Cathode for protonic solid oxide fuel cell, cell and method for its preparation

Abstract

The application provides a kind of proton type solid oxide fuel cell cathode, cell and its preparation method, belong to fuel cell field, and fuel cell cathode selects YCBCo as cathode catalytic material.YCBCo in 200 DEG C-400 DEG C low temperature interval absorption / desorption oxygen performance meets the requirements of proton type solid oxide fuel cell cathode, and electronic conductivity is 70±10 Scm ‑1 around 600 DEG C.YCBCo material thermal expansion coefficient is about 9.20×10 ‑6 K ‑1 The application provides three kinds of preparation above proton type solid oxide fuel cell cathode method, can obtain single-phase porous YCBCo structure, YCBCo nanoparticle dispersed distribution in BZCY / BCY skeleton structure and YCBCo nanometer film dense coating BZCY / BCY porous skeleton core-shell structure respectively.Cathode catalyst material and skeleton interface are compatible well, and skeleton and electrolyte are combined firmly, and the cathode can finally realize high-performance long-term stable operation of H-SOFC.

Description

Technical Field

[0001] This invention belongs to the field of proton-type solid oxide fuel cells, and more specifically, relates to a proton-type solid oxide fuel cell Y. 1-x Ce x BaCo4O 7+δ Cathode, battery and its preparation method. Background Technology

[0002] To build a sustainable, resource-saving, and ecologically-protective society, the scientific integration and efficient utilization of existing rare earth and hydrocarbon resources will effectively alleviate environmental pollution and energy shortages. Therefore, developing and vigorously promoting the renewable energy industry is of great significance.

[0003] Solid oxide fuel cells (SOFCs) are energy conversion devices with great commercial potential based on hydrogen / hydrocarbon fuels. They have significant advantages such as quiet operation, high efficiency, and stability. Their all-solid-state structure can easily meet the physical requirements of mechanical design, manufacturing, and automation design, which helps to realize the construction of highly integrated small and medium-sized power plants and grid connection of large power plants. Therefore, they have received widespread attention and in-depth research worldwide.

[0004] Traditional oxygen-ion conductive SOFC (O-SOFC) single cells have a three-layer structure. Oxygen is catalytically reduced to oxygen ions via a porous cathode and then directionally conducted to a dense oxygen-ion conductor electrolyte. The oxygen ions then pass through the electrolyte layer and finally reach the porous anode to react with fuel gas to generate H₂O / H₂O + CO₂, which then powers an external load. Due to the high activation energy of oxygen ion conduction, the operating temperature of traditional O-SOFCs is typically in the medium to high temperature range (600℃-1000℃). To reduce operating and maintenance costs and ensure greater structural stability, researchers have focused on lowering the operating temperature from the medium to high temperature range to the low temperature range. However, in the low temperature range (300℃-500℃), the catalytic conversion efficiency and output power of O-SOFCs are insufficient to meet the performance requirements of practical applications. Therefore, attention has turned to low-temperature proton-conducting SOFCs (H-SOFCs). Unlike O-SOFCs, in the H-SOFC system, H₂ is oxidized to H₂ at the porous anode. + It is then directionally conducted through the dense electrolyte layer to the porous cathode, where it reacts with the oxidized and reduced O. 2- The reaction generates H2O on the cathode side, which brings the following advantages: 1. Avoids excessive oxidation of Ni and catalytic deactivation caused by excessive humidity on the anode side; 2. Lower internal resistance of the proton conductor electrolyte and lower ohmic loss of the battery; 3. The generation of H2O on the cathode side can moderately dilute the reaction gas O2 to improve the safety of battery operation.

[0005] Although industry professionals are making great efforts to advance the research progress of H-SOFC in order to realize its large-scale commercial application as soon as possible, H-SOFC technology is still constrained by some technical problems: the widely used Co-based cathode catalysts have excellent performance, but their excessively high thermal expansion coefficient (TEC) is not compatible with general proton conductor electrolytes. Even after high-temperature heat treatment, the binding force between the cathode and the electrolyte is still very weak, and the overall mechanical strength of the battery is insufficient to meet the structural stability requirements of long-term operation; while non-Co-based cathode catalysts have lower conductivity and oxygen reduction reaction (ORR) catalytic activity, which is particularly evident in the low-temperature range.

[0006] Therefore, it is necessary to balance the catalytic activity of the cathode material with the overall structural stability requirements of the battery, and to develop a novel proton-type solid oxide fuel cell cathode catalyst. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a proton-type solid oxide fuel cell Y. 1- x Ce x BaCo4O 7+δ The present invention relates to a cathode, a battery, and a method for preparing the same cathode. By selecting novel materials as cathode catalysts, a good balance is struck between the catalytic activity of the cathode materials and the overall structural stability of the battery. The present invention also provides a method for preparing the cathode, which is simple and easy to implement in engineering.

[0008] To achieve the above objectives, the present invention provides a proton-type solid oxide fuel cell cathode, which uses Y-type protons. 1- x Ce x BaCo4O 7+δ As a cathode catalytic material, Y 1-x Ce x BaCo4O 7+δ It is abbreviated as YCBCo, where 0≤x<1 and 0≤δ<1.

[0009] Furthermore, YCBCo meets the requirements for proton-type solid oxide fuel cell cathodes in the low-temperature range of 200℃ to 400℃ for oxygen absorption / desorption performance, and exhibits an electronic conductivity of 70±10 Scm in the range of 600℃±100℃. -1 The coefficient of thermal expansion of YCBCo material is (9.20±1.00)×10⁻⁶. -6 K -1 .

[0010] According to a second aspect of the present invention, a fuel cell with a proton-type solid oxide fuel cell cathode as described above is also provided.

[0011] According to a third aspect of the present invention, a method for obtaining a proton-type solid oxide fuel cell cathode as described above is also provided, comprising the following steps:

[0012] S1: Dissolve the nitrates of Y, Ba, Ce, and Co in deionized water, respectively. Use glycine as a combustion aid and calcine at 950℃~1000℃ for 3h~5h to obtain black YCBCo powder.

[0013] S2: Grind the black YCBCo powder and binder thoroughly and evenly into a cathode paste, print it onto the electrolyte surface, and calcine it in air at 1000℃~1100℃ for 1.5h~2.5h to obtain a single-phase porous YCBCo cathode.

[0014] According to a fourth aspect of the present invention, a method for obtaining a proton-type solid oxide fuel cell cathode as described above is also provided, comprising the following steps:

[0015] S1: Will Ba 1-x Zr x Ce 1-y Y y O 3-δ Electrolyte and binder are thoroughly and uniformly ground into a skeleton slurry, which is then screen-printed onto the electrolyte surface. The slurry is then calcined in air at 1000℃~1100℃ for 1.5h~2.5h to obtain a porous BZCY skeleton, wherein Ba... 1-x Zr x Ce 1-y Y y O 3-δ Abbreviated as BZCY, where 0 < x < 1, 0 < y < 1.

[0016] S2: Dissolve the nitrates of Y, Ba, Ce, and Co in isopropanol to obtain a first solution. Dissolve glycine and polyvinylpyrrolidone in deionized water to obtain a second solution. Add the second solution dropwise to the first solution to obtain a clear and transparent YCBCo impregnation precursor solution.

[0017] S3: First, the YCBCo impregnation precursor solution is injected into the porous BZCY framework. Then, it is treated under negative pressure for 0.5-1.0 h, followed by calcination at 950-1050℃ for 3-5 h in air to obtain a YCBCo-BZCY composite porous cathode. In this cathode, YCBCo is in the form of nanoparticles, uniformly dispersed on the BZCY framework. In this step, the morphology of the final product can be controlled by adjusting the concentration of the YCBCo impregnation precursor solution. A higher concentration yields a BZCY@YCBCo core-shell structure cathode, with YCBCo forming a thin film coating the surface of the BZCY framework. A lower concentration yields a discretely distributed YCBCo-BZCY composite porous cathode, with YCBCo particles distributed on the surface of the BZCY framework. Whether the YCBCo product is in particulate or film form depends on the concentration of the YCBCo impregnation precursor solution. When the concentration of the YCBCo impregnation precursor solution is less than the critical concentration, YCBCo particles are obtained; when the concentration of the YCBCo impregnation precursor solution is greater than the critical concentration, YCBCo in film form is obtained. The critical concentration is a value between 0.05 mol / L and 0.1 mol / L, and the specific critical value will fluctuate within the range of 0.05 mol / L to 0.1 mol / L depending on the actual engineering conditions and reaction conditions.

[0018] When the concentration of the YCBCo impregnation precursor solution is below 0.05 mol / L, a YCBCo-BZCY composite porous cathode is obtained. In this cathode, the YCBCo is in the form of nanoparticles, uniformly dispersed on the BZCY framework. When the concentration of the YCBCo impregnation precursor solution is between 0.05 mol / L and 0.1 mol / L, a BZCY@YCBCo core-shell structure cathode or a YCBCo-BZCY composite porous cathode may be obtained. When the concentration of the YCBCo impregnation precursor solution is greater than 0.1 mol / L, in the BZCY@YCBCo core-shell structure cathode, YCBCo is coated on the surface of the BZCY framework in a thin film.

[0019] Furthermore, when preparing the second solution, the amount of glycine added is 1.2 to 1.4 times the amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 4% to 6% of the total mass of the first solution and glycine.

[0020] Furthermore, in step S3, the YCBCo nanoparticles in the YCBCo-BZCY composite porous cathode have a particle size range of 20 nm to 100 nm.

[0021] According to a fifth aspect of the present invention, a method for obtaining a proton-type solid oxide fuel cell cathode as described above is also provided, comprising the following steps:

[0022] S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and binder are thoroughly and uniformly ground into a framework slurry, which is then screen-printed onto the electrolyte surface. The slurry is calcined in air at 1000℃~1100℃ for 1h~3h to obtain a porous BCY framework, in which BaCe... 0.8 Y 0.2 O 3-δ Abbreviated as BCY, 0 < δ < 1,

[0023] S2: Co(NO3)2 is dissolved in isopropanol to obtain a Co(NO3)2 solution. The Co(NO3)2 solution is injected into a porous BCY framework and treated under negative pressure. Then, it is calcined in air at 950℃~1050℃ for 3h~5h. Co(NO3)2 reacts in situ with BCY to generate the YCBCo phase. The microstructure of the electrode is controlled by the concentration of the Co(NO3)2 solution. Low concentration Co(NO3)2 solution induces the formation of YCBCo nanoparticles on the surface and / or within the BCY framework, forming an in-situ self-assembled YCBCo-BZCY composite cathode. High concentration Co(NO3)2 solution induces the formation of a continuous YCBCo nanofilm, which densely coats the porous BCY framework to obtain a BCY@YCBCo core-shell structure cathode.

[0024] In step S2, the microstructure of the YCBCo-BCY composite cathode is controlled by the concentration of Co(NO3)2 solution. Co(NO3)2 solution with a concentration below the critical concentration can induce the formation of YCBCo nanoparticles, which are located on the surface and / or within the BCY framework, forming an in-situ self-assembled YCBCo-BCY composite cathode. Co(NO3)2 solution with a concentration above the critical concentration can induce the formation of a continuous YCBCo nanofilm, which densely coats the porous BCY framework, thus obtaining a BCY@YCBCo core-shell structure cathode. The critical concentration is in the range of 0.05 ml / L to 0.1 mol / L.

[0025] Furthermore, the binder comprises the following components and their respective mass percentages: 4 wt.% ethyl cellulose and 96 wt.% terpineol.

[0026] In summary, the technical solutions conceived by this invention have the following beneficial effects compared with the prior art:

[0027] In this invention, YCBCo is selected as the cathode catalyst material, i.e., it is used as the cathode. YCBCo material exhibits excellent O2 adsorption / desorption performance in the low-temperature range of 200℃ to 400℃, meeting the requirements of proton-type solid oxide fuel cell cathodes. Simultaneously, as a Co-based material, YCBCo possesses sufficiently excellent electronic conductivity, with an electronic conductivity of 70±10 Scm in the range of 600℃±100℃. -1 The coefficient of thermal expansion of YCBCo material is well matched with that of commonly used electrolyte materials such as BZCY. The coefficient of thermal expansion of YCBCo material is (9.20±1.00)×10. -6 K -1 It possesses excellent physical compatibility with electrolyte materials. Using YCBCo material as the cathode in H-SOFCs can achieve excellent interfacial bonding with electrolyte materials while meeting catalytic activity requirements, thereby ensuring the battery's output power and long-term operational stability.

[0028] In the cathode preparation method of this invention, the first and second methods use an unconventional perovskite-structured Co-based cathode catalyst YCBCo. This utilizes its Co-based properties to ensure its catalytic activity and battery output power. At the same time, its chemical composition, similar to that of the electrolyte material, ensures similar sintering characteristics and chemical compatibility between the two. Its low coefficient of thermal expansion also satisfies the physical compatibility with the electrolyte material, thereby satisfying the good interfacial bonding force between the two materials, achieving excellent mechanical strength of the battery, and ultimately realizing the high-performance long-term stable operation of H-SOFC.

[0029] In the cathode preparation method of the present invention, in the third method, BaCe 0.8 Y 0.2 O 3-δ The material is an excellent proton conductor with high sintering activity, but it is rarely used in practical applications because it readily reacts with common catalyst materials. This invention utilizes the reaction characteristics between materials to achieve excellent interfacial compatibility between the catalyst and the framework, and strong mechanical bonding between the framework and the electrolyte. Furthermore, the microstructure of the cathode can be controlled by adjusting the concentration of the cobalt nitrate solution. Cobalt nitrate reacts in situ with the BCY electrolyte to generate YCBCo. Low-concentration cobalt nitrate solution only induces the generation of YCBCo nanoparticles that are discretely distributed on the surface of the BCY porous framework. High-concentration cobalt nitrate solution can induce the generation of continuous YCBCo nanofilms that densely coat the BCY porous framework, thereby obtaining a BCY@YCBCo core-shell structure. Ultimately, this enables high-performance, long-term stable operation of H-SOFC. Attached Figure Description

[0030] Figure 1(a) is a schematic diagram of the single-phase porous YCBCo cathode structure provided in an embodiment of the present invention;

[0031] Figure 1(b) is a schematic diagram of the YCBCo-BZCY composite cathode structure with discretely distributed YCBCo nanoparticles provided in the embodiment of the present invention;

[0032] Figure 1(c) shows the BZCY@YCBCo core-shell structure cathode densely coated with YCBCo nanofilm provided in the embodiment of the present invention;

[0033] Figure 1(d) is a schematic diagram of the YCBCo-BCY composite cathode structure with discretely distributed YCBCo nanoparticles provided in the embodiment of the present invention;

[0034] Figure 1(e) shows the BCY@YCBCo core-shell structure cathode densely coated with YCBCo nanofilm provided in the embodiment of the present invention;

[0035] Figure 2 The Y-type proton-type solid oxide fuel cell cathode provided in this embodiment of the invention. 1-x Ce x BaCo4O 7+δ XRD pattern of the material. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] This invention proposes a novel cathode catalytic material, Y, with great potential for practical application. 1-x Ce x BaCo4O 7+δ (0≤x<1, 0≤δ<1, abbreviated as YCBCo). Studies have shown that YCBCo material exhibits excellent O2 adsorption / desorption properties in the low-temperature range of 200℃~400℃, which will greatly benefit the oxygen surface process of cathode ORR. Simultaneously, as a Co-based material, YCBCo possesses sufficiently excellent electronic conductivity, with an electronic conductivity of 70±10 Scm in the range of 600℃±100℃. -1 Most notably, unlike other Co-based catalysts, the thermal expansion coefficient of YCBCo material is well-matched with commonly used electrolyte materials such as BZCY, with a coefficient of thermal expansion of (9.20±1.00)×10⁻⁶. -6 K -1 It possesses excellent physical compatibility with electrolyte materials. Based on these advantages, selecting YCBCo material as the cathode for H-SOFC can achieve excellent interfacial bonding with electrolyte materials while meeting catalytic activity requirements, thereby ensuring the battery's output power and long-term operational stability.

[0038] The method of the present invention will be further described in detail below with reference to specific embodiments.

[0039] Examples 1-4 describe methods for preparing single-phase porous YCBCo cathodes.

[0040] Example 1

[0041] S1: Dissolve the nitrates of Y, Ba, Ce, and Co in deionized water, respectively. Use glycine as a combustion aid and calcine at 950℃ for 5 hours to obtain black YCBCo powder.

[0042] S2: Grind the black YCBCo powder and binder thoroughly and evenly into a cathode paste, print it onto the electrolyte surface, and calcine it at 1030℃ for 2.1h in an air atmosphere to obtain a single-phase porous YCBCo cathode.

[0043] Example 2

[0044] S1: Dissolve the nitrates of Y, Ba, Ce, and Co in deionized water, respectively. Use glycine as a combustion aid and calcine at 990℃ for 3 hours to obtain black YCBCo powder.

[0045] S2: Grind the black YCBCo powder and binder thoroughly and evenly into a cathode slurry, print it onto the electrolyte surface, and calcine it at 1100℃ for 1.5h in an air atmosphere to obtain a single-phase porous YCBCo cathode.

[0046] Example 3

[0047] S1: Dissolve the nitrates of Y, Ba, Ce, and Co in deionized water, respectively. Use glycine as a combustion aid and calcine at 960℃ for 3.5 h to obtain black YCBCo powder.

[0048] S2: Grind the black YCBCo powder and binder thoroughly and evenly into a cathode paste, print it onto the electrolyte surface, and calcine it at 1000℃ for 2.5h in an air atmosphere to obtain a single-phase porous YCBCo cathode.

[0049] In Examples 1-3, the binder content and the mass percentage of each content are respectively: a mixture of 4 wt.% ethyl cellulose and 96 wt.% terpineol.

[0050] Example 4

[0051] S1: Preparation of YCBCo material: Y, Ba, Ce and Co nitrates are dissolved in deionized water, and glycine is used as a combustion aid. The mixture is calcined at 1000℃ for 4 hours to obtain black YCBCo phase powder.

[0052] S2: YCBCo powder and binder (4wt.% ethyl cellulose and 96wt.% terpineol) are thoroughly and uniformly ground into a cathode slurry, screen-printed onto the electrolyte surface, and calcined at 1050℃ for 2 hours in air atmosphere to obtain a porous YCBCO cathode.

[0053] Examples 5-8 are YCBCo-BCY composite cathodes with discrete distribution of YCBCo nanoparticles.

[0054] Example 5

[0055] S1: Will Ba 1-x Zr x Ce 1-y Y y O 3-δ Electrolytes and binders are thoroughly and uniformly ground into a skeleton slurry, which is then screen-printed onto the electrolyte surface and calcined at 1000℃ for 2.5 hours in air to obtain a porous BZCY skeleton, wherein Ba 1-x Zr x Ce 1-y Y y O 3-δ Abbreviated as BZCY, where 0 < x < 1, 0 < y < 1.

[0056] S2: Dissolve the nitrates of Y, Ba, Ce, and Co in isopropanol to obtain a first solution. Dissolve glycine and polyvinylpyrrolidone in deionized water to obtain a second solution. Add the second solution dropwise to the first solution to obtain a clear and transparent YCBCo impregnation precursor solution. When preparing the second solution, the amount of glycine added is 1.3 times the amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 6% of the total mass of nitrates and glycine.

[0057] S3: First, the YCBCo impregnation precursor solution is injected into the porous BZCY framework, then treated under negative pressure for 0.5 h, and then calcined at 1000℃ for 3 h in air atmosphere to obtain the YCBCo-BZCY composite porous cathode. In the YCBCo-BZCY composite porous cathode, YCBCo is in the form of nanoparticles, which are uniformly dispersed on the BZCY framework. The particle size range of the YCBCo nanoparticles in the YCBCo-BZCY composite porous cathode is 40 nm to 90 nm.

[0058] Example 6

[0059] S1: Will Ba 1-x Zr x Ce 1-y Y y O 3-δElectrolyte and binder are thoroughly and uniformly ground into a skeleton slurry, which is then screen-printed onto the electrolyte surface and calcined at 1100℃ for 1.5 hours in air to obtain a porous BZCY skeleton, wherein Ba 1-x Zr x Ce 1-y Y y O 3-δ Abbreviated as BZCY, where 0 < x < 1, 0 < y < 1.

[0060] S2: Dissolve the nitrates of Y, Ba, Ce, and Co in isopropanol to obtain a first solution. Dissolve glycine and polyvinylpyrrolidone in deionized water to obtain a second solution. Add the second solution dropwise to the first solution to obtain a clear and transparent YCBCo impregnation precursor solution. When preparing the second solution, the amount of glycine added is 1.4 times the amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 4% of the total mass of nitrates and glycine.

[0061] S3: First, the YCBCo impregnation precursor solution is injected into the porous BZCY framework, then treated under negative pressure for 1.0 h, and then calcined at 950℃ for 5 h in air atmosphere to obtain the YCBCo-BZCY composite porous cathode. In the YCBCo-BZCY composite porous cathode, YCBCo is in the form of nanoparticles, which are uniformly dispersed on the BZCY framework. The particle size range of the YCBCo nanoparticles in the YCBCo-BZCY composite porous cathode is 20 nm to 50 nm.

[0062] Example 7

[0063] S1: Will Ba 1-x Zr x Ce 1-y Y y O 3-δ Electrolyte and binder were thoroughly and uniformly ground into a skeleton slurry, which was then screen-printed onto the electrolyte surface and calcined at 1050℃ for 2.1 hours in air to obtain a porous BZCY skeleton, wherein Ba 1-x Zr x Ce 1-y Y y O 3-δ Abbreviated as BZCY, where 0 < x < 1, 0 < y < 1.

[0064] S2: Dissolve the nitrates of Y, Ba, Ce, and Co in isopropanol to obtain a first solution. Dissolve glycine and polyvinylpyrrolidone in deionized water to obtain a second solution. Add the second solution dropwise to the first solution to obtain a clear and transparent YCBCo impregnation precursor solution. When preparing the second solution, the amount of glycine added is 1.2 times the amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 5% of the total mass of nitrates and glycine.

[0065] S3: First, the YCBCo impregnation precursor solution is injected into the porous BZCY framework, then treated under negative pressure for 0.8 h, and then calcined at 1050 °C for 4 h in air atmosphere to obtain the YCBCo-BZCY composite porous cathode. In the YCBCo-BZCY composite porous cathode, YCBCo is in the form of nanoparticles, which are uniformly dispersed on the BZCY framework. The particle size range of the YCBCo nanoparticles in the YCBCo-BZCY composite porous cathode is 80 nm to 100 nm.

[0066] In Examples 5-7, the binder content and the mass percentage of each content are respectively: a mixture of 4 wt.% ethyl cellulose and 96 wt.% terpineol.

[0067] Example 8

[0068] S1: The BZCY electrolyte and binder (4wt.% ethyl cellulose and 96wt.% terpineol) are thoroughly and uniformly ground into a skeleton slurry, screen-printed onto the electrolyte surface, and calcined at 1050℃ for 2 hours in air atmosphere to obtain a porous BZCY skeleton.

[0069] S2: Preparation of YCBCo impregnation precursor solution: Y, Ba, Ce, and Co nitrates are dissolved in isopropanol solvent. A very small amount of glycine and polyvinylpyrrolidone are dissolved in deionized water. The latter is added dropwise to the former to obtain a clear and transparent YCBCo impregnation precursor solution. The amount of glycine added is 1.3 times the molar amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 5% of the total mass of nitrates and glycine.

[0070] S3: The YCBCo impregnation precursor solution was injected into the porous BZCY framework and treated under negative pressure for half an hour. Then, it was calcined at 1000℃ for 4 hours in air to obtain a nano-sized YCBCo cathode catalyst and a YCBCo-BZCY composite porous cathode. The YCBCo nanoparticles had a particle size range of 70nm to 90nm. In this embodiment, the concentration of the YCBCo impregnation precursor solution was less than 0.05mol / L, specifically 0.26mol / L.

[0071] Example 9

[0072] S1: Will Ba 1-x Zr x Ce 1-y Y y O 3-δ Electrolytes and binders were thoroughly and uniformly ground into a skeleton slurry, which was then screen-printed onto the electrolyte surface and calcined at 1030℃ for 2.2 hours in air to obtain a porous BZCY skeleton, wherein Ba 1-x Zr x Ce 1-y Y y O 3-δ Abbreviated as BZCY, where 0 < x < 1, 0 < y < 1.

[0073] S2: Dissolve the nitrates of Y, Ba, Ce, and Co in isopropanol to obtain a first solution. Dissolve glycine and polyvinylpyrrolidone in deionized water to obtain a second solution. Add the second solution dropwise to the first solution to obtain a clear and transparent YCBCo impregnation precursor solution. When preparing the second solution, the amount of glycine added is 1.3 times the amount of all metal ion nitrates in the first solution, and the amount of polyvinylpyrrolidone added is 4.5% of the total mass of nitrates and glycine.

[0074] S3: First, the YCBCo impregnation precursor solution was injected into the porous BZCY framework, then treated under negative pressure for 0.8 h, and then calcined at 1040℃ for 3.8 h in air atmosphere to obtain the BCY@YCBCo core-shell structure cathode. In the BCY@YCBCo core-shell structure cathode, YCBCo is in the form of a thin film, coating the surface of the BZCY framework. The critical concentration of the YCBCo impregnation precursor solution is 0.09 mol / L.

[0075] Examples 10-13 describe methods for preparing BCY@YCBCo core-shell structured cathodes densely coated with YCBCo nanofilms.

[0076] Example 10

[0077] S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and binder were thoroughly and uniformly ground into a framework slurry, screen-printed onto the electrolyte surface, and calcined at 1000℃ for 3 hours in air to obtain a porous BCY framework, in which BaCe 0.8 Y 0.2 O 3-δ Abbreviated as BCY, 0 < δ < 1,

[0078] S2: Co(NO3)2 was dissolved in isopropanol to obtain a Co(NO3)2 solution. This Co(NO3)2 solution was injected into a porous BCY framework and treated under negative pressure. Then, it was calcined at 1000°C for 4 hours in air. Co(NO3)2 reacted with BCY in situ to generate the YCBCo phase. The electrode microstructure was controlled by adjusting the concentration of the Co(NO3)2 solution. In this embodiment, a high-concentration Co(NO3)2 solution induced the formation of a continuous YCBCo nanofilm, which densely coated the porous BCY framework to obtain a BCY@YCBCo core-shell structure cathode.

[0079] Example 11

[0080] S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and binder were thoroughly and uniformly ground into a framework slurry, screen-printed onto the electrolyte surface, and calcined at 1100℃ for 1 hour in air to obtain a porous BCY framework, in which BaCe 0.8 Y 0.2 O 3-δ Abbreviated as BCY, 0 < δ < 1,

[0081] S2: Co(NO3)2 was dissolved in isopropanol to obtain a Co(NO3)2 solution. The Co(NO3)2 solution was injected into a porous BCY framework and treated under negative pressure. Then, it was calcined at 1050℃ for 3 hours in air. Co(NO3)2 reacted in situ with BCY to generate the YCBCo phase. The electrode microstructure was controlled by the concentration of the Co(NO3)2 solution. In this embodiment, a low concentration of Co(NO3)2 solution induced the formation of YCBCo nanoparticles on the surface and / or within the BCY framework, forming an in-situ self-assembled YCBCo-BZCY composite cathode.

[0082] Example 12

[0083] S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and binder were thoroughly and uniformly ground into a framework slurry, screen-printed onto the electrolyte surface, and calcined at 1050℃ for 2 hours in air to obtain a porous BCY framework, in which BaCe... 0.8 Y 0.2 O 3-δ Abbreviated as BCY, 0 < δ < 1,

[0084] S2: Co(NO3)2 was dissolved in isopropanol to obtain a Co(NO3)2 solution. This Co(NO3)2 solution was injected into a porous BCY framework and treated under negative pressure. Then, it was calcined at 950°C for 5 hours in air. Co(NO3)2 reacted with BCY in situ to generate the YCBCo phase. The electrode microstructure was controlled by adjusting the concentration of the Co(NO3)2 solution. In this embodiment, a high-concentration Co(NO3)2 solution induced the formation of a continuous YCBCo nanofilm, which densely coated the porous BCY framework to obtain a BCY@YCBCo core-shell structure cathode.

[0085] Example 13

[0086] S1: BaCe 0.8 Y 0.2 O 3-δ (BCY) proton conductor material and binder (4 wt.% ethyl cellulose and 96 wt.% terpineol) are thoroughly and uniformly ground into a skeleton slurry, screen printed onto the electrolyte surface, and calcined at 1050℃ for 2 hours in air atmosphere to obtain a porous BCY skeleton.

[0087] S2: Co(NO3)2 is dissolved in isopropanol to obtain a Co(NO3)2 solution, which is then injected into a porous BCY framework. After being treated in a negative pressure environment for half an hour, it is calcined at 1000℃ for 4 hours in an air atmosphere. Co(NO3)2 will react with BCY in situ to generate some YCBCo nanoparticles on the surface of the BCY framework.

[0088] In the above embodiments, high-concentration Co(NO3)2 solution and low-concentration Co(NO3)2 solution are relative concepts, without a very strict numerical range, only an approximate degree. That is, when the concentration of Co(NO3)2 solution increases to a certain range, the generated YCBCo exists in the form of a nanofilm and densely coats the porous BCY framework. When the concentration of Co(NO3)2 solution decreases to a certain range, the generated YCBCo exists in the form of particles, located on or within the porous BCY framework. The critical value of Co(NO3)2 concentration is between 0.05 mol / L and 0.1 mol / L, which is a statistical value from a large amount of experimental data. In specific engineering practice, the critical value of Co(NO3)2 concentration will fluctuate within the concentration range of 0.05 mol / L to 0.1 mol / L depending on the reaction conditions and specific circumstances.

[0089] Figure 1(a) is a schematic diagram of the single-phase porous YCBCo cathode structure provided in the embodiment of the present invention. As can be seen from the figure, the cathode contains only one component, YCBCo. After the YCBCo paste is screen-printed on the surface of the BZCY electrolyte, it is sintered at high temperature to form a porous junction cathode.

[0090] Figure 1(b) is a schematic diagram of the YCBCo-BZCY composite cathode structure with discretely distributed YCBCo nanoparticles provided in the embodiment of the present invention. As shown in the figure, the cathode contains two components: YCBCo and BZCY. After the BZCY paste is screen-printed on the surface of the BZCY electrolyte, it is sintered at high temperature to form a porous BZCY framework. Then, a low-concentration YCBCo impregnation solution is injected into the BZCY framework. Finally, the impregnation solution forms YCBCo nanoparticles at high temperature and is discretely distributed on the surface of BZCY.

[0091] Figure 1(c) shows the BZCY@YCBCo core-shell structure cathode densely coated with YCBCo nanofilm provided in the embodiment of the present invention. As shown in the figure, the cathode contains two components: YCBCo and BZCY. After BZCY paste is screen-printed on the surface of BZCY electrolyte, a porous BZCY framework is formed by high-temperature sintering. Subsequently, a high-concentration YCBCo impregnation solution is injected into the BZCY framework. Finally, the impregnation solution forms a YCBCo nanofilm at high temperature and coats the surface of BZCY.

[0092] Figure 1(d) is a schematic diagram of the YCBCo-BCY composite cathode structure with discretely distributed YCBCo nanoparticles provided in the embodiment of the present invention. As shown in the figure, the cathode contains two components: YCBCo and BCY. After BCY paste is screen-printed on the surface of BZCY electrolyte, it is sintered at high temperature to form a porous BCY framework. Subsequently, a low-concentration Co(NO3)2 solution is injected into the BCY framework. Finally, Co(NO3)2 reacts with the BCY on the surface of the framework at high temperature to generate YCBCo nanoparticles that are discretely distributed on the BCY surface.

[0093] Figure 1(e) shows the BCY@YCBCo core-shell structure cathode densely coated with a YCBCo nanofilm according to an embodiment of the present invention. As shown in the figure, the cathode contains two components: YCBCo and BCY. After BCY paste is screen-printed onto the surface of the BCBCo electrolyte, it is sintered at high temperature to form a porous BCY framework. Subsequently, a high-concentration Co(NO3)2 solution is injected into the BCY framework. Finally, Co(NO3)2 reacts with the BCY on the surface of the framework at high temperature to generate a YCBCo film that coats the BCY surface.

[0094] Figure 2 The Y-type proton-type solid oxide fuel cell cathode provided in this embodiment of the invention. 1-x Ce x BaCo4O 7+δ The XRD pattern of the material shows that Y 1-x Ce x BaCo4O 7+δ It belongs to the close-packed hexagonal space group P63mc.

[0095] The proton-type solid oxide fuel cells fabricated from the above cathodes have excellent performance, specifically reflected in: 1) excellent output power in the low-temperature range; 2) excellent mechanical structural stability; 3) excellent long-term working stability; and 4) good prospects for practical applications.

[0096] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A protonic solid oxide fuel cell cathode, characterized by, Y 1-x Ce x BaCo4O 7+δ as a cathode catalytic material, Y 1-x Ce x BaCo4O 7+δ is abbreviated as YCBCo, wherein 0≤x<1, 0≤δ<1, YCBCo in the low temperature range of 200 °C ~ 400 °C meets the requirements of the cathode of the proton-type solid oxide fuel cell in terms of oxygen absorption / desorption performance, and the electronic conductivity is 70±10 S cm in the range of 600 °C±100 °C -1 The thermal expansion coefficient of the YCBCo material is (9.20±1.00)×10 -6 K -1 , The cathode is a BCY@YCBCo core-shell structure cathode with YCBCo nanofilm dense coating of BCY porous framework, BaCe 0.8 Y 0.2 O 3-δ abbreviated BCY, 0 < δ < 1, The preparation method of the cathode is as follows: S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and the binder are fully and uniformly ground into a skeleton slurry, which is screen printed onto the surface of the electrolyte, calcined at 1000-1100 °C for 1-3 h in an air atmosphere to obtain a porous BCY skeleton, wherein BaCe 0.8 Y 0.2 O 3-δ abbreviated as BCY, 0<δ<1, S2: Co(NO3)2 is dissolved in isopropyl alcohol solvent to obtain a Co(NO3)2 solution, the Co(NO3)2 solution is injected into the porous BCY framework, and is treated in a negative pressure environment, and then is calcined at 950 °C~1050 °C in an air atmosphere for 3h~5h, Co(NO3)2 reacts with BCY in situ to generate YCBCo phase, and an in-situ self-assembled YCBCo-BCY composite cathode is obtained, In step S2, the micro-morphology of the YCBCo-BCY composite cathode is controlled by the concentration of the Co(NO3)2 solution, and the Co(NO3)2 solution with a concentration higher than a critical concentration can induce the generation of continuous YCBCo nanofilm and dense coating of the BCY porous framework, and a BCY@YCBCo core-shell structure cathode is obtained, The critical concentration is in the range of 0.05ml / L~0.1mol / L.

2. A fuel cell comprising the cathode of the proton-type solid oxide fuel cell as claimed in claim 1.

3. A method for producing a cathode for a protonic solid oxide fuel cell as claimed in claim 1, characterized in that, It comprises the following steps: S1: BaCe 0.8 Y 0.2 O 3-δ The proton conductor material and the binder are fully and uniformly ground into a skeleton slurry, which is screen printed onto the surface of the electrolyte, calcined at 1000°C to 1100°C for 1h to 3h in an air atmosphere to obtain a porous BCY skeleton, wherein BaCe 0.8 Y 0.2 O 3-δ is abbreviated as BCY, 0<δ<1, S2: Co(NO3)2 is dissolved in isopropyl alcohol solvent to obtain a Co(NO3)2 solution, the Co(NO3)2 solution is injected into the porous BCY framework, and is treated in a negative pressure environment, and then is calcined at 950 °C~1050 °C in an air atmosphere for 3h~5h, Co(NO3)2 reacts with BCY in situ to generate YCBCo phase, and an in-situ self-assembled YCBCo-BCY composite cathode is obtained, In step S2, the micro-morphology of the YCBCo-BCY composite cathode is controlled by the concentration of the Co(NO3)2 solution, and the Co(NO3)2 solution with a concentration higher than a critical concentration can induce the generation of continuous YCBCo nanofilm and dense coating of the BCY porous framework, and a BCY@YCBCo core-shell structure cathode is obtained, The critical concentration is in the range of 0.05ml / L~0.1mol / L.

4. The method for producing a cathode of a proton-type solid oxide fuel cell according to claim 3, characterized by, The binder comprises the following components and the mass percentage of each component is respectively: 4 wt.% ethyl cellulose and 96 wt.% terpineol.

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