CN114420943A - Heterogeneous interface composite electrode material and preparation method and application thereof - Google Patents

Abstract

The invention relates to an in-situ preparation method and application of a composite electrode material. The chemical formula of the composite electrode material is La _1‑x Sr _{x+ a} Fe _1‑y‑z N _y M _z O _3‑δ , wherein N is selected from Cu , one or more of Ni or Co, M is selected from one of Ti, Nb or Mo, 0.3≤x≤0.8, 0<y≤0.3, 0<z≤0.2, ‑0.5<δ<0.5 , 0<a≤0.2. The preparation method is as follows: in the feeding stage of preparing the ABO ₃ (SP) type perovskite oxide La _1‑x Sr _x Fe _1‑y‑z N _y M _z O _3‑δ , additionally adding a Sr-containing compound, wherein the Sr The molar amount is 0-0.2 times the total molar amount of La and Sr in the ABO ₃ -type perovskite oxide, but not 0. After high temperature calcination, a small amount of Ruddlesden-Popper (RP) layered perovskite phase (A _n+1 B _n O _3n+1 , n=1-3) is formed, thereby forming the SP-RP composite electrode material. Compared with the corresponding single-phase perovskite symmetrical electrode material, the composite electrode material of the invention can not only improve the performance of the oxygen electrode, improve the thermal expansion matching between the electrode and the electrolyte, but also significantly improve the performance of the oxygen electrode. The electrocatalytic activity, electrical conductivity and stability of the fuel electrode significantly simplify the preparation process and are easy to scale up.

Description

Heterogeneous interface composite electrode material, preparation method and application thereof

technical field

The invention belongs to the technical field of electrode materials and oxygen-permeable membranes, and relates to a heterogeneous interface composite electrode material and a preparation method and application thereof.

Background technique

A solid oxide fuel cell (SOFC) is a device that converts chemical energy into electrical energy, and has the advantages of all-solid-state, high energy conversion efficiency, fuel diversity, and environmental friendliness. Its reverse operation is the electrolysis cell (SOEC), which can use renewable energy to electrolyze water, CO ₂ , hydrocarbons or co-electrolyte water-CO ₂ , CO ₂ -hydrocarbons to produce hydrogen and value-added chemicals, thereby disposing of waste. / Idle electrical energy is converted into chemicals for energy storage. SOFC and SOEC are two working modes of the same device, which can realize the clean conversion of fossil energy into electricity and renewable energy storage at the same time. The electrodes (oxygen electrode and fuel electrode) determine SOFC and SOEC single cell performance and stability. Therefore, improving the electrochemical catalytic activity and durability of electrodes is an important way to promote the commercial application of SOFC/SOEC technology. The symmetrical structure single cell can significantly simplify the battery structure and preparation process, reduce the battery preparation cost and energy consumption, improve the thermal expansion matching between the battery components, and improve the battery's anti-sulfur and anti-carbon performance, thereby improving the stability and reliability of battery operation.

Although ABO ₃ (SP) type perovskite oxides have the advantages of high electrical conductivity and good oxygen reduction catalytic performance, during long-term high-temperature operation, A-site cations such as Sr ²⁺ , Ba ²⁺ , Pb ²⁺ , etc. Surface segregation occurs, forming non-conductive oxide particles, reducing the electrical conductivity and surface oxygen exchange rate of the electrode, resulting in the degradation of single cell performance and stability over time. For example, Sr ²⁺ segregation on the electrode surface will form SrO nanoparticles, while SrO Non-conductive, it will hinder the transfer of electrons, thereby seriously reducing the electrode reaction rate. Meanwhile, ABO ₃ (SP)-type perovskite oxides generally exhibit a higher thermal expansion coefficient, which is comparable to the thermal expansion of common electrolyte materials such as zirconia-based electrolytes (YSZ, ScSZ, etc.), ceria-based electrolytes (GDC, SDC, etc.) Unmatched, resulting in delamination and cracking between the electrode and the electrolyte when the battery is operated at high temperature for a long time, thereby compromising the stability and durability of the battery.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a heterogeneous interface composite electrode material and its preparation method and application, which solve the problems of insufficient electrochemical performance and stability of the electrode material in SOFC/SOEC. The electrode material can also be used as oxygen permeable membrane material for membrane electrode separation or membrane electrode reactor.

The object of the present invention can be realized through the following technical solutions:

A heterogeneous interface composite electrode material, the chemical formula of the composite electrode material is La _1-x Sr _x+a Fe _{1-y- z} N _y M _z O _3-δ , wherein, N is selected from Cu, Ni or Co One or more of , M is selected from one of Ti, Nb or Mo, 0.3≤x≤0.8, 0<y≤0.3, 0<z≤0.2, -0.5<δ<0.5, 0<a≤ 0.2.

A preparation method of a heterointerface composite electrode material, the method comprises the following steps: in the feeding stage of preparing ABO ₃ type perovskite oxide La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , additionally adding The Sr-containing compound, and the molar amount of Sr in the additionally added Sr-containing compound is 0-0.2 times, but not 0, of the total molar amount of La and Sr in the ABO ₃ -type perovskite oxide.

Further, the Sr-containing compound includes one or more of Sr(NO ₃ ) ₂ , SrCO ₃ , SrO or SrCl ₂ .

Further, ABO ₃ type perovskite oxides were prepared by co-precipitation method, solid phase method or sol-gel method.

Further, the co-precipitation method is: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , La ³⁺ salt, Sr ²⁺ salt, Fe ³⁺ salt, N ⁿ⁺ The salt and M ^m+ salt are mixed and dissolved in nitric acid to obtain a nitrate solution, and Sr(NO ₃ ) ₂ is additionally added, and then wet-chemical co-precipitation is carried out with a precipitant to obtain a composite electrode material precursor, which is calcined at high temperature. The heterogeneous interface composite electrode material is obtained. During the co-precipitation process, the molar ratio of the metal ion mother liquor and the precipitant ammonium bicarbonate was 1:4.

Further, the solid phase method is: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , lanthanum oxide, strontium oxide, iron oxide, N oxide, M oxide are oxidized mixed with ethanol, SrO is added additionally, and the composite electrode material precursor is obtained after ball milling for 6-12 hours.

Further, the sol-gel method is: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , lanthanum nitrate, strontium nitrate, ferric nitrate, N ⁿ⁺ nitrate, The nitrate of M ^m+ was mixed and dissolved in water, and SrCl ₂ was additionally added, and then ethylenediaminetetraacetic acid (EDTA) and citric acid (CA) were added to prepare a gel, which was heated and carbonized (250°C) to obtain a composite electrode The material precursor is then calcined at high temperature to obtain the heterogeneous interface composite electrode material. The gel preparation process is as follows: heating at 80°C to complete the reaction, and then evaporating to obtain a gel.

Further, the high temperature calcination temperature is 700-1200°C, and the high temperature calcination time is 5-20h. After high temperature calcination, ABO ₃ (SP) type perovskite and Sr-containing compound generate a small amount of Ruddlesden-Popper (RP) type layered perovskite phase (A _{n+ 1} B _n O _3n+1 , n=1-3), forming SP-RP composite electrode material.

An application of a heterogeneous interface composite electrode material, the composite electrode material is applied in SOFC/SOEC, oxygen permeable membrane, membrane electrode separation and membrane electrode reactor.

Further, in application, the composite electrode material is used for SOFC/SOEC symmetrical electrode, oxygen electrode or fuel electrode. Both porous electrodes and dense electrodes can be prepared.

Studies have shown that the Ruddlesden-Popper (RP) type layered perovskite phase (A _n+1 B _n O _3n+1 , n=1-3) type layered perovskite has a high oxygen ion surface exchange rate and Due to the low thermal expansion coefficient, Sr-containing compounds are added to in situ generate RP-type layered perovskite oxides on the surface of ABO ₃ (SP) perovskite, and the two form a RP/SP hetero interface, which can effectively improve the ABO ₃ (SP) perovskite surface. Electron and ion exchange kinetics on the surface of the SP electrode, improve the thermal expansion matching between the electrode and the electrolyte, and significantly improve the performance and stability of the electrode. However, the RP/SP heterostructure is very sensitive to the spatial size and two-phase distribution, and the RP phase oxide is anisotropic. When the thickness of the RP phase is too large and/or the distribution density is too high, it not only cannot improve the electrode reaction kinetics, but also It can also impair electrode performance and stability. Pulsed laser deposition (PLD) can be used to fabricate microscopic electrodes with RP/SP heterostructures, but this method is expensive and time-consuming, making it difficult for macroscopic porous electrodes to be fabricated and industrialized. In addition, the solution impregnation method is cumbersome to prepare, and it is difficult to control the size and distribution of the RP phase; the particles of the RP phase in the RP/SP composite prepared by the sol-gel-co-growth method are larger than those of the SP phase, and tend to grow longer with time. into a larger particle size, resulting in a decrease in the conductivity and stability of the electrode.

In the present invention, when the ABO ₃ -type perovskite oxide La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ is synthesized by a conventional method, a small amount of Sr-containing compound is additionally added in the feeding stage, and the Sr-containing compound is mixed with The perovskite main phase forms a small amount of RP-type layered perovskite through element migration, and in-situ self-assembles with the perovskite main phase to form a heterogeneous composite perovskite electrode material containing a heterogeneous interface. Take an appropriate amount of electrode material powder and mix it with pore-forming agent, binder (all kinds of organic or inorganic binders) and other ball mills to obtain a composite electrode slurry, and coat it (spraying method, spin coating method or screen printing method, etc.) to The electrolyte surface, after high temperature sintering, is the SOFC/SOEC composite electrode. The above-mentioned multiphase composite electrode materials can form metal/oxide, layered perovskite RP/perovskite SP oxide multiple heterointerfaces by in-situ precipitation of metal nanoparticles in a reducing atmosphere, which can significantly improve the conductivity of fuel electrodes. and electrocatalytic activity, thereby improving the output power and stability of the single cell.

Compared with the prior art, the present invention has the following characteristics:

1) The heterointerface composite electrode material in the present invention has the characteristic of mixed conductance of electrons and ions, and can conduct oxygen ions and electrons. The in-situ formed second phase self-assembles with the perovskite main phase to form a heterointerface, which improves the surface oxygen exchange coefficient of the material and improves the performance of the oxygen electrode. After reduction and precipitation of metal nanoparticles, the electrocatalytic activity, electrical conductivity and stability of the fuel electrode are significantly improved, the polarization impedance is extremely low at 600-1000 °C, and the output power is high.

2) In the present invention, a multiphase composite electrode material containing a heterogeneous interface is synthesized in-situ by one-step self-assembly. Compared with the corresponding single-phase perovskite symmetrical electrode material, the composite electrode material can be used as oxygen electrode and fuel electrode at the same time, and has dual functions of cathode and anode. The electrocatalytic activity, electrical conductivity and stability of the fuel electrode are significantly improved, and the one-step in-situ preparation can significantly simplify the preparation process and be easy to scale up.

Description of drawings

FIG. 1 is the XRD pattern of the electrode material La _0.6 Sr _0.4+a Ni _0.15 Fe _0.75 Nb _0.1 O _3-δ (x=0, 0.1, 0.2) prepared by one-step self-assembly in the example after calcining in air for 10h.

Fig. 2 shows the electrode material La _0.6 Sr _0.4+0.1 Cu _0.1 Fe _0.8 Ti _0.1 O _3-δ prepared by one-step self-assembly in the example, after n times (n=0, 1, 2, 3) calcination in air for 10h oxidation And the XRD pattern after calcination in hydrogen-argon atmosphere for 10h and reduction.

3 is a TEM image of the electrode material La _0.5 Sr _0.5+0.1 Cu _0.15 Fe _0.8 Mo _0.05 O _3-δ prepared by one-step self-assembly in the example after calcination in air for 10 h.

Fig. 4 shows the electrode material La _0.6 Sr _0.4+0.1 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ and the SP-type perovskite electrode material La _0.6 Sr _0.4 Fe _0.8 Cu _0.15 Ti _0.05 O ₃ prepared by one-step self-assembly in the embodiment -Comparison of _symmetric single cell power density for 100h at 800°C in a hydrogen-argon atmosphere.

Figure 5 shows the single-cell performance of the RP/SP composite electrode material La _0.6 Sr _{0.4+ 0.1} Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ prepared by one-step self-assembly in the example in the range of 700-900 ℃ in a hydrogen-argon atmosphere Graph.

Figure 6 shows the RP/SP composite electrode material La _0.6 Sr _{0.4+ 0.1} Fe _0.8 Co _0.1 Nb _0.1 O _3-δ and the SP-type perovskite electrode material La _0.6 Sr _0.4 Fe _0.8 Co _0.1 prepared by one-step self-assembly in the example The curve of thermal expansion coefficient of Nb _0.1 O _3-δ .

Detailed ways

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented on the premise of the technical solution of the present invention, and provides a detailed implementation manner and a specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

The invention provides a heterogeneous interface composite electrode material, the chemical formula of the composite electrode material is La _1-x Sr _{x+ a} Fe _1-yz N _y M _z O _3-δ , wherein, N is selected from Cu, Ni or Co One or more of, M is selected from one of Ti, Nb or Mo, 0.3≤x≤0.8, 0<y≤0.3, 0<z≤0.2, -0.5<δ<0.5, 0<a ≤0.2.

The present invention also provides a method for preparing the above-mentioned hetero-interface composite electrode material. The method is as follows: when preparing the ABO ₃ type perovskite oxide La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ In the first stage, the Sr-containing compound is additionally added, and the molar amount of Sr in the additionally added Sr-containing compound is 0-0.2 times, but not 0, the total molar amount of La and Sr in the ABO ₃ -type perovskite oxide.

Wherein, the Sr-containing compound includes one or more of Sr(NO ₃ ) ₂ , SrCO ₃ , SrO or SrCl ₂ . ABO ₃ -type perovskite oxides were prepared by co-precipitation, solid-phase or sol-gel methods.

The co-precipitation method is specifically as follows: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , La ³⁺ salt, Sr ²⁺ salt, Fe ³⁺ salt, N ⁿ⁺ salt, M ^m+ salt is mixed and dissolved in nitric acid to obtain a nitrate solution, and Sr(NO ₃ ) ₂ is additionally added, and then wet-chemical co-precipitation is carried out with a precipitant to obtain a composite electrode material precursor, which is calcined at high temperature. Interfacial composite electrode material.

The solid phase method is specifically as follows: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , lanthanum oxide, strontium oxide, iron oxide, N oxide, M oxide, Ethanol is mixed, SrO is additionally added, and the composite electrode material precursor is obtained after ball milling, and then the heterogeneous interface composite electrode material is obtained by pressing and calcining at high temperature.

The sol-gel method is specifically as follows: according to the stoichiometric ratio of La _1-x Sr _x Fe _1-yz N _y M _z O _3-δ , lanthanum nitrate, strontium nitrate, iron nitrate, nitrate of N ⁿ⁺ , M ^m+ mixed with the nitrates and dissolved in water, and then additionally added SrCl ₂ , then EDTA and citric acid were added to prepare a gel, which was heated and carbonized to obtain the composite electrode material precursor, and then calcined at high temperature to obtain heterogeneous Interface composite electrode material.

The high temperature calcination temperature is 700-1200°C, and the high temperature calcination time is 5-20h.

The invention also provides the application of the above-mentioned hetero-interface composite electrode material. The composite electrode material is applied in SOFC/SOEC, and can be used for SOFC/SOEC symmetrical electrode, oxygen electrode or fuel electrode.

In the composite electrode material of the present invention, the multi-phase composite electrode material is prepared by one-step in-situ self-assembly by adjusting the ratio of Sr in the initial charging ratio. The formation of a structurally stable RP phase effectively suppresses the segregation of Sr and improves the Electrocatalytic activity and stability of electrodes. Symmetric single cell ( _LSr0.5FCT /SDC/ _ScSZ / _{SDC / LSr0.5FCT} /SDC/ _ScSZ /SDC/ _LSr0 . 5FCT), compared with the symmetric single cell prepared by the perovskite SP-type electrode material La _0.6 Sr _0.4 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ (LSr0.4FCT), the power density of LSr0.5FCT at 800 °C can reach 450mW·cm ^-2 and increased to 460mW·cm ^-2 after 100h of operation. However, the power density of the LSr0.4FCT symmetrical single cell at 800℃ is only 430mW·cm ^-2 , and it decays to 370mW·cm ^-2 after running for 100h.

Example 1:

Preparation of La _0.6 Sr _0.4+0.2 Ni _0.15 Fe _0.75 Nb _0.1 O _3-δ Composite Electrode Materials

Weigh 6.98g La ₂ O ₃ , 6.21g SrO, 1.11g NiO, 0.66g Nb ₂ O ₅ , 5.99g Fe ₂ O ₃ at 400℃-1000℃ for 10h pretreatment, add a small amount of anhydrous ethanol, use 350r /min speed ball milling for 24h; then dried at 120℃ for 24h to obtain La _0.6 Sr _0.4+0.2 Ni _0.15 Fe _0.75 Nb _0.1 O _3-δ electrode material precursor powder, and then pressed under 4Mpa pressure for 10min into tablets, and then put It was calcined in a muffle furnace, the calcination temperature was 1100 °C, and the calcination time was 10 h, and finally La _0.6 Sr _{0.4+ 0.2} Ni _0.15 Fe _0.75 Nb _0.1 O _3-δ composite electrode material was obtained. The XRD results of the powder are shown in Figure 1. It can be seen that when x>0, the structure will form a small amount of RP phase in the main perovskite phase, that is, the existence of SP and RP two phases in the electrode material prepared by one-step self-assembly.

Example 2:

Preparation of La _0.6 Sr _0.4+0.1 Cu _0.1 Fe _0.8 Ti _0.1 O _3-δ Composite Electrode Materials

Weigh a certain amount of EDTA and CA, dissolve them in a small amount of water and adjust the pH to 8 with ammonia water, then weigh 21.65g La(NO ₃ ) ₃ ·6H ₂ O, 12.71g Sr(NO ₃ ) ₂ , 2.45g Cu(NO ₃ ) ₂ ·6H ₂ O, 32.32g Fe(NO ₃ ) ₃ ·9H ₂ O, 2.99g Ti(NO ₃ ) ₄ were dissolved in water, then slowly added to the EDTA-CA mixed solution, and the pH was adjusted again to 8. Heat in a water bath to evaporate the water until a gel is formed. The gel was heated at 250°C for 5h, carbonized to obtain electrode material precursor, and then calcined at 900°C for 10h to finally obtain La _0.6 Sr _0.4+0.1 Cu _0.1 Fe _0.8 Ti _0.1 O _3-δ composite electrode material nanopowder. Figure 2 shows the XRD results of the redox cycle of the powder undergoing n times (n=0, 1, 2, 3) calcination in air for 10h oxidation and calcination in hydrogen-argon atmosphere for 10h reduction. The XRD spectra of three redox cycles of LSCFT prove that the material can still restore the original perovskite structure after repeated reduction and oxidation cycles, and no impurities are formed, which proves the good redox reversibility of the material.

Example 3:

Preparation of La _0.5 Sr _0.5+0.1 Cu _0.15 Fe _0.8 Mo _0.05 O _3-δ Composite Electrode Materials

Weigh 21.65g La(NO ₃ ) ₃ ·6H ₂ O, 12.71g Sr(NO ₃ ) ₂ , 2.47g Cu(NO ₃ ) ₂ , 2.13gMo(NO ₃ ) ₃ ·5H ₂ O, 28.28g Fe(NO ₃ ) ₃ 9H ₂ O, dissolved in water to obtain a nitrate solution, using ammonium bicarbonate as a precipitant, mixed with wet chemical co-precipitation and reverse drop method to obtain electrode material precursor, calcined at 1000 ℃ for 10h, to obtain La _0.5 Sr _{0.5 + 0.1} Cu _0.15 Fe _0.8 Mo _0.05 O _3-δ composite electrode nano-powder, the TEM results of the powder are shown in Figure 3, which proves that La _0.5 Sr _0.5 Cu _0.15 Fe _0.8 Mo _0.05 O _3-δ (SP), Two phases of LaSrCu _0.15 Fe _0.8 Mo _0.05 O _4-δ (RP) coexist.

Example 4:

La _0.6 Sr _0.4+0.1 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ composite electrode material nano-powder was prepared according to the above method, and was mixed with terpineol and polymethyl methacrylate in a mass ratio of 2:1.4:0.3 After mixing and ball milling, electrode slurry is obtained, and the electrode slurry is evenly coated on the SSZ electrolyte sheet (SDC/SSZ/SDC) coated with an SDC buffer layer on both sides to obtain the corresponding symmetrical single cell. The single cell performance curve of the La _0.6 Sr _0.4+0.1 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ symmetrical full cell in a hydrogen-argon atmosphere in the range of 700-900°C was measured. The results are shown in Figure 5. The power density at 800 °C of the symmetric single cell with the phase perovskite La _0.6 Sr _0.4 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ and the conventional electrode LSCM as the electrode is much lower than that of the above-mentioned composite electrode.

The power density of a symmetric single cell based on La _0.6 Sr _0.4+0.1 Fe _0.8 Cu _0.15 Ti _0.05 O _3-δ operating at 800 °C and 0.7 V for 100 h was compared with that of the SP-type perovskite electrode material La _0.6 Sr _0.4 Fe _0.8 Cu The power density comparison of _0.15 Ti _0.05 O _3-δ , the results are shown in Figure 4, which proves that the composite electrode material prepared by one-step self-assembly improves the output stability of the symmetrical single cell.

Example 5:

La _0.6 Sr _0.4+0.1 Fe _0.8 Co _0.1 Nb _0.1 O _3-δ composite electrode material nano-powders were prepared according to the above method, and were made into splines by hydraulic pressure at 5 Mpa for 10 minutes. The thermal expansion coefficient of the spline was measured using a thermal dilatometer and compared with the SP-type perovskite La _0.6 Sr _0.4 Fe _0.8 Co _0.1 Nb _0.1 O _3-δ . The composite samples prepared by self-assembly method can significantly reduce the thermal expansion coefficient.

The foregoing description of the embodiments is provided to facilitate understanding and use of the invention by those of ordinary skill in the art. It will be apparent to those skilled in the art that various modifications to these embodiments can be readily made, and the generic principles described herein can be applied to other embodiments without inventive step. Therefore, the present invention is not limited to the above-mentioned embodiments, and improvements and modifications made by those skilled in the art according to the disclosure of the present invention without departing from the scope of the present invention should all fall within the protection scope of the present invention.

Claims (10)

1. A heterogeneous interface composite electrode material is characterized in that the chemical formula of the composite electrode material is La_1-xSr_{x+ a}Fe_1-y-zN_yM_zO_3-δWherein N is selected from one or more of Cu, Ni or Co, M is selected from one of Ti, Nb or Mo, x is more than or equal to 0.3 and less than or equal to 0.8, and 0 is less than or equal to 0<y≤0.3，0<z≤0.2，-0.5<δ<0.5，0<a≤0.2。

2. A method of preparing the heterointerface composite electrode material of claim 1, the method comprising: in the preparation of ABO₃Perovskite oxide La_1-xSr_xFe_1-y-zN_yM_zO_3-δThe charging stage of (a), an additional Sr-containing compound is added, and the molar weight of Sr in the additional Sr-containing compound is ABO₃The perovskite oxide has a molar amount of La to Sr of 0-0.2 times but not 0.

3. The method as claimed in claim 2, wherein the Sr-containing compound comprises Sr (NO)₃)₂、SrCO₃SrO or SrCl₂One or more of.

4. The method for preparing the heterointerface composite electrode material according to claim 2, wherein the ABO is prepared by a coprecipitation method, a solid phase method or a sol-gel method₃A perovskite-type oxide.

5. The method for preparing the heterointerface composite electrode material according to claim 4, wherein the method comprises the following steps: according to La_1-xSr_xFe_1-y-zN_yM_zO_3-δStoichiometric ratio of La³⁺Salt, Sr²⁺Salt, Fe³⁺Salt, Nⁿ⁺Salt, M^m+The salts are mixed and dissolved in nitric acid to obtain a nitrate solution, and then additional Sr (NO) is added₃)₂And then carrying out wet chemical coprecipitation and back dripping by using a precipitator to obtain a composite electrode material precursor, and calcining at high temperature to obtain the heterogeneous interface composite electrode material.

6. The method for preparing the heterointerface composite electrode material according to claim 4, wherein the method comprises the following steps: according to La_1-xSr_xFe_1-y-zN_yM_zO_3-δMixing lanthanum oxide, strontium oxide, iron oxide, N oxide, M oxide and ethanol, adding SrO additionally, performing ball milling to obtain a composite electrode material precursor, tabletting, and calcining at high temperature to obtain the heterogeneous interface composite electrode material.

7. The method for preparing the heterointerface composite electrode material according to claim 4, wherein the method comprises the following steps: according to La_1-xSr_xFe_1-y-zN_yM_zO_3-δThe stoichiometric ratio of lanthanum nitrate, strontium nitrate, ferric nitrate and Nⁿ⁺Nitrate salt of (A), M^m+Mixed with nitrate and dissolved in water, and additional SrCl is added₂And then adding ethylene diamine tetraacetic acid and citric acid to prepare gel, heating and carbonizing to obtain a composite electrode material precursor, and calcining at high temperature to obtain the heterogeneous interface composite electrode material.

8. The method as claimed in any one of claims 5 to 7, wherein the high temperature calcination temperature is 700-1200 ℃ and the high temperature calcination time is 5-20 h.

9. Use of the heterointerface composite electrode material according to claim 1 in SOFC/SOEC, oxygen permeable membrane, membrane electrode separation and membrane electrode reactor.

10. Use of a heterointerface composite electrode material according to claim 9, wherein said composite electrode material is used in SOFC/SOEC symmetric electrodes, oxygen electrodes or fuel electrodes.

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