CN114016063B - A kind of solid oxide electrolytic cell and preparation method thereof - Google Patents

Abstract

The invention discloses a low-temperature solid oxide electrolytic cell and a preparation method thereof, wherein the electrolytic cell comprises a hydrogen electrode layer, an electrolyte layer, an electron barrier layer, an interlayer and an oxygen electrode layer, wherein the hydrogen electrode layer is NiO and doped cerium oxide Ln _x Ce _1‑x O ₂ The electrolyte layer is doped cerium oxide-based material Ln _x Ce _1‑x O ₂ Ln is one or more of La, gd, sm, pr and Er, x is more than or equal to 0.1 and less than or equal to 0.5, and the electron blocking layer is a doped zirconia-based material M _y Zr _{1‑ y} O ₂ M is one or more of Y, sc, ce, yb, la, gd and Sm, Y is more than or equal to 0 and less than or equal to 0.5, and the interlayer is doped cerium oxide Ln _x Ce _1‑x O ₂ ，Ln _x Ce _1‑x O ₂ Ln is one or more of La, gd, sm, Y, pr and Er, x is more than or equal to 0.1 and less than or equal to 0.5, and the oxygen electrode is a perovskite oxide, a perovskite-like oxide or a composite material formed by the perovskite oxide and doped cerium oxide or the perovskite-like oxide and the doped cerium oxide. The electrolytic cell has excellent performance of low-temperature water electrolysis hydrogen production and power water electrolysis and carbon dioxide electrolysis.

Description

A kind of solid oxide electrolytic cell and preparation method thereof

technical field

The invention relates to the field of fuel cells and electrolytic cells, in particular to a solid oxide electrolytic cell and a preparation method thereof.

Background technique

Solid Oxide Electrolysis Cell (SOEC) can be regarded as the reverse process of solid oxide fuel cell, which can electrolyze water vapor into hydrogen and oxygen at high temperature, or electrolyze water vapor and carbon dioxide into synthesis gas. Its apparent electrical efficiency can reach 100%, and it is currently considered to be the most efficient electrolytic hydrogen production technology.

High cost is an important reason hindering the commercial application of solid oxide fuel cells or electrolytic cells. In order to reduce the cost, the low temperature of solid oxide fuel cells or electrolytic cells has become a research hotspot in this field. Membrane electrode is the core component of SOEC, which has a "sandwich" structure with a dense electrolyte layer in the middle and porous hydrogen and oxygen electrodes on both sides. The ohmic resistance of the electrolyte layer usually occupies the main part of the entire membrane electrode resistance. At present, doped zirconia materials are commonly used as SOEC electrolyte materials, but their low oxygen ion conductivity at low temperatures leads to a significant decrease in battery performance. The doped cerium oxide material has higher oxygen ion conductivity at low temperature, but it has a certain electronic conductivity, which causes the open circuit potential (OCV) of the battery to be lower than the theoretical value and reduces the battery efficiency.

Contents of the invention

Based on the above background technology, the present invention proposes a low-temperature solid oxide electrolytic cell and its preparation method. The electrolytic cell is based on a doped cerium oxide-based electrolyte, which has a lower ohmic resistance and a higher OCV at low temperatures, and realizes excellent performance output. details as follows:

A low-temperature solid oxide electrolytic cell, the electrolytic cell includes a hydrogen electrode layer, an electrolyte layer, an electron blocking layer, an interlayer, and an oxygen electrode layer, wherein the hydrogen electrode layer is NiO and doped cerium oxide Ln _x Ce _1- The composite material composed of _x O ₂ , the mass ratio of NiO to Ln _x Ce _1-x O ₂ is 40:60-70:30, the thickness of the hydrogen electrode layer is 500-2000 nanometers, the porosity is 30-60%, the hydrogen electrode In the layer, Ln is one or more of La, Gd, Sm, Pr, Er, 0.1≤x≤0.5; the electrolyte layer is doped cerium oxide (Ln _x Ce _1-x O ₂ ), Ln is La , Gd, Sm, Pr, Er, one or more, 0.1≤x≤0.5, the thickness of the electrolyte layer is 2-20 microns, and the electron blocking layer is a doped zirconia-based material (M _y Zr _1-y O ₂ ), M is one or more of Y, Sc, Ce, Yb, La, Gd, Sm, 0≤y≤0.5, the electron blocking layer is 2-500 nanometers, and the interlayer is doped cerium oxide ( Ln _x Ce _1-x O ₂ ), Ln is one or more of La, Gd, Sm, Y, Pr, Er, 0.1≤x≤0.5, the thickness of the interlayer is 0.2-5 microns, and the oxygen electrode is calcium Composite materials composed of titanium oxide, perovskite-like oxide or perovskite oxide and doped cerium oxide or perovskite-like oxide and doped cerium oxide, perovskite oxide and doped The mass ratio of cerium oxide is 50:50 to 80:20, the mass ratio of perovskite-like oxide to doped cerium oxide is 50:50 to 80:20, and the thickness of the oxygen electrode layer is 10 to 100 microns. The layer porosity is 30-60%.

Further, in the above technical solution, the thickness of the hydrogen electrode is preferably 800-1500 nanometers, and the porosity is preferably 40-55%.

Further, in the above technical solution, the electrolyte layer is doped cerium oxide (Ln _x Ce _1-x O ₂ ), Ln is preferably one or more of Gd, Sm, Pr, Er, and the thickness of the electrolyte layer is Preferably it is 5-10 microns.

Further, in the above technical solution, the electron blocking layer is a doped zirconia-based material (M _y Zr _{1- y} O ₂ ), M is preferably one or more of Y, La, Gd, Sm , the electron blocking layer is preferably 5-50 nanometers.

Further, in the above technical solution, the interlayer is doped cerium oxide (Ln _x Ce _1-x O ₂ ), Ln is preferably one or more of La, Gd, Sm, Pr, Er, The thickness of the interlayer is preferably 0.2-2 microns.

Further, in the above technical solution, the oxygen electrode is preferably a composite material composed of perovskite oxide and doped cerium oxide or a perovskite-like oxide and doped cerium oxide, and the thickness of the oxygen electrode layer is preferably 20 The porosity of the oxygen electrode layer is preferably 40-55%.

The invention provides the preparation method of the above-mentioned electrolytic cell, the process is as follows: (1) NiO and doped cerium oxide (Ln _x Ce _{1- x} O ₂ ) are mixed and ground according to a certain mass ratio for 5-50 hours to form a hydrogen electrode powder, and Hydrogen electrode powder, toluene, ethanol, fish oil, polyethylene glycol, dioctyl phthalate and polyvinyl butyral are mixed and ball milled for 10-100 hours to form a hydrogen electrode slurry. The ratio of the above raw materials is: 100:60～ 100: 20-50: 1-5: 3-6: 3-6: 6-10, the hydrogen electrode slurry is tape-cast to form a hydrogen electrode green body, and the green body is dried in a high-temperature furnace at 800-1200°C Pre-fire for 2-20 hours to form a hydrogen electrode support; (2) Mix and grind the electrolyte powder with n-butanol, o-benzene, polyvinyl butyral, and fish oil for 10-100 hours to form an electrolyte slurry. The ratio of the above raw materials is: 100: 200-300: 10-40: 10-40: 1-5, the electrolyte slurry is prepared on the hydrogen electrode support by screen printing or direct coating method, and sintered at a high temperature of 1300-1500 °C for 2-20 hours; ( 3) Prepare the electron blocking layer by magnetron sputtering, and anneal at 200-600°C; (4) Prepare an interlayer on the electron-blocking layer by magnetron sputtering, and anneal at 800-1100°C; (5) Mix and grind the oxygen electrode powder with terpineol and ethyl cellulose for 2 to 50 hours to form an oxygen electrode slurry, and prepare the oxygen electrode slurry on the interlayer by screen printing or direct coating method, at a high temperature of 800 to 1200 ℃ sintering for 2 to 10 hours to obtain a full battery.

Further, in the above technical solution, the magnetron sputtering method is used to prepare the electron blocking layer, the sputtering atmosphere is a mixed gas of oxygen and argon, the flow ratio of the two is 1/1 to 1/40, and the sputtering substrate temperature is 100 to 1/40. 400°C, sputtering pressure is 0.1Pa-3.5Pa, sputtering power density P=3-35Wcm ^-2 .

Further, in the above technical solution, the magnetron sputtering method is used to prepare the interlayer, the sputtering atmosphere is a mixture of oxygen and argon, the flow ratio of the two is 1/1 to 1/20, and the sputtering substrate temperature is 100 to 600 °C, the sputtering pressure is 0.1Pa-2Pa, and the sputtering power density is p=3-20Wcm ^-2 .

Beneficial effect of the invention

(1) The present invention is based on a ceria-based electrolyte, and an electron blocking layer My _{Zr 1-y} O ₂ and a spacer layer Ln _x Ce _1-x O ₂ are prepared on the surface of a doped ceria-based electrolyte. The electron blocking layer _My Zr _{The 1-y O2} effectively suppresses the internal leakage problem of doped ceria, and the interlayer avoids the harmful reaction between the electron blocking layer and the highly active Co/Fe-based perovskite-based oxygen electrode at high temperature. Applied to solid oxide electrolytic cells, it can be used to electrolyze water to produce hydrogen, and the operation of electrolytic cells is reliable.

(2) The present invention adopts magnetron sputtering method to prepare electron blocking layer and interlayer, and the homogeneity of electron blocking layer and interlayer is better, and has avoided the process of high-temperature sintering, has avoided electron blocking layer and electrolyte layer, electron blocking A high-resistance Ce-Zr solid solution is formed during high-temperature sintering between layers and interlayers.

specific embodiment

Comparative example 1

A solid oxide electrolytic cell sequentially comprises a hydrogen electrode layer, an electrolyte layer and an oxygen electrode layer. The hydrogen electrode is 1g, of which NiO and Gd _0.2 Ce _0.8 O ₂ are 0.5g respectively, the thickness of the hydrogen electrode layer is 1000 nm, the porosity is 45%, the electrolyte is Gd _0.2 Ce _0.8 O ₂ , and the thickness of the electrolyte layer is 10 microns, The oxygen electrode is La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ -Gd _0.2 Ce _0.8 O ₂ , the mass is 0.01g, of which La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ is 0.006g, Gd _0.2 Ce _0.8 O ₂ is 0.004g , the thickness of the oxygen electrode layer is 50 microns, and the porosity of the oxygen electrode layer is 50%. At 550°C, the OCV of the electrolytic cell is 0.97 when the absolute humidity of the hydrogen electrode side is 3%, the OCV of the electrolytic cell is 0.8V when the absolute humidity is 50%, and the current density is -0.12Acm ^-2 at 1.3V. At 450°C, the OCV of the electrolytic cell is 1.03V when the absolute humidity on the side of the hydrogen electrode is 3%, the OCV of the electrolytic cell is 0.86V when the absolute humidity is 50%, and the current density is -0.03Acm ^{-2 at} 1.3V. The electrolytic cell in Comparative Example 1 includes a hydrogen electrode layer, an electrolyte layer, and an oxygen electrode layer. Due to leakage in the electrolyte layer, the OCV and performance of the electrolytic cell are low.

Example 1

A solid oxide electrolytic cell comprises successively a hydrogen electrode layer, an electrolyte layer, an electron barrier layer, an interlayer, and an oxygen electrode layer, and the hydrogen electrode is 1 g, wherein NiO and Gd _0.2 Ce _0.8 O ₂ are 0.5 g respectively, and the hydrogen electrode The thickness of the layer is 1000 nm, the porosity is 45%, the electrolyte is Gd _0.2 Ce _0.8 O ₂ , the thickness of the electrolyte layer is 10 microns, the material of the electron blocking layer is Y _0.15 Zr _0.85 O ₂ , the thickness of the electron blocking layer is 100 nm, and the interlayer The material is Gd _0.2 Ce _0.8 O ₂ , the thickness of the interlayer is 1 micron, the oxygen electrode is La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ -Gd _0.2 Ce _0.8 O ₂ , the mass is 0.01g, and La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ is 0.006g, Gd _0.2 Ce _0.8 O ₂ is 0.004g, the thickness of the oxygen electrode layer is 50 microns, and the porosity of the oxygen electrode layer is 50%. At 550°C, when the absolute humidity on the side of the hydrogen electrode is 3%, the OCV of the electrolytic cell is 1.02, when the absolute humidity is 50%, the OCV of the electrolytic cell is 0.86V, and the current density at 1.3V is -0.35Acm ^-2 . At 450°C, when the absolute humidity on the side of the hydrogen electrode is 3%, the OCV of the electrolytic cell is 1.10, when the absolute humidity is 50%, the OCV of the electrolytic cell is 0.94V, and the current density at 1.3V is -0.15Acm ^-2 .

The above-mentioned electrolytic cell preparation process is as follows,

(1) NiO (50g) and Gd _0.2 Ce _0.8 O ₂ (50g) were mixed and ground for 24 hours to form a hydrogen electrode powder, and the hydrogen electrode powder, toluene, ethanol, fish oil, polyethylene glycol, phthalic acid di Octyl ester and polyvinyl butyral were mixed and ball-milled for 50 hours to form a hydrogen electrode slurry. The amounts of the above raw materials were: 100g, 80g, 25g, 1g, 3g, 3g, and 8g. The hydrogen electrode slurry was tape-cast to form a hydrogen electrode Embryo, dry the green embryo and pre-fire it in a high-temperature furnace at 1000°C for 5 hours to form a hydrogen electrode support;

(2) Mix and grind the electrolyte Gd _0.2 Ce _0.8 O ₂ powder with n-butanol, o-benzene, polyvinyl butyral, and fish oil for 10 to 100 hours to form an electrolyte slurry. g, 2g, 0.2g, the electrolyte slurry was prepared on the hydrogen electrode support by the screen printing method, and sintered at a high temperature of 1400°C for 10h;

(3) The electron barrier layer was prepared by magnetron sputtering, the sputtering atmosphere was a mixture of oxygen and argon, the flow ratio of the two was 1/15, the sputtering substrate temperature was 400°C, and the sputtering pressure was 0.15Pa. Radiation power density P=10Wcm ^-2 , the sputtered electron blocking layer is annealed at 300°C;

(4) Prepare an interlayer on the electron blocking layer by magnetron sputtering, the sputtering atmosphere is a mixture of oxygen and argon, the flow ratio of the two is 1/10, the sputtering substrate temperature is 400 °C, and the sputtering pressure is 0.5Pa, sputtering power density P = 15Wcm ^-2 , the interlayer after sputtering is annealed at 1000°C for 5h;

(5) La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ (6g), Gd _0.2 Ce _0.8 O ₂ (4g) were mixed and ground for 10h, then mixed with terpineol (4.7g), ethyl cellulose (0.3g) and then Grind for 24 hours to form an oxygen electrode slurry, prepare the oxygen electrode slurry on the separator by screen printing, and sinter at a high temperature of 1000°C for 3 hours to obtain a full battery.

Example 2

A solid oxide electrolytic cell comprises successively a hydrogen electrode layer, an electrolyte layer, an electron barrier layer, an interlayer, and an oxygen electrode layer, and the hydrogen electrode is 1 g, wherein NiO and Gd _0.2 Ce _0.8 O ₂ are 0.5 g respectively, and the hydrogen electrode The thickness of the layer is 1000 nm, the porosity is 45%, the electrolyte is Gd _0.2 Ce _0.8 O ₂ , the thickness of the electrolyte layer is 10 microns, the material of the electron blocking layer is Y _0.15 Zr _0.85 O ₂ , the thickness of the electron blocking layer is 100 nm, and the interlayer The material is Gd _0.2 Ce _0.8 O ₂ , the thickness of the interlayer is 1 micron, the oxygen electrode is La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ -Gd _0.2 Ce _0.8 O ₂ , the mass is 0.01g, and La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ is 0.006g, Gd _0.2 Ce _0.8 O ₂ is 0.004g, the thickness of the oxygen electrode layer is 50 microns, and the porosity of the oxygen electrode layer is 50%.

The above-mentioned electrolytic cell preparation process is as follows,

(1) NiO (50g) and Gd _0.2 Ce _0.8 O ₂ (50g) were mixed and ground for 24 hours to form a hydrogen electrode powder, and the hydrogen electrode powder, toluene, ethanol, fish oil, polyethylene glycol, phthalic acid di Octyl ester and polyvinyl butyral were mixed and ball-milled for 50 hours to form a hydrogen electrode slurry. The amounts of the above raw materials were: 100g, 80g, 25g, 1g, 3g, 3g, and 8g. The hydrogen electrode slurry was tape-cast to form a hydrogen electrode Embryo, dry the green embryo and pre-fire it in a high-temperature furnace at 1000°C for 5 hours to form a hydrogen electrode support;

(2) Mix and grind the electrolyte Gd _0.2 Ce _0.8 O ₂ powder with n-butanol, o-benzene, polyvinyl butyral, and fish oil for 10 to 100 hours to form an electrolyte slurry. g, 2g: 0.2g, prepare the electrolyte slurry to the hydrogen electrode support by the screen printing method, and sinter at a high temperature of 1400°C for 10h;

(3) The electron blocking layer was prepared by screen printing. Y _0.15 Zr _0.85 O ₂ (10g) was mixed with terpineol (10g) and ethyl cellulose (0.5g) and ground for 24 hours to obtain the electron blocking layer slurry. After the electrolyte layer is prepared, it is sintered at a high temperature of 1200 ° C for 10 hours;

(4) The interlayer was prepared by screen printing. Gd _0.2 Ce _0.8 O ₂ (8g) was mixed with terpineol (10g) and ethyl cellulose (0.5g) and ground for 24 hours to obtain interlayer slurry, which was printed on After electron blocking, sintering at a high temperature of 1280°C for 10h;

(5) La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ (6g)-Gd _0.2 Ce _0.8 O ₂ (4g) was mixed and ground for 10h, then mixed with terpineol (4.7g) and ethyl cellulose (0.3g) Grind for 24 hours to form an oxygen electrode slurry, prepare the oxygen electrode slurry on the separator by screen printing, and sinter at a high temperature of 1000°C for 3 hours to obtain a full battery.

The OCV of the above electrolytic cell is 0.99V when the absolute humidity on the side of the hydrogen electrode is 3% at 550°C, the OCV of the electrolytic cell is 0.82V when the absolute humidity is 50%, and the current density at 1.3V is -0.15Acm ^-2 . At 450°C, when the absolute humidity on the side of the hydrogen electrode is 3%, the OCV of the electrolytic cell is 1.06, when the absolute humidity is 50%, the OCV of the electrolytic cell is 0.89V, and the current density at 1.3V is -0.05Acm ^-2 .

By comparing the above examples, it can be seen that the electrolytic cell of the present application effectively improves the performance of the electrolytic cell by adding the electron blocking layer and the interlayer, wherein the electrolytic cell performance of the electron blocking layer and the interlayer is prepared by magnetron sputtering more excellent.

Claims (10)

1. a low-temperature solid oxide electrolytic cell is characterized in that: said electrolytic cell comprises hydrogen electrode layer, electrolyte layer, electron barrier layer, interlayer, oxygen electrode layer successively; Hydrogen electrode layer is NiO and Ln _x Ce _1- Composite materials composed of _x O ₂ ; The electrolyte layer is Ln _x Ce _1-x O ₂ ; the electron blocking layer is M _y Zr _1-y O ₂ , M is one or more of Y, Sc, Ce, Yb, La, Gd, Sm, 0≤ y≤0.5, the electron blocking layer is 2~500 nanometers; the interlayer is Ln _x Ce _1-x O ₂ , and the thickness of the interlayer is 0.2~5 microns; wherein, the hydrogen electrode layer, the electrolyte layer and the Ln in the interlayer _x Ce _1-x O ₂ , Ln are independently selected from one or more of La, Gd, Sm, Y, Pr, Er, 0.1≤x≤0.5. 2. A kind of low-temperature solid oxide electrolytic cell according to claim 1, characterized in that: the mass ratio of hydrogen electrode layer NiO to Ln _x Ce _1-x O ₂ is 40:60 ~ 70:30, and the thickness of hydrogen electrode layer 500-2000 nanometers, porosity 30-60%; The thickness of the electrolyte layer is 2~20 microns; The oxygen electrode layer is perovskite oxide, perovskite-like oxide, or a composite material composed of perovskite oxide and doped cerium oxide, or a composite material composed of perovskite-like oxide and doped cerium oxide Materials, the thickness of the oxygen electrode layer is 10-100 microns, and the porosity of the oxygen electrode layer is 30-60%. 3. A kind of low-temperature solid oxide electrolytic cell according to claim 1, characterized in that: the thickness of the hydrogen electrode is 800~1500 nanometers, and the porosity is 40~55%; the electrolyte layer is Ln _x Ce _{1- x} O ₂ , Ln is one or more of Gd, Sm, Pr, Er, and the thickness of the electrolyte layer is 5-10 microns. 4. A low-temperature solid oxide electrolytic cell according to claim 1, characterized in that: the electron blocking layer is My _{Zr 1-y} O ₂ , and M is one of Y, La, Gd, Sm or Several kinds, the electron blocking layer is 5~50 nanometers. 5. A low-temperature solid oxide electrolytic cell according to claim 1, characterized in that: the interlayer is Ln _x Ce _{1- x} O ₂ , and Ln is one of La, Gd, Sm, Pr, Er or more, the thickness of the interlayer is 0.2-2 microns. 6. A low-temperature solid oxide electrolytic cell according to claim 1, characterized in that: the oxygen electrode layer is perovskite oxide and doped cerium oxide, or perovskite-like oxide and doped cerium oxide The composite material composed of cerium oxide, the mass ratio of perovskite oxide to doped cerium oxide is 50:50~80:20, and the mass ratio of perovskite-like oxide to doped ceria is 50:50~ 80:20, the thickness of the oxygen electrode layer is 20-50 microns, and the porosity of the oxygen electrode layer is 40-55%; the perovskite is (La, Sr)(Co, Fe)O ₃ , (Ba, Sr)( One of Co,Fe)O ₃ , (La,Sr)CoO ₃ , (Sm,Sr)CoO ₃ , (Pr,Sr)CoO ₃ , the perovskite is (La,Sr) ₂ CoO ₄ , (Pr ,Sr) ₂ CoO ₄ , one of (La,Sr) ₂ NiO ₄ . 7. The preparation method of the low-temperature solid oxide electrolytic cell described in any one of claims 1 to 6, characterized in that, comprising the steps of: (1) Mix and grind NiO and Ln _x Ce _1-x O ₂ according to the mass ratio for 5-50 hours to form hydrogen electrode powder, mix hydrogen electrode powder, toluene, ethanol, fish oil, polyethylene glycol, phthalic acid Dioctyl ester and polyvinyl butyral are mixed and ball milled for 10-100 hours to form a hydrogen electrode slurry, and the hydrogen electrode slurry is tape-cast to form a hydrogen electrode green body, which is dried and pre-fired to form a hydrogen electrode support body; (2) Mix and grind the electrolyte powder with n-butanol, phthalate, polyvinyl butyral, and fish oil for 10-100 hours to form an electrolyte slurry, and prepare the electrolyte slurry to the hydrogen electrode by screen printing or direct coating on a support, sintered; (3) Prepare an electron blocking layer My _{Zr 1-y} O ₂ on the electrolyte layer of the hydrogen electrode support obtained in step (2) by magnetron sputtering, and anneal at 200~600°C; (4) The interlayer Ln _x Ce _1-x O ₂ is prepared on the electron blocking layer by magnetron sputtering, and annealed at 800~1100°C; (5) The oxygen electrode slurry is prepared on the separator by screen printing or direct coating method, and sintered to obtain a full battery. 8. The preparation method of the low-temperature solid oxide electrolytic cell according to claim 7, characterized in that: in step (1), the hydrogen electrode powder, toluene, ethanol, fish oil, polyethylene glycol, phthalic acid The raw material ratio of dioctyl ester and polyvinyl butyral is: 100:60~100:20~50:1~5:3~6:3~6:6~10. Pre-burn at 1200℃ for 2~20h; In step (2), the ratio of electrolyte powder to n-butanol, phthalate, polyvinyl butyral, and fish oil is: 100:200~300:10~40:10~40:1~5, hydrogen electrode support The body is sintered at a high temperature of 1300~1500°C for 2~20h; In step (5), mix and grind the oxygen electrode powder with terpineol and ethyl cellulose for 2-50 hours to form an oxygen electrode slurry, and prepare the oxygen electrode slurry on the separator by screen printing or direct coating , and sintered at a high temperature of 800~1200°C for 2~10h to obtain a full battery. 9. The method for preparing a low-temperature solid oxide electrolytic cell according to claim 7, characterized in that: in step (3), the electron barrier layer is prepared by magnetron sputtering, and the sputtering atmosphere is a mixed gas of oxygen and argon, The flow ratio of the two is 1/1~1/40, the sputtering substrate temperature is 100~400°C, the sputtering pressure is 0.1Pa~3.5Pa, and the sputtering power density P=3~35Wcm ^-2 . 10. The method for preparing a low-temperature solid oxide electrolytic cell according to claim 7, characterized in that: in step (4), the interlayer is prepared by magnetron sputtering, and the sputtering atmosphere is a mixed gas of oxygen and argon. The flow rate ratio is 1/1~1/20, the sputtering substrate temperature is 100~600°C, the sputtering pressure is 0.1Pa~2Pa, and the sputtering power density P=3~20Wcm ^-2 .