Electrolytic galvanic pile performance evaluation method and device

Abstract

The invention discloses an electrolytic stack performance evaluation method and equipment. The method comprises the following steps: acquiring an electrochemical impedance spectrum measured under a plurality of current densities in the operation process of the electrolysis galvanic pile; according to the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, determining the characteristic frequency bands of a plurality of polarization processes in the electrolysis galvanic pile, and according to the characteristic frequency bands, determining the solution ion diffusion process, the cathode and anode charge transfer process and the substance transfer process in the electrolysis galvanic pile; and performing performance evaluation. According to the method, different electrochemical processes are quantified by identifying different frequencies by utilizing a relaxation time distribution method, so that the whole process of the electrolysis galvanic pile, such as internal resistance of each part, an ion transmission process, a cathode and anode reaction kinetic process, a bubble / electrolyte transmission process and other internal electrochemical characteristic indexes, is analyzed in detail; therefore, the performance evaluation and fault diagnosis of the electrolysis galvanic pile are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen energy and fuel cells, and in particular to an electrolysis stack performance evaluation method, an electronic device, a storage medium and a computer program product. BACKGROUND

[0002] Electrolytic hydrogen production, especially alkaline water electrolysis, is widely concerned in commercial / industrial applications due to its simple structure and low cost of electrode materials. However, with the wide application of electrolytic hydrogen production, some problems have been exposed, such as high polarization overpotential, limited high current density electrolysis, high hydrogen content in oxygen, high stack cost ratio, and voltage performance decay.

[0003] In the existing technology, the electrolysis stack polarization curve under test conditions is usually used to evaluate the performance of the water electrolysis hydrogen production stack. This performance indicator can only reflect the overall electrochemical performance of the stack, and cannot reveal the performance of each single electrode sheet of the water electrolysis hydrogen production stack, nor can it detail the polarization process of each part of the electrolysis stack. In addition, electrochemical impedance analysis spectrum is also a method for analyzing the performance of the electrolysis stack. Electrochemical impedance spectrum and equivalent circuit model are generally used to analyze the electrochemical behavior of the electrolysis stack. The impedance parameters fitted by the equivalent circuit model can represent the electrochemical information of each part of the stack, such as electrode activation resistance, ohmic resistance, mass transfer resistance, and electrode aging. The electrolytic hydrogen production stack usually has a complex structure of end plate, porous electrode structure, porous diaphragm, and electrolysis bubbles, so a complex nonlinear function is needed for evaluation. However, a simple equivalent circuit model is generally universal and cannot accurately reflect a single process of electrolysis. Therefore, corresponding to the alternating current impedance spectrum under different current densities, the physical meaning of the single equivalent circuit fitting parameter cannot accurately represent the performance of each part of the electrolysis stack under the working condition, which will directly affect the accuracy of the performance evaluation of each component of the electrolysis stack. SUMMARY

[0004] Therefore, it is necessary to provide an electrolysis stack performance evaluation method, an electronic device, a storage medium and a computer program product to solve the problem of inaccurate performance evaluation of the electrolysis stack in the prior art.

[0005] The present application provides an electrolysis stack performance evaluation method, comprising:

[0006] obtaining an electrochemical impedance spectrum measured at a plurality of current densities during the operation of the electrolysis stack;

[0007] determining a characteristic frequency range of a plurality of polarization processes inside the electrolysis stack according to the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, and determining a solution ion diffusion process, a charge transfer process of the anode and the cathode, and a mass transfer process in the electrolysis stack according to the characteristic frequency range.

[0008] According to the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell, the performance of the electrolysis cell is evaluated.

[0009] Further, the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell are determined according to the characteristic frequency bands, including:

[0010] According to the variation of the wave peak of the characteristic frequency bands with the current density, the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell are determined.

[0011] Further, the characteristic frequency bands include a first frequency band representing the solution ion diffusion process in the electrolysis cell, and the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell are determined according to the variation of the wave peak of the characteristic frequency bands with the current density, including:

[0012] According to the variation of the wave peak of the first characteristic frequency band with the current density, the solution ion diffusion process in the electrolysis cell is determined.

[0013] Further, the characteristic frequency bands further include a second frequency band representing the charge transfer process of the anode and the cathode in the electrolysis cell, and the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell are determined according to the variation of the wave peak of the characteristic frequency bands with the current density, including:

[0014] According to the variation of the wave peak of the second characteristic frequency band with the current density, the charge transfer process of the anode and the cathode in the electrolysis cell is determined, and the minimum frequency of the second characteristic frequency band is greater than the maximum frequency of the first characteristic frequency band.

[0015] Further, the characteristic frequency bands further include a third frequency band representing the mass transfer process in the electrolysis cell, and the solution ion diffusion process, the charge transfer process of the anode and the cathode, and the mass transfer process in the electrolysis cell are determined according to the variation of the wave peak of the characteristic frequency bands with the current density, including:

[0016] According to the variation of the wave peak of the third characteristic frequency band with the current density, the mass transfer process in the electrolysis cell is determined, and the minimum frequency of the third characteristic frequency band is greater than the maximum frequency of the second characteristic frequency band.

[0017] Further, it further includes:

[0018] The electrolysis voltage measured at multiple current densities during the operation of the electrolysis cell is obtained, and a polarization curve is generated according to the electrolysis voltage at multiple current densities.

[0019] Still further, there is also included:

[0020] The cut-off voltage is obtained, and the total resistance of the electrolysis stack is calculated according to the cut-off voltage.

[0021] The present application provides an electronic device, comprising:

[0022] at least one processor; and,

[0023] a memory in communication with the at least one processor; wherein,

[0024] The memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the electrolysis stack performance evaluation method as described above.

[0025] The present application provides a storage medium storing computer instructions for performing all steps of the electrolysis stack performance evaluation method as described above when the computer executes the computer instructions.

[0026] The present application provides a computer program product comprising computer programs / instructions which, when executed by a processor, implement the electrolysis stack performance evaluation method as described above.

[0027] The present application determines the characteristic frequency bands of a plurality of polarization processes inside the electrolysis stack according to the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, determines the solution ion diffusion process, the charge transfer process of the cathode and anode, and the mass transfer process in the electrolysis stack according to the characteristic frequency bands, and performs performance evaluation on the electrolysis stack according to the solution ion diffusion process, the charge transfer process of the cathode and anode, and the mass transfer process in the electrolysis stack. The present application quantifies different electrochemical processes by identifying different frequencies using the relaxation time distribution method, and then analyzes the internal electrochemical characteristic indexes of the whole process of the electrolysis stack, such as the internal resistance of each component, the ion transport process, the cathode and anode reaction kinetics process, and the bubble / electrolyte transport process, to improve the performance evaluation and fault diagnosis of the electrolysis stack. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 A work flow chart of an electrolysis stack performance evaluation method according to an embodiment of the present application;

[0029] Figure 2 A work flow chart of an electrolysis stack performance evaluation method according to another embodiment of the present application;

[0030] Figure 3 A schematic diagram of the polarization voltage of the electrolysis stack under different current densities;

[0031] Figure 4 This is a schematic diagram of the electrochemical impedance spectroscopy of an electrolytic cell stack at different current densities.

[0032] Figure 5 For the electrolytic cell stack at 0.6 A cm -2 Schematic diagram of the cutoff voltage curve under current density;

[0033] Figure 6 The relaxation time distribution of the electrolytic cell stack under different current densities;

[0034] Figure 7 This is a schematic diagram of the hardware structure of an electronic device according to the present invention. Detailed Implementation

[0035] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Identical components are indicated by the same reference numerals. It should be noted that the terms "front," "rear," "left," "right," "up," and "down" used in the following description refer to directions in the accompanying drawings, while the terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0036] like Figure 1 The diagram shown is a flowchart of a method for evaluating the performance of an electrolytic cell stack according to an embodiment of the present invention, including:

[0037] Step S101: Obtain the electrochemical impedance spectrum measured at multiple current densities during the operation of the electrolytic stack;

[0038] Step S102: Based on the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, determine the characteristic frequency range of multiple polarization processes inside the electrolytic stack; based on the characteristic frequency range, determine the solution ion diffusion process, the charge transfer process of the anode and cathode, and the mass transport process in the electrolytic stack.

[0039] Step S103: Evaluate the performance of the electrolytic stack based on the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack.

[0040] Specifically, the present invention can be applied to electronic devices with processing capabilities, such as computers.

[0041] This invention evaluates the performance of an electrolytic cell stack. Preferably, the electrolytic cell stack is an alkaline water electrolytic cell stack, or simply an alkaline water electrolytic cell stack.

[0042] First, step S101 is performed to obtain the electrochemical impedance spectrum measured at multiple current densities during the operation of the electrolytic stack.

[0043] Specifically, the airtightness of the electrolytic stack was first tested, and it was activated and operated under set operating parameters. After the performance of the electrolytic stack stabilized, its performance was characterized: the electrochemical impedance spectrum of the stack was measured using an AC impedance meter at different current densities.

[0044] Then, step S102 is executed, and the characteristic frequency ranges of multiple polarization processes inside the electrolytic stack are determined according to the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum. Based on the characteristic frequency ranges, the solution ion diffusion process, the charge transfer process of the anode and cathode, and the mass transport process in the electrolytic stack are determined.

[0045] Specifically, an equivalent circuit model is constructed based on the electrochemical AC impedance spectrum. By utilizing the relaxation time distribution under different current densities, the polarization process of the impedance spectrum in each frequency band is obtained, and then the entire process of the electrolytic stack is analyzed in detail.

[0046] Finally, step S103 is performed to evaluate the performance of the electrolytic stack based on the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack.

[0047] Specifically, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack are quantitatively described, thereby enabling performance evaluation of the electrolytic stack.

[0048] This invention determines the characteristic frequency ranges of multiple polarization processes within an electrolytic stack based on the relationship between the relaxation time distribution function and the impedance data of an electrochemical impedance spectroscopy. Based on these characteristic frequency ranges, it identifies the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process within the electrolytic stack. The performance of the electrolytic stack is then evaluated based on these processes. This invention utilizes the relaxation time distribution method to quantify different electrochemical processes by identifying different frequencies. This allows for detailed analysis of the entire electrolytic stack process, including internal resistance of various components, ion transport processes, cathode and anode reaction kinetics, and bubble / electrolyte transport processes, thereby improving the performance evaluation and fault diagnosis of the electrolytic stack.

[0049] like Figure 2 The diagram shown is a flowchart of a method for evaluating the performance of an electrolytic cell stack according to another embodiment of the present invention, including:

[0050] Step S201: Obtain the electrolysis voltage at multiple current densities measured during the operation of the electrolytic stack, and generate polarization curves based on the electrolysis voltage at multiple current densities.

[0051] Step S202: Obtain the electrochemical impedance spectrum measured at multiple current densities during the operation of the electrolytic stack.

[0052] Step S203: Obtain the cutoff voltage and calculate the total resistance of the electrolytic stack based on the cutoff voltage.

[0053] Step S204: Based on the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, determine the characteristic frequency range of multiple polarization processes inside the electrolytic stack.

[0054] Step S205: Based on the changes in wave peaks of multiple characteristic frequency bands with current density, determine the solution ion diffusion process, the charge transfer process of the anode and cathode, and the mass transport process in the electrolytic stack.

[0055] In one embodiment, the characteristic frequency band includes: a first frequency band characterizing the solution ion diffusion process in the electrolytic stack; the step of determining the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0056] The solution ion diffusion process in the electrolytic stack is determined based on the change of the peak of the first characteristic frequency band with the current density.

[0057] In one embodiment, the characteristic frequency band further includes: a second frequency band characterizing the charge transfer process between the anode and cathode in the electrolytic stack, wherein determining the solution ion diffusion process, the charge transfer process between the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0058] The charge transfer process of the anode and cathode in the electrolytic stack is determined based on the change of the peak of the second characteristic frequency band with the current density, wherein the minimum frequency of the second characteristic frequency band is greater than the maximum frequency of the first characteristic frequency band.

[0059] In one embodiment, the characteristic frequency band further includes: a third frequency band characterizing the mass transport process in the electrolytic stack, wherein determining the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0060] The material transport process in the electrolytic stack is determined based on the change of the peak of the third characteristic frequency band with the current density, wherein the minimum frequency of the third characteristic frequency band is greater than the maximum frequency of the second characteristic frequency band.

[0061] Step S206: Evaluate the performance of the electrolytic stack based on the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack.

[0062] Specifically, step S201 is first executed to obtain the electrolysis voltage at multiple current densities measured during the operation of the electrolytic stack, and a polarization curve is generated based on the electrolysis voltage at multiple current densities.

[0063] Specifically, the electrolytic cell stack undergoes airtightness testing, and is activated and operated under set operating parameters. These operating parameters include: operating temperature, liquid flow rate (e.g., alkali flow rate), cathode / anode inlet pressure, cathode / anode outlet pressure, and activation current density.

[0064] After the electrolytic cell stack performance stabilizes, performance characterization will be performed: the electrolytic voltage at different current densities will be measured, and then step S201 will be executed to obtain the electrolytic voltage at multiple current densities measured during the operation of the electrolytic cell stack. Polarization curves will be plotted based on the electrolytic voltage at multiple current densities. Figure 3 The figure shows the polarization curves of the electrolytic stack under different current densities, where the horizontal axis represents the current density and the vertical axis represents the electrolytic voltage.

[0065] In some embodiments, the method further includes: analyzing the performance of the electrolytic stack based on measured polarization curves. Specifically, by comparing the polarization curves of multiple electrodes, the catalytic performance of each individual electrode in the electrolytic stack is preliminarily determined.

[0066] Then, step S202 is executed to obtain the electrochemical impedance spectrum measured at multiple current densities during the operation of the electrolytic stack.

[0067] Specifically, after the polarization curve test is completed, the electrochemical impedance spectroscopy of the electrolytic stack is measured using an AC impedance meter.

[0068] In one example, for assembling 25cm 2 Electrolytic cells at 200, 500, 1000 and 2000 mA·cm -2 Measurements were performed in constant current mode, with a frequency range of 0.1 Hz to 10 kHz. The AC perturbation current amplitude was 10-15% of the DC operating load to satisfy the linearity assumption. To ensure the accuracy of the electrochemical impedance spectroscopy (EIS) data, all frequency points were measured three times and the average value was taken. Then, step S202 was executed to obtain the electrochemical impedance spectrum. Figure 4 Electrochemical impedance spectroscopy of the electrolytic cell stack at different current densities. Figure 4 This is a Nyquist plot, representing the negative values ​​of the imaginary and real parts of the complex impedance of the electrolytic cell. The Nyquist plot has the real part on the horizontal axis and the negative values ​​of the imaginary part on the vertical axis, including 200 mA·cm. -2 Electrochemical impedance spectroscopy at 41 and 500 mA·cm -2Electrochemical impedance spectroscopy 42, 1 A·cm -2 Electrochemical impedance spectroscopy 43, 2 A·cm -2 Electrochemical impedance spectroscopy 44.

[0069] Then, step S203 is executed to obtain the cutoff voltage and calculate the total resistance of the electrolytic stack based on the cutoff voltage.

[0070] Specifically, during the test, the cutoff voltage is recorded simultaneously, and then step S203 is executed. Based on the cutoff voltage, the total resistance of the electrolytic stack is calculated according to the voltage-current relationship. The total resistance includes electronic resistance, ionic resistance, charge transfer resistance, and mass transport resistance. Figure 5 As shown, the electrolytic cell stack operates at 0.6 A·cm -2 After the current density is stabilized for a period of time, the working current is disconnected, and the change of electrolysis voltage over time is monitored. Then, a graph is plotted with the square root of time as the horizontal axis and the change of electrolysis voltage as the vertical axis. The resistance value, i.e., the total resistance, is obtained from the ratio of the intercept voltage value to the current. The total resistance includes electronic resistance, ionic resistance, and charge transfer resistance. The mass diffusion resistance coefficient can be obtained from the slope, and the mass transport resistance can be further calculated.

[0071] In some embodiments, the cutoff voltage is the open-circuit voltage of the electrolytic stack recorded after the electrochemical impedance spectroscopy test of the electrolytic stack is completed at each current density.

[0072] Specifically, the electrochemical impedance spectroscopy of the electrolytic stack was measured using an AC impedance meter at different current densities. After each current density test, the voltage change of the electrolytic stack was recorded to obtain the cutoff voltage at different current densities.

[0073] In some embodiments, the method further includes: evaluating the performance of the electrolytic stack based on its total resistance.

[0074] Specifically, the electrochemical characteristics of the electrolytic stack, such as internal resistance of each component, cathode and anode reaction kinetics, and bubble / electrolyte transport, are quantitatively described by combining the recorded cutoff voltage.

[0075] Then, step S204 is executed to determine the characteristic frequency range of multiple polarization processes inside the electrolytic stack based on the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum.

[0076] Specifically, an equivalent circuit model is constructed based on the electrochemical AC impedance spectrum. By utilizing the relaxation time distribution under different current densities, the polarization process of the impedance spectrum in each frequency band is obtained, and then the entire process of the electrolytic stack is analyzed in detail.

[0077] Specifically, the characteristic frequencies of each polarization process inside the electrolytic stack are determined based on the relationship between the relaxation time distribution function and the EIS impedance data.

[0078] Then, step S205 is executed to determine the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density.

[0079] Specifically, based on the relaxation time distribution having peaks with different shapes within different characteristic frequencies, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack are determined.

[0080] In one embodiment, the characteristic frequency band includes: a first frequency band characterizing the solution ion diffusion process in the electrolytic stack; the step of determining the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0081] The solution ion diffusion process in the electrolytic stack is determined based on the change of the peak of the first characteristic frequency band with the current density.

[0082] Specifically, the first characteristic frequency band is preferably a high-frequency band, with a frequency range > 1000 Hz. Peaks of the first frequency band are obtained at multiple current densities, and the solution ion diffusion process in the electrolytic stack is determined based on the changes in the peaks within the first frequency band with varying current densities.

[0083] In one embodiment, the characteristic frequency band further includes: a second frequency band characterizing the charge transfer process between the anode and cathode in the electrolytic stack, wherein determining the solution ion diffusion process, the charge transfer process between the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0084] The charge transfer process of the anode and cathode in the electrolytic stack is determined based on the change of the peak of the second characteristic frequency band with the current density, wherein the minimum frequency of the second characteristic frequency band is greater than the maximum frequency of the first characteristic frequency band.

[0085] Specifically, the second characteristic frequency band is preferably an intermediate frequency band, with a frequency range of 10-1000Hz. Peaks of the second frequency band are obtained at multiple current densities, and the charge transfer process between the anode and cathode in the electrolytic stack is determined based on the variation of the peaks within the second frequency band with current density.

[0086] In one embodiment, the characteristic frequency band further includes: a third frequency band characterizing the mass transport process in the electrolytic stack, wherein determining the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes:

[0087] The material transport process in the electrolytic stack is determined based on the change of the peak of the third characteristic frequency band with the current density, wherein the minimum frequency of the third characteristic frequency band is greater than the maximum frequency of the second characteristic frequency band.

[0088] Specifically, the third characteristic frequency band is preferably a low-frequency band, with a frequency range of 0.1-10Hz. Peak values ​​of the third frequency band are obtained at multiple current densities, and the mass transport process in the electrolytic stack is determined based on the variation of the peak values ​​within the third frequency band with current density.

[0089] like Figure 6 As shown, the horizontal axis represents the time constant, and the vertical axis represents the impedance contribution. The relaxation time distribution exhibits peaks of different shapes in the first characteristic frequency band (greater than 1000 Hz) 61, the second characteristic frequency band (10-1000 Hz) 62, and the third characteristic frequency band (0.1-10 Hz) 63, corresponding to ion diffusion in the solution, charge transfer between the anode and cathode, and mass transport processes in the electrolytic stack, respectively. With increasing current density, the peak value in the first characteristic frequency band 61 increases slightly. This is because the increased current density accelerates the electrochemical reaction process, leading to insufficient hydroxide ion supply, which in turn limits the electrochemical reaction rate and increases ionic resistance. The peak in the second characteristic frequency band 62 exhibits a relatively large charge transfer resistance due to insufficient current density to drive the water splitting reaction. However, with increasing current density, the charge transfer process accelerates, indicating an increased electrolysis rate and a smaller charge transfer resistance. In the third characteristic frequency band 63, with increasing current density, the number and speed of bubble generation during electrolysis increase. These bubbles accumulate on the electrode surface because they cannot be expelled in time, resulting in increased mass transport resistance.

[0090] The charge transfer process between the cathode and anode includes the charge transfer process at the cathode and the charge transfer process at the anode. Therefore, the second characteristic frequency band 62 includes two peaks, where peak 621 is the peak of the charge transfer process at the cathode, and peak 622 is the peak of the charge transfer process at the anode.

[0091] Finally, step S206 is executed to evaluate the performance of the electrolytic stack based on the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack.

[0092] Specifically, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process are determined according to different frequency bands. The peak value of each frequency band represents the impedance value of these processes. The performance of the electrolytic cell stack is quantitatively evaluated by measuring the impedance of these processes. Lower impedance values ​​indicate better performance.

[0093] Simultaneously, the electrolysis voltage obtained from the polarization curve is used to calculate the total resistance based on the cutoff voltage. Combined with the changes in current density across multiple characteristic frequency bands, the processes of ion diffusion in the solution, charge transfer at the anode and cathode, and mass transport in the electrolytic stack are determined. These three methods mutually verify and complement each other to ultimately differentiate the resistance of each component.

[0094] In some embodiments, the method further includes: performing fault diagnosis, specifically:

[0095] The electrolysis voltage obtained in advance based on the polarization curve is the normal electrolysis voltage under the corresponding current density. When the actual voltage of the stack is detected to deviate, it can be determined that the electrolysis stack has a fault.

[0096] The total resistance is calculated in advance based on the cutoff voltage as the total resistance under normal conditions. In actual operation, when the actual total resistance is found to be different from the total resistance under normal conditions, it can be determined that the electrolytic stack has malfunctioned.

[0097] In some embodiments, the method further includes: performing fault diagnosis, specifically:

[0098] Based on different frequency bands, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process are determined, and the impedances of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process are determined as the impedances under normal conditions for each process.

[0099] In the actual operation of an electrolytic cell stack, the actual impedance of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process are calculated. When the actual impedance differs from the impedance under normal conditions, the process in which the absolute value of the difference between the actual impedance and the impedance under normal conditions exceeds a preset difference threshold is identified as a fault process. This allows for accurate location of the faulty process.

[0100] This embodiment presents a method for evaluating the performance of a water electrolysis hydrogen production stack. The method involves acquiring the polarization curves and electrochemical impedance spectroscopy (EIS) of the electrolysis stack, recording the cutoff voltage, constructing an equivalent circuit model using EIS, and obtaining the polarization process of the impedance spectrum at different frequency bands using the relaxation time distribution under different current densities. This allows for a detailed analysis of the entire electrolysis stack process, including internal resistance of various components, cathode and anode reaction kinetics, bubble / electrolyte transport, and other internal electrochemical characteristics. This improves the performance evaluation and fault diagnosis of the electrolysis stack.

[0101] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0102] like Figure 7 The diagram shown is a hardware structure schematic of an electronic device according to the present invention, comprising:

[0103] At least one processor 701; and,

[0104] A memory 702 is communicatively connected to at least one of the processors 701; wherein,

[0105] The memory 702 stores instructions that can be executed by at least one of the processors to enable the at least one of the processors to perform the electrolytic cell stack performance evaluation method as described above.

[0106] Figure 7 Take the 701 processor as an example.

[0107] The electronic device may also include an input device 703 and a display device 704.

[0108] The processor 701, memory 702, input device 703 and display device 704 can be connected by a bus or other means. The figure shows an example of connection by a bus.

[0109] The memory 702, as a non-volatile computer-readable storage medium, can be used to store non-volatile software programs, non-volatile computer-executable programs, and modules, such as the program instructions / modules corresponding to the electrolytic cell stack performance evaluation method in the embodiments of this application, for example, Figure 1 , Figure 2 The method flow is shown. The processor 701 executes various functional applications and data processing by running non-volatile software programs, instructions, and modules stored in the memory 702, thereby realizing the electrolytic cell stack performance evaluation method in the above embodiments.

[0110] Memory 702 may include a program storage area and a data storage area. The program storage area may store an operating system and an application program required for at least one function. The data storage area may store data created according to the use of the electrolytic cell performance evaluation method. Furthermore, memory 702 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, or other non-volatile solid-state storage device. In some embodiments, memory 702 may optionally include memory remotely located relative to processor 701, and these remote memories may be connected via a network to the apparatus performing the electrolytic cell performance evaluation method. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0111] The input device 703 can receive user clicks and generate signal inputs related to user settings and function control for electrolytic cell performance evaluation methods. The display device 704 may include a display screen or other display equipment.

[0112] When one or more modules are stored in the memory 702, and are run by one or more processors 701, the electrolytic stack performance evaluation method in any of the above method embodiments is executed.

[0113] This invention determines the characteristic frequency ranges of multiple polarization processes within an electrolytic stack based on the relationship between the relaxation time distribution function and the impedance data of an electrochemical impedance spectroscopy. Based on these characteristic frequency ranges, it identifies the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process within the electrolytic stack. The performance of the electrolytic stack is then evaluated based on these processes. This invention utilizes the relaxation time distribution method to quantify different electrochemical processes by identifying different frequencies. This allows for detailed analysis of the entire electrolytic stack process, including internal resistance of various components, ion transport processes, cathode and anode reaction kinetics, and bubble / electrolyte transport processes, thereby improving the performance evaluation and fault diagnosis of the electrolytic stack.

[0114] One embodiment of the present invention provides a storage medium that stores computer instructions, which, when executed by a computer, are used to perform all the steps of the electrolytic cell stack performance evaluation method described above.

[0115] In the context of this disclosure, a storage medium can be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, apparatus, or device. The storage medium can be a machine-readable signal medium or a machine-readable storage medium. Optionally, the storage medium can be a non-transitory computer-readable storage medium, such as a ROM, random access memory (RAM), compact disc ROM (CD-ROM), magnetic tape, floppy disk, and optical data storage device.

[0116] One embodiment of the present invention provides a computer program product, including a computer program / instructions, which, when executed by a processor, implements the electrolytic cell stack performance evaluation method as described above.

[0117] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A method for evaluating the performance of an electrolytic cell stack, characterized in that, include: Obtain electrochemical impedance spectra measured at multiple current densities during the operation of the electrolytic cell stack; Based on the relationship between the relaxation time distribution function and the impedance data of the electrochemical impedance spectrum, the characteristic frequency ranges of multiple polarization processes inside the electrolytic stack are determined. Based on the characteristic frequency ranges, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack are determined. The performance of the electrolytic stack is evaluated based on the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack.

2. The method for evaluating the performance of an electrolytic cell stack according to claim 1, characterized in that, The determination of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the characteristic frequency band includes: Based on the changes in wave peaks with current density across multiple characteristic frequency bands, the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack are determined.

3. The method for evaluating the performance of an electrolytic cell stack according to claim 2, characterized in that, The characteristic frequency bands include: a first frequency band characterizing the solution ion diffusion process in the electrolytic stack; the determination of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes: The solution ion diffusion process in the electrolytic stack is determined based on the change of the peak of the first characteristic frequency band with the current density.

4. The method for evaluating the performance of an electrolytic cell stack according to claim 3, characterized in that, The characteristic frequency band further includes a second frequency band characterizing the charge transfer process at the anode and cathode in the electrolytic stack. The determination of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes: The charge transfer process of the anode and cathode in the electrolytic stack is determined based on the change of the peak of the second characteristic frequency band with the current density, wherein the minimum frequency of the second characteristic frequency band is greater than the maximum frequency of the first characteristic frequency band.

5. The method for evaluating the performance of an electrolytic cell stack according to claim 4, characterized in that, The characteristic frequency band further includes a third frequency band characterizing the mass transport process in the electrolytic stack. The determination of the solution ion diffusion process, the charge transfer process at the anode and cathode, and the mass transport process in the electrolytic stack based on the changes in the peaks of multiple characteristic frequency bands with current density includes: The material transport process in the electrolytic stack is determined based on the change of the peak of the third characteristic frequency band with the current density, wherein the minimum frequency of the third characteristic frequency band is greater than the maximum frequency of the second characteristic frequency band.

6. The method for evaluating the performance of an electrolytic cell stack according to any one of claims 1 to 5, characterized in that, Also includes: The electrolysis voltage at multiple current densities measured during the operation of the electrolytic stack is obtained, and polarization curves are generated based on the electrolysis voltage at multiple current densities.

7. The method for evaluating the performance of an electrolytic cell stack according to any one of claims 1 to 5, characterized in that, Also includes: Obtain the cutoff voltage and calculate the total resistance of the electrolytic stack based on the cutoff voltage.

8. An electronic device, characterized in that, include: At least one processor; as well as, A memory communicatively connected to at least one of the processors; wherein, The memory stores instructions that can be executed by at least one of the processors to enable at least one of the processors to perform the electrolytic cell stack performance evaluation method as described in any one of claims 1 to 7.

9. A storage medium, characterized in that, The storage medium stores computer instructions, which, when executed by the computer, are used to perform all the steps of the electrolytic cell stack performance evaluation method as described in any one of claims 1 to 7.

10. A computer program product comprising a computer program / instructions, characterized in that, When the computer program / instructions are executed by the processor, they implement the electrolytic stack performance evaluation method as described in any one of claims 1 to 7.

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