Preparation method of nano-core-shell structure YDC@BCY dual ion conductor ceramic

Abstract

The present invention discloses a method for preparing a nano-core-shell structured YDC@BCY dual-ion conductor ceramic, belonging to the field of solid electrolyte materials. The preparation process is as follows: Y(NO3)3·6H2O and Ce(NO3)3·6H2O are dissolved in deionized water and stirred thoroughly to obtain solution I; Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O are dissolved in deionized water and stirred thoroughly to obtain solution II; sodium dodecyl sulfate (SDS), a surfactant, is dissolved in deionized water and stirred thoroughly, and then added to the above solutions I and II, respectively, to form a uniform and stable dispersion system to obtain solutions IV and V; then, solutions IV and V are thoroughly mixed to in-situ generate nano-core-shell structured YDC@BCY, which is then rapidly hot-pressed to obtain the core-shell structured YDC@BCY dual-ion conductor ceramic. According to equivalent circuit fitting, the conductivity of the YDC@BCY dual-ion conductor ceramic at 600°C in air atmosphere can reach 0.77×10 ‑2 S / cm 2 .

Description

Technical Field

[0001] The invention relates to a preparation method of nano core-shell structure YDC@BCY dual ion conductor ceramics, belonging to the field of solid electrolyte materials. Background Art

[0002] CeO2 is an important oxygen ion conductor solid electrolyte. Compared with the traditional Y2O3 stabilized ZrO2 (YSZ) electrolyte, it has higher ionic conductivity and can operate at lower temperatures. It is expected to become an ideal electrolyte material for solid oxide fuel cells. However, CeO2-based solid electrolytes are prone to non-negligible electronic conductivity in a reducing atmosphere. Therefore, a second phase is often introduced to protect CeO2 grains to prevent them from having electronic conductivity. Proton conductors such as cerates (BaCeO3) can be used as a second phase. It is a good proton conductor in hydrogen or moist air. Due to H + The radius is small and the migration activation energy is low. The interface between BaCeO3 / CeO2 can also serve as a H + and O 2- As a typical proton conductor, BaCeO3 has a higher melting point and a more stable structure than carbonates.

[0003] The existing technology has selected appropriate elements to be doped with CeO2 and BaCeO3 to prepare nanopowders with a core-shell structure, but the nanopowders with a core-shell structure prepared by the generally used synthesis method still have problems such as excessively large powder particle size, irregular powder shape, separation of the two-phase interface, discontinuous and discontinuous two-phase interface, and low electrical conductivity.

[0004] The present invention improves the existing synthesis method to obtain a dense BaCeO3-CeO2 composite electrolyte while achieving and maintaining the continuity and stable distribution of the two-phase interface, thereby overcoming the shortcomings and deficiencies of the existing process methods and opening up a new way to improve the conductivity of CeO2-based electrolytes. Summary of the Invention

[0005] In order to solve the problems existing in materials prepared by existing processes, the present invention provides a method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, which is prepared according to the following steps:

[0006] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were dissolved in deionized water. Ammonia was added dropwise to adjust the pH value during stirring. The mixture was mixed well to obtain Solution I.

[0007] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2 and Y(NO3)3·6H2O were dissolved in deionized water. Ammonia water was added dropwise to adjust the pH during stirring and the mixture was mixed to obtain solution II.

[0008] (3) The surfactant sodium dodecyl sulfate (SDS) was dissolved in deionized water and stirred thoroughly to prepare solution III.

[0009] (4) Add solution III to solution I to obtain a uniform and stable dispersion system solution IV, and add solution III to solution II to obtain a uniform and stable dispersion system solution V.

[0010] (5) After solution IV and solution V are fully mixed, ammonia water is added to adjust the pH of the mixture, and the mixture is placed in an autoclave for reaction. The filter cake obtained by vacuum filtration is repeatedly washed with deionized water and anhydrous ethanol, and the solid phase is collected; the solid phase is dried under vacuum conditions and calcined to obtain a core-shell structured YDC@BCY nanopowder material.

[0011] (6) Sintering the core-shell YDC@BCY nanopowder material obtained in step (5) in a rapid hot pressing sintering furnace to obtain a core-shell YDC@BCY dual ion conductor ceramic. Preferably, the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O in the solution I prepared in step (1) is 1:0.15, and the pH is adjusted to 10.

[0012] Preferably, the solution II prepared in step (2) has a molar ratio of Ce(NO3)3·6H2O, Y(NO3)3·6H2O and Ba(CH3COO)2 of 1:0.15:1 and a pH of 10.

[0013] Preferably, in step (3), the amount of surfactant sodium dodecyl sulfate (SDS) added to deionized water is 0.2 mol / L, and the mixture is stirred at 60° C. for 15 to 20 minutes.

[0014] Preferably, in step (4), the volume ratio of solution I to solution III is 1:0.9, and the volume ratio of solution II to solution III is 1:1.7.

[0015] Preferably, in step (5), the volume ratio of solution IV to solution V is 1:1, the pH is adjusted to 10, and the reaction conditions in the autoclave are 80-120° C. for 12-24 h.

[0016] Preferably, the vacuum drying temperature in step (5) is 110° C. and the time is 8 h to 12 h.

[0017] Preferably, the calcination temperature in step (5) is 800° C. and the calcination time is 5 to 6 hours.

[0018] Preferably, the core-shell structured YDC@BCY nanopowder material obtained in step (5) has a particle size of 20 to 50 nm.

[0019] Preferably, the hot pressing sintering conditions in step (6) are 13 MPa, 1200° C., and sintering for 15 min.

[0020] In the present invention, YDC refers to Y-CeO2 (yttrium-doped cerium oxide), and BCY refers to Y-BaCeO3 (yttrium-doped barium cerate).

[0021] Principle of the present invention:

[0022] Since the barium precursor in the solution is completely dissolved to form Ba 2+ , while CeO2 is not completely dissolved, and partially hydrolyzes to form a soluble cerium hydroxide complex Ce(OH) x 4-x , Ba in solution 2+ Reacts with some of the remaining CeO2 particles to form a BaCeO3 thin layer, and some Ba 2+ or Ba(OH) + with Ce(OH) x 4-x The reaction produces BaCeO3. Both processes occur as in-situ reactions on the CeO2 matrix and in the solution, ultimately producing a nano-YDC@BCY core-shell structure. The present invention uses in-situ reactions to prepare a core-shell structure powder with a nano-CeO2 core and a doped BaCeO3 shell. The powder has a regular, nearly spherical shape and a particle size of 20 to 50 nm. Combined with a subsequent rapid hot pressing sintering process, a dense BaCeO3-CeO2 composite electrolyte ceramic is obtained, which helps maintain the continuity and stability of the two-phase interface, thereby improving conductivity.

[0023] Beneficial effects of the present invention

[0024] (1) The preparation method of the present invention uses a rapid hot pressing sintering process to obtain dense BaCeO3-CeO2 composite electrolyte ceramics, which is beneficial to maintaining the continuity and stability of the two-phase interface and thus improving the conductivity, thereby overcoming the shortcomings and deficiencies of the existing process methods and opening up a new way to improve the conductivity of CeO2-based electrolytes.

[0025] (2) The powder material prepared by the method of the present invention has a more regular and nearly spherical shape and a particle size of 20 to 50 nm, which helps to construct a two-phase interface and thus improve the electrical conductivity.

[0026] (3) The conductivity of the dual ion conductor ceramic prepared by the method of the present invention can reach 0.77×10 -2 S / cm 2 .

[0027] (4) The YDC@BCY core-shell nanopowder prepared by the present invention exhibits no impurity phases in its XRD pattern, and all elements are evenly distributed in the sample with no segregation. This demonstrates that the preparation method employed by the present invention is scientific and rational, capable of producing the desired substance according to a predetermined design.

[0028] (5) The core-shell structured nanopowder prepared by the present invention has good uniformity, the raw materials are easily available, the synthesis method is simple, and the economic cost is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 Schematic diagram of the reaction mechanism of the in situ generated nano core-shell structure YDC@BCY.

[0030] Figure 2 The SEM and particle size distribution diagram of the core-shell structure YDC@BCY nanopowder particles obtained in Example 1.

[0031] Figure 3 This is the XRD pattern of the core-shell structure YDC@BCY nanopowder in Example 1.

[0032] Figure 4 This is the impedance spectrum of the core-shell structure YDC@BCY dual ion conductor ceramic obtained in Example 1 measured at 600°C in an air atmosphere.

[0033] Figure 5 The SEM and particle size distribution diagram of the core-shell structure YDC@BCY nanopowder particles obtained in Example 2.

[0034] Figure 6 The impedance spectrum of the core-shell structure YDC@BCY dual ion conductor ceramic obtained in Example 2 was measured at 600°C in an air atmosphere.

[0035] Figure 7 SEM and particle size distribution of the core-shell structured YDC@BCY nanopowder particles obtained in Example 3.

[0036] Figure 8 The impedance spectrum of the core-shell structure YDC@BCY dual ion conductor ceramic obtained in Example 3 was measured at 600°C in an air atmosphere.

[0037] Figure 9 The impedance spectrum of the core-shell structure YDC@BCY dual ion conductor ceramic obtained in Comparative Example 1 was measured at 600°C in an air atmosphere.

[0038] Figure 10 SEM and particle size distribution of the core-shell structured YDC@BCY nanopowder particles obtained in Comparative Example 2. DETAILED DESCRIPTION

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation examples, but the protection scope of the present invention is not limited to the contents described above.

[0040] Example 1

[0041] A method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, the specific steps are as follows:

[0042] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were weighed in a stoichiometric ratio and dissolved in deionized water. The mixture was stirred at 30°C for 30 min. Ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain Solution I, in which the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O was 1:0.15.

[0043] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O were weighed in stoichiometric proportions and dissolved in deionized water. The mixture was stirred at 30°C for 30 min, and aqueous ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain solution II, in which the molar ratio of Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O was 1:1:0.15.

[0044] (3) Sodium dodecyl sulfate (SDS) was dissolved in deionized water at a concentration of 0.2 mol / L and stirred at 60°C for 15 min to obtain solution III.

[0045] (4) Solution III was added to solution I to obtain solution IV, and solution III was added to solution II to obtain solution V. The mixture was stirred at 60°C for 30 min to form a uniform and stable dispersion system, wherein the volume ratio of solution I to solution III was 1:0.9, and the volume ratio of solution II to solution III was 1:1.7.

[0046] (5) Solution IV and solution V were fully mixed in a volume ratio of 1:1. Ammonia water was added during the stirring process to adjust the pH of the mixture to 10. Ultrasonic vibration was performed uniformly. The mixture was placed in an autoclave and reacted at a temperature of 80°C for 12 hours. The filter cake obtained by vacuum filtration was repeatedly washed with deionized water and anhydrous ethanol, and the solid phase was collected. The solid phase was dried at 110°C under vacuum conditions for 8 hours and calcined at 800°C for 5 hours to obtain a core-shell structured YDC@BCY nanopowder material.

[0047] (6) The core-shell structure YDC@BCY nanopowder was sintered in a rapid hot pressing furnace at 13MPa and 1200℃ for 15min to obtain core-shell structure YDC@BCY dual ion conductor ceramics.

[0048] The core-shell structure YDC@BCY nanopowder prepared in step (5) of this example was tested by scanning electron microscopy. Figure 2 As shown in the figure, it can be seen that the powder particles are evenly distributed and regular and nearly spherical, the powder particle size is 20-50nm, and the average particle size is 36.23nm.

[0049] The core-shell structure YDC@BCY nanopowder prepared in step (5) of this example was subjected to X-ray phase analysis. The results are as follows: Figure 3 As shown in the figure, it can be seen that there is no impurity phase in the XRD diagram, and all elements are evenly distributed in the sample without segregation. This shows that the preparation method used in the present invention is scientific and reasonable, and can produce the required substance according to the predetermined design.

[0050] The core-shell structure YDC@BCY dual ion conductor ceramic prepared in step (6) of this embodiment was subjected to an AC impedance test at 600°C in air atmosphere. According to the equivalent circuit fitting, the results are as follows: Figure 4 As shown, the conductivity is 0.77×10 -2 S / cm 2 .

[0051] Example 2

[0052] A method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, the specific steps are as follows:

[0053] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were weighed in a stoichiometric ratio and dissolved in deionized water. The mixture was stirred at 30°C for 30 min. Ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain Solution I, in which the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O was 1:0.15.

[0054] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O were weighed in stoichiometric proportions and dissolved in deionized water. The mixture was stirred at 30°C for 30 min, and aqueous ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain solution II, in which the molar ratio of Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O was 1:1:0.15.

[0055] (3) Sodium dodecyl sulfate (SDS) was dissolved in deionized water at a concentration of 0.2 mol / L and stirred at 60°C for 20 min to obtain solution III.

[0056] (4) Solution III was added to solution I to obtain solution IV, and solution III was added to solution II to obtain solution V. The mixture was stirred at 60°C for 30 min to form a uniform and stable dispersion system, wherein the volume ratio of solution I to solution III was 1:0.9, and the volume ratio of solution II to solution III was 1:1.7.

[0057] (5) Solution IV and solution V were thoroughly mixed in a volume ratio of 1:1. Ammonia water was added during the stirring process to adjust the pH of the mixture to 10, and ultrasonic vibration was performed to make it uniform. The mixture was placed in an autoclave and reacted at a temperature of 100°C for 12 hours. The filter cake obtained by vacuum filtration was washed alternately with deionized water and anhydrous ethanol, and the solid phase was collected. The solid phase was dried under vacuum conditions for 10 hours and calcined at 800°C for 5 hours to obtain a core-shell structured YDC@BCY nanopowder material.

[0058] (6) The core-shell structure YDC@BCY nanopowder was sintered in a rapid hot pressing furnace at 13MPa and 1200℃ for 15min to obtain core-shell structure YDC@BCY dual ion conductor ceramics.

[0059] The core-shell structure YDC@BCY nanopowder prepared in step (5) of this example was tested by scanning electron microscopy. Figure 5 As shown in the figure, it can be seen that the powder particles are evenly distributed and regular and nearly spherical, the powder particle size is 20-50nm, and the average particle size is 34.90nm.

[0060] The core-shell structure YDC@BCY dual ion conductor ceramic prepared in step (6) of this embodiment was subjected to an AC impedance test at 600°C in air atmosphere. According to the equivalent circuit fitting, the results are as follows: Figure 6 As shown, the conductivity is 0.73×10 -2 S / cm 2 .

[0061] Example 3

[0062] A method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, the specific steps are as follows:

[0063] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were weighed in a stoichiometric ratio and dissolved in deionized water. The mixture was stirred at 30°C for 30 min. Ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain Solution I, in which the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O was 1:0.15.

[0064] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O were weighed in stoichiometric proportions and dissolved in deionized water. The mixture was stirred at 30°C for 30 min, and aqueous ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain solution II, in which the molar ratio of Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O was 1:1:0.15.

[0065] (3) Sodium dodecyl sulfate (SDS) was dissolved in deionized water at a concentration of 0.2 mol / L and stirred at 60°C for 15 min to obtain solution III.

[0066] (4) Solution III was added to solution I to obtain solution IV, and solution III was added to solution II to obtain solution V. The mixture was stirred at 60°C for 30 min to form a uniform and stable dispersion system, wherein the volume ratio of solution I to solution III was 1:0.9, and the volume ratio of solution II to solution III was 1:1.7.

[0067] (5) Solution IV and solution V were thoroughly mixed in a volume ratio of 1:1. Ammonia water was added during the stirring process to adjust the pH of the mixture to 10, and ultrasonic vibration was performed to make it uniform. The mixture was placed in an autoclave and reacted at a temperature of 120°C for 12 hours. The filter cake obtained by vacuum filtration was washed alternately with deionized water and anhydrous ethanol, and the solid phase was collected. The solid phase was dried at 110°C for 12 hours under vacuum conditions and calcined at 800°C for 6 hours to obtain a core-shell structured YDC@BCY nanopowder material.

[0068] (6) The core-shell structure YDC@BCY nanopowder was sintered in a rapid hot pressing furnace at 13MPa and 1200℃ for 15min to obtain the core-shell structure YDC@BCY dual ion conductor ceramic.

[0069] The core-shell structure YDC@BCY nanopowder prepared in step (5) of this example was tested by scanning electron microscopy. Figure 7 As shown in the figure, it can be seen that the powder particles are evenly distributed and regular and nearly spherical, the powder particle size is 20-60nm, and the average particle size is 36.23nm.

[0070] The core-shell structure YDC@BCY dual ion conductor ceramic prepared in step (6) of this embodiment was subjected to an AC impedance test at 600°C in air atmosphere. According to the equivalent circuit fitting, the results are as follows: Figure 8 As shown, the conductivity is 0.67×10 -2 S / cm 2 .

[0071] Comparative Example 1

[0072] As a comparison, the difference between this comparative example and Example 1 is that sodium lauryl sulfate is not added as a surfactant. The preparation method is basically the same as that of Example 1, specifically:

[0073] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were weighed in a stoichiometric ratio and dissolved in deionized water. The mixture was stirred at 30°C for 30 min. Ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain Solution I, in which the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O was 1:0.15.

[0074] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O were weighed in stoichiometric proportions and dissolved in deionized water. The mixture was stirred at 30°C for 30 min, and aqueous ammonia was added dropwise to adjust the pH to 8-10. The mixture was stirred for 30 min to obtain solution II, in which the molar ratio of Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O was 1:1:0.15.

[0075] (3) Solution I and solution II were fully mixed in a volume ratio of 1:1. Ammonia water was added during the stirring process to adjust the pH of the mixture to 10. Ultrasonic vibration was performed uniformly. The mixture was placed in an autoclave and reacted at 80°C for 12 hours. The filter cake obtained by vacuum filtration was repeatedly washed with deionized water and anhydrous ethanol, and the solid phase was collected. The solid phase was dried at 110°C under vacuum conditions for 8 hours and calcined at 800°C for 5 hours to obtain a core-shell structured YDC@BCY nanopowder material.

[0076] (4) The core-shell structure YDC@BCY nanopowder was sintered in a rapid hot pressing furnace at 13MPa for 15min to obtain the core-shell structure YDC@BCY dual ion conductor ceramic.

[0077] The core-shell structure YDC@BCY dual ion conductor ceramic prepared in step (4) of this comparative example was subjected to an AC impedance test at 600°C in air atmosphere. According to the equivalent circuit fitting, the results are as follows: Figure 9 As shown, the conductivity is 0.24×10 -2 S / cm 2 .

[0078] The core-shell YDC@BCY dual-ion conductor ceramic obtained in this comparative example exhibits significantly lower conductivity than the core-shell YDC@BCY dual-ion conductor ceramic obtained in Example 1. This difference is attributed to the addition of sodium dodecyl sulfate as a surfactant, which, by leveraging its structural properties, fully wets the CeO2 surface, dispersing solid particles due to electrostatic repulsion, enhancing their suspension and dispersibility, and forming a stable dispersion. Furthermore, the micelles formed by sodium dodecyl sulfate, acting as nanostructured units, function as microreactors, providing favorable conditions for the in situ generation of the core-shell YDC@BCY structure, thereby improving conductivity.

[0079] Comparative Example 2

[0080] A method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, the specific steps are as follows:

[0081] (1) Y(NO3)3·6H2O and Ce(NO3)3·6H2O were weighed in a stoichiometric ratio and dissolved in deionized water. The mixture was stirred at 30°C for 30 min. Ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain Solution I, in which the molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O was 1:0.15.

[0082] (2) Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O were weighed in stoichiometric proportions and dissolved in deionized water. The mixture was stirred at 30°C for 30 min, and aqueous ammonia was added dropwise to adjust the pH to 10. The mixture was stirred for 30 min to obtain solution II, in which the molar ratio of Ce(NO3)3·6H2O, Ba(CH3COO)2, and Y(NO3)3·6H2O was 1:1:0.15.

[0083] (3) Sodium dodecyl sulfate (SDS) was dissolved in deionized water at a concentration of 0.2 mol / L and stirred at 60°C for 15 min to obtain solution III.

[0084] (4) Solution I was taken for coprecipitation reaction, and then filtered, repeatedly washed with ethanol, dried, calcined and ground to obtain Y-CeO2 powder.

[0085] (5) Take an appropriate amount of the Y-CeO2 powder prepared above and add it to deionized water and ultrasonically disperse it to obtain a Y-CeO2 suspension, in which the concentration of Y-CeO2 powder in the suspension is 0.4 mol / L; add C solution to the Y-CeO2 suspension, wherein the volume ratio of C solution to Y-CeO2 suspension is 1:0.9, and adjust the pH value to 10 with ammonia water.

[0086] (6) The suspension prepared in step (5) is dropped into solution II, the molar ratio of cerium ions in the suspension to barium ions in solution II does not exceed 1:1, the pH is kept stable at 10, and a coprecipitation reaction is carried out. After that, Y-BaCeO3@Y-CeO2 core-shell nanopowder is obtained by suction filtration, repeated washing with ethanol, drying, calcination and grinding.

[0087] The core-shell structure YDC@BCY nanopowder prepared in step (6) of this example was tested by scanning electron microscopy. The results are as follows: Figure 9 As shown in the figure, it can be seen that the powder particles are evenly distributed and regular and nearly spherical, the powder particle size is 60-200nm, and the average particle size is 127.89nm.

[0088] The core-shell structure YDC@BCY nanopowder prepared in step (6) of this comparative example was sintered in a rapid hot pressing furnace at 13MPa and 1200℃ for 15min to obtain a core-shell structure YDC@BCY dual ion conductor ceramic. The obtained ceramic was subjected to an AC impedance test at 600℃ in air atmosphere. According to the equivalent circuit fitting, the results are as follows: Figure 10 As shown, the conductivity is 0.24×10 -2 S / cm 2 .

[0089] After comparison, it was found that the preparation method of the present invention can indeed obtain YDC@BCY core-shell nanopowders with smaller powder size and higher electrical conductivity.

Claims

1. A method for preparing nano-core-shell structured YDC@BCY dual ion conductor ceramics, characterized by: Prepared by the following steps: (1) Dissolve Y(NO3)3·6H2O and Ce(NO3)3·6H2O in deionized water, add ammonia water dropwise to adjust the pH during stirring, and mix well to prepare solution I; (2) Ce(NO3)3·6H2O, Ba(CH3COO)2 and Y(NO3)3·6H2O were dissolved in deionized water, and ammonia was added dropwise to adjust the pH during stirring. The mixture was mixed to obtain solution II. (3) dissolving the surfactant sodium lauryl sulfate in deionized water and stirring thoroughly to prepare solution III; (4) adding solution III to solution I to obtain a uniform and stable dispersion system solution IV, and adding solution III to solution II to obtain a uniform and stable dispersion system solution V; (5) After thoroughly mixing solution IV and solution V, ammonia water was added to adjust the pH of the mixture, and the mixture was placed in an autoclave for reaction. The filter cake obtained by vacuum filtration was repeatedly washed with deionized water and anhydrous ethanol to collect the solid phase; The solid phase was dried and calcined under vacuum conditions to obtain a core-shell structured YDC@BCY nanopowder material; (6) sintering the core-shell structure YDC@BCY nanopowder material obtained in step (5) in a rapid hot pressing sintering furnace to obtain a core-shell structure YDC@BCY dual ion conductor ceramic; The hot pressing sintering conditions in step (6) are 13 MPa and 1200° C. for 15 minutes.

2. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: The solution I prepared in step (1) has a molar ratio of Ce(NO3)3·6H2O to Y(NO3)3·6H2O of 1:0.15, and its pH is adjusted to 10.

3. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: The solution II prepared in step (2) has a molar ratio of Ce(NO3)3·6H2O, Y(NO3)3·6H2O and Ba(CH3COO)2 of 1:0.15:1, and the pH is adjusted to 10.

4. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: In step (3), the surfactant sodium lauryl sulfate is added in an amount of 0.2 mol / L to deionized water, and stirred at 60° C. for 15 to 20 minutes.

5. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: In step (4), the volume ratio of solution I to solution III is 1:0.9, and the volume ratio of solution II to solution III is 1:1.

7.

6. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: In step (5), the volume ratio of solution IV to solution V is 1:1, the pH is adjusted to 10, and the reaction is carried out in an autoclave at a temperature of 80 to 120° C. for 12 to 24 hours.

7. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: In step (5), the vacuum drying temperature is 110° C. and the time is 8 h to 12 h.

8. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: In step (5), the calcination temperature is 800° C. and the calcination time is 5 to 6 hours.

9. The method for preparing the nano-core-shell structured YDC@BCY dual ion conductor ceramic according to claim 1, characterized in that: The core-shell structured YDC@BCY nanopowder material obtained in step (5) has a particle size of 20 to 50 nm.

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