Electrochemical performance testing device and application

Abstract

The application discloses an electrochemical performance testing device and application, relates to the solid oxide fuel cell technical field, and the electrochemical performance testing device includes single cell clamp, the single cell to be measured, electrochemical performance testing components and temperature control and gas control components; the single cell clamp includes ceramic tube one and ceramic tube two which are arranged in a sleeve shape and fixing pieces; the ceramic tube one is a gas inlet pipeline, the outer diameter of the ceramic tube one is smaller than the inner diameter of the ceramic tube two, and the gap between the ceramic tube one and the ceramic tube two is a gas outlet pipeline; the fixing pieces clamp and fix the ceramic tube one; the single cell to be measured fixes one end of the sealed ceramic tube two; the single cell to be measured and the electrochemical performance testing components form a loop through the lead wire passing through the ceramic tube one; the temperature control and gas control components are used for adjusting the temperature of test gas and driving test gas into the gas inlet pipeline.The device is easy to assemble, has good air tightness, avoids gas leakage of the single cell during the testing process, and guarantees the accuracy and safety of the testing result.

Description

Technical Field

[0001] This invention relates to the field of solid oxide fuel cell technology, and more specifically to an electrochemical performance testing device and its application. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are devices that directly convert the chemical energy of raw materials (hydrogen, oxygen, etc.) into electrical energy at operating temperatures of 500-1000℃. They have advantages such as high power generation efficiency, low environmental pollution, and ease of construction. They can power large vehicles, ships, and distributed power stations and are an important component of the hydrogen energy economy industrial chain.

[0003] Solid oxide fuel cells (SOFCs) mainly consist of an electrolyte, an anode, a cathode, and connecting materials. They typically have a sandwich structure consisting of two porous electrodes (cathode and anode) combined with a dense electrolyte. The anode is a support made of a mechanical mixture of nickel oxide and electrolyte ceramic powder, with an electrolyte film covering the surface of the anode support. The cathode is a porous perovskite material coating. In existing technologies, the anode and cathode are usually connected by test leads, which are then sealed to a ceramic tube open at both ends using ceramic adhesive. However, this method suffers from drawbacks such as poor sealing, easy leakage, and high risk.

[0004] Chinese patent document CN204008857U discloses a device for testing the impedance of a cathode symmetrical cell in a solid oxide fuel cell. The device includes a cathode symmetrical cell assembly, a ceramic tube, silver wires, and a ceramic electrolyte sheet. This invention improves working efficiency and accurately measures polarization impedance by setting a specific arrangement of silver wires and fixing the ceramic tube with iron wires. It also reduces damage caused by unevenness of the symmetrical cell during the measurement process. However, this device tests the performance of the symmetrical cell and does not require airtightness.

[0005] Chinese patent document CN110531273A discloses a high-temperature fuel cell testing system. The high-temperature fuel cells include molten carbonate fuel cells and solid oxide fuel cells, among others. The testing system includes a fuel cell stack, a gas control device, and multiple gas cylinders. The outlet of each gas cylinder is connected to both the anode and cathode inlets of the fuel cell stack. A gas control device is installed on the connecting pipe of each gas cylinder's outlet. This invention can be used to test various high-temperature fuel cells, solving the problem of poor universality in existing fuel cell testing systems. It has a simple structure and is easy to implement. However, the testing accuracy of this device needs further investigation. Summary of the Invention

[0006] This invention provides an electrochemical performance testing device that can be used to test the electrochemical performance of solid oxide fuel cell or solid oxide fuel cell electrode materials. The device has all wires built-in, is easy to assemble, has good airtightness, avoids leakage of the single cell during the test, and ensures the accuracy and safety of the test results.

[0007] The specific technical solution adopted is as follows:

[0008] An electrochemical performance testing device includes: a single-cell clamp, a single-cell under test, an electrochemical performance testing component, and a temperature and gas control component;

[0009] The single-cell clamp includes a first ceramic tube and a second ceramic tube arranged in a sleeve shape, as well as a fixing component; the first ceramic tube is the air inlet pipe, the outer diameter of the first ceramic tube is smaller than the inner diameter of the second ceramic tube, and the gap between the first ceramic tube and the second ceramic tube is the air outlet pipe; the fixing component clamps and fixes the first ceramic tube.

[0010] The single cell under test is fixed and sealed at one end of the ceramic tube 2. The single cell under test and the electrochemical performance testing component form a circuit through the wire passing through the ceramic tube 1.

[0011] The temperature and gas control components are used to regulate the temperature of the test gas and drive the test gas into the inlet pipe.

[0012] The device of this invention is used to test the electrochemical performance of solid oxide fuel cell or solid oxide fuel cell electrode materials.

[0013] In existing small-scale solid oxide fuel cell electrochemical performance testing devices, there are gaps between the wires and the ceramic binder. Under high temperature (>500℃) conditions, the thermal expansion coefficients of the wires and ceramics differ significantly, which causes hydrogen gas inside the ceramic tube to easily leak out from the connection point, thus affecting the accuracy and safety of the test. This invention improves the airtightness of the device by designing the single-cell clamp and the wire arrangement, avoiding battery leakage during testing, reducing battery operation risks, and ensuring good test safety and high accuracy.

[0014] Preferably, the single-cell clamp also includes an internal wire, one end of which is spring-shaped and used to press against the single cell under test, while the other end extends out from an opening in the ceramic tube. The spring portion improves the stability of the circuit.

[0015] Preferably, the wire is made of silver, and the ceramic tubes one and two are made of aluminum oxide. The single cell under test is fixed and sealed at the opening of the ceramic tube two by a ceramic adhesive.

[0016] In a further preferred embodiment, the single-cell clamp also includes a ceramic tube three, which is sealed and fitted onto the outer surface of the ceramic tube two to clamp the single-cell under test.

[0017] The single cell under test is a sandwich-structured disc, consisting of an anode plate, an electrolyte film, and a cathode plate stacked from bottom to top. The sandwich structure of the single cell under test offers better compatibility.

[0018] Electrochemical performance testing components are used to test the open-circuit voltage, output power, or ohmic impedance of a single cell under test.

[0019] Preferably, the temperature and gas control component introduces the test gas into the inlet of ceramic tube one, and the test gas is discharged through the gap between ceramic tube one and ceramic tube two after contacting the electrode of the single cell under test.

[0020] Preferably, the test gas is hydrogen gas at a temperature of 500-1000℃. After the test gas reacts with the anode plate of the single cell under test, it is discharged through the gap between ceramic tube one and ceramic tube two.

[0021] The present invention also provides a method for testing the electrochemical performance of electrode materials for solid oxide fuel cell single cells using the aforementioned device, comprising the following steps:

[0022] (1) The single cell to be tested was prepared using the electrode material to be tested;

[0023] (2) The single cell to be tested is sealed and fixed at the opening of the second ceramic tube, and the wire is connected. The test gas is introduced into the opening of the first ceramic tube using the temperature and gas control components. After the test gas comes into contact with the single cell to be tested, it is discharged through the gap between the first and second ceramic tubes. The performance of the electrode material is tested based on the parameters obtained by the electrochemical performance testing components.

[0024] The preferred method for preparing the single cell to be tested is as follows:

[0025] (1-1) The electrode material to be tested is made into an anode slurry, and then the anode slurry is made into an anode single cell substrate by calcination.

[0026] (2-1) The electrolyte solution was coated onto the anode single cell substrate by drop coating, and then dried and sintered to obtain the electrolyte-anode single cell substrate.

[0027] (3-1) The single cell to be tested is obtained by coating the cathode slurry onto the electrolyte-anode single cell substrate, drying it and then calcining it.

[0028] Alternatively, (1-2) the anode slurry is prepared into an anode single cell substrate by calcination;

[0029] (2-2) The electrolyte solution was coated onto the anode single cell substrate by drop coating, and then dried and sintered to obtain the electrolyte-anode single cell substrate.

[0030] (3-2) The electrode material to be tested is made into a cathode slurry, which is then coated onto an electrolyte-anode single cell substrate. After drying, the substrate is further calcined to obtain the single cell to be tested.

[0031] This invention uses a drop-coating method to uniformly cover the electrolyte onto the surface of the anode substrate. During the drop-coating process, the electrolyte solution extends into a film based on the surface tension of the liquid. The resulting electrolyte layer is uniform and dense in thickness after sintering, and the thickness is controllable, with a minimum of 15-20 μm. That is, using the single cell prepared by the above drop-coating method, combined with the testing device of this invention, it is possible to accurately test the electrochemical performance of solid oxide fuel cell single cells, and thus accurately evaluate the electrochemical performance of the cathode or anode materials.

[0032] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0033] (1) By designing a single-cell clamp and wire arrangement, this invention improves the airtightness of the device, avoids battery leakage during testing, reduces battery operation risk, and ensures good testing safety and high accuracy.

[0034] (2) The present invention prepares electrolyte films by drop coating, which can be completed at room temperature, normal pressure and air, and is easy to implement. After further calcination, the electrolyte layer of the single cell is uniform and dense. The single cell is well compatible with the device of the present invention. After the two are assembled, the electrochemical performance of solid oxide fuel cell can be accurately tested. The open circuit voltage of the single cell caused by the pressure difference of the gas flow at the anode and cathode ends does not change significantly over time, and the test stability is excellent. The method of the present invention can be used to accurately evaluate the performance of the cathode material or anode material. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the electrochemical performance testing device.

[0036] Figure 2 This is a schematic diagram of the structure of the single cell under test.

[0037] Figure 3 This is a SEM image of the cross-section of the single cell under test in Example 1.

[0038] Figure 4 The curve of the battery open-circuit voltage changing over time in Example 1 is shown.

[0039] Figure 5 The cathode material PrBaCo2O in Example 1 5+δ Electrochemical performance test diagrams of solid oxide fuel cell prepared by further processing of -0.1BiFeO3, where A is the ohmic impedance diagram of the single cell at 500-650℃ and B is the output power curve of the single cell at 500-650℃.

[0040] Figure reference numerals: 1—Single cell under test, 2—Single cell clamp, 3—Electrochemical performance testing component, 4—Temperature and gas control component; 10—Wire 1, 11—Anode plate, 12—Electrolyte film, 13—Cathode plate, 14—Wire 2; 20—Internal wire, 21—Ceramic tube 1, 22—Ceramic tube 2, 23—Ceramic tube 3, 24—Fixing component. Detailed Implementation

[0041] The present invention will be further illustrated below with reference to the embodiments and accompanying drawings. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0042] An apparatus for testing the electrochemical performance of solid oxide fuel cell single cells, the apparatus as follows: Figure 1 As shown, it includes: a single-cell clamp 2, and a single-cell battery to be tested 1. Figure 2 ), electrochemical performance testing component 3, temperature and gas control component 4;

[0043] The single-cell clamp 2 includes a first ceramic tube 21 and a second ceramic tube 22 arranged in a sleeve shape, a fixing member 24, and an internal wire 20. The first ceramic tube 21 is an air inlet pipe, the outer diameter of the first ceramic tube is smaller than the inner diameter of the second ceramic tube, and the gap between the first ceramic tube 21 and the second ceramic tube 22 is an air outlet pipe. The fixing member 24 clamps and fixes the first ceramic tube 21. One end of the internal wire 20 is spring-shaped and used to push against the single cell 1 to be tested, and the other end passes through the opening of the first ceramic tube 21. The single-cell clamp 2 also includes a third ceramic tube 23, which is sealed and sleeved on the outer surface of the second ceramic tube 22 to clamp the single cell 1 to be tested.

[0044] The test cell 1 is fixed and sealed at the opening of the ceramic tube 2. The electrode of the test cell 1 is connected to the wire 10 and the wire 24. The wire 10 is connected to the internal wire 20 and then passes through the ceramic tube 21 (a seal is provided at the outlet to ensure the airtightness of the device). It is connected to the electrochemical performance testing component 3 together with the wire 24 to form a circuit.

[0045] The temperature and gas control component 4 is used to adjust the temperature of the test gas and drive the test gas into the inlet pipe. The test gas is introduced into the port of ceramic tube 1 using the gas valve. After the test gas comes into contact with the electrode of the single cell under test, it is discharged through the gap between ceramic tube 1 21 and ceramic tube 2 22.

[0046] Example 1

[0047] Preparation of the single cell to be tested:

[0048] (1) With Sm 0.20 Ce 0.80 O 1.95Using SDC, NiO powder and potato starch as raw materials, ethanol as the ball milling dispersion liquid and zirconia balls as the grinding medium, the mixture was ball milled and mixed to obtain a slurry; the slurry was dried and pressed into 0.3g discs with a diameter of 13 mm, and sintered in a muffle furnace at 800℃ for 4 hours to obtain an anode single cell substrate;

[0049] (2) A blank electrolyte solution was prepared using methyl ethyl ketone, ethanol, triethanolamine, polyethylene oxide polypropylene oxide monobutyl ether, toluene butyl phthalate and polyvinyl butyral; the blank electrolyte solution was thoroughly ultrasonically mixed with SDC powder to obtain a mixed electrolyte solution; then an electrolyte layer was prepared by drop coating method, the specific steps of which included: using a pipette to drop the first part of the mixed electrolyte solution onto the anode single cell substrate, and after it was dried in air at room temperature, the second part of the mixed electrolyte solution was dropped onto it using a pipette, and after the surface solution was dried again, it was placed in a muffle furnace and sintered in air at 1400°C to obtain the electrolyte-anode single cell substrate.

[0050] (3) The cathode material PrBaCo2O 5+δ -0.1BiFeO3 (δ represents the oxygen defect number) was thoroughly mixed with cathode slurry binder V600 to obtain a cathode slurry. A mask with a 5 mm circular hole was used to cover the circumference of the electrolyte-anode single-cell substrate, aligning the center of the hole with the center of the substrate. The cathode slurry was then applied to the substrate, dried at room temperature, and calcined in a muffle furnace at 950°C for 1 hour to prepare the single cell to be tested. A cross-sectional SEM image of the single cell is shown below. Figure 3 As shown, the anode has a porous structure, the electrolyte film is dense with a thickness of about 15 μm, and the cathode has a porous structure.

[0051] (4) Cut two 10 cm long, 0.3 mm thick pure silver wires, preferably twist them into a circle with a diameter of 0.3-0.4 cm, and then contact them with the cathode and anode of the single cell respectively. Then use silver glue to fix them in the center of the cathode and anode of the single cell to be tested. Dry them in the air for 5 hours to obtain the single cell to be tested.

[0052] Testing process

[0053] The anode of the single cell to be tested is fixed and sealed at the opening of the second ceramic tube by the action of ceramic adhesive. At the same time, the anode wire of the single cell to be tested is connected to the spring-shaped internal wire in the single cell fixture (the spring-shaped internal wire acts as a push against the single cell to be tested). The internal wire passes through the first ceramic tube and is connected to the electrochemical performance testing component together with the second wire.

[0054] Turn on the temperature and gas control components and introduce hydrogen gas into the opening of ceramic tube one. After the test gas comes into contact with the anode of the single cell under test, it is discharged through the gap between ceramic tube one (21) and ceramic tube two (22) and enters the gas recovery device. The program of the temperature and gas control components is set as follows: heat up from room temperature at 1℃ / min to 93℃, hold at 3 hours, then heat up from 93℃ to 260℃ at a rate of 1℃ / min, hold at 260℃ for 3 hours, then heat up from 260℃ to 700℃ at a rate of 2℃ / min, and hold at 700℃ for 1 hour before testing the electrochemical performance of the single cell.

[0055] like Figure 4 As shown, the solid oxide fuel cell under test exhibits excellent airtightness in the test device, and its open circuit voltage (OCV) caused by the pressure difference between the anode and cathode ends does not decrease significantly over time.

[0056] The electrochemical performance test results of the solid oxide fuel cell are shown in the figure below. Figure 5 As shown, A is the ohmic impedance diagram of a single cell at 500-650℃, and B is the output power curve of a single cell at 500-650℃.

[0057] Example 2

[0058] The battery preparation method in this embodiment is the same as in Embodiment 1, except that the anode material is changed from Sm 0.20 Ce 0.80 O 1.95 (SDC) replaced with BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ In the preparation of the anode single cell substrate, (BZCYYb) was prepared using BZCYYb and NiO powder as raw materials, ethanol as the ball milling dispersion liquid, and zirconia balls as the grinding medium. The mixture was ball milled and mixed to obtain a slurry; the remaining operations remained unchanged.

[0059] The testing method in this embodiment is the same as the testing method in Embodiment 1.

[0060] The above embodiments provide a detailed description of the technical solution of the present invention. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, additions, or similar substitutions made within the scope of the principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electrochemical performance testing device, characterized by, The device comprises a single cell clamp (2), a single cell to be tested (1), an electrochemical performance testing component (3) and a temperature and gas control component (4). The single cell clamp (2) comprises a ceramic tube I (21) and a ceramic tube II (22) arranged in a sleeve shape and a fixing member (24); the ceramic tube I (21) is an air inlet pipe, the outer diameter of the ceramic tube I is smaller than the inner diameter of the ceramic tube II, and the gap between the ceramic tube I (21) and the ceramic tube II (22) is an air outlet pipe; the fixing member (24) clamps and fixes the ceramic tube I (21); The single cell to be tested (1) is fixed and sealed to one end of the ceramic tube II (22), and the single cell to be tested (1) and the electrochemical performance testing component (3) form a loop through the lead wire passing through the ceramic tube I (21); The temperature and gas control component (4) is used for adjusting the temperature of the test gas and driving the test gas into the air inlet pipe; The single cell clamp (2) further comprises an internal lead wire (20), one end of which is in a spring shape and used for abutting against the single cell to be tested (1), and the other end of which passes out through the ceramic tube I (21); The single cell clamp (2) further comprises a ceramic tube III (23) which is sealed and sleeved on the outer surface of the ceramic tube II (22) and used for clamping the single cell to be tested (1); The single cell to be tested (1) is a round sheet with a sandwich structure, which is formed by stacking an anode sheet (11), an electrolyte film (12) and a cathode sheet (13) from bottom to top; The test gas is hydrogen with a temperature of 500-1000℃, which is discharged through the gap between the ceramic tube I (21) and the ceramic tube II (22) after contacting and reacting with the anode sheet of the single cell to be tested; The electrochemical performance testing component (3) is used for testing the open circuit voltage, output power or ohmic impedance of the single cell to be tested; The electrochemical performance testing device is used for testing the electrochemical performance of a solid oxide fuel single cell or a solid oxide fuel single cell electrode material. The material of the ceramic tube I (21) and the ceramic tube II (22) is alumina, and the single cell to be tested (1) is fixed and sealed at the ceramic tube II pipe opening by a ceramic adhesive.

2. The electrochemical performance testing device of claim 1, wherein, The temperature and gas control component (4) passes the test gas into the ceramic tube I pipe opening, and the test gas is discharged through the gap between the ceramic tube I (21) and the ceramic tube II (22) after contacting the electrode of the single cell to be tested.

3. The electrochemical performance testing apparatus of claim 1, wherein, 4. Use of the device according to any one of claims 1-3 for testing the electrochemical performance of a solid oxide fuel single cell or a solid oxide fuel single cell electrode material. The steps for testing the electrochemical performance of a solid oxide fuel single cell electrode material comprise the following steps:

5. Use according to claim 4, characterized in that, (1) preparing the single cell to be tested (1) by using the electrode material to be tested; (2) sealing and fixing the single cell to be tested (1) at the ceramic tube II pipe opening, connecting the lead wire, passing the test gas into the ceramic tube I pipe opening by using the temperature and gas control component (4), discharging the test gas through the gap between the ceramic tube I (21) and the ceramic tube II (22) after contacting the single cell to be tested (1), and testing the performance of the electrode material according to the parameters obtained by the electrochemical performance testing component (3). The preparation method of the single cell to be tested comprises the following steps:

6. Use according to claim 5, characterized in that, (1-1) preparing anode slurry by using the electrode material to be tested, and preparing an anode single cell substrate by firing the anode slurry; ​ (2-1) electrolyte solution is coated on the anode single cell substrate by drop coating method, dried and further sintered to obtain electrolyte-anode single cell substrate; (3-1) the cathode slurry is coated on the electrolyte-anode single cell substrate, dried and further calcined to obtain the single cell (1) to be tested; or, (1-2) the anode slurry is prepared into an anode single cell substrate by calcination method; (2-2) electrolyte solution is coated on the anode single cell substrate by drop coating method, dried and further sintered to obtain electrolyte-anode single cell substrate; (3-2) the electrode material to be tested is prepared into a cathode slurry, the cathode slurry is coated on the electrolyte-anode single cell substrate, dried and further calcined to obtain the single cell (1) to be tested.

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