Double perovskite material and its manufacturing method, and reversible proton ceramic electrochemical cell

Abstract

To specifically provide a double perovskite material, a manufacturing method of the same, and a reversible proton ceramic electrochemical battery, while relating to a field of the reversible proton ceramic electrochemical battery.SOLUTION: A formula of a double perovskite material is PrBa0.9Cs0.1Co2O6-δ, where δ represents an oxygen vacancy content. The present invention further provides a manufacturing method of the double perovskite material, and a reversible proton ceramic electrochemical battery containing the double perovskite material. The double perovskite material in which Cs+ is doped, that is provided by the present invention exhibits excellent stability, relatively low polarization impedance, and relatively high ORR / OER activation. The reversible proton ceramic electrochemical battery provided by the present invention exhibits excellent stability, electrocatalytic activation, and electrochemical performance.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] This invention relates to the field of reversible proton ceramic electrochemical batteries, and more particularly to double perovskite materials, methods for producing the same, and reversible proton ceramic electrochemical batteries. [Background technology]

[0002] The finite nature of fossil fuel storage and the intensification of greenhouse gas emissions create a strong need to find clean and pollution-free energy conversion devices to mitigate the current energy and environmental crises. Reversible proton ceramic electrochemical cell (R-PCEC) technology can be one effective means of solving these problems. When operating in fuel cell mode, a reversible proton ceramic electrochemical cell can convert chemical energy into electrical energy, and when operating in electrolysis mode, it can convert electrical energy into chemical energy. Furthermore, because R-PCECs, based on proton-conducting electrolytes, have relatively high proton conductivity, they can operate at medium to low temperatures (400-700°C). The relatively low operating temperature of R-PCECs is advantageous not only for extending the lifespan of the cell itself but also for reducing manufacturing costs. However, as the operating temperature of R-PCECs decreases, the reaction kinetics of the air electrode also slow down, and the electrochemical performance of R-PCECs deteriorates significantly. Therefore, designing air electrode materials that have high catalytic activity in oxygen reduction (ORR) / oxygen evolution (OER) reactions and sufficient chemical stability under operating conditions at medium to low temperatures is one of the most critical challenges facing R-PCEC.

[0003] In recent years, researchers have designed many air electrode materials, but most of them exhibit moderate electrochemical performance in R-PCEC. One example is the double perovskite material PrBaCo2O. 6-δPBC (Perovskite Cellular Condensation) possesses excellent electrical conductivity, oxygen ion conductivity, superior oxygen surface exchange coefficient, and oxygen ion diffusion dynamics, exhibiting excellent electrochemical performance as an air electrode in solid oxide fuel cells (SOFCs). Cesium (Cs) is sometimes used in the design of perovskite solar cell materials because Cs doping enhances the thermal stability and moisture resistance of the material's crystal structure. According to density functional theory (DFT) calculations, the main reason for the improved ORR activity of air electrodes after Cs doping is the shift of electron pairs due to the polarization distribution of Lewis acid strength at the A and B sites, which further reduces the oxygen vacancy formation energy of the oxide. Currently, there are few reports on the application of air electrodes designed by Cs doping at the A site to R-PCEC. [Overview of the project] [Problems that the invention aims to solve]

[0004] To solve the above problems, the present invention provides a double perovskite material, a method for producing the same, and a reversible proton ceramic electrochemical cell. The present invention provides (low Lewis acid strength cation Cs + The doped (Cs) double perovskite material has good electrochemical stability, relatively low polarization impedance, and relatively high ORR / OER activity. The present invention relates to the low Lewis acid strength cation Cs + The present invention further provides a method for producing a doped double perovskite material. Based on the double perovskite material, the present invention further provides a reversible proton ceramic electrochemical cell having excellent electrochemical performance and good stability. [Means for solving the problem]

[0005] Specifically, in a first embodiment, the present invention provides a double perovskite material, the general formula of the double perovskite material being PrBa 1-x Cs x Ho2O 6-δ Here, δ is the oxygen vacancy content.

[0006] According to the present invention, when doping with an A-site dopant having a relatively low acidity, it is advantageous for improving the hydration ability of perovskite oxide. Also, in the air electrode of a fuel cell, applying Cs as an A-site cation dopant is closely related to the kinetics of the redox reaction of the air electrode and the Lewis acid strength of the doped ions. Cs + When used as an A-site dopant, due to the shift of the electron pair caused by the polarization distribution of the Lewis acid strength between the A-site ions and the B-site ions, the oxygen vacancy content in the oxide is improved, which is advantageous for improving the oxygen exchange kinetics on the electrode surface and accelerating the redox reaction process. Therefore, Cs + doping can effectively improve the catalytic activity of the air electrode and further improve the electrochemical performance of R-PCEC at medium and low temperatures. And a part of Ba in the double perovskite oxide PBC can be replaced by a cation Cs + with a low Lewis acid strength. Furthermore, in the present invention, as the air electrode of R-PCEC, a novel double perovskite material PrBa 1-x Cs x Co2O 6-δ (PBCsC) was designed and manufactured, and its electrocatalytic activity and water decomposition ability at medium and low temperatures were evaluated. This has important practical significance for the design and realization of an air electrode with high catalytic activity and stability and its application to R-PCEC.

[0007] Preferably, the range of the value of x is 0.01 to 0.15.

[0008] More preferably, the range of the value of x is 0.05 to 0.125.

[0009] Preferably, the double perovskite material has a square layered perovskite structure. The double perovskite material has a perovskite structure in which Cs is doped at the A-site. In the present invention, the ionic radius of Cs is 167 pm, the ionic radius of Ba is 135 pm, and the ionic radius of Ba is the closest to Cs (Pr 3+ and Pr4+ The ionic radii of Co are 99 and 85 pm. 2+ Co 3+ Co 4+ The ionic radii of this compound are 74.5, 61, and 53 pm, and the Ba ions in the structure are Cs + It is replaced by. More preferably, the lattice constants are a = 3.9045 ± 0.1 Å, b = 3.9045 ± 0.1 Å, and c = 7.6572 ± 0.1 Å.

[0010] More preferably, the general formula of the double perovskite material is PrBa 0.9 Cs 0.1 Ho2O 6-δ Here, 0.1 ≤ δ ≤ 0.3.

[0011] According to the present invention, further research has revealed that PBCsC using the above x value in the present invention has excellent electrocatalytic performance. In particular, when a preferred x=0.1 is used and partial substitution of Ba is performed, surprisingly, the reversible proton ceramic electrochemical cell can be given superior electrochemical performance and stability compared to cases where other values ​​are taken.

[0012] In a second embodiment, the method for producing the double perovskite material provided by the present invention is: (1) Dissolve praseodymium nitrate, barium nitrate, cesium nitrate, and cobalt nitrate in water to obtain a mixture, then mix the mixture with ethylenediaminetetraacetic acid, citric acid, and ammonia water to adjust the pH to 7-8 to obtain a mixed solution, and (2) The mixed solution is heated until it becomes gel-like, and then subjected to high-temperature treatment at 200-250°C to obtain a precursor, after which the precursor is calcined. Includes.

[0013] Preferably, in step (1), the molar ratio of the metal element, ethylenediaminetetraacetic acid, and citric acid is 0.5 to 1.5:0.5 to 1.5:1 to 2, and preferably 1:1:1.5, where the metal element is the sum of Pr, Ba, Cs, and Co. Test studies have shown that the present invention, by using specific proportions of the metal element, ethylenediaminetetraacetic acid, and citric acid and combining them with the preferred firing temperature in the present invention, allows for the formation of PrBa 0.9 Cs 0.1 Ho2O 6-δ The phase formation effect (crystal strength) of PrBa can be significantly improved, 0.9 Cs 0.1 Ho2O 6-δ It was discovered that this can exhibit a superior crystal structure.

[0014] Preferably, in step (2), the heating temperature of the mixed solution is 80 to 100°C.

[0015] Preferably, in step (2), the time of the high-temperature treatment is 2 to 6 hours, and preferably 2 hours.

[0016] Preferably, in step (2), the firing temperature is 950 to 1050°C, preferably 1000°C, and the firing time is 2 to 4 hours, preferably 2 hours.

[0017] In the present invention, by combining the raw materials used with preferred manufacturing conditions, the phase formation effect can be made more favorable, resulting in PrBa having superior crystal strength and crystal structure. 0.9 Cs 0.1 Ho2O 6-δ This is advantageous for manufacturing, and furthermore, the reversible proton ceramic electrochemical cell produced can have superior overall performance in terms of electrochemical performance and stability.

[0018] In a third aspect, the present invention provides the use of the double perovskite material and the use of the double perovskite material as an air electrode in a reversible proton ceramic electrochemical cell.

[0019] In a fourth embodiment, the present invention further provides an anode-supported reversible proton ceramic electrochemical cell comprising sequentially connected anode support layers, an electrolyte, and an air electrode, wherein the air electrode is a cation of the above-mentioned low Lewis acid strength Cs + It is manufactured from a doped (double perovskite) material.

[0020] Preferably, the electrolyte material contains BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb1711) is included, where δ is the oxygen vacancy content (0 ≤ δ ≤ 0.2).

[0021] Preferably, the material of the anode support layer contains NiO and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ This includes NiO and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ The mass ratio is 5.5-6.5:3.5-4.5, preferably 6:4, where δ is the oxygen vacancy content.

[0022] Preferably, the reversible proton ceramic electrochemical cell further includes a transition layer, the transition layer being provided between the anode support layer and the electrolyte. Preferably, the transition layer contains NiO and BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ (BZCYYb1711) contains NiO and BaZr 0.1 Ce 0.7 Y0.1 Yb 0.1 O 3-δ The mass ratio is 5.5-6.5:3.5-4.5, preferably 6:4, where δ is the oxygen vacancy content.

[0023] According to the present invention, the term δ in each layer of a reversible proton ceramic electrochemical cell means the oxygen vacancy content, and unless the range is limited in the present invention, it means that the range of oxygen vacancy content that is common in the art, for example, 0 to 0.5, 0.1 to 0.4, or 0.1 to 0.2 may be adopted.

[0024] In this invention, by using a co-casting method, the electrolyte layer, transition layer, and anode layer are closely connected without interlayer separation in the anode-supported proton ceramic electrochemical cell, significantly improving the stability of the half-cell structure and reducing the resistance caused by the connection of the half-cells. As a result, the anode-supported proton ceramic electrochemical cell can exhibit superior electrochemical performance.

[0025] More preferably, the method for manufacturing the anode-supported reversible proton ceramic electrochemical cell is: (1) The steps of preparing the materials for the anode support layer, the transition layer, the electrolyte, and the air electrode into slurries, (2) In a casting apparatus, the electrolyte slurry, transition layer slurry, and anode support layer slurry are sequentially cast, then air-dried for 10 to 14 hours, the co-cast sheets after air-drying are degreased, and then fired at high temperature to obtain a half-cell with anode support (preferably, the heat treatment degreasing conditions are 500 to 700°C for 1 to 3 hours, and the high-temperature firing conditions are 1400 to 1500°C for 4 to 6 hours), and (3) The material for the air electrode is made into a slurry, which is applied to the surface of the electrolyte of the half-cell, and fired at a high temperature to obtain a reversible proton ceramic electrochemical total cell with anode support (preferably, the conditions for the high-temperature firing are 800 to 1000°C for 1 to 3 hours). Includes.

[0026] More preferably, the substrate is a polymer film.

[0027] More preferably, the electrolyte layer slurry is obtained by ball milling BZCYYb1711 powder, a dispersant, and anhydrous ethanol.

[0028] More preferably, the transition layer slurry is obtained by blending BZCYYb1711 powder, nano-nickel oxide, graphite, a dispersant, anhydrous ethanol, and butyl acetate and ball-milling them for 12 hours.

[0029] More preferably, the anode support layer slurry is obtained by blending BZCYYb1711, nickel oxide, graphite, a dispersant, anhydrous ethanol, and butyl acetate and grinding them in a ball mill for 10 to 14 hours.

[0030] More preferably, the air electrode slurry is PrBa 0.9 Cs 0.1 Ho2O 6-δ It is obtained by blending the material with terpineol, and the slurry composition is 1g:0.5~0.7g PrBa 0.9 Cs 0.1 Ho2O 6-δ And terpineol.

[0031] More preferably, in the anode-supported half-cell, the thickness of the electrolyte layer is 7 to 9 μm, the thickness of the anode support layer is 600 to 700 μm, and the thickness of the transition layer is 16 to 22 μm.

[0032] In the present invention, through test studies, it has been discovered that when manufacturing an anode-supported half-cell using the above-mentioned preferred high-temperature firing temperature and time parameters, the mechanical strength of the half-cell can be improved by adjusting the thickness of the anode support layer, resulting in the anode-supported half-cell exhibiting superior structural stability. [Effects of the Invention]

[0033] The beneficial effects of the present invention are at least as follows: The low Lewis acid strength cation Cs of the present invention + The doped double perovskite material is the double perovskite material PrBaCo2O 6-δ Based on this, elemental doping was performed at site A. Using the sol-gel method, the air electrode material PrBa for a reversible proton ceramic electrochemical cell with anode support was used. 0.9 Cs 0.1 Ho2O 6-δ (PBCsC) is manufactured. The air electrode material for the anode-supported reversible proton ceramic electrochemical cell of the present invention has a relatively low polarization impedance and relatively high electrocatalytic activity. The anode-supported single cell manufactured in the present invention, i.e., NiO-BZCYYb1711||transition layer NiO-BZCYYb1711||BZCYYb1711||PBCsC, has a polarization resistance of 0.045 Ωcm at 650°C, 600°C, 550°C, and 500°C, respectively. 2 , 0.094 Ωcm 2 , 0.273 Ωcm 2 and 1.037 Ωcm 2 The maximum power density is 1.66 Wcm². -2 , 1.19Wcm -2 , 0.72Wcm -2 and 0.41 Wcm -2 When humidified air is supplied to the air electrode side and the R-PCEC is operated in electrolysis mode, the current density at a voltage of 1.3V is -2.85 Acm² at 650°C, 600°C, 550°C, and 500°C, respectively. -2 -1.48Acm -2 -0.71Acm -2 , and -0.31Acm -2 The anode-supported reversible proton ceramic electrochemical cell of the present invention possesses excellent stability, oxygen ion exchange dynamics, electrocatalytic activity, and electrochemical performance.

[0034] To more clearly explain the embodiments of the present invention and the technical concepts in the prior art, the drawings that may be used in the description of the embodiments or the prior art are briefly described below. The drawings in the following description are some embodiments of the present invention, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without any creative work. [Brief explanation of the drawing]

[0035] [Figure 1] This is a refined XRD pattern obtained after firing the air electrode material PrBa0.9Cs0.1Co2O6-δ(PBCsC) according to Example 1 of the present invention at 1000°C for 2 hours. [Figure 2] This is an XRD pattern obtained after simultaneously firing the air electrode material PrBa0.9Cs0.1Co2O6-δ(PBCsC) and electrolyte BZCYYb powder according to Example 1 of the present invention in a high-temperature muffle furnace at 950°C for 2 hours. [Figure 3] This is the XRD pattern of the air electrode material PrBa0.9Cs0.1Co2O6-δ(PBCsC) according to Example 1 of the present invention after being treated with 30% water at 600°C for 10 hours. [Figure 4] This is a high-temperature in situ XRD pattern obtained after firing the air electrode material PrBa0.9Cs0.1Co2O6-δ(PBCsC) according to Example 1 of the present invention at 1000°C for 2 hours. [Figure 5] These are the X-ray photoelectron spectra (XPS) of the air electrode materials PBCsC and PBC according to Example 1 of the present invention, where a is Pr 3d and b is Co 2p. [Figure 6] These are the O 1s X-ray photoelectron spectra of the air electrode materials PBCsC(6a) and PBC(6b) according to Example 1 of the present invention. [Figure 7] This is an evaluation diagram of the relaxation characteristics of the air electrode materials PBCsC and PBC according to Example 1 of the present invention. [Figure 8]This figure shows the area specific impedance (8a) and impedance stability (8b) of a symmetric battery according to Example 1 of the present invention (where PBCsC is the electrode and BZCYYb1711 is the electrolyte support) in humid air (3% H2O). [Figure 9] This figure shows the electrochemical stability of a symmetrical battery according to Example 1 of the present invention (where PBCsC and PBC are electrodes and BZCYYb1711 is the electrolyte support) in humid air (3% H2O). [Figure 10] This is the infrared spectrum obtained after treating PBCsC and PBC oxide according to Example 1 of the present invention at 600°C for 50 hours with air containing 30% water vapor. [Figure 11] This figure shows the maximum power density when a single cell (Ni-BZCYYb1711||transition layer Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured using PBCsC as the air electrode in Example 2 of the present invention, with Ni-BZCYYb1711 as the fuel electrode support, is measured in FC mode (humidified hydrogen gas is supplied to the anode side and air is supplied to the oxygen electrode side) within the range of 650 to 500°C. [Figure 12] This figure shows the current density corresponding to 1.3V when a single cell (Ni-BZCYYb1711||transition layer Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured using PBCsC as the air electrode in Example 2 of the present invention, with Ni-BZCYYb1711 as the fuel electrode support, was measured in EC mode (humidified hydrogen gas is supplied to the anode side and humidified air is supplied to the oxygen electrode side) within the range of 650 to 500°C. [Figure 13] This figure shows the operational stability of a single cell (Ni-BZCYYb1711||transition layer Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured according to Example 2 of the present invention, using PBCsC as the air electrode and Ni-BZCYYb1711 as the anode support, measured at 650°C in fuel cell mode and electrolytic cell mode. [Figure 14]This figure shows the cycle stability of a single cell (Ni-BZCYYb1711||transition layer Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured according to Example 2 of the present invention, with PBCsC as the air electrode and Ni-BZCYYb1711 as the fuel electrode support, measured at 600°C. [Figure 15] This figure shows the change in the Faraday efficiency of a single cell (Ni-BZCYYb1711||transition layer Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured according to Example 2 of the present invention, with PBCsC as the air electrode and Ni-BZCYYb1711 as the anode support layer, as a function of the applied current density. [Figure 16] This figure shows the change in hydrogen production rate with respect to the applied current density of a single cell (Ni-BZCYYb1711||transition Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured using PBCsC as the air electrode and Ni-BZCYYb1711 as the anode support layer according to Example 2 of the present invention. [Modes for carrying out the invention]

[0036] To clarify the purpose, technical concept, and advantages of the embodiments of the invention, the technical concept in the embodiments of the invention will be described clearly and completely below. It will be obvious that the embodiments described are some, but not all, embodiments of the invention. All other embodiments that a person skilled in the art can obtain without creative work based on the embodiments of the invention are all within the scope of the protection of the invention.

[0037] Unless otherwise specified, all raw materials and reagents used in the following examples are either commercially available or can be manufactured by known methods. Where specific techniques or conditions are not explicitly stated in the examples, they should be carried out according to conventional methods, techniques or conditions described in the literature in the art, or according to the product instructions. Where the manufacturer of reagents or equipment is not specified, they are all standard products that can be purchased through legitimate channels.

[0038] Hereinafter, the present invention will be described in more detail by combining examples.

[0039] Examples of the present invention relate to the production and property evaluation of an air electrode material doped with a cation Cs having a low Lewis acid strength, and the composition molecular formula of the air electrode material is PrBa + Cs 0.9 Cs 0.1 Co2O 6-δ (PBCsC). By doping Cs ions at the A site in the perovskite material PrBaCo2O 6-δ , the oxygen reduction / evolution reaction activity and stability of an anode-supported reversible proton ceramic electrochemical cell are improved. By doping Cs at the A site, the catalytic activity and stability of the PrBa + Cs 0.9 Cs 0.1 Co2O 6-δ (PBCsC) air electrode are both improved. At 650 °C, a single cell with a composition of Ni-BZCYYb1711|transition layer Ni-BZCYYb1711|BZCYYb1711|PBCsC has a maximum output power of 1.66 Wcm -2 in the FC mode, and the polarization resistance of the cell is only 0.045 Ωcm 2 . After supplying air containing 3% water vapor to the air electrode side, a current density of -2.85 Acm -2 is obtained under the voltage conditions of 650 °C and 1.3 V. The present invention can significantly reduce the polarization impedance of the PrBaCo2O + 6-δ air electrode by doping a cation Cs with a low Lewis acid strength, and improve the electrochemical performance of the entire cell. In the electrolysis mode, the current density can be significantly improved and excellent stability can be shown.

[0040] ​At present, there are relatively few studies on the cycle stability of reversible proton ceramic electrochemical cells with medium and low temperature anode supports, and the characteristic evaluation methods for the stability of reversible proton ceramic electrochemical cells are also extremely rare. In order to evaluate the cycle stability characteristics of the reversible proton ceramic electrochemical cell according to the present invention, those means for characteristic evaluation are further provided in the examples of the present invention. In the main steps, an air electrode material is coated on the electrolyte membrane of a proton conductor single cell with an anode support, hydrogen gas containing 3% water vapor is supplied to the anode side, and air containing 3% water vapor is supplied to the air electrode side. For the single cell, cycle stability measurement is performed, that is, by applying a current of ±0.5 Acm -2 a reversible proton ceramic electrochemical cell with an anode support is alternately and repeatedly operated in a fuel cell mode and an electrolytic cell mode, respectively, and further, the electrochemical stability of the air electrode is evaluated.

[0041] In the following examples, PBC is used as a comparative sample, and its components are PrBaCo2O 6-δ and its manufacturing process is the same as that of the examples.

[0042] Example 1 In this example, a manufacturing method for PrBa 0.9 Cs 0.1 Co2O 6-δ which is the air electrode material of the reversible proton ceramic electrochemical cell with an anode support is provided, and the specific steps are as follows.

[0043] (1) As a stoichiometric ratio, praseodymium nitrate, barium nitrate, cesium nitrate and cobalt nitrate were sequentially added to a deionized aqueous solution in the stoichiometric ratio of PrBa 0.9 Cs 0.1 Co2O 6-δ (PBCsC). Then, citric acid was added in an amount 1.5 times the number of moles of metal ions, and ethylenediaminetetraacetic acid was added in an amount 1 time the number of moles of metal ions. Here, praseodymium nitrate, barium nitrate, cesium nitrate, cobalt nitrate, citric acid and ethylenediaminetetraacetic acid were obtained from the homepage of Aladdin Chemical Reagents.

[0044] (2) After adding a complexing agent to the solution containing dissolved metal ions, ammonia water was added to adjust the pH to 7-8, and then the mixture was heated and stirred under magnetic stirring conditions until the water evaporated and the mixture became dry, thereby obtaining a gel-like substance.

[0045] (3) The gel-like substance was placed in a forced-air oven and dried at 250°C for 2 hours to obtain a bulky, porous precursor.

[0046] (4) The precursor is placed in a high-temperature muffle furnace and calcined at 1000°C for 2 hours to obtain the desired air electrode material powder, PrBa 0.9 Cs 0.1 Ho2O 6-δ We obtained (denoted as PBCsC), where 0.1 ≤ δ ≤ 0.3.

[0047] Example 2 In this example, the PrBa provided in Example 1 0.9 Cs 0.1 Ho2O 6-δ We provide a reversible proton ceramic electrochemical cell with anode support of Ni-BZCYYb1711|transition layer Ni-BZCYYb1711|BZCYYb1711|PBCsC, fabricated with (PBCsC) as the air electrode of the cell, specifically comprising the following steps:

[0048] (1) Preparation of electrolyte layer slurry: 3 g of BZCYYb1711 powder, 0.1 g of fish oil dispersant, 0.8 g of anhydrous ethanol, and 0.8 g of butyl acetate were uniformly mixed to obtain a BZCYYb1711 electrolyte layer slurry. Preparation of transition layer slurry: 1.2 g of BZCYYb1711 powder, 1.8 g of nano-nickel oxide, 0.3 g of graphite, 0.1 g of fish oil dispersant, 0.75 g of anhydrous ethanol, and 0.75 g of butyl acetate were uniformly mixed to obtain a Ni-BZCYYb1711 transition layer slurry. Preparation of anode support layer slurry: 10 g of BZCYYb1711, 15 g of nickel oxide, 1.5 g of graphite, 1 g of fish oil dispersant, 3 g of anhydrous ethanol, and 3 g of butyl acetate were uniformly mixed to obtain an anode slurry. Each of the above slurries was placed into a drum-type ball mill and ground in the ball mill for 30 to 40 hours.

[0049] (2) The electrolyte slurry, transition layer slurry, and anode slurry, which were ball-milled and blended, were sequentially cast onto a polymer film which is a PET (polyethylene terephthalate) release film. The co-cast electrolyte layer-transition layer-anode support layer film was then air-dried for 12 hours. After that, several 15 mm diameter sheets were cut using a 15 mm diameter molding die, and these were placed in a muffle furnace and degreased at 600°C for 2 hours. Finally, the degreased sheets were placed in a high-temperature muffle furnace and fired at 1450°C for 5 hours to obtain the desired anode-supported half-cell. The anode-supported half-cell produced here includes a BZCYYb1711 electrolyte layer (thickness 7-9 μm), a Ni-BZCYYb1711 transition layer (thickness 30 μm), and a Ni-BZCYYb1711 anode support layer (thickness 600-700 μm).

[0050] (3) 1 g of PrBa air electrode powder prepared in Example 1 0.9 Cs 0.1 Ho2O 6-δ Then, 0.6 g of terpineol was weighed and uniformly mixed to obtain the desired air electrode slurry.

[0051] (4) After applying the manufactured air electrode slurry onto the electrolyte membrane of the half-cell, it was placed in an oven at 70°C. After the cathode slurry dried, the assembled whole cell was fired in a high-temperature muffle furnace at 950°C for 2 hours and used to measure the electrochemical performance in FC and EC modes.

[0052] Results of the characteristic evaluation 1. Characterization using XRD Figure 1 is PrBa 0.9 Cs 0.1 Ho2O 6-δThis is a refined XRD pattern obtained after calcining (PBCsC) powder at 1000°C for 2 hours, showing that the synthesized PBCsC exhibits a single double perovskite phase structure. In addition, the XRD refinement results indicate that the synthesized PBCsC has a tetragonal layered perovskite structure with lattice constants a=b=3.9045Å and c=7.6572Å (refinement parameter: GOF=2.13).

[0053] Figure 2 shows the chemical compatibility between the synthesized air electrode material PBCsC and the electrolyte BZCYYb1711 powder. As can be seen from the figure, even after mixing PBCsC and BZCYYb1711 and firing them in a high-temperature muffle furnace at 950°C for 2 hours, no chemical reaction occurred, indicating that the PBCsC material and the BZCYYb1711 powder have good chemical compatibility.

[0054] Figure 3 is PrBa 0.9 Cs 0.1 Ho2O 6-δ This is the XRD pattern of (PBCsC) powder after treatment at 600°C in air containing 30% water vapor for 10 hours. Here, the main peak of the XRD pattern of PBCsC after treatment is clearly shifted to the lower angle side, which is thought to be due to the expansion of the grid as water vapor penetrates it.

[0055] Figure 4 is PrBa 0.9 Cs 0.1 Ho2O 6-δ This is the high-temperature in situ XRD pattern of (PBCsC) powder. As can be seen from the figure, in measurements where PBCsC powder was continuously heated from 100 to 700°C (with a holding time of 1 hour at each temperature), no impurity phase was formed, indicating that PBCsC oxide exhibits good phase structure stability and chemical stability at high temperatures. In high-temperature in situ XRD measurements of PBCsC oxide, as the measurement temperature increases, the main peak of PBCsC shifts to the lower angle side, which is thought to be due to lattice expansion with increasing temperature.

[0056] 2. Characterization by X-ray photoelectron spectroscopy (XPS) According to the fitting data, after some of the Ba elements at the A site in PBC are replaced by Cs, the proportion of high-valence states of Pr (Figure 5(a)) and Co (Figure 5(b)) further increases in order for the material to maintain its electrical neutrality. As shown in Figure 5(a), Pr in PBC 4+ While the content of is 37.9%, Pr in PBCsC 4+ The content of increased to 41.1%. As shown in Figure 5(b), the Co element also showed a similar trend of change. In PBC, Co 3+ and Co 4+ The content of Pr and Co was 36.7% and 35.0%, respectively, but in PBCsC, their content increased to 41.8% and 43.5%, respectively. The XPS results indicate that doping PBC with Cs increases the content of high-valence cations of Pr and Co. The corresponding O 1s XPS fitting data for PBC and PBCsC are shown in Figure 6(a, b). Here, the O 1s of PBC and PBCsC can be divided into four dependent peaks. The dependent peaks with binding energies near 528.3, 530.0, 531.4, and 533.4 eV are lattice oxygen (O) lat ), high oxygen dioxide (O - / O2 2- ), adsorbed oxygen (O ads ) and oxygen (OH) in a hydroxyl environment - ) is involved. Here, O - / O2 2 and O lat The ratio of PBCsC reflected the oxygen vacancy content, with the ratios being 1.49 and 2.03, respectively. Furthermore, the O in oxides... - / O2 2- The proportion of this is generally considered to play an important role in the ORR process.

[0057] 3. Assessment of relaxation characteristics Figure 7 shows the surface exchange coefficient k of PBCsC and PBC at measurement temperatures of 550-650°C. * chemand bulk diffusion coefficient D * chem This demonstrates the following. According to the calculation, the surface exchange coefficient of PBCsC at a measurement temperature of 650°C is 7.98 × 10⁻⁶. -4 cms -1 The surface exchange coefficient of PBC measured under the same conditions is (2.31 × 10⁻⁶). -4 cms -1 It was higher than k. * chem The increase in value indicates that the PBCsC air electrode has relatively fast oxygen surface exchange kinetics, which accelerates the progress of the ORR reaction. * chem The results also show a similar trend. Under measurement conditions of 650°C, the D of PBC and PBCsC * chem The values ​​are 2.64 × 10 -5 and 9.01 × 10 -5 cm 2 s -1 It was. PBCsC's D * chem A higher value indicates that PBCsC has better oxygen diffusion kinetics. Therefore, the increase in electrocatalytic activity of the PBCsC air electrode is thought to be due to the doping of the A-site dopant (Cs), which creates more oxygen vacancies and improves surface exchange kinetics.

[0058] 4. Study of electrochemical impedance and stability First, the electrocatalytic activity of the PBCsC air electrode was investigated by measuring the area resistivity of a symmetric cell supported by BZCYYb1711 in humid air (3% H2O) at 700-500°C. As shown in Figure 8(a), the area resistivity values ​​of the PBCsC air electrode were 0.067, 0.184, 0.276, 0.575, and 1.588 Ωcm at 700, 650, 600, 550, and 500°C, respectively. 2 The electrocatalytic activity of the PBC air electrode is shown in Figure 8(b). Under the same measurement conditions, the area resistivity of the PBC air electrode was 0.113, 0.258, 0.372, 0.977, and 2.443 Ωcm at 700, 650, 600, 550, and 500°C, respectively.2 It has reached this level. Compared to PBC air electrodes, PBCsC air electrodes have relatively high electrocatalytic activity.

[0059] Figure 9 shows the stability of PBCsC and PBC in humid air (3% H2O). When exposed to humid air, the area resistivity of the PBC air electrode increased significantly with increasing measurement time. On the other hand, under the same measurement conditions, the area resistivity of the PBCsC air electrode showed better stability. Based on the above analysis, a symmetrical battery with a PBCsC air electrode has good stability and relatively high electrocatalytic activity.

[0060] 7. Characterization using Fourier transform infrared spectroscopy (FTIR) Figure 10 shows the Fourier transform infrared spectra of PBCsC and PBC air electrodes after treatment at 600°C with humid air containing 30% water vapor for 50 hours. FTIR measurements can identify the signal value of hydroxyl groups in oxides, with a characteristic peak at 3400–3800 cm⁻¹. -1 It appears within the specified range. The measurement results show that the peak intensity of the hydroxyl group in 30% steam-treated PBCsC is slightly higher than that of PBC oxide, indicating that PBCsC exhibits better hydration behavior.

[0061] 8. Measurement of electrochemical properties Using the battery manufactured in Example 2, the electrochemical power density was measured in fuel cell mode (FC mode), and the current density was measured in electrolysis mode (EC mode). Figure 11 shows the results when the entire battery according to the present invention, with PBCsC as the air electrode, was measured in fuel cell mode, with humidified hydrogen gas supplied to the anode side and the atmosphere on the air electrode side being air. The power density measured in the range of 650 to 500°C was 1.66 Wcm². -2 , 1.19Wcm -2 , 0.72Wcm -2 , and 0.41 Wcm -2 That was the case.

[0062] Figure 12 shows the IV curve when a single cell (Ni-BZCYYb1711||BZCYYb1711||PBCsC) manufactured using PBCsC as the air electrode and Ni-BZCYYb1711 as the fuel electrode support is measured in EC mode (humidified hydrogen gas is supplied to the anode side and humidified air is supplied to the oxygen electrode side) within the range of 650 to 500°C. Here, the electrolytic cell with the PBCsC air electrode also shows superior electrolytic performance, and the current density at a voltage of 1.3V is -2.85 Acm² at 650, 600, 550, and 500°C, respectively. -2 -1.48Acm -2 -0.71Acm -2 , and -0.31Acm -2 That was the case.

[0063] 9. Stability and cycle testing of single cells Figure 13 shows the PBCsC air electrode at 650°C with a pressure of 0.5 A cm. -2 This shows the long-term stability of the battery when operated for 170 hours in FC mode at the given current density. Furthermore, because moist air is present in the R-PCEC air electrode chamber, the resistance of the air electrode to vapor is extremely important for the battery's stability. All batteries using PBCsC as the air electrode showed good stability in the electrolysis mode using moist air (3% H2O) as the oxidizing agent, at -0.5 Acm². -2 It operated stably for 200 hours at 650°C. ±0.5Acm -2 A cycle test was also performed at a temperature of 600°C, switching between FC mode and EC mode at 2-hour intervals (Figure 14). The battery with PBCsC air electrodes showed good stability during an 80-hour reversible operating period.

[0064] 10. Measurement of Faraday efficiency and hydrogen production rate

[0065] Faraday efficiency is crucial for hydrogen production in the R-PCEC electrochemical process, and is defined as the ratio of the actual H2 production rate (detected by gas chromatography) to the theoretical H2 production rate (calculated from the applied current). Figures 15 and 16 show the Faraday efficiency and hydrogen production rate at different current densities and in humid air (30% vapor concentration) at 600°C. As shown in Figure 15, the cell was subjected to -0.5, -0.75, and -1.0 Acm². -2 When applied at different current densities, the Faraday efficiency decreased from 85.37% to 60.86% and 48.88%. Furthermore, as shown in Figure 16, the current densities of -0.5, -0.75, and -1.0 Acm² were also reduced. -2 In this case, the corresponding H2 generation rate increased from 2.98 to 3.18 and 3.41.

[0066] The above embodiments are merely for illustrative purposes and not to limit the technical proposals of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art will understand that the technical proposals described in each of the above embodiments may be modified or some of their technical features may be replaced by equivalent substitutions, and that such modifications or substitutions will not cause the spirit of the corresponding technical proposals to deviate from the idea and scope of the technical proposals in each embodiment of the present invention.

Claims

1. The general formula is PrBa １－ｘ Cs ｘ Co ２ O ６－δ Here, δ is the oxygen vacancy content, and the range of x is 0.01 to 0.

15. A double perovskite material characterized by the following features.

2. The range of x is 0.05 to 0.

125. The double perovskite material according to claim 1, characterized in that...

3. The double perovskite material has a tetragonal layered perovskite structure, where the lattice constants are a = 3.9045 ± 0.1 Å, b = 3.9045 ± 0.1 Å, and c = 7.6572 ± 0.1 Å. The double perovskite material according to claim 1, characterized in that...

4. The general formula is PrBa ０．９ Cs ０．１ Co ２ O ６－δ That is The double perovskite material according to claim 1, characterized in that...

5. (1) Dissolve praseodymium nitrate, barium nitrate, cesium nitrate, and cobalt nitrate in water to obtain a mixture, then mix the mixture with ethylenediaminetetraacetic acid, citric acid, and ammonia water, adjust the pH to 7-8 to obtain a mixed solution, and (2) Heat the mixed solution until it becomes gel-like, perform high-temperature treatment at 200-250°C to obtain a precursor, and calcine the precursor. A method for producing a double perovskite material according to any one of claims 1 to 4, characterized by including the following:

6. In step (1), the molar ratio of the metal element, ethylenediaminetetraacetic acid, and citric acid is 0.5 to 1.5:0.5 to 1.5:1 to 2, where the metal element is the sum of Pr, Ba, Cs, and Co. A method for producing a double perovskite material according to claim 5, characterized in that

7. In step (2), the heating temperature of the mixed solution is 80 to 100°C, and / or the high-temperature treatment time is 2 to 6 hours, and / or the firing temperature is 950 to 1050°C, and the firing time is 2 to 4 hours. A method for producing a double perovskite material according to claim 5, characterized in that

8. This involves the use of double perovskite materials as air electrodes in reversible proton ceramic electrochemical cells. The use of the double perovskite material according to any one of claims 1 to 4, characterized in that

9. The material comprises sequentially connected anode support layers, an electrolyte, and an air electrode, wherein the air electrode is manufactured from the double perovskite material described in claim 1. A reversible proton ceramic electrochemical battery characterized by the following features.

10. The material of the electrolyte contains BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ where δ is the oxygen vacancy content, and / or The material of the anode support layer contains NiO and BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ This includes NiO and BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ The mass ratio of is 5.5–6.5:3.5–4.5, and / or The reversible proton ceramic electrochemical battery further includes a transition layer, the transition layer being provided between the anode support layer and the electrolyte. A reversible proton ceramic electrochemical cell according to claim 9, characterized in that...

11. The transition layer contains NiO and BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ This includes NiO and BaZr ０．１ Ce ０．７ Y ０．１ Yb ０．１ O ３－δ The mass ratio is 5.5–6.5:3.5–4.

5. A reversible proton ceramic electrochemical battery according to claim 10, characterized in that...

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