Composite buried burning powder, buried burning method and anode-supported fuel cell electrolyte layer

Abstract

The invention relates to the technical field of solid fuel cell preparation, in particular to composite buried burning powder, a buried burning method and an anode support type fuel cell electrolyte layer, the composite buried burning powder comprises protective layer buried burning powder, compensation layer buried burning powder and volatile layer buried burning powder; the compensation layer buried burning powder is prepared from the following components in percentage by mass: 55 percent to 60 percent of BZCYYb powder and 40 percent to 45 percent of BaCO3 powder; the volatile layer buried burning powder comprises the following components in percentage by weight: 40%-45% of BZCYYb powder and 55%-60% of BaCO3 powder; the protective layer buried burning powder is used for protecting the surface flatness and density of the electrolyte and balancing the interlayer BaO partial pressure; the compensation layer buried powder is used for dynamically compensating the BaO atmosphere; the volatile layer buried burning powder is used for providing saturated BaO vapor concentration. A large amount of low-price BaCO3 powder is adopted in the buried burning powder to replace BZCYYb powder, so that the use cost of the BZCYYb powder can be effectively reduced, gradient regulation and control of BaO steam are realized, and the problems that electrolyte Ba of an existing anode support body half cell volatilizes and the use cost of the BZCYYb buried burning powder is high are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of solid fuel cell preparation, specifically to a composite buried burning powder, a buried burning method and an anode supported fuel cell electrolyte layer, especially to a composite buried burning powder and a buried burning method for a large-sized anode supported fuel cell electrolyte layer. Background Art

[0002] Solid Oxide Fuel Cell (SOFC) is an efficient and clean energy device that directly converts the chemical energy of fuel into electrical energy at high temperature. SOFC consists of an anode, an electrolyte, and a cathode. The commonly used large-size solid oxide fuel cells are mainly flat anode-supported types. SOFC can be divided into two categories according to the different electrolyte conduction carriers: oxygen-ion conducting solid oxide fuel cells (O-SOFC) and proton-conducting solid oxide fuel cells (H-SOFC). The conduction activation barrier of protons is low, only 0.3 to 0.6 eV. H-SOFC, which uses protons as conducting ions, has many advantages in the medium temperature range, such as fast start and stop, low operating cost, and long service life. More and more scholars have begun to study proton-conducting solid oxide fuel cells.

[0003] In the field of proton conductor solid oxide fuel cells, BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ As a proton conductor material, the prepared electrolyte has excellent sintering performance, proton conductivity, and chemical stability. However, similar to other barium-based ceramic materials, BZCYYb electrolyte has Ba volatilization during sintering. This is because the entropy of Ba evaporation is extremely low (142 kJmol at 298 K). -1 ), when the temperature rises above 1400℃, Ba escapes and volatilizes from the lattice in the form of BaO. The loss of Ba at the A position leads to lattice distortion, which not only destroys the stability of the perovskite structure and reduces the density of the electrolyte, but also easily leads to Y 2 O 3 , Yb 2 O 3 The formation of segregation phases significantly reduces the electrolyte proton conductivity and affects battery performance. Therefore, how to balance cost and quality in the process of preparing BZCYYb electrolyte layer has become one of the urgent problems to be solved in the field of large-scale anode-supported fuel cells.

[0004] The traditional buried burning method requires a uniform coating of BZCYYb powder with a thickness of about 0.5-1cm on the electrolyte to ensure a good Ba volatilization inhibition effect. However, in the actual process of electrolyte sintering of large-sized anode support half-cells, the traditional buried burning method requires the use of a large amount of BZCYYb powder, which obviously greatly increases the production cost. If the amount of BZCYYb powder used is reduced, the thickness of the buried burning layer will inevitably be reduced, resulting in poor buried burning effect, and the final average Ba retention rate will be less than 85%; therefore, there is an urgent need for a method that can reduce the use of BZCYYb powder on the basis of improving the Ba retention rate, improve the buried burning quality and reduce the buried burning cost, so as to meet the production needs of large-sized anode support fuel cells. Summary of the invention

[0005] In view of the problems in the prior art that the electrolyte Ba of the anode support half-cell volatilizes and the use cost of BZCYYb buried burning powder is high, the present invention provides a composite buried burning powder, a buried burning method and an anode support fuel cell electrolyte layer.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] The present invention provides a composite buried calcined powder, comprising a protective layer buried calcined powder, a compensation layer buried calcined powder and a volatile layer buried calcined powder; the protective layer buried calcined powder is BZCYYb powder; the compensation layer buried calcined powder comprises 55% to 60% of BZCYYb powder and 40% to 45% of BaCO in terms of mass percentage. 3 The volatile layer buried powder includes 40% to 45% BZCYYb powder and 55% to 60% BaCO 3 pink.

[0008] The present invention also provides a method for burying and burning using the composite burying and burning powder, comprising:

[0009] The protective layer of buried burning powder, the compensation layer of buried burning powder and the volatile layer of buried burning powder are sequentially laid on the electrolyte layer of the anode support type fuel cell to be buried and burned to form a buried and burned system;

[0010] The buried firing system is placed in an air atmosphere system, and gradient sintering is adopted to obtain a finished product of the electrolyte layer of the anode-supported fuel cell, thus completing the buried firing.

[0011] Optionally, before sequentially laying the protective layer burying powder, the compensation layer burying powder and the volatile layer burying powder on the electrolyte layer of the anode supported fuel cell to be buried, the protective layer burying powder, the compensation layer burying powder and the volatile layer burying powder are pre-burned respectively.

[0012] Optionally, the pre-firing temperature is 250° C. to 350° C., and the pre-firing time is 1 to 3 hours.

[0013] Optionally, the particle size of the protection layer embedded powder is 2-5 μm; the particle sizes of the compensation layer embedded powder and the volatile layer embedded powder are both 10-20 μm.

[0014] Optionally, the thickness of the protective layer buried with the fired powder is 1-2 mm, and the compaction density is ≥85%; the thickness of the compensation layer buried with the fired powder is 1.5-2.5 mm; and the thickness of the volatile layer buried with the fired powder is 2-3 mm.

[0015] Optionally, the buried firing system is placed in an air atmosphere system and gradient sintering is performed to obtain a finished product of the anode-supported fuel cell electrolyte layer. The buried firing is completed by:

[0016] The buried firing system is placed in an air atmosphere system, and first gradient sintering, second gradient sintering, third gradient sintering, fourth gradient sintering and cooling are performed in sequence to obtain a finished product of the anode-supported fuel cell electrolyte layer, and the buried firing is completed;

[0017] Among them, the first gradient sintering temperature is 1000℃~1150℃, and the holding time is 30~60min; the second gradient sintering temperature is 1250℃~1350℃, and the holding time is 30~60min; the third gradient sintering temperature is 1400℃~1500℃, and the holding time is 5~7h; the fourth gradient sintering temperature is 1000℃~1150℃, and the holding time is 30~60min.

[0018] Optionally, the first gradient sintering heating rate is 3-4°C / min; the second gradient sintering heating rate is 1-2°C / min; the third gradient sintering heating rate is 0.5-1°C / min; the fourth gradient sintering cooling rate is 1-2°C / min.

[0019] Optionally, the cooling method is:

[0020] After the fourth gradient sintering and heat preservation is completed, the temperature is lowered to 550°C to 600°C at a rate of 3 to 4°C / min, and then cooled to room temperature along with the furnace.

[0021] An anode-supported fuel cell electrolyte layer obtained by embedding and firing using the above embedding and firing method, wherein the retention rate of Ba in the anode-supported fuel cell electrolyte layer reaches 97.1%.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The composite buried powder of the present invention comprises a protective layer buried powder, a compensation layer buried powder and a volatile layer buried powder; wherein the protective layer buried powder is BZCYYb powder, which is used to protect the surface flatness and density of the electrolyte and balance the BaO partial pressure between layers to prevent excessive partial pressure difference; the compensation layer buried powder comprises 55% to 60% of BZCYYb powder and 40% to 45% of BaCO 3 Powder is used to dynamically compensate for BaO atmosphere and stabilize the local BaO partial pressure level; the volatile layer buried powder includes 40% to 45% BZCYYb powder and 55% to 60% BaCO 3 Powder, through excess BaCO 3 Decompose to provide saturated BaO vapor concentration, further ensuring the Ba retention rate of the final product. The buried powder uses a large amount of low-cost BaCO 3 Powder replaces BZCYYb powder, BaCO 3 The buried powder is a highly active Ba source and does not react with BZCYYb. After buried powder, dynamic compensation of BaO vapor is achieved to form a stable local saturated BaO vapor concentration, which inhibits the volatilization of BaO. The BZCYYb powder maintains chemical compatibility to prevent the buried powder from agglomerating at high temperature and adhering to the electrolyte, while slowing down the overall BaO vapor volatilization rate of the buried powder, and maintaining a stable saturated BaO vapor concentration for a long time. Therefore, the present invention forms a stable BaO gradient volatilization structure by using the protective layer buried powder, the compensation layer buried powder and the volatilization layer buried powder, and realizes the BaCO 3 The composite buried fired powder provided by the present invention complements the functional advantages of BZCYYb powder. Compared with traditional buried fired powder, the composite buried fired powder has the characteristics of high Ba retention rate and low cost, which is of great significance for improving the product quality and economic benefits of anode support half-cells, especially large-sized anode support half-cells.

[0024] The present invention also provides a method for burying and firing using the composite burying and firing powder. The method forms a burying and firing system by sequentially laying a protective layer burying and firing powder, a compensation layer burying and firing powder, and a volatile layer burying and firing powder on the electrolyte layer of the anode-supported fuel cell to be buried and fired, and sintering is performed to obtain a finished product of the electrolyte layer of the anode-supported fuel cell, and the burying and firing is completed. The gradient layered burying and firing process is used in conjunction with the protective layer burying and firing powder, the compensation layer burying and firing powder, and the volatile layer burying and firing powder to achieve gradient control of the BaO atmosphere, so that the burying and firing area forms a stable saturated BaO vapor interval as a whole, greatly reducing the driving force for Ba volatilization in the electrolyte, and achieving the effect of inhibiting Ba volatilization. The burying and firing method is simple and easy to operate, and effectively realizes the synergy of the protective layer burying and firing powder, the compensation layer burying and firing powder, and the volatile layer burying and firing powder, which not only protects the surface characteristics of the electrolyte, but also stabilizes the BaO partial pressure level and improves the retention rate of Ba, while reducing the use cost of BZCYYb powder, greatly improving product quality and economic benefits, and providing a new technical approach for the preparation of high-performance electrolyte materials.

[0025] Before sequentially laying the protective layer buried powder, the compensation layer buried powder and the volatile layer buried powder on the electrolyte layer of the anode supported fuel cell to be buried, the protective layer buried powder, the compensation layer buried powder and the volatile layer buried powder are pre-burned respectively. The pre-burning can effectively remove the adsorbed water and improve the activity of the buried powder, so that the components in the buried powder are more evenly distributed, avoiding the phenomenon of local component segregation or enrichment during the sintering process, thereby helping to improve the performance of the electrolyte layer.

[0026] The present invention also provides an anode-supported fuel cell electrolyte layer prepared by the above-mentioned buried firing method. After testing, the retention rate of Ba in the anode-supported fuel cell electrolyte layer reached 97.1%, and the cost was reduced by 55%. It has better product quality, lower cost, and greater market competitiveness. It provides new ideas and methods for the sustainable development of fuel cell technology, helps to promote the commercial application of fuel cell technology, and contributes to energy transformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a process flow of a buried burning method of the present invention.

[0028] Figure 2 This is a structural diagram of the buried burning system in the buried burning method of the present invention.

[0029] Figure 3 This is a surface structure diagram of the finished product of the anode-supported fuel cell electrolyte layer prepared in Example 1 of the present invention.

[0030] Figure 4 This is a surface SEM image of the finished product of the anode-supported fuel cell electrolyte layer prepared in Example 1 of the present invention.

[0031] Figure 5 This is a surface SEM image of the finished product of the anode-supported fuel cell electrolyte layer prepared in Comparative Example 1 of the present invention.

[0032] Figure 6 This is a surface SEM image of the finished product of the anode-supported fuel cell electrolyte layer prepared in Comparative Example 2 of the present invention.

[0033] Figure 7 This is a comparison chart of the Ba retention rate test results and cost calculation of the finished anode-supported fuel cell electrolyte layer prepared in Example 1, Comparative Example 1 and Comparative Example 2 of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0035] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0036] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0037] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0038] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0039] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0040] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0041] The present invention is further described in detail below in conjunction with specific embodiments, which are intended to explain the present invention rather than to limit it.

[0042] The invention discloses a composite buried powder, comprising a protective layer buried powder, a compensation layer buried powder and a volatile layer buried powder; the protective layer buried powder is BZCYYb powder; the compensation layer buried powder comprises 55% to 60% of BZCYYb powder and 40% to 45% of BaCO in terms of mass percentage. 3 The volatile layer buried powder includes 40% to 45% BZCYYb powder and 55% to 60% BaCO 3 The protective layer buried powder is used to protect the surface flatness and density of the electrolyte, and balance the BaO partial pressure between layers to prevent excessive partial pressure difference; the compensation layer buried powder is used to dynamically compensate for the BaO atmosphere and stabilize the local BaO partial pressure level, thereby ensuring the Ba retention rate of the final product; the volatile layer buried powder is used to pass the excess BaCO 3 Decomposition strengthens atmosphere control, provides sufficient BaO vapor concentration, and further ensures the Ba retention rate of the final product. Through the synergistic effect of the three types of buried burning powders, not only the surface characteristics of the electrolyte are protected, but also the BaO partial pressure level is stabilized, the Ba retention rate is increased, the product quality is improved, and the buried burning cost is greatly reduced, which has better applicability and economy.

[0043] See also Figure 1 The present invention provides a method for burying and burning the composite burying and burning powder, comprising:

[0044] S1: sequentially laying a protective layer of buried burning powder, a compensation layer of buried burning powder and a volatile layer of buried burning powder on the electrolyte layer of the anode supported fuel cell to be buried and burned to form a buried and burned system, specifically:

[0045] See also Figure 2The buried burning system includes a large-sized anode support fuel cell structure composed of a BZCYYB electrolyte layer and an anode support, and a protective layer buried burning powder, a compensation layer buried burning powder and a volatile layer buried burning powder are sequentially laid on the electrolyte layer of the large-sized anode support fuel cell structure;

[0046] The protective layer buried powder, compensation layer buried powder and volatile layer buried powder are respectively configured in proportion, and are respectively subjected to spheroidal graphite treatment and pre-fired respectively; wherein the ball milling speed of the protective layer buried powder is controlled at 200-400r / min, the ball milling time can be but not limited to 24h, and the average particle size of the buried powder obtained is 2-5μm; the ball milling speed of the compensation layer buried powder and the volatile layer buried powder is controlled at 100-200r / min, the ball milling time can be but not limited to 24h, and the average particle size of the buried powder obtained is 10-20μm; when laying, the buried powder of the protective layer is laid with a thickness of 1-2mm and a compaction density of ≥85%; the buried powder of the compensation layer is laid with a thickness of 1.5-2.5mm and is loosely stacked; the buried powder of the volatile layer is laid with a thickness of 2-3mm and is lightly pressed to be naturally dense; the pre-fired temperature of the three buried powders is 250℃-350℃, and the pre-fired time is 1-3h.

[0047] S2: placing the buried firing system in an air atmosphere system and adopting gradient sintering to obtain a finished product of the anode-supported fuel cell electrolyte layer and complete the buried firing, specifically:

[0048] The buried firing system is placed in an air atmosphere system, and first gradient sintering, second gradient sintering, third gradient sintering, fourth gradient sintering and cooling are performed in sequence to obtain a finished product of the anode-supported fuel cell electrolyte layer, and the buried firing is completed;

[0049] Among them, the first gradient sintering temperature is 1000℃~1150℃, the holding time is 30~60min, and the heating rate is 3~4℃ / min; the second gradient sintering temperature is 1250℃~1350℃, the holding time is 30~60min, and the heating rate is 1~2℃ / min; the third gradient sintering temperature is 1400℃~1500℃, the holding time is 5~7h, and the heating rate is 0.5~1℃ / min; the fourth gradient sintering temperature is 1000℃~1150℃, the holding time is 30~60min, and the cooling rate is 1~2℃ / min; after the fourth gradient sintering and insulation is completed, the temperature is reduced to 550℃~600℃ at 3~4℃ / min, and then cooled to room temperature with the furnace to obtain the anode supported fuel cell electrolyte layer finished product, and the buried firing is completed.

[0050] Example 1

[0051] The size of the anode-supported fuel cell used in this example is 5cm*5cm*0.5mm (length*width*height);

[0052] The ball milling speed was controlled at 300 r / min to mill BZCYYb powder, and the average particle size of the powder was 2-5 μm to obtain the protective layer buried powder; BZCYYb powder was mixed with BaCO 3 The powders were mixed in a mass ratio of 6:4, and the ball milling speed was controlled at 150r / min. The powders were ball milled to an average particle size of 10-20μm to obtain compensation layer buried powder. 3 The powders were mixed in a mass ratio of 4:6, the ball milling speed was controlled at 150 r / min, and the powders were ball milled to an average particle size of 10-20 μm to obtain volatile layer buried powder. The three powders were pre-calcined at 300 °C for 2 h.

[0053] Place a large-sized anode support body half-cell blank on the supporting plate, and evenly cover the top of the electrolyte layer with a protective layer of buried powder with a thickness of 1mm and a compaction density ≥85%; then evenly cover the protective layer of buried powder with a compensation layer of buried powder with a thickness of 1.5mm and loosely stack it; finally, evenly cover the compensation layer of buried powder with a volatile layer of buried powder with a thickness of 2.5mm, and lightly press it until it is naturally dense to form a buried system.

[0054] High-temperature sintering under air, heating the buried sintering system to 1100°C at a heating rate of 4°C / min, keeping warm for 45 minutes to complete the first gradient sintering; heating to 1300°C at a heating rate of 2°C / min, keeping warm for 45 minutes to complete the second gradient sintering; heating to 1400°C at a heating rate of 0.5°C / min, keeping warm for 7 hours to complete the third gradient sintering; cooling to 1100°C at a cooling rate of 1°C / min, keeping warm for 45 minutes to complete the fourth gradient sintering; finally cooling to 600°C at a cooling rate of 4°C / min, and finally cooling to room temperature with the furnace to obtain the finished anode-supported fuel cell electrolyte layer.

[0055] Example 2

[0056] The size of the anode-supported fuel cell used in this example is 5cm*5cm*0.5mm (length*width*height);

[0057] The ball milling speed was controlled at 400 r / min to mill BZCYYb powder, and the average particle size of the powder was 2-5 μm to obtain protective layer buried powder; BZCYYb powder was mixed with BaCO 3 The powders were mixed in a mass ratio of 5.5:4.5, and the ball milling speed was controlled at 200r / min. The powders were ball milled to an average particle size of 10-20μm to obtain compensation layer buried powder. 3 The powders were mixed in a mass ratio of 4.5:5.5, the ball milling speed was controlled at 200 r / min, and the powders were ball milled to an average particle size of 10-20 μm to obtain volatile layer buried powder. The three powders were pre-calcined at 250° C. for 3 h.

[0058] Place a large-sized anode support body half-cell blank on the supporting plate, and evenly cover the top of the electrolyte layer with a protective layer of buried powder with a thickness of 1mm and a compaction density ≥85%; then evenly cover the protective layer of buried powder with a compensation layer of buried powder with a thickness of 1.5mm and loosely stack it; finally, evenly cover the compensation layer of buried powder with a volatile layer of buried powder with a thickness of 2.5mm, and lightly press it until it is naturally dense to form a buried system.

[0059] High-temperature sintering under air, heating the buried sintering system to 1000°C at a heating rate of 3°C / min, keeping it warm for 60 minutes to complete the first gradient sintering; heating it to 1350°C at a heating rate of 1°C / min, keeping it warm for 30 minutes to complete the second gradient sintering; heating it to 1500°C at a heating rate of 1°C / min, keeping it warm for 5 hours to complete the third gradient sintering; cooling it to 1000°C at a cooling rate of 2°C / min, keeping it warm for 50 minutes to complete the fourth gradient sintering; finally cooling it to 600°C at a cooling rate of 3°C / min, and finally cooling it to room temperature with the furnace to obtain a finished anode-supported fuel cell electrolyte layer.

[0060] Example 3

[0061] The size of the anode-supported fuel cell used in this example is 5cm*5cm*0.5mm (length*width*height);

[0062] The ball milling speed was controlled at 200 r / min to mill BZCYYb powder, and the average particle size of the powder was 2-5 μm to obtain protective layer buried powder; BZCYYb powder was mixed with BaCO 3 The powders were mixed in a mass ratio of 5.7:4.3, and the ball milling speed was controlled at 100r / min. The powders were ball milled to an average particle size of 10-20μm to obtain compensation layer buried powder. 3 The powders were mixed in a mass ratio of 4.3:5.7, the ball milling speed was controlled at 150 r / min, and the powders were ball milled to an average particle size of 10-20 μm to obtain volatile layer buried powder. The three powders were pre-calcined at 350 °C for 1 h.

[0063] Place a large-sized anode support body half-cell blank on the supporting plate, and evenly cover the top of the electrolyte layer with a protective layer of buried powder with a thickness of 2mm and a compaction density ≥85%; then evenly cover the protective layer of buried powder with a compensation layer of buried powder with a thickness of 2mm and loosely stack it; finally, evenly cover the compensation layer of buried powder with a volatile layer of buried powder with a thickness of 2mm, and lightly press it until it is naturally dense to form a buried system.

[0064] High-temperature sintering under air, heating the buried-firing system to 1100°C at a heating rate of 3.5°C / min, keeping it warm for 50 minutes to complete the first gradient sintering; heating it to 1300°C at a heating rate of 1.5°C / min, keeping it warm for 40 minutes to complete the second gradient sintering; heating it to 1450°C at a heating rate of 0.8°C / min, keeping it warm for 6 hours to complete the third gradient sintering; cooling it to 1000°C at a cooling rate of 2°C / min, keeping it warm for 50 minutes to complete the fourth gradient sintering; finally cooling it to 600°C at a cooling rate of 3°C / min, and finally cooling it to room temperature with the furnace to obtain a finished anode-supported fuel cell electrolyte layer.

[0065] Example 4

[0066] The size of the anode-supported fuel cell used in this example is 5cm*5cm*0.5mm (length*width*height);

[0067] The ball milling speed was controlled at 350 r / min to mill BZCYYb powder, and the average particle size of the powder was 2-5 μm to obtain protective layer buried powder; BZCYYb powder and BaCO 3 The powders were mixed in a mass ratio of 5.9:4.1, and the ball milling speed was controlled at 200r / min. The powders were ball milled to an average particle size of 10-20μm to obtain compensation layer buried powder. 3 The powders were mixed in a mass ratio of 4.1:5.9, the ball milling speed was controlled at 150 r / min, and the powders were ball milled to an average particle size of 10-20 μm to obtain volatile layer buried powder. The three powders were pre-calcined at 300 °C for 2 h.

[0068] Place a large-sized anode support body half-cell blank on the supporting plate, and evenly cover the top of the electrolyte layer with a protective layer of buried powder with a thickness of 2mm and a compaction density ≥85%; then evenly cover the protective layer of buried powder with a compensation layer of buried powder with a thickness of 2.5mm and loosely stacked; finally, evenly cover the compensation layer of buried powder with a volatile layer of buried powder with a thickness of 3mm, and lightly press until it is naturally dense to form a buried system.

[0069] High-temperature sintering under air, heating the buried-firing system to 1150°C at a heating rate of 4°C / min, keeping it warm for 60 minutes to complete the first gradient sintering; heating it to 1250°C at a heating rate of 1°C / min, keeping it warm for 30 minutes to complete the second gradient sintering; heating it to 1450°C at a heating rate of 1°C / min, keeping it warm for 6 hours to complete the third gradient sintering; cooling it to 1000°C at a cooling rate of 2°C / min, keeping it warm for 30 minutes to complete the fourth gradient sintering; finally cooling it to 600°C at a cooling rate of 3°C / min, and finally cooling it to room temperature with the furnace to obtain a finished anode-supported fuel cell electrolyte layer.

[0070] Example 5

[0071] The size of the anode-supported fuel cell used in this example is 5cm*5cm*0.5mm (length*width*height);

[0072] The ball milling speed was controlled at 400 r / min to mill BZCYYb powder, and the average particle size of the powder was 2-5 μm to obtain protective layer buried powder; BZCYYb powder was mixed with BaCO 3 The powders were mixed in a mass ratio of 5.6:4.4, and the ball milling speed was controlled at 200r / min. The powders were ball milled to an average particle size of 10-20μm to obtain compensation layer buried powder. 3 The powders were mixed in a mass ratio of 4.4:5.6, the ball milling speed was controlled at 200 r / min, and the powders were ball milled to an average particle size of 10-20 μm to obtain volatile layer buried powder. The three powders were pre-calcined at 300 °C for 3 h.

[0073] Place a large-sized anode support body half-cell blank on the supporting plate, and evenly cover the top of the electrolyte layer with a protective layer of buried powder with a thickness of 1.5mm and a compaction density ≥85%; then evenly cover the protective layer of buried powder with a compensation layer of buried powder with a thickness of 2mm and loosely stack it; finally, evenly cover the compensation layer of buried powder with a volatile layer of buried powder with a thickness of 2mm, and lightly press it until it is naturally dense to form a buried system.

[0074] High-temperature sintering under air, heating the buried-firing system to 1100°C at a heating rate of 4°C / min, keeping warm for 35 minutes to complete the first gradient sintering; heating to 1400°C at a heating rate of 1°C / min, keeping warm for 40 minutes to complete the second gradient sintering; heating to 1480°C at a heating rate of 1°C / min, keeping warm for 5 hours to complete the third gradient sintering; cooling to 1100°C at a cooling rate of 2°C / min, keeping warm for 45 minutes to complete the fourth gradient sintering; finally cooling to 600°C at a cooling rate of 3°C / min, and finally cooling to room temperature with the furnace to obtain a finished anode-supported fuel cell electrolyte layer.

[0075] Comparative Example 1

[0076] The size of the anode-supported fuel cell used is 5cm*5cm*0.5mm (length*width*height);

[0077] The ball mill speed is controlled at 300 r / min to ball mill BZCYYb powder, and the average powder particle size is 2-5 μm to obtain BZCYYb buried calcined powder; the BZCYYb buried calcined powder is pre-calcined at 300° C. for 2 h.

[0078] A large-sized anode support half-cell blank is placed on the support plate, and BZCYYb buried powder is evenly covered on the top of the electrolyte layer with a thickness of 5 mm.

[0079] High-temperature sintering under air, heating the buried sintering system to 1100°C at a heating rate of 4°C / min, keeping warm for 45 minutes to complete the first gradient sintering; heating to 1300°C at a heating rate of 2°C / min, keeping warm for 45 minutes to complete the second gradient sintering; heating to 1400°C at a heating rate of 0.5°C / min, keeping warm for 7 hours to complete the third gradient sintering; cooling to 1100°C at a cooling rate of 1°C / min, keeping warm for 45 minutes to complete the fourth gradient sintering; finally cooling to 600°C at a cooling rate of 4°C / min, and finally cooling to room temperature with the furnace to obtain the finished anode-supported fuel cell electrolyte layer.

[0080] Comparative Example 2

[0081] The size of the anode-supported fuel cell used is 5cm*5cm*0.5mm (length*width*height);

[0082] The ball milling speed is controlled at 300 r / min to ball mill BZCYYb powder, and the average powder particle size is 2-5 μm to obtain BZCYYb buried calcined powder; the BZCYYb buried calcined powder is pre-calcined at 300° C. for 2 h.

[0083] A large-sized anode support half-cell blank is placed on the support plate, and BZCYYb buried powder is evenly covered on the top of the electrolyte layer with a thickness of 3 mm.

[0084] High-temperature sintering under air, heating the buried sintering system to 1100°C at a heating rate of 4°C / min, keeping warm for 45 minutes to complete the first gradient sintering; heating to 1300°C at a heating rate of 2°C / min, keeping warm for 45 minutes to complete the second gradient sintering; heating to 1400°C at a heating rate of 0.5°C / min, keeping warm for 7 hours to complete the third gradient sintering; cooling to 1100°C at a cooling rate of 1°C / min, keeping warm for 45 minutes to complete the fourth gradient sintering; finally cooling to 600°C at a cooling rate of 4°C / min, and finally cooling to room temperature with the furnace to obtain the finished anode-supported fuel cell electrolyte layer.

[0085] See also Figure 3 From the surface structure diagram of the finished anode-supported fuel cell electrolyte layer prepared in Example 1, it can be seen that the surface color of the finished anode-supported fuel cell electrolyte layer is uniform, and there is no color spot phenomenon caused by Ba volatilization. After testing, its surface density is >80%.

[0086] See also Figures 4 to 6By comparing the SEM images of the finished anode-supported fuel cell electrolyte layer prepared in Example 1, Comparative Example 1 and Comparative Example 2, it is found that the finished anode-supported fuel cell electrolyte layer prepared in Example 1 and Comparative Example 1 has good grain growth, close adhesion between average grains, no pores, good density, and better performance. However, the finished anode-supported fuel cell electrolyte layer prepared in Comparative Example 2 has a small number of tiny pores on its surface, and the degree of bonding between particles is low, with a density of less than 70%, which may be due to lattice distortion caused by excessive Ba escape.

[0087] To further illustrate the beneficial effects of the present invention, the Ba retention rates of Example 1, Comparative Example 1 and Comparative Example 2 of the present invention were measured, and the cost of burial burning was calculated according to the corresponding amount. The results are shown in Figure 7 It can be seen that the finished anode-supported fuel cell electrolyte layer prepared in Example 1 of the present application has a higher Ba retention rate, and the cost is greatly improved compared with Comparative Examples 1 and 2. Although Comparative Example 1 achieves an improvement in Ba retention rate compared with Comparative Example 2 due to the sufficiently thick BZCYYb powder, its cost is increased by 60% compared with Example 1 of the present invention.

[0088] It can be seen that the finished product treated with the buried-burned powder and the buried-burned method provided by the present invention has a higher Ba retention rate, lower cost and better finished product quality.

[0089] The present invention also provides an anode-supported fuel cell electrolyte layer obtained by burying using the above-mentioned burying method. After testing, the retention rate of Ba in the anode-supported fuel cell electrolyte layer reached 97.1%, and the cost was reduced by 55%. It has better product quality, lower cost, and greater market competitiveness, and provides new ideas and methods for the sustainable development of fuel cell technology, which helps to promote the commercial application of fuel cell technology and contribute to energy transformation.

[0090] In summary, the present invention provides a composite buried burning powder, a buried burning method and an anode supported fuel cell electrolyte layer. By uniformly covering the electrolyte layer with a protective layer buried burning powder, a compensation layer buried burning powder and a volatile layer buried burning powder, combined with gradient sintering, gradient control of the BaO atmosphere is achieved, so that a stable saturated BaO vapor range is formed in the buried burning area as a whole, and the driving force for Ba volatilization in the electrolyte is greatly reduced, which not only achieves the effect of inhibiting Ba volatilization, but also greatly reduces the buried burning cost, and greatly improves product quality and economic benefits.

[0091] The above description is only a preferred embodiment of the present invention and is not intended to impose any limitation on the technical solution of the present invention. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can also be subjected to several simple modifications and substitutions, and these modifications and substitutions are also within the scope of protection covered by the claims.

Claims

1. A composite buried burning powder, characterized in that: It includes a protective layer buried powder, a compensation layer buried powder and a volatile layer buried powder; the protective layer buried powder is BZCYYb powder; the compensation layer buried powder includes 55% to 60% of BZCYYb powder and 40% to 45% of BaCO3 powder by mass percentage; The volatile layer buried powder comprises 40% to 45% of BZCYYb powder and 55% to 60% of BaCO3 powder.

2. The method for burying and burning the composite burying and burning powder according to claim 1, characterized in that: include: The protective layer of buried burning powder, the compensation layer of buried burning powder and the volatile layer of buried burning powder are sequentially laid on the electrolyte layer of the anode support type fuel cell to be buried and burned to form a buried and burned system; The buried firing system is placed in an air atmosphere system, and gradient sintering is adopted to obtain a finished product of the electrolyte layer of the anode-supported fuel cell, thus completing the buried firing.

3. The buried burning method according to claim 2, characterized in that: Before sequentially laying the protective layer burying powder, the compensation layer burying powder and the volatile layer burying powder on the electrolyte layer of the anode supported fuel cell to be buried, the protective layer burying powder, the compensation layer burying powder and the volatile layer burying powder are pre-burned respectively.

4. The buried burning method according to claim 3, characterized in that: The pre-firing temperature is 250° C. to 350° C., and the pre-firing time is 1 to 3 hours.

5. The buried burning method according to claim 2, characterized in that: The particle size of the protection layer buried powder is 2-5 μm; the particle sizes of the compensation layer buried powder and the volatile layer buried powder are both 10-20 μm.

6. The buried burning method according to claim 2, characterized in that: The thickness of the protective layer buried with the fired powder is 1-2 mm, and the compaction density is ≥85%; the thickness of the compensation layer buried with the fired powder is 1.5-2.5 mm; the thickness of the volatile layer buried with the fired powder is 2-3 mm.

7. The buried burning method according to claim 2, characterized in that: The method of placing the buried sintering system in an air atmosphere system and adopting gradient sintering to obtain a finished product of the electrolyte layer of the anode-supported fuel cell is as follows: The buried firing system is placed in an air atmosphere system, and first gradient sintering, second gradient sintering, third gradient sintering, fourth gradient sintering and cooling are performed in sequence to obtain a finished product of the anode-supported fuel cell electrolyte layer, and the buried firing is completed; Among them, the first gradient sintering temperature is 1000℃~1150℃, and the holding time is 30~60min; the second gradient sintering temperature is 1250℃~1350℃, and the holding time is 30~60min; the third gradient sintering temperature is 1400℃~1500℃, and the holding time is 5~7h; the fourth gradient sintering temperature is 1000℃~1150℃, and the holding time is 30~60min.

8. The buried burning method according to claim 7, characterized in that: The heating rate of the first gradient sintering is 3-4°C / min; the heating rate of the second gradient sintering is 1-2°C / min; the heating rate of the third gradient sintering is 0.5-1°C / min; and the cooling rate of the fourth gradient sintering is 1-2°C / min.

9. The buried burning method according to claim 7, characterized in that: The cooling method is: After the fourth gradient sintering and heat preservation is completed, the temperature is lowered to 550°C to 600°C at a rate of 3 to 4°C / min, and then cooled to room temperature along with the furnace.

10. An anode-supported fuel cell electrolyte layer obtained by burying and firing using the burying and firing method according to any one of claims 2 to 9, characterized in that: The retention rate of Ba in the electrolyte layer of the anode supported fuel cell reaches 97.1%.

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