Combined device and method for measuring surface resistance and bubble point of alkaline hydrogen production diaphragm

Abstract

The invention discloses a combined device and method for measuring the surface resistance and bubble point of an alkaline hydrogen production diaphragm. Comprising an end plate assembly with a transparent observation window, a first electrolyte containing cavity and a second electrolyte containing cavity which are located on the two sides of a diaphragm respectively, a diaphragm fixing plate used for clamping the diaphragm and limiting the effective testing area, an electrode plate with a hole in the center, a multi-layer sealing gasket and a fastening assembly, and is provided with a liquid injection / drainage interface, a liquid drainage interface and an air inlet interface. According to the testing method of the device, under the condition that the clamping and pressing states of the diaphragm are not changed, the surface resistance of the diaphragm can be measured in a set atmosphere / bubble-containing electrolyte environment, and then bubble point pressure testing is achieved by emptying the containing cavity on one side and maintaining wetting liquid covering on the other side. And the transparent observation window is used for observing the infiltration state of the diaphragm and the bubble generation and attachment behaviors in real time, so that the accuracy of judging the area resistance and the bubble point is improved, and a consistent microscopic state basis is provided for establishing the association between the bubble point and the area resistance.

Description

Technical Field

[0001] This invention belongs to the field of testing and evaluation technology of alkaline water electrolysis hydrogen production diaphragm, specifically relating to a device and method that can measure the surface resistance and bubble point pressure of alkaline water electrolysis diaphragm in situ under the same clamping and pressing conditions in a controlled atmosphere with the assistance of visualization. Background Technology

[0002] The areal resistivity and bubble point pressure of an alkaline water electrolysis diaphragm are two key indicators characterizing its service performance. Areal resistivity reflects the diaphragm's resistance to OH-. - The degree of conduction resistance directly affects the energy consumption of the electrolyzer; the bubble point pressure characterizes the gas barrier capability and pore size distribution of the diaphragm, and is an important basis for assessing the operational safety boundary. During the research and development process, accurately obtaining the above two parameters and establishing their corresponding relationship helps guide the optimization of diaphragm formulation, microstructure, and process window.

[0003] Currently, resistivity and bubble point pressure are typically measured separately: resistivity is often obtained using electrochemical impedance spectroscopy in an electrochemical cell, while bubble point pressure is usually measured in a separate bubble point testing device / instrument. Because these two types of testing devices differ in boundary conditions such as electrode structure, clamping method, compressive stress distribution, wetting method, and the state of the test medium, using the same diaphragm repeatedly can easily cause micropore deformation, changes in compressive state, or damage to the coating / fiber structure. Using different diaphragms, the non-uniformity of the sample makes it difficult to ensure that the two tests correspond to the same microscopic state. Furthermore, most test chambers are opaque, making the testing process invisible and preventing observation of the diaphragm wetting degree and bubble adhesion on the diaphragm surface. This makes it difficult to quantify the specific impact of bubbles on actual parameter measurements, thus reducing the consistency between the test results and actual gas-liquid two-phase operating conditions.

[0004] Therefore, there is an urgent need for a comprehensive testing device and method that can achieve in-situ combined use of area resistivity and bubble point pressure under the same clamping condition, and can visualize the diaphragm wetting and bubble-out process. Summary of the Invention

[0005] To overcome the problems of existing technologies, this invention provides a visualized in-situ combined testing device and method for the surface resistance and bubble point of alkaline water electrolysis diaphragms. This aims to solve the problems of limited testing environments, lack of process visibility, and poor comparability of results due to the need for step-by-step testing in existing technologies. This invention employs a high-voltage resistant transparent end plate and an integrated sealing design, combined with a controllable gas-liquid switching system, enabling the same diaphragm to undergo surface resistance and bubble point tests sequentially under the same clamping condition. This method eliminates secondary assembly errors through in-situ testing and utilizes visualization to simulate and observe resistance changes under real electrolysis conditions (including bubble-filled electrolyte), while also accurately capturing the instantaneous bubble point formation with the naked eye or a camera, thereby obtaining high-precision and highly correlated diaphragm performance data.

[0006] Specifically, to achieve the above objectives, the present invention provides a visual in-situ coupled testing device for measuring the surface resistance and bubble point pressure of a membrane in alkaline electrolyzed water, comprising: an insulating transparent end plate (15), first and second insulating electrolyte cavities (1, 13), a first electrode plate (3) and a second electrode plate (11), a first membrane fixing plate (5) and a second membrane fixing plate (9), multilayer sealing gaskets (2, 4, 6, 8, 10, 12, 14), and fastening components; The insulating transparent end plate (15) is used for sealing and providing a test window; a drain valve (18) is provided at the bottom of the end plate; The first and second insulating electrolyte cavities (1, 13) are located on both sides of the diaphragm to be tested, and are provided with through holes in the middle and electrolyte inlet and outlet ports; The first electrode plate (3) and the second electrode plate (11) are respectively disposed inside the first cavity (1) and the second cavity (13). The first electrode plate (3) and the second electrode plate (11) are provided with tabs for electrical connection, and their central areas are provided with a mesh through-hole structure. The first diaphragm fixing plate (5) and the second diaphragm fixing plate (9) are used to clamp the diaphragm to be tested and limit the effective test area; The multilayer sealing gaskets (2, 4, 6, 8, 10, 12, 14) are disposed between adjacent components to achieve a seal; The fastening assembly includes an insulating bolt (16) and a nut (17) for pressing the above components along the thickness direction to form a sealed test chamber; Among them, by switching the valve path of the drain valve (18) and the air inlet (19), the device can perform surface resistance measurement in the electrolyte environment while keeping the diaphragm clamping and pressing state unchanged, and perform bubble point pressure measurement after emptying the second cavity (13); the transparent observation window is used to visualize the generation of bubble point and the behavior of bubble adhesion.

[0007] Preferably, the thickness of the insulating transparent end plate (15) is 10-20 mm, the thickness of the insulating electrolyte cavity (1, 13) is 5-20 mm, the thickness of the diaphragm fixing plate (5, 9) is 2-5 mm, the thickness of the electrode sheet (3, 11) is 0.3-1.0 mm, the thickness of the insulating sealing gasket is 0.2-0.5 mm, and the size of the bolt is greater than the thickness of the stacked parts.

[0008] Preferably, the center of the first cavity (1) and the second cavity (13) is provided with a through hole coaxial with the through hole of the diaphragm fixing plate, and the size of each through hole is the same and smaller than the outer size of the diaphragm to be tested, so that the effective test area is limited by the through hole.

[0009] Preferably, the insulating transparent end plate (15) has inlet / outlet gas / liquid pipes, and the pipes have drain valves. The end plate material is selected from transparent materials such as polymethyl methacrylate, perfluoroethylene propylene, and polycarbonate. The first insulating electrolyte cavity (13) and / or the second insulating electrolyte cavity (1) have liquid / gas inlets, and the material is selected from polytetrafluoroethylene. The first diaphragm fixing plate (9) and / or the second diaphragm fixing plate (5) are selected from polytetrafluoroethylene. The sealing gasket material is selected from one or more of polytetrafluoroethylene film, polyetheretherketone film, or polyphenylene sulfide film. The fastening assembly is an insulating fastener, and its material is selected from polyetheretherketone or polyphenylene sulfide.

[0010] Preferably, the central opening of the first electrode sheet (3) and / or the second electrode sheet (11) is a mesh-like or porous array structure to promote gas-liquid mass transfer; the electrode sheet material is selected from one or more of nickel, nickel alloy, stainless steel or titanium.

[0011] Preferably, the air inlet (19) is connected to an external gas supply system, which includes a gas source A, a flow regulating component B, a pressure monitoring component C, and a safety pressure relief component D.

[0012] An apparatus and method for determining the surface resistivity and bubble point of an alkaline hydrogen production diaphragm, comprising the following steps: (1) Diaphragm pretreatment: Soak the diaphragm to be tested in an alkaline solution (such as 30 wt% KOH) to fully wet it; (2) Assembly: Stack the end plate assembly (15), sealing gasket, first cavity (1), sealing gasket, first electrode plate (3), sealing gasket, first diaphragm fixing plate (5), sealing gasket, diaphragm to be tested, sealing gasket, second diaphragm fixing plate (9), sealing gasket, second electrode plate (11), sealing gasket, and second cavity (13) in sequence, and tighten them evenly with a torque of 2-5 N·m to form a sealed test cavity; (3) Electrochemical test: Electrolyte was injected into the first cavity (1) and the second cavity (13) respectively. The electrode tabs were connected to the electrochemical workstation. The AC impedance method was used for testing, with a frequency range of 1 Hz to 10 Hz. 6 Hz; (4) Data processing: Read the real axis intercept of the Nyquist plot at the high frequency end to calculate the resistance value, and then calculate the resistance value according to the formula R. A =(R Z R0)×A, where R Z For the diaphragm test resistor, R0 is the blank device resistance, and A is the effective test area; the calculated R... A The sheet resistance of the diaphragm under a specific atmosphere; (5) Medium venting: Open the drain valve to completely drain the alkaline solution in the second insulating electrolyte cavity (13) while keeping the device assembly state unchanged; (6) Air tightness check: Check the air tightness and liquid tightness of the nylon plastic pipe connections at each interface of the external piping system; (7) Bubble point test: Keep the alkaline solution in the first insulating electrolyte cavity (1) unchanged, or replace the alkaline solution with pure water, n-butanol or other media, and the amount of liquid injected just fills the first insulating electrolyte cavity (1); connect the gas circuit system to slowly ventilate and pressurize the other side of the diaphragm, and record the pressure value when the first continuous bubble is observed on the diaphragm surface, which is the bubble point.

[0013] Preferably, when testing surface resistance, the electrolyte is an alkaline electrolyte, and is either a basic alkaline solution or a gas-containing electrolyte pre-bubbled to saturation with oxygen or hydrogen to simulate the gas-liquid two-phase environment of the electrolytic cell.

[0014] Preferably, the test temperature is controlled between 25 and 80 °C, and the electrochemical test parameters are set as follows: under open-circuit potential conditions, the AC perturbation amplitude is 10 mV, and the frequency scan range is 10... 6 Hz to 1 Hz.

[0015] Assembly and usage method of the device: The insulating transparent end plate, insulating sealing gasket, first insulating electrolyte cavity, insulating sealing gasket, first electrode plate, insulating sealing gasket, first diaphragm fixing plate, insulating sealing gasket, diaphragm to be tested, insulating sealing gasket, second diaphragm fixing plate, insulating sealing gasket, second electrode plate, insulating sealing gasket, and second insulating electrolyte cavity are stacked sequentially from bottom to top. Then, using a torque wrench and bolt nuts, the test device is tightened through the bolt holes to complete the assembly of the electrolytic cell. The torque wrench is used for tightening, with a torque of 2-5 N·m. After checking the sealing performance, the test can begin.

[0016] This invention provides a method for testing diaphragm performance using the aforementioned apparatus, and simulates actual operating conditions by injecting electrolytes with different gas saturations. The method includes the following steps: (1) Pre-test preparation: The membrane to be tested is fully immersed in an alkaline solution (e.g., 30wt% KOH) for activation pretreatment (e.g., 24 hours). After that, it is assembled into the test device, ensuring that all components fit tightly together.

[0017] (2) Simulated operating condition test: Electrolyte is added to the test device. To simulate different operating conditions, the added electrolyte is in two states: a) Basic alkaline solution: A conventional alkaline solution that does not contain any intentionally saturated gases.

[0018] b) Saturated oxygen alkaline solution: an alkaline solution that has been saturated with oxygen by bubbling beforehand.

[0019] (3) Sheet resistance test: Connect the device's tabs to the electrochemical workstation. Under each electrolyte condition, activate the electrochemical workstation's AC impedance test function. Set appropriate parameters (e.g., open circuit voltage, 10mV amplitude, frequency scan range from 10...). 6 (Hz to 1 Hz). Record impedance data multiple times and plot the Nyquist plot.

[0020] (4) Data processing: The intercept of this graph in the high-frequency region with the real axis (Z' axis) is the total resistance of the system. Subtracting the blank resistance of the device, it can be regarded as the diaphragm resistance. Multiplying the measured diaphragm resistance by the area of ​​the test area gives the sheet resistance of the diaphragm under this specific alkaline atmosphere.

[0021] (5) Medium venting: Open the drain valve to completely drain the alkaline solution in the second insulating electrolyte cavity (13) while keeping the device assembly state unchanged; (6) Air tightness test: Check the air tightness and liquid tightness of the nylon plastic pipe connections at each interface of the external piping system; (7) Bubble Point Test: ① Keep the alkaline solution in the first insulating electrolyte cavity (1) unchanged, or replace the alkaline solution with pure water, n-butanol or other media, and the amount of liquid injected just fills the first insulating electrolyte cavity (1) so that one side of the diaphragm is completely covered below the pure water surface.

[0022] ② Connect the gas pipe in area C of the pressure unit to the second insulating electrolyte cavity (13) to form a channel (19) that can supply gas to area D of the in-situ joint test unit. Turn on the air compressor in area A of the gas supply unit and the mass flow meter in area B of the control unit in sequence to slowly pressurize the second insulating electrolyte cavity (13) of the test unit D.

[0023] ③ Observe the liquid surface state on the side of the first insulating electrolyte cavity (1). When the first bubble is observed to be generated on the diaphragm surface and continuous bubbles are guided out, record the pressure value at this time, which is the bubble point pressure.

[0024] Compared with the prior art, the present invention has the following significant advantages: 1. In-situ combined testing eliminates assembly errors: This invention enables the sequential completion of surface resistivity and bubble point tests on the same device and at the same workstation. It avoids the secondary clamping required for diaphragm transfer in traditional step-by-step testing, and eliminates diaphragm micropore deformation, physical damage, or changes in contact state caused by disassembly and assembly. This ensures the diaphragm is in a completely consistent state of mechanical compression and wetting during both tests, significantly improving the accuracy and correlation of the data.

[0025] 2. Visualization-assisted testing enhances accuracy: The integrated insulated transparent endplate solves the problem of traditional "black box" testing. In bubble point testing, testers can directly observe the moment the first continuous bubble forms on the diaphragm surface; in sheet resistance testing, the wetting state of the electrolyte and the adhesion of bubbles can be visually monitored, improving the reliability of sheet resistance testing.

[0026] 3. Simulating real-world operating conditions provides more valuable data: By injecting a pre-saturated gas (hydrogen / oxygen) electrolyte into the device, this invention can simulate the gas-liquid two-phase environment of the anode and cathode chambers of an electrolytic cell. Combined with visual observation, the influence of bubble adhesion on the diaphragm surface resistance can be quantitatively analyzed, providing a reliable basis for evaluating the performance degradation of the diaphragm under actual operating conditions.

[0027] 4. Scientific structure and high integration: The device adopts a vertical stacking structure and a single-sided precision cavity design, utilizing gravity to ensure uniform liquid surface coverage. A single system can complete key characterization of two types of diaphragms, shortening the testing cycle and facilitating standardization. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the testing equipment of the present invention in its assembled state.

[0029] Figure 2 This invention provides Figure 1 A schematic diagram of the structure of device D in its unassembled and disassembled state.

[0030] Figure 3 This invention provides Figure 1 A cross-sectional view of the insulating transparent end plate at point D in the test equipment in a specific embodiment.

[0031] Figure 4 This invention provides Figure 1 A cross-sectional view of the insulating electrolyte cavity at point D in the specific embodiment of the test equipment.

[0032] Figure 5 This invention provides Figure 1 A cross-sectional view of the electrode sheet at point D in a specific embodiment of the testing equipment.

[0033] Figure 6 This invention provides Figure 1 A cross-sectional view of the diaphragm fixing plate at point D in the test equipment in a specific embodiment.

[0034] Figure 7 This is the Nyquist curve of the non-diaphragm blank test in the example under the 30wt% KOH alkaline solution environment.

[0035] Figure 8 This is the Nyquist curve of the electrochemical impedance spectroscopy (EIS) of the membrane under test in a 30wt% KOH alkaline environment in the example.

[0036] Figure 9 This is the Nyquist curve of the non-diaphragm blank test in the embodiment under saturated oxygen alkaline solution environment.

[0037] Figure 10 This is an example of an AC impedance spectrum (Nyquist) curve obtained from a blank test of a diaphragm under saturated oxygen alkaline solution conditions. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0039] Example This embodiment uses the measurement of the bubble point and surface resistivity of a commercial PPS diaphragm to illustrate the implementation process of this method.

[0040] (1) Preparation before testing 1) Prepare two states of electrolyte: basic alkaline solution and saturated oxygen alkaline solution; 2) A commercial diaphragm was immersed in 30 wt% KOH basic alkaline solution / saturated oxygen alkaline solution for 24 h; 3) Use tweezers to remove a commercial diaphragm and remove excess alkali solution from the diaphragm surface; (2) Device assembly and electrochemical testing a. Assembly of the device for testing the blank resistance without a diaphragm ①Reference Figure 2 Assemble the testing device in sequence: The insulating transparent end plate-15, insulating sealing gasket-14, second insulating electrolyte cavity-13, insulating sealing gasket-12, second electrode plate-11, insulating sealing gasket-10, second diaphragm fixing plate-9, insulating sealing gasket-8, diaphragm to be tested-7, insulating sealing gasket-6, first diaphragm fixing plate-5, insulating sealing gasket-4, first electrode plate-3, insulating sealing gasket-2, and first insulating electrolyte cavity-1 are stacked from bottom to top, and then tightened using bolts-16 and nuts-17; the tightening torque is 2-5 N·m, and the area of ​​the diaphragm to be tested is 3×3 cm². 2 After assembling the electrolytic cell, connecting the gas pipeline, and checking the seal, testing can begin.

[0041] ② Test device connection Add basic alkaline solution or saturated oxygen alkaline solution to the first insulating electrolyte cavity and the second insulating electrolyte cavity, and then connect the tabs of the first electrode plate-11 and the second electrode plate-3 to the electrochemical workstation.

[0042] ③ Electrochemical testing For each electrolyte condition, AC impedance testing was performed after the system stabilized. Test conditions: open circuit potential, 10 mV sinusoidal disturbance, frequency range 10... 6 Hz-1 Hz. The Nyquist curve obtained from the basic alkaline solution is as follows: Figure 7 As shown, the Nyquist curve obtained from saturated oxygen alkaline solution is as follows: Figure 9 As shown. The real intercept of each curve at the high-frequency end is read as R0.

[0043] b. Assembly of the apparatus for testing diaphragm resistance ①Reference Figure 2 Assemble the testing device in sequence: Specifically, the diaphragm-7 to be tested is placed between the insulating sealing gasket-8 and the insulating sealing gasket-6; The insulating transparent end plate-15, insulating sealing gasket-14, second insulating electrolyte cavity-13, insulating sealing gasket-12, second electrode plate-11, insulating sealing gasket-10, second diaphragm fixing plate-9, insulating sealing gasket-8, diaphragm to be tested-7, insulating sealing gasket-6, first diaphragm fixing plate-5, insulating sealing gasket-4, first electrode plate-3, insulating sealing gasket-2, and first insulating electrolyte cavity-1 are stacked from bottom to top, and then tightened using bolts-16 and nuts-17; the tightening torque is 2-5 N·m, and the area of ​​the diaphragm to be tested is 3×3 cm². 2 Complete the assembly of the electrolytic cell and connect the gas pipeline, such as... Figure 2 As shown, after checking the seal, the test can begin.

[0044] ② Test device connection Add basic alkaline solution or saturated oxygen alkaline solution to the first insulating electrolyte cavity and the second insulating electrolyte cavity, and then connect the tabs of the first electrode plate-11 and the second electrode plate-3 to the electrochemical workstation. ③ Electrochemical testing For each electrolyte condition, AC impedance testing was performed after the system stabilized. Test conditions: open circuit potential, 10 mV sinusoidal disturbance, frequency range 10... 6 Hz-1 Hz. The Nyquist curve obtained from the basic alkaline solution is as follows: Figure 8 As shown, the Nyquist curve obtained from saturated oxygen alkaline solution is as follows: Figure 10 As shown. The real intercept of each curve at the high-frequency end is read as R. Z .

[0045] (3) Data Analysis: According to the formula for calculating surface resistance R A =(R Z R0)×A, where R Z R0 is the real intercept of the test curve; R0 is the blank resistance value without the test diaphragm; A is the effective test area of ​​the diaphragm, which is 9 cm² in this device.

[0046] The diaphragm was tested according to the above-described surface resistivity test setup method. The test results are shown in Table 1.

[0047] Table 1. Test results of membrane surface resistance under different electrolyte conditions

[0048] (4) Results and Discussion: As can be seen, the diaphragm surface resistivity measured in the saturated gas alkali solution is significantly higher than that in the basic alkali solution. This indicates that the adhesion of bubbles to the diaphragm surface or pores does indeed increase the resistance to ion transport.

[0049] (5) Medium venting: After the test is completed, open the drain valve-18 of the pipeline connected to the insulated transparent end plate to completely drain the alkaline solution in the cavity. During this process, keep the assembly state of the device unchanged and only drain the liquid medium inside the cavity.

[0050] (6) Alkali replacement: ① Inject pure water into the first insulating electrolyte cavity using a syringe.

[0051] ② Continuously inject pure water to flush the pipeline and cavity to replace the trace amounts of alkaline solution remaining in the membrane pores and pipeline.

[0052] (7) Air tightness test: Check the air tightness and liquid tightness of the nylon plastic pipe connections at each interface of the external piping system; (8) Test the bubble point: ① Operate the air compressor (A) and adjust the mass flow meter (B) to control the gas supply rate.

[0053] ② Keep the drain valve (18) closed, and inject pure water or other media such as alkaline water or n-butanol into the cavity through the injection port at the top of the upper cavity. The amount of liquid injected should just fill the cavity on one side of the transparent observation window, so that one side of the diaphragm is completely covered below the pure water surface.

[0054] ③ Immediately open the mass flow meter (B) valve to slowly introduce gas into the inlet (19) and gradually increase the pressure.

[0055] ④ Carefully observe the state of the liquid surface on the pure water side. When the first continuous bubble is observed to form on the diaphragm surface, record the pressure value displayed on the pressure gauge (C) at this time, and denote it as the bubble point pressure P. bp .

[0056] ⑤ The test results after repeating the operation three times are shown in Table 2.

[0057] Table 2. Bubble point test results of the diaphragm

[0058] In summary, the method of this invention successfully enables continuous measurement of the bubble point and surface resistivity of the diaphragm within the same device without disassembling the diaphragm. Verification through examples shows that the device exhibits excellent sealing and corrosion resistance, effectively avoiding physical damage to the diaphragm and differences in wetting state caused by secondary clamping in traditional step-by-step testing. This provides a standardized and comprehensive testing scheme for the performance evaluation of alkaline water electrolysis diaphragms.

[0059] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. An apparatus and method for determining the surface resistivity and bubble point of an alkaline hydrogen production diaphragm, characterized in that, include: Insulating transparent end plate (15), first and second insulating electrolyte cavities (1, 13), first electrode plate (3) and second electrode plate (11), first diaphragm fixing plate (5) and second diaphragm fixing plate (9), multilayer sealing gaskets (2, 4, 6, 8, 10, 12, 14) and fastening components; The insulating transparent end plate (15) is used to seal and provide a test window, allowing the tester to directly observe the distribution of bubbles inside the device; a drain valve (18) is provided at the bottom of the end plate. The first and second insulating electrolyte cavities (1, 13) are located on both sides of the diaphragm to be tested, and are provided with through holes in the middle and electrolyte inlet and outlet ports; The first electrode plate (3) and the second electrode plate (11) are respectively disposed inside the first cavity (1) and the second cavity (13). The first electrode plate (3) and the second electrode plate (11) are provided with tabs for electrical connection, and their central areas are provided with a mesh through-hole structure. The first diaphragm fixing plate (5) and the second diaphragm fixing plate (9) are used to clamp the diaphragm to be tested and limit the effective test area; The multilayer sealing gaskets (2, 4, 6, 8, 10, 12, 14) are disposed between adjacent components to achieve a seal; The fastening assembly includes an insulating bolt (16) and a nut (17) for pressing the above components along the thickness direction to form a sealed test chamber; Among them, by switching the valve path of the drain valve (18) and the air inlet (19), the device can perform surface resistance measurement in the electrolyte environment while keeping the diaphragm clamping and pressing state unchanged, and perform bubble point pressure measurement after emptying the second cavity (13); the transparent observation window is used to visualize the generation of bubble point and the behavior of bubble adhesion.

2. The testing apparatus according to claim 1, characterized in that, The thickness of the insulating transparent end plate (15) is 10-20 mm, the thickness of the insulating electrolyte cavity (1, 13) is 5-20 mm, the thickness of the diaphragm fixing plate (5, 9) is 2-5 mm, the thickness of the electrode plate (3, 11) is 0.3-1.0 mm, the thickness of the insulating sealing gasket is 0.2-0.5 mm, and the size of the bolt is greater than the thickness of the parts stacked together.

3. The testing apparatus according to claim 1 or 2, characterized in that, The first cavity (1) and the second cavity (13) are both provided with through holes coaxial with the through holes of the diaphragm fixing plate, and the size of each through hole is the same and smaller than the outer size of the diaphragm to be tested, so that the effective test area is limited by the through holes.

4. The testing apparatus according to any one of claims 1 to 3, characterized in that, The insulating transparent end plate (15) has inlet and outlet gas / liquid pipelines, and the pipelines have drain valves. The end plate material is selected from transparent materials such as polymethyl methacrylate, perfluoroethylene propylene, and polycarbonate. The first insulating electrolyte cavity (1) and / or the second insulating electrolyte cavity (13) have liquid / gas inlets, and the material is selected from polytetrafluoroethylene. The first diaphragm fixing plate (9) and / or the second diaphragm fixing plate (5) are selected from polytetrafluoroethylene. The sealing gasket material is selected from one or more of polytetrafluoroethylene film, polyetheretherketone film, or polyphenylene sulfide film. The fastening component is an insulating fastener, and its material is selected from polyetheretherketone or polyphenylene sulfide.

5. The testing apparatus according to any one of claims 1 to 3, characterized in that: The central opening of the first electrode sheet (3) and / or the second electrode sheet (11) is a mesh or porous array structure to promote gas-liquid mass transfer; the electrode sheet material is selected from one or more of nickel, nickel alloy, stainless steel or titanium.

6. The testing apparatus according to any one of claims 1 to 3, characterized in that: The air inlet (19) is connected to an external gas supply system, which includes a gas source A, a flow regulating component B, a pressure monitoring component C, and a safety pressure relief component D.

7. A method for determining the resistivity of an alkaline electrolyzed water diaphragm and the bubble point pressure using the testing apparatus described in any one of claims 1 to 7, characterized in that, Includes the following steps: (1) Diaphragm pretreatment: Immerse the diaphragm to be tested in an alkaline solution to fully wet it; (2) Assembly: Stack the end plate assembly (15), sealing gasket, first cavity (1), sealing gasket, first electrode plate (3), sealing gasket, first diaphragm fixing plate (5), sealing gasket, diaphragm to be tested, sealing gasket, second diaphragm fixing plate (9), sealing gasket, second electrode plate (11), sealing gasket, and second cavity (13) in sequence, and tighten them evenly with a torque of 2-5 N·m to form a sealed test cavity; (3) Electrochemical test: Electrolyte was injected into the first cavity (1) and the second cavity (13) respectively. The electrode tabs were connected to the electrochemical workstation. The AC impedance method was used for testing, with a frequency range of 1 Hz to 10 Hz. 6 Hz; (4) Data processing: Read the real axis intercept of the Nyquist plot at the high frequency end to calculate the resistance value, and then calculate the resistance value according to the formula R. A =(R Z R0)×A, where R Z For the diaphragm test resistor, R0 is the blank device resistance, and A is the effective test area; the calculated R... A The sheet resistance of the diaphragm under a specific atmosphere. (5) Medium venting: Open the drain valve to completely drain the alkaline solution in the second insulating electrolyte cavity (13) while keeping the device assembly state unchanged; (6) Air tightness check: Check the air tightness and liquid tightness of the nylon plastic pipe connections at each interface of the external piping system; (7) Bubble point test: Keep the alkaline solution in the first insulating electrolyte cavity (1) unchanged, or replace the alkaline solution with pure water or n-butanol medium, and the amount of liquid injected just fills the first insulating electrolyte cavity (1); connect the gas circuit system to slowly ventilate and pressurize the other side of the diaphragm, and record the pressure value when the first continuous bubble is observed to be generated on the diaphragm surface, which is the bubble point.

8. The method according to claim 7, characterized in that: When testing surface resistance, the electrolyte is an alkaline electrolyte, and is either a basic alkaline solution or a gas-containing electrolyte pre-bubbled to saturation with oxygen or hydrogen to simulate the gas-liquid two-phase environment of the electrolytic cell.

9. The method according to claim 7 or 8, characterized in that: The test temperature was controlled between 25 and 80 °C. The electrochemical test parameters were set as follows: under open-circuit potential conditions, the AC perturbation amplitude was 10 mV, and the frequency scan range was 10... 6 Hz to 1 Hz.

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