A proton-conductor type electrolytic cell, its preparation method and application

Abstract

This invention discloses a proton-conducting electrolytic cell, its preparation method, and its application, belonging to the field of solid oxide electrolytic cells. The electrolytic cell is composed of a hydrogen electrode I, a hydrogen electrode II, a proton-conducting electrolyte layer, and an oxygen electrode layer stacked sequentially. The hydrogen electrode I and hydrogen electrode II are nickel oxide-proton-conducting oxide composite materials, and the proton-conducting electrolyte is BaCe. 1‑x‑y Zr x Y y O 3‑δ The parameters are: 0.1≤x≤0.8, 0≤y≤0.2, 0≤δ≤0.5; the oxygen electrode is a perovskite oxide or a perovskite oxide-proton-conducting oxide composite material. The electrolytic cell prepared by this method exhibits excellent water electrolysis performance and stability.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of solid oxide electrolysis cell, and particularly relates to a proton conductor type electrolysis cell and a preparation method and application thereof. BACKGROUND

[0002] Solid oxide electrolysis cell (SOEC) can utilize renewable energy such as wind energy and solar energy to electrolyze water vapor to prepare "green hydrogen", and the electric efficiency can reach 100%, and the system efficiency can reach 90%. However, the operating temperature of the oxygen ion conductor type SOEC is usually above 750 DEG C, and the high temperature operation leads to serious problems of oxidation of the bipolar plate and element diffusion between components. In recent years, the proton conductive type SOEC has attracted widespread attention. The proton conductive activation energy is 0.3-0.5 eV, which is lower than the oxygen ion conductive activation energy (0.8-0.9 eV), so that the proton conductive type SOEC is expected to maintain high performance at an operating temperature of 400-600 DEG C. However, the actual proton conductive type SOEC does not show the expected performance. Researchers have found that the ohmic resistance of the cell is much higher than the theoretical value, which is due to the fact that the Ba(Ce,Zr)O3-based electrolyte material is sintered at a temperature above 1400 DEG C, and the interface of the electrolyte material is heterogeneous phase precipitation and the volatilization of Ba element, which leads to the reduction of the ionic conductivity of the electrolyte; on the other hand, the high temperature sintering destroys the electrode-electrolyte interface, which ultimately leads to the large ohmic resistance and polarization resistance of the electrolysis cell. Therefore, how to improve the ionic conductivity of the electrolyte film, improve the interface contact between the electrolyte and the electrode, and further improve the performance of the electrolysis cell is a research hotspot in the field. SUMMARY

[0003] In order to solve the problems existing in the prior art, the present application provides a proton conductive type electrolysis cell and a preparation method and application thereof, which can exhibit excellent water electrolysis performance at 350-600 DEG C

[0004] The present application provides a preparation method of a proton conductive type electrolysis cell, which is stacked by a hydrogen electrode I, a hydrogen electrode II, a proton conductive type electrolyte layer and an oxygen electrode layer in sequence; the hydrogen electrode I and the hydrogen electrode II are both nickel oxide-proton conductive oxide composite materials; the proton conductive electrolyte and the proton conductive oxide are both BaCe 1-x-y Zr x Y y O 3-δ , 0.1≤x≤0.8, 0≤y≤0.2, 0≤δ≤0.5; the oxygen electrode is a perovskite oxide or a perovskite oxide-proton conductive oxide composite material;

[0005] The preparation method comprises the following steps,

[0006] (1) Hydrogen electrode I forming: hydrogen electrode I is prepared by a casting or extrusion method, and pre-sintering is performed;

[0007] (2) Hydrogen electrode-electrolyte co-sintering: hydrogen electrode II is prepared on one side surface of the pre-sintered hydrogen electrode I, and drying is performed; a proton-conducting electrolyte layer is prepared on the surface of the hydrogen electrode II, and hydrogen electrode I, hydrogen electrode II and the proton-conducting electrolyte layer are co-sintered;

[0008] (3) Surface treatment of the proton-conducting electrolyte layer with a surfactant;

[0009] (4) Oxygen electrode sintering: an oxygen electrode layer is prepared on the surface of the treated electrolyte layer, and a proton-conducting cell is obtained after sintering.

[0010] Further, the mass ratio of nickel oxide to proton-conducting oxide in the hydrogen electrode I is 50:50 to 80:20, and the mass ratio of nickel oxide to proton-conducting oxide in the hydrogen electrode II is 40:60 to 60:40.

[0011] Further, the thickness of the hydrogen electrode I is 300 to 1500 microns, the thickness of the hydrogen electrode II is 5 to 30 microns, the thickness of the proton-conducting electrolyte layer is 5 to 50 microns, and the thickness of the oxygen electrode layer is 10 to 50 microns.

[0012] Further, the oxygen electrode is a perovskite oxide including an electron-ion mixed conductor perovskite oxide; and the perovskite oxide-proton-conducting oxide composite material includes an electron-ion mixed conductor perovskite oxide and -BaCe 1-x-y Zr x Y y O 3-δ composite material.

[0013] Further, the pre-sintering temperature in step (1) is 800 to 1200°C, and the pre-sintering time is 1 to 10 hours; the co-sintering temperature in step (2) is 1300 to 1500°C, and the co-sintering time is 5 to 20 hours; and the sintering temperature in step (4) is 700 to 1100°C, and the sintering time is 1 to 10 hours.

[0014] Further, the drying temperature in step (2) is 60 to 80°C.

[0015] Further, the surfactant in step (3) includes an inorganic acid or an organic acid; the amount of the surfactant is 1 to 10 mmol / cm 2 , and the treatment time is 1 to 60 minutes.

[0016] Further, the inorganic acid includes one or both of hydrochloric acid and sulfuric acid, and the organic acid includes one or more than two of formic acid, acetic acid and citric acid.

[0017] Further, the surface active agent is preferably an inorganic acid.

[0018] The application also provides a proton-conducting electrolytic cell prepared by the above method.

[0019] The application also provides the use of the above proton-conducting electrolytic cell in the electrolysis of water vapor to produce hydrogen, the electrolysis of carbon dioxide to produce carbon monoxide, or the electrolysis of water vapor and carbon dioxide to produce synthesis gas.

[0020] The electrolytic cell typically operates at a temperature of 350-600°C.

[0021] Advantages of the application

[0022] (1) The electrolytic cell of the application, by treating the surface of the electrolyte with a surface active agent, effectively improves the chemical bonding and mechanical connection between the electrolyte and the oxygen electrode, increases the active sites of the water splitting reaction on the oxygen electrode, significantly reduces the ohmic resistance and polarization resistance of the electrolyte, and eliminates the element segregation on the surface of the electrolyte after high-temperature sintering, establishing a clean electrolyte surface and improving the proton conductivity of the electrolyte. The electrolytic cell of the application exhibits excellent water electrolysis performance at 350-600°C.

[0023] (2) The preparation of the electrolyte of the application involves processes such as casting, extrusion, and sintering, which are simple and easy to scale up. The surface pretreatment process of the electrolyte is low in cost and has universality, which can effectively promote the development of low-temperature electrolytic cells. DETAILED DESCRIPTION

[0024] The following non-limiting examples can enable those skilled in the art to more fully understand the application, but in no way limit the application.

[0025] Comparative Example 1

[0026] A proton-conducting electrolytic cell, which is stacked in sequence by a hydrogen electrode I, a hydrogen electrode II, a proton-conducting electrolyte layer, and an oxygen electrode layer. The hydrogen electrode I of the electrolytic cell is 0.6 g of NiO and 0.4 g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode I is 1000 microns, the hydrogen electrode II is 0.015 g of NiO and 0.015 g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode II is 30 microns, and the proton-conducting electrolyte layer is BaCe 0.7 Zr 0.1 Y0.2 O 2.9 , the thickness of the layer is 10 microns, the composition of the oxygen electrode layer is Sm 0.5 Sr 0.5 CoO3, the thickness of the oxygen electrode layer is 30 microns.

[0027] The electrolytic cell is prepared as follows: first, 0.6 g of NiO and 0.4 g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 are mixed at a mass ratio of 6:4, ground for 24 h, and cast into a 2 cm*2 cm disc, which is pre-fired at 800°C for 2 h to form a hydrogen electrode I. Next, a layer of hydrogen electrode II slurry is screen printed on one side surface of the hydrogen electrode I, dried at 80°C for 5 h, and then a layer of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 electrolyte slurry is screen printed, and sintered at 1400°C for 10 h. Finally, an oxygen electrode layer is coated on the surface of the electrolyte layer, sintered at 1000°C for 2 h, to obtain a complete electrolytic cell.

[0028] The electrolytic cell is operated in a water vapor electrolysis mode, and when the electrolysis voltage is 1.3 V, the operating temperature is 400°C, the electrolysis current density reaches -0.07 A / cm 2 , and when the operating temperature is 600°C, the electrolysis current density reaches -0.3 A / cm 2 .

[0029] Example 1

[0030] A proton-conducting electrolytic cell, which is stacked in sequence by a hydrogen electrode I, a hydrogen electrode II, a proton-conducting electrolyte layer, and an oxygen electrode layer. The hydrogen electrode I of the electrolytic cell is a composite material composed of 0.6 g of NiO and 0.4 g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode I is 1000 microns, the hydrogen electrode II is a composite material composed of 0.015 g of NiO and 0.015 g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode II is 30 microns, the proton-conducting electrolyte layer is BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the layer is 10 microns, and the oxygen electrode layer is Sm 0.5 Sr 0.5 CoO3, the thickness of the oxygen electrode layer is 30 microns.

[0031] The electrolytic cell is prepared as follows: first, NiO and BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 are mixed and ground for 24 hours, and then cast into a 2cm*2cm round sheet, which is pre-fired at 800°C for 2 hours to form a hydrogen electrode I. Second, a layer of hydrogen electrode II is screen-printed on one side surface of the hydrogen electrode I, and dried at 80°C for 5 hours, and then a layer of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 electrolyte layer is screen-printed on the hydrogen electrode II, and sintered at 1400°C for 10 hours. Third, a 0.5mol / L hydrochloric acid aqueous solution surfactant is prepared, and the surfactant is added dropwise to the surface of the electrolyte layer in an amount of 5mmol / cm 2 , and left for 10 minutes, and then the surfactant is removed, and the electrolyte surface is washed with deionized water and dried. Finally, an oxygen electrode layer is coated on the surface of the treated electrolyte layer, and sintered at 1000°C for 2 hours to obtain a complete electrolytic cell.

[0032] The electrolytic cell is operated in a water vapor electrolysis mode, and when the electrolysis voltage is 1.3V, the operating temperature is 400°C, and the electrolysis current density reaches -0.7A / cm 2 , and when the operating temperature is 600°C, the electrolysis current density reaches -2.7A / cm 2 . It can be seen that the electrolyte surface treatment process greatly improves the performance of the electrolytic cell.

[0033] Example 2

[0034] A proton-conducting electrolytic cell is stacked in sequence by a hydrogen electrode I, a hydrogen electrode II, a proton-conducting electrolyte layer, and an oxygen electrode layer. The hydrogen electrode I of the electrolytic cell is a composite material composed of 0.6g of NiO and 0.4g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode I is 1000 microns, the hydrogen electrode II is a composite material composed of 0.015g of NiO and 0.015g of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the hydrogen electrode II is 30 microns, the proton-conducting electrolyte layer is BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 , the thickness of the layer is 10 microns, and the oxygen electrode layer is Sm 0.5 Sr 0.5CoO3, and the thickness of the oxygen electrode layer is 30 microns.

[0035] The electrolytic cell is prepared as follows: first, NiO and BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 are mixed and ground for 24 hours, and then are cast into a 2cm*2cm disc, which is pre-fired at 800℃ for 2 hours to form a hydrogen electrode I. Second, a layer of hydrogen electrode II is coated on one side surface of the hydrogen electrode I, and after drying at 80℃ for 5 hours, a layer of BaCe 0.7 Zr 0.1 Y 0.2 O 2.9 electrolyte paste is sintered at 1400℃ for 10 hours. Third, a 0.5mol / L acetic acid aqueous solution surfactant is prepared, and the surfactant is added dropwise to the surface of the electrolyte according to the amount of 5mmol / cm 2 , and is left for 10 minutes, and then the surfactant is removed, and the electrolyte surface is washed with deionized water and dried. Finally, an oxygen electrode layer is coated on the surface of the treated electrolyte layer, and is sintered at 1000℃ for 2 hours to obtain a complete electrolytic cell.

[0036] The electrolytic cell is operated in a water vapor electrolysis mode, and when the electrolysis voltage is 1.3V, the operating temperature is 400℃, and the electrolysis current density reaches -0.1A / cm 2 , and when the operating temperature is 600℃, the electrolysis current density reaches -1.9A / cm 2 . It can be seen that the effect of treating the electrolyte surface with acetic acid is worse than that of treating the electrolyte surface with hydrochloric acid, but is still significantly improved compared with the comparative example 1.

[0037] Example 3

[0038] A proton-conducting electrolytic cell is stacked by a hydrogen electrode I, a hydrogen electrode II, a proton-conducting electrolyte layer, and an oxygen electrode layer in sequence. The hydrogen electrode I of the electrolytic cell is a composite material composed of 0.7g of NiO and 0.3g of BaZr 0.8 Y 0.2 O 2.9 , the thickness of the hydrogen electrode I is 1000 microns, the hydrogen electrode II is a composite material composed of 0.015g of NiO and 0.015g of BaZr 0.8 Y 0.2 O 2.9 , the thickness of the hydrogen electrode II is 30 microns, the proton-conducting electrolyte layer is BaZr 0.8 Y 0.2 O 2.9 , the thickness of the layer is 8 microns, and the oxygen electrode layer is composed of 0.07g of Sm 0.5 Sr 0.5CoO3 and 0.03 g BaZr 0.8 Y 0.2 O 2.9 The thickness of the oxygen electrode layer is 30 microns.

[0039] The electrolytic cell is prepared as follows: first, NiO and BaZr 0.8 Y 0.2 O 2.9 are mixed and ground in a mass ratio of 7:3 for 24 hours, and then cast into a 2 cm*2 cm disc, which is pre-fired at 1000°C for 2 hours to form a hydrogen electrode I. Second, a layer of hydrogen electrode II is screen-printed on one side surface of the hydrogen electrode I, and dried at 80°C for 5 hours, and then a layer of BaZr 0.8 Y 0.2 O 2.9 electrolyte is screen-printed on the hydrogen electrode II, and sintered at 1500°C for 10 hours. Third, a 0.5 mol / L hydrochloric acid aqueous solution surfactant is prepared, and the surfactant is added dropwise to the surface of the electrolyte in an amount of 8 mmol / cm 2 , and left for 15 minutes, and then the surfactant is removed, and the electrolyte surface is washed with deionized water and dried. Finally, an oxygen electrode layer is coated on the surface of the treated electrolyte layer, and sintered at 1000°C for 2 hours to obtain a complete electrolytic cell.

[0040] The electrolytic cell is operated in a water vapor electrolysis mode, and when the electrolysis voltage is 1.3V, the operating temperature is 400°C, and the electrolysis current density reaches -0.5A / cm 2 , and when the operating temperature is 600°C, the electrolysis current density reaches -2.1A / cm 2 . It can be seen that the method has universality, and excellent technical effects are shown for different electrolyte compositions and different electrode systems.

Claims

1. A method of making a proton-conducting electrolytic cell, characterized by: The electrolytic cell is stacked by hydrogen electrode I, hydrogen electrode II, proton-conducting electrolyte layer and oxygen electrode layer in sequence; the hydrogen electrode I and the hydrogen electrode II are both nickel oxide-proton-conducting oxide composite material; the proton-conducting electrolyte and the proton-conducting oxide are both BaCe 1-x-y Zr x Y y O 3-δ , 0.1≤x≤0.8, 0≤y≤0.2, 0≤δ≤0.5; the oxygen electrode is perovskite oxide or perovskite oxide-proton-conducting oxide composite material; The preparation method comprises the following steps, (1) hydrogen electrode I forming: hydrogen electrode I is prepared by a flow casting or extrusion method, and pre-sintering is performed; (2) hydrogen electrode-electrolyte co-sintering: hydrogen electrode II is prepared on one side surface of the pre-sintered hydrogen electrode I, and drying is performed; a proton-conducting electrolyte layer is prepared on the surface of the hydrogen electrode II, and the hydrogen electrode I, the hydrogen electrode II and the proton-conducting electrolyte layer are co-sintered; (3) treating the surface of the proton-conducting electrolyte layer with a surfactant; (4) oxygen electrode sintering: an oxygen electrode layer is prepared on the surface of the treated electrolyte layer, and a proton-conducting electrolytic cell is obtained after sintering. The surface active agent in step (3) is one or both of hydrochloric acid and sulfuric acid, or one or more of formic acid, acetic acid, and citric acid. The amount of the surface active agent is 1 to 10 mmol / cm 2 .

2. A method of making a proton-conducting electrolytic cell according to claim 1, characterized in that: The mass ratio of nickel oxide to proton-conducting oxide in the hydrogen electrode I is 50:50-80:20, and the mass ratio of nickel oxide to proton-conducting oxide in the hydrogen electrode II is 40:60-60:

40.

3. A method of making a proton-conducting electrolytic cell according to claim 1, wherein: The thickness of the hydrogen electrode I is 300-1500 microns, the thickness of the hydrogen electrode II is 5-30 microns, the thickness of the proton-conducting electrolyte layer is 5-50 microns, and the thickness of the oxygen electrode layer is 10-50 microns.

4. A method of making a proton-conducting electrolytic cell according to claim 1, wherein: The oxygen electrode is a perovskite oxide including an electron-ion mixed conductor perovskite oxide; and the perovskite oxide-proton conductive oxide composite material includes an electron-ion mixed conductor perovskite oxide and -BaCe 1-x-y Zr x Y y O 3-δ composite.

5. A method of making a proton-conducting electrolytic cell according to claim 1, wherein: The pre-sintering temperature in step (1) is 800-1200 DEG C, and the pre-sintering time is 1-10 h; the co-sintering temperature in step (2) is 1300-1500 DEG C, and the co-sintering time is 5-20 h; and the sintering temperature in step (4) is 700-1100 DEG C, and the sintering time is 1-10 h.

6. The method of claim 1, wherein: The drying temperature in step (2) is 60-80 DEG C.

7. A method of making a proton-conducting electrolytic cell according to claim 1, wherein: The treatment time in step (3) is 1-60 min.

8. The proton-conducting electrolytic cell prepared by the preparation method in any one of claims 1-7.

9. Use of a proton-conducting electrolytic cell according to claim 8, characterized in that: It is applied to electrolysis of water vapor to prepare hydrogen, electrolysis of carbon dioxide to prepare carbon monoxide, or electrolysis of water vapor and carbon dioxide to prepare synthetic gas.