Cathode material for solid oxide electrolysis cells, and method for preparing same and use thereof

Abstract

The present invention relates to a cathode material for a solid oxide electrolysis cell, as well as its preparation and use. The molecular formula of the cathode material for a solid oxide electrolysis cell is La x Sr 1-x Fe 0.8 Cu y Ni 0.2-y O 3-δ (wherein 0.1≦x≦0.9, 0.01≦y<0.2, and 0≦δ≦0.5). An electrolysis cell prepared by using the cathode material can efficiently convert CO2 and HO into synthesis gas through electrochemical catalysis. Furthermore, the electrolysis cell can perform high-temperature electrolysis of water vapor and / or carbon dioxide at a temperature of 800°C and an electrolysis current density of 0.5 A / cm. 2 As a result, continuous and stable production can be achieved, and industrial applications are expected.

Description

Detailed Description of the Invention

[0001] [Technical field] The present disclosure relates to the technical field of solid oxide electrolytic cells (SOECs), and in particular to cathode materials for solid oxide electrolytic cells and methods for preparing and using the same.

[0002] [Background technology] In recent years, greenhouse gas emission reduction and environmental protection have received increasing attention. Therefore, technologies for efficiently converting and utilizing CO2 have attracted great attention from scientists around the world. As a new type of electrochemical energy storage device, high-temperature solid oxide electrolysis cells can electrolyze CO2 and water vapor to convert them into hydrocarbon fuels such as syngas. High-temperature solid oxide electrolysis cells can efficiently convert electrical energy into chemical energy and are expected to have a wide range of applications.

[0003] Currently, high-temperature electrolysis technology for electrolyzing water vapor has achieved good results at both lab and pilot scales and has been applied in industrial practice. However, the industrial application of high-temperature electrolysis technology for CO2 electrolysis remains largely blank. To realize the large-scale industrial application of high-temperature electrolysis technology for CO2 electrolysis, it is necessary to simultaneously satisfy the requirements of high yield and operational stability. That is, high-temperature electrolysis for CO2 electrolysis requires a large current density (e.g., >0.5 A / cm). 2 ) must be operated continuously and stably. High performance requirements can be placed on the cathode (also known as the hydrogen electrode) of an electrolysis cell. On the one hand, CO2 has a much more stable molecular structure than H2O molecules, so the decomposition of CO2 is more difficult than that of H2O both thermodynamically and kinetically, potentially requiring a higher catalytic activity from the cathode. On the other hand, CO2 electrolysis can be accompanied by side reactions such as carbon deposition, which can place high demands on the operational stability of the cathode material.

[0004] Although the activity and stability of currently developed SOEC cathode materials may have improved to a certain extent in high-temperature electrolysis, they still do not meet the requirements for continuous and stable electrolysis of CO2 at high temperatures and large currents.

[0005] CN104388972A discloses a cathode material for a solid oxide electrolysis cell and its use. The related hydrogen electrode material is SrFe 1-x M x MoO 6-δ where 0≦x≦1.0; M is at least one metal ion selected from the group consisting of Mg, Zn, Ni, Co, Cu, and Mn. The hydrogen electrode material has remarkably high electrochemical performance and high efficiency during electrochemical high-temperature H2O decomposition and hydrogen production. However, the electrode material has not been reported to be used in high-temperature CO2 electrolysis.

[0006] CN113782798A discloses a hydrogen electrode material for a solid oxide electrolysis cell and a method for using the same. The hydrogen electrode material for a solid oxide electrolysis cell is made of La 1-x Sr x Fe 1-y Nb y O 3-δ where 0.1≦x≦0.6, 0.1≦y≦0.2, and 0≦δ≦0.5. This hydrogen electrode material can maintain chemical stability in high temperature and high humidity environments and reducing atmospheres, and can have relatively high catalytic activity for the electrochemical reduction of HO and CO, with a maximum current of 0.71 A / cm in a mixed atmosphere of water vapor and carbon dioxide. 2 The electrolytic current density can be stably increased.

[0007] CN106498435A discloses a cathode material for a solid oxide electrolysis cell and its preparation method. The hydrogen electrode material for a solid oxide electrolysis cell is La x Sr 0.9-x Ti 0.6 Ni 0.4 O 3-δThe hydrogen electrode material has a molecular formula of 0.2≦x≦0.8, where 0.2≦x≦0.8. It is said that the hydrogen electrode material has Ni metal nanoparticles eluted in situ on its surface, which improves catalytic activity and reduces polarization resistance. Furthermore, it can maintain structural stability even at high electrolysis voltages and exhibit good electrocatalytic performance. However, the electrode material has not been reported to be used in CO2 electrolysis at high temperatures.

[0008] Although prior art cathode materials may perform well in the high-temperature electrolysis of HO or HO / CO mixtures, their use in the high-temperature electrolysis of CO has rarely been reported. In particular, there are few reports of using these electrode materials in the high-temperature electrolysis of CO at high current densities (i.e., >0.5 A / cm). 2 There have been no reports of continuous and stable high-temperature electrolysis of CO2 using these cathode materials in SOECs. The reason for this may be that current SOEC cathode materials may have insufficient catalytic activity and stability for the electrochemical conversion of water vapor and carbon dioxide.

[0009] To address the above issues, the following difficulties may be encountered: CO2 has a much more stable molecular structure than H2O molecules, making CO2 electrolysis more difficult to achieve than H2O electrolysis in terms of both thermodynamics and kinetics, and may require higher catalytic activity from the cathode. In addition, CO2 electrolysis may involve side reactions such as carbon deposition on the cathode, which may impose higher requirements on the operational stability of the cathode during electrolysis.

[0010] [Summary of the Invention] The present disclosure addresses the problems of insufficient activity for CO2 electrolysis and difficulty in electrolysis at high current densities associated with prior art cathode materials. In this regard, the present disclosure provides a perovskite oxide-type cathode material with high activity and high stability, and an electrolysis cell using the cathode material. The cathode material and electrolysis cell according to the present disclosure can efficiently convert CO2 and HO into synthesis gas through electrochemical catalysis, thereby realizing efficient conversion and utilization of carbon-based energy. Furthermore, the cathode material and electrolysis cell according to the present disclosure can achieve a current density of 0.5 A / cm2 or higher. 2 At current densities above this, stable operation of the electrolysis of CO or H O, respectively, can be achieved. The present disclosure also relates to methods for preparing the cathode material and electrolysis cell, and uses of the cathode material and electrolysis cell.

[0011] In a first aspect, the present disclosure provides La x Sr 1-x Fe 0.8 Cu y Ni 0.2-y O 3-δ A cathode material for a solid oxide electrolysis cell is provided having a molecular formula:

[0012] In a second aspect, the present disclosure provides a method for preparing the above-described cathode material for a solid oxide electrolysis cell, comprising the steps of: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt, and optionally a complexing agent, followed by drying and calcination to obtain a cathode material; wherein the lanthanum, strontium, iron, copper, and nickel salts of the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of x:(1-x):0.8:y:(0.2-y), where 0.1≦x≦0.9 and 0.01≦y<0.2.

[0013] In a third aspect, the present disclosure provides the use of a solid oxide electrolysis cell cathode material as described above or prepared by the method as described above in the preparation of a solid oxide electrolysis cell.

[0014] In a fourth aspect, the present disclosure provides a method for preparing a solid oxide electrolysis cell, the method comprising the steps of: applying an anode material and a cathode material, respectively, to each of the two faces of the solid electrolyte; and reducing the cathode material; Here, the cathode material is the cathode material described above or the cathode material prepared by the method described above.

[0015] In a fifth aspect, the present disclosure provides a solid oxide electrolysis cell prepared by the method described above.

[0016] In a sixth aspect, the present disclosure provides the use of the solid oxide electrolysis cell described above in the electrolysis of water vapor and / or carbon dioxide.

[0017] The present disclosure may include the following items.

[0018] 1.La 0.6 Sr 0.4 Fe 0.8 Cu x Ni y O 3-δ wherein 0.01≦x≦0.2, 0.01≦y≦0.2, and x+y=0.2; Preferably, the cathode material for a solid oxide electrolysis cell is characterized in that 0.05≦x≦0.15 and 0.05≦y≦0.15.

[0019] 2. A method for preparing the cathode material for a solid oxide electrolysis cell according to item 1, comprising the following steps: A1: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt and water to obtain a mixed solution; A2: mixing the mixed solution with ethylenediaminetetraacetic acid, adjusting the pH to 7-10, and then drying and baking; Here, in step A1, the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of 0.6:0.4:0.8:x:y.

[0020] 3. The method according to item 2, wherein in step A2, the ethylenediaminetetraacetic acid and the metal ions in the mixed solution are in a molar ratio of 1 to 1.5:1.

[0021] 4. The method according to item 2 or 3, wherein the metal ions are present in the mixed solution at a total content of 1 to 2 mol / L.

[0022] 5. The method according to any one of items 2 to 4, wherein in step A2, the firing is carried out under conditions of a firing temperature of 600 to 800°C and a firing time of 1 to 2 hours.

[0023] 6. Use of the cathode material for a solid oxide electrolysis cell according to item 1 or the cathode material for a solid oxide electrolysis cell prepared by the method according to any one of items 2 to 5 in preparing a solid oxide electrolysis cell.

[0024] 7. A method for preparing a solid oxide electrolysis cell, comprising the steps of: B1: tableting the electrolyte powder and calcining it to obtain an electrolyte support; B2: preparing a cathode slurry from a cathode material and a binder, and preparing an anode slurry from an anode material and a binder; B3: applying the cathode slurry and the anode slurry to each of the two surfaces of the electrolyte support by screen printing, respectively, and firing, and then placing the surface containing the cathode material in a reducing atmosphere for reduction; Here, the cathode material is the cathode material described in item 1 or a cathode material prepared by the method of any one of items 2 to 5.

[0025] 8. The method according to item 7, wherein in step B1, the electrolyte is selected from yttria-doped zirconia.

[0026] 9. The method according to item 7 or 8, wherein in step B1, the firing is carried out under conditions of a firing temperature of 1300 to 1500°C and a firing time of 2 to 4 hours.

[0027] 10. In step B2, the anode material is selected from perovskite oxide materials; Preferably, the anode material is La 0.6 Sr 0.4 CoO 3-δ , La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ and La 0.6 Sr 0.4 MnO 3-δ 10. The method according to any one of items 7 to 9, wherein the method is one or more selected from the group consisting of:

[0028] 11. The method according to item 7, wherein in step B3, the firing is carried out under conditions of a firing temperature of 600 to 800°C and a firing time of 1 to 2 hours.

[0029] 12. In step B3, the reducing atmosphere is a mixture of hydrogen and nitrogen: 8. The method according to item 7, wherein the mixture of hydrogen and nitrogen preferably contains hydrogen at a volume fraction of 10 to 20%.

[0030] 13. The method according to item 7, wherein in step B3, the reduction is carried out under conditions of a reduction temperature of 800°C and a reduction time of 1 to 3 hours.

[0031] 14. A solid oxide electrolysis cell prepared by the method according to any one of items 7 to 13.

[0032] 15. Use of the solid oxide electrolysis cell according to item 14 in the electrolysis of water vapor and / or carbon dioxide.

[0033] Compared with the prior art, the present invention may have the following advantages:

[0034] 1. The cathode material of the solid oxide electrolysis cell according to the present disclosure is a perovskite-type oxide that exhibits excellent oxygen ion conductivity at high temperatures. The cathode material according to the present disclosure contains copper and nickel, and the cathode material exhibits improved catalytic activity for the electrolysis of carbon dioxide and high-temperature steam. In addition, the introduction of copper and nickel into the perovskite oxide produces a synergistic effect that is advantageous for the efficient electrolysis of steam and / or carbon dioxide.

[0035] 2. In the case of a solid oxide electrolysis cell based on the cathode material for solid oxide electrolysis cells according to the present disclosure, the cathode material is reduced in a reducing atmosphere, resulting in the in-situ elution of Cu-Ni alloy on its surface. The eluted Cu-Ni alloy grows on the surface of the perovskite oxide body in the form of nanoparticles. The Cu-Ni alloy nanoparticles present on the surface are sufficient to significantly improve catalytic activity and carbon deposition resistance. The obtained solid oxide electrolysis cell was tested at a temperature of 800°C and an electrolysis current density of 0.5 A / cm. 2 As a result, continuous and stable high-temperature electrolysis of water vapor and / or carbon dioxide can be achieved, which is expected to be useful for industrial applications. [Drawing Description]

[0036] FIG. 1 is a schematic diagram of a solid oxide electrolysis cell according to the present disclosure. Figure 2 shows the SEM and DES results obtained in Test 1. FIG. 3 shows the XRD results obtained in Test 1. FIG. 4 shows the results of the high-temperature electrolysis of water vapor in Test 3. FIG. 5 shows the results of the high-temperature electrolysis of carbon dioxide in Test 3. FIG. 6 shows SEM images of the solid oxide electrolysis cell of Example 1 before and after operation for high temperature electrolysis of carbon dioxide in Test 3.

[0037] Reference number 1 anode 2 solid electrolyte 3 cathodes 4Cu-Ni alloy nanoparticles

[0038] [Detailed explanation] The present invention will now be described in more detail with reference to its embodiments. It should be noted that the described embodiments are provided for illustrative purposes only and are not intended to be limiting in any way.

[0039] It should be understood that the values ​​disclosed herein (including the range endpoints) are not limited to the exact values, but encompass values ​​close to those values. Furthermore, ranges of values ​​can be defined between the endpoints of the ranges, between the endpoints of the ranges and individual points, and between the individual points, to provide one or more new ranges of values, just as if those ranges of values ​​were specifically disclosed herein.

[0040] Except for the Examples, all values ​​of parameters herein are understood to be modified in all instances by the term "about," regardless of whether "about" actually appears before the value.

[0041] In one embodiment, the present disclosure provides a compound having the molecular formula La x Sr 1-x Fe 0.8 Cu y Ni 0.2-y O 3-δ wherein 0.1≦x≦0.9, 0.01≦y<0.2, and 0≦δ≦0.5.

[0042] Preferably, 0.2≦x≦0.8, and more preferably, 0.4≦x≦0.6. For example, x may be 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, or 0.9. In one variation, x is 0.6.

[0043] Preferably, 0.05≦y≦0.15, and more preferably, 0.08≦y≦0.12. For example, y can be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, or 0.19. In one variation, y is 0.1.

[0044] In one variation, the cathode material for the solid oxide electrolysis cell is La 0.6 Sr 0.4 Fe 0.8 Cu y Ni 0.2-y O 3-δ where 0.01≦y<0.2 and 0≦δ≦0.5.

[0045] δ represents the number of oxygen vacancies.

[0046] In some variations, the cathode material according to the present disclosure may further include Cu—Ni alloy nanoparticles on its surface.

[0047] The cathode material according to the present disclosure is a perovskite oxide. Cathode materials in the form of perovskite oxides can have excellent oxygen ion conductivity at high temperatures. When used in a solid oxide electrolysis cell, the cathode material undergoes reduction, resulting in the in-situ elution of Cu-Ni alloys. The eluted Cu-Ni alloys grow on the surface of the perovskite oxide body in the form of nanoparticles. The perovskite oxide body and the Cu-Ni alloy can provide a synergistic effect, achieving efficient electrolysis of water vapor and / or carbon dioxide. The presence of the in-situ eluted Cu-Ni alloy nanoparticles on the surface of the perovskite oxide body facilitates coordination between Ni and Cu, thereby significantly improving the catalytic activity of the cathode for carbon dioxide / high-temperature water vapor electrolysis. At the same time, the in-situ eluted Cu-Ni alloy nanoparticles cover at least a portion of the surface of the perovskite phase, resulting in advantageous carbon deposition resistance. This solves the problem of electrode carbon deposition that tends to occur during high-temperature electrolysis of carbon dioxide using conventional solid oxide electrolysis cells, thereby significantly improving the operational stability of the resulting electrolysis cell.

[0048] In a second aspect, the present disclosure provides a method for preparing the above-described cathode material for a solid oxide electrolysis cell, comprising the steps of: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt, and optionally a complexing agent, followed by drying and calcination to obtain a cathode material; wherein the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of x:(1-x):0.8:y:(0.2-y), where 0.1≦x≦0.9 and 0.01≦y<0.2.

[0049] In this specification, the expression "optionally, a complexing agent" means that a complexing agent may or may not be added when mixing the lanthanum salt, the strontium salt, the iron salt, the copper salt, and the nickel salt. Preferably, a complexing agent is added.

[0050] In one embodiment, the method may include the following steps: A1: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt and water to obtain a mixed solution; A2: mixing the mixed solution with a complexing agent, adjusting the pH of the resulting mixture to 7-10, and then drying and calcining the mixture to obtain a cathode material; wherein in step A1, the lanthanum, strontium, iron, copper, and nickel salts of the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of x:(1-x):0.8:y:(0.2-y), where 0.1≦x≦0.9 and 0.01≦y<0.2.

[0051] In one embodiment, the lanthanum salt, strontium salt, iron salt, copper salt, and nickel salt are each independently a water-soluble salt, preferably each independently one or more salts selected from the group consisting of chlorides, sulfates, and nitrates, more preferably all nitrates.

[0052] In one embodiment, the complexing agent is one or more selected from the group consisting of ethanolamine complexing agents, aminocarboxylic acid complexing agents, hydroxyaminocarboxylic acid complexing agents, and carboxylic acid complexing agents, and is preferably at least one selected from the group consisting of diethanolamine, ethylenediaminetetraacetic acid (EDTA) and salts thereof (potassium salt, sodium salt, etc.), diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetetraacetic acid (HEDTA), dihydroxyglycine and salts thereof, and hydroxyethylaminoacetic acid (DHEG) and salts thereof, and more preferably ethylenediaminetetraacetic acid.

[0053] The mixing method in step A1 is not particularly limited, and various mixing methods commonly used in the technical field, such as stirring and ultrasonic mixing, can be used.

[0054] Preferably, in step A2, the molar ratio of ethylenediaminetetraacetic acid to total metal ions in the mixed solution is 1 to 1.5: 1. For example, the molar ratio of ethylenediaminetetraacetic acid to total metal ions in the mixed solution may be 1:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1, or 1.5:1.

[0055] Preferably, the metal ions are present in the mixed solution at a total content of 1 to 2 mol / L, for example, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, or 2 mol / L.

[0056] In step A2, the mixture is transformed into a gel by adjusting the pH to between 7 and 10, preferably between 8 and 9. In one variant, the pH may be adjusted by using aqueous ammonia.

[0057] In step A2, the drying may be carried out at a temperature of 100 to 150°C.

[0058] In step A2, the firing may be carried out at a firing temperature of 600 to 800° C. for a firing time of 1 to 2 hours. For example, the firing temperature may be 600° C., 620° C., 640° C., 650° C., 660° C., 680° C., 700° C., 720° C., 740° C., 750° C., 760° C., 780° C., or 800° C., and the firing time may be 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, or 2 hours.

[0059] In step A2, the firing may include a step of heating to a firing temperature at a rate of 5 to 10° C. / min and firing at the firing temperature.

[0060] In step A2, the firing is carried out in an oxygen-containing atmosphere, which may be, for example, oxygen, air, or ozone.

[0061] In a third aspect, the present disclosure provides the use of the solid oxide electrolysis cell cathode material described above or prepared by the method described above in the preparation of a solid oxide electrolysis cell.

[0062] Preferably, the solid oxide electrolysis cell is used to electrolyze water vapor or carbon dioxide.

[0063] In a fourth aspect, the present disclosure provides a method for preparing a solid oxide electrolysis cell, the method comprising the steps of: applying an anode material and a cathode material, respectively, to each of the two faces of the solid electrolyte; and reducing the cathode material; Here, the cathode material is the cathode material described above or the cathode material prepared by the method described above.

[0064] In the method according to the present disclosure, the electrolyte may be selected from various electrolyte materials commonly used in the art. Preferably, the electrolyte is selected from the group consisting of yttria-doped zirconia (or yttria-stabilized zirconia, YSZ), gadolinia-doped ceria (GDC), lanthanum strontium gallium magnesium oxide (LSGM), etc., and is preferably YSZ.

[0065] In one embodiment, the solid electrolyte can be obtained by the following steps: B1: The electrolyte powder is compressed into tablets and calcined to obtain a solid electrolyte.

[0066] Sintering the electrolyte powder can impart higher strength. In step B1, the sintering can be performed under conditions of a sintering temperature of 1300 to 1500°C and a sintering time of 2 to 4 hours. For example, the sintering temperature may be 1300°C, 1350°C, 1400°C, or 1500°C, and the sintering time may be 2 hours, 3 hours, or 4 hours.

[0067] In one embodiment, applying the anode material and the cathode material, respectively, to each of the two faces of the solid electrolyte may include the following steps: B2: preparing a cathode slurry from a cathode material and a binder, and preparing an anode slurry from an anode material and a binder; and B3: Applying the cathode slurry and the anode slurry to each of two sides of the solid electrolyte, respectively, and then firing to form a cathode and an anode on each side of the solid electrolyte, respectively.

[0068] In step B2, preparing a cathode slurry from a cathode material and a binder includes: The method may include mixing the cathode material and the liquid binder and subjecting them to grinding to obtain a cathode slurry.

[0069] Preferably, the cathode material and the liquid binder are used in a weight ratio of 0.5 to 1.5:1, for example, the ratio may be 3:2, 4:3, 1:1, 3:4 or 2:3.

[0070] In step B2, preparing an anode slurry from an anode material and a binder includes: The method may include mixing the anode material and the liquid binder and subjecting them to grinding to obtain an anode slurry.

[0071] Preferably, the anode material and the liquid binder are used in a weight ratio of 0.5 to 1.5:1, for example, the ratio may be 3:2, 4:3, 1:1, 3:4 or 2:3.

[0072] In the present disclosure, the binder is not particularly limited. Various binders conventionally used in the art can be used. For example, the binder may be a cellulose such as methyl cellulose, ethyl cellulose, carboxymethyl cellulose, or carboxyethyl cellulose. Other binders, such as polyvinyl butyral (PVB) or sodium polyacrylate (NaPAA), can also be used. For ease of operation, the binder is used in the form of a liquid binder. Liquid binders are typically formed by mixing a low-molecular-weight compound with the binder. In one embodiment, the liquid binder is a mixture of terpineol and ethyl cellulose, preferably a mixture of terpineol and ethyl cellulose in a weight ratio of 15 to 25:1. In one variation, the liquid binder is a mixture of ethanol and polyvinyl butyral.

[0073] In step B2, the anode material is selected from perovskite oxide materials. Preferably, the anode material is La 0.6 Sr 0.4 CoO 3-δ (LSC), La 0.6 Sr 0.4 Co 0.8 Fe 0.2 O 3-δ and La 0.6 Sr 0.4 MnO 3-δ where 0≦δ≦0.5.

[0074] The method for applying the cathode slurry and the anode slurry in the present disclosure is not particularly limited. Methods commonly used in the technical field, such as spin coating, blade coating, spray coating, and screen printing, can be used. In the examples, the case of using screen printing is illustrated.

[0075] In step B3, the firing can be performed at a firing temperature of 600 to 800°C for a firing time of 1 to 2 hours. For example, the firing temperature may be 600°C, 620°C, 640°C, 650°C, 660°C, 680°C, 700°C, 720°C, 740°C, 750°C, 760°C, 780°C, or 800°C, and the firing time may be 1 hour, 1.1 hours, 1.2 hours, 1.3 hours, 1.4 hours, 1.5 hours, 1.6 hours, 1.7 hours, 1.8 hours, 1.9 hours, or 2 hours.

[0076] In step B3, the firing may include a step of heating to a firing temperature at a rate of 5 to 10° C. / min and firing at the firing temperature.

[0077] In step B3, the firing is carried out in an oxygen-containing atmosphere, which may be, for example, oxygen, air, or ozone.

[0078] In one embodiment, reducing the cathodic material may include placing a surface of a solid electrode containing the cathodic material in a reducing atmosphere to reduce the cathodic material.

[0079] Preferably, the reducing atmosphere is a mixture of hydrogen and nitrogen. More preferably, the mixture of hydrogen and nitrogen contains hydrogen at a volume fraction of 10 to 20%. For example, the hydrogen may be present at a volume fraction of 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20%.

[0080] The reduction may be carried out at a reduction temperature of 750 to 850°C for a reduction time of 1 to 3 hours. For example, the reduction temperature may be 750°C, 760°C, 770°C, 780°C, 790°C, 800°C, 810°C, 820°C, 830°C, 840°C, or 850°C, and the reduction time may be 1 hour, 1.5 hours, 2 hours, 2.5 hours, or 3 hours.

[0081] The reduction may cause Cu-Ni alloy nanoparticles to form in situ on the surface of the cathode.

[0082] In a fifth aspect, the present disclosure provides a solid oxide electrolysis cell prepared by the above-described method. The solid oxide electrolysis cell may have a structure commonly used in the art. Generally, an oxide electrolysis cell may include an anode, a cathode, and a solid electrolyte between the cathode and the anode, which are arranged in sequence. Figure 1 is a cross-sectional schematic diagram of a solid oxide electrolysis cell according to the present disclosure. As shown in Figure 1, the solid oxide electrolysis cell includes an anode 1, a solid electrolyte 2, and a cathode 3, which are arranged in sequence, and Cu-Ni alloy nanoparticles 4 are present on the surface of the cathode 3.

[0083] By using the solid oxide electrolysis cell prepared by the method according to the present disclosure, not only can high-temperature water vapor electrolysis be achieved, but also the efficient and stable operation of CO electrolysis can be ensured, thereby giving the present invention good prospects for efficiently converting CO and HO into synthesis gas.

[0084] In a sixth aspect, the present disclosure provides the use of the solid oxide electrolysis cell described above in the electrolysis of water vapor or carbon dioxide.

[0085] [Example] The present invention will be described in detail through the following examples, all of which are intended to illustrate the present invention but not to limit the present invention in any way.

[0086] All materials used in the examples were commercially available.

[0087] Example 1 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.005 mol of copper nitrate, and 0.005 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.1 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolysis cell with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0088] Preparation of solid oxide electrolysis cell: The electrolyte (yttria-doped zirconia, YSZ) powder was tableted and fired in a muffle furnace at 1400 °C for 2 hours to obtain a solid electrolyte. The obtained cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then subjected to pulverization to prepare a cathode slurry, and the anode material (La 0.6 Sr 0.4 CoO 3-δ , LSC) was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry, where the liquid binder was a mixture of terpineol and ethyl cellulose in a 20:1 weight ratio. The cathode slurry and anode slurry were applied to each of the two sides of a solid electrolyte by screen printing, heated in a muffle furnace at a rate of 5°C / min to a temperature of 800°C, and calcined at this temperature for 2 hours. The side of the solid electrolyte containing the cathode material was then placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800°C for 2 hours to obtain a solid oxide electrolyte cell S1.

[0089] Example 2 Preparation of cathode material for solid oxide electrolyte cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.0025 mol of copper nitrate, and 0.0075 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.1 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 9 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte cathode material with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.05 Ni 0.15 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0090] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1400 °C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare a cathode slurry; the LSC powder was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry. The liquid binder was a 20:1 weight ratio mixture of terpineol and ethyl cellulose. The cathode and anode slurries were applied to each of the two sides of the solid electrolyte by screen printing, heated to 800 °C at a rate of 5 °C / min in a muffle furnace, and calcined at this temperature for 2 hours. The side of the solid electrolyte containing the cathode material was then placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800 °C for 2 hours to obtain solid oxide electrolyte cell S2.

[0091] Example 3 Preparation of cathode material for solid oxide electrolyte cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.006 mol of copper nitrate, and 0.004 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 1.05 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.12 Ni 0.08 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0092] Fabrication of a solid oxide electrolysis cell: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1400 °C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry. The liquid binder was a 20:1 weight ratio mixture of terpineol and ethyl cellulose. The cathode and anode slurries were applied to each of the two sides of a solid electrolyte by screen printing, heated to 800 °C at a rate of 5 °C / min in a muffle furnace, and calcined at this temperature for 2 hours. The side of the solid electrolyte containing the cathode material was then placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800 °C for 2 hours to obtain solid oxide electrolyte cell S3.

[0093] Example 4 Preparation of cathode material for solid oxide electrolyte cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.004 mol of copper nitrate, and 0.006 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.11 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.08 Ni 0.12 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolyte cell having the above formula was obtained.

[0094] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1400 °C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry. The liquid binder was a 20:1 weight ratio mixture of terpineol and ethyl cellulose. The cathode and anode slurries were applied to each of the two sides of the solid electrolyte by screen printing, heated to 800 °C at a rate of 5 °C / min in a muffle furnace, and calcined at this temperature for 2 hours. The side of the solid electrolyte containing the cathode material was then placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800 °C for 2 hours to obtain solid oxide electrolyte cell S4.

[0095] Example 5 Preparation of cathode material for solid oxide electrolyte cells: 0.06 mol of lanthanum nitrate, 0.04 mol of strontium nitrate, 0.08 mol of iron nitrate, 0.01 mol of copper nitrate, and 0.01 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.22 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 120 °C and then heated to 750 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolyte cell having the above formula was obtained.

[0096] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1450°C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a weight ratio of 2:3 and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a weight ratio of 2:3 and then ground to prepare an anode slurry. Here, the liquid binder was a mixture of terpineol and ethyl cellulose in a weight ratio of 21:1. The cathode and anode slurries were applied by screen printing to each of the two sides of the solid electrolyte obtained in step B1, heated to a temperature of 800°C in a muffle furnace at a rate of 5°C / min, and calcined at this temperature for 2 hours. Thereafter, the solid electrolyte surface containing the cathode material was placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800° C. for 2 hours to obtain a solid oxide electrolyte cell S5.

[0097] Example 6 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.005 mol of copper nitrate, and 0.005 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.14 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 9 with aqueous ammonia while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 700 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0098] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1500°C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a weight ratio of 3:2 and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a weight ratio of 3:2 and then ground to prepare an anode slurry. Here, the liquid binder was a mixture of terpineol and ethyl cellulose in a weight ratio of 19:1. The cathode and anode slurries were applied to each of the two sides of the solid electrolyte by screen printing and heated in a muffle furnace at a rate of 5°C / min to a temperature of 750°C and calcined at this temperature for 2 hours. Thereafter, the solid electrolyte surface containing the cathode material was placed in a reducing atmosphere (a mixture of 10% hydrogen and 90% nitrogen) and reduced at 800° C. for 2 hours to obtain a solid oxide electrolyte cell S6.

[0099] Example 7 Preparation of cathode material for solid oxide electrolyte cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.005 mol of copper nitrate, and 0.005 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.12 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolyte with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolyte cell having the above formula was obtained.

[0100] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1400°C for 2 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry. Here, the liquid binder was a mixture of terpineol and ethyl cellulose in a 20:1 weight ratio. The cathode and anode slurries were applied to each of the two sides of the solid electrolyte by screen printing and heated in a muffle furnace at a rate of 5°C / min to a temperature of 800°C and calcined at this temperature for 2 hours. Thereafter, the solid electrolyte surface containing the cathode material was placed in a reducing atmosphere (a mixture of 5% hydrogen and 95% nitrogen) and reduced at 800° C. for 1.5 hours to obtain a solid oxide electrolyte cell S7.

[0101] Example 8 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.04 mol of iron nitrate, 0.005 mol of copper nitrate, and 0.005 mol of nickel nitrate were added to 100 mL of deionized water and stirred to dissolve the salts, resulting in a mixed solution. 0.13 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a solid oxide electrolysis cell with the molecular formula La. 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0102] Preparation of solid oxide electrolysis cells: The electrolyte YSZ powder was tableted and calcined in a muffle furnace at 1500°C for 1.5 hours to obtain a solid electrolyte. The resulting cathode material for the solid oxide electrolysis cell was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare a cathode slurry. The LSC powder was mixed with a liquid binder in a 1:1 weight ratio and then ground to prepare an anode slurry. Here, the liquid binder was a mixture of terpineol and ethyl cellulose in a 20:1 weight ratio. The cathode and anode slurries were applied to each of the two sides of the solid electrolyte by screen printing and heated in a muffle furnace at a rate of 5°C / min to a temperature of 800°C and calcined at this temperature for 2 hours. The solid electrolyte surface containing the cathode material was then placed in a reducing atmosphere (a mixture of 20% hydrogen and 80% nitrogen) and reduced at 800° C. for 3 hours to obtain a solid oxide electrolyte cell S8.

[0103] Comparative Example 1 The preparation of the solid oxide electrolysis cell of Example 1 was repeated, except that the cathode material for a solid oxide electrolysis cell obtained in Example 1 was replaced with a commercially available cathode material, Ni-YSZ, to obtain a solid oxide electrolysis cell D1.

[0104] Comparative Example 2 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, and 0.05 mol of iron nitrate were added to 100 mL of deionized water to obtain a mixed solution. 0.12 mol of citric acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water under stirring. The resulting mixture was converted into a gel. This gel was dried at 100 °C and then heated to 800 °C in a muffle furnace at a heating rate of 5 °C / min in an air atmosphere and calcined at that temperature for 2 hours to obtain a solid oxide electrolysis cell cathode material with the molecular formula La. 0.6 Sr 0.4 FeO 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0105] The preparation of the solid oxide electrolysis cell of Example 1 was repeated using the obtained cathode material for a solid oxide electrolysis cell to obtain a solid oxide electrolysis cell D2.

[0106] Comparative Example 3 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.045 mol of iron nitrate, and 0.005 mol of nickel nitrate were added to 100 mL of deionized water to obtain a mixed solution. 0.1 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was transformed into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace in an air atmosphere at a heating rate of 5 °C / min and calcined at that temperature for 2 hours to obtain a cathode material with the molecular formula La. 0.6 Sr 0.4 Fe 0.9 Ni 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0107] The preparation of the solid oxide electrolysis cell of Example 1 was repeated using the obtained cathode material for a solid oxide electrolysis cell, to obtain a solid oxide electrolysis cell D3.

[0108] Comparative Example 4 Preparation of cathode material for solid oxide electrolysis cells: 0.03 mol of lanthanum nitrate, 0.02 mol of strontium nitrate, 0.045 mol of iron nitrate, and 0.005 mol of copper nitrate were added to 100 mL of deionized water to obtain a mixed solution. 0.11 mol of ethylenediaminetetraacetic acid was added to this mixed solution, and the pH was adjusted to 8 with ammonia water while stirring. The resulting mixture was converted into a gel. The gel was dried at 100 °C and then heated to 800 °C in a muffle furnace at a heating rate of 5 °C / min in an air atmosphere and calcined at that temperature for 2 hours to obtain a cathode material with the molecular formula La. 0.6 Sr 0.4 Fe 0.9 Cu 0.1 O 3-δ Thus, a powder of a cathode material for a solid oxide electrolysis cell having the above formula was obtained.

[0109] The preparation of the solid oxide electrolysis cell of Example 1 was repeated using the obtained cathode material for a solid oxide electrolysis cell to obtain a solid oxide electrolyte cell D4.

[0110] Test 1 The solid oxide electrolysis cell obtained in Example 1 was examined using a scanning electron microscope (SEM) Gemini SEM 500 (Carl Zeiss, China) under conditions of an accelerating voltage of 10 kV and an electron beam current of 10 nA. The interface between the cathode and the solid electrolyte is shown in Figure 2A; the surface morphology of the cathode is shown in Figure 2B. Furthermore, the element distribution on the surface of the test area was characterized using a scanning electron microscope Gemini SEM 500 (Carl Zeiss, China) equipped with an energy dispersive X-ray spectrometer (EDS). The results are shown in Figure 2C and 2D.

[0111] As shown in Figure 2, in the solid oxide electrolysis cell according to the present disclosure, the solid electrolyte had a dense morphology, and the cathode had a loose and porous morphology. The cathode and the solid electrolyte were firmly bonded. Furthermore, numerous small nanoscale particles, mainly composed of Ni and Cu, were present on the surface of the cathode of the solid oxide electrolysis cell, as detected by EDS.

[0112] The changes in the cathode material of the solid oxide electrolysis cell in Example 1 before and after reduction were detected using a D8 ADVANCE X-ray diffractometer (XRD) (Bruker, Germany). Figure 3 shows the XRD patterns. The bottom XRD pattern is for the cathode material for the solid oxide electrolysis cell before reduction, and the top XRD pattern is for the cathode material after reduction. Comparison of the two patterns reveals new peaks at 2θ = 34.1°, 2θ = 44.6°, and 2θ = 50.4° in the latter. Comparison with the standard PDFs of copper and nickel confirmed that these new peaks corresponded to the characteristic peaks of Ni(110), Ni(111), and Cu(200) of copper and nickel, respectively. Considering the results of Figures 2 and 3 together, it can be concluded that metallic copper and nickel appeared on the surface of the cathode of the solid oxide electrolysis cell during reduction, thereby confirming the formation of Cu-Ni alloy nanoparticles.

[0113] The XRD patterns in FIG. 3 also show that, before and after reduction, the cathode material for a solid oxide electrolysis cell of Example 1 essentially consists of an oxide composite material, containing a small amount of a single metal oxide such as La2O3, and the main component of the cathode material for a solid oxide electrolysis cell of Example 1 is a perovskite-type oxide.

[0114] Test 2 The electrochemical performance of the solid oxide electrolysis cells obtained in Examples 1 to 8 and Comparative Examples 1 to 4 was tested using an electrochemical workstation IM6ex (manufactured by Zanher GmbH, Germany).

[0115] The test sample was connected to the circuit, sealed, and subjected to a polarization impedance test of the electrolytic cell. The test was performed under the following conditions: a temperature of 800°C, air as the cathode atmosphere, a mixture of 40% water vapor, 10% hydrogen, and 50% nitrogen as the anode atmosphere, and a disturbance voltage of 10 mV. The polarization impedance results of the solid oxide electrolytic cell are shown in Table 1.

[0116] [Table 1]

[0117] As can be seen from Table 1, the solid oxide electrolysis cells using the cathode materials according to the present disclosure generally had low polarization impedance, indicating that the cathode materials according to the present disclosure have excellent electrochemical performance.

[0118] Test 3 Solid oxide electrolysis cells S1 and D1 were operated at 800°C and 0.5 A / cm, respectively. 2 The high-temperature electrolysis of water vapor and carbon dioxide was carried out at a constant current density of 1000 kJ / s. The high-temperature electrolysis of water vapor was carried out under conditions of air as the anode atmosphere, a mixture of 50% nitrogen and 50% water vapor as the cathode atmosphere, and atmospheric pressure. The results of the high-temperature electrolysis of water vapor are shown in Figure 4. The high-temperature electrolysis of carbon dioxide was carried out under conditions of air as the anode atmosphere, a mixture of 50% nitrogen and 50% carbon dioxide as the cathode atmosphere, and atmospheric pressure. The results of the high-temperature electrolysis of carbon dioxide are shown in Figure 5.

[0119] 4 and 5, in the solid oxide electrolysis cell of Example 1, the high-temperature electrolysis of water vapor and the high-temperature electrolysis of carbon dioxide at 800°C were operated at a lower electrolysis voltage than in the solid oxide electrolysis cell of Comparative Example 1. Referring to FIG. 5, by using the solid oxide electrolysis cell of Comparative Example 1 (based on the cathode material Ni-YSZ), the electrolysis was performed at a constant current density of 0.5 A / cm 2 During continuous electrolysis of carbon dioxide for 1 hour at 400 K, the electrolysis voltage increased significantly. However, the solid oxide electrolysis cell of Example 1 (cathode material La 0.6 Sr 0.4 Fe 0.8 Cu 0.1 Ni 0.1 O 3-δ By using the cathode material and solid oxide electrolysis cell of Example 1 (based on Example 1), the electrolysis voltage was kept substantially constant during the electrolysis of carbon dioxide under the same conditions. This demonstrates that the cathode material and solid oxide electrolysis cell of Example 1 have higher robustness for the high-temperature electrolysis of carbon dioxide.

[0120] The solid oxide electrolysis cell obtained in Example 1 was examined using a scanning electron microscope (SEM) to examine the morphology of the solid oxide electrolysis cell before and after high-temperature electrolysis of carbon dioxide. The results are shown in Figure 6. In the figure, "a" on the left represents the morphology of the cathode surface before high-temperature electrolysis of carbon dioxide, and "b" on the right represents the morphology of the cathode surface after high-temperature electrolysis of carbon dioxide. As can be seen from comparing the two, the morphology of the cathode surface did not change before and after high-temperature electrolysis of carbon dioxide when using the solid oxide electrolysis cell obtained in Example 1, and elemental carbon was not detected on the surface. Furthermore, it was demonstrated that the cathode material for solid oxide electrolyte cells and the solid oxide electrolyte cell obtained in Example 1 have excellent carbon deposition resistance.

[0121] As can be seen from the above tests, the solid oxide electrolysis cells prepared using the cathode materials according to the present disclosure had excellent catalytic performance and stability, which was of great significance in realizing stable operation of high-temperature electrolysis of water vapor and / or carbon dioxide.

[0122] The embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Various simple modifications can be made to the embodiments of the present invention, including the combination of various technical features in any other suitable manner, within the technical scope of the present invention. These simple modifications and combinations are also the contents disclosed in this specification and should be considered to be within the protection scope of the present disclosure. [Brief explanation of the drawings]

[0123] [Figure 1] FIG. 1 is a schematic diagram of a solid oxide electrolysis cell according to the present disclosure. [Figure 2] Figure 2 shows the SEM and DES results obtained in Test 1. [Figure 3] FIG. 3 shows the XRD results obtained in Test 1. [Figure 4] FIG. 4 shows the results of the high-temperature electrolysis of water vapor in Test 3. [Figure 5]FIG. 5 shows the results of the high-temperature electrolysis of carbon dioxide in Test 3. [Figure 6] FIG. 6 shows SEM images of the solid oxide electrolysis cell of Example 1 before and after operation for high temperature electrolysis of carbon dioxide in Test 3.

Claims

1. La ｘ Sr １－ｘ Fe ０．８ Cu ｙ Ni ０．２－ｙ O ３－δ 1. A cathode material for a solid oxide electrolysis cell having a molecular formula:

2. 10. The cathode material for a solid oxide electrolysis cell according to claim 1, further comprising Cu-Ni alloy nanoparticles on a surface thereof.

3. 10. A method for preparing the cathode material for a solid oxide electrolysis cell of claim 1, comprising the steps of: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt and an optional complexing agent, followed by drying and calcination to obtain a cathode material; wherein the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of x:(1-x):0.8:y:(0.2-y), where 0.1≦x≦0.9 and 0.01≦y<0.

2.

4. 4. The method of claim 3, comprising the steps of: A1: mixing a lanthanum salt, a strontium salt, an iron salt, a copper salt, a nickel salt and water to obtain a mixed solution; A2: mixing the mixed solution with the complexing agent, adjusting the pH of the resulting mixture to pH 7-10, and then drying and calcining; wherein in step A1, the lanthanum, strontium, iron, copper, and nickel salts of the lanthanum, strontium, iron, copper, and nickel salts are in a molar ratio of x:(1−x):0.8:y:(0.2−y), where 0.1≦x≦0.9 and 0.01≦y<0.

2.

5. the complexing agent is at least one selected from the group consisting of diethanolamine, ethylenediaminetetraacetic acid (EDTA) and its salts, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylenediaminetetraacetic acid (HEDTA), dihydroxyglycine and its salts, and hydroxyethylaminoacetic acid (DHEG) and its salts; Preferably, the complexing agent is ethylenediaminetetraacetic acid, wherein the ethylenediaminetetraacetic acid and the metal ions in the mixed solution are in a molar ratio of 1-1.5:1; or The method according to claim 4, wherein the mixed solution preferably contains metal ions with a total content of 1-2 mol / L.

6. The method according to any one of claims 4 to 5, wherein in step A2, the firing is carried out under conditions of a firing temperature of 600 to 800°C and a firing time of 1 to 2 hours.

7. 1. A method for preparing a solid oxide electrolysis cell, comprising the steps of: applying an anode material and a cathode material, respectively, to each of the two faces of the solid electrolyte; and reducing the cathode material; Here, the cathode material is the cathode material described in claim 1.

8. 8. The method of claim 7, wherein the solid electrolyte is obtained by the following steps: B1: Compressing the electrolyte powder into tablets and calcining to obtain a solid electrolyte; Preferably, the electrolyte is yttria-doped zirconia; or Preferably, in step B1, the firing is carried out under conditions of a firing temperature of 1300 to 1500° C. and a firing time of 2 to 4 hours.

9. 8. The method of claim 7, wherein applying the anode material and the cathode material to each of two sides of the solid electrolyte, respectively, comprises the steps of: B2: preparing a cathode slurry from the cathode material and a binder, and preparing an anode slurry from the anode material and a binder; B3: Applying the cathode slurry and the anode slurry to each of two sides of the solid electrolyte, respectively, and firing to form a cathode and an anode, respectively, on each side of the solid electrolyte.

10. preparing the cathode slurry from the cathode material and the binder by: mixing the cathode material and the liquid binder and subjecting them to grinding to obtain the cathode slurry; and preparing the anode slurry from the anode material and the binder, mixing the anode material and the liquid binder and subjecting them to grinding to obtain the anode slurry; Preferably, the cathode material and the liquid binder are used in a weight ratio of 0.5 to 1.5:1; the anode material and the liquid binder are used in a weight ratio of 0.5 to 1.5:1; Preferably, the liquid binder is a mixture of terpineol and ethyl cellulose in a weight ratio of 15 to 25:

1.

10. The method of claim 9.

11. the anode material is selected from perovskite oxide materials; Preferably, the anode material is La ０．６ Sr ０．４ CoO ３－δ , La ０．６ Sr ０．４ Co ０．８ Fe ０．２ O ３－δ and La ０．６ Sr ０．４ MnO ３－δ The method of any one of claims 7 to 10, wherein δ is one or more selected from the group consisting of:

12. The method according to claim 9, wherein in step B3, the firing is carried out under conditions of a firing temperature of 600 to 800°C and a firing time of 1 to 2 hours.

13. The step of reducing the cathode material includes: placing a surface of the solid electrode containing the cathode material in a reducing atmosphere to reduce the cathode material; Preferably, the reducing atmosphere is a mixture of hydrogen and nitrogen, more preferably the reducing atmosphere is a mixture of hydrogen and nitrogen with a volume fraction of hydrogen of 10-20%, or Preferably, the reduction is carried out under conditions of a reduction temperature of 800°C and a reduction time of 1 to 3 hours; or Preferably, the reduction forms Cu—Ni alloy nanoparticles in situ on the cathode surface. The method of claim 7.

14. A solid oxide electrolysis cell prepared by the method of any one of claims 7 to 13.

15. 15. Use of the solid oxide electrolysis cell according to claim 14 in the electrolysis of water vapor and / or carbon dioxide.

Images