Atmosphere-controllable perovskite durability testing device

Abstract

The invention provides an atmosphere-controllable perovskite durability testing device, and relates to the technical field of poisoning resistance of oxygen electrode materials of solid oxide batteries. Comprising a gas cylinder, an atmosphere control unit, a detection unit and a signal collection unit which are connected in sequence, the gas cylinder is used for providing test gas, the atmosphere control unit is used for adjusting components and flow of the test gas according to preset test requirements and mixing the test gas with a built-in atmosphere volatilization source to live a target test environment, and the detection unit is used for collecting electric signals and impedance change data of a to-be-tested sample in the target test environment. And the signal collection unit is used for receiving and evaluating the electric signal and the impedance change data acquired by the detection unit to obtain a durability evaluation result. The method solves the problem that the evaluation of the performance of the oxygen electrode material is insufficient due to the limitation of the method for evaluating the durability of the perovskite material in the prior art and the incapability of comprehensively simulating the comprehensive influence of various factors in the real working environment of the electric pile.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of oxygen electrode material anti-poisoning of a solid oxide cell, and particularly relates to a perovskite durability test device with controllable atmosphere. BACKGROUND

[0002] Due to the increasingly serious problems such as shortage of traditional fossil fuel supply, strong demand for clean, reliable and sustainable energy has led to great attention and extensive research on electrochemical energy storage devices and energy conversion devices. The reversible solid oxide cell (RSOC) can convert chemical energy in fuel into electric energy for power generation, and can also convert electric energy generated by green energy into chemical energy for storage, and has the advantages of being clean, efficient and modular. The sustainable energy system constructed by alternating operation of the two modes has important significance for solving the energy and environmental problems faced by human beings. However, the long-term stability of the RSOC has become one of the important reasons restricting its commercial development. The solid oxide cell is usually composed of three parts: a porous fuel electrode, a porous oxygen electrode and a dense electrolyte layer. Generally, the porous fuel electrode of the cell is usually composed of a metal ceramic material, the porous oxygen electrode is usually composed of a perovskite material, and the electrolyte is usually composed of a dense Y-stabilized zirconia. In addition, in order to achieve the expected power, a plurality of single cells are usually connected in series into an electric pile through a connecting body, and a sealing material is applied to integrate the peripheral gas supply, heat management and control unit to form an electric pile system. Therefore, the connecting body and the sealing material are key components in the electric pile. Among various connecting body materials, the Cr-containing ferritic stainless steel has the advantages of matching the thermal expansion coefficient with the electrolyte material, forming a dense Cr2O3 oxide film to realize the oxidation resistance of the alloy, and the generated surface oxide layer has a certain conductivity at the working temperature, and has become a widely used connecting body material. However, in the high-temperature and high-humidity working environment, the Cr-containing oxide layer on the surface layer of the metal connecting body is unstable, and the following reaction occurs:

[0003] Cr2O3 (s) +3 / 2O2 → 2CrO3 (g) (1)

[0004] The metal connector releases volatile Cr species that deposit on the surface of the oxygen electrode and form a high resistance phase, resulting in irreversible performance degradation of the stack. The sealing material is usually made of alkaline earth silicate, borosilicate or barium aluminum silicate glass, which contains 20-70wt% of SiO2. The silicon-containing substances in the silicate-based sealing material can also be released under high temperature and high humidity working conditions, forming electrically insulating secondary phases and changing the local surface composition to affect the oxygen electrode material. The resulting degradation is similar to Cr poisoning. In addition, there is a significant interaction between CO2 and SO2 pollutants in the air and perovskite oxides, producing electrically insulating carbonates that cover the active sites on the surface of the oxygen electrode, blocking the adsorption and diffusion of oxygen, and thus causing irreversible performance degradation. Since the polarization loss of the battery system mainly comes from the oxygen electrode redox reaction, good durability in the working atmosphere is crucial for the long-term stable operation of the RSOC. Therefore, testing and evaluating perovskite materials with excellent durability for the oxygen electrode of the RSOC is crucial to maintain the stability of the electrochemical performance of the oxygen electrode. There are mainly two methods for evaluating the durability of perovskite materials: by preparing the oxygen electrode material to a half-cell and simulating the corresponding working atmosphere, measuring the change of the half-cell impedance with time, and characterizing the distribution and location of Cr deposition on the oxygen electrode of the half-cell after testing. The main problems of the above method are: (1) only single atmosphere or single factor can be tested to affect the durability of the oxygen electrode material; (2) it is impossible to simulate the influence of multiple factors on the oxygen electrode material in the real working environment of the stack. SUMMARY

[0005] In order to overcome the shortcomings of the prior art, the purpose of the present application is to provide an atmosphere-controllable perovskite durability test device. The present application solves the problem that the method for evaluating the durability of perovskite materials in the prior art has limitations and cannot comprehensively simulate the combined influence of multiple factors in the real working environment of the stack, resulting in insufficient evaluation of the performance of the oxygen electrode material.

[0006] To achieve the above purpose, the present application provides the following solutions:

[0007] An atmosphere-controllable perovskite durability test device comprises:

[0008] a gas cylinder, an atmosphere control unit, a detection unit and a signal collection unit connected in sequence;

[0009] The gas cylinder is used to provide test gas, the atmosphere control unit is used to adjust the composition and flow of the test gas according to preset test requirements and mix with the built-in atmosphere volatile source, the target test environment, the detection unit is used to collect the electrical signal and impedance change data of the sample to be tested in the target test environment, and the signal collection unit is used to receive the electrical signal and impedance change data collected by the detection unit and evaluate to obtain the durability evaluation result.

[0010] Preferably, the test gas comprises oxygen, nitrogen, hydrogen and water vapor.

[0011] Preferably, the atmosphere control unit comprises:

[0012] The first gas inlet path, the first three-way valve, the second gas inlet path, the U-shaped pipe, the atmosphere volatile source, the second three-way valve and the first gas outlet path and the second gas outlet path;

[0013] One end of the first gas inlet path is connected with the gas cylinder, the other end of the first gas inlet path is connected with the second gas inlet path and the second three-way valve through the first three-way valve, the atmosphere volatile source is built in the lowest end of the U-shaped pipe, the second gas inlet path is connected with the gas inlet port of the U-shaped pipe, one end of the first gas outlet path is connected with the gas outlet port of the U-shaped pipe, the other end of the first gas outlet path is connected with one end of the second gas outlet path through the second three-way valve, and the other end of the second gas outlet path is connected with the detection unit;

[0014] The first three-way valve is used to adjust the direction of the test gas, the second three-way valve is used to adjust the direction of the gas in the target test environment, and the atmosphere volatile source is used to volatilize various atmosphere gases.

[0015] Preferably, flow meters are arranged on the first gas inlet path, the second gas inlet path, the first gas outlet path and the second gas outlet path respectively.

[0016] Preferably, the detection unit and the atmosphere control unit are both tube furnaces.

[0017] Preferably, the sample to be tested is a perovskite electrode material and electrolyte supported half-cell structure.

[0018] Preferably, the material of the U-shaped pipe is quartz.

[0019] Preferably, the second gas outlet path is wrapped with a heat tracing band outside.

[0020] According to the specific embodiments of the present application, the following technical effects are provided:

[0021] The application provides a perovskite durability test device with controllable atmosphere, which comprises an atmosphere control unit, wherein an atmosphere volatilization source is arranged, different or multiple atmosphere volatilization sources can be placed to simulate different service environments. During the test, the atmosphere volatilization source is heated to volatilize special atmosphere (for example, gaseous Cr vapor, gaseous silicon-containing species, etc.), which is deposited on the surface of the sample to be tested and affects the impedance change of the sample to be tested. The changed impedance is recorded by a signal collection device, and the change of different impedance values with time corresponds to the durability of the perovskite material to be tested. As can be seen, the detection device can monitor the impedance value change of the sample to be tested by providing different gas sources and replacing the atmosphere volatilization source, and then quantifying the tolerance performance of the material under different atmospheres. The special atmosphere volatilization source can be accelerated to emit a large amount of special atmosphere, so that the accelerated experiment can be carried out, and the influence of different atmospheres or multiple atmospheres on the durability of the perovskite material can be accurately measured, so that the test result is closer to the real situation. BRIEF DESCRIPTION OF DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0023] Figure 1 A structure schematic diagram of a perovskite durability test device with controllable atmosphere provided by the embodiment of the present application is provided.

[0024] Figure 2 A structure schematic diagram of a solid-state electrolyte supported half-cell provided by the embodiment of the present application is provided.

[0025] Figure 3 A detailed schematic diagram of a perovskite durability test device with controllable atmosphere provided by the embodiment of the present application is provided.

[0026] Figure 4 A first test result schematic diagram of a perovskite material to be tested provided by the embodiment of the present application is provided.

[0027] Figure 5 A second test result schematic diagram of a perovskite material to be tested provided by the embodiment of the present application is provided.

[0028] Figure 6 An impedance growth rate schematic diagram provided by the embodiment of the present application is provided.

[0029] Explanation of reference signs:

[0030] 1-gas cylinder; 2-first gas inlet path; 3-first three-way valve; 4-second gas inlet path; 5-atmosphere control unit; 6-U-shaped tube; 7-atmosphere volatile source; 8-second three-way valve; 9-first gas outlet path; 10-heat tracing band; 11-ceramic clamp; 12-sample to be tested; 13-detection unit; 14-wire; 15-signal collection unit. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be apparently and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0032] Reference to "an embodiment" in this document means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification is not necessarily all referring to the same embodiment, nor is it necessarily referring to a particular alternative embodiment. It will be explicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0033] The purpose of the present application is to provide a large image surface long working distance objective system for micro projection, the present application sets up lens group, and sets up the material and number of lens, solves the problem of low imaging quality caused by projection in long distance, unbalanced lens volume and mass and high cost.

[0034] In order to make the above-mentioned purpose, characteristics and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0035] As shown in Figure 1 The present application provides a controllable atmosphere perovskite durability test device, which comprises:

[0036] The gas cylinder 1, the atmosphere control unit 5, the detection unit 13 and the signal collection unit 15 are connected in sequence;

[0037] The gas cylinder 1 is used to provide test gas, the atmosphere control unit 5 is used to adjust the composition and flow of the test gas according to the preset test requirements and mix with the built-in atmosphere volatile source 7, the living target test environment, the detection unit 13 is used to collect the electrical signal and impedance change data of the sample to be tested 12 in the target test environment, and the signal collection unit 15 is used to receive the electrical signal and impedance change data collected by the detection unit 13 and evaluate to obtain the durability performance evaluation result.

[0038] The impedance growth rate is obtained by calculating the percentage of the impedance value recorded by the test time relative to the initial value, and the calculation formula is as follows:

[0039]

[0040] Wherein, η(t) is the impedance growth rate, is the impedance at t moment, is the initial impedance. By evaluating the impedance growth rate of the perovskite material, the durability of different perovskite materials is obtained.

[0041] Further, the to-be-tested sample 12 is a perovskite electrode material and an electrolyte supported half-cell structure;

[0042] The to-be-tested sample 12 structure provided in the following specific embodiments of the application comprises: Y0.08Zr0. 92 O2 electrolyte, Gd 0.1 Ce 0.9 O2 barrier layer and to-be-tested perovskite material as to-be-tested working electrode, wherein the electrolyte support is obtained by a tape casting sintering process, the barrier layer is obtained by screen printing on the electrolyte and then sintering, and the to-be-tested perovskite material is obtained by screen printing on the barrier layer and then sintering to obtain the to-be-tested sample 12, as shown in Figure 2 .

[0043] Further, as shown in Figure 3 , the test gas comprises: oxygen, nitrogen, Cr-containing atmosphere, silicon-containing atmosphere, carbon dioxide, sulfur dioxide and water vapor.

[0044] Further, the atmosphere control unit 5 comprises:

[0045] The first gas inlet path 2, the first three-way valve 3, the second gas inlet path 4, the U-shaped pipe 6, the atmosphere volatilization source 7, the second three-way valve 8 and the first gas outlet path 9 and the second gas outlet path;

[0046] One end of the first gas inlet path 2 is connected with the gas cylinder 1, the other end of the first gas inlet path 2 is connected with the second gas inlet path 4 and the second three-way valve 8 through the first three-way valve 3, the atmosphere volatilization source 7 is built-in in the lowest end of the U-shaped pipe 6, the second gas inlet path 4 is connected with the gas inlet of the U-shaped pipe 6, one end of the first gas outlet path 9 is connected with the gas outlet of the U-shaped pipe 6, the other end of the first gas outlet path 9 is connected with one end of the second gas outlet path through the second three-way valve 8, and the other end of the second gas outlet path is connected with the detection unit 13;

[0047] The first three-way valve 3 is used for adjusting the direction of the test gas, the second three-way valve 8 is used for adjusting the direction of the gas in the target test environment, and the atmosphere volatilization source 7 is used for volatilizing various atmosphere gases.

[0048] Specifically, the detection unit 13 is provided with a ceramic clamp 11 and a sample 12 to be detected. The atmosphere control unit 5 is provided with a U-shaped tube 6 and an atmosphere volatile source 7.

[0049] More specifically, the detection unit 13 is a small open tube furnace available on the market, such as the OTF-1200X-S-Ⅱ tube furnace of Hefei Kejing Company. The tube furnace can be heated to a maximum of 1100°C, meeting the requirements for simulating the high-temperature working environment of different perovskite materials. The tube furnace is provided with a ceramic clamp 11 which can be used to fix the sample 12 to be detected.

[0050] The atmosphere control unit 5 is also the OTF-1200X-S-Ⅱ tube furnace available on the market of Hefei Kejing Company, meeting the temperature required for different atmosphere volatile sources 7 to volatilize different atmospheres. The tube furnace is provided with a U-shaped tube 6 which can be used to place different atmosphere volatile sources 7.

[0051] The atmosphere control unit 5 specifically includes a U-shaped tube 6 and an atmosphere volatile source 7. The U-shaped tube 6 is in communication with the first three-way valve 3 through the second gas inlet path 4, and with the second three-way valve 8 and the second gas outlet path through the first gas outlet path 9. When it is necessary to detect the Cr poisoning resistance of perovskite materials, a chromium oxide block is used as the atmosphere volatile source 7 and placed in the U-shaped tube 6. When it is necessary to detect the Si poisoning resistance of perovskite materials, a silicate-based sealing material is used as the atmosphere volatile source 7 and placed in the U-shaped tube 6.

[0052] The sample 12 to be detected is placed in the detection unit 13, the surface of the sample 12 to be detected is coated with platinum paste, the lead wire 14 is in contact with the platinum paste, and the signal collection unit 15 collects the impedance signal of the sample 12 to be detected through the lead wire 14. The signal collection device is the commercially available analyzer Gamry Interface 5000E.

[0053] It should be noted that in this embodiment, the Cr poisoning resistance of perovskite materials is detected, and a chromium oxide block is selected as the atmosphere volatile source 7. During testing, the chromium oxide block is placed as the atmosphere volatile source 7 in the U-shaped tube 6, the three-way valve is installed to make the gas cylinder 1 pass through the first gas inlet path 2 to deliver air to the detection unit 13 through the atmosphere control unit 5, and the working temperatures of the atmosphere control unit 5 tube furnace and the detection unit 13 tube furnace are set to make the atmosphere volatile source 7 in the atmosphere control unit 5 volatilize gaseous Cr species, so that the inside of the detection unit 13 reaches the environmental requirements for testing the durability of perovskite materials. The gaseous Cr species diffuses to the sample 12 to be detected and is adsorbed and reacts. Since the gaseous Cr species occupies the active sites of the sample 12 to be detected, the impedance of the sample 12 to be detected changes, and the change of the impedance of the sample 12 to be detected with time is recorded to evaluate the Cr poisoning resistance of perovskite materials.

[0054] This embodiment shows the test results of perovskite material La0.6Sr0.4Co0.2Fe0.8O3(LSCF) commonly used in battery oxygen electrode, and doped modified La0.4Sr0.4Ba0.2Co0.2Fe0.8O3(LSBCF), as shown in Figure 4 and Figure 5 . Figure 6 The impedance growth rate of the two materials over time is shown, and it can be seen that the doped modified LSBCF has more excellent durability.

[0055] Further, the first gas inlet path 2, the second gas inlet path 4, the first gas outlet path 9 and the second gas outlet path are respectively provided with flow meters.

[0056] Further, the material of the U-shaped tube 6 is quartz, which is used to accommodate the atmosphere volatile source 7 such as Cr source and Si source, and the atmosphere is released by heating;

[0057] Further, the second gas outlet path is externally coated with a heat tracing band 10 for maintaining the temperature of the gas delivery pipeline and preventing atmosphere condensation;

[0058] The signal collection unit 15 is an electrochemical analysis instrument for real-time measurement of the impedance change of the sample 12 to be measured, so as to evaluate its durability;

[0059] By adjusting the temperature of the atmosphere control unit 5 and the types of atmosphere volatile source 7, single or multiple corrosion atmospheres can be simulated to realize accelerated degradation test or durability evaluation under actual service atmosphere,

[0060] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between each embodiment can be referred to each other.

[0061] The principles and implementation modes of the present application are described by applying specific examples in this paper, and the above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In view of the above, the content of the specification should not be understood as a limitation of the present application.

Claims

1. An atmosphere-controllable perovskite durability test device, characterized by, The application relates to a test device for evaluating the durability of perovskite electrode materials and electrolyte-supported half-cell structures. The device comprises a gas cylinder, an atmosphere control unit, a detection unit and a signal collection unit connected in sequence. The gas cylinder is used for providing test gas, the atmosphere control unit is used for adjusting the composition and flow of the test gas according to preset test requirements and mixing with an internal atmosphere volatile source, a target test environment is provided, the detection unit is used for collecting the electrical signal and impedance change data of a sample to be tested in the target test environment, and the signal collection unit is used for receiving the electrical signal and impedance change data collected by the detection unit and performing evaluation to obtain a durability evaluation result.

2. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, The test gas comprises oxygen, nitrogen, hydrogen and water vapor.

3. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, The atmosphere control unit comprises a first gas inlet path, a first three-way valve, a second gas inlet path, a U-shaped pipe, an atmosphere volatile source, a second three-way valve and a first gas outlet path and a second gas outlet path. One end of the first gas inlet path is connected with the gas cylinder, the other end of the first gas inlet path is connected with the second gas inlet path and the second three-way valve through the first three-way valve, the atmosphere volatile source is internally arranged in the lowest end of the U-shaped pipe, the second gas inlet path is connected with the gas inlet port of the U-shaped pipe, one end of the first gas outlet path is connected with the gas outlet port of the U-shaped pipe, the other end of the first gas outlet path is connected with one end of the second gas outlet path through the second three-way valve, and the other end of the second gas outlet path is connected with the detection unit. The first three-way valve is used for adjusting the flow direction of the test gas, the second three-way valve is used for adjusting the flow direction of the test gas in the target test environment, and the atmosphere volatile source is used for volatilizing various atmosphere gases. Flowmeters are arranged on the first gas inlet path, the second gas inlet path, the first gas outlet path and the second gas outlet path respectively.

4. The atmosphere-controllable perovskite durability test device according to claim 3, characterized by, The detection unit and the atmosphere control unit are both tubular furnaces.

5. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, The sample to be tested is a perovskite electrode material and an electrolyte-supported half-cell structure.

6. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, The material of the U-shaped pipe is quartz.

7. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, The second gas outlet path is externally wrapped with a heat tracing band.

8. The atmosphere-controllable perovskite durability test device according to claim 1, characterized by, ​

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