Cathode and anode conductivity detection device and test method thereof
By introducing conductive components, conductivity testing electrodes and mechanical moving components into the membrane electrode detection device, combining dry and wet testing methods, the problem of difficult to distinguish between cathode and anode conductivity and their variation patterns in the membrane electrode configuration devices in the prior art is solved, and the effect of accurately measuring the conductivity and durability parameters of each part is achieved.
Patent Information
- Application Number
- CN202510156257.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-12
- Publication Date
- 2025-04-29
AI Technical Summary
The prior art is difficult to effectively distinguish the conductivity and variation patterns of the cathode and the anode in membrane electrode configuration devices, and the structure is complex and difficult to apply in practice.
A cathode and anode conductivity detection device is provided, including a conductivity component, a conductivity test electrode and a mechanical moving component. By using a probe or a Hall electrode for dry and wet state testing without introducing an additional reference electrode or detection electrode, the surface resistance and conductivity of the membrane electrode are accurately measured, and the proton conductivity and its variation patterns are extracted.
The electronic conductance, proton conductance and variation patterns of the cathode and anode can be clearly measured, and the data basis is provided for the evaluation of conductivity and durability, providing a basis for the optimization and improvement of the cathode, anode and membrane, avoiding the increase in testing costs caused by the additional structure.
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Figure CN119901969A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of energy conversion, and in particular to a cathode and anode conductivity detection device and a testing method thereof. Background Art
[0002] In recent years, the international community has attached great importance to the development of clean energy technology. Energy conversion technologies such as proton exchange membrane electrolysis for hydrogen production, proton exchange membrane fuel cells, and carbon dioxide electroreduction have developed rapidly. The core of energy conversion technology lies in energy electrochemical devices. In recent years, energy conversion devices with membrane electrode configuration have developed rapidly due to their advantages such as high energy conversion efficiency, adaptability to fluctuating conditions, small footprint, and clean and environmental protection. Devices with membrane electrode configuration are composed of cathode, anode and ion exchange membrane. The conductivity and stability of the cathode and anode have an impact on the overall conductivity and life.
[0003] The membrane electrode configuration is compact, and it is difficult to distinguish how much energy loss comes from the cathode and how much comes from the anode; after long-term operation, it is also difficult to distinguish how much attenuation comes from the cathode and how much attenuation comes from the anode. In addition, the membrane electrode configuration device has both electronic conductivity and ionic conductivity. It is difficult to distinguish how much impedance comes from electronic conductivity and how much impedance comes from ionic conductivity.
[0004] The existing method of distinguishing the conductivity of the anode and cathode is mainly to add a reference electrode or a detection electrode, including placing a platinum wire in the membrane, a gold foil in the anode and cathode, and a reference electrode at the junction of the ion exchange membrane and the electrode. However, the above implementation methods are complex in structure, have additional effects on the structure and conductivity, and are difficult to apply in practice. Summary of the invention
[0005] In order to overcome the problems of complex structure, additional impact on structure and conductivity, and difficulty in practical application of traditional methods, the present invention provides a cathode and anode conductivity detection device and a test method thereof.
[0006] The technical solution adopted by the present invention to achieve the above-mentioned purpose is: In a first aspect, the present invention provides a cathode and anode conductivity detection device, the detection device comprising a conductive component, a conductivity test electrode and a mechanical motion component, the conductive component comprising at least one of a transmission layer, a plate and / or an end plate, an insulating layer is arranged between the conductive component and the conductivity test electrode, and the conductive component is connected to the mechanical motion component.
[0007] Preferably, the conductivity test electrode can be connected to the membrane electrode to be tested.
[0008] Preferably, the mechanical movement assembly comprises a pull rod.
[0009] Preferably, the conductivity testing electrode comprises a probe or a Hall electrode.
[0010] In a second aspect, the present invention provides an application of an anode and cathode conductivity detection device in the test of membrane electrodes for hydrogen production by electrolysis, comprising: pushing a mechanical motion component toward the membrane electrode so that the conductive component contacts the membrane electrode and conducts electricity normally; when testing the resistance and conductivity of the electrode, pulling the mechanical motion component in the opposite direction of the membrane electrode so that the conductive component does not contact the membrane electrode.
[0011] In the third aspect, the present invention provides a testing method for anode and cathode conductivity detection devices, which accurately measures the surface resistance and conductivity of a membrane electrode configuration device through a conductivity test electrode, and then combines dry and wet testing methods to measure the electronic conductivity in the dry state and the total conductivity of electrons and protons in the wet state, thereby extracting the proton conductivity and its changing law.
[0012] Preferably, the dry state test method is to place a conductivity test electrode on one side of the active area of the catalyst layer of the cathode or anode when the membrane electrode is in a dry state, and respectively detect the anode and cathode to obtain the dry state electronic conductivity of both sides.
[0013] Preferably, the wet state test method refers to placing the membrane electrode in a solution or maintaining the membrane electrode at a relatively high humidity; during the test, the membrane electrode is placed in a solution for test or the membrane electrode is taken out of the solution and kept wet for test.
[0014] Preferably, the test method includes a probe test method, a Hall electrode test method and a combination of a probe test method and a Hall electrode test method; the probe test method includes a two-probe test method and a four-probe test method; when using the two-probe test method, the resistance and conductivity are obtained directly by testing the voltage and current; when using the four-probe test method, current is added between two of the probes, and the voltage is measured between the other two probes to obtain the resistance and conductivity; when using the Hall test method, a vertical magnetic field is added, and the Hall voltage and current are detected to obtain the resistance and conductivity.
[0015] Preferably, in addition to measuring proton conductivity, the wet state test method can also form an electrochemical reaction loop because the ionomer begins to conduct protons and act as an electrolyte in the wet state, thereby measuring the conductivity of the tested electrode and the law of conductivity attenuation change. When an AC signal is applied to the conductivity test electrode, the electrochemical impedance is also measured, and the ohmic, charge transfer, and mass transfer impedances are measured, as well as the relaxation time distribution analysis of the electrochemical impedance spectrum.
[0016] Preferably, the solution comprises water, an acid or a base.
[0017] Preferably, the test temperature range is 20° C. to 90° C., and the overall resistance and conductivity at different temperatures are tested.
[0018] The beneficial effects of the present invention are: a cathode and cathode conductivity detection device is developed, which can distinguish the cathode electronic conductivity and its changing law, the anode electronic conductivity and its changing law, the cathode proton conductivity and its changing law, the anode proton conductivity and its changing law; the cathode conductivity and its changing law, the anode conductivity and its changing law; the anode charge transfer impedance and its changing law, the cathode charge transfer impedance and its changing law, through the conductive component, the conductivity test electrode and the mechanical motion component, without introducing an additional reference electrode or detection electrode. In this way, the composition of each part can be clearly determined, providing a data basis for the evaluation of conductivity and durability, and providing a basis for the optimization and improvement of the cathode, anode and membrane. While helping to analyze the conductivity durability parameters of each part, it avoids the introduction of additional structures to increase the testing cost.
[0019] A testing method for anode and cathode conductivity detection devices has been developed. The surface resistance and conductivity of membrane electrode configuration devices can be accurately measured by two-probe testing method, four-probe testing method or Hall testing method. Then, the electronic conductivity is measured in a dry state, and the total conductivity of electrons and protons is measured in a wet state to extract the proton conductivity and its changing law. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 It is a dry electronic conductivity test method; Figure 2 It is the wet total conductivity test method; Figure 3 are the extracted electron and proton conductances before and after the run; Figure 4 It is a schematic diagram of the structure of a cathode and anode conductivity detection device. DETAILED DESCRIPTION
[0021] like Figure 1 As shown, a cathode and anode conductivity detection device, based on a traditional electrolytic cell, connects the components outside the membrane electrode such as the transmission layer, the electrode plate and the end plate of the electrode to be tested, and then connects a mechanical motion component, wherein the mechanical motion component includes a pull rod. Then an insulating layer is arranged between the conductive component and the conductivity test electrode, and a probe or Hall electrode is placed outside the insulating layer. When it is not necessary to test the conductivity of the object to be tested, the pull rod is pushed toward the membrane electrode so that the transmission layer, the electrode plate and the end plate are in contact with the membrane electrode and conduct electricity normally. When it is necessary to test the conductivity of the object to be tested, the pull rod is pulled out of the electrolytic cell so that the transmission layer, the electrode plate and the end plate are not in contact with the membrane electrode, and then the conductivity is tested by a probe or a Hall electrode. The testable contents include the dry electronic conductivity, wet conductivity, conductivity, AC impedance, etc. mentioned below.
[0022] The test method of dry state electronic conductivity is as follows Figure 2As shown, when the membrane electrode is in a dry state, a probe or Hall method is used and placed on one side of the active area of the catalyst layer of the cathode or anode. When two probes are used, the resistance and conductivity are obtained directly by testing the voltage and current; when four probes are used, a current is added between two probes, and the voltage is measured between the other two probes to obtain the resistance and conductivity. When the Hall test method is used, a vertical magnetic field is added, and the Hall voltage and current are detected to obtain the resistance and conductivity. One or more of the probe method and the Hall method can be used. The dry electronic conductivity of both sides can be obtained by detecting the anode and cathode separately.
[0023] The test method for wet total conductivity is as follows: Figure 3 As shown, wet state means that the membrane electrode is placed in a solution or maintained at a high humidity (water content ≥ 20%). The solution can be water, acid or alkali. During the test, the membrane electrode can be placed in the solution for testing, or the membrane electrode can be taken out of the solution and tested while being wet. During the test, the temperature can be changed (the solution must remain in liquid state) to test the overall resistance and conductivity at different temperatures. In a wet environment, electrons and protons conduct electricity at the same time, and the total resistance and conductivity are measured. The proton conductivity is obtained by subtracting the electron conductivity from the total conductivity.
[0024] Example 1: The electron conductivities of the cathode and anode of the membrane electrode that was assembled but not operated were 4.984 S / cm and 3.347 S / cm respectively by the two-probe test method. Figure 4 After 100 hours, the electron conductivities of the cathode and anode were 4.048 and 1.845 S / cm respectively. Figure 4 As shown. The two-probe test method was used to extract the proton conductivities of the cathode and anode of the membrane electrode that had been assembled but not operated, and the results were 0.365 S / cm and 3.194 S / cm, respectively. Figure 4 After 100 hours, the proton conductivities of the extracted cathode and anode were 0.372 S / cm and 3.341 S / cm, respectively. Figure 4 shown.
[0025] Example 2: The electron conductances of the cathode and anode of the unused membrane electrode tested in the example by the four-probe test method were 5.081S / cm and 3.773S / cm, respectively. After running for 200 hours, the electron conductances of the cathode and anode were tested again, and they were 4.145 and 2.058 S / cm, respectively. The proton conductances of the cathode and anode of the unused membrane electrode extracted and tested in the example by the four-probe test method were 0.581S / cm and 3.325S / cm, respectively. After 100 hours, the extracted proton conductances of the cathode and anode were tested again, and they were 0.415 S / cm and 3.042S / cm, respectively.
[0026] The electron conductance of the cathode and anode of the membrane electrode that was assembled once but not operated was tested in the example by the Hall electrode test method, and the electron conductances of the cathode and anode were 5.115S / cm and 3.780S / cm, respectively. After 1000h, the electron conductances of the cathode and anode were tested again, and the electron conductances of the cathode and anode were 4.249 and 1.733 S / cm, respectively. The proton conductances of the cathode and anode of the membrane electrode that was assembled once but not operated were extracted and tested in the example by the Hall electrode test method, and the proton conductances of the cathode and anode were 0.585 S / cm and 3.329S / cm, respectively. After 1000h, the extracted proton conductances of the cathode and anode were 0.335 S / cm and 3.149S / cm, respectively.
[0027] The invention discloses an anode and cathode conductivity detection device and a test method thereof, comprising a conductive component, a conductivity test electrode and a mechanical motion component; the invention has the beneficial effect that, without introducing an additional reference electrode or a detection electrode, the following can be distinguished: cathode electronic conductivity and its variation law, anode electronic conductivity and its variation law, cathode proton conductivity and its variation law, anode proton conductivity and its variation law; cathode conductivity and its variation law, anode conductivity and its variation law, anode charge transfer impedance and its variation law, cathode charge transfer impedance and its variation law, so as to clearly determine the composition of each part, provide a data basis for the evaluation of conductivity and durability, provide a basis for the optimization and improvement of the cathode, anode and membrane, and avoid the increase of the test cost caused by the introduction of additional structures while helping to analyze the conductivity durability parameters of each part.
Claims
1. A cathode and anode conductivity detection device, characterized in that: It includes a conductive component, a conductivity test electrode and a mechanical motion component. The conductive component includes at least one of a transmission layer, a plate and / or an end plate. An insulating layer is arranged between the conductive component and the conductivity test electrode. The conductive component is connected to the mechanical motion component.
2. A cathode and anode conductivity detection device according to claim 1, characterized in that: The conductivity test electrode can be connected to the membrane electrode to be tested.
3. The device for detecting the conductivity of cathode and anode according to claim 1, characterized in that: The mechanical movement assembly includes a draw rod.
4. The device for detecting the conductivity of cathode and anode according to claim 1, characterized in that: The conductivity testing electrode includes a probe or a Hall electrode.
5. An application of the anode and cathode conductivity detection device as claimed in any one of claims 1 to 4 in the test of hydrogen production membrane electrodes by electrolysis, characterized in that: include: Push the mechanical moving component toward the membrane electrode so that the conductive component contacts the membrane electrode and conducts electricity normally; When testing the resistance and conductivity of the electrode, the mechanical moving component is pulled in the opposite direction of the membrane electrode so that the conductive component does not contact the membrane electrode.
6. A method for testing a cathode and anode conductivity detection device, characterized in that: The surface resistance and conductivity of the membrane electrode configuration device are accurately measured by the conductivity test electrode, and then the dry and wet test methods are combined to measure the electronic conductivity in the dry state and the total conductivity of electrons and protons in the wet state, and the proton conductivity and its change law are extracted.
7. The method for testing the anode and cathode conductivity detection device according to claim 6, characterized in that: The dry state test method is to place a conductivity test electrode on one side of the active area of the catalyst layer of the cathode or anode when the membrane electrode is in a dry state, and detect the dry state electronic conductivity of the anode and / or cathode.
8. The method for testing the anode and cathode conductivity detection device according to claim 6, characterized in that: The wet state test method refers to placing the membrane electrode in a solution or maintaining a high humidity of the membrane electrode; during the test, the membrane electrode is placed in a solution for test or the membrane electrode is taken out of the solution and kept wet for test, and is placed on one side of the active area of the catalyst layer of the cathode or anode, and the wet total conductivity of the anode and / or cathode is detected.
9. The method for testing the anode and cathode conductivity detection device according to claim 6, characterized in that: The test method includes a probe test method, a Hall electrode test method and a combination of a probe test method and a Hall electrode test method; the probe test method includes a two-probe test method and a four-probe test method; when the two-probe test method is used, the resistance and conductivity are directly obtained by testing the voltage and current; when the four-probe test method is used, current is added between two probes, and the voltage is measured between the other two probes to obtain the resistance and conductivity; when the Hall test method is used, a vertical magnetic field is added, and the Hall voltage and current are detected to obtain the resistance and conductivity.
10. The method for testing the anode and cathode conductivity detection device according to claim 6, characterized in that: In addition to measuring proton conductivity, the wet state test method can also form an electrochemical reaction loop because the ionomer begins to conduct protons and act as an electrolyte in the wet state, thereby measuring the conductivity of the tested electrode and the law of conductivity attenuation change. When an AC signal is applied to the conductivity test electrode, the electrochemical impedance is also measured, and the ohmic, charge transfer, and mass transfer impedances are measured, as well as the relaxation time distribution analysis of the electrochemical impedance spectrum.
11. The method for testing the anode and cathode conductivity detection device according to claim 8, characterized in that: The solution includes water, an acid or a base.
12. The method for testing the anode and cathode conductivity detection device according to claim 8, characterized in that: The test temperature range is from 20℃ to 90℃, and the overall resistance and conductivity at different temperatures are tested.