Fuel electrode material for a solid oxide cell heterostructure interface and method of making

Abstract

A fuel electrode material with a heterostructure interface between a solid oxide battery and its preparation method are disclosed, relating to the field of fuel cells. The electrode material has a metal-oxide heterostructure interface with the structural formula Fe@Pr. 1‑x Bi x BaFe2O 5+δ Where 0 < x ≤ 0.1, and δ represents the oxygen vacancy content. This method precipitates highly dispersed nanoparticles through high-temperature reduction treatment in a hydrogen atmosphere, forming Fe@Pr with a metal-oxide heterostructure interface. 1‑x Bi x BaFe2O 5+δ The deposited nanoparticles in the electrode material significantly enhance its conductivity and catalytic activity. When used as a fuel electrode, it exhibits excellent catalytic activity against reactant gases, while also demonstrating superior electrochemical performance and stability. The material prepared in this invention has a simple composition, a relatively simple synthesis process, and is easy to prepare, showing great promise for application in the field of solid oxide batteries.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide batteries, specifically relating to a fuel electrode material with a heterostructure interface for solid oxide batteries and its preparation method. Background Technology

[0002] Solid oxide cells (SOCs) are high-temperature electrochemical energy conversion devices that offer fuel flexibility and high energy conversion efficiency, enabling bidirectional operation in both solid-state fuel cell (SOFC) and solid-state electrolyzer (SOEC) modes. They can generate electricity using various fuels such as hydrogen, natural gas, and biogas, adapting to different energy structure requirements. Their all-solid-state structure eliminates the risk of leakage and eliminates the need for precious metal catalysts, helping to reduce carbon emissions.

[0003] Traditionally, Ni-YSZ has been the preferred fuel electrode material in SOCs; however, long-term stability issues have significantly limited its wider application, including Ni particle agglomeration, carbon deposition, and Ni oxidation under test conditions. To address these challenges, various perovskite materials have been investigated as potential fuel electrode materials, showing promise as alternatives to nickel-based cermets. Despite some progress, developing fuel electrode materials that can match the performance of conventional Ni-YSZ while maintaining excellent stability remains a significant challenge. Summary of the Invention

[0004] The purpose of this invention is to provide a fuel electrode material with a heterostructure interface for solid oxide batteries and its preparation method. This method regulates the performance of the material by constructing a metal-oxide heterostructure interface, thereby obtaining a fuel electrode material with good conductivity and catalytic activity.

[0005] To achieve the above-mentioned objectives, this invention proposes a fuel electrode material with a heterostructure interface for solid oxide batteries. The electrode material has a metal-oxide heterostructure interface and a structural formula of Fe@Pr. 1- x Bi x BaFe2O 5+δ , where 0<x≤0.1, and δ is the content of oxygen vacancies.

[0006] To achieve the above-mentioned objectives, this invention also proposes a method for preparing the fuel electrode material at the heterostructure interface of the solid oxide battery, the method comprising the following steps:

[0007] Step 1: Weigh out the metal nitrates containing Pr, Bi, Ba and Fe according to the stoichiometric ratio of the materials, and weigh out an appropriate amount of citric acid;

[0008] Step 2: Pour the metal nitrate from Step 1 into a container, add deionized water, stir at a certain temperature until the solution is clear, then add citric acid and ammonia in sequence, adjust the pH value of the solution, and stir until a gel is formed.

[0009] Step 3: Place the gel obtained in Step 2 into a high-temperature oven and dry it until the gel is dry to obtain the precursor;

[0010] Step 4: Grind the precursor obtained in Step 3 and place it in a high-temperature muffle furnace for calcination in air atmosphere to obtain electrode powder.

[0011] Step 5: Calcine and reduce the powder from Step 4 under a reducing atmosphere to obtain an electrode material with a metal-oxide heterostructure interface.

[0012] Preferably, in step one, the metal nitrates containing Pr, Bi, Ba and Fe are Pr(NO3)3·6H2O, Bi(NO3)3·5H2O, Ba(NO3)2 and Fe(NO3)3·9H2O, respectively.

[0013] Preferably, in step one, the molar ratio between the metal ions and citric acid is 1:1.5.

[0014] Preferably, in step two, the pH of the solution is adjusted to 7, and the stirring temperature is 90°C.

[0015] Preferably, in step three, the temperature of the high-temperature drying oven is 180–300°C, and the drying time is 10–24 hours.

[0016] Preferably, in step four, the calcination temperature is 1000–1200℃ and the calcination time is 5–10 h.

[0017] Preferably, in step five, the reducing atmosphere is hydrogen, the reducing temperature is 800℃, and the reducing time is 5 to 10 hours.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention utilizes a matrix material PrBaFe2O 5+δ Bi element is doped at the A site and then subjected to high-temperature reduction treatment in a hydrogen atmosphere to form Fe@Pr with a metal-oxide heterostructure interface. 1-x Bi x BaFe2O 5+δElectrode material. The deposited nanoparticles establish electron conduction channels, enhancing electron transfer capability. The synergistic effect of metal nanoparticle deposition and increased oxygen vacancy concentration significantly improves the conductivity of the electrode material and exhibits good catalytic activity for reactant gases. Simultaneously, the strong interfacial adhesion between the nanoparticles and the matrix prevents nanoparticle coarsening, further improving thermal stability and demonstrating excellent electrochemical performance and stability. The material prepared in this invention has significant advantages in its simple composition, relatively simple synthesis process, and ease of preparation, showing great application prospects in the field of solid oxide batteries. Attached Figure Description

[0020] Figure 1 The Pr prepared in step four of Example 1 0.9 Bi 0.1 BaFe2O 5+δ XRD pattern of electrode powder;

[0021] Figure 2 The Pr prepared in step four of Example 1 0.9 Bi 0.1 BaFe2O 5+δ Electrode powder and Fe@Pr obtained in step five 0.9 Bi 0.1 BaFe2O 5+δ XRD pattern of electrode material;

[0022] Figure 3 The Pr prepared in step four of Example 1 0.9 Bi 0.1 BaFe2O 5+δ Electrode powder and Fe@Pr obtained in step five 0.9 Bi 0.1 BaFe2O 5+δ SEM images of the electrode materials;

[0023] Figure 4 This is a schematic diagram showing the relationship between the coefficient of thermal expansion and temperature of the dense sample strip of the electrode material in Example 1;

[0024] Figure 5 This is a schematic diagram showing the relationship between the electrical conductivity of the electrode material in air and temperature in Example 1;

[0025] Figure 6 This is a schematic diagram showing the relationship between the conductivity of the electrode material under hydrogen gas and temperature in Example 1. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be described in detail and completely below with reference to the accompanying drawings. The described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0027] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0028] Example 1

[0029] Electrode material with heterostructure Fe@Pr 0.9 Bi 0.1 BaFe2O 5+δ The specific preparation process is as follows:

[0030] Step 1: Weigh out the metal nitrates Pr(NO3)3·6H2O, Bi(NO3)3·5H2O, Ba(NO3)2 and Fe(NO3)3·9H2O respectively according to the stoichiometric ratio of materials 0.9:0.1:1:2, and then weigh out the citric acid according to the ratio of metal ions to citric acid = 1:1.5 (molar ratio);

[0031] Step 2: Pour the metal nitrate from Step 1 into a beaker, add 300mL of deionized water, place the mixture on a magnetic stirrer, and stir at 90℃ until the solution is clear. Then add citric acid and ammonia to adjust the pH of the solution to 7. Keep the solution at 90℃ and stir until the water evaporates and a gel is formed.

[0032] Step 3: Place the gel obtained in Step 2 into an oven and dry at 180°C for 12 hours until the gel is dry to obtain the precursor;

[0033] Step 4: Grind the precursor obtained in Step 3, place it in a muffle furnace, and calcine it at 1000℃ for 10 hours in air atmosphere to obtain Pr. 0.9 Bi 0.1 BaFe2O 5+δ The electrode powder, and the XRD pattern of the prepared electrode powder are shown below. Figure 1 As shown, no detectable impurity phases were observed in the XRD pattern of the synthesized powder, confirming that bismuth ions were successfully incorporated into the perovskite lattice.

[0034] Step 5: Pr 0.9 Bi 0.1 BaFe2O 5+δ Electrode powder was reduced at 800℃ for 5 hours in a hydrogen atmosphere to obtain Fe@Pr electrode material with a heterostructure. 0.9 Bi0.1 BaFe2O 5+δ XRD pattern as follows Figure 2 As shown in the image, the results reveal a weak diffraction peak in addition to the main perovskite phase. This peak matches the standard diffraction data for Fe, indicating that the iron nanoparticles exsolve during reduction. SEM images before and after reduction are shown below. Figure 3 As shown, observations indicate that the sample prepared in air has a uniform particle size and a smooth surface; however, after reduction treatment, the surface is uniformly covered with small particles.

[0035] Weigh 3g of Pr prepared in step four 0.9 Bi 0.1 BaFe2O 5+δ Electrode powder was placed into a molding die to form rectangular sample strips, which were then calcined in a muffle furnace at 1150℃ for 10 hours to obtain dense sample strips. The prepared dense sample strips were then placed in a thermal expansion apparatus to test their coefficient of thermal expansion at temperatures ranging from 25 to 1000℃. The test results are as follows: Figure 4 As shown, the average coefficient of thermal expansion of the sample is 17.4 × 10⁻⁶. -6 K -1 .

[0036] The conductivity of the prepared dense sample strips was tested under air and hydrogen conditions, and the test results are as follows: Figure 5 and Figure 6 As shown, in an air atmosphere, Pr 0.9 Bi 0.1 BaFe2O 5+δ The electrical conductivity of Fe@Pr first increases and then decreases with temperature, revealing a transition from a semiconductor phase to a metallic phase. Under a hydrogen atmosphere, Fe@Pr 0.9 Bi 0.1 BaFe2O 5+δ Electrical conductivity increases with increasing temperature.

[0037] Example 2

[0038] Electrode material with heterostructure Fe@Pr 0.95 Bi 0.05 BaFe2O 5+δ The specific preparation process is as follows:

[0039] Step 1: Weigh out the metal nitrates Pr(NO3)3·6H2O, Bi(NO3)3·5H2O, Ba(NO3)2 and Fe(NO3)3·9H2O respectively according to the stoichiometric ratio of materials 0.95:0.05:1:2, and then weigh out the citric acid according to the ratio of metal ions to citric acid = 1:1.5 (molar ratio);

[0040] Step 2: Pour the metal nitrate from Step 1 into a beaker, add 300mL of deionized water, place the mixture on a magnetic stirrer, and stir at 90℃ until the solution is clear. Then add citric acid and ammonia to adjust the pH of the solution to 7. Keep the solution at 90℃ and stir until the water evaporates and a gel is formed.

[0041] Step 3: Place the gel obtained in Step 2 into an oven and dry at 180°C for 12 hours until the gel is dry to obtain the precursor;

[0042] Step 4: Grind the precursor obtained in Step 3, place it in a muffle furnace, and calcine it at 1000℃ for 10 hours in air atmosphere to obtain Pr. 0.95 Bi 0.05 BaFe2O 5+δ Electrode powder;

[0043] Step 5: Pr 0.95 Bi 0.05 BaFe2O 5+δ Electrode powder was reduced at 800℃ for 5 hours in a hydrogen atmosphere to obtain Fe@Pr electrode material with a heterostructure. 0.95 Bi 0.05 BaFe2O 5+δ .

[0044] The characterization results and performance test results of the electrode material prepared in this embodiment are similar to those in Example 1.

[0045] Finally, it should be noted that the present invention is not limited to the above embodiments. The above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A fuel electrode material with a heterogeneous interface in a solid oxide battery, characterized in that, The electrode material is an electrode material with a metal-oxide heterostructure interface, and its structural formula is Fe@Pr. 1-x Bi x BaFe2O 5+δ , where 0<x≤0.1, and δ is the content of oxygen vacancies.

2. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery as described in claim 1, characterized in that, The method includes the following steps: Step 1: Accurately weigh the nitrates containing Pr, Bi, Ba and Fe according to the stoichiometric ratio of the materials, and weigh an appropriate amount of citric acid; Step 2: Pour the metal nitrate from Step 1 into a container, add deionized water, stir at a certain temperature until the solution is clear, then add citric acid and ammonia in sequence, adjust the pH value of the solution, and stir until a gel is formed. Step 3: Place the gel obtained in Step 2 into a high-temperature oven and dry it until the gel is dry to obtain the precursor; Step 4: Grind the precursor obtained in Step 3, place it in a high-temperature muffle furnace, and calcine it in an air atmosphere to obtain electrode powder. Step 5: Calcine and reduce the powder from Step 4 under a reducing atmosphere to obtain a fuel electrode material with a metal-oxide heterostructure interface.

3. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that, In step one, the nitrates containing Pr, Bi, Ba and Fe are Pr(NO3)3·6H2O, Bi(NO3)3·5H2O, Ba(NO3)2 and Fe(NO3)3·9H2O, respectively.

4. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that: In step one, the molar ratio between the metal ions and citric acid is 1:1.

5.

5. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that: In step two, the pH of the solution is adjusted to 7, and the stirring temperature is 90℃.

6. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that: In step three, the high-temperature drying temperature is 180–300℃, and the drying time is 10–24 hours.

7. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that: In step four, the calcination temperature is 1000–1200℃ and the calcination time is 5–10 hours.

8. The method for preparing a fuel electrode material with a heterogeneous interface in a solid oxide battery according to claim 2, characterized in that: In step five, the reducing atmosphere is hydrogen, the temperature is 800℃, and the reduction time is 5 to 10 hours.

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