A solid oxide fuel cell barrier material and method of making the same

Abstract

The application discloses a solid oxide fuel cell barrier material and a preparation method thereof, and the preparation method comprises the following steps: 1) preparing a YSZ / GDC base layer; 2) preparing an alloy slurry; and 3) preparing an HEO layer. The high-entropy oxide design is utilized to form a high-entropy structure with severe lattice distortion and a multi-element chemical environment; the ratio of rare earth elements to transition metals is optimized to accurately control the thermal expansion coefficient of the barrier layer; and the thickness of the YSZ / GDC base layer / HEO layer is adjusted to obtain a barrier layer material capable of significantly inhibiting element diffusion and having high ionic conductivity. The application effectively solves the problems of high interface resistance and poor long-term stability of a traditional barrier layer, provides a reliable material basis for efficient and stable operation of the SOFC, and has important industrial application value.

Description

Technical Field

[0001] This invention relates to the field of solid oxide fuel cell technology, and in particular to a solid oxide fuel cell barrier layer material and its preparation method. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are power generation devices that directly convert chemical energy into electrical energy. A typical solid oxide fuel cell consists of a three-layer structure: cathode, electrolyte, and anode.

[0003] However, the cathode materials currently used have poor chemical compatibility with the most widely used and mature zirconia-based electrolytes, such as YSZ (yttrium-doped zirconia) and ScSZ (scandium-doped zirconia). During the sintering and operation of the cathode, they are prone to chemical reactions with the zirconia-based electrolyte, generating high-resistivity impurities at the cathode-electrolyte interface, which causes a sharp decline in battery performance. Furthermore, the cathode and the zirconia-based electrolyte have significantly different thermal expansion properties, and the cathode may detach from the electrolyte under repeated temperature changes.

[0004] Therefore, an electrode barrier layer is usually added between the cathode and the electrolyte to isolate and stabilize the electrolyte and electrode. The SOFC reaction begins at the cathode, where oxygen molecules (O2) are converted into ionic forms (O3). 2- ), O 2- The electrolyte is transported to the anode to react with renewable fuel. Its operating temperature is usually between 400-1000℃, which is the highest operating temperature of all fuel cells.

[0005] Traditional barrier layer materials, such as cerium oxide-based materials like GDC (gadolinium-doped cerium oxide), have high oxygen ion conductivity and are compatible with the expansion coefficient of zirconium oxide-based electrolytes. However, they have poor sintering activity and cannot be sintered densely under current processes. Furthermore, they can react chemically with zirconium oxide at high temperatures to form a high-resistivity cerium-zirconium oxide solid solution, which greatly reduces the reusability of the battery.

[0006] Therefore, the barrier layer material of SOFC must simultaneously possess the properties of blocking Zr diffusion between the electrolyte and the electrode, matching the coefficient of thermal expansion (CTE) with the electrolyte, and efficiently conducting O. 2- Furthermore, it possesses the ability to operate stably at high temperatures. Currently, a dense, non-impeding O... 2- Materials that conduct electricity and possess high-temperature stability for barrier layers are still under investigation. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by proposing a solid oxide fuel cell barrier layer material and its preparation method.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] This invention first proposes a solid oxide fuel cell barrier layer material, comprising the following steps:

[0010] Preparation of S1 and YSZ / GDC matrix layers

[0011] Preparation of S1.1, YSZ matrix green body:

[0012] The YSZ slurry is cast onto an electrolyte sheet to form a thin film, and then dried at 60-80℃ for 12-24 hours to ensure complete drying, thus obtaining a YSZ matrix layer green body.

[0013] S1.2 Preparation of GDC matrix green body:

[0014] GDC slurry is cast into a thin film on a YSZ substrate green body and dried at 60-80℃ for 12-24 hours to ensure complete drying, thus obtaining a GDC substrate green body.

[0015] S1.3, Lamination and Co-sintering:

[0016] The GDC matrix green blank, YSZ matrix green blank, electrolyte sheet, and anode sheet are stacked, vacuum sealed, and isostatically pressed at 50 MPa for 20 min at 70°C to obtain the composite green blank.

[0017] After sintering the composite green body, a single-cell blank containing a YSZ / GDC matrix layer is formed.

[0018] S2, Preparation of alloy slurry

[0019] S2.1 Preprocessing:

[0020] After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, metal powders with a particle size of less than 1 μm were obtained.

[0021] S2.2 Preparation of alloy slurry:

[0022] Metals La, Ce, Nd, Gd, Co, Cu, and Al were mixed in a specific molar ratio. Polyvinyl butyral and dibutyl phthalate were added, and the mixture was ball-milled for 24 hours under the same conditions. After filtration, the mixture was vacuum degassed for 30 minutes to obtain a high-entropy alloy (La). 1 / 5Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy slurry, wherein 40≤y≤60, 11.5≤z≤17.5, x+y+z=100;

[0023] Preparation of S3 and HEO layers

[0024] The high-entropy alloy (La) was applied using a drop-coating method. 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z The alloy slurry was dripped onto the surface of the YSZ / GDC substrate layer of the single cell blank. After being evenly coated, it was dried at 60°C for 2 hours to obtain the single cell blank.

[0025] The single-cell blank was sintered a second time using a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The program was set as follows:

[0026] ① Heating from room temperature to 400℃ at a heating rate of 1-2℃ / min, followed by vacuum sintering;

[0027] ② Increase the temperature to 800℃ at a heating rate of 3℃ / min, hold for 1 hour, and then vacuum sinter;

[0028] This temperature reaches the eutectic point of Co / Cu / Al, and Al begins to penetrate into GDC, filling the gaps between molecules in GDC and making the GDC layer more compact.

[0029] ③ The temperature was further increased to 1200℃ at a heating rate of 2℃ / min, held for 4 hours, and then vacuum sintered.

[0030] At this temperature, high-entropy alloys begin to form, and the metals begin to dissolve into each other. Due to the different atomic radii, larger diameter atoms push away the surrounding atoms, while smaller diameter atoms have excess space around them, leading to severe lattice distortion. This variability in atomic position gives high-entropy alloys a larger configurational entropy and also places them in a state of continuous lattice distortion.

[0031] ④ The sample is cooled in the furnace under a mixed atmosphere of 7% oxygen and 93% nitrogen, and the cooling rate is controlled to be no more than 5℃ / min.

[0032] Introducing oxygen during the formation of the thin film promotes the generation of metal oxides. According to the literature "Study on the diffusion barrier effect of high-entropy alloys and their oxide films on Cu-Si", the study on the transformation of high-entropy alloys into high-entropy oxides shows that when the oxygen concentration is 7%, the elements on the surface of the prepared film are evenly distributed, without large-area defects or agglomerations, and the film quality is good.

[0033] A single cell containing a high-entropy alloy oxide (HEO) layer was obtained by secondary sintering.

[0034] Preferably, the electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO / YSZ composite anode.

[0035] Preferably, the preparation process of the YSZ slurry is as follows: after pretreatment of YSZ powder, anhydrous ethanol and dispersant anhydrous triethanolamine are added and ball-milled for 24 hours to obtain YSZ composite powder suspension;

[0036] Polyvinyl butyral and dibutyl phthalate were added to the YSZ composite powder suspension, and the mixture was ball-milled for 24 hours. After filtration, the mixture was degassed under vacuum for 30 minutes to obtain the YSZ slurry.

[0037] The mass ratio of YSZ powder, starch powder, solvent anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:2-4:160-240:8-12:9-11:2-5;

[0038] Where YSZ refers to Y 0.16 Zr 0.92 O2, i.e., yttrium-doped zirconium oxide.

[0039] Preferably, the preparation process of the GDC slurry is as follows: CeO2 powder, Gd2O3 powder, anhydrous ethanol and ammonium polyacrylate are mixed and ball-milled for 24 hours, dried at 60-80℃ for 12-24 hours, and passed through a 200-mesh sieve to obtain GDC composite powder;

[0040] After calcining the GDC composite powder, anhydrous ethanol, polyvinyl butyral and dibutyl phthalate were added, and the mixture was ball-milled for 24 hours. After filtration, the mixture was vacuum degassed for 30 minutes to obtain the GDC slurry.

[0041] The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:350-450:1-3:15-25:5-7.

[0042] GDC refers to Ce 0.90 Gd 0.10 O 1.95 That is, gadolinium-doped cerium oxide.

[0043] Preferably, the specific steps for sintering the composite green body are as follows:

[0044] The composite green body was laid flat on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The sintering atmosphere was air, and the program was set as follows:

[0045] ① Heat from room temperature to 600℃ at a heating rate of 2℃ / min and hold for 4 hours;

[0046] ② Increase the temperature from 600℃ to 1000℃ at a rate of 5℃ / min and hold for 1 hour;

[0047] ③ Increase the temperature from 1000℃ to 1400℃ at a rate of 2℃ / min and hold for 4 hours;

[0048] ④ During cooling, the cooling rate should be ≤5℃ / min, and the product should be removed when the temperature drops below 200℃;

[0049] The sintering program is set to match the requirements of organic matter decomposition (600℃), preliminary grain growth (1000℃), and densification (1400℃) to avoid cracking of the green blank.

[0050] In the matrix layer, the thickness ratio of the YSZ matrix green and the GDC matrix green is 1:1; the thickness of the YSZ / GDC matrix layer obtained by S1 is 8-16 μm.

[0051] Preferably, the specific process of preprocessing is as follows:

[0052] After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, they are placed into the tungsten carbide cemented carbide ball mill jar of QM-3SP4 planetary ball mill. Grinding balls are weighed at a ball-to-material ratio of 15:1 and placed into the ball mill jar. Anhydrous ethanol and anhydrous triethanolamine are added.

[0053] The atmosphere was kept as high-purity Ar through three vacuum-gas cycles, with a final pressure of 0.5 MPa. The ball mill was run at 350 rpm for 24 hours to obtain a suspension. The suspension was placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes. The suspension was then cooled in a water bath to maintain a temperature below 40°C. After ultrasonication, the suspension was centrifuged at 3000 rpm for 10 minutes. The supernatant was then placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain metal powder with a particle size of less than 1 μm.

[0054] Preferably, the mass ratio of high entropy alloy, anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:160-240:15-25:8-12:2-4.

[0055] Preferably, the thickness of the obtained high-entropy alloy oxide (HEO) layer is 2-4 μm.

[0056] Compared with the prior art, the beneficial effects of the present invention are:

[0057] 1. Higher density and thermal stability

[0058] In addition to adding a dense HEO layer to the traditional GDC layer, this invention employs a gradient sintering method during sintering. This allows Al, with its smaller atomic radius, to penetrate between CeO2 molecules at 800°C. During vacuum sintering at 1200°C, a dense high-entropy alloy HEA layer is formed on the surface of the GDC layer. During annealing, the atmosphere is switched to a mixture of 7% oxygen and 93% nitrogen. Oxygen atoms can fill the spaces between grains to enhance solid solution strengthening, improve the film-substrate adhesion, and thus enhance the density of the film.

[0059] For the GDC layer, the introduction of oxygen oxidizes Al to Al2O3, filling the sintering defects of GDC. For the original HEA layer, the crystal structure of the oxidized HEO is still mainly amorphous. A small amount of oxygen can promote the precipitation of a small amount of BCC structure in the film, increase the configuration entropy, and further improve the thermal stability of the barrier layer.

[0060] When operating as a barrier layer, the phase transition temperature of this invention remains above 1200°C, which is significantly higher than the normal operating temperature of SOFC.

[0061] 2. Adjustable coefficient of thermal expansion

[0062] The mixing of different CTEs in the material generates a local strain field, which in turn counteracts the anisotropy of thermal expansion. By changing the proportions of each material in the barrier layer, the CTE of the barrier layer can be artificially controlled. Therefore, the CTE of this invention can be precisely controlled through composition design to match that of the electrolyte (YSZ has a CTE of 10.5 × 10⁻⁶). -6 / K, This invention is based on high-entropy alloy (La) 1 / 5 Nd 1 / 5 Gd 1 / 5Co 1 / 5 Cu 1 / 5 ) 35.5 Ce 50 Al 14.5 The CTE of the obtained HEO layer is 10×10 -6 / K) Highly matched, avoiding barrier layer detachment caused by CTE imbalance.

[0063] 3. High oxygen negative ion conduction efficiency

[0064] This barrier layer possesses a high-entropy structure, which facilitates the migration of oxygen anions—its crystal structure lacks a clearly ordered arrangement, resulting in more diverse diffusion paths for oxygen ions within the material. This allows oxygen ions to migrate through different channels and locations, reducing mutual obstruction between oxygen ions and increasing their migration rate.

[0065] Furthermore, due to the presence of numerous different types of atomic or ionic substitution sites, the high-entropy system exhibits a more microscopic state and a higher Sconf (configurational entropy). Therefore, this barrier layer can promote the disordered movement of oxygen ions, reduce the activation energy, and simultaneously create an efficient diffusion barrier, lowering the oxygen ion migration activation energy to 0.82 eV, thus enabling the material to possess high oxygen negative ion conduction efficiency.

[0066] 4. Vacancy regulation blocks Zr diffusion.

[0067] Zr diffusion essentially involves the formation of a new phase on the barrier layer or cathode material. The formation of a new phase requires the coordinated diffusion of many atoms to complete the redistribution of elements. In the HEO layer of this barrier layer, the size differences of various atoms cause severe lattice distortion in the material, which leads to a significant difference between the element diffusion channels and diffusion activation energies of this invention and those of traditional materials.

[0068] In traditional barrier layers, Zr can generate stable high-resistivity impurities at the cathode-electrolyte interface. This stability makes SOFCs prone to generating impurities when operating at high temperatures.

[0069] In this invention, the reactivity of each element with Zr is low, and because the atoms surrounding each lattice point in the HEO layer are different, the atoms adjacent to Zr after migrating to a vacancy are also different. The bonding of atoms at different lattice points varies, and the binding energies at different lattice points also differ. This results in Zr being "trapped" when migrating to a low-energy lattice point, reducing the probability of it subsequently migrating out of that location. The large fluctuations in lattice potential energy between lattice points cause relatively slow diffusion of elements in the barrier layer; a large number of low-lattice potential lattice points restrict and hinder atomic diffusion, which is the so-called hysteresis diffusion effect.

[0070] This effect macroscopically reduces the diffusion coefficient and enhances the barrier layer's ability to isolate the electrolyte from the battery cathode.

[0071] In summary, this invention, by adding a layer of HEO with precisely tunable CTE to existing GDC barrier layer materials, produces a barrier layer with high density and high thermal stability, CTE adapted to the electrolyte layer, and high O2 content. 2- The high conductivity and ability to block the diffusion of Zr elements provide a reliable material basis for the efficient and stable operation of SOFCs, which has important industrial application value. Detailed Implementation

[0072] Figure 1 This is a process flow diagram for producing the solid oxide fuel cell barrier layer material according to the present invention.

[0073] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0074] Example 1:

[0075] A method for preparing a solid oxide fuel cell barrier layer material includes the following steps:

[0076] Preparation of S1 and YSZ / GDC matrix layers

[0077] Preparation of S1.1, YSZ matrix green body:

[0078] After pretreatment, 100g of YSZ powder was mixed with anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant and ball-milled for 24h to obtain a YSZ composite powder suspension.

[0079] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and then degas under vacuum for 30 minutes to obtain YSZ slurry.

[0080] YSZ slurry was cast onto an electrolyte sheet to form a thin film, and dried in an oven at 60°C for 24 hours to ensure complete drying, thus obtaining a YSZ substrate green body.

[0081] S1.2 Preparation of GDC matrix green body:

[0082] 89.5g of CeO2 powder and 10.5g of Gd2O3 powder, anhydrous ethanol solvent and ammonium polyacrylate dispersant were mixed and ball-milled for 24h, dried in an oven at 60℃ for 24h, and passed through a 200-mesh sieve to obtain GDC composite powder.

[0083] After calcining the GDC composite powder, add anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain GDC slurry.

[0084] GDC slurry was cast into a thin film on a YSZ substrate green body and dried in an oven at 60°C for 24 hours to ensure complete drying, thus obtaining a GDC substrate green body.

[0085] S1.3, Lamination and Co-sintering:

[0086] The GDC matrix green blank, YSZ matrix green blank, electrolyte sheet, and anode sheet are stacked, vacuum sealed, and isostatically pressed at 50 MPa for 20 min at 70°C to obtain the composite green blank.

[0087] After sintering the composite green body, a single-cell blank containing a YSZ / GDC matrix layer is formed.

[0088] S2, high-entropy alloy (La) 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Preparation of alloy paste

[0089] S2.1 Preprocessing:

[0090] After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, they are placed into the tungsten carbide cemented carbide ball mill jar of QM-3SP4 planetary ball mill. Grinding balls are weighed at a ball-to-material ratio of 15:1 and placed into the ball mill jar. Anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant are added.

[0091] The atmosphere was kept as high-purity Ar by three vacuum-gas cycles, with a final pressure of 0.5 MPa. The ball mill was run at 350 rpm for 24 hours to obtain a suspension. The suspension was placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes. The suspension was then cooled in a water bath to keep the temperature below 40°C. After ultrasonication, the suspension was centrifuged at 3000 rpm for 10 minutes. The supernatant was then placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain metal powder with a particle size of less than 1 μm.

[0092] S2.2 Preparation of alloy slurry:

[0093] Metal powders of La, Ce, Nd, Gd, Co, Cu, and Al, including 4.7 g of Al, 56.0 g of Ce, 7.1 g of La, 11.8 g of Nd, 12.3 g of Gd, 5.0 g of Co, and 5.4 g of Cu, were mixed. Anhydrous ethanol was added as a solvent, polyvinyl butyral as a binder, and dibutyl phthalate as a plasticizer. The mixture was ball-milled for 24 hours under the same conditions. After filtration, vacuum degassing was performed for 30 minutes to obtain a high-entropy alloy (La). 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy paste;

[0094] Preparation of S3 and HEO layers

[0095] The high-entropy alloy (La) was applied using a drop-coating method. 1 / 5 Nd1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy slurry is dripped onto the surface of the substrate layer, and after being evenly coated, it is dried at 60°C for 2 hours to obtain a single cell blank;

[0096] The single-cell blank was sintered a second time using a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The program was set as follows:

[0097] ① Heating from room temperature to 400℃ at a heating rate of 2℃ / min, followed by vacuum sintering;

[0098] ② Increase the temperature to 800℃ at a heating rate of 3℃ / min, hold for 1 hour, and then vacuum sinter;

[0099] ③ The temperature was further increased to 1200℃ at a heating rate of 2℃ / min, held for 4 hours, and then vacuum sintered.

[0100] ④ The sample was cooled in the furnace under a mixed atmosphere of 7% oxygen and 93% nitrogen, with the cooling rate controlled at 5℃ / min.

[0101] A single cell containing a high-entropy alloy oxide (HEO) layer was obtained by secondary sintering.

[0102] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0103] The mass ratio of YSZ powder, starch powder, solvent anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:2:120:80:11:2.

[0104] The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:350:3:15:7.

[0105] The specific steps for sintering the composite green body are as follows:

[0106] The composite green body was laid flat on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The sintering atmosphere was air, and the program was set as follows:

[0107] ① Heat from room temperature to 600℃ at a heating rate of 2℃ / min and hold for 4 hours;

[0108] ② Increase the temperature from 600℃ to 1000℃ at a rate of 5℃ / min and hold for 1 hour;

[0109] ③ Increase the temperature from 1000℃ to 1400℃ at a rate of 2℃ / min and hold for 4 hours;

[0110] ④ During cooling, the cooling rate is 5℃ / min, and the product is removed when the temperature drops below 200℃;

[0111] The thickness ratio of the YSZ matrix green blank to the GDC matrix green blank is 1:1.

[0112] The sintering program is set to match the requirements of organic matter decomposition (600℃), preliminary grain growth (1000℃), and densification (1400℃) to avoid cracking of the green blank.

[0113] The thickness of the prepared matrix layer is 8 μm.

[0114] Where y=40, z=17.5, x=42.5; the mass ratio of high entropy alloy, anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:160:25:8:4.

[0115] The thickness of the obtained metal oxide layer is 4 μm.

[0116] Example 2:

[0117] A method for preparing a solid oxide fuel cell barrier layer material includes the following steps:

[0118] Preparation of S1 and YSZ / GDC matrix layers

[0119] Preparation of S1.1, YSZ matrix green body:

[0120] After pretreatment of 150g of YSZ powder, anhydrous ethanol and anhydrous triethanolamine were added as solvents and ball-milled for 24h to obtain a YSZ composite powder suspension.

[0121] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and then degas under vacuum for 30 minutes to obtain YSZ slurry.

[0122] YSZ slurry was cast onto an electrolyte sheet to form a thin film, and dried at 60°C for 24 hours to ensure complete drying, thus obtaining a YSZ substrate green body.

[0123] S1.2 Preparation of GDC matrix green body:

[0124] 134.3g of CeO2 powder, 15.7g of Gd2O3 powder, anhydrous ethanol solvent, and ammonium polyacrylate dispersant were mixed and ball-milled for 24h, dried in an oven at 60℃ for 24h, and passed through a 200-mesh sieve to obtain GDC composite powder.

[0125] After calcining the GDC composite powder, add anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain GDC slurry.

[0126] GDC slurry was cast into a thin film on a YSZ substrate green body and dried in an oven at 60°C for 24 hours to ensure complete drying, thus obtaining a GDC substrate green body.

[0127] S1.3, Lamination and Co-sintering:

[0128] The GDC matrix green blank, YSZ matrix green blank, electrolyte sheet, and anode sheet are stacked, vacuum sealed, and isostatically pressed at 50 MPa for 20 min at 70°C to obtain the composite green blank.

[0129] After sintering the composite green body, a single-cell blank containing a YSZ / GDC matrix layer is formed.

[0130] S2, high-entropy alloy (La) 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Preparation of alloy paste

[0131] S2.1 Preprocessing:

[0132] After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, they are placed into the tungsten carbide cemented carbide ball mill jar of QM-3SP4 planetary ball mill. Grinding balls are weighed at a ball-to-material ratio of 15:1 and placed into the ball mill jar. Anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant are added.

[0133] The atmosphere was kept as high-purity Ar by three vacuum-gas cycles, with a final pressure of 0.5 MPa. The ball mill was run at 350 rpm for 24 hours to obtain a suspension. The suspension was placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes. The suspension was then cooled in a water bath to keep the temperature below 40°C. After ultrasonication, the suspension was centrifuged at 3000 rpm for 10 minutes. The supernatant was then placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain metal powder with a particle size of less than 1 μm.

[0134] S2.2 Preparation of alloy slurry:

[0135] Metal powders of La, Ce, Nd, Gd, Co, Cu, and Al, including 3.9 g of Al, 70.1 g of Ce, 9.9 g of La, 10.2 g of Nd, 11.2 g of Gd, 4.2 g of Co, and 4.5 g of Cu, were mixed. Anhydrous ethanol, polyvinyl butyral (a binder), and dibutyl phthalate (a plasticizer) were added. The mixture was ball-milled for 24 hours under the same conditions. After filtration, vacuum degassing was performed for 30 minutes to obtain a high-entropy alloy (La). 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy paste;

[0136] Preparation of S3 and HEO layers

[0137] The high-entropy alloy (La) was applied using a drop-coating method. 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy slurry is dripped onto the surface of the substrate layer, and after being evenly coated, it is dried at 60°C for 2 hours to obtain a single cell blank;

[0138] The single-cell blank was sintered a second time using a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The program was set as follows:

[0139] ① Heating from room temperature to 400℃ at a heating rate of 1-2℃ / min, followed by vacuum sintering;

[0140] ② Increase the temperature to 800℃ at a heating rate of 3℃ / min, hold for 1 hour, and then vacuum sinter;

[0141] ③ The temperature was further increased to 1200℃ at a heating rate of 2℃ / min, held for 4 hours, and then vacuum sintered.

[0142] ④ The sample was cooled in the furnace under a mixed atmosphere of 7% oxygen and 93% nitrogen, with the cooling rate controlled at 5℃ / min.

[0143] A single cell containing a high-entropy alloy oxide (HEO) layer was obtained by secondary sintering.

[0144] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0145] The mass ratio of YSZ powder, starch powder, anhydrous ethanol solvent, anhydrous triethanolamine dispersant, polyvinyl butyral binder, and dibutyl phthalate plasticizer is 100:3:100:10:10:3.5.

[0146] The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:400:2:20:6.

[0147] The specific steps for sintering the composite green body are as follows:

[0148] The composite green body was laid flat on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The sintering atmosphere was air, and the program was set as follows:

[0149] ① Heat from room temperature to 600℃ at a heating rate of 2℃ / min and hold for 4 hours;

[0150] ② Increase the temperature from 600℃ to 1000℃ at a rate of 5℃ / min and hold for 1 hour;

[0151] ③ Increase the temperature from 1000℃ to 1400℃ at a rate of 2℃ / min and hold for 4 hours;

[0152] ④ During cooling, the cooling rate is 5℃ / min, and the product is removed when the temperature drops below 200℃;

[0153] The thickness ratio of the YSZ matrix green blank to the GDC matrix green blank is 1:1.

[0154] The sintering program is set to match the requirements of organic matter decomposition (600℃), preliminary grain growth (1000℃), and densification (1400℃) to avoid cracking of the green blank.

[0155] The thickness of the prepared matrix layer is 12 μm.

[0156] Where y=50, z=14.5, x=35.5; the mass ratio of high entropy alloy, anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:200:20:10:3.

[0157] The thickness of the obtained metal oxide layer is 3 μm.

[0158] Example 3:

[0159] A method for preparing a solid oxide fuel cell barrier layer material includes the following steps:

[0160] Preparation of S1 and YSZ / GDC matrix layers

[0161] Preparation of S1.1, YSZ matrix green body:

[0162] After pretreatment of 200g of YSZ powder, anhydrous ethanol and anhydrous triethanolamine were added as solvents and ball-milled for 24h to obtain a YSZ composite powder suspension.

[0163] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and then degas under vacuum for 30 minutes to obtain YSZ slurry.

[0164] YSZ slurry was cast onto an electrolyte sheet to form a thin film, and dried in an oven at 60°C for 24 hours to ensure complete drying, thus obtaining a YSZ substrate green body.

[0165] S1.2 Preparation of GDC matrix green body:

[0166] 179.1g of CeO2 powder, 20.9g of Gd2O3 powder, anhydrous ethanol solvent, and ammonium polyacrylate dispersant were mixed and ball-milled for 24h, dried in an oven at 60℃ for 24h, and passed through a 200-mesh sieve to obtain GDC composite powder.

[0167] After calcining the GDC composite powder, add anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain GDC slurry.

[0168] GDC slurry was cast into a thin film on a YSZ substrate green body and dried in an oven at 60°C for 24 hours to ensure complete drying, thus obtaining a GDC substrate green body.

[0169] S1.3, Lamination and Co-sintering:

[0170] The GDC matrix green blank, YSZ matrix green blank, electrolyte sheet, and anode sheet are stacked, vacuum sealed, and isostatically pressed at 50 MPa for 20 min at 70°C to obtain the composite green blank.

[0171] After sintering the composite green body, a single-cell blank containing a YSZ / GDC matrix layer is formed.

[0172] S2, high-entropy alloy (La) 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Preparation of alloy paste

[0173] S2.1 Preprocessing:

[0174] After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, they are placed into the tungsten carbide cemented carbide ball mill jar of QM-3SP4 planetary ball mill. Grinding balls are weighed at a ball-to-material ratio of 15:1 and placed into the ball mill jar. Anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant are added.

[0175] The atmosphere was kept as high-purity Ar by three vacuum-gas cycles, with a final pressure of 0.5 MPa. The ball mill was run at 350 rpm for 24 hours to obtain a suspension. The suspension was placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes. The suspension was then cooled in a water bath to keep the temperature below 40°C. After ultrasonication, the suspension was centrifuged at 3000 rpm for 10 minutes. The supernatant was then placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain metal powder with a particle size of less than 1 μm.

[0176] S2.2 Preparation of alloy slurry:

[0177] Metal powders of La, Ce, Nd, Gd, Co, Cu, and Al, including 3.1 g of Al, 84.1 g of Ce, 7.9 g of La, 8.2 g of Nd, 9.0 g of Gd, 3.4 g of Co, and 3.6 g of Cu, were mixed. Anhydrous ethanol, polyvinyl butyral (a binder), and dibutyl phthalate (a plasticizer) were added. The mixture was ball-milled for 24 hours under the same conditions. After filtration, vacuum degassing was performed for 30 minutes to obtain a high-entropy alloy (La). 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy paste;

[0178] S3. Fabrication of a single cell containing a substrate layer / HEO (high entropy oxide) barrier layer.

[0179] The high-entropy alloy (La) was applied using a drop-coating method. 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy slurry is dripped onto the surface of the substrate layer, and after being evenly coated, it is dried at 60°C for 2 hours to obtain a single cell blank;

[0180] The single-cell blank was sintered a second time using a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The program was set as follows:

[0181] ① Heating from room temperature to 400℃ at a heating rate of 1-2℃ / min, followed by vacuum sintering;

[0182] ② Increase the temperature to 800℃ at a heating rate of 3℃ / min, hold for 1 hour, and then vacuum sinter;

[0183] ③ The temperature was further increased to 1200℃ at a heating rate of 2℃ / min, held for 4 hours, and then vacuum sintered.

[0184] ④ The sample was cooled in the furnace under a mixed atmosphere of 7% oxygen and 93% nitrogen, with the cooling rate controlled at 5℃ / min.

[0185] A single cell containing a high-entropy alloy oxide (HEO) layer was obtained by secondary sintering.

[0186] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0187] The mass ratio of YSZ powder, starch powder, anhydrous ethanol solvent, anhydrous triethanolamine dispersant, polyvinyl butyral binder, and dibutyl phthalate plasticizer is 100:4:80:12:9:5.

[0188] The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:450:1:25:5.

[0189] The specific steps for sintering the composite green body are as follows:

[0190] The composite green body was laid flat on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The sintering atmosphere was air, and the program was set as follows:

[0191] ① Heat from room temperature to 600℃ at a heating rate of 2℃ / min and hold for 4 hours;

[0192] ② Increase the temperature from 600℃ to 1000℃ at a rate of 5℃ / min and hold for 1 hour;

[0193] ③ Increase the temperature from 1000℃ to 1400℃ at a rate of 2℃ / min and hold for 4 hours;

[0194] ④ During cooling, the cooling rate is 5℃ / min, and the product is removed when the temperature drops below 200℃;

[0195] The thickness ratio of the YSZ matrix green blank to the GDC matrix green blank is 1:1.

[0196] The sintering program is set to match the requirements of organic matter decomposition (600℃), preliminary grain growth (1000℃), and densification (1400℃) to avoid cracking of the green blank.

[0197] The thickness of the prepared matrix layer is 16 μm.

[0198] y=60, z=11.5, x=28.5; the mass ratio of high entropy alloy, anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:240:15:12:2.

[0199] The thickness of the obtained metal oxide layer is 2 μm.

[0200] Based on this, the following design was also created:

[0201] Comparative Example 1: Same formulation and experimental method as Example 2, but without the addition of Al;

[0202] Comparative Example 2: The formulation and experimental method were the same as in Example 2, but an excess of Al was added;

[0203] Comparative Example 3: Same formulation and experimental method as Example 2, but without the addition of Ce;

[0204] Comparative Example 4: Same formulation and experimental method as Example 2, but with the addition of excess Ce;

[0205] Comparative Example 5: Same formulation and experimental method as Example 2, but without the addition of La, Gd, Nd, Co and Cu;

[0206] Comparative Example 6: The formulation and experimental methods were the same as in Example 2, but excess La, Gd, Nd, Co, and Cu were added;

[0207] Comparative Example 7: The formulation and experimental methods were the same as in Example 2, but YSZ powder, CeO2 powder, and Gd2O3 powder were not added.

[0208] Comparative Example 8: The formulation and experimental method were the same as in Example 2, but excess YSZ powder, CeO2 powder, and Gd2O3 powder were added;

[0209] Comparative Example 9: The elemental composition and experimental methods were the same as in Example 2, but only a 1 μm alloy layer was prepared;

[0210] Comparative Example 10: The formulation and experimental methods were the same as in Example 2, but a 10 μm alloy layer was prepared;

[0211] The specific formulation and test methods are shown in Table 1:

[0212] Table 1. Formulation of barrier layer for solid oxide fuel cells

[0213]

[0214] Each embodiment and comparative example underwent specific performance testing, and the testing methods and corresponding results are shown below:

[0215] 1. Ionic conductivity (800℃, S / cm)

[0216] Alternating current impedance spectroscopy (EIS): Using a two-electrode method, platinum (Pt) is used as the electrode material to form a cell with a single cell. The impedance spectrum at different frequencies (0.1Hz-1MHz) is measured at 800℃. The bulk resistance (Rb) and grain boundary resistance (Rgb) are obtained by fitting the Nyquist plot.

[0217]

[0218] Where L is the thickness and A is the electrode area.

[0219] 2. Electronic conductivity (800℃, S / cm)

[0220] DC four-probe method: Eliminates the influence of contact resistance, directly measures electronic conductivity, uses platinum (Pt) as electrode material, and forms a cell with a single cell to ensure the accuracy of electron transport.

[0221] 3. Activation energy (eV)

[0222] Temperature-dependent impedance spectroscopy: Conductivity was measured at different temperatures (600-800℃), and the activation energy Ea was fitted using the Arrhenius formula.

[0223]

[0224] Where σ0 represents the electrical conductivity of the material at infinite temperature (usually 0 K, absolute zero), and Ea is the activation energy, which represents the energy barrier that charge carriers (such as electrons or ions) in the material need to overcome, and the unit is electron volt (eV).

[0225] k is the Boltzmann constant, approximately 1.38 × 10⁻⁶. −23 J / K.

[0226] T is absolute temperature, and its unit is Kelvin (K).

[0227] 4. Open circuit voltage (OCV, 700℃, V)

[0228] Fuel cell testing system: combining a single cell with an LSM (La) 0.8 Sr 0.2A solid oxide fuel cell composed of MnO3 (lanthanum, strontium, and manganese oxide) was used. H2 (anode) and air (cathode) were introduced at 700°C. The OCV under no-load conditions was directly measured using a high-impedance voltmeter to verify the airtightness of the barrier layer (the ideal value is close to the Nernst voltage).

[0229] 5. Maximum power density (750℃, W / cm³) 2 )

[0230] IV / PV curve testing: A single cell was compared with an LSM (La) 0.8 Sr 0.2 A solid oxide fuel cell composed of MnO3 (lanthanum, strontium, and manganese oxide) was used. H2 (anode) and air (cathode) were introduced at 700°C. At 750°C, the current-voltage curve was recorded using an electrochemical workstation, and the power density P was calculated and the maximum value was taken.

[0231]

[0232] Where A is the electrode area.

[0233] 6. Bond strength (MPa)

[0234] Tensile / shear test: After bonding the barrier layer to the electrolyte or electrode layer, a shear test is performed using a universal testing machine, and the breaking strength is recorded.

[0235] 7. Hardness (GPa)

[0236] Nanoindentation: Hardness H is calculated using a Berkovich indenter via load-displacement curves.

[0237]

[0238] Where Ac is the contact area.

[0239] 8. Fracture toughness (MPa·m) 1 / 2 )

[0240] Using an Instron 5967 universal testing machine, the fracture load of the material was measured, and its fracture toughness KIC was determined to be:

[0241]

[0242] (a: notch depth, W: specimen height, f is a geometric correction factor)

[0243] 9. Coefficient of thermal expansion (×10) -6 / K)

[0244] Thermomechanical analysis (TMA): The change in sample length with temperature is measured in an inert atmosphere, and the average CTE (ΔL / L0ΔT) is calculated.

[0245] 10. Number of thermal shock cycles

[0246] Rapid cooling experiment: The sample was heated to the working temperature (800℃) and then rapidly cooled to room temperature. The number of cycles before cracking / peeling was observed.

[0247] 11.500h power attenuation rate (%)

[0248] Long-term stability test: A single cell was compared with an LSM (La) 0.8 Sr 0.2 A solid oxide fuel cell composed of MnO3 (lanthanum, strontium, and manganese oxide) was operated at 700°C with H2 (anode) and air (cathode) for 500 hours in constant current or constant voltage mode, and the power density decay (P0-P) was recorded. t ) / P0×100%.

[0249] 12. Interfacial resistance increase (%)

[0250] EIS time series analysis: periodically measure interfacial resistance (Rint) and calculate the growth rate (R). t -R0) / R0×100%).

[0251] 13. Interdiffusion coefficient of elements (×10) -16 cm 2 / s)

[0252] Diffusion couple experiment and EDS / SIMS: After high-temperature annealing, the concentration profile was analyzed by energy dispersive spectroscopy (EDS) or secondary ion mass spectrometry (SIMS), and the diffusion coefficient was fitted by Fick's second law.

[0253] 14. Phase transition temperature (°C)

[0254] Differential scanning calorimetry (DSC): Detecting endothermic / exothermic peaks to determine phase transition temperature.

[0255] The performance test data are summarized and plotted in Table 2:

[0256] Table 2. Performance test data of solid oxide fuel cell barrier layer

[0257]

[0258] In addition, to explore the effects of various additives during the formation of the barrier layer, comparative examples 11-23 were designed. The experimental methods, metal ratios, GDC dosage, YSZ dosage, and barrier layer thickness were the same as in Example 2, except that the amount of additives was changed. The specific contents are as follows:

[0259] Table 3. List of missing adjuvants

[0260]

[0261] Of the comparative examples 11-23 above, only comparative example 19 successfully formed a barrier layer. The other groups cracked or agglomerated during the slurry formation or casting process, resulting in failure to form a film. Although comparative example 19 successfully obtained a barrier layer, its ionic conductivity was only 0.052 S / cm and its bonding strength was only 36.6 MPa, indicating poor performance. The effects of each additive are speculated as shown in Table 3.

[0262] Table 3. Estimated Effects of Various Additives

[0263]

[0264] This invention, as a barrier layer material for solid oxide fuel cells (SOFCs), exhibits excellent performance in various aspects.

[0265] In terms of thermal stability, the phase transition temperatures of Examples 1, 2, and 3 are all above 1200°C, and the resistance increase is less than 10%, which proves that the element selection of the present invention is reasonable. The barrier layer material prepared under the element ratio of the present invention has a theoretical basis to serve as a barrier layer for SOFC.

[0266] Regarding the coefficient of thermal expansion, the CTE of the embodiment is 10-10.5×10⁻⁶. -6 The / K electrolyte is almost identical to the selected YSZ electrolyte sheet. The tight bonding between the two allows it to withstand more than 50 thermal shock cycles and has a power decay rate as low as 2.8% after 500 hours. If other electrolyte sheets are to be used, further research on the element ratio is required.

[0267] Regarding oxygen anion conductivity, when the Al molar ratio was 14.5% and the Ce molar ratio was 50% (Example 2), the material exhibited the best ionic conductivity (0.09 S / cm) and the lowest electronic conductivity (0.006 S / cm). On the one hand, Ce... 4+ / Ce 3+ The variable valence of oxygen promotes the migration of oxygen vacancies, which is why traditional barrier layer materials use cerium oxide-based materials. On the other hand, as mentioned earlier, the existence of high-entropy structures makes the diffusion path of oxygen ions in the material more diversified, enhances disordered movement, reduces activation energy, and creates an efficient diffusion barrier, enabling the material to have high oxygen negative ion conduction efficiency with an ionic conductivity (800℃) of 0.09 S / cm and an activation energy of only 0.82 eV.

[0268] Meanwhile, in suppressing Zr diffusion, 35.5% of rare earth elements significantly reduced the interdiffusion coefficient to 2 × 10⁻⁶ through lattice distortion effect (atomic size difference > 6%). -16 cm 2 / s, which is only 27% of that of the comparative example 3 without rare earth elements. This multi-element solid solution structure not only hinders element diffusion, but also increases the bonding strength to 40 MPa by increasing the overall configuration entropy of the material.

[0269] Example 2, with a HEO layer thickness of 3 μm and a substrate layer thickness of 12 μm, exhibited the best interfacial stability, with an interfacial resistance increase of only 7%, far lower than the control groups with excessively thin (1 μm) or excessively thick (10 μm) layers. This thickness combination ensured complete interfacial coverage while avoiding the increased ion transport resistance caused by excessive thickness. Notably, when the substrate layer thickness increased to 40 μm (Comparative Example 8), although the power density remained at 0.87 W / cm², the overall interfacial stability was significantly improved. 2 However, the number of thermal shock cycles dropped to 38, indicating that an excessively thick substrate layer would affect long-term stability due to the accumulation of thermal stress.

[0270] In summary, by using an optimized ratio of Al (14.5%), Ce (50%) and rare earth elements (35.5%), combined with a structural design of a 3μm alloy layer and a 12μm substrate layer, it is possible to simultaneously achieve high ionic conductivity (0.09S / cm), low interface degradation (resistance growth <8%), and excellent thermomechanical stability (thermal shock cycles >50).

[0271] This YSZ / GDC / HEO layer barrier layer provides an ideal solution for the long-term stable operation of SOFC through multi-scale composition-structure synergistic design.

[0272] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a solid oxide fuel cell barrier layer material, characterized in that, Includes the following steps: Preparation of S1 and YSZ / GDC matrix layers Preparation of S1.1, YSZ matrix green body: The YSZ slurry is cast onto an electrolyte sheet to form a thin film, and then dried at 60-80℃ for 12-24 hours to ensure complete drying, thus obtaining a YSZ matrix layer green body. S1.2 Preparation of GDC matrix green body: GDC slurry is cast into a thin film on a YSZ substrate green body and dried at 60-80℃ for 12-24 hours to ensure complete drying, thus obtaining a GDC substrate green body. S1.3, Lamination and Co-sintering: The GDC matrix green blank, YSZ matrix green blank, electrolyte sheet, and anode sheet are stacked, vacuum sealed, and isostatically pressed at 50 MPa for 20 min at 70°C to obtain the composite green blank. After sintering the composite green body, a single-cell blank containing a YSZ / GDC matrix layer is formed. S2, Preparation of alloy slurry S2.1 Preprocessing: After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, metal powders with a particle size of less than 1 μm were obtained. S2.2 Preparation of alloy slurry: Metals La, Ce, Nd, Gd, Co, Cu, and Al were mixed in a specific molar ratio. Polyvinyl butyral and dibutyl phthalate were added, and the mixture was ball-milled for 24 hours under the same conditions. After filtration, the mixture was vacuum degassed for 30 minutes to obtain a high-entropy alloy (La). 1 / 5 Nd 1 / 5Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z Alloy slurry, wherein 40≤y≤60, 11.5≤z≤17.5, x+y+z=100; Preparation of S3 and HEO layers The high-entropy alloy (La) was applied using a drop-coating method. 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z The alloy slurry was dripped onto the surface of the YSZ / GDC substrate layer of the single cell blank. After being evenly coated, it was dried at 60°C for 2 hours to obtain the single cell blank. The single-cell blank was sintered a second time using a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The program was set as follows: ① Heating from room temperature to 400℃ at a heating rate of 1-2℃ / min, followed by vacuum sintering; ② Increase the temperature to 800℃ at a heating rate of 3℃ / min, hold for 1 hour, and then vacuum sinter; ③ The temperature was further increased to 1200℃ at a heating rate of 2℃ / min, held for 4 hours, and then vacuum sintered. ④ The sample is cooled in the furnace under a mixed atmosphere of 7% oxygen and 93% nitrogen, and the cooling rate is controlled to be no more than 5℃ / min. A single cell containing a high-entropy alloy oxide (HEO) layer was obtained.

2. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO / YSZ composite anode.

3. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The preparation process of the YSZ slurry is as follows: after pretreatment of YSZ powder, anhydrous ethanol and anhydrous triethanolamine are added and mixed and ball-milled for 24 hours to obtain YSZ composite powder suspension. Add polyvinyl butyral and dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and degas under vacuum for 30 minutes to obtain YSZ slurry. The mass ratio of YSZ powder, starch powder, solvents anhydrous ethanol, anhydrous triethanolamine, polyvinyl butyral, and dibutyl phthalate is 100:2-4:160-240:8-12:9-11:2-5. Where YSZ refers to Y 0.16 Zr 0.92 O2, i.e., yttrium-doped zirconium oxide.

4. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The preparation process of the GDC slurry is as follows: CeO2 powder, Gd2O3 powder, anhydrous ethanol and ammonium polyacrylate are mixed and ball-milled for 24 hours, dried at 60-80℃ for 12-24 hours, and passed through a 200-mesh sieve to obtain GDC composite powder. After calcining the GDC composite powder, anhydrous ethanol, polyvinyl butyral and dibutyl phthalate were added, and the mixture was ball-milled for 24 hours. After filtration, the mixture was degassed under vacuum for 30 minutes to obtain the GDC slurry. The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:350-450:1-3:15-25:5-7. GDC refers to Ce 0.90 Gd 0.10 O 1.95 That is, gadolinium-doped cerium oxide.

5. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: In step S1.3, the specific steps for sintering the composite green body are as follows: The composite green body was laid flat on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multi-functional vacuum sintering furnace. The sintering atmosphere was air, and the program was set as follows: ① Heat from room temperature to 600℃ at a heating rate of 2℃ / min and hold for 4 hours; ② Increase the temperature from 600℃ to 1000℃ at a rate of 5℃ / min and hold for 1 hour; ③ Increase the temperature from 1000℃ to 1400℃ at a rate of 2℃ / min and hold for 4 hours; ④ During cooling, the cooling rate should be ≤5℃ / min, and the product should be removed when the temperature drops below 200℃; In the matrix layer, the thickness ratio of the YSZ matrix green and the GDC matrix green is 1:1; the thickness of the YSZ / GDC matrix layer obtained by S1 is 8-16 μm.

6. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The specific process of the S2.1 preprocessing is as follows: After pretreatment of metals La, Ce, Nd, Gd, Co, Cu and Al respectively, they are placed into the tungsten carbide cemented carbide ball mill jar of QM-3SP4 planetary ball mill. Grinding balls are weighed at a ball-to-material ratio of 15:1 and placed into the ball mill jar. Anhydrous ethanol and anhydrous triethanolamine are added. The atmosphere was kept as high-purity Ar through three vacuum-gas cycles, with a final pressure of 0.5 MPa. The ball mill was run at 350 rpm for 24 hours to obtain a suspension. The suspension was placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes. The suspension was then cooled in a water bath to maintain a temperature below 40°C. After ultrasonication, the suspension was centrifuged at 3000 rpm for 10 minutes. The supernatant was then placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain metal powder with a particle size of less than 1 μm.

7. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The mass ratio of high-entropy alloy, anhydrous ethanol, anhydrous triethanolamine, polyvinyl butyral, and dibutyl phthalate in S2 is 100:160-240:15-25:8-12:2-4.

8. The method for preparing a solid oxide fuel cell barrier layer material according to claim 1, characterized in that: The thickness of the high-entropy alloy oxide (HEO) layer obtained by S3 is 2-4 μm.

9. A solid oxide fuel cell barrier layer material prepared by any one of the preparation methods described in claims 1-8, characterized in that, It includes a YSZ / GDC matrix layer and a high-entropy alloy oxide (HEO) layer.

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