An oxygen-ion conductor material with a Ruddlesden-Popper type layered perovskite structure and a preparation method thereof

Abstract

A class of oxygen ion conductor materials Sr3Zr with a Ruddlesden-Popper (RP) type layered perovskite structure 2‑x In x O 7‑0.5x (x=0.1, 0.2, 0.3) and their preparation methods. The specific steps are as follows: (1) SrCO3, ZrO2 and In2O3 raw materials with a purity of 99.5% (mass percentage) or higher are combined according to different designed molar ratios (Sr3Zr 1.9 In 0.1 O 6.95 Sr3Zr 1.8 In 0.2 O 6.9 Sr3Zr 1.7 In 0.3 O 6.85 (1) Weigh the ingredients; place the weighed raw materials in a mortar, add an appropriate amount of anhydrous ethanol and grind for 30 min; (2) Press the ground powder into tablets using a mold, and pre-calcine at 1400℃ for 12 h using a high-temperature solid-state method to obtain the pre-calcined material. (3) Crush and grind the pre-calcined material in a mortar to obtain a mixture, weigh about 0.4 g, press it into a disc, and sinter it at 1600℃ for 12 h to obtain a dense ceramic disc. XRD test was performed on it to obtain the target product phase Sr3Zr2O7. EIS impedance test was performed on it to analyze its electrical properties. The product of this invention has high conductivity and the preparation method is simple and low cost.

Description

Technical Field

[0001] This invention belongs to the field of inorganic materials and solid-state chemistry, specifically relating to a class of oxygen ion conductor materials, Sr3Zr, with a Ruddlesden-Popper (RP) type layered perovskite structure. 2-x In x O 7-0.5x (x=0.1, 0.2, 0.3) Ceramics and their preparation methods. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are energy conversion devices that can directly and efficiently convert the chemical energy of fuel into electrical energy. Their electrolytes require high, pure ionic conductivity, as low as possible electronic conductivity, and excellent phase stability and redox stability. Oxygen ion conductors refer to compounds with oxygen ion migration properties. Many novel oxygen ion conductor materials have been reported to date, such as La2Mo2O9-based materials with oxygen ion conductivity. Many more known novel oxygen ion conductor materials possess perovskite structures or perovskite-related structures. Using perovskite as the structural unit, numerous related structures can be derived, known as perovskite-like structures. Among these, layered perovskite is an important perovskite-like structural material. The Ruddlesden-Popper (RP) type layered perovskite structure material has been reported and extensively studied. Its B-site ions are usually metal ions with variable valence states, exhibiting mixed electron-ion conductivity properties. For example, Sr3Zr2O7 material has been reported to have an RP structure, but its oxygen ion conductivity has not yet been reported. The present invention prepares Sr3Zr2O7 acceptor-doped oxygen ion conductor material based on RP-type layered perovskite structure. 2-x In x O 7-0.5x (x=0.1, 0.2, 0.3), and its conductivity was found to be relatively lower than that of the parent Sr3Zr2O7 material (7.11×10). -6 The conductivity (S / cm) increased by nearly three orders of magnitude. In air, the component with In=0.2 exhibited the highest conductivity, reaching 3.22×10⁻⁶. -3 S / cm; Complex impedance spectroscopy indicates that the parent Sr3Zr2O7 material shows no significant electrode response across the entire temperature range (300–900 °C), exhibiting electronic conductivity and thus being an electronically conductive material. Meanwhile, Sr3Zr... 2-x In x O 7-0.5x EIS impedance testing of the materials (x=0.1, 0.2, 0.3) showed that a Warburg electrode response was clearly observed at 300℃, and this response gradually collapsed at high temperatures, indicating that the doped material exhibits ionic conductivity. Furthermore, Sr3Zr prepared using solid-state sintering...2-x In x O 7-0.5x Materials with x=0.1, 0.2, and 0.3 are novel oxygen ion conductors with potential, characterized by simple methods and low cost. By controlling oxygen vacancies, concentrations, conductivity, and redox stability in the material through dominant doping, directions are provided for further development and optimization of RP-type electrolyte materials. Summary of the Invention

[0003] The purpose of this invention is to provide a class of oxygen ion conductor materials, Sr3Zr, with a Ruddlesden-Popper (RP) type layered perovskite structure. 2-x In x O 7-0.5x (x=0.1, 0.2, 0.3) Ceramics and their preparation methods. Preparation of Sr3Zr 2- x In x O 7-0.5x The specific steps for (x=0.1, 0.2, 0.3) are as follows:

[0004] (1) Raw materials SrCO3, ZrO2, and In2O3, all with a purity of 99.5% or higher (mass percentage), are mixed according to different designed molar ratios (Sr3ZrO2, ZrO2, and In2O3). 1.9 In 0.1 O 6.95 Sr3Zr 1.8 In 0.2 O 6.9 Sr3Zr 1.7 In 0.3 O 6.85 The ingredients are weighed and mixed. Generally, the product is prepared in 3g increments. The weighed raw materials are placed in a mortar, an appropriate amount of anhydrous ethanol is added, and the mixture is ground repeatedly for more than an hour. Then, it is dried under an infrared lamp.

[0005] (2) The dried powder was pressed into tablets using a Φ20 mold and pre-calcined at 1400℃ for 12 hours using a high-temperature solid-state method. The temperature was increased and decreased at a rate of approximately 5℃ / min to obtain the pre-calcined material.

[0006] (3) After crushing and grinding the pre-fired material in step (2) with a mortar and pestle, a mixture was obtained. Approximately 0.4g of each mixture was weighed and pressed into Φ10 ceramic sheets. Dense ceramic sheets were obtained by sintering at 1600℃ for 12h. XRD analysis was performed on the ceramic sheets to obtain the target product phase Sr3Zr2O7.

[0007] (4) Perform EIS impedance testing on the ceramic sheet sintered in step (3). First, coat both sides of the ceramic sheet with platinum paste in an impedance furnace, connect them with platinum wire, and hold at 850°C for two hours. The purpose of this step is to volatilize the organic matter in the platinum paste. Then, test its impedance under atmospheres such as air, nitrogen, and humid nitrogen. By analyzing and processing the impedance data, we can obtain its conductivity and complex impedance diagram.

[0008] The Sr3Zr prepared by this invention 2-x In x O 7-0.5x (x=0.1, 0.2, 0.3) Oxygen ion conductor materials exhibit high electrical conductivity, which is nearly three orders of magnitude higher than that of the parent material Sr3Zr2O7. In an air atmosphere, the composition with In=0.2 has the highest conductivity, reaching 3.22×10⁻⁶. -3 S / cm; and Sr3Zr prepared using solid-state sintering method 2-x In x O 7-0.5x (x=0.1, 0.2, 0.3) materials, the method is simple and the cost is low, and they are new oxygen ion conductor materials with certain potential. Attached Figure Description

[0009] Figure 1 The Sr3Zr material prepared in Examples 2-4 2-x In x O 7-0.5x X-ray diffraction (XRD) patterns of (x=0.1, 0.2, 0.3).

[0010] Figure 2 These are the transmission electron microscope (SEM) electron diffraction (SAED) patterns of the materials prepared in Examples 1, 3, and 4. Figures (a), (b), and (c) show the Sr3Zr2O7, Sr3Zr, and Sr2O7 materials, respectively. 1.8 In 0.2 O 6.9 Sr3Zr 1.7 In 0.3 O 6.85 SAED diagram.

[0011] Figure 3 The parent compounds Sr3Zr2O7 and Sr3Zr prepared in Examples 1-4 are 1.9 In 0.1 O 6.95 Sr3Zr 1.8 In 0.2 O 6.9 Sr3Zr 1.7 In 0.3 O 6.85 A comparison of the electrical conductivity of the materials in air atmosphere.

[0012] Figure 4 The Sr3Zr2O7 and Sr3Zr prepared in Examples 1 and 4 1.7 In 0.3 O 6.85 Complex impedance diagrams of the materials. Figures (a) and (b) show the complex impedance diagrams of the parent Sr3Zr2O7 material at 550℃ and 850℃ in air atmosphere, respectively; Figures (c) and (d) show the complex impedance diagrams of Sr3Zr2O7 material at 550℃ and 850℃, respectively. 1.7 In 0.3 O 6.85 Complex impedance diagrams of the material at 500℃ and 900℃ in air atmosphere. Detailed Implementation

[0013] The following detailed description is provided by way of specific embodiments. These embodiments are implemented based on the technical solution of the present invention, and provide detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments.

[0014] Example 1:

[0015] Example 1 describes the design to generate 0.1 mol of the target product SrZr2O7 material. 0.1 mol of SrCO3 and 0.2 mol of ZrO2 were weighed, placed in a mortar, and ground thoroughly for at least one hour with the addition of an appropriate amount of alcohol. The mixture was then dried under an infrared lamp, and the resulting powder was pressed into tablets using a Φ20 mold. The tablets were pre-calcined at 1400℃ for 12 hours using a high-temperature solid-state method to obtain the pre-calcined material. The pre-calcined material was crushed, and alcohol was added and ground in a mortar to obtain a mixture. Approximately 0.4 g of each mixture was weighed, pressed into Φ10 discs, and sintered at 1600℃ for 12 hours. XRD analysis was then performed to obtain the target product phase Sr3Zr2O7. The sintered ceramic discs were then subjected to impedance testing. First, platinum paste was coated on both sides of the ceramic discs in an impedance furnace. After being connected with platinum wire, the discs were held at 850℃ for two hours. This step was to allow the organic matter in the platinum paste to volatilize. Then, EIS tests were performed under air, nitrogen, and humid nitrogen atmospheres, respectively. By analyzing and processing the impedance data, we can obtain its conductivity and complex impedance diagram.

[0016] Example 2:

[0017] Example 2 of this study aims to generate 0.1 mol of the target product SrZr. 1.9 In 0.1 O 6.95Materials. Weigh 0.1 mol SrCO3, 0.19 mol ZrO2, and 0.05 mol In2O3. Place the weighed raw materials in a mortar, add an appropriate amount of alcohol, and grind thoroughly for more than 1 hour. Dry under an infrared lamp, and press the resulting mixed powder into tablets using a Φ20 mold. Pre-calcine at 1400℃ for 12 hours using a high-temperature solid-state method to obtain the pre-calcined material. Crush the pre-calcined material, add alcohol, and grind it in a mortar to obtain a mixture. Weigh approximately 0.4 g of each mixture, press it into Φ10 discs, and sinter at 1600℃ for 12 hours. XRD analysis of the discs yields the target product phase Sr3Zr2O7. Then, perform impedance testing on the sintered ceramic discs. First, coat both sides of the ceramic discs with platinum paste in an impedance furnace, connect them with platinum wire, and hold at 850℃ for two hours. This step aims to volatilize the organic matter in the platinum paste. Then, EIS tests were performed under air, nitrogen, and humid nitrogen atmospheres, respectively. By analyzing and processing the impedance data, we can obtain its conductivity and complex impedance diagram.

[0018] Example 3:

[0019] Example 3 of this study designed to generate 0.1 mol of the target product SrZr. 1.8 In 0.2 O 6.9 Materials. Weigh 0.1 mol SrCO3, 0.18 mol ZrO2, and 0.1 mol In2O3. Place the weighed raw materials in a mortar, add an appropriate amount of alcohol, and grind thoroughly for more than 1 hour. Dry under an infrared lamp, and press the resulting mixed powder into tablets using a Φ20 mold. Pre-calcine at 1400℃ for 12 hours using a high-temperature solid-state method to obtain the pre-calcined material. Crush the pre-calcined material, add alcohol, and grind it in a mortar to obtain a mixture. Weigh approximately 0.4 g of each mixture, press it into Φ10 discs, and sinter at 1600℃ for 12 hours. XRD analysis of the discs yields the target product phase Sr3Zr2O7. Then, perform impedance testing on the sintered ceramic discs. First, coat both sides of the ceramic discs with platinum paste in an impedance furnace, connect them with platinum wire, and hold at 850℃ for two hours. This step aims to volatilize the organic matter in the platinum paste. Then, EIS tests were performed under air, nitrogen, and humid nitrogen atmospheres, respectively. By analyzing and processing the impedance data, we can obtain its conductivity and complex impedance diagram.

[0020] Example 4:

[0021] Example 4 of this study designed to generate 0.1 mol of the target product SrZr. 1.7 In 0.3 O 6.85Materials. Weigh 0.1 mol SrCO3, 0.17 mol ZrO2, and 0.15 mol In2O3. Place the weighed raw materials in a mortar, add an appropriate amount of alcohol, and grind thoroughly for more than 1 hour. Dry under an infrared lamp, and press the resulting mixed powder into tablets using a Φ20 mold. Pre-calcine at 1400℃ for 12 hours using a high-temperature solid-state method to obtain the pre-calcined material. Crush the pre-calcined material, add alcohol, and grind it in a mortar to obtain a mixture. Weigh approximately 0.4 g of each mixture, press it into Φ10 discs, and sinter at 1600℃ for 12 hours. XRD analysis of the discs yields the target product phase Sr3Zr2O7. Then, perform impedance testing on the sintered ceramic discs. First, coat both sides of the ceramic discs with platinum paste in an impedance furnace, connect them with platinum wire, and hold at 850℃ for two hours. This step aims to volatilize the organic matter in the platinum paste. Then, EIS tests were performed under air, nitrogen, and humid nitrogen atmospheres, respectively. By analyzing and processing the impedance data, we can obtain its conductivity and complex impedance diagram.

[0022] Figure 1 X-ray diffraction (XRD) patterns of the products obtained in Examples 2, 3, and 4 are given. Figure 2 Electron diffraction (SAED) patterns of the materials prepared in Examples 1, 3, and 4 are shown under a transmission electron microscope. Figure 3 A comparison graph of the conductivity obtained from testing the materials prepared in Examples 1, 2, 3, and 4 is provided. Figure 4 Complex impedance diagrams of the products obtained in Examples 1 and 4 are provided.

Claims

1. A class of oxygen ion conductor materials with a Ruddlesden-Popper type layered perovskite structure, Sr3Zr 2-x In x O 7-0.5x A method for preparing ceramics, characterized in that, The specific preparation method is as follows: x = 0.1, 0.2, 0.3; (1) Weigh and mix the raw materials SrCO3, ZrO2 and In2O3 with a purity of 99.5wt% or higher according to different designed molar ratios; prepare 3 g of product, place the weighed raw materials in a mortar, add an appropriate amount of anhydrous ethanol, grind repeatedly for more than an hour, and dry under an infrared lamp. (2) The dried powder was pressed into tablets using a Φ20 mold. The sample was placed in a high-temperature sintering muffle furnace using the high-temperature solid-state method and pre-fired at 1400℃ for 12 hours. The temperature was increased and decreased at a rate of 5℃ / min to obtain the pre-fired material. (3) After crushing and grinding the pre-fired material in step (2) with a mortar, a mixture is obtained. 0.4g of each mixture is weighed and pressed into Φ10 discs. The target product phase Sr3Zr2O7 is obtained by XRD testing after sintering at 1600℃ for 12h. The sample is heated and cooled at a rate of 5℃ / min to obtain dense ceramic discs. (4) Perform EIS impedance testing on the ceramic sheet sintered in step (3); first, coat both sides of the ceramic sheet with platinum paste in the impedance furnace device, connect them with platinum wire, and keep them at 850°C for two hours. The purpose of this step is to volatilize the organic matter in the platinum paste; then test its impedance in air and nitrogen atmosphere, and obtain its conductivity and complex impedance diagram by analyzing and processing the impedance data.

2. The oxygen ion conductor material Sr3Zr with a Ruddlesden-Popper type layered perovskite structure as described in claim 1 2-x In x O 7-0.5x A method for preparing ceramics, characterized in that, Oxygen vacancy defects are created by acceptor doping In elements into the parent Sr3Zr2O7, forming a pure phase Sr3Zr2O7.

3. A type of oxygen ion conductor material Sr3Zr with a Ruddlesden-Popper type layered perovskite structure as described in claim 1. 2-x In x O 7-0.5x The preparation method of the [method] is characterized by, With In doping ratios of 0.1, 0.2, and 0.3, EIS impedance testing results showed that the material had good electrical properties, with a noticeable electrode response observed only at 300℃.

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