Solid oxide fuel cell barrier layer material and preparation method thereof

Abstract

The invention discloses a barrier layer material of a solid oxide fuel cell and a preparation method of the barrier layer material. The preparation method comprises the following steps: (1) preparing a YSZ / GDC substrate layer; (2) preparing alloy slurry; and (3) preparing the HEO layer. According to the invention, high-entropy oxide design is utilized to form a high-entropy structure with serious lattice distortion and diversified chemical environments; the rare earth / transition metal ratio is optimized, and the thermal expansion coefficient of the barrier layer is accurately controlled; the thickness of the YSZ / GDC matrix layer / HEO layer is regulated and controlled, so that a barrier layer material which can remarkably inhibit element diffusion and has high ionic conductivity is obtained; the problems that a traditional barrier layer is high in interface resistance and poor in long-term stability are effectively solved, a reliable material basis is provided for efficient and stable operation of the SOFC, and important industrial application value is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells, and in particular to a solid oxide fuel cell barrier layer material and a preparation method thereof. Background Art

[0002] Solid oxide fuel cell (SOFC) is a power generation device that directly converts chemical energy into electrical energy. A typical solid oxide fuel cell consists of a three-layer structure of cathode / electrolyte / anode.

[0003] However, the cathode materials currently used have poor chemical compatibility with the most widely used and most mature zirconia-based electrolytes, such as YSZ (yttrium-doped zirconia) and ScSZ (scandium-doped zirconia). They are prone to chemical reactions with the zirconia-based electrolyte during the sintering and operation of the cathode, generating high-resistance phase impurities at the interface between the cathode and the electrolyte, causing the battery performance to degrade sharply. In addition, the thermal expansion properties of the cathode and the zirconia-based electrolyte are quite different, and the cathode may fall off the electrolyte under multiple temperature cycles.

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

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

[0006] Therefore, the barrier layer material of SOFC must have the ability to block the diffusion of Zr elements between the electrolyte and the electrode, match the thermal expansion coefficient (CTE) with the electrolyte, and be able to conduct O efficiently. 2- And the ability to operate stably at high temperatures. 2- Barrier materials that are conductive and stable at high temperatures are still being explored. Summary of the Invention

[0007] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a solid oxide fuel cell barrier layer material and a preparation method thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

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

[0010] S1. Preparation of YSZ / GDC substrate layer

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

[0012] Cast the YSZ slurry into a thin film on the electrolyte sheet, and dry it at 60-80°C for 12-24 hours to ensure complete drying to obtain a YSZ matrix layer green body;

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

[0014] Cast the GDC slurry into a thin film on the YSZ substrate green body, and dry it at 60-80℃ for 12-24h to ensure complete drying to obtain the GDC substrate green body;

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

[0016] The GDC substrate layer green body, the YSZ substrate layer green body, the electrolyte sheet, and the anode sheet were stacked, vacuum sealed, and isostatically pressed at 70°C and a pressure of 50 MPa for 20 minutes to obtain a composite green body;

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

[0018] S2. Preparation of alloy slurry

[0019] S2.1, Preprocessing:

[0020] After pre-treating metals La, Ce, Nd, Gd, Co, Cu and Al, metal powders with a particle size of less than 1 μm are obtained;

[0021] S2.2. Preparation of alloy slurry:

[0022] The metals La, Ce, Nd, Gd, Co, Cu and Al were mixed in a certain molar ratio, polyvinyl butyral and dibutyl phthalate were added, and ball milling was continued for 24 hours under the same conditions. After filtration, vacuum degassing was carried out 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, where 40≤y≤60, 11.5≤z≤17.5, x+y+z=100;

[0023] S3. Preparation of HEO layer

[0024] The high entropy alloy (La 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 YSZ / GDC substrate surface of the single cell blank, evenly coated, and then dried at 60°C for 2 hours to obtain the single cell blank.

[0025] The single cell blanks were sintered twice in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The program settings were as follows:

[0026] ①Heat from room temperature to 400℃ at a heating rate of 1-2℃ / min and sinter in vacuum;

[0027] ② Raise the temperature to 800℃ at a heating rate of 3℃ / min, keep warm for 1h, and sinter in vacuum;

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

[0029] ③ The temperature was further increased to 1200°C at a heating rate of 2°C / min, kept at this temperature for 4 hours, and vacuum sintered;

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

[0031] ④ The sample is cooled in the furnace in an atmosphere of a mixture of 7% oxygen and 93% nitrogen, and the cooling rate is controlled at no more than 5°C / min.

[0032] The introduction of oxygen during the formation of the film promotes the formation of metal oxides. The reference "Study on the Effect of High Entropy Alloys and Their Oxide Films on Cu-Si Diffusion Barrier" studies the transformation of high entropy alloys into high entropy oxides. When the oxygen concentration is 7%, the elements on the surface of the prepared film are evenly distributed without large-scale loss or agglomeration, and the film quality is good.

[0033] A single cell containing a high entropy alloy oxide (HEO) layer is 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 pre-treating the YSZ powder, anhydrous ethanol and anhydrous triethanolamine as a dispersant are added and mixed and ball-milled for 24 hours to obtain a 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 h. After filtration, vacuum degassing was performed for 30 min to obtain a 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, that is, 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°C for 12-24 hours, and passed through a 200-mesh sieve to obtain a 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, filtered and vacuum-degassed for 30 minutes to obtain a GDC slurry.

[0041] The mass ratio of CeO2 powder to 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 of sintering the composite green body are as follows:

[0044] The composite green body was spread on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The sintering atmosphere was air and the program settings were as follows:

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

[0046] ②Heating from 600℃ to 1000℃ at a rate of 5℃ / min and keeping warm for 1h;

[0047] ③Heating from 1000℃ to 1400℃ at a rate of 2℃ / min and keeping warm for 4h;

[0048] ④ When cooling, the cooling rate is ≤5℃ / min, and it is taken out when the temperature is below 200℃;

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

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

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

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

[0053] Through three vacuum-inflation cycles, the atmosphere is ensured to be high-purity Ar with a final pressure of 0.5 MPa; the suspension is obtained by grinding at a speed of 350 rpm and a ball milling time of 24 hours. The suspension is placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes, and cooled in a water bath to maintain the temperature <40°C; after the ultrasonication is completed, the suspension is placed in a centrifuge and centrifuged at a speed of 3000 rpm for 10 minutes. The supernatant is placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a metal powder with a particle size of less than 1 μm.

[0054] Preferably, the mass ratio of the 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 prepared high entropy alloy oxide HEO layer is 2-4 μm.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] 1. Higher density and thermal stability

[0058] In addition to adding a dense HEO layer to the traditional GDC layer, the present invention adopts a gradient sintering method during sintering, so that Al with a smaller atomic radius can penetrate between CeO2 molecules at 800°C. When vacuum sintered 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 gaps between grains to enhance solid solution strengthening, improve the film-base bonding strength, and thus improve the density of the film.

[0059] For the GDC layer, the introduction of oxygen causes Al to oxidize 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 working as a barrier layer, the phase change temperature of the present invention is maintained above 1200° C., which is well above the normal operating temperature of SOFC.

[0061] 2. Adjustable thermal expansion coefficient

[0062] The mixing of different CTEs in the materials produces a local strain field, which in turn offsets 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 the present invention can be precisely controlled by composition design to match that of the electrolyte (the CTE of YSZ is 10.5×10 -6 / K, the present invention is made of 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 HEO layer obtained is 10×10 -6 / K) is highly matched, avoiding the barrier layer from falling off due to CTE imbalance.

[0063] 3. High oxygen negative ion conduction efficiency

[0064] The barrier layer has a high-entropy structure that facilitates the migration of oxygen anions. Its crystal structure lacks a distinct ordered arrangement, making the diffusion paths of oxygen ions within the material more diverse. This allows oxygen ions to migrate through different channels and locations, reducing mutual obstruction between them and increasing their migration rate.

[0065] Furthermore, due to the presence of a large number of 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 promotes the disordered movement of oxygen ions, lowering activation energy while creating a highly efficient diffusion barrier, reducing the activation energy of oxygen ion migration to 0.82 eV and enabling the material to achieve high oxygen negative ion conduction efficiency.

[0066] 4. Vacancy regulation blocks Zr element diffusion

[0067] Zr diffusion essentially forms a new phase in the barrier layer or cathode material. The formation of a new phase requires the coordinated diffusion of many atoms to achieve elemental redistribution. The size differences of the various atoms in the HEO layer of this barrier layer cause severe lattice distortion in the material, resulting in significantly different elemental diffusion pathways and activation energies compared to traditional materials.

[0068] In traditional barrier layers, Zr can generate stable high-resistance phase impurities at the cathode-electrolyte interface. This stability makes SOFC tend to generate impurities when operating at high temperatures.

[0069] In the present invention, however, the reactivity of each element with Zr is not high, and because the atoms around each lattice point in the HEO layer are different, after Zr migrates to the vacant position, the atoms adjacent to it are different. The atomic bonding at different lattice points is different, and the binding energy at different lattice points is also different. This results in Zr being "trapped" when it migrates to a low-energy lattice point, and the probability of subsequent migration from this position will also be reduced. The large fluctuations in the lattice potential energy between lattice points cause the diffusion of elements in the barrier layer to be relatively slow, and a large number of low lattice potential energy lattice points restrict and hinder the diffusion of atoms, 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, the present invention adds a layer of HEO with precisely controlled CTE to the existing GDC barrier layer material, so that the barrier layer has high density and high thermal stability, CTE matching the electrolyte layer, high O 2- The conduction efficiency and the ability to block the diffusion of Zr elements provide a reliable material basis for the efficient and stable operation of SOFC and have important industrial application value. DETAILED DESCRIPTION

[0072] Figure 1 This is a process flow chart for producing the solid oxide fuel cell barrier layer material of the present invention. The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0073] Example 1:

[0074] A method for preparing a barrier layer material for a solid oxide fuel cell comprises the following steps:

[0075] S1. Preparation of YSZ / GDC substrate layer

[0076] S1.1. Preparation of YSZ substrate green body:

[0077] After pretreatment, 100 g of YSZ powder was added with anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant, and the mixture was ball-milled for 24 h to obtain a YSZ composite powder suspension;

[0078] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain YSZ slurry;

[0079] The YSZ slurry was cast into a thin film on the electrolyte sheet and dried in an oven at 60°C for 24 hours to ensure complete drying to obtain a YSZ matrix layer green body;

[0080] S1.2. Preparation of GDC substrate green body:

[0081] 89.5 g of CeO2 powder and 10.5 g of Gd2O3 powder, solvent anhydrous ethanol, and dispersant ammonium polyacrylate were mixed and ball-milled for 24 h, then dried in an oven at 60 °C for 24 h and passed through a 200-mesh sieve to obtain GDC composite powder;

[0082] After calcining the GDC composite powder, anhydrous ethanol as solvent, polyvinyl butyral as binder, and dibutyl phthalate as plasticizer were added, and the mixture was ball-milled for 24 hours, filtered, and vacuum-degassed for 30 minutes to obtain a GDC slurry.

[0083] The GDC slurry was cast into a thin film on the YSZ substrate layer green body, and dried in a 60°C oven for 24 hours to ensure complete drying, thereby obtaining a GDC substrate layer green body;

[0084] S1.3, Lamination and Co-sintering:

[0085] The GDC substrate layer green body, the YSZ substrate layer green body, the electrolyte sheet, and the anode sheet were stacked, vacuum sealed, and isostatically pressed at 70°C and a pressure of 50 MPa for 20 minutes to obtain a composite green body;

[0086] After sintering the composite green body, a single cell rough body containing a YSZ / GDC matrix layer is formed;

[0087] 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 slurry

[0088] S2.1, Preprocessing:

[0089] After pre-treatment, metals La, Ce, Nd, Gd, Co, Cu and Al were placed in the tungsten carbide ball mill of the QM-3SP4 planetary ball mill. Grinding balls were weighed according to the ball-to-material ratio of 15:1 and placed in the ball mill. The solvent anhydrous ethanol and the dispersant anhydrous triethanolamine were added.

[0090] The mixture was subjected to three vacuum-inflating cycles to ensure that the atmosphere was high-purity Ar and the final pressure was 0.5 MPa. The mixture was ground at a speed of 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 cooled in a water bath to maintain the temperature below 40°C. After the ultrasonication, the suspension was placed in a centrifuge and centrifuged at a speed of 3000 rpm for 10 minutes. The supernatant was placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a metal powder with a particle size of less than 1 μm.

[0091] S2.2. Preparation of alloy slurry:

[0092] The metal powders of La, Ce, Nd, Gd, Co, Cu and Al, including 4.7g of Al, 56.0g of Ce, 7.1g of La, 11.8g of Nd, 12.3g of Gd, 5.0g of Co and 5.4g of Cu, were mixed, and anhydrous ethanol, anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer were added. The mixture was ball milled for 24h under the same conditions, filtered and vacuum degassed for 30min 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 slurry;

[0093] S3. Preparation of HEO layer

[0094] The high entropy alloy (La 1 / 5 Nd1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z The alloy slurry is dripped onto the surface of the substrate layer, evenly coated, and then dried at 60°C for 2 hours to obtain a single cell blank.

[0095] The single cell blanks were sintered twice in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The program settings were as follows:

[0096] ① Heating from room temperature to 400℃ at a heating rate of 2℃ / min and vacuum sintering;

[0097] ② Raise the temperature to 800℃ at a heating rate of 3℃ / min, keep warm for 1h, and sinter in vacuum;

[0098] ③ The temperature was further increased to 1200°C at a heating rate of 2°C / min, kept at this temperature for 4 hours, and vacuum sintered;

[0099] ④ The sample was cooled in the furnace in an atmosphere of a mixture of 7% oxygen and 93% nitrogen, and the cooling rate was controlled at 5°C / min.

[0100] A single cell containing a high entropy alloy oxide (HEO) layer is obtained by secondary sintering.

[0101] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0102] 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.

[0103] The mass ratio of CeO2 powder to Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:350:3:15:7.

[0104] The specific steps of sintering the composite green body are as follows:

[0105] The composite green body was spread on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The sintering atmosphere was air and the program settings were as follows:

[0106] ①Heat from room temperature to 600℃ at a heating rate of 2℃ / min and keep warm for 4h;

[0107] ②Heating from 600℃ to 1000℃ at a rate of 5℃ / min and keeping warm for 1h;

[0108] ③Heating from 1000℃ to 1400℃ at a rate of 2℃ / min and keeping warm for 4h;

[0109] ④ When cooling, the cooling rate is 5℃ / min, and it is taken out when the temperature is below 200℃;

[0110] The thickness ratio of the YSZ substrate layer green body and the GDC substrate layer green body is 1:1.

[0111] The sintering program is set to match the requirements of organic matter decomposition (600℃), initial grain growth (1000℃) and densification (1400℃) to avoid cracking of the green body.

[0112] The thickness of the prepared base layer is 8 μm.

[0113] 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.

[0114] The thickness of the prepared metal oxide layer is 4 μm.

[0115] Example 2:

[0116] A method for preparing a barrier layer material for a solid oxide fuel cell comprises the following steps:

[0117] S1. Preparation of YSZ / GDC substrate layer

[0118] S1.1. Preparation of YSZ substrate green body:

[0119] After pre-treating 150 g of YSZ powder, anhydrous ethanol as a solvent and anhydrous triethanolamine as a dispersant were added and mixed and ball-milled for 24 h to obtain a YSZ composite powder suspension;

[0120] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain YSZ slurry;

[0121] The YSZ slurry was cast into a thin film on the electrolyte sheet and dried at 60°C for 24 hours to ensure complete drying to obtain a YSZ matrix layer green body;

[0122] S1.2. Preparation of GDC substrate green body:

[0123] 134.3 g of CeO2 powder, 15.7 g of Gd2O3 powder, solvent anhydrous ethanol, and dispersant ammonium polyacrylate were mixed and ball-milled for 24 h, then dried in an oven at 60 °C for 24 h and passed through a 200-mesh sieve to obtain GDC composite powder;

[0124] After calcining the GDC composite powder, anhydrous ethanol as solvent, polyvinyl butyral as binder, and dibutyl phthalate as plasticizer were added, and the mixture was ball-milled for 24 hours, filtered, and vacuum-degassed for 30 minutes to obtain a GDC slurry.

[0125] The GDC slurry was cast into a thin film on the YSZ substrate layer green body, and dried in a 60°C oven for 24 hours to ensure complete drying, thereby obtaining a GDC substrate layer green body;

[0126] S1.3, Lamination and Co-sintering:

[0127] The GDC substrate layer green body, the YSZ substrate layer green body, the electrolyte sheet, and the anode sheet were stacked, vacuum sealed, and isostatically pressed at 70°C and a pressure of 50 MPa for 20 minutes to obtain a composite green body;

[0128] After sintering the composite green body, a single cell rough body containing a YSZ / GDC matrix layer is formed;

[0129] 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 slurry

[0130] S2.1, Preprocessing:

[0131] After pre-treatment, metals La, Ce, Nd, Gd, Co, Cu and Al were placed in the tungsten carbide ball mill of the QM-3SP4 planetary ball mill. Grinding balls were weighed according to the ball-to-material ratio of 15:1 and placed in the ball mill. The solvent anhydrous ethanol and the dispersant anhydrous triethanolamine were added.

[0132] The mixture was subjected to three vacuum-inflating cycles to ensure that the atmosphere was high-purity Ar and the final pressure was 0.5 MPa. The mixture was ground at a speed of 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 cooled in a water bath to maintain the temperature below 40°C. After the ultrasonication, the suspension was placed in a centrifuge and centrifuged at a speed of 3000 rpm for 10 minutes. The supernatant was placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a metal powder with a particle size of less than 1 μm.

[0133] S2.2. Preparation of alloy slurry:

[0134] 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, and anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer were added. The mixture was ball milled for 24 h under the same conditions, filtered and vacuum degassed for 30 min 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 slurry;

[0135] S3. Preparation of HEO layer

[0136] The high entropy alloy (La 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z The alloy slurry is dripped onto the surface of the substrate layer, evenly coated, and then dried at 60°C for 2 hours to obtain a single cell blank.

[0137] The single cell blanks were sintered twice in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The program settings were as follows:

[0138] ①Heat from room temperature to 400℃ at a heating rate of 1-2℃ / min and sinter in vacuum;

[0139] ② Raise the temperature to 800℃ at a heating rate of 3℃ / min, keep warm for 1h, and sinter in vacuum;

[0140] ③ The temperature was further increased to 1200°C at a heating rate of 2°C / min, kept at this temperature for 4 hours, and vacuum sintered;

[0141] ④ The sample was cooled in the furnace in an atmosphere of a mixture of 7% oxygen and 93% nitrogen, and the cooling rate was controlled at 5°C / min.

[0142] A single cell containing a high entropy alloy oxide (HEO) layer is obtained by secondary sintering.

[0143] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0144] The mass ratio of YSZ powder, starch powder, solvent anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:3:100:10:10:3.5.

[0145] The mass ratio of CeO2 powder to Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:400:2:20:6.

[0146] The specific steps of sintering the composite green body are as follows:

[0147] The composite green body was spread on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The sintering atmosphere was air and the program settings were as follows:

[0148] ①Heat from room temperature to 600℃ at a heating rate of 2℃ / min and keep warm for 4h;

[0149] ②Heating from 600℃ to 1000℃ at a rate of 5℃ / min and keeping warm for 1h;

[0150] ③Heating from 1000℃ to 1400℃ at a rate of 2℃ / min and keeping warm for 4h;

[0151] ④ When cooling, the cooling rate is 5℃ / min, and it is taken out when the temperature is below 200℃;

[0152] The thickness ratio of the YSZ substrate layer green body and the GDC substrate layer green body is 1:1.

[0153] The sintering program is set to match the requirements of organic matter decomposition (600℃), initial grain growth (1000℃) and densification (1400℃) to avoid cracking of the green body.

[0154] The thickness of the prepared substrate layer is 12 μm.

[0155] 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.

[0156] The thickness of the prepared metal oxide layer is 3 μm.

[0157] Example 3:

[0158] A method for preparing a barrier layer material for a solid oxide fuel cell comprises the following steps:

[0159] S1. Preparation of YSZ / GDC substrate layer

[0160] S1.1. Preparation of YSZ substrate green body:

[0161] After pretreatment, 200 g of YSZ powder was added with anhydrous ethanol as solvent and anhydrous triethanolamine as dispersant, and the mixture was ball-milled for 24 h to obtain a YSZ composite powder suspension;

[0162] Add the binder polyvinyl butyral and the plasticizer dibutyl phthalate to the YSZ composite powder suspension, continue ball milling for 24 hours, filter and vacuum degas for 30 minutes to obtain YSZ slurry;

[0163] The YSZ slurry was cast into a thin film on the electrolyte sheet and dried in an oven at 60°C for 24 hours to ensure complete drying to obtain a YSZ matrix layer green body;

[0164] S1.2. Preparation of GDC substrate green body:

[0165] 179.1 g of CeO2 powder, 20.9 g of Gd2O3 powder, solvent anhydrous ethanol, and dispersant ammonium polyacrylate were mixed and ball-milled for 24 h, then dried in an oven at 60 °C for 24 h and passed through a 200-mesh sieve to obtain GDC composite powder;

[0166] After calcining the GDC composite powder, anhydrous ethanol as solvent, polyvinyl butyral as binder, and dibutyl phthalate as plasticizer were added, and the mixture was ball-milled for 24 hours, filtered, and vacuum-degassed for 30 minutes to obtain a GDC slurry.

[0167] The GDC slurry was cast into a thin film on the YSZ substrate layer green body, and dried in a 60°C oven for 24 hours to ensure complete drying, thereby obtaining a GDC substrate layer green body;

[0168] S1.3, Lamination and Co-sintering:

[0169] The GDC substrate layer green body, the YSZ substrate layer green body, the electrolyte sheet, and the anode sheet were stacked, vacuum sealed, and isostatically pressed at 70°C and a pressure of 50 MPa for 20 minutes to obtain a composite green body;

[0170] After sintering the composite green body, a single cell rough body containing a YSZ / GDC matrix layer is formed;

[0171] 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 slurry

[0172] S2.1, Preprocessing:

[0173] After pre-treatment, metals La, Ce, Nd, Gd, Co, Cu and Al were placed in the tungsten carbide ball mill of the QM-3SP4 planetary ball mill. Grinding balls were weighed according to the ball-to-material ratio of 15:1 and placed in the ball mill. The solvent anhydrous ethanol and the dispersant anhydrous triethanolamine were added.

[0174] The mixture was subjected to three vacuum-inflating cycles to ensure that the atmosphere was high-purity Ar and the final pressure was 0.5 MPa. The mixture was ground at a speed of 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 cooled in a water bath to maintain the temperature below 40°C. After the ultrasonication, the suspension was placed in a centrifuge and centrifuged at a speed of 3000 rpm for 10 minutes. The supernatant was placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a metal powder with a particle size of less than 1 μm.

[0175] S2.2. Preparation of alloy slurry:

[0176] 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, and anhydrous ethanol as solvent, polyvinyl butyral as binder and dibutyl phthalate as plasticizer were added. The mixture was ball milled for 24 h under the same conditions, filtered and vacuum degassed for 30 min 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 slurry;

[0177] S3. Preparation of a single cell containing a substrate layer / HEO (high entropy oxide) barrier layer

[0178] The high entropy alloy (La 1 / 5 Nd 1 / 5 Gd 1 / 5 Co 1 / 5 Cu 1 / 5 ) x Ce y Al z The alloy slurry is dripped onto the surface of the substrate layer, evenly coated, and then dried at 60°C for 2 hours to obtain a single cell blank.

[0179] The single cell blanks were sintered twice in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The program settings were as follows:

[0180] ①Heat from room temperature to 400℃ at a heating rate of 1-2℃ / min and sinter in vacuum;

[0181] ② Raise the temperature to 800℃ at a heating rate of 3℃ / min, keep warm for 1h, and sinter in vacuum;

[0182] ③ The temperature was further increased to 1200°C at a heating rate of 2°C / min, kept at this temperature for 4 hours, and vacuum sintered;

[0183] ④ The sample was cooled in the furnace in an atmosphere of a mixture of 7% oxygen and 93% nitrogen, and the cooling rate was controlled at 5°C / min.

[0184] A single cell containing a high entropy alloy oxide (HEO) layer is obtained by secondary sintering.

[0185] The electrolyte sheet is a YSZ electrolyte sheet, and the anode sheet is a NiO (nickel oxide) / YSZ composite anode.

[0186] The mass ratio of YSZ powder, starch powder, solvent anhydrous ethanol, dispersant anhydrous triethanolamine, binder polyvinyl butyral, and plasticizer dibutyl phthalate is 100:4:80:12:9:5.

[0187] The mass ratio of CeO2 powder and Gd2O3 powder, anhydrous ethanol, ammonium polyacrylate, polyvinyl butyral, and dibutyl phthalate is 200:450:1:25:5.

[0188] The specific steps of sintering the composite green body are as follows:

[0189] The composite green body was spread on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The sintering atmosphere was air and the program settings were as follows:

[0190] ①Heat from room temperature to 600℃ at a heating rate of 2℃ / min and keep warm for 4h;

[0191] ②Heating from 600℃ to 1000℃ at a rate of 5℃ / min and keeping warm for 1h;

[0192] ③Heating from 1000℃ to 1400℃ at a rate of 2℃ / min and keeping warm for 4h;

[0193] ④ When cooling, the cooling rate is 5℃ / min, and it is taken out when the temperature is below 200℃;

[0194] The thickness ratio of the YSZ substrate layer green body and the GDC substrate layer green body is 1:1.

[0195] The sintering program is set to match the requirements of organic matter decomposition (600℃), initial grain growth (1000℃) and densification (1400℃) to avoid cracking of the green body.

[0196] The thickness of the prepared substrate layer is 16 μm.

[0197] 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.

[0198] The thickness of the prepared metal oxide layer is 2 μm.

[0199] Also designed accordingly:

[0200] Comparative Example 1: The formulation and experimental method are the same as those of Example 2, but without adding Al;

[0201] Comparative Example 2: The formulation and experimental method are the same as those in Example 2, but with the addition of excess Al;

[0202] Comparative Example 3: The formulation and experimental method are the same as those in Example 2, but Ce is not added;

[0203] Comparative Example 4: The formulation and experimental method are the same as those in Example 2, but an excess of Ce is added;

[0204] Comparative Example 5: The formulation and experimental method are the same as those of Example 2, but without the addition of La, Gd, Nd, Co, and Cu;

[0205] Comparative Example 6: The formulation and experimental method are the same as those in Example 2, but excess La, Gd, Nd, Co, and Cu are added;

[0206] Comparative Example 7: The formulation and experimental method are the same as those of Example 2, but without adding YSZ powder, CeO2 powder, and Gd2O3 powder;

[0207] Comparative Example 8: The formulation and experimental method are the same as those in Example 2, but excess YSZ powder, CeO2 powder, and Gd2O3 powder are added;

[0208] Comparative Example 9: The element ratio and experimental method are the same as those in Example 2, but only a 1 μm alloy layer is prepared;

[0209] Comparative Example 10: The formulation and experimental method are the same as those in Example 2, but a 10 μm alloy layer is prepared;

[0210] The specific formula and test method are shown in Table 1:

[0211] Table 1. Formulation of barrier layers in solid oxide fuel cells

[0212]

[0213] The specific performance tests were carried out on each embodiment and comparative example, and the test methods and corresponding results are shown below:

[0214] 1. Ionic conductivity (800°C, S / cm)

[0215] Electrochemical impedance spectroscopy (EIS): Using the two-electrode method, platinum (Pt) was used as the electrode material to form a battery with a single cell. The impedance spectra at different frequencies (0.1 Hz-1 MHz) were measured at 800°C, and the bulk resistance (Rb) and grain boundary resistance (Rgb) were obtained by Nyquist plot fitting.

[0216]

[0217] Where L is the thickness and A is the electrode area.

[0218] 2. Electronic conductivity (800℃, S / cm)

[0219] DC four-probe method: eliminates the influence of contact resistance, directly measures electronic conductivity, uses platinum (Pt) as the electrode material, and forms a battery with a single cell to ensure the accuracy of electron transmission.

[0220] 3. Activation energy (eV)

[0221] Variable temperature impedance spectroscopy: The electrical conductivity was measured at different temperatures (600-800°C), and the activation energy Ea was fitted using the Arrhenius formula.

[0222]

[0223] Here, σ0 represents the 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 its unit is electron volt (eV).

[0224] k is the Boltzmann constant, which is approximately 1.38×10 −23 J / K.

[0225] T is the absolute temperature, measured in Kelvin (K).

[0226] 4. Open circuit voltage (OCV, 700°C, V)

[0227] Fuel cell test system: Single cell and LSM (La 0.8 Sr 0.2MnO3, lanthanum strontium manganese oxide) is composed of a solid oxide fuel cell. At 700°C, H2 (anode) and air (cathode) are introduced. The OCV under no-load condition is directly measured with a high-impedance voltmeter to verify the airtightness of the barrier layer (the ideal value is close to the Nernst voltage).

[0228] 5. Maximum power density (750℃, W / cm 2 )

[0229] IV / PV curve test: compare single cell with LSM (La 0.8 Sr 0.2 MnO3, lanthanum strontium manganese oxide) composed of a solid oxide fuel cell, at 700 ° C, H2 (anode) and air (cathode) were introduced, at 750 ° C, the current-voltage curve was recorded by an electrochemical workstation, and the power density P was calculated, taking the maximum value.

[0230]

[0231] Where A is the electrode area.

[0232] 6. Bond strength (MPa)

[0233] Tensile / shear test: After bonding the barrier layer to the electrolyte or electrode layer, perform a shear test using a universal testing machine and record the breaking strength.

[0234] 7. Hardness (GPa)

[0235] Nanoindentation: Using a Berkovich indenter, the hardness H is calculated from the load-displacement curve.

[0236]

[0237] Where Ac is the contact area.

[0238] 8. Fracture toughness (MPa·m 1 / 2 )

[0239] The fracture load of the material is measured using an Instron 5967 universal testing machine, and its fracture toughness KIC is

[0240]

[0241] (a: notch depth, W: specimen height, f: geometric correction factor)

[0242] 9. Thermal expansion coefficient (×10 -6 / K)

[0243] Thermomechanical Analysis (TMA): The change in sample length with temperature was measured in an inert atmosphere, and the average CTE (ΔL / L0ΔT) was calculated.

[0244] 10. Number of thermal shock cycles

[0245] Rapid cooling test: The sample is heated to the operating temperature (800°C) and then rapidly cooled to room temperature to observe the number of cycles before cracking / peeling.

[0246] 11.500h power attenuation rate (%)

[0247] Long-term stability test: The single cell is tested with LSM (La 0.8 Sr 0.2 MnO3, lanthanum strontium manganese oxide) composed of solid oxide fuel cells, at 700 ° C, with H2 (anode) and air (cathode), under constant current or constant voltage mode for 500 h, record the power density decay ((P0-P t ) / P0×100%).

[0248] 12.Interface resistance growth (%)

[0249] EIS time series analysis: regularly measure the interface resistance (Rint) and calculate the growth rate (R t -R0) / R0×100%).

[0250] 13. Interdiffusion coefficient of elements (×10 -16 cm 2 / s)

[0251] Diffusion couple experiment and EDS / SIMS: After high-temperature annealing, the concentration profile is analyzed by energy dispersive spectroscopy (EDS) or secondary ion mass spectrometry (SIMS), and the diffusion coefficient is fitted using Fick's second law.

[0252] 14. Phase transition temperature (℃)

[0253] Differential Scanning Calorimetry (DSC): Detect endothermic / exothermic peaks to determine phase transition temperatures.

[0254] The performance test data are summarized and plotted into Table 2:

[0255] Table 2. Performance test data of solid oxide fuel cell barrier layer

[0256]

[0257] In addition, to explore the effects of various additives on the barrier layer formation process, comparative examples 11-23 were designed. The test methods, metal ratios, GDC dosages, YSZ dosages, and barrier layer thicknesses were the same as those in Example 2, with only the additive amounts being varied. The specific contents are as follows:

[0258] Table 3. Missing status of each additive

[0259]

[0260] Among the above comparative examples 11-23, only comparative example 19 successfully formed a barrier layer, while the other groups all cracked or agglomerated during the slurrying or salivation process, so that no film was formed. 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 the additives are speculated as shown in Table 3:

[0261] Table 3. Prediction of the effects of various additives

[0262]

[0263] As a barrier layer material for solid oxide fuel cells (SOFCs), the present invention exhibits good performance in various aspects.

[0264] 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 below 10%, which proves the rationality of the element selection of the present invention. The barrier layer material prepared under the element ratio of the present invention has a theoretical basis for being able to serve as a SOFC barrier layer.

[0265] In terms of thermal expansion coefficient, the CTE of the embodiment is between 10-10.5×10 -6 / K, which is almost identical to the selected YSZ electrolyte sheet. The close combination of the two has enabled it to achieve over 50 thermal shock cycles and a power degradation 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.

[0266] In terms of oxygen negative ion conductivity, when the Al molar ratio is 14.5% and the Ce molar ratio is 50% (Example 2), the material exhibits the best ionic conductivity (0.09S / cm) and the lowest electronic conductivity (0.006S / cm). 4+ / Ce 3+ The variable valence characteristics promote 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 presence of high entropy structure makes the diffusion path of oxygen ions in the material more diverse, enhances disordered motion, reduces activation energy, and creates an efficient diffusion barrier, so that the material has high oxygen negative ion conduction efficiency. The ionic conductivity (800℃) is 0.09S / cm and the activation energy is only 0.82eV.

[0267] At the same time, in terms of suppressing Zr element diffusion, 35.5% of rare earth elements significantly reduced the element interdiffusion coefficient to 2×10 -16 cm 2 / s, which is only 27% of that in comparative example 3 without rare earth elements. This multi-element solid solution structure not only hinders element diffusion but also increases the overall configuration entropy of the material, thereby improving the bonding strength to 40MPa.

[0268] Example 2, with a HEO layer thickness of 3 μm and a substrate layer of 12 μm, exhibited the best interface stability, with an interface resistance increase of only 7%, much lower than the control groups with too thin (1 μm) or too thick (10 μm). This thickness combination ensures complete interface coverage while avoiding the increase in ion transport resistance caused by excessive thickness. It is worth noting that when the substrate layer thickness is increased to 40 μm (Comparative Example 8), although the power density remains at 0.87 W / cm 2 However, the number of thermal shock cycles dropped to 38 times, indicating that an overly thick substrate layer would affect long-term stability due to the accumulation of thermal stress.

[0269] In summary, the optimized ratio of Al (14.5%), Ce (50%) and rare earth elements (35.5%), combined with the structural design of a 3μm alloy layer and a 12μm substrate layer, can simultaneously achieve high ionic conductivity (0.09S / cm), low interface degradation (resistance increase <8%) and excellent thermomechanical stability (thermal shock cycles >50 times).

[0270] This barrier layer of YSZ / GDC / HEO layer provides an ideal solution for the long-term stable operation of SOFC through multi-scale composition-structure synergistic design.

[0271] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A method for preparing a barrier layer material for a solid oxide fuel cell, characterized in that: The following steps are involved: S1. Preparation of YSZ / GDC substrate layer S1.

1. Preparation of YSZ substrate green body: Cast the YSZ slurry into a thin film on the electrolyte sheet, and dry it at 60-80°C for 12-24 hours to ensure complete drying to obtain a YSZ matrix layer green body; S1.

2. Preparation of GDC substrate green body: Cast the GDC slurry on the YSZ substrate layer green body into a thin film, and dry it at 60-80℃ for 12-24h to ensure it is completely dry to obtain the GDC substrate layer green body; S1.3, Lamination and Co-sintering: The GDC substrate layer green body, the YSZ substrate layer green body, the electrolyte sheet, and the anode sheet were stacked, vacuum sealed, and isostatically pressed at 70°C and a pressure of 50 MPa for 20 minutes to obtain a composite green body; After sintering the composite green body, a single cell rough body containing a YSZ / GDC matrix layer is formed; S2. Preparation of alloy slurry S2.1, Preprocessing: After pre-treating metals La, Ce, Nd, Gd, Co, Cu and Al, metal powders with a particle size of less than 1 μm are obtained; S2.

2. Preparation of alloy slurry: The metals La, Ce, Nd, Gd, Co, Cu and Al were mixed in a certain molar ratio, polyvinyl butyral and dibutyl phthalate were added, and ball milling was continued for 24 hours under the same conditions. After filtration, vacuum degassing was carried out 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, where 40≤y≤60, 11.5≤z≤17.5, x+y+z=100; S3. Preparation of HEO layer The high entropy alloy (La 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 YSZ / GDC substrate surface of the single cell blank, evenly coated, and then dried at 60°C for 2 hours to obtain the single cell blank. The single cell blanks were sintered twice in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The program settings were as follows: ①Heat from room temperature to 400℃ at a heating rate of 1-2℃ / min and sinter in vacuum; ② Raise the temperature to 800℃ at a heating rate of 3℃ / min, keep warm for 1h, and sinter in vacuum; ③ The temperature was further increased to 1200°C at a heating rate of 2°C / min, kept at this temperature for 4 hours, and then vacuum sintered; ④ The sample is cooled in the furnace in an atmosphere of 7% oxygen and 93% nitrogen, and the cooling rate is controlled at no more than 5°C / min; A single cell containing a high entropy alloy oxide (HEO) layer is obtained.

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

3. The method for preparing a barrier layer material for a solid oxide fuel cell according to claim 1, wherein: The preparation process of the YSZ slurry is as follows: after pre-treating the YSZ powder, anhydrous ethanol and anhydrous triethanolamine are added and mixed and ball-milled for 24 hours to obtain a YSZ composite powder suspension; Polyvinyl butyral and dibutyl phthalate were added to the YSZ composite powder suspension, and the mixture was ball-milled for 24 h. After filtration, vacuum degassing was performed for 30 min to obtain a YSZ slurry. The mass ratio of YSZ powder, starch powder, solvent 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, that is, yttrium-doped zirconia.

4. The method for preparing a barrier layer material for a solid oxide fuel cell according to claim 1, wherein: 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°C for 12-24 hours, and passed through a 200-mesh sieve to obtain a GDC composite powder; After calcining the GDC composite powder, anhydrous ethanol, polyvinyl butyral and dibutyl phthalate were added, and ball milling was continued for 24 hours. After filtration, vacuum degassing was performed for 30 minutes to obtain GDC slurry; The mass ratio of CeO2 powder to 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 barrier layer material for a solid oxide fuel cell according to claim 1, wherein: In S1.3, the specific steps of sintering the composite green body are as follows: The composite green body was spread on an alumina sintering plate and sintered in a HIGH MULTI 5000 / 10000 multifunctional vacuum sintering furnace. The sintering atmosphere was air and the program settings were as follows: ①Heat from room temperature to 600℃ at a heating rate of 2℃ / min and keep warm for 4h; ②Heating from 600℃ to 1000℃ at a rate of 5℃ / min and keeping warm for 1h; ③Heating from 1000℃ to 1400℃ at a rate of 2℃ / min and keeping warm for 4h; ④ When cooling, the cooling rate is ≤5℃ / min, and it is taken out when the temperature is below 200℃; In the matrix layer, the thickness ratio of the YSZ matrix layer green body and the GDC matrix layer green body is 1:1; the thickness of the YSZ / GDC matrix layer prepared by S1 is 8-16 μm.

6. The method for preparing a barrier layer material for a solid oxide fuel cell according to claim 1, characterized in that: The specific process of the S2.1 pretreatment is as follows: After pretreatment, metals La, Ce, Nd, Gd, Co, Cu and Al were placed in the tungsten carbide ball mill of a QM-3SP4 planetary ball mill. Grinding balls were weighed according to a ball-to-material ratio of 15:1 and placed in the ball mill. Anhydrous ethanol and anhydrous triethanolamine were added. Through three vacuum-inflation cycles, the atmosphere is ensured to be high-purity Ar with a final pressure of 0.5 MPa; the suspension is obtained by grinding at a speed of 350 rpm and a ball milling time of 24 hours. The suspension is placed in an ultrasonic tank and ultrasonicated at 40 kHz for 30 minutes, and cooled in a water bath to maintain the temperature <40°C; after the ultrasonication is completed, the suspension is placed in a centrifuge and centrifuged at a speed of 3000 rpm for 10 minutes. The supernatant is placed in a vacuum drying oven and dried at 60°C for 2 hours to obtain a metal powder with a particle size of less than 1 μm.

7. The method for preparing a barrier layer material for a solid oxide fuel cell according to claim 1, characterized in that: The mass ratio of the 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 barrier layer material for a solid oxide fuel cell according to claim 1, characterized in that: The thickness of the high entropy alloy oxide HEO layer prepared in S3 is 2-4 μm.

9. A solid oxide fuel cell barrier layer material prepared by the preparation method according to any one of claims 1 to 8, characterized in that: It includes a YSZ / GDC substrate layer and a high entropy alloy oxide HEO layer.

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