Method for testing conductivity of anion exchange membrane

Abstract

According to the method for testing the conductivity of the anion-exchange membrane, before the electrochemical impedance test is carried out on the anion-exchange membrane, the anion-exchange membrane is completely immersed in the water, then the electrochemical impedance test is carried out, and in the test process, the anion-exchange membrane is located in the water all the time, so that the anion-exchange membrane is not in contact with the air, and the conductivity of the anion-exchange membrane is not influenced. Furthermore, the reaction between hydroxyl ions on the anion exchange membrane and carbon dioxide in the air is reduced, the carbonation problem of the anion exchange membrane in the testing process is effectively solved, and the accuracy of the conductivity test of the anion exchange membrane is improved.

Description

Technical Field

[0001] The present application relates to the technical field of anion exchange membrane conductivity testing, and in particular to a method for testing the conductivity of anion exchange membrane. Background Art

[0002] In the related technology, the conductivity test method of the hydrogen-oxygen anion exchange membrane mainly refers to GB / T20042.3-2022 "Proton Exchange Membrane Fuel Cell Part 3: Proton Exchange Membrane Test Method". During the test, the hydrogen-oxygen anion exchange membrane is directly placed in a constant temperature and humidity environment for power-on testing. Under the action of the electric field, the hydroxide ions in the anion exchange membrane will migrate to form a current. By measuring the voltage and current at both ends of the anion exchange membrane, the resistance of the anion exchange membrane is calculated, and then the conductivity of the anion exchange membrane is calculated using the formula.

[0003] However, during the test of the anion exchange membrane, the hydroxide ions on the anion exchange membrane easily react with the carbon dioxide in the air to generate bicarbonate ions and / or carbonate ions, which replace the hydroxide ions and adsorb on the positively charged active groups of the anion exchange membrane, causing the anion exchange membrane to be carbonated. The carbonation of the anion exchange membrane causes the anion groups on the anion exchange membrane to change, affecting the anion exchange membrane's ability to conduct anions. Therefore, conducting conductivity tests on anion exchange membranes directly in the air is likely to cause distorted results. Summary of the invention

[0004] The embodiments of the present application provide a method for testing the electrical conductivity of an anion exchange membrane, which can improve the technical problem that during the testing process of the anion exchange membrane, the hydroxide ions on the anion exchange membrane easily react with carbon dioxide in the air to generate bicarbonate ions and / or carbonate ions, causing carbonation of the anion exchange membrane and resulting in distortion of the conductivity test results of the anion exchange membrane.

[0005] The embodiment of the present application provides a method for testing the conductivity of an anion exchange membrane, comprising the following steps:

[0006] providing an anion exchange membrane having hydroxide ions;

[0007] Completely immersing the anion exchange membrane in water;

[0008] An electrochemical impedance test is performed on the anion exchange membrane completely immersed in the water to obtain the resistance of the anion exchange membrane, so as to calculate the conductivity of the anion exchange membrane through the resistance.

[0009] In one embodiment, the testing method specifically comprises the following steps:

[0010] providing the anion exchange membrane;

[0011] The anion exchange membrane is completely immersed in water and the water is electrolyzed to obtain an activated anion exchange membrane;

[0012] An electrochemical impedance test is performed on the activated anion exchange membrane completely immersed in the water to obtain the resistance of the anion exchange membrane, so as to calculate the conductivity of the anion exchange membrane through the resistance.

[0013] In one embodiment, the step of completely immersing the anion exchange membrane in water and electrolyzing the water specifically comprises:

[0014] Fixing the anion exchange membrane between the first electrode and the second electrode of the fixture so that the anion exchange membrane contacts the first electrode and the second electrode to obtain a sample device to be tested;

[0015] Placing the sample device to be tested in the water so that the water completely immerses the anion exchange membrane in the sample device to be tested;

[0016] A power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water to obtain the activated anion exchange membrane.

[0017] In one embodiment, the activation process is a constant voltage activation process;

[0018] The power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water, specifically comprising:

[0019] The positive electrode and the negative electrode of the power supply device are electrically connected to the first electrode and the second electrode respectively, and the power supply device applies a constant voltage to the water;

[0020] A current curve showing the change of current with time during the activation process is obtained, and when the slope of the current curve is less than 0.1, it is judged that the activation is complete.

[0021] In one embodiment, the activation process is a constant current activation process;

[0022] The power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water, specifically comprising:

[0023] The positive electrode and the negative electrode of the power supply device are electrically connected to the first electrode and the second electrode respectively, and the power supply device applies a constant current to the water;

[0024] A voltage curve showing the voltage changing with time during the activation process is obtained, and when the slope of the voltage curve is less than 0.1, it is determined that the activation is complete.

[0025] In one embodiment, the activation treatment is a constant voltage activation treatment, the voltage of the constant voltage activation treatment is 3V-10V, and the time of the constant voltage activation treatment is 6h-30h.

[0026] In one embodiment, the protection current of the constant voltage activation process is 0.5A-1.0A.

[0027] In one embodiment, the activation treatment is a constant current activation treatment, the current of the constant current activation treatment is 400 μA-2000 μA, and the time of the constant current activation treatment is 15h-40h.

[0028] In one embodiment, the protection voltage of the constant current activation process is 8V-10V.

[0029] In one embodiment, the steps of the electrochemical impedance test specifically include:

[0030] An electrochemical workstation is electrically connected to the first electrode and the second electrode, and the resistance is measured by the electrochemical workstation.

[0031] In one embodiment, the conditions of the electrochemical impedance test are: the test temperature is 75° C.-85° C., and / or the disturbance voltage is 0.1 mV-10 mV, and / or the test frequency is 0.1 MHz-5 MHz.

[0032] In one embodiment, the conductivity is calculated as follows: σ=L / a*b*R;

[0033] Where, σ is the conductivity, in mS / cm;

[0034] L is the distance between the first electrode and the second electrode, in cm;

[0035] a is the width of the anion exchange membrane, in cm;

[0036] b is the thickness of the anion exchange membrane, in cm;

[0037] R is the resistance, in Ω.

[0038] Beneficial effects of the embodiments of the present application:

[0039] In the present application, before performing an electrochemical impedance test on the anion exchange membrane, the anion exchange membrane is first completely immersed in water, and then the electrochemical impedance test is performed. During the test, the anion exchange membrane is always located in water, so that the anion exchange membrane is not in contact with the air, thereby reducing the reaction between the hydroxide ions on the anion exchange membrane and the carbon dioxide in the air, effectively improving the carbonation problem of the anion exchange membrane during the test, and improving the accuracy of the anion exchange membrane conductivity test. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the solutions in the present application or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0041] Figure 1 This is a current curve diagram showing the change of current over time during the activation process of Example 1 of the present application;

[0042] Figure 2 This is a voltage curve diagram showing the voltage changing with time during the activation process of Example 6 of the present application. DETAILED DESCRIPTION

[0043] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the directional words such as "upper" and "lower" used generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inside" and "outside" refer to the outline of the device.

[0044] In the related art, the hydroxide on the anion exchange membrane easily reacts with the carbon dioxide in the air to generate bicarbonate ions and / or carbonate ions, causing carbonation of the anion exchange membrane and resulting in distortion of the conductivity test results of the anion exchange membrane, which needs to be further improved.

[0045] To solve the above problems, the present invention provides a method for testing an anion exchange membrane, comprising the following steps:

[0046] S1. providing an anion exchange membrane, wherein the anion exchange membrane has hydroxide ions;

[0047] S2, completely immersing the anion exchange membrane in water;

[0048] S3. Performing an electrochemical impedance test on the anion exchange membrane completely immersed in water to obtain the resistance of the anion exchange membrane, and calculating the conductivity of the anion exchange membrane through the resistance.

[0049] In this embodiment, before performing an electrochemical impedance test on the anion exchange membrane, the anion exchange membrane is first completely immersed in water, and then the electrochemical impedance test is performed. During the test, the anion exchange membrane is always located in water, so that the anion exchange membrane is not in contact with the air, thereby reducing the reaction between the hydroxide ions on the anion exchange membrane and the carbon dioxide in the air, effectively improving the carbonation problem of the anion exchange membrane during the test, and improving the accuracy of the anion exchange membrane conductivity test.

[0050] In this embodiment, the anion exchange membrane is an anion exchange membrane having hydroxide ions, and the type of the anion exchange membrane is not limited. For example, the anion exchange membrane can be one of a quaternary ammonium ion exchange membrane, an imidazole salt ion exchange membrane, a guanidine salt ion exchange membrane, etc., which is not limited here.

[0051] In one embodiment, the method for testing an anion exchange membrane specifically comprises the following steps:

[0052] S11, providing the anion exchange membrane;

[0053] S12, completely immersing the anion exchange membrane in water and electrolyzing the water to obtain an activated anion exchange membrane;

[0054] S13, performing an electrochemical impedance test on the activated anion exchange membrane completely immersed in the water to obtain the resistance of the anion exchange membrane, and calculating the conductivity of the anion exchange membrane through the resistance.

[0055] In this embodiment, before the test, since the anion exchange membrane is easily exposed to air during storage, transportation, etc., the anion exchange membrane has been carbonated before the test, and at least part of the hydroxide ions on the anion exchange membrane react with carbon dioxide in the air to generate carbonate ions and / or bicarbonate ions, affecting the accuracy of the anion exchange membrane conductivity test. Before the electrochemical impedance test of the anion exchange membrane, the carbonated anion exchange membrane is completely immersed in water and electrolyzed; on the one hand, the carbonate ions and / or bicarbonate ions on the anion exchange membrane can undergo a hydrolysis reaction in water to generate CO2 and OH -On the other hand, when water is electrolyzed, water molecules can be ionized into hydrogen ions and hydroxide ions. On the cathode side, the hydrogen ions generated by water ionization can gain electrons to undergo a reduction reaction to generate hydrogen. On the anode side, the hydroxide ions generated by water ionization can lose electrons to undergo an oxidation reaction to generate oxygen and water. As the oxidation reaction proceeds, the OH - As the concentration of carbonate ions decreases, the hydrolysis equilibrium of carbonate ions and / or bicarbonate ions moves toward the anode side, and more and more carbonate ions and / or bicarbonate ions can leave the positively charged active groups of the anion exchange membrane and hydrolyze to generate CO2 and OH on the anode side. - CO2 is eventually discharged as gas, while carbonate ions and / or bicarbonate ions are hydrolyzed at the anode side to generate OH - It can replace carbonate ions and / or bicarbonate ions and combine with the positively charged active groups of the anion exchange membrane to obtain an activated anion exchange membrane; the activation treatment can convert carbonate ions and / or bicarbonate ions back into hydroxide ions, reducing the effect of carbonation on the conductivity of the anion exchange membrane; in addition, after the activation treatment, the electrochemical impedance test is directly performed on the activated anion exchange membrane immersed in water, which can prevent the anion exchange membrane from contacting with air during the test, thereby improving the carbonation of the anion exchange membrane and further improving the accuracy of the anion exchange membrane conductivity test.

[0056] In one embodiment, step S12 specifically includes:

[0057] S121, fixing the anion exchange membrane between the first electrode and the second electrode of the fixture so that the anion exchange membrane is in contact with the first electrode and the second electrode, thereby obtaining a sample device to be tested;

[0058] S122, placing the sample device to be tested in water, so that the water completely immerses the anion exchange membrane in the sample device to be tested;

[0059] S123, electrically connecting the power supply device to the first electrode and the second electrode, and allowing the power supply device to apply voltage or current to the water to electrolyze the water to obtain an anion exchange membrane after activation treatment.

[0060] In this embodiment, on the one hand, the anion exchange membrane is fixed in a fixture, and the fixture can fix and support the anion exchange membrane. At the same time, the first electrode and the second electrode of the fixture are electrically connected to the anion exchange membrane and the power supply device, respectively. After the sample device to be tested is placed in water, the power supply device, the first electrode, the second electrode, the anion exchange membrane and the water form a current loop, and the current of the power supply device can be transmitted to the anion exchange membrane and the water through the first electrode and the second electrode. On the other hand, the carbonated anion exchange membrane in the sample device to be tested is completely immersed in water, so that the carbonate ions and bicarbonate ions on the entire anion exchange membrane can be converted back to hydroxide ions. At the same time, the contact between the anion exchange membrane and the air can be reduced, thereby reducing the generation of new carbonate ions and bicarbonate ions by the anion exchange membrane during the activation process.

[0061] In this embodiment, the applied voltage may be a constant voltage or a variable voltage, which is not limited here; the applied current may be a constant current or a variable current, which is not limited here.

[0062] In one embodiment, the activation process is a constant voltage activation process, and step S123 specifically includes:

[0063] S1231, electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, and making the power supply device apply a constant voltage to the water;

[0064] S1232. Obtain a current curve showing the change of current over time during the activation process. If the slope of the current curve is less than 0.1, it is determined that the activation is complete.

[0065] In this embodiment, on the one hand, the power supply device applies a constant voltage to the water, which can ensure the stability of the driving voltage during the activation process and facilitate accurate control and regulation of the activation process; on the other hand, since the water and the anion exchange membrane constitute part of the current loop, the type and content of anions on the water and the anion exchange membrane will affect the resistance of the current loop, and further affect the current of the current loop. During the activation process, the HCO3 on the anion exchange membrane - 、CO3 2- During the electrolysis of water, plasma gradually turns into OH - , the types and contents of anions in water and on the anion exchange membrane are constantly changing, so the resistance of the current loop will change. When the voltage is constant, the current in the current loop will change with the change of resistance. Therefore, before the activation is completed, the magnitude of the current in the current loop will change, and the slope of the current curve is large; when the activation is completed, the HCO3 in water and on the anion exchange membrane - 、CO3 2- The anions are completely converted into OH -, the types and contents of anions in water and on the anion exchange membrane remain basically unchanged, the resistance in the current loop and the magnitude of the current in the current loop are basically stable, and the slope of the current curve is less than 0.1. Therefore, during the activation process, the current curve of the current changing with time is obtained, and the activation is judged to be complete according to the slope of the current curve, which can further ensure the effect of the activation.

[0066] In one embodiment, the voltage of the constant voltage activation treatment is 3V-10V, and the time of the constant voltage activation treatment is 6h-30h. Optionally, the voltage of the constant voltage activation treatment can be any one of 3V, 4V, 5V, 6V, 7V, 8V, 9V, 10V, etc., or a range between any two of them; the time of the constant voltage activation treatment can be any one of 6h, 10h, 14h, 18h, 20h, 24h, 26h, 28h, 30h, etc., or a range between any two of them. In this embodiment, if the voltage value is too small, it is easy to cause HCO3 - 、CO3 2- Plasma conversion to OH - The effect is not ideal; if the voltage value is too large, it is easy to cause physical damage such as rupture and perforation of the anion exchange membrane and change the functional groups on the anion exchange membrane, thereby affecting the conductivity of the anion exchange membrane.

[0067] In one embodiment, the protection current of the constant voltage activation treatment is 0.5A-1A. In this embodiment, under constant voltage, if the current passing through the anion exchange membrane is too large, it is easy to cause the anion exchange membrane to be subjected to excessive electrochemical stress and damage the structure of the anion exchange membrane. Setting the protection current can limit the size of the current passing through the anion exchange membrane and reduce the damage of the anion exchange membrane due to excessive current during the activation process.

[0068] In one embodiment, the activation process is a constant current activation process, and step S23 specifically includes:

[0069] S233, electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, and making the power supply device apply a constant current to the carbonation anion exchange membrane in the water;

[0070] S234, obtaining a voltage curve showing the voltage changing with time during the activation process, and determining that the activation is complete when the slope of the voltage curve is less than 0.1.

[0071] In this embodiment, on the one hand, the power supply device applies a constant current to the carbonated anion exchange membrane in the water. Applying a constant current can ensure the stability of the current and ionization rate during the activation process, and facilitate accurate control and regulation of the activation process. On the other hand, since the water and the anion exchange membrane constitute part of the current loop, the type and content of anions on the water and the anion exchange membrane will affect the resistance of the current loop, and further affect the voltage of the current loop. During the activation process, the HCO3 on the anion exchange membrane - 、CO3 2- During the electrolysis of water, plasma gradually turns into OH - , the types and contents of anions in water and on the anion exchange membrane are constantly changing, so the resistance of the current loop will change. When the current is constant, the voltage in the current loop will change with the change of resistance. Therefore, before the activation is completed, the voltage in the current loop will change, and the slope of the voltage curve is large; when the activation is completed, the HCO3 in water and on the anion exchange membrane - 、CO3 2- The anions are completely converted into OH - , the types and contents of anions in water and on the anion exchange membrane remain basically unchanged, the resistance in the current loop and the voltage in the current loop are basically stable, and the slope of the voltage curve is less than 0.1. Therefore, during the activation process, the voltage curve of the voltage changing with time is obtained, and the activation is judged to be complete according to the slope of the voltage curve, which can further ensure the effect of the activation.

[0072] In one embodiment, the activation treatment is a constant current activation treatment, the current of the constant current activation treatment is 400μA-2000μA, and the time of the constant current activation treatment is 15h-40h. Optionally, the current of the constant current activation treatment can be any one of 400μA, 800μA, 1000μA, 1200μA, 1500μA, 1800μA, 2000μA, etc., or a range between any two; the time of the constant current activation treatment can be any one of 15h, 20h, 25h, 30h, 35h, 40h, etc., or a range between any two. In this embodiment, if the value of the constant current is too small, it is easy to cause HCO3 - 、CO3 2- Plasma conversion to OH - The effect is not ideal; if the value of the constant current is too large, it is easy to cause physical damage such as rupture and perforation of the anion exchange membrane and change the functional groups on the anion exchange membrane, thereby affecting the conductivity of the anion exchange membrane.

[0073] In one embodiment, the protection voltage of the constant current activation treatment is 8V-10V. In this embodiment, under constant current, if the voltage passing through the anion exchange membrane is too large, it is easy to cause the anion exchange membrane to be subjected to excessive electrochemical stress and damage the structure of the anion exchange membrane. Setting the protection voltage can limit the magnitude of the voltage passing through the anion exchange membrane and prevent the anion exchange membrane from being damaged by excessive voltage during the activation process.

[0074] In one embodiment, the steps of electrochemical impedance spectroscopy specifically include:

[0075] An electrochemical workstation is electrically connected to the first electrode and the second electrode, and the resistance of the anion exchange membrane after the activation treatment is measured by the electrochemical workstation.

[0076] In one embodiment, the conditions of the electrochemical impedance test are: the test temperature is 75°C-85°C, and / or the disturbance voltage is 0.1mV-10mV, and / or the test frequency is 0.1MHz-5MHz. Optionally, the test temperature can be any one of 75°C, 78°C, 80°C, 83°C, 85°C, etc. or a range between any two; the disturbance voltage can be any one of 0.1mV, 2mV, 4mV, 6mV, 8mV, 10mV, etc. or a range between any two; the test frequency can be any one of 0.1MHz, 2MHz, 3MHz, 4MHz, 5MHz, etc. or a range between any two.

[0077] In one embodiment, the calculation formula of conductivity is: σ=L / a*b*R; wherein σ is conductivity, and the unit is mS / cm; L is the distance between the first electrode and the second electrode, and the unit is cm; a is the width of the anion exchange membrane, and the unit is cm; b is the thickness of the anion exchange membrane, and the unit is cm; R is the resistance, and the unit is Ω.

[0078] The above scheme is further described below in conjunction with specific implementation examples. The preferred embodiments of the present application are described in detail as follows:

[0079] Product Example 1

[0080] 15g of p-terphenyl and 1g of N-methyl-4-piperidone were polymerized in a reaction device to form an intermediate, and then the intermediate was reacted with a quaternary ammonium agent to prepare an anion exchange resin, and the anion exchange resin was cast into an anion exchange membrane in a membrane forming device, and then the anion exchange membrane was immersed in a 60°C 1M KOH solution for 24 hours to convert anions on the anion exchange membrane into OH － , a hydroxide-type anion exchange membrane immersed in a KOH solution was obtained, wherein the hydroxide-type anion exchange membrane had a thickness of 100 μm, a length of 45 cm, and a width of 10 cm.

[0081] Reference example 1

[0082] This reference example provides a method for testing the conductivity of an anion exchange membrane, comprising the following steps:

[0083] 1. Place the hydroxide anion exchange membrane immersed in KOH solution prepared in Product Example 1 in a glove box filled with N2, take out the hydroxide anion exchange membrane from the KOH solution in the glove box environment filled with N2 and wash it with pure water, fix the washed hydroxide anion exchange membrane in a fixture, so that the first electrode and the second electrode of the fixture are in close contact with the hydroxide anion exchange membrane, and the distance between the first electrode and the second electrode is 1 cm;

[0084] 2. Place the fixture with the hydrogen-oxygen anion exchange membrane fixed in a water tank in a glove box filled with N2, so that the water in the water tank completely immerses the hydrogen-oxygen anion exchange membrane;

[0085] 3. Take the water tank out of the glove box and place it in a water bath for constant temperature heating. After the temperature of the water in the water tank stabilizes to 80°C, electrically connect the first electrode and the second electrode to the electrochemical workstation, select the EIS program, the perturbation voltage is 1mV, the test frequency is 1MHZ, read the resistance of the anion exchange membrane, and calculate the conductivity of the hydroxyl anion exchange membrane to be 139mS / cm using the formula σ=L / a*b*R.

[0086] In Reference Example 1, the oxyhydroxide anion exchange membrane is basically not in contact with the air from the completion of preparation to the end of the conductivity test, and the influence of carbonation on the conductivity of the oxyhydroxide anion exchange membrane can be eliminated. The conductivity value measured in Reference Example 1 can be used as a standard reference value. The measured values ​​of the remaining embodiments and comparative examples are compared with the standard reference value. The closer they are to the standard reference value, the more accurate the testing method is.

[0087] Example 1

[0088] This embodiment provides a method for testing the conductivity of an anion exchange membrane, comprising the following steps:

[0089] 1. Provide the hydroxide type anion exchange membrane immersed in KOH solution prepared in product example 1;

[0090] 2. Take out the hydroxide anion exchange membrane from the KOH solution and wash it with pure water. Expose the washed hydroxide anion exchange membrane to air at 25°C for 48 hours to obtain a carbonated anion exchange membrane.

[0091] 3. Fix the carbonated anion exchange membrane in a fixture so that the first electrode and the second electrode of the fixture are in close contact with the carbonated anion exchange membrane, and the distance between the first electrode and the second electrode is 1 cm.

[0092] 4. Place the fixture with the carbonated anion exchange membrane fixed in the water tank so that the water in the water tank completely immerses the carbonated anion exchange membrane;

[0093] 5. The positive and negative electrodes of the power supply device are electrically connected to the first electrode and the second electrode respectively, the constant voltage mode is selected, the voltage is set to 5V, the protection current is set to 1A, the activation time is 8h, and the activation is started and the current curve of the current generated during the electrolysis of water is obtained as a function of time. Figure 1 After activation, the slope of the current curve recorded after 7.5h was less than 0.1.

[0094] 6. Remove the power supply device, place the water tank in a water bath and heat it at a constant temperature. After the temperature of the water in the water tank stabilizes to 80°C, electrically connect the first electrode and the second electrode to the electrochemical workstation, select the EIS program, set the perturbation voltage to 1mV, and the test frequency to 1MHZ. Read the resistance of the anion exchange membrane and calculate the conductivity of the hydroxyl anion exchange membrane using the formula σ=L / a*b*R.

[0095] Example 2

[0096] The difference between Example 2 and Example 1 is that:

[0097] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant voltage mode, setting the voltage to 10V, setting the protection current to 1A, and setting the activation time to 6h, starting the activation and obtaining the current curve of the current generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the current curve between 5.5h and 6h is less than 0.1;

[0098] The rest is the same as in Example 1.

[0099] Example 3

[0100] The difference between Example 3 and Example 1 is that:

[0101] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant voltage mode, setting the voltage to 3V, setting the protection current to 1A, and setting the activation time to 30h, starting the activation and obtaining the current curve of the current generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the current curve between 29.5h and 30h is less than 0.1;

[0102] The rest is the same as in Example 1.

[0103] Example 4

[0104] The difference between Example 4 and Example 1 is that:

[0105] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant voltage mode, setting the voltage to 13V, setting the protection current to 1A, and setting the activation time to 6h, starting the activation and obtaining the current curve of the current generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the current curve between 5.5h and 6h is less than 0.1;

[0106] The rest is the same as in Example 1.

[0107] Example 5

[0108] The difference between Example 5 and Example 1 is that:

[0109] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant voltage mode, setting the voltage to 1.5V, setting the protection current to 1A, and setting the activation time to 30h, starting the activation and obtaining the current curve of the current generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the current curve between 29.5h and 30h is greater than 0.1;

[0110] The rest is the same as in Example 1.

[0111] Example 6

[0112] The difference between Example 6 and Example 1 is that:

[0113] Step 5 is: electrically connect the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, select the constant current mode, set the current to 400μA, set the protection voltage to 10V, and the activation time to 40h, start activation and obtain the voltage curve of the voltage generated during water electrolysis over time, see Figure 2 , after the activation, the slope of the voltage curve recorded after 24h was less than 0.1;

[0114] The rest is the same as in Example 1.

[0115] Example 7

[0116] The difference between Example 7 and Example 6 is that:

[0117] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant current mode, setting the current to 2000 μA, setting the protection voltage to 10 V, and setting the activation time to 15 h, starting the activation and obtaining a voltage curve of the voltage generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the voltage curve between the 14.5 h and the 15 h is less than 0.1;

[0118] The rest is the same as Example 6.

[0119] Example 8

[0120] The difference between Example 8 and Example 6 is that:

[0121] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant current mode, setting the current to 3000 μA, setting the protection voltage to 10 V, and setting the activation time to 15 h, starting the activation and obtaining a voltage curve of the voltage generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the voltage curve between the 14.5 h and the 15 h is less than 0.1;

[0122] The rest is the same as Example 6.

[0123] Example 9

[0124] The difference between Example 9 and Example 6 is that:

[0125] Step 5 is: electrically connecting the positive electrode and the negative electrode of the power supply device to the first electrode and the second electrode respectively, selecting the constant current mode, setting the current to 200 μA, setting the protection voltage to 10 V, and setting the activation time to 40 h, starting the activation and obtaining a voltage curve of the voltage generated during the electrolysis of water over time, and after the activation is completed, recording that the slope of the voltage curve between the 39.5 h and the 40 h is greater than 0.1;

[0126] The rest is the same as Example 6.

[0127] Example 10

[0128] This embodiment provides a method for testing the conductivity of an anion exchange membrane, comprising the following steps:

[0129] 1. Provide the hydroxide type anion exchange membrane immersed in KOH solution prepared in product example 1;

[0130] 2. Take out the hydroxide-type anion exchange membrane from the KOH solution and completely immerse the hydroxide-type anion exchange membrane in the water in the water tank. Use a clamp to clamp the hydroxide-type anion exchange membrane in the water so that the first electrode and the second electrode of the clamp are in close contact with the carbonated anion exchange membrane, and the distance between the first electrode and the second electrode is 1 cm.

[0131] 3. Place the water tank containing the hydroxyl anion exchange membrane in a water bath and heat it at a constant temperature. After the temperature of the water in the water tank stabilizes to 80°C, electrically connect the first electrode and the second electrode to the electrochemical workstation, select the EIS program, the perturbation voltage is 1mV, the test frequency is 1MHZ, read the resistance of the anion exchange membrane, and calculate the conductivity of the hydroxyl anion exchange membrane using the formula σ=L / a*b*R.

[0132] Embodiment 11

[0133] The difference between Example 11 and Example 1 is that:

[0134] Step 4 is: placing the fixture with the carbonated anion exchange membrane fixed thereon in a water tank, so that a portion of the carbonated anion exchange membrane is immersed in water;

[0135] The rest is the same as in Example 1.

[0136] Example 12 (Comparative Example 3)

[0137] The difference between Example 12 and Example 6 is that:

[0138] Step 4 is: placing the fixture with the carbonated anion exchange membrane fixed thereon in a water tank, so that a portion of the carbonated anion exchange membrane is immersed in water;

[0139] The rest is the same as Example 6.

[0140] Comparative Example 1

[0141] The difference between Comparative Example 1 and Example 10 is:

[0142] Step 2 is: taking out the hydroxide anion exchange membrane from the KOH solution and immersing half of the hydroxide anion exchange membrane in water in a water tank, using a clamp to clamp the hydroxide anion exchange membrane in the water, so that the first electrode and the second electrode of the clamp are in close contact with the carbonated anion exchange membrane, and the distance between the first electrode and the second electrode is 1 cm;

[0143] The rest is the same as in Example 10.

[0144] The conductivity test results are shown in Table 1 below:

[0145] Table 1

[0146]

[0147]

[0148] Based on the test results of the above-mentioned embodiments 1 to 12 and comparative example 1, it can be seen that the conductivity values ​​measured by the test methods of embodiments 1 to 12 are closer to the conductivity of reference example 1, which shows that the test method of the embodiment of the present application can improve the accuracy of the conductivity test of the anion exchange membrane. The reason is: the anion exchange membrane is first completely immersed in water, and then the electrochemical impedance test is performed. During the test, the anion exchange membrane is always located in water, so that the anion exchange membrane is not in contact with the air, thereby reducing the reaction between the hydroxide ions on the anion exchange membrane and the carbon dioxide in the air, effectively improving the carbonation problem of the anion exchange membrane during the test, and improving the accuracy of the conductivity test of the anion exchange membrane.

[0149] From the comparison of Examples 1 to 9, Example 11, Example 12 and Example 10, it can be seen that before the electrochemical impedance test of the anion exchange membrane, the carbonated anion exchange membrane is completely immersed in water and the water is electrolyzed. When the water is electrolyzed, the carbonate ions and / or bicarbonate ions on the anion exchange membrane can leave the positively charged active groups of the anion exchange membrane and hydrolyze on the anode side to generate CO2 and OH - , CO2 is eventually discharged as gas, while OH - It can replace carbonate ions and / or bicarbonate ions to combine with the positively charged active groups of the anion exchange membrane, thereby converting carbonate ions and / or bicarbonate ions back into hydroxide ions, so as to reduce the effect of carbonation on the conductivity of the anion exchange membrane and improve the accuracy of the conductivity test of the anion exchange membrane; in addition, after the activation treatment, the electrochemical impedance test is directly performed on the activated anion exchange membrane immersed in water, which can isolate the air and the anion exchange membrane during the test, reduce the contact between the anion exchange membrane and the air, thereby improving the carbonation of the anion exchange membrane and further improving the accuracy of the conductivity test of the anion exchange membrane.

[0150] From the comparison between Examples 1 to 9 and Examples 11 and 12, it can be seen that when the anion exchange membrane is activated, the carbonated anion exchange membrane in the sample device to be tested is completely immersed in water, so that the carbonate ions and bicarbonate ions on the entire anion exchange membrane can be converted back into hydroxide ions. At the same time, the contact between the anion exchange membrane and the air can be reduced, thereby reducing the generation of new carbonate ions and bicarbonate ions by the anion exchange membrane during the activation process and the test process, thereby reducing the effect of carbonation on the conductivity of the anion exchange membrane and improving the accuracy of the conductivity test of the anion exchange membrane.

[0151] From the comparison between Examples 1 to 3 and Examples 4 and 5, it can be seen that during the constant voltage activation treatment, setting the time and voltage of the constant voltage activation treatment within a suitable range can further ensure the activation effect and improve the accuracy of the conductivity test of the anion exchange membrane.

[0152] From the comparison between Examples 6 to 7 and Examples 8 and 9, it can be seen that during the constant current activation treatment, setting the time and current of the constant current activation treatment within a suitable range can further ensure the activation effect and improve the accuracy of the conductivity test of the anion exchange membrane.

[0153] The embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for testing the conductivity of an anion exchange membrane, characterized in that: The following steps are involved: providing an anion exchange membrane having hydroxide ions; Completely immersing the anion exchange membrane in water; An electrochemical impedance test is performed on the anion exchange membrane completely immersed in the water to obtain the resistance of the anion exchange membrane, so as to calculate the conductivity of the anion exchange membrane through the resistance.

2. The testing method according to claim 1, characterized in that: The testing method specifically comprises the following steps: providing the anion exchange membrane; Completely immersing the anion exchange membrane in water and electrolyzing the water to obtain an activated anion exchange membrane; An electrochemical impedance test is performed on the activated anion exchange membrane completely immersed in the water to obtain the resistance of the anion exchange membrane, so as to calculate the conductivity of the anion exchange membrane through the resistance.

3. The testing method according to claim 2, characterized in that: The step of completely immersing the anion exchange membrane in water and electrolyzing the water specifically comprises: Fixing the anion exchange membrane between the first electrode and the second electrode of the fixture so that the anion exchange membrane contacts the first electrode and the second electrode to obtain a sample device to be tested; Placing the sample device to be tested in the water so that the water completely immerses the anion exchange membrane in the sample device to be tested; A power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water to obtain the activated anion exchange membrane.

4. The testing method according to claim 3, characterized in that: The activation treatment is a constant voltage activation treatment; The power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water. Specifically, the steps include: The positive electrode and the negative electrode of the power supply device are electrically connected to the first electrode and the second electrode respectively, and the power supply device applies a constant voltage to the water; A current curve showing the change of current with time during the activation process is obtained, and when the slope of the current curve is less than 0.1, it is judged that the activation is complete.

5. The testing method according to claim 3, characterized in that: The activation treatment is a constant current activation treatment; The power supply device is electrically connected to the first electrode and the second electrode, and the power supply device applies voltage or current to the water to electrolyze the water. Specifically, the steps include: The positive electrode and the negative electrode of the power supply device are electrically connected to the first electrode and the second electrode respectively, and the power supply device applies a constant current to the water; A voltage curve showing the voltage changing with time during the activation process is obtained, and when the slope of the voltage curve is less than 0.1, it is determined that the activation is complete.

6. The testing method according to claim 2 or 3, characterized in that: The activation treatment is a constant voltage activation treatment, the voltage of the constant voltage activation treatment is 3V-10V, and the time of the constant voltage activation treatment is 6h-30h.

7. The testing method according to claim 6, characterized in that: The protection current of the constant voltage activation treatment is 0.5A-1.0A.

8. The testing method according to claim 2 or 3, characterized in that: The activation treatment is a constant current activation treatment, the current of the constant current activation treatment is 400 μA-2000 μA, and the time of the constant current activation treatment is 15h-40h.

9. The testing method according to claim 8, characterized in that: The protection voltage of the constant current activation treatment is 8V-10V.

10. The testing method according to any one of claims 3 to 5, characterized in that: The steps of the electrochemical impedance test specifically include: An electrochemical workstation is electrically connected to the first electrode and the second electrode, and the resistance is measured by the electrochemical workstation.

11. The testing method according to claim 10, characterized in that: The conditions of the electrochemical impedance test are: the test temperature is 75° C.-85° C., and / or the disturbance voltage is 0.1 mV-10 mV, and / or the test frequency is 0.1 MHz-5 MHz.

12. The testing method according to claim 10, characterized in that: The calculation formula of the conductivity is: σ=L / a*b*R; Where, σ is the conductivity, in mS / cm; L is the distance between the first electrode and the second electrode, in cm; a is the width of the anion exchange membrane, in cm; b is the thickness of the anion exchange membrane, in cm; R is the resistance, in Ω.

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