Water electrolysis cell monitoring device, water electrolysis system and water electrolysis cell monitoring method

Abstract

The embodiment of the invention discloses a water electrolysis cell monitoring device, a water electrolysis system and a water electrolysis cell monitoring method.The water electrolysis cell monitoring device is used for conducting potential monitoring on a water electrolysis cell, the water electrolysis cell is provided with an electrolyte outlet, and the water electrolysis cell monitoring device comprises a shell, a water storage tank and a water storage tank, the shell is provided with an ion inlet communicated with the accommodating cavity, and the ion inlet is configured to be connected with the electrolyte outlet; the ion exchange part comprises an electrolyte membrane, and the electrolyte membrane is arranged between the ion inlet and the electrolyte outlet, so that ions in the electrolyte enter the accommodating cavity through the electrolyte membrane; the reference electrode is provided with an electrode body, and the electrode body is inserted into the accommodating cavity so as to extend into the electrolyte. By arranging the electrolyte membrane, liquid mixing and gas permeation between the water electrolysis tank and the monitoring device can be blocked, so that the long-term stability of the reference electrode is guaranteed.

Description

Technical Field

[0001] This application relates to the field of water electrolysis technology, specifically to a water electrolysis cell monitoring device, a water electrolysis system, and a water electrolysis cell monitoring method. Background Technology

[0002] In the research and application of anion exchange membranes (AEMs), failure analysis is a crucial step in ensuring their performance and stability. In-situ analytical techniques include in-situ Raman spectroscopy and in-situ differential electrochemical mass spectrometry (DEMS), but each technique has its own limitations. In-situ Raman spectroscopy has limitations in detecting trace gases reacting or released during battery cycling, making it difficult to accurately capture some key failure factors. While DEMS can detect changes in gaseous reactants or products during electrochemical reactions, the equipment is complex, expensive, and has extremely high requirements for experimental environment and operation, hindering its widespread application in practical production and research.

[0003] Using reference electrodes for AEM single-cell failure analysis also faces many challenges. Among the related technologies, the integration of reference electrodes mainly includes two forms: one is to directly insert the reference electrode into the electrolyzer or separator, which is susceptible to bubble interference, resulting in insufficient long-term stability; the other is to construct a separate chamber with the reference electrode through an epitaxial film, which has insufficient anti-fouling properties, resulting in insufficient long-term stability. Summary of the Invention

[0004] This application provides a water electrolysis cell monitoring device, a water electrolysis system, and a water electrolysis cell monitoring method, aiming to solve the problem of insufficient long-term stability in AEM single-cell failure analysis.

[0005] This application provides a water electrolysis cell monitoring device for monitoring the potential of a water electrolysis cell, wherein the water electrolysis cell has an electrolyte outlet, and the water electrolysis cell monitoring device includes: The housing has a cavity for containing electrolyte, and the housing has an ion inlet communicating with the cavity, the ion inlet being configured to be connected to the electrolyte outlet; An ion exchange component includes an electrolyte membrane disposed between the ion inlet and the electrolyte outlet, so that ions in the electrolyte can pass through the electrolyte membrane into the receiving cavity. A reference electrode has an electrode body that is inserted into the receiving cavity to extend into the electrolyte.

[0006] Optionally, in some embodiments of this application, the water electrolysis cell further includes an electrolyte inlet and an electrolyte circulation pipeline, the electrolyte circulation pipeline connecting the electrolyte outlet and the electrolyte inlet; the ion inlet is configured to be connected to the electrolyte circulation pipeline via a three-way valve; wherein, the electrolyte membrane is disposed between the three-way valve and the ion inlet.

[0007] Optionally, in some embodiments of this application, the electrolyte membrane is an anion exchange membrane; and / or The electrolyte membrane has a diameter of 5mm-10mm; and / or The thickness of the electrolyte membrane is ≤80μm; and / or The electrolyte membrane has an ionic conductivity > 0.1 S / cm.

[0008] Optionally, in some embodiments of this application, the surface of the electrolyte membrane is inclined in the horizontal direction.

[0009] Optionally, in some embodiments of this application, the angle between the surface of the electrolyte membrane and the horizontal direction is 30°-60°.

[0010] Optionally, in some embodiments of this application, the ion exchange component further includes a support portion, which is stacked on at least one side of the electrolyte membrane.

[0011] Optionally, in some embodiments of this application, the support portion has pores extending along the thickness direction of the electrolyte membrane; Wherein, the porosity of the support portion is 40%-60%; and / or The pore size is ≤20μm; and / or The thickness of the support portion is 50μm-150μm; and / or The compressive strength of the support is >50MPa; and / or The material of the support includes one or more of nickel, titanium, and stainless steel.

[0012] Optionally, in some embodiments of this application, a pressure compensator is also included, which is disposed in the housing to control the pressure within the receiving cavity.

[0013] Accordingly, this application also provides a water electrolysis system, comprising: A water electrolysis cell with an electrolyte outlet; The aforementioned water electrolysis cell monitoring device.

[0014] Optionally, in some embodiments of this application, a pressure control device is also included; The pressure control device includes a first pressure sensor and a second pressure sensor, which are configured to monitor the pressure across the electrolyte membrane, respectively; and / or The pressure control device includes a back pressure valve configured to control the pressure within the water electrolysis cell.

[0015] Optionally, in some embodiments of this application, a clamping device is further provided on both sides of the ion exchange component facing the ion inlet and facing the electrolyte outlet, so as to fix the ion exchange component between the ion inlet and the electrolyte outlet.

[0016] Furthermore, this application also provides a method for monitoring a water electrolysis cell, applied to the aforementioned water electrolysis system, wherein the water electrolysis cell monitoring method includes: Monitor the potential of the anode and / or cathode of the water electrolysis cell relative to the reference electrode.

[0017] Optionally, in some embodiments of this application, the method further includes: measuring the conductivity of the electrolyte within the receiving cavity; When the conductivity is less than or equal to a preset percentage of the initial value of the conductivity, a membrane fouling alarm is triggered and / or the electrolyte membrane is cleaned.

[0018] Optionally, in some embodiments of this application, the preset percentage is 80%.

[0019] Optionally, in some embodiments of this application, the method further includes: controlling the pressure difference across the electrolyte membrane to be less than or equal to a pressure difference threshold; and / or The electrolyte flow rate at the membrane interface on the side of the electrolyte membrane facing the electrolyte outlet is controlled to be greater than or equal to a flow rate threshold.

[0020] Optionally, in some embodiments of this application, the differential pressure threshold is 0.3 bar; and / or The flow rate threshold is 0.5 m / s.

[0021] This application, by installing a monitoring device outside the water electrolysis cell, enables real-time and precise monitoring of the cell voltage changes at the cathode and anode during normal operation, allowing for analysis and diagnosis of potential failures. By installing an electrolyte membrane, a micron-level ion channel can be formed between the water electrolysis cell and the monitoring device's containment cavity, allowing free ion migration for potential synchronization (accurately measuring the potential changes of the working electrode). Simultaneously, it blocks liquid mixing and gas permeation (such as oxygen bubbles and metal ions) between the water electrolysis cell and the monitoring device, keeping impurities in the electrolyte outside the monitoring device's containment cavity, thus ensuring the long-term stability of the reference electrode. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the water electrolysis system provided in the embodiments of this application; Figure 2 yes Figure 1 A magnified view of a portion of the image; Figure 3 This is a schematic diagram of the control device for a water electrolysis system provided in an embodiment of this application.

[0024] Explanation of reference numerals in the attached drawings: Shell-1; Receiving cavity-11; Ion inlet-12; Ion exchange component-2; Electrolyte membrane-21; Support-22; Reference electrode-3; Electrode body-31; Pressure compensator-4; Controller-5; Water electrolysis cell-6; Electrolyte circulation pipeline-61; Electrolyte inlet-62; Electrolyte outlet-63; Three-way valve-7; First pressure sensor-8; Second pressure sensor-9; Back pressure valve-10. Detailed Implementation

[0025] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] In related technologies, the integration of reference electrodes mainly includes two forms: one is to directly insert the reference electrode into the electrolytic cell or separator, which is susceptible to bubble interference and difficult to adapt to high-voltage systems; the other is to construct a separate chamber with the reference electrode through an epitaxial film, which has problems such as poor high-voltage adaptability, insufficient anti-pollution, slow dynamic response, and serious voltage drift.

[0027] This application provides a water electrolysis cell monitoring device, a water electrolysis system, and a water electrolysis cell monitoring method. These are described in detail below. It should be noted that the order of description of the following embodiments is not intended to limit the preferred order of the embodiments. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative and do not impose numerical requirements or establish an order. Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single digits within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any referenced number (fraction or integer) within the indicated range.

[0028] Please see Figure 1 and Figure 2 This application provides a water electrolysis cell monitoring device for monitoring the potential of a water electrolysis cell 6. The water electrolysis cell 6 has an electrolyte outlet 63. The water electrolysis cell monitoring device includes: The housing 1 has a receiving cavity 11 for containing electrolyte, and the housing 1 has an ion inlet 12 communicating with the receiving cavity 11. The ion inlet 12 is configured to be connected to the electrolyte outlet 63. The ion exchange component 2 includes an electrolyte membrane 21, which is disposed between the ion inlet 12 and the electrolyte outlet 63, so that ions in the electrolyte can pass through the electrolyte membrane 21 into the receiving cavity 11. The reference electrode 3 has an electrode body 31, which is inserted into the receiving cavity 11 to extend into the electrolyte.

[0029] In this application, the ion inlet 12 of the water electrolysis cell monitoring device is connected to the electrolyte outlet 63 of the water electrolysis cell 6, and an electrolyte membrane 21 is provided between the ion inlet 12 and the electrolyte outlet 63 of the water electrolysis cell 6, thereby allowing the OH generated during the operation of the water electrolysis cell 6 to be properly ionized. -Ions migrate through the electrolyte membrane 21 into the electrolyte in the containment cavity 11 of the monitoring device, forming an ion current path (non-electronic path), thereby establishing a stable potential difference between the reference electrode 3 and the working electrode of the water electrolysis cell 6. By installing a monitoring device outside the water electrolysis cell 6, the cell voltage changes of its cathode and anode can be monitored in real time and accurately during normal operation of the water electrolysis cell 6, so as to analyze and diagnose the cause of its failure. This provides strong technical support for improving the performance of AEM single cells, extending their lifespan, and ensuring stability in practical applications. By setting up an electrolyte membrane 21, a micron-level ion channel can be formed between the water electrolysis cell 6 and the receiving cavity 11 of the monitoring device, allowing ions to migrate freely to achieve potential synchronization (accurately measuring the potential change of the working electrode). At the same time, it blocks liquid mixing and gas permeation (such as oxygen bubbles, metal ions, etc.) between the water electrolysis cell 6 and the monitoring device, and keeps impurities in the electrolyte in the water electrolysis cell 6 outside the receiving cavity 11 of the monitoring device, thereby ensuring the long-term stability of the reference electrode 3. During the monitoring process, ions only need to pass through the electrolyte membrane 21, resulting in a short migration path and a short potential feedback delay (less than 1 second).

[0030] It is understandable that the electrolyte in water electrolysis cell 6 may contain heavy metal ions (such as Fe). 3+ Cu 2+ ), sulfides (such as S) 2- Impurities such as catalyst powder and hydrogen bubbles can chemically contaminate the reference electrode 3, causing permanent damage and rendering the reference potential provided by the reference electrode 3 ineffective, thus distorting the monitoring data of the monitoring device. The electrolyte in the water electrolysis cell 6 may contain particulate matter (such as catalyst powder) and evolved gases (such as oxygen and hydrogen bubbles), which can block the liquid junction of the reference electrode 3 or form a gas film, leading to unstable signals, high noise, delayed response, and transient failure of the reference electrode 3. Impurities in the electrolyte in the water electrolysis cell 6 may cause the liquid junction potential of the reference electrode 3 to drift and decrease in stability, resulting in slow, systematic errors, a gradual decrease in measurement accuracy, and difficulty in detection and correction. Due to the electrochemical reaction in the water electrolysis cell 6, there is a difference in ion concentration near the membrane interface on both sides of the electrolyte membrane 21. Driven by the ion concentration gradient on both sides of the electrolyte membrane 21, ion diffusion and potential synchronization are achieved, while having a relatively small impact on the electrolyte concentration of the water electrolysis cell 6.

[0031] It is understood that the ion inlet 12 and the electrolyte outlet 63 are connected by a pipeline, and the electrolyte membrane 21 is disposed between the ion inlet 12 and the electrolyte outlet 63. The electrolyte membrane 21 can be disposed at the ion inlet 12, at the electrolyte outlet 63, or embedded in the pipeline between the ion inlet 12 and the electrolyte outlet 63. As an example, the electrolyte membrane 21 is typically disposed at the ion inlet 12.

[0032] It is understood that the water electrolysis cell 6 in this application can be an anion exchange membrane water electrolysis cell. The electrolyte membrane 21 is a solid electrolyte membrane.

[0033] Optionally, in some embodiments of this application, the water electrolysis cell 6 further includes an electrolyte inlet 62 and an electrolyte circulation pipeline 61, the electrolyte circulation pipeline 61 connecting the electrolyte outlet 63 and the electrolyte inlet 62; the ion inlet 12 is configured to be connected to the electrolyte circulation pipeline 61 via a three-way valve 7; wherein, the electrolyte membrane 21 is disposed between the three-way valve 7 and the ion inlet 12.

[0034] In this application, the monitoring device is connected to the electrolyte circulation pipeline 61 of the water electrolysis cell 6 via a three-way valve 7. When the electrolyte circulates in the electrolyte circulation pipeline 61, and the electrolyte flows through the three-way valve 7, the OH- in the electrolyte... - Ions migrate through the electrolyte membrane 21 into the electrolyte in the containment cavity 11 of the monitoring device, forming an ion current path. This allows the reference electrode 3 and the working electrode to establish a stable potential difference, thereby synchronizing the potential of the reference electrode 3 with that of the working electrode of the water electrolysis cell 6, thus improving the response time and monitoring accuracy of the monitoring device.

[0035] It is understood that the ion inlet 12 is connected to the electrolyte circulation pipeline 61 via a three-way valve 7. That is, the ion inlet 12 of the reference device is connected to the electrolyte outlet 63 and electrolyte inlet 62 of the water electrolysis cell 6 via the three-way valve 7. The ion inlet 12 and the three-way valve 7 are connected by a pipeline, and the electrolyte membrane 21 is disposed between the three-way valve 7 and the ion inlet 12. That is, the electrolyte membrane 21 is disposed between the port where the three-way valve 7 connects to the ion inlet 12 and the ion inlet 12.

[0036] As an example, the electrolyte membrane 21 is embedded at the ion inlet 12.

[0037] Optionally, in some embodiments of this application, the inner diameter of the electrolyte circulation pipeline 61 is greater than or equal to the inner diameter of the pipeline between the three-way valve 7 and the ion inlet 12. Thus, by adjusting the inner diameters of the electrolyte circulation pipeline 61 and the pipeline between the three-way valve 7 and the ion inlet 12, the electrolyte flow rate in the pipeline between the three-way valve 7 and the ion inlet 12 can be made greater than or equal to the electrolyte flow rate in the electrolyte circulation pipeline 61, thereby controlling the electrolyte flow rate at the membrane interface of the electrolyte membrane 21 facing the electrolyte outlet 63.

[0038] As an example, the inner diameter of the electrolyte circulation pipe 61 is 10 mm, and the inner diameter and length of the pipe between the three-way valve 7 and the ion inlet 12 are ≤1.5 mm and ≤10 mm, which can increase the flow rate of the electrolyte entering the pipe between the three-way valve 7 and the ion inlet 12 from the electrolyte circulation pipe 61.

[0039] Optionally, in some embodiments of this application, the electrolyte membrane is an anion exchange membrane.

[0040] Optionally, in some embodiments of this application, the diameter of the electrolyte membrane 21 is 5mm-10mm, for example, it can be 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, etc. In this way, the electrolyte membrane 21 can have sufficient ion flux, mechanical strength and good concentration uniformity, while allowing the monitoring device to be miniaturized and more easily integrated into the compact piping or structure of an industrial electrolyzer.

[0041] Understandably, the ion flux of the electrolyte membrane 21 is proportional to its cross-sectional area (i.e., the square of its diameter). If the diameter is too small, the resistance of the electrolyte membrane 21 will be large, which will lead to response delay and weak signal. Under the same pressure, the larger the area of ​​the electrolyte membrane 21, the greater the total force it experiences. If the diameter of the electrolyte membrane 21 is too large, there will be mechanical risks (deformation and rupture at the center of the membrane) and concentration gradients (local concentration differences exist in the electrolyte membrane 21, thus introducing measurement errors).

[0042] Optionally, in some embodiments of this application, the thickness H1 of the electrolyte membrane 21 is ≤ 80 μm, for example, it can be 80 μm, 75 μm, 70 μm, 65 μm, 60 μm, 55 μm, 50 μm, etc. This shortens the ion migration path, which is only the thickness H1 of the electrolyte membrane 21, thereby improving the response speed of the reference electrode 3, reducing the potential feedback delay time to <1 s, and simultaneously reducing the impedance of the electrolyte membrane 21, decreasing measurement error, reducing liquid junction potential, and improving the mechanical stress distribution of the electrolyte membrane 21.

[0043] Optionally, in some embodiments of this application, the ionic conductivity of the electrolyte membrane 21 is >0.1 S / cm.

[0044] It is understandable that the higher the conductivity of the electrolyte membrane 21, the smoother the ion migration and the lower the impedance. By using an electrolyte membrane 21 with an ionic conductivity > 0.1 S / cm, the electrolyte membrane 21 can have low impedance and improve the ion migration speed.

[0045] Optionally, in some embodiments of this application, the OH of the electrolyte membrane 21 is... - Migration number ≥ 0.90.

[0046] Understandably, under the influence of an electric field, multiple ions migrate together through the electrolyte membrane 21 to form an electric current, OH... - Migration number refers to OH - The proportion of the current carried to the total current, OH - A migration number ≥ 0.90 means that more than 90% of the current is generated by OH. - Carrier. By controlling OH - The transference number ensures accurate transmission of potential signals; if OH - A low migration number indicates the presence of a large number of "noisy ions" (such as K+). + These noise ions also participate in conductivity, creating unstable and unpredictable concentration gradients and liquid junction potentials across the electrolyte membrane 21, thus reducing the accuracy of the monitoring device. High OH - Electrolyte membrane migration number 21 for OH - It has high selectivity and can effectively block K + The permeation of cations can improve the purity of the electrolyte in the containment chamber 11, thereby improving the accuracy of the test results and providing a basis for OH... - Establish a "fast dedicated channel" to achieve millisecond-level rapid response.

[0047] Optionally, in some embodiments of this application, the electrolyte membrane 21 is an anion exchange membrane.

[0048] As an example, the anion exchange membrane can be an ALkymer anion exchange membrane, an Ionomr anion exchange membrane, or a Versogen anion exchange membrane.

[0049] Optionally, in some embodiments of this application, the surface of the electrolyte membrane 21 is inclined in the horizontal direction.

[0050] It is understandable that by tilting the surface of the electrolyte membrane 21 in the horizontal direction, the force state of the bubbles can be changed, thereby using buoyancy to automatically remove the bubbles from the surface of the electrolyte membrane 21. At the same time, the tilt angle design allows the electrolyte to generate a "scouring-lifting" composite flow field when flowing over the surface of the electrolyte membrane 21. This flow field will generate a shear force on the bubbles, "sweeping" them away from the membrane surface and preventing them from staying and agglomerating into large bubbles. Bubbles are difficult to maintain a stable state on an inclined surface. Compared with a horizontal surface, on an inclined surface, bubbles need to overcome greater resistance to "lie" on the membrane surface, reducing their adhesion stability and thus reducing the effective area for bubble adhesion.

[0051] Understandably, bubbles are electrical insulators. When bubbles cover the membrane surface, they block the channels for ion migration, potentially causing signal abrupt changes / jumps and complete measurement interruptions. Because ions cannot migrate through the bubble-covered areas, the current density concentrates entirely in the remaining pathways, which may lead to excessively high local current density. This could result in membrane overheating, degradation, and irreversible performance decline. The random appearance and disappearance of bubbles cause dynamic changes in the impedance of the ion migration path, leading to uncorrectable systematic errors. Therefore, maintaining a clean, bubble-free membrane-liquid interface can stabilize and predict the impedance of the ion migration path, ensuring the continuity and accuracy of potential measurements and reducing the probability of local hot spots and thermal degradation in the electrolyte membrane 21.

[0052] Optionally, in some embodiments of this application, the angle α between the surface of the electrolyte membrane 21 and the horizontal direction is 30°-60°, for example, it can be 30°, 35°, 40°, 45°, 50°, 60°, etc.

[0053] Understandably, by making the angle α between the surface of the electrolyte membrane 21 and the horizontal direction 30°-60°, the buoyancy component along the membrane surface and the fluid shear force acting on the bubble can achieve the best synergistic effect, enabling the bubble to be efficiently "sweeped" away from the surface of the electrolyte membrane 21 with the shortest path. If the angle α between the surface of the electrolyte membrane 21 and the horizontal direction is too small, the membrane surface is too horizontal, the bubble movement path is too long, the removal efficiency is low, and it occupies a large membrane surface space. If the angle α between the surface of the electrolyte membrane 21 and the horizontal direction is too large, the membrane surface is too vertical, the effective component of buoyancy is weakened, and the bubble removal ability decreases.

[0054] Optionally, in some embodiments of this application, the ion exchange component 2 further includes a support portion 22, which is stacked on at least one side of the electrolyte membrane 21. Thus, the support portion 22 can provide support for the electrolyte membrane 21, thereby improving the pressure resistance and service life of the electrolyte membrane 21.

[0055] Understandably, the electrolyte membrane 21 may creep or even rupture under hydraulic pressure. The support 22 can bear most of the mechanical load, thus controlling the deformation of the electrolyte membrane 21 within its elastic range. At the same time, when external pressure fluctuates, the electrolyte membrane 21 is prone to stress concentration and tearing in local areas (especially at the edge fixing points). The support 22 disperses the point load or line load into uniform stress on a surface, greatly improving the pressure fatigue life of the electrolyte membrane 21.

[0056] As an example, the support 22 is a porous metal support 22 disposed on at least one side of the electrolyte membrane 21.

[0057] Optionally, in some embodiments of this application, the support portion 22 has pores extending along the thickness direction of the electrolyte membrane 21, and the porosity of the support portion 22 is 40%-60%, for example, 40%, 45%, 50%, 55%, 60%, etc., and the pore diameter is ≤20μm, for example, 20μm, 19μm, 18μm, 17μm, 16μm, 15μm, etc.

[0058] Understandably, controlling the pore size of the support portion 22 can prevent the electrolyte membrane 21 from "creeping out". The small pore size combined with the high porosity of the support portion 22 can provide a low-torsion ion migration path while ensuring high mechanical strength, thereby giving the electrolyte membrane 21 a high and uniform ionic conductivity. At the same time, the pores of the support portion 22 can filter catalyst particles, solution precipitates or other suspended impurities that may be contained in the electrolyte in the water electrolysis cell 6, thereby preventing most microscopic particles from directly contacting and scratching or contaminating the surface of the electrolyte membrane 21, thus extending the working life of the electrolyte membrane 21.

[0059] Optionally, in some embodiments of this application, the thickness H2 of the support portion 22 is 50μm-150μm, for example, it can be 50μm, 60μm, 70μm, 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, etc. This provides sufficient support for the electrolyte membrane while ensuring that ions can pass through the support portion quickly.

[0060] Optionally, in some embodiments of this application, the compressive strength of the support portion 22 is >50MPa.

[0061] Optionally, in some embodiments of this application, the material of the support portion 22 includes one or more of nickel, titanium, and stainless steel.

[0062] Optionally, in some embodiments of this application, the ion exchange component 2 is fixed between the ion inlet 12 and the electrolyte outlet 63, and a pressure-resistant sealing ring is provided between the ion exchange component 2 and the ion inlet 12 and / or between the ion exchange component 2 and the electrolyte outlet 63.

[0063] Understandably, by setting a pressure-resistant sealing ring, the electrolyte in the water electrolysis cell 6 (high-pressure side) can be isolated from the receiving cavity 11 of the monitoring device (low-pressure side) under high pressure. The pressure-resistant sealing ring utilizes its elasticity and plasticity to generate a sealing deformation under pressure, thereby achieving a leak-proof function. As an example, the pressure-resistant sealing ring is located on the side of the support 22 facing away from the electrolyte membrane 21, and the pressure-resistant sealing ring can be a fluororubber O-ring. The ion exchange component 2 is typically located at the ion inlet 12.

[0064] Optionally, in some embodiments of this application, a pressure compensator 4 is also included, which is disposed in the housing 1 to control the pressure within the receiving cavity 11. Thus, the pressure compensator 4 can dynamically balance the pressure on both sides of the electrolyte membrane 21, preventing deformation and rupture of the electrolyte membrane 21, and simultaneously enabling the monitoring device to be adapted to industrial-grade high-pressure electrolytic cells (e.g., 30 bar).

[0065] Understandably, the pressure compensator 4 is usually located at the top of the housing 1.

[0066] As an example, the pressure compensator 4 can be a piston pressure compensator 4 or a bellows pressure compensator 4. The piston pressure compensator 4 includes a piston and a pressure sensor, while the bellows pressure compensator 4 includes a bellows and a pressure sensor.

[0067] Please see Figure 3 Optionally, in some embodiments of this application, a controller 5 is further included, which is communicatively connected to the pressure compensator 4. Thus, the controller 5 can control the pressure compensator 4 in real time to adjust the pressure within the receiving cavity 11, ensuring that the pressure difference between it and the electrolyte outlet 63 is less than 0.3 bar.

[0068] As an example, controller 5 can be PLC controller 5.

[0069] Please see Figure 1 This application also provides a water electrolysis system, comprising: Water electrolysis cell 6, with an electrolyte outlet 63; The aforementioned water electrolysis cell monitoring device.

[0070] Please see Figure 3 Optionally, in some embodiments of this application, a pressure control device is also included, which includes a first pressure sensor 8 and a second pressure sensor 9, the first pressure sensor 8 and the second pressure sensor 9 being configured to monitor the pressure on both sides of the electrolyte membrane 21, respectively.

[0071] As an example, the first pressure sensor 8 can be installed in the electrolyte circulation pipeline 61, and the second pressure sensor 9 can be installed on the housing 1 of the water electrolysis cell monitoring device.

[0072] Please see Figure 3 Optionally, in some embodiments of this application, the first pressure sensor 8 and the second pressure sensor 9 are communicatively connected to the pressure compensator 4.

[0073] It is understandable that the pressure on both sides of the electrolyte membrane 21 can be monitored by the first pressure sensor 8 and the second pressure sensor 9. The pressure compensator 4 can adjust the pressure in the receiving cavity 11 according to the pressure data measured by the first pressure sensor 8 and the second pressure sensor 9, thereby controlling the pressure difference on both sides of the electrolyte membrane 21.

[0074] Please see Figure 3 Optionally, in some embodiments of this application, the pressure control device includes a back pressure valve 10, which is configured to control the pressure within the water electrolysis cell 6.

[0075] Please see Figure 3 Optionally, in some embodiments of this application, the first pressure sensor 8 is used to monitor the pressure inside the water battery, and the back pressure valve 10 is communicatively connected to the first pressure sensor 8.

[0076] Understandably, the back pressure valve 10 can adjust the pressure inside the water battery based on the data measured by the first pressure sensor 8.

[0077] As an example, the back pressure valve 10 can be installed on the gas outlet pipe of the gas-liquid separator connected to the water electrolysis cell 6.

[0078] Optionally, in some embodiments of this application, a clamping device is further provided on both sides of the ion exchange component 2 facing the ion inlet 12 and facing the electrolyte outlet 63, so as to fix the ion exchange component 2 between the ion inlet 12 and the electrolyte outlet 63.

[0079] It is understandable that the clamping device can press and fix the electrolyte membrane 21, the support part 22 and the pressure-resistant sealing ring between the ion inlet 12 and the electrolyte outlet 63, thereby achieving a sealed connection between the ion inlet 12 and the electrolyte outlet 63.

[0080] As an example, the clamping device is a rotary buckle (such as a Cam-Lock structure), one end of which is fixed to the interface flange or fixing collar of the electrolyte circulation pipeline 61, and the other end engages with the slot or lug on the housing 1 of the monitoring device. In this way, the electrolyte membrane 21, the support 22 and the pressure-resistant sealing ring can be quickly replaced and maintained.

[0081] Please see Figure 1 This application also provides a method for monitoring a water electrolysis cell, applied to the above-mentioned water electrolysis system. The method for monitoring the water electrolysis cell includes: Monitor the potential of the anode and / or cathode of the water electrolysis cell 6 relative to the reference electrode 3.

[0082] As an example, the anode and cathode potentials of the water electrolysis cell 6 and the potential of the reference electrode 3 can be monitored by an electrochemical workstation.

[0083] Understandably, the containment cavity 11 is filled with an electrolyte. For example, the electrolyte in the containment cavity 11 can be a 0.1M KCl solution or a saturated KOH solution. The 0.1M KCl solution is suitable for an Ag / AgCl reference electrode, while the saturated KOH solution is suitable for a Hg / HgO reference electrode. By matching the electrolyte in the containment cavity 11 with the reference electrode 3, a pure and chemically compatible protective environment can be provided for the reference electrode 3, thereby reducing the probability of damage to the reference electrode 3. This allows the reference electrode 3 to output a known and constant reference potential and stabilize the liquid junction potential, thus improving the measurement accuracy of the monitoring device.

[0084] Optionally, in some embodiments of this application, the method further includes: controlling the pressure difference across the electrolyte membrane 21 to be less than or equal to a pressure difference threshold.

[0085] It is understandable that if the pressure difference across the electrolyte membrane 21 is too large, it will cause the electrolyte membrane to deform and rupture. By controlling the pressure difference across the electrolyte membrane 21, its service life can be extended.

[0086] Optionally, in some embodiments of this application, the differential pressure threshold is 0.3 bar.

[0087] Understandably, when the water electrolysis cell is operating at high pressure (e.g., 30 bar), the pressure difference across the electrolyte membrane can be balanced by a pressure compensator to prevent the electrolyte membrane from deforming and rupturing.

[0088] Optionally, in some embodiments of this application, the electrolyte flow rate at the membrane interface of the electrolyte membrane 21 on the side facing the electrolyte outlet 63 is controlled to be greater than or equal to a flow rate threshold.

[0089] Optionally, in some embodiments of this application, the flow rate threshold is 0.5 m / s.

[0090] Understandably, fluids with a flow rate > 0.5 m / s can generate strong shearing and scouring effects, which can reduce the thickness of the diffusion boundary layer at the membrane interface of the electrolyte membrane 21 facing the electrolyte outlet 63 to the micrometer level, increase the interfacial ion renewal rate, and improve the mass transfer rate of the electrolyte membrane 21. This makes the ion concentration at the membrane interface more consistent with the ion concentration in the electrolyte circulation pipeline 61, thereby eliminating the concentration gradient and suppressing the liquid junction potential. The fluid shear force exerted by the fluid with a flow rate > 0.5 m / s on the attached bubbles is greater than the surface adsorption force of the bubbles, which can sweep the bubbles away from the membrane surface of the electrolyte membrane 21 in time, thereby preventing bubbles from remaining on the membrane surface of the electrolyte membrane 21 and ensuring the continuity of the monitoring signal. The higher flow rate can form an effective "self-cleaning" flow field, reducing the deposition of contaminants on the membrane surface of the electrolyte membrane 21, thereby extending the life of the electrolyte membrane 21.

[0091] Optionally, in some embodiments of this application, the method further includes: measuring the conductivity of the electrolyte within the receiving cavity 11; When the conductivity is less than or equal to a preset percentage of the initial value of the conductivity, a membrane fouling alarm is triggered and / or the electrolyte membrane 21 is cleaned.

[0092] Understandably, as the water electrolysis cell 6 operates, contaminants (such as metal hydroxides and colloidal particles) in the water electrolysis cell 6 will adhere to the surface of the electrolyte membrane 21, causing a decrease in the ion conductivity of the electrolyte membrane 21, which in turn will decrease the conductivity of the electrolyte in the containment chamber 11. When the conductivity of the electrolyte in the containment chamber 11 drops to a preset percentage of the initial value, the ion conductivity of the electrolyte membrane 21 is restored by triggering a membrane fouling alarm and / or cleaning the electrolyte membrane 21, thereby improving the measurement accuracy and extending the service life of the monitoring device.

[0093] Optionally, in some embodiments of this application, the preset percentage is 80%.

[0094] Understandably, when the conductivity of the electrolyte in the containment chamber 11 is less than or equal to 80% of the initial value, it indicates that contaminants (such as metal hydroxides and colloidal particles) in the water electrolysis cell 6 adhere to the surface of the electrolyte membrane 21, forming an insulating or semi-insulating covering layer, which reduces the ion conductivity of the electrolyte membrane 21. At this time, the membrane fouling alarm is triggered and / or the electrolyte membrane 21 is cleaned to restore the ion conductivity of the electrolyte membrane 21, thereby improving the measurement accuracy and extending the service life of the monitoring device.

[0095] As an example, the cleaning agent used in the cleaning procedure is ethylenediaminetetraacetic acid (EDTA).

[0096] Example 1 A monitoring device for anion exchange membrane water electrolysis cell includes: The housing has a cavity for containing the electrolyte and an ion inlet. The ion exchange component includes a 75μm thick ALkymer W-75 anion exchange membrane (ionic conductivity > 0.1S / cm) and a 100μm thick porous titanium support (compressive strength 50MPa, with pores of 10μm diameter running through its thickness and porosity 50%) stacked on both sides of the ALkymer W-75 anion exchange membrane. The ion exchange component is fixed at the ion inlet, and the anion exchange membrane is at an angle of 45° to the horizontal direction. The Hg / HgO reference electrode has an electrode body that is inserted into a receiving cavity and extends into the electrolyte within the receiving cavity. A 316L stainless steel bellows pressure compensator (pressure resistant 50 bar) is installed on the top of the housing.

[0097] An anion exchange membrane water electrolysis system, comprising: An anion exchange membrane water electrolyzer has an electrolyte outlet, an electrolyte inlet and a hydrogen outlet. It is equipped with a Versogen anion exchange membrane and a catalyst. The electrolyte outlet and electrolyte inlet are connected by an electrolyte circulation pipeline. The above-mentioned monitoring device for anion exchange membrane water electrolysis cell; The three-way valve has three ports that are connected to the electrolyte outlet, electrolyte inlet, and ion inlet, respectively. The gas-liquid separator has a gas-liquid inlet and a gas outlet, and the gas-liquid inlet is connected to the hydrogen outlet of the anion exchange membrane water electrolysis cell. The high-pressure system includes a back pressure valve, a first pressure sensor, and a second pressure sensor. The back pressure valve is installed on the gas outlet pipeline of the gas-liquid separator. The first pressure sensor is installed on the electrolyte circulation pipeline of the anion exchange membrane water electrolyzer and is communicatively connected to the back pressure valve and the pressure compensator of the anion exchange membrane water electrolyzer monitoring device. The second pressure sensor is installed on the anion exchange membrane water electrolyzer monitoring device to monitor the pressure inside the receiving cavity of the anion exchange membrane water electrolyzer monitoring device and is communicatively connected to the pressure compensator of the anion exchange membrane water electrolyzer monitoring device.

[0098] The temperature control system, including a thermostatic bath, is installed in the electrolyte circulation pipeline to control the electrolyte temperature in the electrolyte circulation pipeline.

[0099] Test example: The auxiliary terminal of the electrochemical workstation is connected to the working electrode (anode) of the anion exchange membrane water electrolyzer, the counter electrode of the electrochemical workstation is connected to the counter electrode (cathode) of the anion exchange membrane water electrolyzer, and the reference terminal of the electrochemical workstation is connected to the reference electrode to measure the potentials of the working electrode, counter electrode, and reference electrode. The electrolyte temperature of the anion exchange membrane water electrolyzer is controlled at 60°C using a constant temperature bath. The pressure inside the containment chamber is adjusted using a pressure compensator to ensure that the pressure difference between the compensator and the electrolyte outlet is less than 0.3 bar.

[0100] Detection method: (1) Test 1: Long-term stability and life test at atmospheric pressure and 60°C a. Initialization: At normal pressure and 60°C, inject 1M KOH electrolyte into the containment chamber of the anion exchange membrane water electrolysis cell and the anion exchange membrane water electrolysis monitoring device, and start the anion exchange membrane water electrolysis cell with a constant current density (0.5A / cm²).

[0101] b. Reference calibration: At the start of the test (t=0), record a stable initial potential value E0 (the potential of the working electrode relative to the reference electrode).

[0102] c. Continuous monitoring: The electrochemical workstation continuously measures and records the potential of the working electrode relative to the reference electrode (EWE vs. RE). The test runs continuously for more than 2000 hours, and the time-potential curve is continuously recorded. The test results are shown in Table 1.

[0103] (2) Test 2: Test under 30 bar high voltage and high load a. Pressurization: Under the same conditions of 60°C and 1M KOH, the pressure in the anion exchange membrane water electrolysis cell is gradually increased to 30 bar using a high-pressure system.

[0104] b. High load operation: Apply a high current density of 1A / cm² (typical for industrial applications) to simulate full load operation.

[0105] c. Continuous monitoring: The electrochemical workstation continuously measures and records the potential of the working electrode relative to the reference electrode (EWE vs. RE). The test runs continuously for more than 1500 hours, and the time-potential curve is continuously recorded. The test results are shown in Table 1.

[0106] The response time is the time required for the potential to reach its final steady-state value within ±1%.

[0107] Response time calculation method: Determine the final steady-state potential value (e.g., 500mV) after the step from the recorded data.

[0108] Calculate the error band of ±1% (for example, 500mV×1%=5mV, that is, the error band is 495-505mV).

[0109] Starting from the moment the step jump is applied (t0), find the time point (t0) when the potential first enters and remains within this error band. r ).

[0110] Response time = t r -t0.

[0111] Table 1. Performance Test Data

[0112] As can be seen from Table 1: For Test 1, the measured potential value drifted by only ±1mV / h per hour relative to the initial value E0 during the entire 2000h test cycle. This means that the potential fluctuation did not exceed 1mV in any hour, indicating that the anion exchange membrane water electrolysis system is extremely stable.

[0113] For Test 2, after running at 30 bar for more than 1500 hours, the anion exchange membrane did not rupture, significantly deform, or become permanently fouled and blocked, and it could still work normally, which proved the success of the porous titanium support and anti-fouling design. Moreover, the response time and voltage stability did not deteriorate significantly. Therefore, the anion exchange membrane water electrolysis cell monitoring device is feasible for long-term operation.

[0114] The above provides a detailed description of a water electrolysis cell monitoring device, water electrolysis system, and water electrolysis cell monitoring method provided in the embodiments of this application. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A water electrolysis cell monitoring device, characterized in that, For monitoring the potential of a water electrolysis cell (6), the water electrolysis cell (6) having an electrolyte outlet, the water electrolysis cell monitoring device includes: The housing (1) has a cavity (11) for containing electrolyte, and the housing (1) has an ion inlet communicating with the cavity (11), and the ion inlet is configured to be connected to the electrolyte outlet; The ion exchange component (2) includes an electrolyte membrane (21) disposed between the ion inlet and the electrolyte outlet, so that ions in the electrolyte can pass through the electrolyte membrane (21) into the receiving cavity (11); The reference electrode (3) has an electrode body (31) which is inserted into the receiving cavity (11) to extend into the electrolyte.

2. The water electrolysis cell monitoring device according to claim 1, characterized in that, The water electrolysis cell (6) also has an electrolyte inlet (62) and an electrolyte circulation pipeline (61), the electrolyte circulation pipeline (61) connecting the electrolyte outlet (63) and the electrolyte inlet (62); the ion inlet (12) is configured to be connected to the electrolyte circulation pipeline (61) through a three-way valve (7); wherein, the electrolyte membrane (21) is disposed between the three-way valve (7) and the ion inlet (12).

3. The water electrolysis cell monitoring device according to claim 1, characterized in that, The electrolyte membrane is an anion exchange membrane; and / or The electrolyte membrane (21) has a diameter of 5 mm to 10 mm; and / or The thickness of the electrolyte membrane (21) is ≤80μm; and / or The electrolyte membrane (21) has an ionic conductivity > 0.1 S / cm.

4. The water electrolysis cell monitoring device according to claim 1, characterized in that, The surface of the electrolyte membrane (21) is inclined in the horizontal direction.

5. The water electrolysis cell monitoring device according to claim 4, characterized in that, The angle between the surface of the electrolyte membrane (21) and the horizontal direction is 30°-60°.

6. The water electrolysis cell monitoring device according to any one of claims 1-5, characterized in that, The ion exchange component (2) further includes a support (22), which is stacked on at least one side of the electrolyte membrane (21).

7. The water electrolysis cell monitoring device according to claim 6, characterized in that, The support portion (22) has a pore extending through the thickness direction of the electrolyte membrane (21); Wherein, the porosity of the support portion (22) is 40%-60%; and / or The pore size is ≤20μm; and / or The thickness of the support portion (22) is 50μm-150μm; and / or The compressive strength of the support (22) is >50MPa; and / or The material of the support (22) includes one or more of nickel, titanium and stainless steel.

8. The water electrolysis cell monitoring device according to any one of claims 1-7, characterized in that, It also includes a pressure compensator (4), which is disposed in the housing (1) to control the pressure in the receiving cavity (11).

9. A water electrolysis system, characterized in that, include: A water electrolysis cell (6) has an electrolyte outlet (63); The water electrolysis cell monitoring device as described in any one of claims 1-8.

10. The water electrolysis system according to claim 9, characterized in that, It also includes pressure control devices; The pressure control device includes a first pressure sensor (8) and a second pressure sensor (9), which are configured to monitor the pressure on both sides of the electrolyte membrane (21), respectively; and / or The pressure control device includes a back pressure valve (10) configured to control the pressure within the water electrolysis cell (6).

11. The water electrolysis system according to claim 9, characterized in that, It also includes clamping devices disposed on both sides of the ion exchange component (2) facing the ion inlet (12) and facing the electrolyte outlet (63) to fix the ion exchange component (2) between the ion inlet (12) and the electrolyte outlet (63).

12. A method for monitoring a water electrolysis cell, characterized in that, The water electrolysis cell monitoring method, applied in any one of claims 9-11, comprises: Monitor the potential of the anode and / or cathode of the water electrolysis cell (6) relative to the reference electrode (3).

13. The water electrolysis cell monitoring method according to claim 12, characterized in that, Also includes: Measure the conductivity of the electrolyte within the containment cavity (11); When the conductivity is less than or equal to a preset percentage of the initial value of the conductivity, a membrane fouling alarm is triggered and / or the electrolyte membrane is cleaned (21).

14. The water electrolysis cell monitoring method according to claim 13, characterized in that, The preset percentage is 80%.

15. The water electrolysis cell monitoring method according to claim 12, characterized in that, Also includes: Controlling the pressure difference across the electrolyte membrane (21) to be less than or equal to a pressure difference threshold; and / or The electrolyte flow rate at the membrane interface of the electrolyte membrane (21) on the side facing the electrolyte outlet (63) is controlled to be greater than or equal to the flow rate threshold.

16. The water electrolysis cell monitoring method according to claim 15, characterized in that, The differential pressure threshold is 0.3 bar; and / or The flow rate threshold is 0.5 m / s.

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