A current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing

Abstract

The present invention belongs to the technical field of fuel cells, and discloses a current collecting high temperature piezoelectric sensor for testing solid oxide fuel cells. The device can be used to study the effective power generation area of ​​1.0 cm <supgt;2< / supgt;左右的实验室纽扣固体氧化物燃料电池,系统包括:固定装置的法兰;密封电池的夹具;测试电池高温膨胀应力的测压器平台垫片;产生感应电流的压电效应材料;采集导出电流的集流柱。本发明提供的一种用于固体氧化物燃料电池测试的集流高温压电传感器,采用内埋耐高温压电效应材料和集流柱的方法,可以对燃料电池的的热膨胀应力进行测试和监控,同时便捷的导出电极的电流,方便电池检测时的组装步骤,降低组装时的漏气风险,测试时间短、过程简单。

Description

Technical Field

[0001] The present invention belongs to the technical field of fuel cell testing, and particularly relates to a testing device for a solid oxide fuel cell. Background Art

[0002] A solid oxide fuel cell (SOFC, Solid Oxide Fuel Cell) is a device that directly converts the chemical energy in fuel into electrical energy through an electrochemical reaction at high temperature. Due to its high-temperature characteristics, a relatively large number of fuel types can be selected, such as hydrogen, methane, propane, ammonia, methanol, etc. The most typical one is the air and hydrogen fuel cell. It has the advantages of high energy efficiency, flexible fuel, and modular assembly.

[0003] A button solid oxide fuel cell is composed of an anode, an electrolyte, and a cathode. Before actual production, the solid oxide fuel cell needs to undergo various performance tests before it can be used for power generation. The button solid oxide fuel cell is the smallest unit of a large solid oxide fuel cell and is mainly used to test the material properties of the solid oxide fuel cell and explore the working principle of the solid oxide fuel cell. The test contents include electrical properties such as the open-circuit voltage, load current / output power, and impedance of the battery. Efficiently exporting the current generated by the battery, measuring the sealing pressure during battery installation, and the pressure generated by material thermal expansion during high-temperature operation are very important for the performance of the battery and the thermal matching of the materials. Currently, the current of the battery is mainly exported by using a fixture shell or connecting external silver wires, platinum wires, etc. Each test requires cleaning the shell or reconnecting the wires. The expansion pressure strain of the battery during high-temperature operation will cause problems such as cracking of the electrolyte electrode detachment. Since the battery operates in a sealed high-temperature fixture, it is difficult to measure the thermal expansion pressure of the battery through external devices. Generally, separate measurements need to be carried out through a dilatometer or in-situ calibration with a high-temperature electron microscope.

[0004] Through the above analysis, the problems and defects existing in the prior art are as follows: The testing device for the button solid oxide fuel cell uses a fixture shell for conduction or requires external wires. The fixture shell is generally made of stainless steel, which has a large resistance and affects the accuracy of battery performance detection. The external wire method requires reconnecting each time, resulting in a cumbersome and time-consuming testing process and being unfavorable for the sealing of the battery. Separate measurements through a dilatometer or in-situ calibration with a high-temperature electron microscope will increase the measurement cost, and the separate measurement is different from the actual state of the solid oxide fuel cell during operation. When the battery operates at high temperature, there is not only thermal expansion, but also electron and ion exchange on the surface and inside of the battery. If the pressure applied during assembly is too large, it will squeeze the reaction sites. The increase in thermal expansion stress during high-temperature operation may cause unbalanced stress and lead to battery rupture, increasing the testing risk. This results in an unrigorous testing process, and there will be some gaps between the obtained test results and the true performance of the battery. Summary of the Invention

[0005] In view of the problems existing in the prior art, the present invention provides a test fixture for a solid oxide fuel cell.

[0006] The present invention is implemented as follows. A current collector high-temperature piezoelectric sensor for testing a solid oxide fuel cell includes:

[0007] A fixed flange, made of high-temperature resistant stainless steel, is provided with a series of fixed threaded holes thereon for fixing the test fixture of the solid oxide fuel cell and ensuring stability under high-temperature conditions;

[0008] An air inlet chamber, tightly connected to the fixed flange, is internally coated with a corrosion-resistant coating, used for supplying oxygen and fuel gas, and adopts a double-layer structure to have a pressure-holding and heat-insulating function;

[0009] A fixture composed of upper and lower parts, tightly fitted with the fixed flange, is internally provided with a groove for placing the battery and covered with a heat-insulating material, used for clamping and assembling the solid oxide fuel cell, while reducing heat loss;

[0010] A current collector column, arranged inside the fixture, made of a highly conductive material, contacts the electrodes of the solid oxide fuel cell, and has a threaded structure to increase the contact area with the battery, used for efficiently leading out the current generated by the electrodes;

[0011] A pressure gauge, arranged on one side of the fixture, contacts the solid oxide fuel cell, made of a high-temperature stable piezoelectric ceramic material, and is externally equipped with a protective shell to prevent external damage, used for real-time collecting the thermal expansion force of the solid oxide fuel cell under high-temperature conditions.

[0012] A plurality of gas supply ports are provided in the air inlet chamber, and each gas supply port is equipped with an independent flow meter and a pressure sensor, respectively used for inputting oxygen and fuel gas, and each gas supply port is provided with a microporous diffusion plate to ensure uniform gas distribution, and the air inlet chamber is provided with an electronic control valve to achieve remote precise control of the gas flow rate and pressure.

[0013] The pressure gauge is internally made of a high-temperature stable piezoelectric material, such as lead zirconate titanate (PZT), and has a design matching the thermal expansion coefficient of the solid oxide fuel cell to ensure precise pressure measurement under high-temperature conditions. At the same time, the outside of the pressure gauge is equipped with a temperature sensor and a thermocouple, used for real-time monitoring of its working temperature and avoiding errors caused by thermal stress. For the above test device, preferably, the fixed flange device includes:

[0014] The flange is divided into upper and lower parts, punched according to the positions of the inlet and outlet pipes, and the hole diameter matches the diameter of the gas transmission pipe, allowing the gas pipe to pass through. In addition, holes are opened according to the fixing bolts for assembly fixing and pressurization.

[0015] For the above-mentioned test device, preferably, the intake chamber includes:

[0016] The intake chamber is divided into upper and lower parts, and is composed of an intake pipe, an outlet pipe, a shunt partition plate and a sealing sheet. The intake pipe is used to introduce air or fuel gas into the fixture to contact the surface of the battery electrode. The shunt partition plate is used to maintain pressure and guide the reacted gas to the outlet pipe. The sealing sheet is used for sealing;

[0017] For the above-mentioned test device, preferably, the fixture includes:

[0018] The fixture is divided into upper and lower parts, and is made of an insulating material with a low coefficient of thermal expansion, such as zirconia. Holes are drilled according to the positions of the current collector posts and the pressure gauges, and are used to load the battery and install the current collector posts and the pressure gauges;

[0019] For the above-mentioned test device, preferably, the current collector bar includes:

[0020] The current collector posts are four high-conductive materials with a low coefficient of thermal expansion, such as graphite, silver, platinum, etc., which contact the current collector network on the electrode surface and are used to conduct the current out. They can be replaced when the material is oxidized and fails.

[0021] For the above-mentioned test device, preferably, the pressure gauge includes:

[0022] The pressure gauge is composed of a platform gasket, a conduction pillar, a piezoelectric effect material, a signal acquisition and amplification processor, a communication interface and a data line, and data acquisition and processing software. The platform gasket is in close contact with the battery surface and is connected to the conduction pillar. The conduction pillar conducts the expansion stress of the battery to the piezoelectric effect material. The weak current generated by the piezoelectric effect material under pressure is received by the signal acquisition and amplification processor and undergoes noise reduction processing, and is uploaded to the data acquisition and processing software on the computer side through the communication interface and the data line.

[0023] The platform gasket and the conduction pillar are made of an insulating material with an extremely low coefficient of thermal expansion, such as quartz, zirconia, silicon carbide, silicon nitride polymer, etc.

[0024] The piezoelectric effect material maintains volume stability in the range of 300 - 1000 °C and can generate a high normalized output voltage, such as strontium lithium borate (LBS), barium lithium tantalate (BLT), lead cerium titanate (PCT), and lead zirconate titanate (PZT).

[0025] Combined with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solution to be protected by the present invention are:

[0026] First, the present invention provides a detection fixture for a button solid oxide fuel single cell. By embedding a conductive material and a piezoelectric induction pressure measuring device into the fixture, a device with integrated current collection and pressure measurement is made. Compared with existing test devices, it can collect current inexpensively and conveniently, measure thermal expansion stress, and control the pressure exerted on the cell during assembly. It avoids the human error caused by the repeated installation of conductive wires during detection and the additional device during the measurement of thermal expansion stress.

[0027] Second, the present invention can simultaneously collect current, measure thermal expansion stress, and control the pressure exerted on the cell during assembly. It reduces the failure rate of experiments caused by the decrease in airtightness due to the repeated installation and connection of conductive wires during product detection, and also reduces the risk of battery rupture caused by the increase in expansion stress during high-temperature operation due to excessive applied sealing pressure. It avoids the additional device used during the measurement of the thermal expansion rate of solid oxide fuel cells. The test cost is low, the process is simple, and the repeated installation of connecting components during product detection is reduced, enhancing the airtightness during detection.

[0028] Third, the expected benefits and commercial value after the transformation of the technical solution of the present invention are as follows: The present invention avoids the additional device used during the measurement of the thermal expansion rate of solid oxide fuel cells and reduces the increase in detection costs caused by the decrease in airtightness and battery rupture. Therefore, this patented device can reduce the detection cost and time of solid oxide fuel cells.

[0029] The technical solution of the invention fills the domestic and foreign industry technical gaps: Currently, there is no solid oxide fuel cell test device that can simultaneously collect current and measure expansion stress.

[0030] Does the technical solution of the present invention solve the technical problems that people have always been eager to solve but have never succeeded in? Solid oxide fuel cells operate in a sealed high-temperature environment, and detection instruments cannot penetrate from the outside for measurement. Ordinary pressure detectors cannot obtain accurate measurement results in a high-temperature environment. This device solves this problem by embedding a high-temperature-resistant piezoelectric sensor.

[0031] Fourth, it is difficult to monitor the thermal expansion force of a battery in real time with traditional solid oxide fuel cell test methods. The present invention can monitor the thermal expansion force of a solid oxide fuel cell in a high-temperature working state in real time and accurately, providing a deeper understanding of the battery's working state.

[0032] Compared with traditional test methods, this sensor greatly simplifies the test process of solid oxide fuel cells and improves the test efficiency.

[0033] Traditional fixing methods may cause movement or displacement of solid oxide fuel cells at high temperatures, while this fixing flange can ensure the stability of the cells throughout the testing process, thus ensuring the accuracy of the data. The designed fixing flange can be applied to solid oxide fuel cells of various different sizes and shapes, providing a wider range of applications.

[0034] This intake chamber can not only supply oxygen and fuel gas, but also has a pressure-holding function, which can maintain a fixed working pressure to ensure that the cell operates under constant conditions.

[0035] Traditional gas supply methods may pose a risk of leakage at high temperatures and pressures. The design of this intake chamber ensures the safe supply of gas throughout the testing process, reducing the leakage risk during the testing process.

[0036] The significant technological advancements brought by the present invention mainly focus on improving the accuracy, efficiency, stability, compatibility, and safety of testing, providing strong technical support for the research and development and application of solid oxide fuel cells.

[0037] Fifth, the significant technological advancements achieved by the system provided by the present invention may include but are not limited to the following points:

[0038] 1) Precise pressure measurement: Using piezoelectric effect materials to measure thermal expansion stress, the stress changes during the operation of the cell can be monitored and recorded very precisely. This precise measurement is crucial for optimizing the structural design and material selection of fuel cells.

[0039] 2) Good airtight performance: Through a well-designed seal sheet and separator system, the device can maintain excellent airtightness under high-temperature and high-pressure conditions, reducing the risk of inaccurate test data or equipment damage caused by gas leakage.

[0040] 3) Optimized current collection design: Using silver mesh current collection nets and nickel foam current collection nets reduces the contact resistance during cell operation and improves the current collection efficiency, which has a positive impact on improving the energy conversion efficiency and stability of fuel cells.

[0041] 4) Modular components: The design of the components takes into account the convenience and compatibility of assembly, enabling the device to be quickly assembled and disassembled, facilitating different test requirements and rapid sample replacement.

[0042] 5) Reduced risk of air leakage: Due to the complementary design of the current collection net and the pressure gauge platform gasket with the shape of the sealing cavity, it is easy to achieve sealing during testing, thereby reducing the possibility of air leakage and increasing the stability and reliability of the testing.

[0043] 6) Structural stability: Components such as sealed bolts and fixing nuts ensure the structural stability and durability of the entire testing device under high temperatures and various working conditions.

[0044] The above-mentioned technological advancements demonstrate a significant improvement in the accuracy, reliability, and operational convenience of the fuel cell performance testing of this testing device. These advancements can help researchers and engineers better understand and optimize the working mechanism and durability of solid oxide fuel cells, which is of great significance for the development of fuel cell technology. Brief Description of the Drawings

[0045] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments of the present invention. Obviously, the following described drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1 It is a schematic structural diagram of the testing system of the button solid oxide fuel cell testing device in the present invention; where: 1. Sealed bolt; 2. Inlet pipe; 3. Outlet pipe; 4. Upper fixing flange; 5. Cathode inlet chamber sealing sheet; 6. Cathode inlet chamber flow dividing partition; 7. Cathode side fixture; 8. Cathode side current collecting column; 9. Pressure gauge platform gasket; 10. Piezoelectric effect material of the pressure gauge; 11. Protection shell of the piezoelectric effect material of the pressure gauge; 12. Current transmission wire of the pressure gauge; 13. Anode side current collecting column; 14. Conduction column hole of the pressure gauge; 15. Anode side fixture; 16. Current collecting column hole of the anode side current collector; 17. Anode inlet chamber flow dividing partition; 18. Anode inlet chamber sealing sheet; 19. Lower fixing flange; 20. Fixing nut.

[0047] As Figure 2 It is an assembly schematic diagram, where 21. Solid oxide fuel cell testing current collecting piezoelectric effect inductor; 22. Foam nickel current collecting mesh; 23. Button solid oxide fuel cell; 24. Silver mesh current collecting mesh. Detailed Embodiments

[0048] In order to make the objectives, technical solutions, and advantages of the present invention clearer, the following further details the present invention in combination with embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0049] Aiming at the problems existing in the prior art, the present invention provides a solid oxide fuel cell testing device, which will be described in detail below in combination with the drawings.

[0050] The button solid oxide fuel cell test device provided by the present invention is a special design for testing the electrical performance and thermal expansion stress of a solid oxide fuel cell (SOFC) during operation.

[0051] Sealing and support structure:

[0052] The sealing bolt 1 and the fixing nut 20 are used to tightly connect the upper fixing flange 4 and the lower fixing flange 19 to form a stable structure.

[0053] The cathode-side fixture 7 and the anode-side fixture 15 are used to clamp the button solid oxide fuel cell 23 and ensure its good contact with the nickel foam current collector grid 22 and the silver mesh current collector grid 24.

[0054] Gas flow:

[0055] The inlet pipe 2 and the outlet pipe 3 are connected to the cathode inlet chamber and the anode inlet chamber to supply oxygen and fuel gas (usually hydrogen) and allow exhaust.

[0056] Current collection and testing:

[0057] The cathode-side current collector post 8 and the anode-side current collector post 13 are in contact with the corresponding nickel foam current collector grid 22 and silver mesh current collector grid 24, and the latter are in close contact with the corresponding cathode and anode surfaces of the button solid oxide fuel cell 23.

[0058] The pressure gauge platform gasket 9 is located above the button solid oxide fuel cell 23 to evenly distribute the pressure from the piezoelectric effect material 10 of the pressure gauge.

[0059] The detailed working principle of the present invention is as follows:

[0060] 1 Current collection and current output:

[0061] When the fuel cell 23 is in operation, the cathode-side current collector posts 8, 13 collect current from the two poles of the battery through the nickel foam current collector grid 22 and the silver mesh current collector grid 24. The silver mesh current collector grid 24 can effectively reduce the contact resistance due to the good electrical conductivity of silver, ensuring the effective output of current.

[0062] 2 Pressure testing:

[0063] The piezoelectric effect material 10 of the pressure gauge is located above the button solid oxide fuel cell 23, and its two sides are connected to the measuring device through the current transmission wire 12 of the pressure gauge.

[0064] During the operation of the battery, the pressure gauge platform gasket 9 bears the pressure caused by thermal expansion and transmits it to the piezoelectric effect material 10, which converts the pressure into an electrical signal for monitoring the thermal expansion stress of the battery.

[0065] 3 Sealing and heat insulation:

[0066] The cathode inlet chamber sealing sheet 5 and the anode inlet chamber sealing sheet 18 ensure that gas does not leak during the test, and at the same time play a role in heat insulation to ensure the accuracy of the test.

[0067] The cathode inlet chamber flow dividing partition plate 6 and the anode inlet chamber flow dividing partition plate 17 play a role in guiding the gas flow in the cathode and anode inlet chambers of the battery to ensure uniform gas distribution.

[0068] Through the coordinated work of the above components, the device can test the electrical performance and thermal stress of the button solid oxide fuel cell under simulated actual working conditions, providing important data for the design optimization of SOFC.

[0069] As Figure 1 shown, the solid oxide fuel cell test current collecting piezoelectric effect inductor provided by the embodiment of the present invention, the solid oxide fuel cell is a button battery, and the effective area of the battery is 2 - 5 cm 2 or so. The test fixture is mainly used to load the solid oxide fuel cell, and at the same time has the functions of current collection, controlling the installation and sealing pressure, and measuring the thermal expansion stress. During implementation, the device includes: a high-temperature tube furnace, an electrochemical workstation, a computer, and a solid oxide fuel cell test current collecting piezoelectric effect inductor 21 which is used in combination with a nickel foam current collecting mesh 22, a button solid oxide fuel cell 23, and a silver mesh current collecting mesh 24.

[0070] For the equipment and its components of the "solid oxide fuel cell test current collecting piezoelectric effect inductor", we can describe the following detailed connection relationships:

[0071] High-temperature tube furnace: Provides the required working temperature environment for the entire device. There should be enough space inside the furnace chamber to accommodate the solid oxide fuel cell and its test fixture.

[0072] Electrochemical workstation: Connected to the computer, used to control the charge and discharge process of the battery and collect relevant electrochemical data.

[0073] Computer: Controls and monitors the entire test process. It is connected to the electrochemical workstation and can display and store the performance parameters of the battery under different operating conditions in real time.

[0074] Solid oxide fuel cell test current collecting piezoelectric effect inductor 21: This inductor is located on one side of the solid oxide fuel cell and is in close contact with the nickel foam current collecting mesh 22. The function of this inductor is to detect and record the piezoelectric effect caused by current collection during the operation of the battery.

[0075] Nickel foam current collector net 22: Located on one side of the button solid oxide fuel cell 23, it forms a clamping state between the piezoelectric effect inductor 21 and the button cell 23. The nickel foam current collector net is responsible for collecting current from the battery and transmitting it to the external circuit.

[0076] Button solid oxide fuel cell 23: The main body part of the cell, which is clamped between the nickel foam current collector net 22 and the silver mesh current collector net 24.

[0077] Silver mesh current collector net 24: Located on the other side of the button solid oxide fuel cell 23, it is connected to the positive / negative electrode of the cell and is responsible for collecting or providing current from the cell.

[0078] During operation, the high-temperature tube furnace provides a constant working temperature for the cell. The solid oxide fuel cell is clamped between the nickel foam current collector net and the silver mesh current collector net. When the cell is working, current flows from one current collector net to the other, passing through the piezoelectric effect inductor at the same time. Thus, the inductor can measure the piezoelectric effect inside the cell caused by the current flow in real time. All electrochemical data, such as the voltage, current, and internal piezoelectric effect of the cell, can be recorded in real time by the electrochemical workstation and displayed on the computer.

[0079] As Figure 2 Shown in the assembly schematic diagram, the solid oxide fuel cell test current collector piezoelectric effect inductor 21 involved in the present invention is composed of a silver mesh nickel foam current collector net 22, a button solid oxide fuel cell 23, and a nickel foam silver mesh current collector net 24 when in use.

[0080] The current collector column contacts the current collector net to form a four-terminal connection method. The advantages of using the four-terminal connection method: The four-terminal connection method is an effective method to eliminate the wiring resistance and contact resistance for low-resistance measurement, thus ensuring the authenticity of the performance data of the solid oxide fuel cell during detection.

[0081] The experiment is divided into five steps: button fuel cell assembly, airtightness detection, temperature-thermal expansion stress detection, cell performance detection, and disassembly. The specific implementation process is as follows:

[0082] Coat the surface of the current collector net with conductive paste, and then attach the current collector net to the surface of the solid oxide fuel cell. The size of the cell and the current collector net matches the empty slot of the fixture.

[0083] Place the solid oxide fuel cell with the attached current collector net in the empty slot of the fixture. The empty position without the current collector net contacts the pressure gauge platform gasket 9, and the position with the current collector net contacts the current collector column.

[0084] After placing the cell, apply insulating sealant to the edge of the cell on the side without the pressure gauge for sealing to prevent the air and fuel gas on both the cathode and anode sides of the cell from directly contacting.

[0085] After coating, the upper and lower parts of the fixture are assembled. The upper and lower parts of the fixture are preliminarily fixed using a fixed flange in combination with fixing bolts and nuts. Then, sealant is applied to the edge of the fixture to prevent gas leakage.

[0086] The pressure gauge is connected to the signal acquisition and amplification processor and the computer installed with data acquisition and processing software using a communication interface and data cable, and the pressure gauge is debugged.

[0087] After connecting the pressure gauge, pressure is applied to the fixed flange using fixing bolts and nuts. At the same time, the change in the pressure gauge value is observed. When the pressure gauge value reaches 5% of the observable range, the pressure application is stopped.

[0088] A current collector is connected to the electrochemical workstation using a high-temperature resistant wire, such as a silver wire.

[0089] The high-temperature tube furnace is connected to the computer, and the furnace temperature increase is controlled using a programmed temperature rise.

[0090] The assembled fixture is placed in the high-temperature tube furnace, heated up and kept warm to cure the sealant. During this period, it is observed whether there is any change in the pressure gauge. When there is no change in the pressure gauge, it is considered that the test is not affected by the sealant.

[0091] After the sealant is cured, nitrogen is introduced into the inlet pipe for airtightness detection.

[0092] After the airtightness test is passed, heating is started to measure the thermal expansion stress of the solid oxide fuel cell. The expansion deformation of the battery material is conducted through the conduction column of the pressure gauge to the piezoelectric material to output voltage, and the computer will collect the current signal and convert it into the expansion deformation of the battery material.

[0093] When performing battery performance detection, the data connection cable of the pressure gauge can be disconnected, air and fuel gas are introduced, and the furnace temperature is controlled in combination with the electrochemical workstation to perform battery performance detection.

[0094] After all detections are completed, wait for the furnace temperature of the tube furnace to drop, disassemble and tidy up the assembled fixture, and the detection is over.

[0095] The embodiments of the present invention have achieved some positive effects during the research and development or use process, and indeed have great advantages compared with the prior art. The thickness of a single solid oxide fuel cell is generally between 1 mm and 3 mm, and theoretically its volume expansion rate is generally between 0.1% and 0.5%. This deformation range is very small, so it is very difficult to accurately measure. Currently, dilatometers and X-ray diffraction methods are generally used for measurement, which are costly and require a large amount of samples or require pretreatment of the samples. Compared with the current solid oxide fuel cell test devices, the advantages of the present invention are as follows: the device is internally provided with a high-temperature resistant piezoelectric induction component as a pressure measuring device, isolating the interference of external factors; secondly, the expansion component is in close contact with the test component, ensuring the authenticity of the expansion stress; finally, in the current collecting part, the current collecting column of the device of the present invention is fixed inside the fixture, avoiding repeated disassembly of the diversion connection column during the battery assembly process and reducing the operation steps.

[0096] Example 1: High-temperature test of a solid oxide fuel cell

[0097] 1) Preparation stage

[0098] Select a button-type solid oxide fuel cell with an effective area of about 2 - 5 cm^2.

[0099] Fix the battery at its predetermined position using the fixing flange of the current collecting high-temperature piezoelectric sensor.

[0100] Connect oxygen and methane or other fuel gases to the gas supply ports of the intake cavity.

[0101] 2) Test stage

[0102] Open the high-temperature tubular furnace and gradually heat up to 800 °C.

[0103] Adjust the flow rates of oxygen and fuel gases in the intake cavity through the electronic control valve, and monitor them in real time through the flow meter and pressure sensor.

[0104] Start the discharge test of the battery through the electrochemical workstation, and at the same time export the generated current using the current collecting column.

[0105] Use a pressure gauge to monitor the thermal expansion force of the battery in real time, and transmit the data to the computer for recording and analysis.

[0106] 3) Analysis stage

[0107] Analyze the discharge performance of the solid oxide fuel cell based on the data collected by the electrochemical workstation.

[0108] Analyze the thermal expansion characteristics of the battery and the relationship between them and the discharge performance based on the data provided by the pressure gauge.

[0109] Example 2: Long-term Stability Test of Solid Oxide Fuel Cell

[0110] 1) Preparation Stage

[0111] Select a button-type solid oxide fuel cell with an effective area of about 2 - 5 cm².

[0112] Fix the cell in its predetermined position using the fixed flange of the current collector high-temperature piezoelectric sensor.

[0113] Connect oxygen and hydrogen to the gas supply ports of the intake chamber.

[0114] 2) Testing Stage

[0115] Open the high-temperature tube furnace and gradually heat up to 750 °C.

[0116] Regulate the oxygen and hydrogen flow rates in the intake chamber through the electronic control valve to maintain constant gas supply conditions.

[0117] Discharge the cell continuously through the electrochemical workstation for a duration of 100 hours.

[0118] Use a pressure gauge to monitor the thermal expansion force of the cell in real-time and transmit the data to a computer for recording.

[0119] 3) Analysis Stage

[0120] Based on the data collected by the electrochemical workstation, analyze the performance degradation of the solid oxide fuel cell under long-term operation.

[0121] Based on the data provided by the pressure gauge, analyze the thermal expansion characteristics of the cell and their changes, and compare with the performance degradation data to understand the possible causes and mechanisms.

[0122] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent replacement, and improvement made by those skilled in the art within the technical scope disclosed by the present invention, as long as they are made within the spirit and principle of the present invention, shall be covered by the protection scope of the present invention.

Claims

1. A current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing, characterized in that, Comprising: A fixed flange for fixing the test fixture of a solid oxide fuel cell; An intake chamber connected to the fixed flange, for supplying oxygen and fuel gas and having a pressure maintaining function; A fixture composed of upper and lower parts, closely cooperating with the fixed flange, for clamping and assembling a solid oxide fuel cell; Current collector posts arranged inside the fixture, contacting the electrodes of the solid oxide fuel cell, for leading out the current generated by the electrodes; A pressure gauge arranged on one side of the fixture, contacting the solid oxide fuel cell, for real-time collecting the thermal expansion force of the solid oxide fuel cell under high-temperature working conditions; The said fixed flange comprises: The flange is divided into upper and lower parts, drilled according to the positions of the inlet and outlet pipes, with the hole diameter matching the diameter of the gas transmission pipe, allowing the gas pipe to pass through; drilled for fixing bolts, for assembly fixing and pressurization; The said intake chamber comprises: The intake chamber is composed of upper and lower parts, consisting of an inlet pipe, an outlet pipe, a flow dividing partition plate and a sealing sheet. There are holes on the fixture. The flow dividing partition plate and the outlet pipe extend into the fixture. The inlet pipe is arranged on the sealing sheet. The sealing sheet seals the holes on the fixture to form a complete intake chamber. The inlet pipe is used to introduce air or fuel gas into the fixture to contact the surface of the battery electrode. The flow dividing partition plate is used for pressure maintaining and guiding the reacted gas to the outlet pipe. The sealing sheet is used for sealing; The said pressure gauge comprises: The pressure gauge is composed of a platform gasket, a conduction pillar, a piezoelectric effect material, a signal acquisition and amplification processor, a communication interface and a data line, and data acquisition and processing software. The platform gasket is in close contact with the battery surface and connected to the conduction pillar. The conduction pillar conducts the expansion stress of the battery to the piezoelectric effect material. The weak current generated by the piezoelectric effect material under pressure is received by the signal acquisition and amplification processor and subjected to noise reduction processing, and is uploaded to the data acquisition and processing software on the computer side through the communication interface and the data line.

2. The current collector high-temperature piezoelectric sensor according to claim 1, characterized in that, There are multiple gas supply ports in the said intake chamber, respectively used for inputting oxygen and fuel gas, and the intake chamber is provided with valves to achieve precise control of the gas flow rate and pressure.

3. The current collector high-temperature piezoelectric sensor according to claim 1, characterized in that, The interior of the said pressure gauge uses a piezoelectric material with high temperature stability and has a design matching the thermal expansion coefficient of the solid oxide fuel cell to ensure precise pressure measurement under high-temperature working conditions and avoid errors caused by thermal stress.

4. The current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing according to claim 1, characterized in that, The said fixture comprises: The fixture is divided into upper and lower parts, made of an insulating material with a low thermal expansion rate, drilled according to the positions of the current collector posts and the pressure gauge, for loading the battery and installing the current collector posts and the pressure gauge.

5. The current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing according to claim 1, characterized in that, The said current collector posts comprise: The current collector posts are four high-conductivity materials with a low thermal expansion rate, contacting the current collecting network on the electrode surface, for leading out the current, and can be replaced when the material fails.

6. The current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing according to claim 1, characterized in that, The said platform gasket and conduction pillar are made of an insulating material with an extremely low thermal expansion rate; The said piezoelectric effect material maintains volume stability within the range of 300 - 1000 °C and can generate a high normalized output voltage.

7. Application of the current collector high-temperature piezoelectric sensor for solid oxide fuel cell testing according to any one of claims 1 to 6 in the process of solid oxide fuel cell testing.

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