An electrochemical test device
By designing a novel sample loading module and a circulating water bath for electrochemical testing, the problem of leakage in sealing samples such as bipolar plates was solved, achieving accuracy and repeatability of test results, and making it suitable for various test areas and temperature controls.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- STAR HYDROGEN (SHANGHAI) TECH CO LTD
- Filing Date
- 2023-02-17
- Publication Date
- 2026-07-21
AI Technical Summary
Existing electrochemical testing devices struggle to effectively seal test samples with wavy flow channels on their surfaces, such as bipolar plates, leading to leakage problems that affect the accuracy and repeatability of test results and pose a risk of equipment damage. Furthermore, it is difficult to control the test area and electrolyte temperature.
An electrochemical testing device was designed, which uses a novel sample loading module that is compressed and sealed, combined with a circulating water bath, to ensure that the test sample is in full contact with the electrolyte, and controls the test area and temperature through a combined structure.
It improves the accuracy and repeatability of test results, reduces the risk of leakage, adapts to different test area requirements, and can precisely control electrolyte temperature, reducing equipment damage.
Smart Images
Figure CN116223361B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of electrochemical testing technology, and in particular to an electrochemical testing device that can be used to test the corrosion resistance of sample coatings. Background Technology
[0002] Proton exchange membrane fuel cells (PEMFCs) can directly convert chemical energy into electrical energy through electrochemical reactions. They also have advantages such as low-temperature operation (70–90°C), high power density, and zero pollutant emissions, making them one of the most promising power sources in transportation.
[0003] As a crucial component of proton exchange membrane fuel cells (PEMFCs), bipolar plates not only serve as the electrical connection between the individual fuel cells in the stack but also supply reactant gases and remove heat and water generated during the reaction via flow channels on their surfaces. Therefore, they are often referred to as the skeleton of the fuel cell stack. Given the importance of bipolar plates and the harsh operating environment, researching the corrosion resistance of bipolar plate coatings is essential to ensuring the stack's operating efficiency and lifespan.
[0004] Currently, corrosion resistance testing of product coatings primarily utilizes a three-electrode electrolytic cell. During testing, the test sample is typically sealed with a rubber ring, exposing only the test surface. Then, the sample is placed near the bottom of the electrolytic cell and immersed in the electrolyte for testing. For test samples with flat surfaces, this sealing method usually achieves good sealing results. However, due to the wavy flow channel structure of the bipolar plate surface and the height of these channels, simple rubber ring sealing can easily lead to electrolyte leakage during testing due to inadequate sealing. This results in a low test success rate, making it difficult to guarantee the consistency and repeatability of bipolar plate coating corrosion resistance test results. Furthermore, leakage during testing can easily damage the testing equipment, posing a high testing risk. Therefore, existing electrolytic cells are often only suitable for testing samples with flat surfaces. In addition, existing testing methods also have problems such as the relatively simple test area of the sample, the difficulty in controlling the effective test area by adjusting the size of the fixture, and the difficulty in ensuring the temperature of the electrolyte. Summary of the Invention
[0005] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide an electrochemical testing device.
[0006] To achieve the above objectives, the technical solution of the present invention is as follows:
[0007] An electrochemical testing device, comprising:
[0008] An electrolytic cell, which is equipped with a tank;
[0009] A sample loading module is provided on the top surface of the tank. The sample loading module has a loading cavity and a test window communicating with the loading cavity on the bottom surface of the sample loading module. The loading cavity is used to place the test sample, and the test sample is pressed and sealed on the test window. The exposed bottom surface of the test sample is in complete contact with the electrolyte injected into the tank through the test window.
[0010] The electrode module includes a first electrode and a second electrode. The first electrode is disposed on the sample loading module and is in contact with the top surface of the test sample. The second electrode is disposed in the tank and is located below the test window.
[0011] Furthermore, the sample loading module includes a first body and a second body. The first body passes through the top surface of the groove and has a loading cavity on its top surface. The bottom surface of the first body has a test window communicating with the bottom surface of the loading cavity. A first sealing ring is provided between the bottom surface of the test sample and the bottom surface of the loading cavity. The second body enters the loading cavity from the top surface of the first body and presses and seals the test sample onto the test window through the first sealing ring. The first electrode is disposed on the second body and contacts the top surface of the test sample when the second body presses the test sample.
[0012] Furthermore, a first mounting port is provided on the top surface of the groove, the first body is sealed and installed on the first mounting port and extends into the groove, and the second body forms a rotatable connection with the first body when it enters the loading cavity.
[0013] Furthermore, the first electrode includes a first sub-electrode and a second sub-electrode. The first sub-electrode is elastically inserted into the second body and extends from the bottom surface of the second body for elastic contact with the top surface of the test sample. The second sub-electrode is inserted into the second body and extends from the top surface of the second body. The first sub-electrode and the second sub-electrode are electrically connected.
[0014] Furthermore, a second sealing ring is provided between the bottom surface of the second body and the top surface of the test sample. When the second body enters the loading cavity, it is pressed and sealed with the top surface of the test sample by the second sealing ring.
[0015] Furthermore, a second mounting port is provided on the side of the tank, and the second electrode is sealed and mounted on the second mounting port, parallel to the bottom surface of the test sample.
[0016] Furthermore, a third mounting port is provided on the top of the tank, and a temperature detection module is sealed and installed on the third mounting port. The height of the third mounting port is higher than the bottom surface of the test sample.
[0017] Furthermore, an air guide module is also sealed and installed on the third mounting port.
[0018] Furthermore, a fourth mounting port is provided on the top of the tank, and a third electrode is sealed and mounted on the fourth mounting port. The height of the fourth mounting port is higher than the bottom surface of the test sample.
[0019] Furthermore, the tank is located in a circulating water bath.
[0020] As can be seen from the above technical solution, this invention, through the design of a novel sample loading module, achieves effective sealing by compressing the test sample. By placing the test sample above the electrolytic cell, it ensures full contact between the electrolyte and the bottom surface of the test sample during testing, while reducing the liquid pressure exerted by the electrolyte on the test sample. This effectively solves the problem of leakage during testing, ensuring the accuracy of test results, improving the success rate and repeatability of the test, and preventing cost waste caused by equipment damage due to leakage. Furthermore, by setting test windows on the sample loading module with a modular structure, not only can the test area be precisely controlled, but sample loading modules with test windows of different sizes can also be easily assembled to meet various test area requirements for different test samples. In addition, by using an external circulating water bath to fully cover the bottom and sides of the electrolytic cell, it is beneficial to accurately control the temperature of the electrolyte in the cell, further improving the accuracy of the test. Attached Figure Description
[0021] Figures 1-2 This is a schematic diagram of the structure of an electrochemical testing device according to a preferred embodiment of the present invention;
[0022] Figure 3 This is an exploded structural diagram of a sample loading module according to a preferred embodiment of the present invention. Detailed Implementation
[0023] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art. The terms "comprising" and similar expressions used herein mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, but does not exclude other elements or objects.
[0024] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0025] Please see Figures 1-2 , Figures 1-2 This is a schematic diagram of an electrochemical testing device according to a preferred embodiment of the present invention. Figures 1-2 As shown, an electrochemical testing device of the present invention includes several main structural components such as an electrolytic cell, a sample loading module 15, and an electrode module.
[0026] Please see Figures 1-2 The electrolytic cell is equipped with a tank 4. The tank 4 is a closed structure used to inject the electrolyte 5 for electrochemical testing.
[0027] Sample loading module 15 is used for sealed mounting of test sample 31 (reference) for electrochemical testing. Figure 3 The sample loading module 15 is located on the top surface of the tank 4, and the bottom surface of the test sample 31 installed in the sample loading module 15, that is, the test surface of the test sample 31, is exposed downward in the tank 4, so that the bottom surface of the test sample 31 can be in complete contact with the electrolyte 5 injected in the tank 4, that is, the bottom surface of the test sample 31 is below the liquid surface of the electrolyte 5.
[0028] The sample loading module 15 is provided with a loading cavity 28 (reference). Figure 3 The sample loading module 15 has a test window 27 on its bottom surface that communicates with the loading cavity 28. The loading cavity 28 is used to place the test sample 31, and the test sample 31 is pressed tightly in the loading cavity 28, so that the test sample 31 is pressed and sealed on the test window 27, and the bottom surface of the test sample 31 is exposed through the test window 27. In this way, the exposed bottom surface of the test sample 31 is in complete contact with the electrolyte 5 injected into the injection tank 4 through the test window 27.
[0029] The electrode module includes a first electrode 12 and a second electrode 26. The first electrode 12 is disposed on the sample loading module 15 and located outside the tank 4. The lower end of the first electrode 12 extends into the loading cavity 28 and contacts the top surface of the test sample 31 enclosed in the loading cavity 28. The second electrode 26 is disposed in the tank 4, located below the test window 27, and is immersed in the electrolyte 5.
[0030] The first electrode 12 can be used as the working electrode during testing, and the second electrode 26 can be used as an auxiliary electrode.
[0031] This invention can be used for electrochemical testing of test samples 31, such as plate-shaped (sheet-shaped) test samples. Test sample 31 can be, for example, a flat plate, an etched plate, or a curved plate, such as the metal bipolar plate of a proton exchange membrane fuel cell. This invention can test the corrosion resistance of the surface coating of test sample 31, but is not limited thereto.
[0032] Please see Figures 1-3 In some embodiments, the sample loading module 15 may include a first body 14 and a second body 13. The first body 14 passes through the top surface of the groove 4. The loading cavity 28 is disposed on the top surface of the first body 14, and the test window 27 is disposed on the bottom surface of the first body 14 and communicates with the bottom surface of the loading cavity 28.
[0033] When placing the test sample 31 into the loading cavity 28, a first sealing ring 32 needs to be placed between the bottom surface of the test sample 31 and the bottom surface of the loading cavity 28. The opening size of the first sealing ring 32 can generally correspond to the size of the test window 27, so that the first sealing ring 32 can be located on the bottom surface of the loading cavity 28 and surround the test window 27. The second body 13 can enter the loading cavity 28 from the top surface of the first body 14 to press the test sample 31 tightly, thereby pressing the test sample 31 against the bottom surface of the loading cavity 28, and sealing the test sample 31 to the test window 27 through the first sealing ring 32, leaving only a portion of the bottom surface of the test sample 31 located in the test window 27 exposed as the test surface to contact the electrolyte 5 injected in the tank 4 for testing.
[0034] Bipolar plates typically have a wavy flow channel structure with a certain height. Simply sealing them with rubber rings can easily lead to electrolyte leakage during testing due to inadequate sealing. This results in a low test success rate and makes it difficult to guarantee the consistency and repeatability of the bipolar plate coating corrosion resistance test results. Furthermore, leakage during testing can easily damage the testing equipment, thus posing a high testing risk. The novel sample loading module 15 designed in this invention can effectively seal special test samples 31, such as bipolar plates. By setting a first sealing ring 32 between the bottom surface of the test sample 31 and the bottom surface of the loading cavity 28, and by pressing the test sample 31, the material of the first sealing ring 32 can fully fill the uneven flow channel structure on the surface of the bipolar plate when it is deformed by compression, thus blocking the flow channel structure. This prevents the electrolyte 5 from seeping into the top surface of the bipolar plate test sample 31 through the bottom surface and flow channel structure exposed in the test window 27, which would otherwise cause the risk of test failure.
[0035] Meanwhile, by placing the test sample 31 above the tank 4, the liquid pressure generated by the electrolyte 5 on the test sample 31 can be greatly reduced, thus effectively solving the problem of leakage of the test sample 31 during the previous testing process.
[0036] Please see Figures 1-3 In some embodiments, the first electrode 12 may be disposed on the second body 13 and exposed on the bottom surface of the second body 13, so that it can contact the top surface of the test sample 31 when the second body 13 enters the loading cavity 28 of the first body 14 and presses the test sample 31.
[0037] In some embodiments, the first electrode 12 may include a first sub-electrode 122 and a second sub-electrode 121. The first sub-electrode 122 is elastically inserted into the second body 13 and extends from the bottom surface of the second body 13, for elastic contact with the top surface of the test sample 31 when the second body 13 enters the loading cavity 28 of the first body 14 and presses against the test sample 31. The second sub-electrode 121 is inserted into the second body 13 and extends from the top surface of the second body 13 for connection with the electrode clamp of the electrochemical workstation. An electrical connection is formed between the first sub-electrode 122 and the second sub-electrode 121.
[0038] In some embodiments, a first countersunk hole may be provided on the bottom surface of the second body 13, and a first sub-electrode 122 may be disposed in the first countersunk hole. An elastic element may be provided between the bottom end of the first countersunk hole and the first sub-electrode 122. A second countersunk hole may be provided on the top surface of the second body 13, and a second sub-electrode 121 may be disposed in the second countersunk hole. The first countersunk hole and the second countersunk hole may be connected by a channel provided in the second body 13, and the first sub-electrode 122 and the second sub-electrode 121 may be electrically connected by a wire provided in the channel.
[0039] In some embodiments, a second sealing ring 30 may be provided between the bottom surface of the second body 13 and the top surface of the test sample 31. When the second body 13 enters the loading cavity 28, it can be pressed and sealed against the top surface of the test sample 31 by the second sealing ring 30. By providing the second sealing ring 30, on the one hand, damage to the test sample 31 or itself can be avoided when the second body 13 enters the loading cavity 28 and presses against the test sample 31; on the other hand, it can act as a second sealing barrier. Once the first sealing ring 32 fails, the second sealing ring 30 can be used to continue to prevent the electrolyte 5 from penetrating to the top surface of the test sample 31.
[0040] In some embodiments, when the first sealing ring 32 and the second sealing ring 30 are horizontally placed in the loading cavity 28, they can form a clearance fit with the side wall of the loading cavity 28, and when they are squeezed by the second body 13, they can deform and tighten on the side wall of the loading cavity 28, thereby further enhancing the sealing effect.
[0041] In some embodiments, the test sample 31 may be machined to have a shape that forms a clearance fit with the sidewall of the loading cavity 28.
[0042] In some embodiments, a first mounting port 11 may be provided on the top surface of the tank 4, and the first body 14 may be sealed and installed on the first mounting port 11 and extend into the tank 4.
[0043] In some embodiments, the second body 13 may form a rotatable connection with the first body 14 when it enters the loading cavity 28.
[0044] Please see Figure 3 In some embodiments, the first body 14 may adopt a first flange-neck structure. The first flange-neck structure may include a connected first flange portion 141 and a first flange neck 142. The loading cavity 28 can sequentially enter the first flange portion 141 and the first flange neck 142 from the end face of the first flange portion 141 (shown as the left end face in the figure); the test window 27 is located on the end face of the first flange neck 142 (shown as the right end face in the figure) and enters the first flange neck 142, communicating with the bottom surface of the loading cavity 28. The first body 14 can enter the first mounting port 11 through the first flange neck 142 and form a threaded connection with the first mounting port 11.
[0045] In some embodiments, a third sealing ring may be provided at the junction of the first flange neck 142 and the first flange portion 141 to form a sealed connection between the first body 14 and the first mounting port 11, preventing the electrolyte 5 in the tank 4 from overflowing from the first mounting port 11.
[0046] In some embodiments, the second body 13 may adopt a second necked flange structure. The second necked flange structure may include a connected second flange portion 131 and a second flange neck 132. A first countersunk hole may be provided on the end face (shown as the right end face in the figure) of the second flange neck 132, and a first sub-electrode 122 is disposed in the first countersunk hole. An elastic element may be provided between the bottom end of the first countersunk hole and the first sub-electrode 122. By releasing the elastic force of the elastic element, the first sub-electrode 122 can be pushed to partially protrude from the surface of the first countersunk hole. A second countersunk hole may be provided on the end face (shown as the left end face in the figure), and a second sub-electrode 121 is disposed in the second countersunk hole. The first countersunk hole and the second countersunk hole may be connected by a channel provided in the second flange portion 131 and the second flange neck 132. A wire may be provided in the channel, and both ends of the wire may extend through the channel and be electrically connected to the first sub-electrode 122 located in the first countersunk hole and the second sub-electrode 121 located in the second countersunk hole, respectively. The second body 13 can enter the loading cavity 28 on the first body 14 through the second flange neck 132, and can be rotatedly connected to the first body 14 through a threaded connection.
[0047] Thus, when the second body 13 rotates into the loading cavity 28 of the first body 14 through the second flange neck 132, it can gradually press the surface of the test sample 31 by continuous rotation and the deformation of the first sealing ring 32 and the second sealing ring 30. Finally, a good seal is established between the bottom surface of the test sample 31 (shown as the right side in the diagram) and the test window 27 of the first body 14, and between the top surface of the test sample 31 (shown as the left side in the diagram) and the second body 13. During this process, the first sub-electrode 122 exposed on the second flange neck 132 gradually contacts the top surface of the test sample 31 and gradually retracts into the first countersunk hole under the pressure of the test sample 31, causing the elastic element to contract under pressure. When the second body 13 rotates to its final position, the elastic force applied to the first sub-electrode 122 by the elastic element ensures effective elastic contact between the first sub-electrode 122 and the top surface of the test sample 31.
[0048] In some embodiments, the second flange portion 131 and the second flange neck 132 may be separate structures and may be assembled to form an integral second body 13 to facilitate the processing of channels and laying of wires thereon, as well as to facilitate the connection of wires to the first sub-electrode 122 and the second sub-electrode 121.
[0049] In some embodiments, anti-slip textures 33 may be provided on the outer periphery of the first flange portion 141 and the second flange portion 131 to facilitate the gripping of the outer periphery of the first flange portion 141 and the second flange portion 131 for the installation and tightening of the test sample 31. The installation and tightening status of the test sample 31 can be quantitatively detected using measuring tools such as torque wrenches, and rotation position indicators can be marked on the first body 14 and the second body 13.
[0050] The size of the test window 27 determines the test area of the test sample 31. Therefore, the test area of the sample can be adjusted in various ways by changing the processing size of the test window 27 on the first body 14. Furthermore, multiple first bodies 14 that match the second body 13 can be used, and test windows 27 of different sizes can be processed on each first body 14. According to the testing needs, a first body 14 with test windows 27 of the corresponding size can be selected to cooperate with the second body 13 to install the test sample 31.
[0051] In some embodiments, the test sample 31 can be a disc, and the first sealing ring 32 and the second sealing ring 30 can be annular, such as... Figure 3 As shown. After the test sample 31 is installed in the sample loading module 15, it will be positioned horizontally above the tank 4, so that the exposed bottom surface of the test sample 31 is parallel or substantially parallel to the liquid surface of the electrolyte 5.
[0052] In some embodiments, the test sample 31, the first sealing ring 32, and the second sealing ring 30 may also be polygonal, irregularly shaped, etc.
[0053] In some embodiments, the test window 27 may be a circular window.
[0054] In some embodiments, the test window 27 may also be a polygonal window, an irregularly shaped window, etc.
[0055] In some embodiments, the first sub-electrode 122 and the second sub-electrode 121 may be conductive probes, etc.
[0056] In some embodiments, the elastic element may be a spring or the like.
[0057] Please see Figures 1-2 In some embodiments, a second mounting port 23 may be provided on the side of the tank 4; the second electrode 26 may be sealed and mounted on the second mounting port 23 by the first sealing cover 24, and the surface of the second electrode 26 shall be parallel to the bottom surface of the test sample 31, so that the installed second electrode 26 is horizontally suspended in the tank 4.
[0058] The second electrode 26 can be led out through the first sealing cap 24 for connection to the electrode clamp of the electrochemical workstation.
[0059] In some embodiments, the second electrode 26 can be tightly mounted on the first sealing cover 24 by the first fastening screw 25; the first sealing cover 24 and the second mounting port 23 can be connected by threads and can be sealed by the fourth sealing ring.
[0060] In some embodiments, the second electrode 26 may be rectangular, circular, or the like.
[0061] In some embodiments, the projection of the installed second electrode 26 in the vertical direction can completely cover the test window 27 (see reference). Figure 2 ).
[0062] In some embodiments, a third mounting port 19 may be provided on the top of the tank 4. For example, the third mounting port 19 may be provided on the top surface of the tank 4. Furthermore, the height of the third mounting port 19 is higher than the bottom surface height of the test sample 31 in the sample loading module 15 mounted on the first mounting port 11.
[0063] In some embodiments, a temperature detection module may be sealed and installed on the third mounting port 19 to monitor the temperature change of the electrolyte 5 during the test, so as to control the temperature of the electrolyte 5.
[0064] In some embodiments, the temperature detection module may be a temperature sensor, or a thermometer 21, etc.
[0065] In some embodiments, the thermometer 21 can be sealed and mounted on the third mounting port 19 via the second sealing cover 18.
[0066] In some embodiments, the thermometer 21 can be tightly mounted on the second sealing cover 18 by the second fastening screw 16; the second sealing cover 18 and the third mounting port 19 can be connected by threads and sealed by the fifth sealing ring.
[0067] In some embodiments, a gas guiding module may also be sealed and installed on the third mounting port 19. The gas guiding module may include an inlet gas pipe and an outlet gas pipe. Gas can be introduced into the tank 4 through the inlet gas pipe and discharged from the tank 4 through the outlet gas pipe, so as to meet the testing conditions of the surface coating (e.g., bipolar plate surface coating) of the test sample 31 under different atmospheres.
[0068] In some embodiments, the air inlet pipe and the air outlet pipe can be tightly installed on the second sealing cover 18 by the third fastening screw 17 and the fourth fastening screw 29, respectively.
[0069] In some embodiments, the first mounting port 11 can be directly disposed on the top surface of the tank 4. Furthermore, a vertical pipe 20 connected to the tank 4 can be formed upward on the top surface of the tank 4, and the upper opening of the vertical pipe 20 can be used as a third mounting port 19, so that the height of the third mounting port 19 is higher than the height of the first mounting port 11, thereby making the height of the third mounting port 19 higher than the bottom surface height of the test sample 31 in the sample loading module 15 mounted on the first mounting port 11.
[0070] In some embodiments, a fourth mounting port 8 may be provided on the top of the tank 4, and a third electrode 7 may be sealed and mounted on the fourth mounting port 8. The third electrode 7 may be used as a reference electrode.
[0071] In some embodiments, the height of the fourth mounting port 8 is higher than the bottom height of the test sample 31 in the sample loading module 15 mounted on the first mounting port 11.
[0072] In some embodiments, a bent tube 6 connected to the tank 4 can be formed on the side of the tank 4 near the top surface, with the opening of the bent tube 6 facing upwards as a fourth mounting port 8. The height of the formed fourth mounting port 8 is higher than the bottom surface height of the test sample 31 in the sample loading module 15 mounted on the first mounting port 11. The bent tube 6 is used as a reference electrode placement tube. The bent tube 6 may have connected horizontal and vertical sections. The third electrode 7 can be sealed and mounted on the fourth mounting port 8 via a third sealing cap 9, and is located in the vertical section of the bent tube 6, such as... Figure 1 As shown.
[0073] In other embodiments, the fourth mounting port 8 can also be directly disposed on the top surface of the tank 4. This can be achieved by forming a straight tube connected to the tank 4 upwards on the top surface of the tank 4, with the upper opening of the straight tube serving as the fourth mounting port 8. This ensures that the height of the fourth mounting port 8 is higher than the height of the first mounting port 11, thereby making the height of the fourth mounting port 8 higher than the bottom surface height of the test sample 31 in the sample loading module 15 mounted on the first mounting port 11. The third electrode 7 can be sealed and installed within the straight tube.
[0074] The vertical pipe 20 and the bent pipe 6 (or straight pipe) are connected to the tank body 4, and thus also become part of the tank body 4.
[0075] In some embodiments, the third electrode 7 can be tightly mounted on the third sealing cover 9 by the fifth fastening screw 10; the third sealing cover 9 and the fourth mounting port 8 can be connected by threads and sealed by the sixth sealing ring.
[0076] The third electrode 7 can be led out through the third sealing cover 9 so as to be connected to the electrode clamp of the electrochemical workstation.
[0077] In some embodiments, the third electrode 7 may be arranged parallel to the first electrode 12, and the third electrode 7 may be arranged perpendicular to the second electrode 26, that is, the first electrode 12 may be arranged perpendicular to the second electrode 26.
[0078] In some embodiments, the third electrode 7 may be positioned as close as possible to the test sample 31 to further improve test accuracy.
[0079] In some embodiments, the third electrode 7 may be a cylindrical electrode or the like.
[0080] In some embodiments, the fourth mounting port 8 and the third mounting port 19 may be arranged on both sides of the first mounting port 11, and form a U-shaped tube structure with the fourth mounting port 8 and the third mounting port 19 as the top openings respectively through the bend 6 and the vertical pipe 20 connected to the groove 4, and the U-shaped tube structure communicates with the bottom surface of the test sample 31 installed on it through the first mounting port 11.
[0081] In some embodiments, the first sub-electrode 122 may be disposed at the center of the second body 13, and the second sub-electrode 121 may be disposed at a position near the edge of the second body 13.
[0082] In some embodiments, the axis of the third electrode 7, the axis of the second sub-electrode 121, the axis of the first sub-electrode 122, and the center of the second electrode 26 can be located in the same vertical plane, such as... Figure 2 As shown.
[0083] In some embodiments, one of the third mounting port 19 and the fourth mounting port 8 can be reused as the injection port for the electrolyte 5. When the electrolyte 5 is injected into the tank 4 through the third mounting port 19 or the fourth mounting port 8, the liquid level of the electrolyte 5 can be observed using the U-shaped tube structure formed between the third mounting port 19 and the fourth mounting port 8. This allows for convenient control to ensure that the liquid level of the electrolyte 5 injected into the tank 4 is higher than the bottom surface of the test sample 31. This ensures that the exposed bottom surface of the test sample 31 located on the test window 27 can fully contact the electrolyte 5 without being immersed too deeply in the electrolyte 5, which would cause the electrolyte 5 to exert excessive liquid pressure on the bottom surface of the test sample 31.
[0084] Alternatively, independent liquid injection ports can be set at other locations on the tank body 4 other than the third installation port 19 and the fourth installation port 8.
[0085] In some embodiments, the first sealing ring 32 to the sixth sealing ring may be a rubber sealing ring or the like.
[0086] In some embodiments, the tank 4 may be an acrylic tank 4 or the like. Furthermore, the bent pipe 6 with the third mounting port 19 and the vertical pipe 20 with the fourth mounting port 8 may be acrylic tubes or the like made of the same material as the tank 4, and may be formed into an integral structure with the tank 4 through processing.
[0087] In some embodiments, the groove 4 can be a circular groove 4, such as Figure 2 As shown; or, the groove 4 can also be a polygonal groove 4, etc.
[0088] In some embodiments, the materials of the first body 14 and the second body 13 of the sample loading module 15, as well as the materials of the first sealing cover 24 to the third sealing cover 9, may be polytetrafluoroethylene, etc.
[0089] Please see Figures 1-2 In some embodiments, the tank 4 may be located in a circulating water bath 2. Circulating water 3 at a certain temperature may be introduced into the circulating water bath 2 to heat the electrolyte 5 in the tank 4 and control the temperature of the electrolyte 5 to be maintained within the required test temperature range.
[0090] In some embodiments, the circulating water bath 2 may adopt a shape corresponding to the tank 4 to fully cover the bottom and sides of the tank 4, thereby improving heating uniformity. Furthermore, the top surface of the circulating water bath 2 may be flush with or close to the top surface of the tank 4, and at least cover the horizontal section of the bend 6.
[0091] In some embodiments, the circulating water bath 2 may be provided with an inlet 1 and an outlet 22. The inlet 1 may be located on the side of the circulating water bath 2 near the bottom, and the outlet 22 may be located on the side of the circulating water bath 2 near the top. Furthermore, the inlet 1 and outlet 22 may be located on opposite sides of the circulating water bath 2 to enhance the water circulation effect.
[0092] In some embodiments, the circulating water bath 2 may be made of plexiglass or the like. Furthermore, the circulating water bath 2 may be integrally formed with the tank body 4.
[0093] For example, the typical operating temperature of a PEMFC fuel cell is 70–90°C. When testing the bipolar plates of a PEMFC fuel cell, specific temperature conditions are required during the corrosion resistance test to accurately reflect the corrosion resistance of the bipolar plate surface coating under specific temperature conditions. This can be achieved by introducing external circulating water heated to 70–90°C into the circulating water bath 2 through inlet 1 and outflowing through outlet 22 for recycling, thus circulating the water in the circulating water bath 2 and effectively controlling the temperature of the electrolyte 5 in the tank 4. Simultaneously, a thermometer 21 can be installed on the third mounting port 19 to monitor the temperature change of the electrolyte 5 during the test. Furthermore, an air inlet pipe and an air outlet pipe can also be equipped on the third mounting port 19 to meet the requirements for testing the bipolar plate coating under different atmospheres.
[0094] In use, this invention begins by selecting a sample loading module 15 with a test window 27 of the desired size. The first sealing ring 32 is placed into the loading cavity 28 on the first body 14 of the sample loading module 15 and laid flat on the bottom surface of the loading cavity 28 surrounding the test window 27. Next, the test sample 31 is placed into the loading cavity 28, ensuring the bottom surface of the test sample 31 is in contact with the first sealing ring 32. Then, the second sealing ring 30 is placed above the test sample 31. Next, the second body 13 is gradually screwed into the loading cavity 28, connecting with the first body 14 and ensuring elastic contact between the first sub-electrode 122 of the first electrode 12 and the top surface of the test sample 31, thus forming the working electrode for the test. Finally, the first body 14, containing the second body 13, is threadedly sealed onto the first mounting port 11 of the tank 4, so that the first electrode 12, serving as the working electrode, is located outside the tank 4. Then, the second electrode 26, which serves as an auxiliary electrode, is installed and connected to the second mounting port 23 on the side of the tank body 4 through the first sealing cover 24, so that the second electrode 26 is located below the first electrode 12 and parallel to the bottom surface of the test sample 31 exposed in the test window 27.
[0095] After the test sample 31 and the first electrode 12 and the second electrode 26 are installed, the electrolyte 5 can be injected into the transparent tank 4 through the third mounting port 19 on the vertical pipe 20 located on the top surface of the tank 4. The electrolyte 5 level in the vertical pipe 20 below the third mounting port 19 should be observed to ensure it is higher than the bottom surface of the test sample 31. For example, the electrolyte 5 can be added until the level is at least above the first mounting port 11. This is primarily to ensure that the bottom surface of the test sample 31 is in full contact with the electrolyte 5 during testing, and this structural design helps reduce the risk of leakage during testing of materials such as bipolar plates.
[0096] When the liquid level of the injected electrolyte 5 reaches a certain height difference with the bottom surface of the test sample 31, the second sealing cover 18 containing the thermometer 21 can be threadedly connected to the third mounting port 19, so that the lower measuring end of the thermometer 21 is at a height position close to the bottom surface of the test sample 31.
[0097] Next, the third electrode 7, which serves as the reference electrode, can be installed and connected to the fourth mounting port 8 above the bent pipe 6, which communicates with the tank body 4 and serves as the reference electrode placement tube, through the third sealing cover 9. The third electrode 7, which serves as the reference electrode, is close to the first electrode 12, which serves as the working electrode, thereby reducing the influence of the ohmic drop of the electrolyte solution 5 on the test results.
[0098] Finally, connect the first electrode 12 (second sub-electrode 121) to the third electrode 7 to the three electrode clips of the electrochemical workstation, and you can start testing, for example, the corrosion resistance of bipolar plate surface coatings, and record the data during the test.
[0099] In summary, the present invention has the following advantages:
[0100] (1) By changing the structure of the electrolytic cell so that the test sample 31 is located above the electrolytic cell, the liquid pressure acting on the sample can be reduced. By optimizing the liquid level difference between the electrolyte 5 at the first mounting port 11 and the third mounting port 19 in the electrolytic cell, the electrolyte 5 can be in full contact with the test sample 31 during the test, which ensures the accuracy of the test results. At the same time, it can reduce the risk of leakage during the corrosion resistance test of coatings such as bipolar plates, and improve the success rate and repeatability of the test.
[0101] (2) It can avoid damage to the testing equipment caused by seepage and reduce testing costs;
[0102] (3) It can be applied to various test area requirements for different samples;
[0103] (4) The electrolytic cell is covered by a circulating water bath 2, which helps to better control the temperature of the electrolyte 5 in the electrolytic cell.
[0104] This invention is widely applicable to relatively accurate electrochemical testing of products with different surface morphologies, including bipolar plates, flat plates, etched plates, and curved plates with a certain thickness, and is suitable for widespread application.
[0105] While embodiments of the present invention have been described in detail above, it will be apparent to those skilled in the art that various modifications and variations can be made to these embodiments. However, it should be understood that such modifications and variations fall within the scope and spirit of the invention as set forth in the claims. Furthermore, the invention described herein may have other embodiments and can be implemented or carried out in various ways.
Claims
1. An electrochemical testing device, characterized in that, include: An electrolytic cell, which is equipped with a tank; A sample loading module is provided on the top surface of the tank. The sample loading module has a loading cavity and a test window communicating with the loading cavity on the bottom surface of the sample loading module. The loading cavity is used to place the test sample, and the test sample is pressed and sealed on the test window. The exposed bottom surface of the test sample is in complete contact with the electrolyte injected into the tank through the test window. The electrode module includes a first electrode and a second electrode. The first electrode is disposed on the sample loading module and is in contact with the top surface of the test sample. The second electrode is horizontally suspended in the tank and located below the test window, and is immersed in the electrolyte. The sample loading module comprises a first body and a second body. The first body extends through the top surface of the groove and has a loading cavity on its top surface. A test window communicating with the bottom surface of the loading cavity is located on the bottom surface of the first body. A first sealing ring is provided between the bottom surface of the test sample and the bottom surface of the loading cavity. The second body enters the loading cavity from the top surface of the first body, pressing and sealing the test sample against the test window using the first sealing ring. A second sealing ring is also provided between the bottom surface of the second body and the top surface of the test sample. When the second body enters the loading cavity, it forms a rotatable connection with the first body and is pressed and sealed against the top surface of the test sample using the second sealing ring. The test sample, the first sealing ring, and the second sealing ring form a clearance fit with the sidewall of the loading cavity. When the second sealing ring is squeezed by the second body, it expands and tightens against the side wall of the loading cavity through deformation. The opening size of the first sealing ring corresponds to the size of the test window, so that the first sealing ring is located on the bottom surface of the loading cavity and surrounds the test window. By pressing the test sample, the first sealing ring is deformed under pressure, and its material enters the uneven flow channel structure on the surface of the test sample to fully fill it, blocking the flow channel structure and preventing the electrolyte from seeping into the top surface of the test sample through the bottom surface of the test sample exposed in the test window and its flow channel structure. Once the first sealing ring fails, the second sealing ring continues to prevent the electrolyte from penetrating into the top surface of the test sample. By placing the test sample above the tank, the liquid pressure generated by the electrolyte on the test sample is reduced.The top surface of the tank is provided with a first mounting port. The first body is sealed and installed on the first mounting port and extends into the tank. The top of the tank is also provided with a third mounting port. A temperature detection module and a gas guiding module are sealed and installed on the third mounting port. A vertical pipe connected to the tank is formed upward on the top surface of the tank, and the upper opening of the vertical pipe serves as the third mounting port. This ensures that the height of the third mounting port is higher than that of the first mounting port, thereby making the height of the third mounting port higher than that of the sample loading module installed on the first mounting port. The bottom surface height of the test sample in the block, the top of the tank is also provided with a fourth mounting port, the fourth mounting port is sealed and installed with a third electrode, and a bend tube connected to the tank is formed on the side of the tank near the top surface of the tank, with the opening of the bend tube facing upwards, serving as the fourth mounting port, so that the height of the fourth mounting port is higher than the bottom surface height of the test sample, the third electrode is located in the vertical tube section provided by the bend tube, the vertical tube and the bend tube are part of the tank, the fourth mounting port and the third mounting port are respectively arranged in the first On both sides of the mounting port, a U-shaped tube structure is formed by the bent pipe and the vertical pipe connected to the tank, with the fourth mounting port and the third mounting port respectively opening upwards. The U-shaped tube structure communicates with the bottom surface of the test sample mounted on it through the first mounting port. One of the third and fourth mounting ports is reused as an electrolyte injection port. When electrolyte is injected into the tank through the third or fourth mounting port, the U-shaped tube structure is used to observe the electrolyte level and control the electrolyte level in the tank to be higher than that of the test sample. The bottom surface of the sample is designed to ensure that the exposed bottom surface of the test sample on the test window can fully contact the electrolyte without being too deeply immersed in the electrolyte, which would create excessive liquid pressure on the bottom surface of the test sample. The first body is threadedly connected to the first mounting port. By setting multiple first bodies that match the second body, and processing test windows of different sizes on each first body, the test sample can be installed by selecting a first body with a test window of the appropriate size according to the testing needs, thus achieving diversified adjustment of the test area.
2. The electrochemical testing device according to claim 1, characterized in that, The first electrode is disposed on the second body and comes into contact with the top surface of the test sample when the second body presses the test sample.
3. The electrochemical testing device according to claim 2, characterized in that, The first electrode includes a first sub-electrode and a second sub-electrode. The first sub-electrode is elastically inserted into the second body and extends from the bottom surface of the second body for elastic contact with the top surface of the test sample. The second sub-electrode is inserted into the second body and extends from the top surface of the second body. The first sub-electrode and the second sub-electrode are electrically connected.
4. The electrochemical testing device according to claim 1, characterized in that, The tank has a second mounting port on its side, and the second electrode is sealed and mounted on the second mounting port, parallel to the bottom surface of the test sample.
5. The electrochemical testing device according to claim 1, characterized in that, The tank is located in a circulating water bath.