: a first acquisition module, configured to acquire the total input current of a test object under preset test conditions, and voltage time-domain data and current time-domain data of multiple partitions within a target membrane electrode region of the test object; a correction module, configured to correct the voltage time-domain data according to a preset equivalent contact resistance value to obtain corrected voltage time-domain data, and convert the corrected voltage time-domain data and current time-domain data to the frequency domain to extract the current and its corresponding amplitude and phase of the multiple partitions, and the voltage and its corresponding amplitude and phase of the multiple partitions; and a generation module, configured to generate electrochemical impedance spectroscopy test results of the multiple partitions based on the current and its corresponding amplitude and phase of the multiple partitions and the voltage and its corresponding amplitude and phase of the multiple partitions.

[0012] Optionally, in one embodiment of this application, the first acquisition module includes: a testing unit, configured to apply a target DC load to the test object and superimpose an AC excitation signal within a preset frequency range onto the target DC load; and a determining unit, configured to determine the total input current of the test object under the preset test conditions and the voltage time-domain data and current time-domain data of multiple partitions within the target membrane electrode region of the test object, when the target DC load and the AC excitation signal are superimposed on the test object.

[0013] Optionally, in one embodiment of this application, it further includes: a second acquisition module, configured to apply a target current to the current signal measurement circuit of the test item before correcting the voltage time-domain data according to a preset equivalent contact resistance value, and acquire the voltage drop of the target current across the circuit parasitic resistance of the current signal measurement circuit; and a determination module, configured to obtain the overall equivalent contact resistance value of the current signal measurement circuit based on the voltage drop, so as to determine the preset equivalent contact resistance value based on the overall equivalent contact resistance value.

[0014] Optionally, in one embodiment of this application, it further includes: a calculation module, used to calculate the electrochemical impedance spectra of the multiple partitions in parallel after generating the electrochemical impedance spectroscopy test results of the multiple partitions, and generate the overall impedance Nyquist plot corresponding to the membrane electrode; and a comparison module, used to compare the overall impedance Nyquist plot with a preset overall impedance Nyquist plot, and generate a verification result of the electrochemical impedance spectroscopy test results of the multiple partitions based on the comparison result.

[0015] A fourth aspect of this application provides an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the fuel cell local electrochemical impedance spectroscopy testing method as described in the above embodiments.

[0016] A fifth aspect of this application provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements the above-described method for testing local electrochemical impedance spectroscopy of fuel cells.

[0017] A sixth aspect of this application provides a computer program product, including a computer program that, when executed, is used to implement the above-described method for testing local electrochemical impedance spectroscopy of fuel cells.

[0018] This application's embodiments effectively eliminate the influence of contact voltage drop on local voltage readings in the measurement circuit by introducing a voltage correction mechanism based on PCB parasitic resistance compensation, significantly improving the authenticity and comparability of local impedance data. Furthermore, through a parallel impedance inversion verification method, a quantitative correlation between local measurements and macroscopic responses is established, enhancing the physical reliability of the test results. The overall solution requires no modification to the core architecture of a commercial electrochemical workstation; it can be implemented simply by upgrading the external contact cable and the host computer program, demonstrating good compatibility and engineering application value. This solves the problems in related technologies where traditional electrochemical impedance spectroscopy cannot analyze the local membrane electrode assembly inside the fuel cell, resulting in a lack of analysis of the local distribution characteristics of the fuel cell. Additionally, the timing discrepancy between local signals and overall excitation severely affects the accuracy and repeatability of impedance calculations, limiting the development of fuel cell testing, diagnosis, and performance optimization.

[0019] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0020] The above and additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic diagram of the structure of a fuel cell local electrochemical impedance spectroscopy testing system provided in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a fuel cell local electrochemical impedance spectroscopy testing and data acquisition triggering system according to an embodiment of this application; Figure 3 This is a flowchart of a method for testing the local electrochemical impedance spectroscopy of a fuel cell according to an embodiment of this application; Figure 4 This is a partial Nyquist plot of the effective reaction region 1 of the membrane electrode according to an embodiment of this application; Figure 5 This is a partial Nyquist plot of the effective reaction region 16-18 of the membrane electrode according to an embodiment of this application; Figure 6 This is a local impedance distribution cloud map of the effective reaction region of the membrane electrode according to an embodiment of this application; Figure 7 This is a schematic diagram comparing the overall impedance calculated from local impedance and the direct measurement result of the overall impedance according to an embodiment of this application. Figure 8 This is a schematic diagram of the structure of a fuel cell local electrochemical impedance spectroscopy testing device provided according to an embodiment of this application; Figure 9This is a schematic diagram of the structure of an electronic device provided according to an embodiment of this application.

[0021] Figure label: 10-Fuel cell local electrochemical impedance spectroscopy testing system; 100-Workstation, 200-Sensor array, 300-Data acquisition module; 20-Fuel cell local electrochemical impedance spectroscopy testing device; 400-First acquisition module, 500-Correction module, 600-Generation module; 901-Memory, 902-Processor and 903-Communication interface. Detailed Implementation

[0022] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0023] The following description, with reference to the accompanying drawings, illustrates a fuel cell local electrochemical impedance spectroscopy (FET) testing system and method according to embodiments of this application. Addressing the issues mentioned in the background section regarding the inability of traditional FET testing to analyze the local membrane electrode assembly (MEA) within a fuel cell, resulting in deficiencies in the analysis of local fuel cell distribution characteristics and timing discrepancies between local signals and overall excitation, severely impacting the accuracy and repeatability of impedance calculations and limiting the development of fuel cell testing, diagnostics, and performance optimization, this application provides a fuel cell local electrochemical impedance spectroscopy testing method. This method effectively eliminates the influence of contact voltage drop on local voltage readings by introducing a voltage correction mechanism based on PCB parasitic resistance compensation, significantly improving the authenticity and comparability of local impedance data. Furthermore, a parallel impedance inversion verification method establishes a quantitative correlation between local measurements and macroscopic responses, enhancing the physical reliability of the test results. The overall solution requires no modification to the core architecture of a commercial electrochemical workstation; it can be implemented solely through external contact cables and host computer program upgrades, demonstrating good compatibility and engineering application value. This solves the problems in related technologies, such as the inability of traditional electrochemical impedance spectroscopy to analyze the local membrane electrode inside the fuel cell, resulting in a lack of analysis of the local distribution characteristics of the fuel cell, and the time discrepancy between the local signal and the overall excitation, which seriously affects the accuracy and repeatability of impedance calculation and restricts the development of fuel cell testing, diagnosis and performance optimization.

[0024] Specifically, Figure 1 This is a schematic diagram of a local electrochemical impedance spectroscopy testing system for a fuel cell provided in an embodiment of this application.

[0025] like Figure 1As shown, the fuel cell local electrochemical impedance spectroscopy testing system 10 includes: a workstation 100 for sending digital trigger signals and applying AC excitation signals within a preset frequency range to the test object; a sensor array 200 disposed inside the test object for capturing current response signals and voltage response signals of multiple zones in the membrane electrode area of ​​the test object according to the AC excitation signal; and a data acquisition module 300 for acquiring current response signals and voltage response signals of multiple zones in the membrane electrode area after receiving the digital trigger signal, so as to obtain the electrochemical impedance spectroscopy test results of multiple zones corresponding to the membrane electrode of the test object; wherein, the general-purpose input / output port of the workstation and the external trigger pin of the data acquisition module are connected by a preset two-port cable.

[0026] With the continuous advancement of proton exchange membrane fuel cell technology, its application in new energy vehicles, distributed power generation, and other fields is becoming increasingly widespread. The electrochemical reaction process inside the fuel cell is highly dependent on the coordinated distribution of multiple physical fields such as water, heat, and electricity in the membrane electrode assembly. However, in actual operation, due to factors such as the flow channel structure, the heterogeneity of the gas diffusion layer, and fluctuations in operating conditions, there are significant local non-uniformities in the effective reaction area of ​​the membrane electrode, specifically manifested as spatial differences in local current density, temperature, and water content.

[0027] Electrochemical impedance spectroscopy (EIS), as a non-destructive online diagnostic method, can effectively resolve key performance parameters of fuel cells, such as overall ohmic impedance, charge transfer impedance, and mass transfer impedance, providing important basis for system condition assessment and lifetime prediction. Local electrochemical impedance spectroscopy aims to reveal the electrochemical response characteristics at different spatial locations of the membrane electrode assembly (MEA), thereby enabling accurate identification of key failure modes such as local wetting conditions, catalyst activity degradation, and membrane dryness / flooding.

[0028] However, although EIS testing methods in related technologies can measure the distribution of local current density or temperature through embedded sensor arrays, these methods lack the ability to acquire high-frequency dynamic voltage / current synchronously with AC excitation signals. This can easily lead to timing discrepancies between local signals and overall excitation, making it difficult to support frequency domain analysis of local complex impedances and severely affecting the accuracy of impedance calculations.

[0029] In some embodiments, in order to achieve real-time data acquisition during the local electrochemical impedance spectroscopy test of a fuel cell, this application designs a local electrochemical impedance spectroscopy test system for a fuel cell. This system can automatically trigger data acquisition during the test process. Through the high-frequency dynamic voltage / current acquisition capability synchronized with the AC excitation signal, it eliminates the timing deviation between the local electrical signal and the overall excitation, thereby providing effective support for the frequency domain analysis of the local complex impedance and improving the accuracy of the impedance calculation results.

[0030] For example, the fuel cell local electrochemical impedance spectroscopy testing system in this application includes, but is not limited to, a workstation 100, a sensor array 200 disposed inside the test object, and a data acquisition module 300. The workstation 100 and the data acquisition module 300 are connected via a pre-set two-port cable.

[0031] Here, the preset dual-port cable refers to a pre-defined customized synchronous trigger cable. One end of this customized synchronous trigger cable is connected to the general-purpose input / output port of the workstation 100 through a first interface, and the other end is connected to the external trigger pin of the data acquisition module 300 through a second interface, thereby forming a customized synchronous trigger link.

[0032] Based on the customized synchronous triggering link formed by the customized synchronous triggering cable, when the workstation 100 executes the overall electrochemical impedance spectroscopy (EIS) test script, it can send a digital trigger signal to the customized synchronous triggering cable through its general input / output port; when the data acquisition module 300 detects the digital trigger signal transmitted by the second interface, it can synchronously start the parallel acquisition task of local EIS data.

[0033] In the overall EIS test script executed by workstation 100, there is embedded logic code at the preset code position before the current disturbance sequence begins, which controls the output of trigger signals from the general input / output ports (the trigger signal output instruction is used to control the output of digital trigger signals).

[0034] In this context, the preset code location refers to the pre-determined embedding position of the logic code in the test script that controls the output trigger signal of the general-purpose input / output port. The specific preset code location can be determined by those skilled in the art based on actual circumstances within the test script; this embodiment is merely illustrative and does not impose any specific limitations.

[0035] For example, the first interface in this application may be, but is not limited to, an HD-15 standard interface, and the general-purpose input / output port of workstation 100 may be, but is not limited to, a User I / O port located on the rear panel of the electrochemical workstation. The customized synchronous trigger cable may lead out Pin 7 (Digital Out 0) as a signal output terminal and Pin 6 (Ground) as a digital reference ground terminal from the first interface terminal.

[0036] Furthermore, the second interface in this application may, but is not limited to, be a DSUB-37 standard interface. The external trigger pins of the second interface and the data acquisition module 300 include, but are not limited to, PIN10 (PFI0) and PIN28 (COM) of the data acquisition card in the data acquisition module 300. The customized synchronous trigger cable can use this second interface to connect the digital trigger signal to PIN10 as an external pulse trigger source and PIN28 as a logic reference ground.

[0037] Workstation 100 can be understood here as an electrochemical workstation, which is mainly used to apply AC excitation signals within a preset frequency range to the test item (hereinafter referred to as the fuel cell sample under test), and to send digital trigger signals to the customized synchronous trigger cable through its own general input and output ports.

[0038] In this context, the test object can be understood as a fuel cell sample whose internal local electrochemical impedance spectroscopy is being tested. The AC excitation signal here refers to the sinusoidal signal in the electrochemical impedance spectroscopy test.

[0039] The preset frequency range here can be understood as a pre-set signal frequency range, such as 1~1000 Hz. The specific preset frequency range can be set or adjusted by those skilled in the art according to the actual test situation and actual test requirements. This application embodiment is only for illustrative purposes and does not impose any specific limitations.

[0040] Furthermore, in this embodiment of the application, a fuel cell test bench is designed in the local electrochemical impedance spectroscopy test system for fuel cells. It is mainly used to maintain the operating conditions of the fuel cell sample under test, supply the fuel cell sample under test with reaction gas and coolant at set flow rate and temperature and humidity, and provide electronic load.

[0041] Simultaneously, the electrochemical workstation can apply an AC excitation signal to the test sample, either directly to the battery terminals (voltage mode) or injected via an electronic load (current mode), superimposed on the constant DC load applied by the test bench. This AC excitation signal has minimal disturbance to the overall operating state (DC current and voltage) of the fuel cell, enabling the test fuel cell sample to be tested while generating electricity normally, obtaining the electrical response signals (current response signal and voltage response signal) of the test sample to this AC excitation signal.

[0042] In order to measure the response signal of the fuel cell sample under test to an AC excitation signal (such as a voltage response signal or a current response signal), this embodiment integrates a sensor array 200 based on a printed circuit board (PCB) inside the fuel cell sample under test, which is used to capture local electrical signals at different spatial locations (different partitions) of the membrane electrode region of the fuel cell sample under test—current response signal (current distribution signal) and voltage response signal (voltage fluctuation signal).

[0043] The data acquisition module 300 is a multi-channel high-speed data acquisition module. It can be connected to the printed circuit board of the sensor array in the fuel cell sample under test via a data acquisition cable harness. When the digital trigger signal transmitted through the second interface is detected via a customized synchronization cable, it acquires the current response signal and voltage response signal of each zone within the membrane electrode area of ​​the fuel cell sample under test. Both the current response signal and the voltage response signal are dynamic response signals.

[0044] After acquiring the current response signal and voltage response signal of each zone in the membrane electrode area of ​​the fuel cell sample under test, the control and signal processing host computer program built into the data acquisition module 300 can process the current response signal and voltage response signal to obtain the electrochemical impedance spectroscopy test results of multiple zones corresponding to the membrane electrode of the test item.

[0045] The control and signal processing host computer program can communicate with workstation 100 and data acquisition module 300 via the data bus to configure sampling parameters and perform time-domain to frequency-domain transformation on the acquired overall and local signals to reconstruct the local complex impedance at different locations of the membrane electrode. The sampling parameters include, but are not limited to, the sampling frequency during data acquisition, the gain factor, and the frequency scanning range for specific impedance measurements.

[0046] For example, Figure 2 This is a schematic diagram of the structure of a fuel cell local electrochemical impedance spectroscopy testing and data acquisition triggering system according to an embodiment of this application. Figure 2 As shown, the fuel cell local electrochemical impedance spectroscopy test and data acquisition triggering system includes, but is not limited to, a control and signal processing host computer program 101, an electrochemical workstation 102, a general purpose input / output (GPIO) port 102a, a multi-channel data acquisition module 103, an external trigger pin 103a, a fuel cell test bench 104, a fuel cell sample under test 105, and a customized synchronous trigger cable 106.

[0047] The specific workflow can be, but is not limited to, represented as follows: In this embodiment, the digital trigger signal output terminal of the electrochemical workstation and the digital trigger signal input terminal of the multi-channel data acquisition module can be connected through a customized synchronous trigger cable to construct a synchronous trigger link. This enables the transmission of the digital trigger signal output from a specified pin in the general input / output interface of the electrochemical workstation to a specified trigger input pin of the data acquisition card of the multi-channel data acquisition module. When the data acquisition card of the multi-channel data acquisition module detects a valid trigger signal through its trigger input pin, it automatically starts the local EIS data acquisition process, thereby achieving synchronization with the start time of the overall EIS test initiated by the electrochemical workstation.

[0048] Furthermore, in the EIS test script of the electrochemical workstation, a digital trigger signal output instruction (such as making a specified digital output pin output a continuous high-level signal or making a specified digital output pin output a pulse high-level signal, etc.) is embedded at the beginning of the overall EIS test. Then, the data acquisition start condition of the multi-channel data acquisition module is configured to be controlled by the digital trigger signal received by the digital trigger signal input terminal.

[0049] Then, start the EIS test script on the electrochemical workstation to perform a comprehensive EIS test: Before the current disturbance sequence is started, the electrochemical workstation embeds a digital trigger signal output command. When the overall electrochemical impedance spectroscopy test script executes the digital trigger signal output command, the electrochemical workstation can control the designated digital output pin of its general-purpose input / output interface to output a rising edge level transition signal according to the digital trigger signal output command, based on the start time of the current disturbance of the overall EIS test or a certain starting reference time. This causes its own general-purpose input / output port to generate a rising edge level transition signal, thereby forming a digital trigger signal.

[0050] The digital trigger signal is transmitted to the multi-channel data acquisition module via a customized synchronous trigger cable, triggering the edge detection trigger mechanism in the host computer program of the multi-channel data acquisition module, instantly starting the parallel data recording task of all acquisition channels, and realizing hardware synchronization of the overall EIS excitation and local signal acquisition on a millisecond time scale.

[0051] The edge detection mechanism of the host computer program of the multi-channel data acquisition module can be set to rising edge trigger mode, but is not limited to. That is, when the external trigger pin receives the rising edge level jump signal output by the electrochemical workstation (that is, the received voltage signal generates a level step), the synchronous sampling function of all analog input channels is activated, and the sampling clock is driven by the high stability crystal oscillator inside the device.

[0052] Next, the impedance reconstruction algorithm built into the control and signal processing host computer program in the multi-channel data acquisition module can use the digital trigger signal issued by the electrochemical workstation as a time reference to perform cross-correlation operation on the local dynamic current sequence (current response signal) acquired by the multi-channel data acquisition module and the disturbance voltage signal (voltage response signal) of the fuel cell under test. It can extract the steady-state response components of each spatial position of the membrane electrode at a specific frequency and calculate the corresponding complex impedance value, that is, the electrochemical impedance spectrum test results of multiple partitions corresponding to the membrane electrode.

[0053] The fuel cell local electrochemical impedance spectroscopy (EIS) testing system proposed in this application integrates an electrochemical workstation, a multi-channel data acquisition module, and a customized hardware triggering link into a collaborative testing system. It achieves, for the first time, precise synchronous acquisition of the overall EIS and local EIS of a fuel cell on a millisecond-level timescale, fundamentally solving the impedance calculation distortion problem caused by timing mismatch. The edge-triggered hardware synchronization strategy adopted does not rely on software polling or network latency, exhibiting high robustness and repeatability, and is suitable for long-term stable operation in complex electromagnetic environments. Combined with a spatially distributed sensor array and a partitioned impedance reconstruction algorithm, it can intuitively present the spatial heterogeneity of current density, wetting state, and catalytic activity within the membrane electrode assembly (MEA), providing microscopic evidence for fault location and lifetime prediction. This solves the problem that traditional electrochemical impedance spectroscopy testing cannot analyze the local areas of the MEA within a fuel cell, resulting in insufficient analysis of the local distribution characteristics of the fuel cell, and that the timing deviation between local signals and overall excitation severely affects the accuracy and repeatability of impedance calculations, limiting the development of fuel cell testing, diagnosis, and performance optimization.

[0054] Next, referring to the accompanying drawings, a method for testing the local electrochemical impedance spectroscopy of a fuel cell according to an embodiment of this application is described.

[0055] Specifically, Figure 3 This is a flowchart illustrating a method for testing the local electrochemical impedance spectroscopy of a fuel cell according to an embodiment of this application. Figure 3 As shown, the fuel cell local electrochemical impedance spectroscopy testing method uses the fuel cell local electrochemical impedance spectroscopy testing system described in the previous embodiment, wherein the method includes the following steps: In step S301, the total input current of the test object under preset test conditions, as well as the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the test object are obtained.

[0056] It is understandable that the preset test conditions here can be understood as the test conditions set in advance when performing local electrochemical impedance spectroscopy on the test object. For example, the perturbation frequency range of the AC excitation signal applied to the test object by the electrochemical workstation, the test environment conditions, etc.

[0057] In some embodiments, this application can obtain the total input current of the test item under certain test conditions, as well as the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the test item under certain test conditions.

[0058] Here, the target membrane electrode region can be understood as the membrane electrode region in the test item that produces an effective reaction under certain test conditions.

[0059] Furthermore, for ease of calculation, when obtaining voltage time-domain data and current time-domain data of different partitions of the effective membrane electrode region, this application may, but is not limited to, divide the effective membrane electrode region according to certain rules, and obtain different partitions (e.g., 5×5 or 10×10 regions).

[0060] Each partition represents a spatial location within the effective membrane electrode region. The spatial location refers to the specific coordinates of these partitions within the effective membrane electrode region (e.g., the partition in the 2nd row and 3rd column).

[0061] For example, the effective membrane electrode area of ​​a certain tested fuel cell sample is 25 cm². 2 This application may, but is not limited to, be based on a fixed number (e.g., a total of 25 areas) or a fixed partition area (e.g., 1 cm²). 2 The fixed division rules divide the effective membrane electrode area into 25 regions.

[0062] Voltage time-domain data and current time-domain data can be understood here as the sequence of instantaneous voltage and current values ​​of the test object measured at fixed time intervals (sampling periods) under certain test conditions.

[0063] Optionally, in one embodiment of this application, obtaining the total input current of the item under test under preset test conditions, and the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the item under test, includes: applying a target DC load to the item under test and superimposing an AC excitation signal within a preset frequency range onto the target DC load; and determining the total input current of the item under test and the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the item under test under preset test conditions when the target DC load and the AC excitation signal within a preset frequency range are superimposed on the item under test.

[0064] In practical applications, when obtaining the total input current of the test item under certain test conditions, this application may, but is not limited to, apply a target DC load to the test item and superimpose a target AC current on the target DC load, and then obtain the total input current of the test item after the superimposed target AC current and target DC load are applied.

[0065] Here, the target DC load refers to a constant DC load, which can continuously consume a stable DC current, thus ensuring that the device under test always outputs a fixed current value. The specific target DC load can be set or adjusted by those skilled in the art based on actual test conditions and requirements. The embodiments in this application are for illustrative purposes only and do not impose specific limitations.

[0066] For example, this application can use a setting of the operating current density of the fuel cell sample under test to be 0.5 A / cm². 2 The constant DC load applied to the sample by the fuel cell test platform in the fuel cell local electrochemical impedance spectroscopy test system. It is the product of the operating current density and the active area of ​​the fuel cell under test.

[0067] The current disturbance mode is adopted synchronously, that is, the workstation 100 applies a sinusoidal AC current signal (AC excitation signal) with an effective value of 3A and a frequency of 1~1000 Hz to the two electrodes of the test object through the electronic load, so as to complete the superposition of the AC turbulence signal on the constant DC load.

[0068] Additionally, in this embodiment of the application, the stoichiometric ratios of the anode and cathode gas inlets of the test item can be set to 1.2 and 2.0, respectively, the humidity of the anode and cathode gas inlets is 100%, the back pressure of the anode and cathode gas is 50 kPa, and the operating temperature of the anode and cathode is 70°C.

[0069] At this time, the preset test conditions in this application embodiment include, but are not limited to, a target DC load, an AC excitation signal with a preset frequency range (the effective value of the signal can be set or adjusted by those skilled in the art according to the actual test situation and needs; this application embodiment is only an exemplary illustration and does not impose specific limitations), as well as the intake stoichiometry ratio of the anode and cathode, the gas back pressure, and the operating temperature.

[0070] After applying a constant DC load to the sample under test, the host computer monitoring program can be started in this embodiment of the application so that while the workstation 100 applies an AC excitation signal to generate a digital trigger signal, the data acquisition module 300 can simultaneously receive the digital trigger signal and acquire the total input current of the test item under various frequency disturbances during the test, as well as the voltage time domain data and current time domain data at multiple spatial locations in the effective reaction membrane electrode area of ​​the test item, at a certain signal acquisition frequency (such as 10000Hz).

[0071] The expression for the total input current can be, but is not limited to, the following:

[0072] in, for Total input current at time t, For a constant DC load, The amplitude of the alternating current signal. For the frequency of the AC excitation signal, This is the initial phase.

[0073] Step S302: Correct the voltage time-domain data according to the preset equivalent contact resistance value to obtain the corrected voltage time-domain data. Convert the corrected voltage time-domain data and current time-domain data to the frequency domain to extract the current of multiple partitions and their corresponding amplitude and phase, as well as the voltage of multiple partitions and their corresponding amplitude and phase.

[0074] As one possible approach, after obtaining voltage time-domain data and current time-domain data at multiple spatial locations within the effective reaction membrane electrode area of ​​the test item, the embodiments of this application can also correct the collected voltage time-domain data according to a preset equivalent contact resistance value to eliminate DC bias and environmental noise, thereby obtaining corrected voltage time-domain data that eliminates the influence of contact voltage drop.

[0075] Here, the preset equivalent contact resistance value can be understood as the equivalent resistance value of the inherent parasitic resistance in the current signal measurement circuit of the test object in each partition.

[0076] After correcting the voltage time-domain data, the embodiments of this application can use the discrete Fourier transform algorithm to convert the corrected voltage time-domain data and current time-domain data to the frequency domain, thereby obtaining voltage frequency-domain data and current frequency-domain data. Based on the voltage frequency-domain data and current frequency-domain data, the current, voltage, and their respective amplitudes and phases at multiple spatial locations in the effective reaction membrane electrode region of the test object can be extracted for subsequent calculations.

[0077] Optionally, in one embodiment of this application, before correcting the voltage time-domain data according to the preset equivalent contact resistance value, the method includes: applying a target current to the current signal measurement circuit of the test object, obtaining the voltage drop of the target current across the circuit parasitic resistance of the current signal measurement circuit; obtaining the overall equivalent contact resistance value of the current signal measurement circuit based on the voltage drop, so as to determine the preset equivalent contact resistance value based on the overall local equivalent contact resistance value.

[0078] In some embodiments, this application may, but is not limited to, apply a preset current to the current signal measurement circuit of the test item and obtain the overall fixed resistance value (i.e., the overall equivalent contact resistance value) of the current signal measurement circuit based on the voltage drop (voltage drop) generated on the parasitic resistance of the circuit by the preset current.

[0079] Because the circuits are connected in parallel, the embodiments of this application can determine the preset equivalent contact resistance value by combining the parallel calculation rules of resistors and the total number of partitions. This preset equivalent contact resistance value can be automatically written into the storage area of ​​the control and signal processing host computer program.

[0080] In this context, the preset current refers to a predetermined, fixed, and known current. The specific preset current (including its magnitude) can be set or adjusted by those skilled in the art based on actual testing conditions and requirements. This embodiment is merely illustrative and does not impose any specific limitations.

[0081] In simple terms, before each formal overall EIS test, the embodiments of this application can apply a known current to the current signal measurement circuit of the test object and measure the voltage drop generated on the parasitic resistance of the current signal measurement circuit. The overall fixed resistance value of the current signal measurement circuit can be calculated by Ohm's law. The resistance value obtained by multiplying the fixed resistance value by the total number of partitions is the preset equivalent contact resistance value.

[0082] It should be noted that the overall fixed resistance value of the current signal measurement circuit is measurable, which is the "fixed resistance value corresponding to the voltage drop generated on the parasitic resistance of the current signal measurement circuit after a known current is applied to the current signal measurement circuit" in the embodiments of this application. The preset equivalent contact resistance value is calculated by multiplying this overall fixed resistance value by the total number of regions divided in the membrane electrode plane, and the resistance value used for voltage correction in a single region is obtained, which is the preset equivalent contact resistance value. The two are not the same.

[0083] In this embodiment, the signal measurement circuit includes traces, contacts, and connectors on a printed circuit board (PCB). Therefore, the preset equivalent contact resistance value (Rcontact) specifically refers to the equivalent value of the parasitic resistance introduced by the relevant part of the printed circuit board (PCB). This equivalent contact resistance value (Rcontact) can effectively characterize the combined effect of the inherent parasitic resistance in the current signal measurement circuit.

[0084] For example, in local electrochemical impedance spectroscopy testing, the voltage measurement value corresponding to the local voltage signal acquired by the sensor array and the matching printed circuit board arranged on the surface of the electrode under test can be called the original voltage measurement value, and the current measurement value corresponding to the local current signal acquired by the sensor array and the matching printed circuit board arranged on the surface of the electrode under test can be called the original current measurement value.

[0085] After receiving the original voltage and current measurements, the control and signal processing host computer program combines them with the stored preset equivalent contact resistance value to correct the voltage time-domain data, thereby obtaining the corrected voltage time-domain data. This allows for online point-by-point voltage compensation and the output of the corrected voltage sequence.

[0086] In this embodiment of the application, the equivalent contact resistance value is based on a preset equivalent contact resistance value ( The expression for correcting voltage time-domain data can be, but is not limited to, expressed as follows:

[0087] in, The corrected voltage time-domain data, To obtain the raw voltage measurements synchronously under the same electrochemical test excitation, The raw current measurements were acquired synchronously under the same electrochemical test excitation.

[0088] Taking position 1 in the effective reaction region of the membrane electrode assembly of the fuel cell sample under test as an example, the data obtained by the multi-channel data acquisition module... It is 0.51 A. It is 0.826V.

[0089] The overall fixed resistance of the tested fuel cell sample is 0.5 milliohms. Based on Ohm's law, the resistance of a single region is 0.5 × 25 = 12.5 milliohms.

[0090] The corrected voltage value for: 0.826 - 0.51 * 12.5 / 1000 = 0.820 It should be noted that the calculation here is for the corrected voltage value corresponding to a single region.

[0091] This application embodiment can determine the equivalent contact resistance value generated by the signal circuit in each partition by applying a certain current to the current signal measurement circuit of the battery under test. Then, the voltage value of each partition can be corrected by the equivalent contact resistance value, which can effectively eliminate the influence of voltage drop on the voltage time domain data of each partition. This provides an accurate data basis for the subsequent electrochemical impedance spectroscopy test results of each partition, thereby effectively improving the accuracy of the electrochemical impedance spectroscopy test results of each partition.

[0092] Step S303: Based on the current and its corresponding amplitude and phase of multiple partitions and the voltage and its corresponding amplitude and phase of multiple partitions, generate the electrochemical impedance spectroscopy test results of multiple partitions.

[0093] In some embodiments, based on the current and its corresponding amplitude and phase at multiple spatial locations of the effective reactive membrane electrode region of the test article, and the voltage and its corresponding amplitude and phase at multiple locations, this application can generate electrochemical impedance spectroscopy test results for multiple partitions corresponding to the effective reactive membrane electrode region of the test article.

[0094] For example, after obtaining the corrected voltage time-domain data and current time-domain data, embodiments of this application can use the Discrete Fourier Transform algorithm to convert to the frequency domain, and extract the current and voltage at each location in the frequency domain. The amplitude and phase information below can be expressed, but is not limited to, as follows: ; ; in, Indicates the membrane electrode number The current signal at each location has a frequency The frequency domain complex result at that point, Indicates the first The location is in The corrected time-domain sampled value of the current at time t. The sampling period is Denotes the complex exponential basis functions. Indicates the membrane electrode number The voltage signal at each location at a frequency The frequency domain complex result at that point, Indicates the first The location is in The corrected time-domain sampled value of the voltage at time 1; Based on the frequency domain response data at each location, the frequency of multiple zones corresponding to the effective reactive membrane electrode region at a preset frequency can be calculated. Electrochemical impedance spectroscopy test results (local complex impedance): ; in, Indicates the membrane electrode number The position at frequency The frequency domain complex impedance results at that point, Indicates the impedance magnitude. This represents the phase difference between the voltage signal and the current signal.

[0095] By repeating the above steps at different spatial locations within the effective reaction area of ​​the membrane electrode, the response of each region at a single frequency can be obtained. By summing the results from all partitions, the impedance value (including amplitude and phase) at a given frequency can be obtained. The impedance spatial distribution (the spatial distribution of impedance inside the battery, which shows the change of impedance value with the location of the partition at a certain fixed frequency).

[0096] By traversing the entire frequency scan range and summarizing the local impedance data at each frequency point, a complete partitioned electrochemical impedance spectroscopy can be constructed. That is, repeat the above process for each preset frequency within the preset frequency range (from high frequency to low frequency, for example, from 1000Hz to 1Hz), and summarize the calculation results of all frequency points to obtain the complete partitioned electrochemical impedance spectrum (EIS spectrum measured independently for each partition).

[0097] Optionally, in one embodiment of this application, after generating the electrochemical impedance spectroscopy test results for multiple partitions, the method further includes: calculating the electrochemical impedance spectra of multiple partitions in parallel to generate a Nyquist plot of the overall impedance corresponding to the membrane electrode; comparing the Nyquist plot of the overall impedance with a preset Nyquist plot of the overall impedance, and generating a verification result of the electrochemical impedance spectroscopy test results for multiple partitions based on the comparison result.

[0098] In some embodiments, in order to evaluate the accuracy and reliability of the local reconstructed data (EIS spectra measured independently for each partition), this application may also calculate the electrochemical impedance spectra of multiple partitions in parallel after generating the electrochemical impedance spectra of each partition corresponding to the membrane electrode of the test article, and generate the overall impedance corresponding to the membrane electrode to draw the Nyquist plot.

[0099] Then, the embodiments of this application can compare the Nyquist plot drawn by the overall impedance with the Nyquist plot drawn by the preset overall impedance to verify that the multiple partition electrochemical impedance spectra calculated in the embodiments of this application are reliable based on the comparison results between the two.

[0100] In this context, the preset overall impedance plotting of the Nyquist plot can be understood as the raw data of the overall electrochemical impedance spectrum of the fuel cell sample being tested, which is simultaneously acquired by workstation 100 when an AC excitation signal within a preset frequency range is applied to the fuel cell sample under test.

[0101] That is, based on the electrical principle that the impedance of each region of the membrane electrode is in parallel with the overall impedance of the battery, the theoretical overall impedance of each region can be calculated according to the parallel circuit formula, and the result can be compared with the overall impedance measured by the electrochemical workstation, thereby effectively evaluating the accuracy and reliability of the local reconstruction data.

[0102] For example, this application can determine the preset frequency based on the parallel relationship between the overall impedance of the fuel cell and the impedance of each region of the membrane electrode. Sub-districts impedance The impedance after parallel connection is obtained through parallel calculation. The Nyquist plot was compared with the overall impedance measured by the electrochemical workstation, where the imaginary part sign was reversed.

[0103] Each zone impedance The parallel calculation formula can be, but is not limited to, expressed as: .

[0104] in, for (In this embodiment, it is set to one of the frequencies from 1000Hz to 1Hz.)

[0105] In this embodiment of the application, it was calculated that the real impedance at position 1 in the effective reaction region of the membrane electrode of the tested fuel cell sample at 1000 Hz is 0.0646 ohms, and the complex impedance is 0.0105 ohms; Figure 4 As shown, Figure 4 This is a partial Nyquist plot of the effective reaction region 1 of the membrane electrode according to an embodiment of this application; Similarly, the real impedance at position 16 of the effective reaction region of the membrane electrode can be calculated to be 0.0758 ohms and the complex impedance to be -0.0134 ohms; the real impedance at position 17 is 0.0870 ohms and the complex impedance to be -0.0142 ohms; and the real impedance at position 18 is 0.101 ohms and the complex impedance to be -0.0212 ohms. The local Nyquist plots of the effective reaction regions of the membrane electrode at positions 16-18 are shown below. Figure 5 As shown, Figure 5 This is a partial Nyquist plot of the effective reaction region 16-18 of the membrane electrode according to an embodiment of this application; Figure 6 This is a local impedance distribution cloud map showing the effective reaction region of the membrane electrode according to an embodiment of this application. For example... Figure 6 As shown in the figure, 1-25 represents the corresponding effective reaction region 1-25 of the membrane electrode. Figure 7 This is a schematic diagram comparing the overall impedance calculated from local impedance and the direct measurement result of the overall impedance according to an embodiment of this application. Figure 7 As shown, it illustrates the overall impedance obtained by local impedance calculation (overall impedance Nyquist plot) and the direct measurement result of overall impedance (preset overall impedance Nyquist plot) in the embodiments of this application.

[0106] Depend on Figure 7 It can be seen that when the real impedance is 4 milliohms, the overall complex impedance calculated by the local impedance obtained by the fuel cell local electrochemical impedance spectroscopy test method in this application embodiment is 0.86 milliohms, and the directly measured overall complex impedance is 0.85 milliohms, with a relative deviation of only 1.2%.

[0107] When the real impedance is 6 milliohms, the total complex impedance calculated by the local impedance obtained by the fuel cell local electrochemical impedance spectroscopy test method in the embodiment of this application is 1.63 milliohms, and the direct measurement result of the total complex impedance is 1.60 milliohms, with a relative deviation of only 1.9%.

[0108] Therefore, it can be effectively verified that the local impedance obtained by the fuel cell local electrochemical impedance spectroscopy test method in the embodiments of this application has extremely high reliability and accuracy.

[0109] The embodiments of this application can achieve high-precision synchronous acquisition of overall and local electrochemical impedance spectroscopy (EIS), and possess high spatiotemporal resolution, strong synchronization, and high-precision signal processing capabilities. This effectively overcomes the bottlenecks in characterizing the local performance of fuel cells, enabling precise analysis of the local electrochemical behavior of the fuel cell membrane electrode assembly (MEA) and clarifying the multi-physics distribution of the MEA components within the fuel cell. This effectively solves the problems of related EIS testing methods, which are mainly geared towards single cells or the entire stack, only acquiring macroscopically averaged impedance information and failing to reflect the performance heterogeneity at the microscale within the MEA. These methods lack precise characterization capabilities for local spatial heterogeneity, and the voltage measurement error introduced by parasitic resistance in the sensor circuit is not effectively corrected, thus limiting the reliability of local EIS data.

[0110] The fuel cell local electrochemical impedance spectroscopy testing method proposed in this application effectively eliminates the influence of contact voltage drop on local voltage readings by introducing a voltage correction mechanism based on PCB parasitic resistance compensation, significantly improving the authenticity and comparability of local impedance data. Furthermore, a parallel impedance inversion verification method establishes a quantitative correlation between local measurements and macroscopic responses, enhancing the physical reliability of the test results. The overall solution requires no modification to the core architecture of a commercial electrochemical workstation; it can be implemented simply by upgrading the external contact cable and the host computer program, demonstrating good compatibility and engineering application value. This solves the problems in related technologies where traditional electrochemical impedance spectroscopy cannot analyze the local membrane electrode assembly inside the fuel cell, resulting in a lack of analysis of the local distribution characteristics of the fuel cell. Additionally, the timing discrepancy between local signals and overall excitation severely affects the accuracy and repeatability of impedance calculations, limiting the development of fuel cell testing, diagnosis, and performance optimization.

[0111] Next, referring to the accompanying drawings, a fuel cell local electrochemical impedance spectroscopy testing device according to an embodiment of this application is described.

[0112] Figure 8 This is a schematic diagram of the structure of the fuel cell local electrochemical impedance spectroscopy testing device according to an embodiment of this application.

[0113] like Figure 8As shown, the fuel cell local electrochemical impedance spectroscopy testing device 20 includes: a first acquisition module 400, a correction module 500, and a generation module 600.

[0114] The first acquisition module 400 is used to acquire the total input current of the test object under preset test conditions, as well as the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the test object.

[0115] The correction module 500 is used to correct the voltage time-domain data according to the preset equivalent contact resistance value, obtain the corrected voltage time-domain data, and convert the corrected voltage time-domain data and current time-domain data to the frequency domain to extract the current of multiple partitions and their corresponding amplitude and phase, as well as the voltage of multiple partitions and their corresponding amplitude and phase.

[0116] The generation module 600 is used to generate electrochemical impedance spectroscopy test results for multiple partitions based on the current and its corresponding amplitude and phase of multiple partitions and the voltage and its corresponding amplitude and phase of multiple partitions.

[0117] Optionally, in one embodiment of this application, the first acquisition module 400 includes a testing unit and a determining unit.

[0118] The test unit is used to apply a target DC load to the object under test and to superimpose an AC excitation signal within a preset frequency range onto the target DC load.

[0119] The determination unit is used to determine the total input current of the test object under preset test conditions and the voltage time-domain data and current time-domain data of multiple zones in the target membrane electrode area of ​​the test object when a target DC load and AC excitation signal are superimposed on the test object.

[0120] Optionally, in one embodiment of this application, it further includes: a second acquisition module and a determination module.

[0121] The second acquisition module is used to apply a target current to the current signal measurement circuit of the test object before correcting the voltage time domain data according to the preset equivalent contact resistance value, and to acquire the voltage drop of the target current across the circuit parasitic resistance of the current signal measurement circuit.

[0122] The determination module is used to obtain the overall equivalent contact resistance value of the current signal measurement circuit based on the voltage drop, and to determine the preset equivalent contact resistance value based on the overall equivalent contact resistance value.

[0123] Optionally, in one embodiment of this application, it further includes a calculation module and a comparison module.

[0124] The calculation module is used to calculate the electrochemical impedance spectra of multiple partitions in parallel after generating the electrochemical impedance spectroscopy test results of multiple partitions, and to generate the overall impedance of the membrane electrode and draw the Nyquist plot.

[0125] The comparison module is used to compare the Nyquist plot of the overall impedance with the preset overall impedance Nyquist plot, and to generate verification results of the electrochemical impedance spectroscopy test results of multiple partitions based on the comparison results.

[0126] It should be noted that the foregoing explanation of the embodiment of the fuel cell local electrochemical impedance spectroscopy test method also applies to the fuel cell local electrochemical impedance spectroscopy test device of this embodiment, and will not be repeated here.

[0127] The fuel cell local electrochemical impedance spectroscopy testing device proposed in this application effectively eliminates the influence of contact voltage drop on local voltage readings by introducing a voltage correction mechanism based on PCB parasitic resistance compensation, significantly improving the authenticity and comparability of local impedance data. Furthermore, a quantitative correlation between local measurement and macroscopic response is established through a parallel impedance inversion verification method, enhancing the physical reliability of the test results. The overall solution requires no modification to the core architecture of a commercial electrochemical workstation; it can be implemented simply by upgrading the external contact cable and the host computer program, demonstrating good compatibility and engineering application value. This solves the problems in related technologies where traditional electrochemical impedance spectroscopy cannot analyze the local membrane electrode assembly inside the fuel cell, resulting in a lack of analysis of the local distribution characteristics of the fuel cell. Additionally, the timing discrepancy between local signals and overall excitation severely affects the accuracy and repeatability of impedance calculations, limiting the development of fuel cell testing, diagnosis, and performance optimization.

[0128] Figure 9 A schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: The memory 901, the processor 902, and the computer program stored on the memory 901 and capable of running on the processor 902.

[0129] When the processor 902 executes the program, it implements the fuel cell local electrochemical impedance spectroscopy test method provided in the above embodiments.

[0130] Furthermore, electronic devices also include: Communication interface 903 is used for communication between memory 901 and processor 902.

[0131] The memory 901 is used to store computer programs that can run on the processor 902.

[0132] The memory 901 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0133] If the memory 901, processor 902, and communication interface 903 are implemented independently, then the communication interface 903, memory 901, and processor 902 can be interconnected via a bus to complete communication between them. The bus can be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, or an Extended Industry Standard Architecture (EISA) bus, etc. Buses can be categorized as address buses, data buses, control buses, etc. For ease of representation, Figure 9 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0134] Optionally, in a specific implementation, if the memory 901, processor 902, and communication interface 903 are integrated on a single chip, then the memory 901, processor 902, and communication interface 903 can communicate with each other through an internal interface.

[0135] The processor 902 may be a central processing unit (CPU), an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of this application.

[0136] This application also provides a computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements the above-described method for testing local electrochemical impedance spectroscopy of fuel cells.

[0137] This application also provides a computer program product, including a computer program that can run computer instructions. When the computer instructions are executed by a processor, they implement the fuel cell local electrochemical impedance spectroscopy testing method provided in this application.

[0138] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0139] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "N" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0140] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or N executable instructions for implementing custom logic functions or processes, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the functions involved, as should be understood by those skilled in the art to which embodiments of this application pertain.

[0141] The logic and steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0142] It should be understood that the various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, the N steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, it can be implemented using any one or more of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0143] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0144] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0145] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A local electrochemical impedance spectroscopy testing system for fuel cells, characterized in that, include: The workstation is used to send digital trigger signals and apply AC excitation signals within a preset frequency range to the test object; A sensor array disposed inside the test object is used to capture current response signals and voltage response signals of multiple zones in the membrane electrode region of the test object according to the AC excitation signal. When the data acquisition module receives the digital trigger signal, it acquires the current response signal and voltage response signal of multiple partitions in the membrane electrode area to obtain the electrochemical impedance spectroscopy test results of multiple partitions corresponding to the membrane electrode of the test item. The general-purpose input / output port of the workstation and the external trigger pin of the data acquisition module are connected by a preset dual-port cable. The output instruction of the digital trigger signal is embedded at the start position of the overall electrochemical impedance spectroscopy test in the test script of the workstation, and the data acquisition start condition of the data acquisition module is configured to be the digital trigger signal received by the digital trigger signal input terminal. When the workstation applies an AC excitation signal within a preset frequency range to the test object, the workstation synchronously controls a designated digital output pin of the general-purpose input / output interface to output a rising edge level transition signal according to the digital trigger signal output instruction, so that the general-purpose input / output port of the workstation generates a rising edge level transition signal, and the rising edge level transition signal constitutes the digital trigger signal. The digital trigger signal is transmitted to the data acquisition module via the preset dual-port cable, triggering the edge detection trigger mechanism in the data acquisition module to acquire the current response signal and voltage response signal of multiple zones in the membrane electrode area. The edge detection trigger mechanism is a rising edge trigger mode.

2. A method for testing local electrochemical impedance spectroscopy in a fuel cell, characterized in that, The fuel cell local electrochemical impedance spectroscopy testing system as described in claim 1 is used, wherein the method includes the following steps: The total input current of the test object under preset test conditions is obtained, as well as the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the test object. The voltage time-domain data is corrected according to the preset equivalent contact resistance value to obtain the corrected voltage time-domain data. The corrected voltage time-domain data and current time-domain data are converted to the frequency domain to extract the current of multiple partitions and their corresponding amplitude and phase, as well as the voltage of multiple partitions and their corresponding amplitude and phase. Based on the current and its corresponding amplitude and phase of the multiple partitions, and the voltage and its corresponding amplitude and phase of the multiple partitions, the electrochemical impedance spectroscopy test results of the multiple partitions are generated.

3. The method for testing local electrochemical impedance spectroscopy in fuel cells according to claim 2, characterized in that, The acquisition of the total input current of the test object under preset test conditions, and the voltage time-domain data and current time-domain data of multiple zones within the target membrane electrode region of the test object, includes: A target DC load is applied to the object under test, and an AC excitation signal within a preset frequency range is superimposed on the target DC load; When the target DC load and the AC excitation signal are superimposed on the test object, the total input current of the test object under the preset test conditions and the voltage time-domain data and the current time-domain data of multiple partitions in the target membrane electrode area of ​​the test object are determined.

4. The method for testing local electrochemical impedance spectroscopy in fuel cells according to claim 2, characterized in that, Before correcting the voltage time-domain data based on a preset equivalent contact resistance value, the method further includes: A target current is applied to the current signal measurement loop of the test object, and the voltage drop of the target current across the loop parasitic resistance of the current signal measurement loop is obtained; The overall equivalent contact resistance value of the current signal measurement circuit is obtained based on the voltage drop, and the preset equivalent contact resistance value is determined based on the overall equivalent contact resistance value.

5. The method for testing local electrochemical impedance spectroscopy in fuel cells according to claim 2, characterized in that, After generating the electrochemical impedance spectroscopy test results for multiple said partitions, the method further includes: Multiple partitioned electrochemical impedance spectra are calculated in parallel to generate the overall impedance corresponding to the membrane electrode and plot the Nyquist plot. By comparing the Nyquist plot of the overall impedance with the preset overall impedance Nyquist plot, verification results of the electrochemical impedance spectroscopy test results of multiple partitions are generated based on the comparison results.

6. A local electrochemical impedance spectroscopy testing device for fuel cells, characterized in that, include: The acquisition module is used to acquire the total input current of the test object under preset test conditions, as well as the voltage time-domain data and current time-domain data of multiple partitions in the target membrane electrode area of ​​the test object. The correction module is used to correct the voltage time-domain data according to the preset equivalent contact resistance value to obtain the corrected voltage time-domain data, and convert the corrected voltage time-domain data and current time-domain data to the frequency domain to extract the current of multiple partitions and their corresponding amplitude and phase, as well as the voltage of multiple partitions and their corresponding amplitude and phase. The generation module is used to generate electrochemical impedance spectroscopy test results for multiple partitions based on the currents and their corresponding amplitudes and phases of the multiple partitions and the voltages and their corresponding amplitudes and phases of the multiple partitions.

7. The apparatus according to claim 6, characterized in that, The acquisition module includes: The test unit is used to apply a target DC load to the test object and superimpose an AC excitation signal within a preset frequency range onto the target DC load; The determining unit is configured to determine, under preset test conditions, the total input current of the test object and the voltage time-domain data and the current time-domain data of multiple partitions in the target membrane electrode region of the test object, when the target DC load and the AC excitation signal are superimposed on the test object.

8. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, the processor executing the program to implement the fuel cell local electrochemical impedance spectroscopy testing method as described in any one of claims 2-5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, The program is executed by the processor to implement the method for testing local electrochemical impedance spectroscopy of fuel cells as described in any one of claims 2-5.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed, it is used to implement the fuel cell local electrochemical impedance spectroscopy testing method as described in any one of claims 2-5.

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