Preparation method of b-site doped nickel iron-based perovskite material and application thereof in medium-temperature solid oxide fuel cell

Abstract

The application discloses a preparation method of B-site doped nickel iron-based perovskite material and application of the B-site doped nickel iron-based perovskite material in a medium-temperature solid oxide fuel cell, and belongs to the technical field of solid oxide fuel cells. The preparation method of the B-site doped nickel iron-based perovskite material comprises the following steps: dissolving lanthanum salt, calcium salt, iron salt and nickel salt in water to obtain a metal ion solution; dissolving ethylenediaminetetraacetic acid (EDTA) in a solvent, then mixing the EDTA with the metal ion solution and citric acid (CA), and adjusting the pH value to be alkaline to obtain a precursor solution; heating and stirring the precursor solution until the precursor solution becomes a viscous colloid, then evaporating and removing the solvent to obtain a precursor powder, and performing calcination treatment to obtain the B-site doped nickel iron-based perovskite material. The application successfully synthesizes La 0.6 Ca 0.4 Fe 1‑ x Ni x O 3‑δ Cathode material, with high electrochemical performance, more suitable for use as a medium-temperature SOFC cathode material.

Description

Technical Field

[0001] This invention relates to the field of solid oxide fuel cell technology, and in particular to a method for preparing a nickel-doped iron-based perovskite material at the B site and its application in a mid-temperature solid oxide fuel cell. Background Technology

[0002] Global warming and environmental pollution have become among the most serious challenges facing the world today, adversely impacting ecosystems, human health, and socio-economic development. Solid oxide fuel cells (SOFCs) convert the chemical energy stored in fuel into electrical energy without the need for intermediates. However, the high operating temperature (1000℃) leads to problems such as poor battery durability, high cost, and limited material selection, restricting the practical application of SOFCs. Lowering the operating temperature of SOFCs to the intermediate range of 600-800℃ through modification could not only broaden the range of material choices but also slow down the rate of performance degradation; however, current modifications result in a decrease in the catalytic activity of the oxygen reduction reaction (ORR) in the cathode material. Therefore, developing cathode materials with high electrochemical performance is a crucial step towards the commercialization of intermediate-temperature solid oxide fuel cells (IT-SOFCs).

[0003] The prior art disclosed in CN115863671A is a cathode material doped with Ca ions at the A site, a cathode strip, and a method for preparing a symmetrical cell. The material described in this invention has a maximum electrical conductivity of 104.2 S·cm. -1 Although theoretically, MIEC materials should have a cathode strength greater than 100 S·cm. -1 While the material exhibits a certain electrical conductivity, it fails to meet the aforementioned requirements within the actual operating temperature range of 600-800℃, limiting its application potential as a high-performance cathode material. Furthermore, power density is a key parameter for evaluating fuel cell performance, directly determining its practical application value. However, this invention does not test the power density of its material, lacking application-level performance verification, thus reducing its practicality and promotional value. Moreover, a significant difference in TEC (coefficient of thermal expansion) between the cathode and electrolyte will generate substantial thermal stress at the interface, easily leading to microcrack formation and affecting the structural stability and lifespan of the battery. Although the invention indicates that the Fe-based material used has an appropriate TEC, it does not provide TEC test data for the cathode material after Ca ion doping; therefore, the effectiveness of its compatibility with the electrolyte remains to be verified.

[0004] Therefore, further improvements are still needed to achieve synergistic optimization of the conductivity, thermal matching, and electrochemical performance of solid oxide fuel cell cathode materials, and to solve the problems of low electrochemical performance and difficulty in using cathode materials under intermediate temperature conditions. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing nickel-doped iron-based perovskite materials at the B site and their application in intermediate-temperature solid oxide fuel cells, thereby solving the aforementioned problems in the background art. This invention successfully synthesized La with a single perovskite structure. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The cathode material possesses high electrochemical performance and is more suitable for use as a cathode material in medium-temperature SOFCs.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] One of the technical solutions of this invention is to provide a nickel-doped iron-based perovskite material with the chemical formula La for preparing B-site nickel-doped cathodes of solid oxide fuel cells. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Where x is the amount of Ni doping, 0 < x ≤ 0.2, and δ is the oxygen vacancy content, 0.2 < δ ≤ 0.3.

[0008] Preferably, the value of x is 0.1.

[0009] The second technical solution of the present invention provides a method for preparing the above-mentioned nickel-doped iron-based perovskite material at the B site, which is prepared by the EDTA-CA sol-gel method and includes the following steps:

[0010] Lanthanum salt, calcium salt, iron salt and nickel salt are dissolved in water to obtain a metal ion solution; ethylenediaminetetraacetic acid (EDTA) is dissolved in a solvent, and then mixed with the metal ion solution and citric acid (CA), and the pH is adjusted to alkaline to obtain a precursor solution;

[0011] The precursor liquid is heated and stirred until it becomes a viscous colloid, and then the solvent is evaporated to remove it, resulting in a precursor powder. The powder is then calcined to obtain the nickel-doped iron-based perovskite material at the B site.

[0012] Preferably, the solvent is ammonia.

[0013] Preferably, the lanthanum salt is La(NO3)3; and / or, the calcium salt is Ca(NO3)2; and / or, the iron salt is Fe(NO3)3; and / or, the nickel salt is Ni(NO3)2; and / or, the total molar amount of the iron salt and nickel salt is in a molar ratio of 10:6:4 to that of the lanthanum salt and calcium salt, and the molar amount of the nickel salt is in a ratio of 0 to 0.2 and not 0.

[0014] Preferably, the molar ratio of the total molar amount of metal ions in the metal ion solution to that of CA and EDTA is 0.9-1.1:0.9-1.1:1.4-1.6.

[0015] Preferably, the pH value is 8.

[0016] Preferably, the method of heating and stirring the precursor liquid until it becomes a viscous colloid and then evaporating to remove the solvent includes the following steps: heating and stirring the precursor liquid at 80°C until it becomes a viscous colloid, and then heating it at 200°C for 2 hours to obtain a fluffy, black precursor powder.

[0017] Preferably, the calcination treatment is carried out at a temperature of 1000°C for 5 hours; and / or, the calcination treatment is carried out in an air atmosphere.

[0018] The third technical solution of the present invention provides an application of the above-mentioned nickel-doped iron-based perovskite material at the B site in the field of solid oxide fuel cell cathode materials.

[0019] The fourth technical solution of the present invention provides a solid oxide fuel cell, wherein the cathode material of the solid oxide fuel cell contains the above-mentioned nickel-doped iron-based perovskite material at the B site.

[0020] The technical principle of this invention is as follows:

[0021] This invention employs a pretreatment method that dissolves EDTA in ammonia water. EDTA has poor solubility in acidic or neutral solutions, while the alkaline environment provided by ammonia water helps to better dissolve EDTA, facilitating subsequent complexation with metal ions. Simultaneously, ammonia water is a weak base and easily volatilizes, allowing for complete removal during subsequent heating, preventing impurity residues and thus improving the purity of the final product.

[0022] In the preparation process, a molar ratio of n(total metal ions):n(CA):n(EDTA) = 0.9-1.1:0.9-1.1:1.4-1.6 (Group A) was used for ingredient preparation. To determine the optimal ratio, a control experiment was conducted. EDTA, as a strong complexing agent, can form stable complexes with most metal ions. Adjusting the EDTA molar ratio to 0.9-1.1 (Group B) resulted in impurities in the prepared sample, producing NiO impurities. This is because competitive complexation exists between metal ions, leading to incomplete complexation. To ensure complete metal ion complexation, the EDTA molar ratio was increased to 1.9-2.1 (Group C). While this ensured sufficient complexation, it introduced a new problem: particle coarsening occurred in the sample, and the raw material cost also increased significantly. The optimal experimental results were achieved when the EDTA molar ratio was 1.4-1.5 (Group A), resulting in samples with no impurities and small particle sizes. Taking into account factors such as sample purity, performance, and cost, the optimal molar ratio of EDTA was determined to be 1.4-1.6. This ratio can ensure sample quality while achieving rational utilization of resources.

[0023] Although CA, as an auxiliary complexing agent, has weaker complexing ability than EDTA, it can effectively regulate the gel formation rate of the system and prevent uneven gel structure from affecting the final performance. Adjusting the CA molar ratio to 0.4-0.6 (Group D) results in insufficient CA participating in the complexation reaction, leading to incomplete complexation of metal ions and the formation of NiO impurities in the sample. Adjusting the CA molar ratio to 1.4-1.6 (Group E) causes a large amount of residual CA to decompose and generate gas during high-temperature heat treatment, easily forming large pores inside the material, allowing O2 to escape without sufficient reaction and reducing gas utilization. Simultaneously, the effective reaction area around the large pores decreases sharply, leading to reduced oxygen reduction reaction activity. Adjusting the CA molar ratio to 0.9-1.1 (Group A) helps achieve a uniform distribution of metal ions, thus obtaining a high-purity target perovskite material without significant agglomeration after calcination. This invention uses La... 0.6 Ca 0.4 FeO 3-δ Using Ni as the matrix material, the La 0.6 Ca 0.4 FeO 3-δ By doping the B site, X-ray diffraction (XRD) results showed that La with a single perovskite structure was successfully synthesized. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ For the cathode materials, apart from the peaks corresponding to the cathode and SDC electrolyte, no additional peaks were observed for any of the materials studied, indicating that no chemical reaction occurs between them and the SDC electrolyte, and that they have good chemical compatibility.

[0024] In the preparation of the precursor solution, this invention adjusts the pH of the reaction system to 8, which has the following three advantages: First, under alkaline conditions, the four carboxylic acid groups (-COOH) of EDTA are almost completely dissociated into carboxylate groups (-COO₂). - First, the alkaline environment allows for more effective formation of stable, soluble complexes with metal ions, avoiding the formation of hydroxide precipitates. Second, the alkaline environment weakens the complexing effect of CA, allowing EDTA to dominate the complexation reaction, thus improving the stability of the complex. CA, on the other hand, participates more in the sol-gel transformation process, avoiding competition with EDTA for metal ions. Third, the alkaline environment regulated by ammonia helps suppress premature hydrolysis of metal ions, enhancing the stability and uniformity of the sol and preventing phase separation or particle aggregation during the gelation stage. The EDS elemental distribution map shows that Ni has been successfully doped into La. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Furthermore, the La, Ca, Fe, Ni, and O elements are evenly distributed, with no obvious elemental segregation.

[0025] During the heating and stirring of the precursor solution until it becomes a viscous colloid, an 80°C water bath with continuous stirring effectively accelerates the complexation reaction rate and promotes the full reaction between the complexing agent and metal ions, thereby forming a homogeneous and stable precursor solution. This temperature condition promotes the complexation reaction while preventing the decomposition of the metal salt at high temperatures. Simultaneously, the constant temperature provided by the water bath helps to uniformly evaporate moisture in the system. Combined with continuous stirring, this further prevents localized overheating and the formation of concentration gradients, ensuring the consistency of the product's composition and structure. Furthermore, controlling the water bath temperature at 80°C effectively prevents the thermal decomposition of EDTA and CA, avoiding the impact of carbon residue on product purity.

[0026] The La of the present invention 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The material also exhibits significant advantages in thermodynamic properties. The coefficient of thermal expansion (TEC) is a key indicator for evaluating the thermal compatibility between electrode materials and electrolytes, directly affecting the structural stability of intermediate-temperature solid oxide fuel cells (IT-SOFCs) during long-term operation. Experimentally measured: La 0.6 Ca 0.4 FeO 3-δ The TEC of the matrix material is 15.38 × 10⁻⁶. -6 K -1 When the Ni doping concentration is x = 0.2, La 0.6 Ca 0.4 Fe 0.8 Ni 0.2O 3-δ The TEC is 13.61 × 10⁻⁶. -6 K -1 It is evident that the gradual doping of Ni significantly suppresses the thermal expansion behavior of the material, which helps to achieve matching with commonly used electrolytes (TECs), thereby improving the structural integrity and service life of the battery.

[0027] This invention, through B-site doping with low-valence Ni ions, leads to Fe... 3+ Oxidized to Fe 4+ To maintain La 0.6 Ca 0.4 Fe 1- x Ni x O 3-δ The electronegativity of Ni leads to the formation of oxygen vacancies, thereby increasing conductivity. With increasing Ni doping concentration, La... 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The conductivity of La gradually increases. 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ It reaches its maximum value (328.53 S·cm) at 500℃. -1 Compared to the matrix (195.05 S·cm), -1 This represents an increase of approximately 68.43%, far exceeding the minimum standard required for IT-SOFC cathode materials (>100 S·cm). -1 ).

[0028] The beneficial technical effects of the present invention are as follows:

[0029] This invention employs the EDTA-CA sol-gel method, using EDTA and CA as complexing agents, and successfully synthesizes La with a single perovskite structure by doping Ni at the B site. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Cathode material. The product exhibits good chemical compatibility and a porous microstructure.

[0030] The modification methods of this invention significantly improve the electrochemical performance of the product, making it more suitable for use as a cathode material in medium-temperature SOFCs. Compared to La... 0.6 Ca 0.4 FeO 3-δ The matrix of this invention significantly improves the conductivity of the product while reducing the electrochemical impedance (Rp), and the peak power density (PPD) reaches 674.62 mW·cm at 800℃.-2 This represents a 73.61% improvement compared to the matrix. Ni doping lowers the TEC of the material, making it more compatible with the SDC electrolyte (12.5 × 10⁻⁶). -6 K -1 The thermal expansion is matched. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 The XRD patterns are those of the products of Example 1 and Comparative Examples 1-4.

[0033] Figure 2 The images shown are SEM images of the products of Example 1 and Comparative Examples 1-4. Specifically, a, b, c, d, and e are SEM images of the products of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively.

[0034] Figure 3 The images show the XRD patterns of the products from Examples 1-2 and magnified XRD patterns within the range of 32.0°≤2θ≤33.0°. Wherein, a is the XRD pattern and b is the magnified XRD pattern within the range of 32.0°≤2θ≤33.0°.

[0035] Figure 4 For LCFN 0.1 |SDC||LCFN 0.1 XRD pattern.

[0036] Figure 5 a, b, c, d, and e represent LCFN|SDC and LCFN, respectively. 0.05 |SDC、LCFN 0.1 |SDC、LCFN 0.15 |SDC、LCFN 0.2 SEM image of the cross section of SDC, where f is the LCFN. 0.1 SEM image of the cross section of |SDC|NiO-SDC.

[0037] Figure 6The images show the HR-TEM image and corresponding Fast Fourier Transform (FFT) pattern of the product in Example 1, as well as the spectral outlines of the selected area electron diffraction (SAED) lattice fringes. Wherein, a, c, and d are the HR-TEM image of the product on the d(110) crystal plane, the FFT pattern marked in a, and the spectral outlines of the SAED lattice fringes, respectively; b, e, and f are the HR-TEM image of the product on the d(100) crystal plane, the FFT pattern marked in b, and the spectral outlines of the SAED lattice fringes, respectively.

[0038] Figure 7 The images show the STEM and EDS elemental distributions of the product from Example 1. In the images, a is the STEM image, and b, c, d, e, and f are the EDS elemental distributions.

[0039] Figure 8 The O1s spectra of the products from Examples 1-2 are shown.

[0040] Figure 9 The graph shows the thermal expansion of the products from Examples 1-2 at temperatures ranging from room temperature to 750°C.

[0041] Figure 10 The graph shows the temperature variation of conductivity of the products from Examples 1-2 measured at 400-800°C.

[0042] Figure 11 The figures show the electrochemical impedance spectroscopy (EIS) and Arrhenius plot of the polarization impedance as a function of temperature for the product of Example 3, measured at 600-800°C. In the figures, a, b, c, d, and e are electrochemical impedance spectroscopy, and f is an Arrhenius plot.

[0043] Figure 12 The graph shows the current density-voltage-power density (IVP) curves of the product of Example 4 measured at 600-800°C.

[0044] Where a is LCFN|SDC|NiO-SDC, and b is LCFN 0.1 |SDC|NiO-SDC. Detailed Implementation

[0045] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention. It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the present invention.

[0046] Furthermore, regarding the numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Any stated value or intermediate value within a stated range, as well as each smaller range between any other stated value or intermediate value within said range, are also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0047] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. It should be noted that any aspects of this invention not described in detail are conventional practices in the art and are not the focus of this invention.

[0048] The terms “comprising,” “including,” “having,” “containing,” etc., used in this invention are all open-ended terms, meaning that they include but are not limited to.

[0049] In terms of materials design strategies, A-site and B-site doping are common methods for optimizing the overall performance of Fe-based perovskite materials. This invention reveals that A-site doping with low-valence cations can release lattice oxygen through a charge compensation mechanism, thereby increasing the oxygen vacancy concentration and enhancing oxygen ion conductivity. In contrast, B-site doping with low-valence cations can induce a change in the valence state of Fe, forming small polaron jumping channels that facilitate electron migration, significantly improving the material's electronic conductivity. Simultaneously, Ni doping can effectively reduce the material's TEC, allowing for better matching with the electrolyte, thereby improving interfacial stability and extending battery life. 2+ / Ni 3 + The multivalent state characteristics can also regulate the concentration of oxygen vacancies, further enhancing the catalytic activity of the material in ORR.

[0050] Therefore, this invention proposes a method for preparing Ni-doped iron-based perovskite cathode materials at B sites and their application in solid oxide fuel cells, aiming to achieve synergistic optimization of conductivity, thermal matching and electrochemical performance, and solve the problem of low electrochemical performance of Fe-based perovskites and difficulty in using them under intermediate temperature conditions.

[0051] Specifically, this invention provides a nickel-doped iron-based perovskite material with the chemical formula La for preparing B-site nickel-doped cathodes of solid oxide fuel cells. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Where x is the amount of Ni doping, 0 < x ≤ 0.2, and δ is the oxygen vacancy content, 0.2 < δ ≤ 0.3.

[0052] This invention also provides a method for preparing the above-mentioned nickel-doped B-site iron-based perovskite material, which is prepared by the EDTA-CA sol-gel method and includes the following steps:

[0053] (1) Dissolve La(NO3)3·6H2O(AR), Ca(NO3)2·4H2O(AR), Fe(NO3)3·9H2O(AR) and Ni(NO3)2·6H2O(AR) in water to obtain a metal ion solution; dissolve ethylenediaminetetraacetic acid (EDTA) in ammonia water, and then slowly add it to the metal ion solution until it is completely dissolved. Then add citric acid (CA) and continue stirring until it is completely dissolved.

[0054] (2) The pH of the mixed solution obtained in step (1) was adjusted to 8 by adding ammonia under magnetic stirring;

[0055] (3) Heat and stir the mixed solution in step (2) with pH adjusted to 8 in a constant temperature water bath at 80°C until it becomes a viscous colloid.

[0056] (4) Place the viscous colloid from step (3) into an evaporating dish and heat it in a universal resistance furnace at 200°C for 2 hours to obtain a fluffy black precursor powder.

[0057] (5) Place the fluffy black precursor powder from step (4) into a crucible, calcine it at 1000℃ in a muffle furnace for 5 hours, and then allow it to cool naturally to obtain La. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Cathode material.

[0058] Furthermore, the volume ratio of EDTA to ammonia is 1:1.15, and the concentration of ammonia is 25%.

[0059] Furthermore, the molar ratio of the total molar amount of metal ions in the metal ion solution to that of citric acid and ethylenediaminetetraacetic acid is 0.9-1.1:0.9-1.1:1.4-1.6.

[0060] Furthermore, the high-temperature calcination is carried out in an air atmosphere.

[0061] The present invention also provides a solid oxide fuel cell, wherein the cathode material of the solid oxide fuel cell comprises the above-mentioned nickel-doped iron-based perovskite material at the B site.

[0062] This invention also provides a performance testing method for the above-mentioned nickel-doped B-site iron-based perovskite material, comprising the following steps:

[0063] (1) Weigh 1.5g of the above B-site doped nickel iron-based perovskite material into a mortar, add polyvinyl butyral (PVB) and anhydrous ethanol and grind thoroughly. After grinding completely dry, put it into a mold, press it under 10 MPa pressure for 2 min, press it into a rectangular strip, and then calcine it in a muffle furnace at 1200℃ for 5 h. After natural cooling, the material used to test electrical conductivity and thermal expansion is obtained.

[0064] (2) Weigh 0.5g of electrolyte cerium oxide (SDC) and put it into a circular mold. Press it under 10MPa pressure for 2min to form a circular SDC electrolyte sheet with a diameter of 15mm. Calcine it in a muffle furnace at 1450℃ for 10h and cool it naturally to obtain a dense SDC electrolyte sheet.

[0065] (3) The above-mentioned nickel-doped iron-based perovskite material was ball-milled for 1 hour and dried in an oven. Then it was mixed with terpineol and ethyl cellulose at a mass ratio of 100:94:6 and manually ground evenly to obtain a cathode paste. The cathode paste was then printed on both sides of the above-mentioned SDC electrolyte sheet by screen printing. The sheet was placed in an oven and baked at 200°C for 12 hours. After that, it was calcined in a muffle furnace at 1000°C for 2 hours and cooled naturally to obtain a symmetrical cell for testing the polarization resistance of the material.

[0066] (4) Mix NiO and SDC at a mass ratio of 6:4, and then ball mill the resulting NiO-SDC mixed powder with corn starch at a mass ratio of 4:1 for 24 hours to obtain composite anode material NiO-SDC powder.

[0067] (5) Place the composite anode material NiO-SDC powder obtained in step (4) into a circular mold, press it under 6MPa pressure for 1min, press it into a disc shape without demolding, spread the electrolyte SDC evenly on the disc, and press the SDC onto the top of the anode under 10MPa pressure; calcine the double-layer disc in a muffle furnace at 1450℃ for 5h, and cool it naturally to obtain the anode sheet;

[0068] (6) The cathode paste obtained in step (3) is printed on the electrolyte side of the anode sheet by screen printing process, and then baked in an oven at 200°C for 12 hours. After that, it is calcined in a muffle furnace at 1000°C for 2 hours and then cooled naturally to obtain an anode-supported battery, which is used to test the power density of the material.

[0069] Furthermore, the calcination process is carried out in an air atmosphere.

[0070] Further, the rectangular strip sample in step (1) has dimensions of 29.0 mm × 6.0 mm × 0.5 mm, and the mass ratio of nickel-doped iron-based perovskite material at B site to polyvinyl butyral is 50:1.

[0071] Furthermore, in step (2), the calcination of the circular SDC electrolyte sheet is carried out in a confined space, specifically by sandwiching the circular SDC electrolyte sheet between two Al2O3 plates before calcination.

[0072] Furthermore, the ball milling medium in steps (3) and (4) is anhydrous ethanol.

[0073] In step (1), polyvinyl butyral (PVB) was added as a binder. This binder enhances the mechanical integrity of the rectangular strip structure during the pressing process, reduces the risk of sample breakage, and effectively inhibits crack formation during subsequent high-temperature calcination. However, as an insulating material, its addition amount must be strictly controlled. In the raw material system of this invention, if its addition amount exceeds a mass ratio of 50:1, it will block ion or electron transport pathways and reduce electrochemical performance. This ratio (50:1) ensures the forming process while also enabling the full decomposition of PVB during calcination, minimizing the negative impact of carbon residue on electrode performance.

[0074] In step (2), to prevent warping or cracking of the circular SDC electrolyte sheets during high-temperature calcination due to uneven heating or inconsistent shrinkage, this invention employs a method of constraining the pressed electrolyte sheets by placing them between Al2O3 plates. Covering the top and bottom with Al2O3 plates of the same size allows for uniform mechanical pressure to be applied during calcination, thereby ensuring the flatness of the sample morphology, improving its mechanical stability, and preventing interference with subsequent performance testing due to warping or deformation. Furthermore, the Al2O3 plates are chemically inert, effectively preventing them from reacting with the SDC electrolyte material. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The SEM image of the cross-section of the SDC electrolyte sheet shows that La 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The cathode material adhered tightly to the SDC electrolyte sheet, and no obvious cracks were observed at the interface, indicating good interfacial bonding performance between the cathode material and the electrolyte. Meanwhile, the SDC electrolyte sheet exhibited a dense structure, while La... 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The material has a porous microstructure, which is conducive to oxygen diffusion, surface oxygen exchange and charge conduction.

[0075] In step (3), the cathode paste is prepared by mixing the cathode material with terpineol and ethyl cellulose in a mass ratio of 100:94:6. Terpineol, as an organic solvent, imparts appropriate viscosity and volatility to the paste, which is beneficial for uniform coating in the screen printing process. Ethyl cellulose has both thickening and binding functions, effectively improving the dispersibility and film uniformity of the paste. If the proportion of terpineol in the paste is too high (e.g., rising to a level equivalent to the cathode mass, 100:100:6), the paste viscosity will be too high, increasing the printing difficulty and affecting the film quality; if the proportion of ethyl cellulose is too high (e.g., 100:94:10), an excessively thick film may form after drying, increasing the resistance to electron or ion transport, and increasing the residual carbon content after calcination, which damages the electrode performance. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Electrochemical impedance spectroscopy (EIS) analysis measured at 600–800 °C showed that Ni doping reduced the Rp of the material, from 0.16 Ω·cm at 800 °C. 2 (La 0.6 Ca 0.4 FeO 3-δ The value decreased to 0.097 Ω·cm 2 (La 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ This improves the electrochemical performance of the battery.

[0076] In step (4), this invention uses a NiO and SDC mixed powder with a mass ratio of 6:4 to construct the anode functional layer, thereby achieving synergistic optimization of the electron and ion conduction pathways. NiO, as an electrocatalyst, not only provides an electron conduction network but also effectively promotes the electrochemical oxidation reaction of fuel gas, while SDC provides excellent oxygen ion conductivity; the 6:4 ratio achieves a good balance between catalytic activity and ionic conductivity. Furthermore, to introduce a suitable pore structure to promote fuel gas transport, corn starch with a mass ratio of 4:1 is added to the NiO-SDC mixed powder as a pore-forming agent. During high-temperature calcination, corn starch can be thermally removed, forming a permeable porous network, significantly improving the gas diffusion performance of the anode layer. However, the amount of pore-forming agent needs to be precisely controlled: insufficient addition will result in excessively low anode porosity and limited gas transport; excessive addition may cause a loose structure and a significant reduction in mechanical strength after sintering. In this invention, the pore-forming agent accounts for 20% of the total mixed powder mass, achieving a good balance between pore formation efficiency and structural stability. From LCFN 0.1The SEM image of the NiO-SDC cross-section shows that the anode is loose and porous, which is beneficial for fuel gas transport. The electrolyte is dense, which can effectively prevent direct contact between the anode and cathode sides and avoid short circuits.

[0077] Performance test results show that, compared with undoped La 0.6 Ca 0.4 FeO 3-δ In comparison, when the Ni doping concentration is x = 0.1, the peak power density (PPD) at 800℃ reaches 674.62 mW·cm⁻¹. -2 Compared to the matrix, PPD increased by 73.61%, significantly enhancing the overall output performance of SOFC.

[0078] All raw materials used in the following embodiments and comparative examples of the present invention are commercially available products.

[0079] Example 1

[0080] A nickel-doped iron-based perovskite material with the chemical formula La (B-site doped nickel) 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ The preparation method for (where δ is 0.25) is as follows:

[0081] (1) Taking the preparation of 5g of iron-based perovskite material as an example, the relative atomic mass of each element was consulted, and its n was calculated to be 0.02457mol. Therefore, 6.3833g, 2.3208g, 8.9335g, and 0.7145g of La(NO3)3·6H2O(AR), Ca(NO3)2·4H2O(AR), Fe(NO3)3·9H2O(AR), and Ni(NO3)2·6H2O(AR) were weighed in sequence and dissolved in 150ml of deionized water to obtain a metal ion solution. 21.5707g of EDTA(AR) was dissolved in 27.3mL of ammonia water (ammonia concentration of 25%), and then slowly added to the metal ion solution until completely dissolved. Then, 10.34055g of CA(AR) was added to the mixed solution and stirred continuously until completely dissolved.

[0082] (2) The pH of the mixed solution obtained in step (1) is adjusted to 8 by adding ammonia under magnetic stirring.

[0083] (3) Heat and stir the mixed solution in step (2) with pH adjusted to 8 in a constant temperature water bath at 80°C until it becomes a viscous colloid.

[0084] (4) Place the viscous colloid from step (3) into an evaporating dish and heat it in a universal resistance furnace at 200°C for 2 hours to obtain a fluffy black precursor powder.

[0085] (5) Place the fluffy black precursor powder from step (4) into a crucible, and calcine it in an air environment at 1000℃ in a muffle furnace for 5 hours. After natural cooling, obtain La. 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ Cathode material (denoted as LCFN) 0.1 ).

[0086] Example 2

[0087] The only difference from Example 1 is that, while keeping the total molar amount of metal ions constant, the molar ratio of Fe(NO3)3·9H2O(AR) and Ni(NO3)2·6H2O(AR) in the raw materials was modified from 0.9:0.1 to 0.95:0.05, 0.85:0.15, and 0.8:0.2, respectively. This was compared with a treatment group where Ni(NO3)2·6H2O(AR) was omitted and an equal molar amount of Fe(NO3)3·9H2O(AR) was added. The final products were denoted as LCFN. 0.05 LCFN 0.15 LCFN 0.2 、LCFN.

[0088] Comparative Example 1

[0089] The only difference from Example 1 is that the amount of EDTA is modified to 14.3805g (denoted as n(total metal ions):n(CA):n(EDTA)=1:1:1).

[0090] Comparative Example 2

[0091] The only difference from Example 1 is that the amount of EDTA is modified to 28.7609g (denoted as n(total metal ions):n(CA):n(EDTA)=1:1:2).

[0092] Comparative Example 3

[0093] The only difference from Example 1 is that the amount of CA is modified to 5.1703g (denoted as n(total metal ions):n(CA):n(EDTA)=1:0.5:1.5).

[0094] Comparative Example 4

[0095] The only difference from Example 1 is that the amount of CA is modified to 15.5108g (denoted as n(total metal ions):n(CA):n(EDTA)=1:1.5:1.5).

[0096] Example 3

[0097] A symmetrical battery is prepared as follows:

[0098] Weigh 0.5g of samarium oxide-doped cerium oxide (SDC) electrolyte and place it in a circular mold. Press it under 10MPa pressure for 2min to form a circular SDC electrolyte sheet with a diameter of 15mm. Calcinate it in a muffle furnace at 1450℃ for 10h (during which the circular SDC electrolyte sheet is sandwiched between two Al2O3 plates to create a confined space). Allow it to cool naturally to obtain a dense SDC electrolyte sheet.

[0099] The nickel-doped iron-based perovskite material from Examples 1-2 was ball-milled with alcohol for 1 hour and dried in an oven. It was then mixed with terpineol and ethyl cellulose at a mass ratio of 100:94:6 and manually ground until homogeneous to obtain a cathode paste. This cathode paste was then screen-printed onto both sides of the aforementioned SDC electrolyte sheet and baked in an oven at 200°C for 12 hours. Afterward, it was calcined in an air environment at 1000°C for 2 hours and allowed to cool naturally to obtain a symmetrical cell (when the cathode paste contains the product of Example 1, the resulting symmetrical cell is denoted as LCFN). 0.1 |SDC|LCFN 0.1 When LCFN is added 0.05 LCFN 0.15 LCFN 0.2 When LCFN is used, it is denoted as LCFN respectively. 0.05 |SDC|LCFN 0.05 LCFN 0.15 |SDC|LCFN 0.15 LCFN 0.2 |SDC|LCFN 0.2 LCFN (or LCFN-SDC) is used to test the polarization resistance of materials.

[0100] Example 4

[0101] An anode-supported battery is prepared by the following method:

[0102] NiO and SDC were mixed at a mass ratio of 6:4. The resulting NiO-SDC mixed powder was then ball-milled with corn starch at a mass ratio of 4:1 and alcohol for 24 hours to obtain the composite anode material NiO-SDC powder.

[0103] 0.3g of composite anode material NiO-SDC powder was placed in a circular mold and pressed into a disc shape under a pressure of 6MPa for 1 minute without demolding. 0.03g of electrolyte SDC was evenly spread on the disc and pressed onto the top of the anode under a pressure of 10MPa. The double-layer disc was calcined in a muffle furnace at 1450℃ for 5 hours and then naturally cooled to obtain the anode sheet.

[0104] Two g of the cathode paste from Example 3 was screen-printed onto one side of the electrolyte anode sheet. The sample was then baked in an oven at 200°C for 12 hours, followed by calcination in a muffle furnace at 1000°C for 2 hours, and then naturally cooled to obtain an anode-supported cell. (When the cathode paste contains the product from Example 1, the resulting anode-supported cell is denoted as LCFN.) 0.1 |SDC|NiO-SDC; When LCFN is added 0.05 LCFN 0.15 LCFN 0.2 When LCFN is used, it is denoted as LCFN respectively. 0.05 |SDC|NiO-SDC, LCFN 0.15 |SDC|NiO-SDC, LCFN 0.2 |SDC|NiO-SDC, LCFN|SDC|NiO-SDC), are used to test the power density of materials.

[0105] Test Example 1

[0106] The preparation method of the material used for testing electrical conductivity and thermal expansion is as follows:

[0107] Weigh 1.5g of the nickel-doped iron-based perovskite material from Example 1 into a mortar, add 0.03g of polyvinyl butyral (PVB) and 10mL of anhydrous ethanol, and grind thoroughly. After grinding until completely dry, place it in a mold and press it under 10MPa pressure for 2min to form a rectangular strip (29.0mm×6.0mm×0.5mm in size). Then calcine it in a muffle furnace at 1200℃ for 5h and allow it to cool naturally to obtain the material used for testing electrical conductivity and thermal expansion.

[0108] Effect verification

[0109] 1. X-ray diffraction (XRD) characterization

[0110] Figure 1 The XRD patterns are those of the products of Example 1 and Comparative Examples 1-4.

[0111] Figure 1 In the diagram, A, B, C, D, and E represent the products of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively.

[0112] Depend on Figure 1 It can be seen that sample A (Example 1) produced no impurities, which is superior to comparative examples 1-4. Sample B reduced the amount of EDTA (n(total metal ions):n(CA):n(EDTA) = 1:1:1), resulting in an impure sample with NiO impurities. This is because competitive complexation exists between metal ions, leading to incomplete complexation. Sample D reduced the amount of CA (n(total metal ions):n(CA):n(EDTA) = 1:0.5:1.5), resulting in insufficient CA participating in the complexation reaction, leading to incomplete complexation of metal ions and the formation of NiO impurities in the sample.

[0113] Figure 3 The images show the XRD patterns of the products from Examples 1-2 and magnified XRD patterns within the range of 32.0°≤2θ≤33.0°. Wherein, a is the XRD pattern and b is the magnified XRD pattern within the range of 32.0°≤2θ≤33.0°.

[0114] Depend on Figure 3 It can be seen that these materials have a single perovskite structure, and no impurity peaks were detected. (From La...) 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The magnified XRD spectrum in the range of 32.0°≤2θ≤33.0° shows that, compared to La 0.6 Ca 0.4 FeO 3-δ (LCFN), Ni doping shifts the (110) diffraction peak of perovskite towards a larger angle because... Oxidized to It also partially replaced This also indicates that Ni was successfully doped into La. 0.6 Ca 0.4 FeO 3-δ Crystal lattice.

[0115] Figure 4 For LCFN 0.1 |SDC||LCFN 0.1 XRD pattern.

[0116] Figure 4 In the middle, only La can be observed 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ (LCFN 0.1 The diffraction peaks of LCFN and SDC were observed, and no other obvious multi-peaks were detected, indicating that LCFN... 0.1 There is no chemical reaction between it and SDC, and it has good chemical compatibility.

[0117] 2. Characterization by scanning electron microscopy (SEM)

[0118] Figure 2 The images shown are SEM images of the products of Example 1 and Comparative Examples 1-4. Specifically, a, b, c, d, and e are SEM images of the products of Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4, respectively.

[0119] Depend on Figure 2 It can be seen that the product of Example 1 has a smaller particle size and a certain porosity, while other control experiments all showed varying degrees of coarsening. Comparative Example 2 increased the amount of EDTA (n(total metal ions):n(CA):n(EDTA) = 1:1:2), which ensured sufficient complexation but caused new problems: the sample showed particle coarsening, and the raw material cost also increased significantly. Comparative Example 4 increased the amount of CA (n(total metal ions):n(CA):n(EDTA) = 1:1.5:1.5). During high-temperature heat treatment, a large amount of residual CA decomposed to produce gas, which easily formed large pores inside the material, causing O2 to escape without sufficient reaction, reducing gas utilization. At the same time, the effective reaction area around the large pores decreased sharply, resulting in a decrease in oxygen reduction reaction activity.

[0120] Figure 5 a, b, c, d, and e represent LCFN|SDC and LCFN, respectively. 0.05 |SDC、LCFN 0.1 |SDC、LCFN 0.15 |SDC、LCFN 0.2 SEM image of the cross section of SDC, where f is the LCFN. 0.1 SEM image of the cross section of |SDC|NiO-SDC.

[0121] Depend on Figure 5 It can be seen that La 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The cathode material adhered tightly to the SDC electrolyte, with no obvious cracks observed at the interface, and the SDC electrolyte sheet was dense. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The material has a porous microstructure, which is a necessary condition for high electrode porosity and is conducive to oxygen diffusion, surface oxygen exchange and charge conduction.

[0122] 3. Transmission electron microscopy (TEM) characterization

[0123] Figure 6The images show the HR-TEM image and corresponding Fast Fourier Transform (FFT) pattern of the product in Example 1, as well as the spectral outlines of the selected area electron diffraction (SAED) lattice fringes. Wherein, a, c, and d are the HR-TEM image of the product on the d(110) crystal plane, the FFT pattern marked in a, and the spectral outlines of the SAED lattice fringes, respectively; b, e, and f are the HR-TEM image of the product on the d(100) crystal plane, the FFT pattern marked in b, and the spectral outlines of the SAED lattice fringes, respectively.

[0124] Depend on Figure 6 It can be observed that a lattice fringe spacing of 0.383 nm corresponds to the (100) crystal plane of perovskite, and a lattice fringe spacing of 0.272 nm corresponds to the (110) crystal plane of perovskite.

[0125] 4. TEM energy dispersive spectroscopy characterization

[0126] Figure 7 The images show the STEM and EDS elemental distributions of the product from Example 1. In the images, a is the STEM image, and b, c, d, e, and f are the EDS elemental distributions.

[0127] Depend on Figure 7 It can be seen that La 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ Ni was successfully doped into the sample, with La, Ca, Fe, Ni and O elements evenly distributed and no obvious elemental segregation.

[0128] 5. X-ray photoelectron spectroscopy characterization

[0129] Figure 8 The O1s spectra of the products from Examples 1-2 are shown.

[0130] Figure 8 Including adsorbed oxygen (O) ads ), lattice oxygen (O) lat ), vacancy oxygen (O) vac ), water and oxygen (O) moi Because O ads At high temperatures, it easily desorbs to form oxygen vacancies, therefore, O ads +O vac / O lat The ratio typically represents the oxygen vacancy concentration, which directly affects electrochemical performance and stability. As the Ni doping concentration increases, the oxygen vacancy rate increases. ads +O vac / O lat The ratios gradually increased, becoming 1.41, 1.58, 1.74, 1.79, and 1.96 respectively.

[0131] 6. Thermal expansion test

[0132] Figure 9 The graph shows the thermal expansion of the products from Examples 1-2 at temperatures ranging from room temperature to 750°C.

[0133] For the long-term stability of SOFC performance, the thermal expansion compatibility between the cathode material and the electrolyte is a key issue. Typically, adjacent components need to have similar thermal expansion behavior to minimize thermal stress and cracking, thereby extending the SOFC's lifespan.

[0134] Figure 9 In the middle, La 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The thermal expansion of La is significantly lower than that of some common Co-based and Fe-based materials. 0.6 Ca 0.4 FeO 3-δ The TEC of the matrix material is 15.38 × 10⁻⁶. -6 K -1 La 0.6 Ca 0.4 Fe 0.8 Ni 0.2 O 3-δ The TEC is 13.61 × 10⁻⁶. -6 K -1 It is evident that the gradual doping of Ni significantly suppresses the thermal expansion behavior of the material, which helps to achieve matching with commonly used electrolytes (TECs), thereby improving the structural integrity and service life of the battery.

[0135] 7. Rectangular strip conductivity test

[0136] Figure 10 The graph shows the temperature variation of conductivity of the products from Examples 1-2 measured at 400-800°C.

[0137] Figure 10 In this process, the conductivity increases with increasing temperature, exhibiting semiconductor behavior. The carrier concentration and mobility increase with increasing temperature, leading to the increase in conductivity. It reaches a maximum at 500℃, after which the conductivity decreases with further increases in temperature, exhibiting metallic-like behavior. To maintain charge neutrality, some Fe... 4+ Reduced to low-valence Fe 3+ Furthermore, at high temperatures, lattice vibration scattering is enhanced, and carrier mobility decreases. Simultaneously, at high temperatures, lattice oxygen is released, forming oxygen vacancies. The formation of additional oxygen vacancies and the reduced carrier mobility at higher temperatures are detrimental to electron-hole transport, leading to a decrease in conductivity. With increasing Ni doping concentration, La... 0.6 Ca 0.4 Fe1-x Ni x O 3-δ The electrical conductivity of the material gradually increases, La 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ It reaches its maximum value (328.5 S·cm) at 500℃. -1 This is mainly because, by doping low-valence Ni ions at the B site, this invention leads to Fe... 3+ Oxidized to Fe 4+ To maintain La 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Ni achieves electron neutrality, leading to the formation of oxygen vacancies and thus increasing conductivity. However, this does not mean that more Ni doping is more conducive to electron-hole transport; excessive oxygen vacancies reduce electron-hole migration. When Ni doping is 0.2%, the conductivity is significantly lower than that of undoped La. 0.6 Ca 0.4 FeO 3-δ .

[0138] 8. Electrochemical Impedance Testing of Symmetrical Cells

[0139] Figure 11 The figures show the electrochemical impedance spectroscopy (EIS) and Arrhenius plot of the polarization impedance as a function of temperature for the product of Example 3, measured at 600-800°C. In the figures, a, b, c, d, and e are electrochemical impedance spectroscopy, and f is an Arrhenius plot.

[0140] Figure 11 In the middle, LCFN, LCFN 0.05 LCFN 0.1 LCFN 0.15 LCFN 0.2 Representing LCFN|SDC|LCFN, LCFN respectively 0.05 |SDC|LCFN 0.05 LCFN 0.1 |SDC|LCFN 0.1 LCFN 0.15 |SDC|LCFN 0.15 LCFN 0.2 |SDC|LCFN 0.2 .

[0141] Depend on Figure 11 It can be seen that Ni doping reduces the Rp of the material, from 0.16 Ω·cm at 800℃. 2 (La 0.6 Ca0.4 FeO 3-δ The value decreased to 0.097 Ω·cm 2 (La 0.6 Ca 0.4 Fe 0.9 Ni 0.1 O 3-δ This improved the electrochemical performance of the battery. With increasing Ni doping concentration, Rp initially decreased and then increased. This is because excessive doping may lead to oxygen vacancy localization, hindering oxygen ion migration. Based on the slope of the Arrhenius curve, La was calculated. 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ The activation energies are 1.188 eV, 1.137 eV, 0.966 eV, 0.952 eV, and 0.955 eV, respectively. Among them, La... 0.6 Ca 0.4 Fe 0.85 Ni 0.15 O 3-δ It has the lowest activation energy.

[0142] 9. Power density test of anode-supported battery

[0143] Figure 12 The graph shows the current density-voltage-power density (IVP) curves of the product of Example 4 measured at 600-800°C.

[0144] Where a is LCFN|SDC|NiO-SDC, and b is LCFN 0.1 |SDC|NiO-SDC.

[0145] Figure 12 In, with undoped La 0.6 Ca 0.4 FeO 3-δ Compared to (LCFN|SDC|NiO-SDC), when Ni is doped to 0.1% (Example 1), the PPD reaches 674.62 mW·cm⁻¹ at 800°C. -2 Compared to the matrix, PPD increased by 73.61%.

[0146] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A nickel-doped iron-based perovskite material for preparing B-site doped cathodes of solid oxide fuel cells, characterized in that, The chemical formula is La 0.6 Ca 0.4 Fe 1-x Ni x O 3-δ Where x takes the values ​​0.1 and 0.2 < δ ≤ 0.3; The preparation method of the nickel-doped B-site iron-based perovskite material includes the following steps: Lanthanum salt, calcium salt, iron salt and nickel salt are dissolved in water to obtain a metal ion solution; ethylenediaminetetraacetic acid is dissolved in a solvent, and then mixed with the metal ion solution and citric acid, and the pH value is adjusted to alkaline to obtain a precursor solution; The precursor liquid was heated and stirred at 80 °C until it became a viscous colloid, and then the solvent was evaporated to remove the precursor powder. The powder was then calcined to obtain the nickel-doped iron-based perovskite material at the B site. The lanthanum salt is La(NO3)3; the calcium salt is Ca(NO3)2; the iron salt is Fe(NO3)3; the nickel salt is Ni(NO3)2; the total molar amount of the iron salt and nickel salt is in the molar ratio of the lanthanum salt and calcium salt to 10:6:4, and the ratio of the molar amount of the nickel salt to the sum of the molar amounts of the iron salt and nickel salt is 0-0.2 and not 0; The total molar amount of metal ions in the metal ion solution, in molar ratio to citric acid and ethylenediaminetetraacetic acid, is 0.9-1.1:0.9-1.1:1.4-1.

6. The pH value is 8.

2. The iron-based perovskite material according to claim 1, characterized in that, The method for removing solvent by evaporation includes the following steps: heating at 200 °C for 2 h to obtain a fluffy, black precursor powder.

3. The iron-based perovskite material according to claim 1, characterized in that, The calcination treatment is carried out at a temperature of 1000°C for 5 hours; and / or the calcination treatment is carried out in an air atmosphere.

4. The application of the B-site-doped nickel iron-based perovskite material according to any one of claims 1-3 in the field of solid oxide fuel cell cathode materials.

5. A solid oxide fuel cell, characterized in that, The cathode material of the solid oxide fuel cell includes the B-site-doped nickel iron-based perovskite material as described in any one of claims 1-3.

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