A B-site multi-element doped perovskite material and its application in proton ceramic electrolyzers and fuel cells

Abstract

This invention relates to a B-site multi-element doped perovskite material and its application in proton ceramic electrolyzers and fuel cells, as well as a method for characterizing hydration reaction activity. The perovskite material is a B-site multi-element doped BaCo... 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3‑δ (BCZTZICM) exhibits good hydration reactivity. When applied to a proton ceramic electrolyzer (PCEC), it can achieve an efficiency of 1.84 A cm⁻¹ at 650 °C and 1.3 V. ‑2 The electrolysis current has excellent electrochemical catalytic activity, and it can improve the electrocatalytic reaction activity of the material in fuel cells and reduce the thermal expansion coefficient of the material.

Description

Technical Field

[0001] This invention relates to a B-site multi-element doped perovskite material and its application in proton ceramic electrolyzers and fuel cells, belonging to the field of new energy materials technology. Background Technology

[0002] Currently, due to the continuous deterioration of global environmental and climate problems and the escalating energy crisis, the development of clean and green energy has become an important research goal. Traditional fossil fuels generate large amounts of pollutants during use, causing severe environmental problems. Hydrogen energy, as an alternative, still mainly relies on coal and natural gas reforming for hydrogen production, failing to achieve zero carbon emissions. In contrast, water electrolysis for hydrogen production uses water and electricity, both renewable energy sources, and the process does not produce carbon emissions, thus attracting widespread global attention. Among these methods, solid oxide electrolyzers have become an excellent choice for industrialization due to their extremely high energy conversion efficiency and low-cost, non-precious metal electrodes. However, their extremely high operating temperature (800-1000℃) severely hinders their large-scale industrial development. Therefore, to improve the stability of electrolyzers and reduce material costs, lower operating temperatures (400-700℃) are the trend for their development. As the operating temperature decreases, the conductivity of oxygen ion conductor electrolytes rapidly declines, highlighting the superiority of proton conductors. Compared to oxygen ion conductors, proton conductor solid oxide electrolyzers offer advantages such as: protons have smaller ionic radii, resulting in lower activation energies during transport; proton transference number increases with decreasing temperature; and water introduced at the air electrode does not dilute hydrogen, reducing the cost of subsequent hydrogen purification processes. However, the oxygen evolution reaction at the air electrode is a typical four-electron migration process, with a reaction energy barrier much higher than the two-electron migration hydrogen evolution reaction at the hydrogen electrode. Furthermore, since water vapor is introduced into the proton conductor via the air electrode, it must first be adsorbed at the air electrode before the oxygen evolution reaction can proceed, making the reaction more complex. Therefore, developing air electrode materials for proton ceramic electrolyzers (PCECs) is a breakthrough direction in electrolyzer research.

[0003] Building on this, the PCEC air electrode has evolved from the earlier oxygen ion (O) electrode. 2- ) electron (e - Hybrid conductors have evolved to today's form with oxygen ions (O2). 2- ), proton (H) +It is a three-phase conductor with good electron conduction capabilities. However, the current mainstream PCEC cathode still relies mainly on oxygen ion transport, with weak proton transport capabilities. According to current research, water vapor mainly combines with oxygen vacancies in the air electrode to form proton defects, thereby completing the migration of protons in the air electrode. Therefore, optimizing the hydration capacity of the air electrode is an important means to increase the concentration of proton defects and thus increase the electrolytic current density of the electrolytic cell.

[0004] Furthermore, fuel cells have attracted widespread attention due to their durability, environmental friendliness, high energy conversion efficiency, and safe operation. Solid oxide fuel cells are considered highly promising energy conversion devices, capable of efficiently converting chemical energy into electrical energy and solving the problem of energy utilization efficiency. Compared to traditional solid oxide fuel cells (SOFCs) that primarily rely on oxygen ion conduction, proton ceramic fuel cells (PCFCs) require lower activation energy for proton conduction and can operate at medium to low temperatures (500-650℃), thus avoiding problems such as high operating costs, difficult equipment sealing, and poor durability caused by high temperatures. PCFCs are energy conversion devices that generate electricity based on proton conduction and can utilize renewable energy sources or industrial hydrocarbon fuel exhaust gases to achieve efficient power generation.

[0005] However, one of the technical challenges of PCFC is the insufficient catalytic activity of the oxygen reduction reaction (ORR) at the cathode as the temperature decreases. Furthermore, the high-performance cathodes of current high-performance PCFCs are mainly made of Co-based materials, whose high coefficient of thermal expansion leads to thermo-mechanical instability between the electrode and the electrolyte, which is a major bottleneck for the commercialization of PCFCs. Therefore, developing cathodes with high electrocatalytic activity and low coefficient of thermal expansion is of great significance for PCFC.

[0006] In recent years, many researchers have developed a large number of high-performance cathodes for SOFCs by exploring different elemental doping methods, as well as co-doping and even multi-component doping. However, the underlying mechanisms based on elemental co-doping or multi-component doping remain controversial. Zhou et al. synthesized SrCo 0.8 Nb 0.2 O 3-δ SrCo 0.8 Ta 0.2 O 3-δ SrCo 0.8 Nb 0.1 Ta 0.1 O 3-δThis study explored the main reasons for the improvement of cathode performance in solid oxide fuel cells (SOFCs) through experiments and theoretical calculations. The research proposes that co-doping helps promote the uniform distribution of Co, reduces the accumulation of oxygen vacancies to achieve rapid oxygen ion reduction, and also facilitates the reduction of the activation energy of the oxygen reduction reaction. This allows the material to perform well at 500℃ based on the oxygen ion conductor electrolyte Gd... 0.1 Ce 0.9 O 1.9 A 0.1 Ωcm was obtained on a symmetric cell (GDC). 2 Area ratio impedance (ASR). (Non-Patent Document 1)

[0007] Take La 0.7 Sr 0.3 (Co,Cr,Fe,Mn,Ni)O 3-δ As an electrode, La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-δ The polarization impedance of the symmetrical cell with electrolyte is 0.126 Ωcm. -2 When used as an air electrode in a fuel cell, the maximum power density of a single cell at 900°C reached 550 mW / cm². -2 This fully demonstrates the possibility of using high-entropy perovskite as an air electrode in SOFC (Non-Patent Literature 2). Meanwhile, doping with multiple B-site elements modulates the entropy value of the material, thereby improving its stability, but inevitably reducing the electrochemical activity of the SOFC air electrode material.

[0008] Non-patent literature 1: Wenhuai Li, Mengran Li, Wei Zhou, et al. High CationicDispersity Boosted Oxygen Reduction Reactivity in Multi-Element DopedPerovskites[J]. Advanced Functional Materials, 2022, 2210496. (10.1002 / adfm.202210496)

[0009] Non-patent literature 2: J,Olszewska A,Falkenstein A,et al.An InnovativeApproach to Design SOFC Air Electrode Materials:High Entropy La 1-x Sr x(Co,Cr,Fe,Mn,Ni)O 3-δ (x=0,0.1,0.2,0.3)Perovskites Synthesized by the Sol-Gel Method[J]. Journal of Materials Chemistry A, 2020, 8, 24455. (10.1039 / D0TA06356H). Summary of the Invention

[0010] This invention provides a high-performance proton conductor solid oxide air electrode material BCZTZICM for electrolytic cells, its preparation method, and its applications. This material enhances hydration reaction activity, thereby improving the performance of the electrolytic cell. The prepared material has the molecular formula BaCo. 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ The air electrode possesses excellent hydration reactivity and superior physical / chemical adsorption capacity for water vapor, making it suitable for use in medium- and low-temperature proton conductor solid oxide electrolyzers. Furthermore, when applied to proton ceramic fuel cells (PCFCs), this material can improve the oxygen reduction (ORR) activity of the cathode material and reduce its coefficient of thermal expansion (TEC).

[0011] A proton conductor solid oxide material with the general formula ABO 3-δ The perovskite oxide material has the molecular formula: BaCo x (Zr a Ti b Zn c In d Cu e Mo f ) y O 3-δ (BCZTZICM), where δ is the content of oxygen vacancies; and x+y=1 and a+b+c+d+e+f=1.

[0012] The molecular formula is: BaCo 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ .

[0013] The above-mentioned method for preparing the air electrode material of the proton conductor solid oxide electrolytic cell is to prepare it by sol-gel method according to stoichiometry.

[0014] The sol-gel method includes the following steps: first, tetrabutyl titanate and ammonium molybdate are heated with deionized water and citric acid monohydrate until clear and transparent, and then they are prepared by sol-gel method with barium nitrate, cobalt nitrate, zirconium nitrate, zinc nitrate, indium nitrate and copper nitrate according to the stoichiometric ratio in the molecular formula.

[0015] The process includes the following steps: First, dissolve tetrabutyl titanate and ammonium molybdate in deionized water and citric acid monohydrate by heating until clear and transparent. Then, add barium nitrate, cobalt nitrate, zinc nitrate, zirconium nitrate, copper nitrate, and indium nitrate to dissolve and heat while stirring. Add ethylenediaminetetraacetic acid, and then add ammonia dropwise until the pH of the solution is between 7 and 8. Under heating and stirring conditions, allow the water to evaporate to obtain a gel-like substance. Place the gel-like substance in an oven to dry, and obtain the precursor of the air electrode material. Then, place the precursor in a muffle furnace for calcination to obtain the desired air electrode material for the electrolytic cell.

[0016] The total molar ratio of ethylenediaminetetraacetic acid and citric acid to Ba, Co, Zr, Ti, Zn, In, Cu, and Mo is 2:0.5-1.5:0.5-1.5.

[0017] The drying process is carried out at 160-200℃ for 5-8 hours.

[0018] The calcination parameters are 1000℃ for 1-10 hours.

[0019] The aforementioned solid oxide materials are used as proton conductors in water electrolysis or in fuel cells.

[0020] The electrolyte used is BaZr. 0.1 Ce 0.7 Y 0.1 Yb 0.1 O3.

[0021] The anode material uses NiO and BaZr. 0.1 Ce 0.7 Y 0.1 Yb 0.1 A composite anode composed of O3(BZCYYb).

[0022] The mass ratio of NiO to electrolyte in the composite anode is (3-5):(6-7).

[0023] A method for characterizing the hydration reaction activity of an air electrode in a solid oxide electrolytic cell includes the following steps:

[0024] Air electrode material powder with uniform particle size was placed in a tube furnace and subjected to dry air and wet air treatment at the operating temperature, and then quenched as a characterization material.

[0025] The ionic valence state of the characterizing material was determined to obtain the changes in ionic valence state during dry and humid air treatment.

[0026] It was determined that materials with greater variation have better hydration reactivity.

[0027] The air electrode material powder is granulated to ensure that the particle size is consistent.

[0028] The treatment is carried out at a temperature of 500-700℃ for 1-5 hours.

[0029] The volume fraction of water vapor in moist air is 1-40%.

[0030] The quenching method is air quenching, which involves taking the material out and rapidly cooling it in the air.

[0031] The valence state of ions was determined by X-ray absorption spectroscopy.

[0032] Beneficial effects

[0033] Hydration reactivity tests showed that the valence changes of variable ions in BCZTZICM, BCFZY, and BSCF were 0.056, 0.049, and 0.043, respectively, indicating that BCZTZICM has stronger hydration reactivity.

[0034] BaCo solid oxide electrolytic cell air electrode material prepared by sol-gel method 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ (BCZTZICM). It exhibits high electrolytic current density; single cells prepared using Ni-BZCYYb as the anode support achieve electrolytic current densities of 1.8 A / cm³ at 1.3 V and temperatures of 650℃, 600℃, 550℃, and 500℃. -2 1.4A cm -2 0.9Acm -2 0.6Acm -2 This is higher than the 1.3 A cm⁻¹ achieved by BSCF and BCFZY at the corresponding temperatures. -2 1.0Acm -2 0.7Acm -2 0.5A cm -2 .

[0035] This invention improves the ORR activity and reduces the coefficient of thermal expansion of PCFC cathode materials. Zr, Ti, Zn, In, Cu, and Mo are incorporated into traditional BaCoO in a one-step sol-gel process. 3-δ At the B site, the thermal expansion behavior of Co ions at the B site and the stretching vibration of the metal-oxygen bond energy between the B-site element and the O element are more easily directly regulated, thereby enhancing the ORR activity of the BCZTZICM cathode material in PCFC and reducing its thermal expansion coefficient to 17.67 × 10⁻⁶. -6 K -1 Furthermore, thanks to the reduction in the coefficient of thermal expansion, the structural stability of the BCZTZICM cathode has been significantly improved, resulting in good performance of the single cell in long-term stability tests.

[0036] BCZTZICM, as an excellent air electrode material, achieved peak power densities of 1.3 W / cm² at 650℃, 600℃, 550℃, and 500℃ in proton conductor fuel cell tests. -2 0.88W cm -2 0.68W cm -2 0.49W cm -2 . Attached Figure Description

[0037] Figure 1 This is the selected area electron diffraction pattern of BCZTZICM;

[0038] Figure 2 a) Electrolyte chemical compatibility test results of BCZTZICM and BZCYYb; b) Rietveld refined XRD pattern of BCZTZICM material at room temperature;

[0039] Figure 3 This is a high-resolution transmission electron microscope (HRTEM) image by BCZTZICM;

[0040] Figure 4 It is a BCZTZICM EDX-mapping image.

[0041] Figure 5 These are the XRD patterns of the BCZTZICM sample obtained at different temperatures;

[0042] Figure 6 The XRD patterns of BCZTZICM powder samples before and after calcination at 600℃ for 200 hours are compared.

[0043] Figure 7 These are the H2O-TPD diagrams of BCZTZICM, BSCF, and BCFZY;

[0044] Figure 8 These are in-situ infrared spectra of BCZTZICM, BSCF, and BCFZY for water vapor adsorption at 600℃.

[0045] Figure 9 The X-ray near-edge structures of variable valence ions BCZTZICM, BSCF, and BCFZY before and after water flow at 600℃, and the valence state changes calculated from them;

[0046] Figure 9g It is the change in valence state of a variable-valence element in a single sample;

[0047] Figure 10a The image shows the IV curves of an electrolytic cell (Ni-BZCYYb|BZCYYb|BCZTZICM) prepared with BCZTZICM as the air electrode and Ni-BZCYYb as the anode support, tested in the range of 500-650℃.

[0048] Figure 10b and Figure 10c The images show the IV curves of a single cell (Ni-BZCYYb|BZCYYb|BSCF / BCFZY) prepared with BSCF and BCFZY as air electrodes and Ni-BZCYYb as the anode support, tested at 500-650℃.

[0049] Figure 11 This is a stability test diagram of an electrolytic cell using BCZTZICM as the air electrode.

[0050] Figure 12 This is a comparison of the mass loss of BCZTZICM, BCFZY, and BSCF from room temperature to 1000℃.

[0051] Figure 13 This is a comparison of the thermal expansion coefficients of BCZTZICM, BCFZY, BSCF, and electrolyte BZCYYb;

[0052] Figure 14 These are the XANES curves of BCZTZICM, BCFZY, and BSCF at room temperature and 600℃, and the valence state changes of variable valence ions calculated from the XANES curves.

[0053] Figure 15 This is a comparison chart of the O1s binding energy of XPS for BCZTZICM, BCFZY, and BSCF.

[0054] Figure 16 The Arrhenius diagrams of ASRs obtained on symmetrical cells supported by BZCYYb under humid air conditions in the range of 500-700℃, consisting of BCZTZICM, BCFZY, and BSCF.

[0055] Figure 17 The IVP curves of a Ni-BZCYYb|BZCYYb|BCZTZICM single cell fuel cell within the 500-650℃ range are shown.

[0056] Figure 18 This is the stability test curve of the BCZTZICM single cell fuel cell at 550℃;

[0057] Figure 19 Comparison of XRD phase structures of single-element doped samples and hexa-element doped BCZTZICM;

[0058] Figure 20 Comparison of XRD phase structures of binary and tetra-doped samples with hexa-doped BCZTZICM. Detailed Implementation

[0059] This invention provides a perovskite hybrid conductor, the general formula of which is ABO. 3-δ The molecular formula is: BaCo 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ (BCZTZICM), where δ represents the oxygen vacancy content.

[0060] The design concept of the above-mentioned perovskite hybrid conductor is: BCZTZICM uses BaCoO 3-δ As a parent material, it possesses excellent oxygen reduction activity; however, its coplanar hexagonal phase structure weakens intracrystalline charge and ion migration. Here, we constructed BaCo by micro-doping with multiple elements at the B site. 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6Mo 1 / 6 ) 0.2 O 3-δ(BCZTZICM). Multi-element doping transforms its structure into a cubic perovskite phase, and the multi-element doping results in a more uniform distribution of oxygen vacancies, thus achieving excellent proton / oxygen ion migration activity. Furthermore, the high Co content ensures excellent electrocatalytic activity. Here, the oxygen ion / electron conductor BSCF, with the same phase structure and excellent oxygen evolution reaction activity, and the classic proton / oxygen ion / electron three-phase conductor BCFZY air electrode are studied as a comparison. The above materials can be prepared according to the composition ratio using the sol-gel method.

[0061] B-site multi-element doping not only effectively increases the material's entropy value but also reduces its thermal expansion coefficient, thereby improving its ORR activity and operational durability in fuel cells. Within the 300-800℃ range, BCZTZICM exhibits an entropy value of only 17.67 × 10⁻⁶. -6 K -1 Its coefficient of thermal expansion is much lower than that of BSCF and BCFZY, which are 23-25×10⁻⁶. -6 K -1 The coefficient of thermal expansion. In single-cell operation, the BCZTZICM electrode achieved a maximum peak power density of 1.3 W / cm² at 650 °C. -2 The BCZTZICM electrode exhibits excellent durability during long-term single-cell operation. This invention develops a high-performance proton ceramic fuel cell cathode material and its preparation method, significantly improving the electrochemical performance of proton conductor fuel cells.

[0062] Furthermore, current characterization methods for the hydration reactivity of the air electrode in a proton conductor electrolyzer mainly focus on H2O-TPD and Karl Fischer water content titration, which cannot significantly characterize the hydration reaction process and the formation of intermediates. To characterize the hydration reactivity of the aforementioned materials, this invention also provides a characterization testing method. This is mainly based on the following equation:

[0063]

[0064] in Represents lattice oxygen, For oxygen vacancies, It is a proton defect. Since proton defects occupy oxygen sites and form bonds with surrounding metal ions, the content of proton defects can be obtained by detecting changes in the valence state of metal ions.

[0065] Example 1

[0066] This embodiment provides a BaCo proton conductor solid oxide electrolytic cell air electrode material. 0.8 (Zr 1 / 6 Ti 1 / 6ZnIn 1 / 6Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ The preparation method of [the substance] is as follows:

[0067] (1) Weigh 0.5729g tetrabutyl titanate, 0.2972g ammonium molybdate heptahydrate, and 42.028g citric acid monohydrate, and dissolve them in an appropriate amount of deionized water. Then add 13.1327g barium nitrate, 11.8185g cobalt nitrate, 0.7155g zirconium nitrate, 0.5008g zinc nitrate, 0.4067g copper nitrate, and 0.5014g indium nitrate. Weigh 29.224g ethylenediaminetetraacetic acid as a complexing agent according to the molar ratio of ethylenediaminetetraacetic acid:citric acid monohydrate:metal ions = 1:2:1, and add an appropriate amount of deionized water.

[0068] (2) Add the obtained complexing agent to the dissolved metal ion solution, and then add an appropriate amount of ammonia water to adjust the pH range of the solution to 7-8. Then heat and stir until the water evaporates to obtain a gel-like substance.

[0069] (3) The gelatinous substance was placed in an oven at 180°C to remove moisture and obtain the precursor.

[0070] (4) The obtained precursor was placed in a muffle furnace at 1000℃ and calcined for 5 hours to finally obtain the electrode powder.

[0071] Comparative experiment

[0072] Mono-, binary, and quaternary B-site doped BaCoO were prepared respectively. 3-δ The perovskite-based air electrode materials, with mono-doped molecular formulas, were prepared using a method similar to that of Example 1, except that the corresponding elements were not added to the metal salts obtained in the sol-gel method. XRD characterization data showed that these materials partially contained impurity phases, while the materials prepared in Example 1 did not contain impurity phases.

[0073] Example 2: In-situ Test of Chemisorption Capacity of Air Electrode

[0074] (1) Weigh 0.03g of the air electrode powder BaCo obtained in Example 1. 0.8 (Zr 1 / 6 Ti 1 / 6 ZnIn 1 / 6 Cu 1 / 6Mo 1 / 6 ) 0.2 O 3-δ Mix the potassium bromide powder with 3g in a mortar until homogeneous. Take 0.5g of the mixture and add it to a high-temperature in-situ testing platform. Heat the sample to 600℃ at 10℃ / min and dry for 30min to eliminate the influence of air and adsorbed water in the sample on the test.

[0075] (2) For samples under dry conditions, Fourier transform attenuated total reflectance infrared spectroscopy standard samples were used for initial state comparison. Then, air containing water vapor was introduced, and the 3200-3800 cm⁻¹ values ​​were continuously measured. -1 The intensity variation of the peak was measured by removing the water vapor and introducing dry air after 45 minutes, and the peak intensity was then tested again at 3200-3800 cm⁻¹. -1 The intensity changes of the peak segment indicate the removal of hydroxyl radicals.

[0076] Example 3: Preparation of Electrolytic Cell

[0077] (1) Weigh 0.35g of uniformly mixed NiO+BZCYYb hydrogen electrode powder and press it into a green blank under a pressure of 4mPa.

[0078] (2) Mix 1g of BZCYYb powder with 20ml of ethanol in a high-energy ball mill and mill at 400rpm for 1h to obtain an electrolyte slurry. Use a spraying equipment to uniformly spray it on one side of the hydrogen electrode. Stop spraying when the single piece of spraying reaches 0.015g and use a tablet press to make the electrolyte of the semi-electrolytic cell green body tightly bonded to the hydrogen electrode. Calcine at 1450℃ for 5h.

[0079] (3) Weigh 1g of the cathode powder BaCo obtained in Example 1. 0.8 (Zr 1 / 6 Ti 1 / 6 ZnIn 1 / 6 Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ 10 ml of isopropanol, 2 ml of ethylene glycol, and 0.8 ml of glycerol were poured into a high-energy ball mill and milled at 400 r / min for 30 min. The mixture was then transferred to a culture bottle using a pipette to obtain the desired cathode slurry.

[0080] (4) The prepared dry-pressed cell is placed on a heating table and preheated at 200°C. The prepared cathode slurry is uniformly sprayed onto the electrolyte surface of the dry-pressed cell under the push of inert gas using a spray gun. After the liquid has completely evaporated, the sprayed dry-pressed cell is placed in a high-temperature muffle furnace and calcined at 900°C for 2 hours to obtain the required symmetrical cell, which is used for testing the electrolysis of water by the cathode material in the temperature range of 500-650°C.

[0081] Example 4

[0082] This embodiment provides a BaCo... 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu1 / 6 Mo 1 / 6 ) 0.2 O 3-δ The specific steps for preparing and testing a symmetrical cell with electrodes are as follows:

[0083] (1) Weigh 1g of the electrode powder BaCo prepared in Example 1. 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6Mo 1 / 6 ) 0.2 O 3-δ The electrode slurry was obtained by ball milling in a high-energy ductile ink container with 10 mL of isopropanol, 2 mL of ethylene glycol, and 0.8 mL of glycerol for 30 min at 400 r / min.

[0084] (2) The prepared BZCYYb electrolyte sheet was placed on a heating stage at 150℃. The prepared electrode slurry was uniformly sprayed onto both sides of the electrolyte sheet using an inert gas and a spray gun. After the liquid had completely evaporated, the sprayed electrolyte sheet was placed in a high-temperature furnace at 1000℃ for 2 hours to obtain the desired symmetrical cell, which was then used to test the electrode polarization impedance in the temperature range of 500-700℃. The polarization impedances of the cell measured at 700-500℃ under 5% water pressure were 0.05 and 0.47 Ωcm, respectively. 2 .

[0085] Example 5

[0086] This embodiment provides a method for preparing and testing a single cell using BCZTZICM as the air electrode. The specific steps are as follows:

[0087] (1) Weigh 1g of the electrode powder BCZTZICM prepared in Example 1 into a high-energy spherical ink jar, and add 10mL of isopropanol, 2mL of ethylene glycol and 0.8mL of glycerol. After ball milling at 400r / min for 30min, the desired electrode slurry is obtained.

[0088] (2) The prepared NiO-BZCYYb single-cell electrode was placed on a heating stage at 150°C. The prepared electrode slurry was uniformly sprayed onto the electrolyte side surface using an inert gas and a spray gun. After the liquid completely evaporated, the sprayed electrolyte electrode was placed in a high-temperature furnace at 1000°C for 2 hours to obtain the desired single cell. This single cell was then used to test the fuel cell performance within a temperature range of 650-500°C. The peak power density measured in fuel cell mode at 650°C was 1.3 W / cm². -2 Characterization results

[0089] 1. Selected Area Electron Diffraction Characterization

[0090] Figure 1 The selected area electron diffraction pattern of BCZTZICM shows a typical cubic perovskite space group structure with [-1 1 0] crystal axes formed by the (001)(110)(111) crystal planes.

[0091] 2. Phase reaction test

[0092] Figure 2 Figure 'a' shows the XRD pattern of BCZTZICM and electrolyte BZCYYb mixed at a 1:1 mass ratio and calcined at 1000℃ for 2 hours. The XRD pattern after calcination did not show any new peaks compared to the original sample, indicating that no new phase was formed, demonstrating good chemical compatibility between BCZTZICM and BZCYYb. Figure 2 b is BaCo x (Zr a Ti b Zn c In d Cu e Mo f ) y O 3-δ (BCZTZICM) Cathode Material Rietveld Refined XRD Pattern at Room Temperature; The XRD pattern clearly shows that BCZTZICM powder has a cubic perovskite structure with space group Pm-3m and no additional peaks.

[0093] 3. Characterization by high-resolution transmission electron microscopy (HRTEM)

[0094] Figure 3 This is an HRTEM image of BCZTZICM. Multi-element doped BCZTZICM perovskite was studied by high-resolution TEM. Lattice fringes with spacings of 0.288 nm, 0.183 nm, and 0.236 nm were observed, corresponding to the (011), (120), and (111) crystal planes of BCZTZICM crystal, respectively. The image in the upper left corner is obtained by fast Fourier transform, and the

[211] crystal axis was confirmed by the 011, 120, and 111 crystal planes.

[0095] 4. EDX-mapping element distribution map

[0096] Figure 4 This is the EDX-mapping elemental distribution diagram of BCZTZICM. The EDX-mapping shows the uniformity of the overall distribution of Ba, Co, Zr, Ti, Zn, In, Cu, Mo and O elements, and the proportion of each atom shown in the spectrum is close to the stoichiometric proportion.

[0097] 5. High-temperature XRD characterization

[0098] Figure 5 These are XRD patterns of the BCZTZICM sample obtained from room temperature to high temperature. By testing the XRD patterns of the sample at different temperatures, it can be found that its high Co content did not cause a significant change in ionic radius leading to a phase structure transformation at high temperature. The right-hand image magnifies the main peak of its 011 crystal plane, and the slight leftward shift represents lattice expansion caused by the thermal reduction of Co ions.

[0099] 6. Characterization of thermal stability of phase structure

[0100] Figure 6 The XRD phase structure is before and after calcination at 600℃ for 200 hours. The phase structure did not change significantly before and after calcination, and no new peaks appeared, indicating that the phase structure is stable and can maintain a stable phase structure at the operating temperature.

[0101] 7. Characterization of water vapor physical adsorption capacity

[0102] Figure 7 This is a graph showing the physical adsorption capacity of BCZTZICM, BSCF, and BCFZY for water vapor. Equal masses of powder were subjected to water vapor treatment at 250℃ and then quenched, followed by a water vapor temperature-programmed desorption (H2O-TPD) test. The desorbed water vapor was detected by mass spectrometry. The graph shows that BCZTZICM exhibits excellent physical adsorption capacity for water vapor, indicating that its microstructure as an air electrode has advantages in the kinetics of the oxygen reduction reaction involving water vapor.

[0103] 8. Characterization of water vapor chemisorption capacity

[0104] Figure 8 These are the in-situ Fourier transform attenuated total reflectance infrared spectra of BCZTZICM, BSCF, and BCFZY at high temperatures. We tested their chemisorption capacity for water vapor within 45 minutes at 600℃. The figures show that BCZTZICM and BCFZY exhibit attenuated total reflectance infrared spectroscopy at 3500-3800 cm⁻¹. -1 The characteristic peaks of BCZTZICM and BCFZY are more obvious, while the characteristic peak intensity of BSCF is lower. After the water vapor is removed, the characteristic peaks of BCZTZICM and BCFZY disappear rapidly, indicating that water vapor has the ability to be rapidly adsorbed and desorbed on the electrode surface. However, the characteristic peak of BSCF still exists 45 minutes after the water vapor is removed, indicating that BSCF has poor water vapor desorption ability. During the electrolysis operation, water vapor adsorbed on oxygen vacancies is difficult to remove, which can easily lead to the inhibition of oxygen evolution reaction and reduce electrolysis performance.

[0105] 9. Characterization of hydration reaction activity

[0106] The test of the hydration reactivity of perovskite oxides containing variable valence elements includes the following specific steps:

[0107] (1) Weigh 0.5g of phase-forming powders BCZTZICM, BCFZY and BSCF respectively, compact them in a press, and granulate them using a 50-mesh sieve to obtain samples with uniform particle size.

[0108] (2) The sample was heated to 600°C in a tube furnace and treated with 20% steam for 2 hours.

[0109] (3) After processing, the sample should be quickly removed and cooled in the air.

[0110] (4) Prepare X-ray absorption spectrum transmission samples by mixing boron nitride with its variable valence element content.

[0111] (5) The near-edge structure of the sample to be tested is characterized by X-ray absorption spectrum, and its valence state change is tested.

[0112] Figure 9 The ae structure represents the near-edge X-ray absorption structure of variable-valence elements in BCZTZICM, BCFZY, and BSCF. Figure 9 After calibration with the standard sample of f, Figure 9g The changes in valence state of variable-valence elements in a single sample were summarized. Figure 9g BCZTZICM exhibits the largest valence state change at 0.056, indicating the formation of the most proton defects. This suggests that it possesses optimal hydration reactivity, resulting in superior proton conductivity and a significant advantage in proton-conducting solid oxide electrolytic cells.

[0113] 10. Characterization of Electrolytic Cell Electrolysis Performance

[0114] Electrolytic current density was tested using the electrolytic cell prepared in Example 3. Figure 10a shows the electrolytic current density (IV) test of a single cell (Ni-BZCYYb|BZCYYb|BCZTZICM) prepared with Ni-BZCYYb as the anode support, conducted in the temperature range of 500-650℃. The test results show that the electrolytic current density of BCZTZICM reaches 0.6, 0.9, 1.4, and 1.8 A cm⁻¹ at 500, 550, 600, and 650℃, respectively. -2 The BSCF and BCFZY electrodes shown in Figure 10 (bc) achieved 0.5, 0.7, 1.0, and 1.3 Acm at the corresponding temperatures, respectively. -2 .

[0115] 11. Characterization of Electrolytic Cell Stability

[0116] Figure 11 This is a stability graph of a single cell (Ni-BZCYYb|BZCYYb|BCZTZICM) fabricated using BCZTZICM as the air electrode and Ni-BZCYYb as the hydrogen electrode support, tested at 550℃. The graph shows the stability of the electrolyzer under an applied 500 mA / cm² pressure. -2 Under the electrolytic current, after 160 hours, there was no obvious voltage increase trend, which shows that the BCZTZICM material maintains excellent stability, providing a guarantee for commercialization.

[0117] 12. Thermogravimetric analysis (TGA) characterization

[0118] Figure 12 The TG curves for BCZTZICM, BSCF, and BCFZY are shown. The mass changes of the BCZTZICM, BSCF, and BCFZY samples in dry air from room temperature to 1000℃ are observed. BCZTZICM shows the least weight loss, while BSCF shows the most, indicating the greatest oxygen desorption. According to the principle of electroneutrality, the greater the change in ionic valence state and the greater the change in ionic radius in the structure of their respective materials, the better.

[0119] 13. Characterization of Coefficient of Thermal Expansion (TEC)

[0120] Figure 13 The coefficients of thermal expansion of BCZTZICM, BSCF, and BCFZY are used as a reference. The coefficient of thermal expansion of the electrolyte material BZCYYb was tested and found to be 11.98 × 10⁻⁶. -6 K -1 The coefficient of thermal expansion of BCZTZICM is 17.67 × 10⁻⁶. -6 K -1 The coefficients of thermal expansion of BSCF and BCFZY are 22.56 × 10⁻⁶. -6 K -1 and 26.08×10 -6 K -1 BCZTZICM exhibits the smallest coefficient of thermal expansion, indicating a higher degree of thermo-mechanical matching with the electrolyte.

[0121] 14. Characterization of X-ray near-edge structure (XANES)

[0122] Figure 14 The K-edge XANES spectra of BCZTZICM, BSCF, and BCFZY at room temperature and 600℃ are shown. Figure 14 The a-K edge XANES spectrum of BCZTZICM shows that the absorption edge of Co element from room temperature to high temperature shows a trend of changing to lower energy levels. This indicates that Co ions undergo thermal reduction, which leads to an increase in the number of coordination electrons near the ion and the energy required to excite electrons moves to lower energy levels. Figure 14bc is the XANES spectrum of the Co-K and Fe-K edges of BCFZY. Figure 14 The XANES spectra of the Co-K and Fe-K sides of BSCF, as shown by de, exhibit the same pattern described above. Figure 14 f represents the change in ionic valence state of BCZTZICM, BCFZY, and BSCF for comparison. By comparing the valence state changes from room temperature to high temperature, it can be concluded that BCZTZICM has the smallest change in the valence state of Co ions, at 0.0752, while BCFZY has a change of 0.117 and BSCF has a change of 0.247. This indicates that BCZTZICM has the least expansion of Co ions, resulting in the least thermal expansion of the material.

[0123] 15. X-ray photoelectron spectroscopy (XPS) characterization

[0124] Figure 15 XPS spectra of O1s in BCZTZICM, BSCF, and BCFZY are shown. The O1s binding energy of BCZTZICM is 531.7 eV, while that of BSCF is 531.2 eV and that of BCFZY is 531.3 eV. This indicates that multi-element doping at the B site of BCZTZICM enhances the metal-oxygen bond and suppresses the desorption of lattice oxygen, thereby achieving a lower coefficient of thermal expansion.

[0125] 16. Electrochemical impedance spectroscopy

[0126] Figure 16 The Arrhenius plots of ASR obtained on a BZCYYb symmetric cell for BCZTZICM, BSCF, and BCFZY under humidified air conditions in the range of 500-700℃ are shown. Under a humidified air atmosphere of 5% H2O, the polarization impedance Rp of BCZTZICM in the range of 500-700℃ are 0.998, 0.354, 0.163, 0.078, and 0.044 Ωcm, respectively. 2 This is lower than the typical proton-conducting cathode BCFZY at 500-700℃, which have Ωcm values ​​of 1.33, 0.662, 0.337, 0.195, and 0.097. 2 And the 2.54, 0.881, 0.311, 0.193, and 0.080 Ωcm values ​​for conductors containing a mixture of electrons and oxygen ions. 2 This demonstrates that BCZTZICM exhibits optimal ORR reactivity in proton-conducting symmetric cells.

[0127] 17. Fuel Cell Performance Testing

[0128] Preparation of Single Cells: Ni-BZCYYb anode-supported thin-film electrolyte single cells were prepared by dry pressing and high-temperature calcination co-pressing. First, 0.35g of anode powder was pressed into a disc under 2MPa pressure. Then, 0.015g of BZCYYb electrolyte powder was uniformly distributed on the anode surface and co-pressed under 2MPa pressure. The resulting bilayer pellets were then calcined in air at 1450℃ for 10 hours. Finally, cathode paste was applied to the center of the BZCYYb surface, with an effective area of ​​0.45cm². 2 Then, the three-layer battery was calcined at 1000℃ for 2 hours to obtain a single cell.

[0129] Assembly of a single cell: Apply silver paste to the electrodes on both sides of the prepared single cell, connect silver wires, and seal it on a ceramic tube with a diameter of 12 mm using silver paste.

[0130] Single-cell testing: Under a hydrogen atmosphere and open-circuit voltage, a current step of 10mA was applied to the single cell, and the IV value of the cell was acquired using a Keithley 2420 digital source meter.

[0131] Figure 17 These are the IV and IP curves of a Ni-BZCYYb|BZCYYb|BCZTZICM single cell in fuel cell mode within a temperature range of 650-500℃; in fuel cell mode, 60 mL of gas is introduced into the anode at a minimum temperature. -1 Hydrogen gas was introduced into the air electrode at a rate of 80 mL / min. -1 Dry air. The peak power densities of the BCZTZICM electrode at 650, 600, 550, and 500 °C were 1.3, 0.88, 0.68, and 0.49 W / cm², respectively. -2 The peak power of the BCFZY and BSCF electrodes at 650℃ was only 0.92 and 0.83 W cm⁻¹, respectively. -2 .

[0132] 18. Single-cell durability test

[0133] Figure 18 At 550℃, the BCZTZICM electrode at 300mA cm -2 Durability testing at constant current density was conducted; the stability of the BCZTZICM single cell under operating conditions was observed. The voltage of the single cell remained stable overall, and remained stable at 0.3 Acm for 200 hours. -2 It exhibits excellent durability under polarization conditions.

[0134] 19. XRD pattern of a single-element doped sample

[0135] Figure 19The XRD phase structures of the single-element doped samples and the six-element doped BCZTZICM were compared. None of the six single-element doped samples showed a cubic phase structure with space group Pm-3m, and impurity phases were present.

[0136] 20. XRD patterns of binary and quaternary doped samples

[0137] Figure 20 The XRD phase structures of binary and quaternary doped samples were compared with those of hexa-doped BCZTZICM. The phase structures of some binary and quaternary doped samples did not show a cubic phase structure with space group Pm-3m, and some samples had a hexagonal second phase with space group P63mmc.

Claims

1. A proton conductor solid oxide material, characterized in that, Its general formula is ABO 3-δ The perovskite oxide material has the molecular formula: BaCo 0.8 (Zr 1 / 6 Ti 1 / 6 Zn 1 / 6 In 1 / 6 Cu 1 / 6 Mo 1 / 6 ) 0.2 O 3-δ It has a cubic perovskite structure with space group Pm-3m, where δ represents the oxygen vacancy content.

2. The method for preparing the proton conductor solid oxide material according to claim 1, characterized in that, It is prepared by the sol-gel method according to stoichiometric ratio.

3. The preparation method according to claim 2, characterized in that, The sol-gel method includes the following steps: first, tetrabutyl titanate and ammonium molybdate are heated with deionized water and citric acid monohydrate until clear and transparent, and then they are prepared by sol-gel method with barium nitrate, cobalt nitrate, zirconium nitrate, zinc nitrate, indium nitrate and copper nitrate according to the stoichiometric ratio in the molecular formula.

4. The preparation method according to claim 3, characterized in that, The sol-gel method includes the following steps: First, tetrabutyl titanate and ammonium molybdate are dissolved in deionized water and citric acid monohydrate by heating until clear and transparent. Then, barium nitrate, cobalt nitrate, zinc nitrate, zirconium nitrate, copper nitrate, and indium nitrate are added, dissolved, and heated and stirred. Ethylenediaminetetraacetic acid is added, and then ammonia water is added dropwise until the pH of the solution is between 7 and 8. Under heating and stirring conditions, the water is evaporated to obtain a gel-like substance. The gel-like substance is placed in an oven to dry, obtaining an air electrode material precursor. The precursor is then placed in a muffle furnace for calcination to obtain a proton conductor solid oxide material.

5. The preparation method according to claim 4, characterized in that, The total molar ratio of ethylenediaminetetraacetic acid and citric acid to Ba, Co, Zr, Ti, Zn, In, Cu, and Mo is 2:0.5-1.5:0.5-1.

5.

6. The preparation method according to claim 4, characterized in that, The drying process is carried out at 160-200℃ for 5-8 hours; the calcination parameters are 1000℃ for 1-10 hours.

7. The use of the proton conductor solid oxide material according to claim 1 as a proton conductor in water electrolysis or in a fuel cell.

8. The use according to claim 7, characterized in that, The electrolyte used is BaZr. 0.1 Ce 0.7 Y 0.1 Yb 0.1 O3; the anode material is NiO and BaZr. 0.1 Ce 0.7 Y 0.1 Yb 0.1 A composite anode composed of O3.

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