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, wherein 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 is less than or equal to 0.2. The preparation method comprises the following steps: in the preparation of ABO₃(SP) type perovskite oxide La_1‑xSr_xFe_1‑y‑zN_yM_zO_3‑δIn the charging stage, an Sr-containing compound is additionally added, wherein the molar weight of Sr is ABO₃The perovskite oxide has a molar amount of La to Sr of 0-0.2 times but not 0. High-temperature calcination to form a small amount of Ruddlesden-popper (RP) -type lamellar perovskite phase (A)_n+1B_nO_3n+1N is 1-3), therebyForming the SP-RP composite electrode material. The composite electrode material can be used as an oxygen electrode and a fuel electrode at the same time, and compared with the corresponding single-phase perovskite symmetrical electrode material, the composite electrode material not only improves the performance of the oxygen electrode and the thermal expansion matching between the electrode and an electrolyte, but also obviously improves the electrocatalytic activity, the conductivity and the stability of the fuel electrode, obviously simplifies the preparation process and is easy to amplify.

Description

Heterogeneous interface composite electrode material and 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

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, environmental friendliness, and the like. The reverse operation mode is electrolytic cell (SOEC), and water and CO can be electrolyzed by using renewable energy₂Hydrocarbon or CO-electrolyzed water-CO₂、CO₂Hydrocarbons produce hydrogen and value-added chemicals, storing waste/unused electrical energy in the form of conversion to chemicals. SOFC and SOEC are two kinds of mode of operation of same device, can realize fossil energy clean conversion electric energy and renewable energy storage simultaneously. The electrodes (oxygen and fuel electrodes) determine the SOFC and SOEC cell performance and stability. Therefore, the electrochemical catalytic activity and the durability of the electrode are improved, and the method is an important way for promoting the commercial application of the SOFC/SOEC technology. The symmetrical structure single cell can obviously simplify the cell structure and the preparation process, reduce the preparation cost and the energy consumption of the cell, improve the thermal expansion matching among the battery components, and improve the sulfur resistance and the carbon deposition resistance of the cell, thereby improving the operation stability and the reliability of the cell.

ABO₃Although the (SP) type perovskite oxide has the advantages of high electrical conductivity and good oxygen reduction catalytic performance, in the process of long-term high-temperature operation, A site cations such as Sr²⁺、Ba²⁺、Pb²⁺Etc. are susceptible to surface segregation, form non-conductive oxide particles, reduce the electrical conductivity and surface oxygen exchange rate of the electrode, and lead to a deterioration in cell performance and stability over time, such as Sr²⁺SrO nanoparticles are formed by segregation on the surface of the electrode, and SrO is non-conductive and can block the transfer of electrons, so that the reaction rate of the electrode is seriously reduced. At the same time, ABO₃(SP) -type perovskite oxides generally exhibit a high coefficient of thermal expansion in combination with common electrolyte materials such as zirconia-based electrolytes (YSZ, ScSZ, etc.), oxidesThermal expansion of cerium-based electrolytes (GDC, SDC, etc.) is not matched, resulting in delamination cracks between electrodes and electrolytes occurring when a battery is operated at high temperature for a long time, thereby deteriorating stability and durability of the battery.

Disclosure of Invention

The invention aims to provide a heterogeneous interface composite electrode material and a preparation method and application thereof, and solves the problems of insufficient electrochemical performance and stability of the electrode material in SOFC/SOEC. The electrode material can also be used as an oxygen permeable membrane material for membrane electrode separation or a membrane electrode reactor.

The purpose of the invention can be realized by the following technical scheme:

a heterogeneous interface composite electrode material with a chemical formula of La_1-xSr_x+aFe_{1-y- z}N_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。

A preparation method of a heterogeneous interface composite electrode material comprises the following steps: 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.

Further, the Sr-containing compound includes Sr (NO)₃)₂、SrCO₃SrO or SrCl₂One or more of.

Further, the ABO is prepared by adopting a coprecipitation method, a solid phase method or a sol-gel method₃A perovskite-type oxide.

Further, the coprecipitation method is: 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. In the coprecipitation process, the molar ratio of the metal ion mother liquor to the precipitant ammonium bicarbonate is 1: 4.

Further, the solid phase method is: 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 for 6-12h to obtain a composite electrode material precursor, and performing tabletting and high-temperature calcination to obtain the heterogeneous interface composite electrode material.

Further, the sol-gel method is: 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 (EDTA) and Citric Acid (CA) to prepare gel, heating and carbonizing at 250 ℃ to obtain a composite electrode material precursor, and then calcining at high temperature to obtain the heterogeneous interface composite electrode material. The preparation process of the gel comprises the following steps: the reaction was completed by heating at 80 ℃ and then evaporated to give a gel.

Further, the temperature of the high-temperature calcination is 700-1200 ℃, and the time of the high-temperature calcination is 5-20 h. ABO after high temperature calcination₃(SP) -type perovskite and Sr-containing compound to form Ruddlesden-popper (RP) -type lamellar perovskite phase (A)_{n+ 1}B_nO_3n+1And n ═ 1-3), forming an SP-RP composite electrode material.

The composite electrode material is applied to SOFC/SOEC, oxygen permeable membrane, membrane electrode separation and membrane electrode reactors.

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

Studies have shown that Ruddlesden-popper (RP) -type lamellar perovskite phase (A)_n+1B_nO_3n+1N-1-3) type layered perovskites have a high surface exchange rate of oxygen ions and a low coefficient of thermal expansion, and therefore Sr-containing compounds are added to the ABO₃RP type lamellar perovskite oxide is generated on the Surface of (SP) perovskite in situ, and the RP/SP heterogeneous interface is formed between the (SP) perovskite and the (SP) perovskite, so that ABO can be effectively improved₃The surface electron and ion exchange dynamics of the SP electrode improve the thermal expansion matching between the electrode and the electrolyte, and obviously improve the performance and stability of the electrode. However, the RP/SP heterostructure is very sensitive to the spatial dimension and the two-phase distribution, the RP phase oxide has anisotropy, and when the thickness of the RP phase is too large and/or the distribution density is too high, not only the electrode reaction kinetics cannot be improved, but also the electrode performance and stability are damaged. Pulsed Laser Deposition (PLD) can be used to prepare microscopic electrodes with RP/SP heterostructure, but the method is costly, time consuming and difficult to use for the preparation and industrial application of macroscopic porous electrodes. 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 RP/SP composite prepared by the sol-gel co-growth method has particles of RP phase larger than those of SP phase and tends to grow into larger particle sizes with time, resulting in a decrease in conductivity and stability of the electrode.

The ABO is synthesized by the conventional method₃Perovskite oxide La_1-xSr_xFe_1-y-zN_yM_zO_3-δIn the feeding stage, a small amount of Sr-containing compound is additionally added, the Sr-containing compound and the main phase of the perovskite form a small amount of RP-type lamellar perovskite through element migration at high temperature, and the Sr-containing compound and the main phase of the perovskite form a multiphase composite perovskite electrode material containing a heterogeneous interface in an in-situ self-assembly manner. Taking a proper amount of electrode material powder, ball-milling and mixing with pore-forming agents, binders (various organic or inorganic binders) and the like to obtain composite electrode slurry, coating (a spraying method, a spin-coating method, a screen printing method and the like) the composite electrode slurry on the surface of electrolyte, and sintering at high temperature to obtain the SOFC/SOEC composite electrode. The multiphase composite electrode material is in a reducing atmosphereIn the method, metal nanoparticles can be precipitated in situ to form a metal/oxide, layered perovskite RP/perovskite SP oxide multi-heterogeneous interface, so that the conductivity and the electrocatalytic activity of the fuel electrode are obviously improved, and the output power and the stability of a single cell are improved.

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

1) the heterogeneous interface composite electrode material has the characteristic of mixed conductivity of electrons and ions, and can conduct oxygen ions and electrons. The second phase formed in situ and the main phase of perovskite are self-assembled to form a heterogeneous interface, so that the surface oxygen exchange coefficient of the material is improved, and the performance of the oxygen electrode is improved. After metal nano particles are separated out by reduction, the electrocatalytic activity, the conductivity and the stability of the fuel electrode are obviously improved, the polarization impedance is extremely low within 600-1000 ℃, and the output power is high.

2) The heterogeneous interface-containing multiphase composite electrode material is synthesized in situ by one-step self-assembly. The composite electrode material can be used as an oxygen electrode and a fuel electrode at the same time, has double functions of a cathode and an anode, improves the performance of the oxygen electrode, improves the thermal expansion matching of the electrode and an electrolyte, obviously improves the electrocatalytic activity, the conductivity and the stability of the fuel electrode, is prepared in situ by a one-step method, obviously simplifies the preparation process, and is easy to amplify compared with the corresponding single-phase perovskite symmetric electrode material.

Drawings

FIG. 1 shows electrode material La prepared by one-step self-assembly in the example_0.6Sr_0.4+aNi_0.15Fe_0.75Nb_0.1O_3-δ(x ═ 0, 0.1, 0.2) XRD pattern after calcination in air for 10 h.

FIG. 2 shows electrode material La prepared by one-step self-assembly in the example_0.6Sr_0.4+0.1Cu_0.1Fe_0.8Ti_0.1O_3-δXRD patterns after oxidation by 10h in air and reduction by 10h in hydrogen argon atmosphere after n (0, 1, 2, 3) calcines.

FIG. 3 shows electrode material La prepared by one-step self-assembly in the example_0.5Sr_0.5+0.1Cu_0.15Fe_0.8Mo_0.05O_3-δTEM image after calcination in air for 10 h.

FIG. 4 shows electrode material La prepared by one-step self-assembly in the example_0.6Sr_0.4+0.1Fe_0.8Cu_0.15Ti_0.05O_3-δAnd SP type perovskite electrode material La_0.6Sr_0.4Fe_0.8Cu_0.15Ti_0.05O_3-δComparative graph of symmetrical single cell power density of 100h in hydrogen argon atmosphere at 800 ℃.

FIG. 5 shows an example of La of the RP/SP composite electrode material prepared by one-step self-assembly_0.6Sr_{0.4+ 0.1}Fe_0.8Cu_0.15Ti_0.05O_3-δGraph of cell performance in a hydrogen argon atmosphere in the range of 700-.

FIG. 6 shows an example of a one-step self-assembled RP/SP composite electrode material La_0.6Sr_{0.4+ 0.1}Fe_0.8Co_0.1Nb_0.1O_3-δAnd SP type perovskite electrode material La_0.6Sr_0.4Fe_0.8Co_0.1Nb_0.1O_3-δGraph of the change in the coefficient of thermal expansion of (a).

Detailed Description

The invention is described in detail below with reference to the figures and specific embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.

The invention provides a heterogeneous interface composite electrode material, which has a chemical formula of 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。

The invention also provides a preparation method of the heterogeneous interface composite electrode material, which comprises the following steps: 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.

Wherein the Sr-containing compound comprises Sr (NO)₃)₂、SrCO₃SrO or SrCl₂One or more of. Preparing ABO by coprecipitation method, solid phase method or sol-gel method₃A perovskite-type oxide.

The coprecipitation method specifically 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.

The solid phase method comprises the following specific 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.

The sol-gel method comprises the following specific 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 heterointerface composite electrode material.

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

The invention also provides application of the heterogeneous interface composite electrode material, and the composite electrode material is applied to SOFC/SOEC and can be used for SOFC/SOEC symmetrical electrodes, oxygen electrodes or fuel electrodes.

The composite electrode material provided by the invention is prepared by one-step in-situ self-assembly through adjusting the Sr proportion in the initial charge ratio, and the segregation of Sr is effectively inhibited due to the formation of the RP phase with a stable structure, and meanwhile, the electrocatalytic activity and stability of the electrode are improved. Such as one-step self-assembly of RP/SP composite electrode material La_0.6Sr_{0.4+ 0.1}Fe_0.8Cu_0.15Ti_0.05O_3-δ(LSr0.5FCT) prepared symmetrical single cells (LSr0.5FCT/SDC/ScSZ/SDC/LSr0.5FCT) and perovskite SP type electrode material La_0.6Sr_0.4Fe_0.8Cu_0.15Ti_0.05O_3-δCompared with a symmetrical single cell prepared by (LSr0.4FCT), the power density of the LSr0.5FCT at 800 ℃ can reach 450mW cm^-2And after running for 100 hours, the temperature is raised to 460mW cm^-2. While the power density of the LSr0.4FCT symmetrical single cell at 800 ℃ is only 430mW cm^-2And decays to 370mW cm after running for 100h^-2。

Example 1:

La_0.6Sr_0.4+0.2Ni_0.15Fe_0.75Nb_0.1O_3-δpreparation of composite electrode material

6.98g of La was weighed₂O₃、6.21g SrO、1.11g NiO、0.66g Nb₂O₅、5.99g Fe₂O₃Calcining at 400-1000 ℃ for 10h for pretreatment, adding a small amount of absolute ethyl alcohol, and ball-milling at the rotating speed of 350r/min for 24 h; then drying the mixture for 24 hours at 120 ℃ to obtain La_0.6Sr_0.4+0.2Ni_0.15Fe_0.75Nb_0.1O_3-δPressing the electrode material precursor powder under the pressure of 4Mpa for 10min to form a sheet, and calcining in a muffle furnace at 1100 ℃ for 10h to finally obtain the La_0.6Sr_{0.4+ 0.2}Ni_0.15Fe_0.75Nb_0.1O_3-δThe XRD results of the composite electrode material and the powder are shown in FIG. 1, and it can be seen that when x is>At 0, the structure can form a small amount of RP phase in the main phase of the perovskite, namely the existence of SP and RP two phases in the electrode material prepared by one-step self-assembly.

Example 2:

La_0.6Sr_0.4+0.1Cu_0.1Fe_0.8Ti_0.1O_3-δpreparation of composite electrode material

Weighing a certain amount of EDTA and CA, dissolving with a small amount of water, adjusting pH to 8 with ammonia water, weighing 21.65g La (NO)₃)₃·6H₂O、12.71g Sr(NO₃)₂、2.45g Cu(NO₃)₂·6H₂O、32.32gFe(NO₃)₃·9H₂O、2.99g Ti(NO₃)₄Dissolving in water, slowly adding into EDTA-CA mixed solution, adjusting pH to 8, heating in water bath to volatilize water until gel is formed. Heating the gel at 250 ℃ for 5h, carbonizing to obtain an electrode material precursor, and calcining at 900 ℃ for 10h to finally obtain La_0.6Sr_0.4+0.1Cu_0.1Fe_0.8Ti_0.1O_3-δComposite electrode material nano powder. XRD results of the redox cycles of subjecting the powder to n (n ═ 0, 1, 2, 3) calcination in air for 10h of oxidation and calcination in a hydrogen argon atmosphere for 10h of reduction are shown in fig. 2. XRD spectrums of three redox cycles of LSCFT prove that the material can still recover an initial perovskite structure through repeated reduction-oxidation cycles, no impurities are generated, and good redox reversibility of the material is proved.

Example 3:

La_0.5Sr_0.5+0.1Cu_0.15Fe_0.8Mo_0.05O_3-δpreparation of composite electrode material

21.65g La (NO) was weighed out₃)₃·6H₂O、12.71g Sr(NO₃)₂、2.47g Cu(NO₃)₂、2.13gMo(NO₃)₃·5H₂O、28.28g Fe(NO₃)₃·9H₂O, dissolved in water to obtain a nitrate solution, and adding carbonic acidAmmonium hydrogen is used as a precipitator, an electrode material precursor is obtained by mixing through a wet chemical coprecipitation back-drop method, and the electrode material precursor is calcined for 10 hours at 1000 ℃ to obtain La_0.5Sr_{0.5+ 0.1}Cu_0.15Fe_0.8Mo_0.05O_3-δThe TEM results of the composite electrode nanopowder and the powder are shown in FIG. 3, which proves that La is contained in the material_0.5Sr_0.5Cu_0.15Fe_0.8Mo_0.05O_3-δ(SP)、LaSrCu_0.15Fe_0.8Mo_0.05O_4-δ(RP) coexistence of two phases.

Example 4:

la was prepared according to the above method_0.6Sr_0.4+0.1Fe_0.8Cu_0.15Ti_0.05O_3-δMixing the composite electrode material nano powder with terpineol and polymethyl methacrylate according to the mass ratio of 2:1.4:0.3, performing ball milling to obtain electrode slurry, and uniformly coating the electrode slurry on an SSZ electrolyte sheet (SDC/SSZ/SDC) coated with a SDC buffer layer on two sides to obtain the corresponding symmetrical single cell. Measurement of La_0.6Sr_0.4+0.1Fe_0.8Cu_0.15Ti_0.05O_3-δThe performance curve of the single cell of the symmetrical full cell in the hydrogen-argon atmosphere within the range of 700-900 ℃ is shown in the attached figure 5, and the result is used as comparison to obtain the single-phase perovskite La_0.6Sr_0.4Fe_0.8Cu_0.15Ti_0.05O_3-δAnd the power density of a symmetrical single cell taking a conventional electrode LSCM as an electrode at 800 ℃ is much lower than that of the composite electrode.

Will be based on La_0.6Sr_0.4+0.1Fe_0.8Cu_0.15Ti_0.05O_3-δThe symmetrical single cell works for 100 hours at 800 ℃ and 0.7V voltage, and the power density of the electrode material La of SP type perovskite_0.6Sr_0.4Fe_0.8Cu_0.15Ti_0.05O_3-δThe power density comparison result is shown in fig. 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 was prepared according to the above method_0.6Sr_0.4+0.1Fe_0.8Co_0.1Nb_0.1O_3-δThe composite electrode material nano powder is subjected to hydraulic pressure for 10 minutes under 5Mpa to prepare a sample strip. The thermal expansion coefficient of the sample strip was measured using a thermal expansion meter, and compared with that of SP-type perovskite La_0.6Sr_0.4Fe_0.8Co_0.1Nb_0.1O_3-δIn comparison, the thermal expansion coefficient map (TEC) is shown in fig. 6, demonstrating that the composite sample prepared by one-step self-assembly can significantly reduce the thermal expansion coefficient.

The embodiments described above are described to facilitate an understanding and use of the invention by those skilled in the art. It will be readily apparent to those skilled in the art that various modifications to these embodiments may be made, and the generic principles described herein may be applied to other embodiments without the use of the inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications within the scope of the present invention based on the disclosure 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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