A proton-conductor electrolyte cell composite membrane, membrane electrode and preparation method

Abstract

The application discloses a kind of proton conductor electrolytic cell composite membranes, membrane electrode and preparation method, belong to fuel cell and electrolytic cell field.The composite membrane is by the proton conductor base electrolyte layer, zirconium oxide base electrolyte film layer and cerium oxide base electrolyte film layer of close connection in turn composition;Proton conductor base electrolyte layer material is BaZr 1‑ z N z O3, 0.01≤z<1;Zirconium oxide base electrolyte film layer material is M y Zr 1‑y O2, 0.01≤y≤0.5;Cerium oxide base electrolyte film layer material is Ln x Ce 1‑x O2, 0.01≤x≤0.5.The composite membrane base electrolytic cell has very low proton transmission resistance and larger electron block resistance, and shows excellent electrolytic performance at 400-600 DEG C.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of fuel cells and electrolytic cells, and particularly relates to a proton conductor electrolytic cell composite membrane, a membrane electrode and a preparation method. BACKGROUND

[0002] A 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 electrical efficiency can reach 100%, and the system efficiency can reach 90%. At present, the SOEC mainly adopts oxygen ion conductors as electrolytes, and needs to be operated at a high temperature of 750 DEG C or above to show excellent performance. However, high-temperature operation also causes a series of problems, including poor cell stability, high preparation cost and the like.

[0003] In recent years, a proton conductor electrolytic cell has attracted widespread attention. The proton conduction activation energy is 0.3-0.5 eV, which is lower than the oxygen ion conduction activation energy (0.8-0.9 eV), so that the proton conduction type SOEC is expected to maintain high performance at an operating temperature of 400-600 DEG C. However, the actual proton conduction 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 mainly due to the fact that BaO and Y2O3 and the like are precipitated at the electrolyte interface during the sintering process of the Ba(Ce,Zr)O3-based electrolyte material at a temperature of 1400 DEG C or above, which increases the grain boundary resistance and also causes the interfacial resistance between the electrolyte and the oxygen electrode to increase. In addition, the proton conductor electrolyte also has a certain electronic conductivity, which increases the internal leakage current of the electrolytic cell and reduces the electrolysis efficiency. Therefore, how to improve the ionic conductivity of the electrolyte membrane and improve the interface contact between the electrolyte and the electrode is a research hotspot in the field. SUMMARY

[0004] Based on the above technical background, the present application provides a proton conductor electrolytic cell composite membrane, a membrane electrode and a preparation method, which solves the technical problem that BaO and Y2O3 are precipitated on the surface interface of the proton conductor electrolyte after the membrane electrode two-in-one of the nickel oxide and the proton conductor-based composite anode / proton conductor-based electrolyte is sintered at a high temperature, resulting in a decrease in the proton conductivity.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] In a first aspect, the present application provides a proton conductor electrolytic cell composite membrane, which is composed of a proton conductor-based electrolyte layer, a zirconia-based electrolyte membrane layer and a ceria-based electrolyte membrane layer which are sequentially and closely connected.

[0007] The material of the proton conductor-based electrolyte layer is BaZr 1-z N zO3, wherein N is one or more of Y, Ce, Yb, Sc, Gd, La, Sm, Pr, and 0.01≤z<1; the material of the zirconia-based electrolyte film layer is M y Zr 1-y O2, wherein M is one of Y, Ce, Yb, Sc, Gd, La, Sm, Pr, and 0.01≤y≤0.5; the material of the ceria-based electrolyte film layer is Ln x Ce 1-x O2, wherein Ln is one of Y, Ce, Yb, Sc, Gd, La, Sm, Pr, and 0.01≤x≤0.5.

[0008] Further, in the above technical solution, the M and the N are the same element.

[0009] Further, in the above technical solution, the thickness of the zirconia-based electrolyte film layer is 0.01-50 microns.

[0010] Further, in the above technical solution, the thickness of the ceria-based electrolyte film layer is 0.02-300 microns.

[0011] Preferably, the thickness of the zirconia-based electrolyte film layer is 0.05-5 microns, and the thickness of the ceria-based electrolyte film layer is 0.1-10 microns.

[0012] Further, in the above technical solution, the density of the zirconia-based electrolyte film layer and the ceria-based electrolyte film layer is ≥95%.

[0013] In a second aspect, the application provides a method for preparing a proton conductor electrolytic cell composite film, which comprises: preparing a zirconia-based electrolyte film layer on a proton conductor-based electrolyte layer by sputtering; and preparing a ceria-based electrolyte film layer on the zirconia-based electrolyte film layer by sputtering.

[0014] Further, in the above technical solution, when the zirconia-based electrolyte film layer is prepared by sputtering, the sputtering gas pressure is 0.5-0.6 Pa, the sputtering power density is 20-30 W / cm 2 , the ratio of oxygen flow rate to argon flow rate is 1:10-12, and the sputtering substrate temperature is 500-550℃, followed by annealing at 1300-1350℃ for 10-12 h;

[0015] Further, in the above technical solution, when the ceria-based electrolyte film layer is prepared by sputtering, the sputtering gas pressure is 0.5-0.6 Pa, the sputtering power density is 20-30 W / cm 2 , the ratio of oxygen flow rate to argon flow rate is 1:10-12, and the sputtering substrate temperature is 500-550℃, followed by annealing at 900-950℃ for 2-3 h.

[0016] Thirdly, the present invention provides a membrane electrode in which an oxygen electrode material is coated on the cerium oxide-based electrolyte membrane layer of the proton conductor electrolytic cell composite membrane to obtain the membrane electrode.

[0017] Furthermore, in the above technical solution, the operating temperature of the membrane electrode is 300–600°C.

[0018] Beneficial effects:

[0019] (1) After high-temperature sintering, the membrane electrode assembly of the nickel oxide and proton conductor-based composite anode / proton conductor-based electrolyte exhibits BaO and Y2O3 precipitation at the proton conductor electrolyte surface interface, leading to a decrease in proton conductivity. The proton conductor electrolyzer composite membrane of this invention comprises a proton conductor-based electrolyte layer, a zirconium oxide-based electrolyte layer tightly connected to the proton conductor-based electrolyte layer, and a cerium oxide-based electrolyte layer tightly connected to the zirconium oxide-based electrolyte layer. The zirconium oxide-based electrolyte tightly connected to the proton conductor-based electrolyte reacts with the BaO and Y2O3 precipitated on the surface of the proton conductor electrolyte through high-temperature annealing to form Ba(Zr,Y)O3, thereby improving the proton conductivity of the composite membrane.

[0020] (2) The proton conductor electrolytic cell is an ion-electron hybrid conductor. When used as an electrolyte in an electrolytic cell, the high electrolysis voltage leads to increased internal leakage current. In the proton conductor electrolytic cell composite membrane of the present invention, the addition of zirconium oxide-based electrolyte membrane and cerium oxide-based electrolyte membrane effectively blocks electron transfer in the composite membrane, thereby improving the efficiency of the electrolytic cell.

[0021] (3) In the proton conductor electrolytic cell composite membrane of the present invention, the cerium oxide-based electrolyte membrane has good compatibility with the currently highly active oxygen electrode material, which improves the interfacial contact between the composite electrolyte membrane and the oxygen electrode and improves the electrolysis performance.

[0022] (4) In this invention, the zirconium oxide-based electrolyte and the cerium oxide-based electrolyte membrane interact under the operating conditions of the electrolyzer, increasing the active sites on the interface that catalyze the dissociation of water molecules and improving the performance of the electrolyzer. Detailed Implementation

[0023] To better explain and facilitate understanding of the present invention, the present invention will be described in detail below through specific embodiments.

[0024] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below. It should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the invention to those skilled in the art.

[0025] Comparative Example 1

[0026] NiO-BaZr prepared by dry pressing method 0.8 Y 0.2 O3 / / BaZr 0.8 Y 0.2 O3 membrane electrode combined.

[0027] Mix 12g of NiO and 8g of BaZr 0.8 Y 0.2 O3 was thoroughly mixed and ground in an agate mortar for about 2 hours, and then set aside. 1g of the above mixed powder was weighed and placed into a cylindrical stainless steel mold with a diameter of 25mm. The mold was then pressed into a sheet using a hydraulic press at 128MPa to obtain the anode substrate. One side of the mold was opened, and 0.05g of BaZr was evenly added to the anode substrate. 0.8 Y 0.2 O3 fluffy powder was pressed under a pressure of 256 MPa. The pressed blank was removed from the mold and calcined at 1500℃ for 4 hours in an air atmosphere in a high-temperature furnace to obtain NiO-BaZr. 0.8 Y 0.2 O3 / / BaZr 0.8 Y 0.2 O3 membrane electrode assembly. 0.8 Y 0.2 The surface of the O3 electrolyte membrane is coated with 0.005g of Ba. 0.5 Sr 0.5 Co 0.2 Fe 0.8 An O3 oxygen electrode was formed and sintered at 950℃ for 2 hours to create a complete film electrode, wherein the effective area of ​​the oxygen electrode is 0.5 cm². 2 The oxygen electrode is 30 micrometers thick.

[0028] The above-mentioned membrane electrode was subjected to water vapor electrolysis testing at a temperature of 600℃, an inlet air humidity of 50% AH, an OCV of 0.9348V, and an electrolysis current density of 1.14 Acm at 1.3V. -2 .

[0029] Example 1

[0030] In proton conductor-based electrolyte BaZr 0.8 Y 0.2 A 10-micron-thick zirconium oxide-based electrolyte Y was prepared by sputtering on O3. 0.15 Zr 0.85 O2, sputtering pressure 0.5 Pa, sputtering power density P = 30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and then annealed at 1300℃ for 10 hours. 0.15 Zr 0.85The O2 density reaches 98%. Then, in the zirconium oxide-based electrolyte Y... 0.15 Zr 0.85 200-micrometer-thick cerium oxide-based electrolyte Gd was prepared by sputtering on O2. 0.1 Ce 0.9 O2 film, sputtering pressure 0.5 Pa, sputtering power density P = 20–30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and the cerium oxide-based electrolyte was annealed at 900℃ for 2 hours. 0.1 Ce 0.9 The O2 film density reached 98%. 0.005 g of Ba was coated onto the surface of the cerium oxide-based electrolyte membrane. 0.5 Sr 0.5 Co 0.2 Fe 0.8 An O3 oxygen electrode was formed and sintered at 950℃ for 2 hours to create a complete film electrode, wherein the effective area of ​​the oxygen electrode is 0.5 cm². 2 The oxygen electrode is 30 micrometers thick.

[0031] The above-mentioned membrane electrode was subjected to water vapor electrolysis testing at a temperature of 600℃, an inlet air humidity of 50% AH, an OCV of 0.9548V, and an electrolysis current density of 2.5Acm at 1.3V. -2 .

[0032] Example 2

[0033] In proton conductor-based electrolyte BaZr 0.8 Y 0.2 0.05 μm thick zirconia-based electrolyte Y was prepared by sputtering on O3. 0.15 Zr 0.85 O2, sputtering pressure 0.5 Pa, sputtering power density P = 30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and then annealed at 1300℃ for 10 hours. 0.15 Zr 0.85 The O2 density reaches 98%. Then, in the zirconium oxide-based electrolyte Y... 0.15 Zr 0.85 Preparation of 0.5 μm thick cerium oxide-based electrolyte Gd by sputtering on O2 0.1 Ce 0.9 O2 film, sputtering pressure 0.5 Pa, sputtering power density P = 20–30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and the cerium oxide-based electrolyte was annealed at 900℃ for 2 hours. 0.1 Ce 0.9The O2 film density reached 98%. 0.005 g of Ba was coated onto the surface of the cerium oxide-based electrolyte membrane. 0.5 Sr 0.5 Co 0.2 Fe 0.8 An O3 oxygen electrode was formed and sintered at 950℃ for 2 hours to create a complete film electrode, wherein the effective area of ​​the oxygen electrode is 0.5 cm². 2 The oxygen electrode is 30 micrometers thick.

[0034] The above-mentioned membrane electrode was subjected to water vapor electrolysis testing at a temperature of 600℃, an inlet air humidity of 50% AH, an OCV of 0.9565V, and an electrolysis current density of 2.97 Acm at 1.3V. -2 .

[0035] Example 3

[0036] In proton conductor-based electrolyte BaZr 0.4 Ce 0.4 Y 0.2 0.05 μm thick zirconia-based electrolyte Y was prepared by sputtering on O3. 0.15 Ce 0.05 Zr 0.8 O2, sputtering pressure 0.5 Pa, sputtering power density P = 30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and then annealed at 1300℃ for 10 hours. 0.15 Ce 0.05 Zr 0.8 The O2 density reaches 98%. Then, in the zirconium oxide-based electrolyte Y... 0.15 Zr 0.85 Preparation of 0.5 μm thick cerium oxide-based electrolyte Gd by sputtering on O2 0.1 Ce 0.9 O2 film, sputtering pressure 0.5 Pa, sputtering power density P = 20–30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and the cerium oxide-based electrolyte was annealed at 900℃ for 2 hours. 0.1 Ce 0.9 The O2 film density reached 98%. 0.005 g of Ba was coated onto the surface of the cerium oxide-based electrolyte membrane. 0.5 Sr 0.5 Co 0.2 Fe 0.8 An O3 oxygen electrode was formed and sintered at 950℃ for 2 hours to create a complete film electrode, wherein the effective area of ​​the oxygen electrode is 0.5 cm². 2 The oxygen electrode is 30 micrometers thick.

[0037] The above-mentioned membrane electrode was subjected to water vapor electrolysis testing at a temperature of 600℃, an inlet air humidity of 50% AH, an OCV of 0.9555V, and an electrolysis current density of 2.86 Acm at 1.3V. -2 .

[0038] Example 4

[0039] In proton conductor-based electrolyte BaZr 0.4 Ce 0.4 Sc 0.2 0.05 μm thick zirconia-based electrolyte Sc was prepared by sputtering on O3. 0.15 Ce 0.05 Zr 0.8 O2, sputtering pressure 0.5 Pa, sputtering power density P = 30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtered substrate temperature was 500℃, and then annealed at 1300℃ for 10 hours. 0.15 Ce 0.05 Zr 0.8 The O2 density reaches 98%. Then, in the zirconium oxide-based electrolyte Sc... 0.15 Ce 0.05 Zr 0.8 Preparation of 0.5 μm thick cerium oxide-based electrolyte Sm by sputtering on O2 0.2 Ce 0.8 O2 film, sputtering pressure 0.5 Pa, sputtering power density P = 20–30 W / cm³ 2 The oxygen flow rate to argon flow rate ratio was 1 / 10, the sputtering substrate temperature was 500℃, and the cerium oxide-based electrolyte was annealed at 900℃ for 2 hours. 0.2 Ce 0.8 The O2 film density reached 98%. 0.005 g of Ba was coated onto the surface of the cerium oxide-based electrolyte membrane. 0.5 Sr 0.5 Co 0.2 Fe 0.8 An O3 oxygen electrode was formed and sintered at 950℃ for 2 hours to create a complete film electrode, wherein the effective area of ​​the oxygen electrode is 0.5 cm². 2 The oxygen electrode is 30 micrometers thick.

[0040] The above-mentioned membrane electrode was subjected to water vapor electrolysis testing at a temperature of 600℃, an inlet air humidity of 50% AH, an OCV of 0.9525V, and an electrolysis current density of 2.46 Acm at 1.3V. -2 .

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite membrane for a proton conductor electrolytic cell, characterized in that: The proton conductor electrolytic cell composite membrane is composed of a proton conductor-based electrolyte layer, a zirconium oxide-based electrolyte membrane layer, and a cerium oxide-based electrolyte membrane layer connected in sequence. The material of the proton conductor-based electrolyte layer is BaZr. 1-z N z O3, where N is one of Y, Ce, Yb, Sc, Gd, La, Sm, and Pr, and 0.01 ≤ z < 1; the material of the zirconium oxide-based electrolyte membrane is M. y Zr 1-y O2, where M is one of Y, Ce, Yb, Sc, Gd, La, Sm, and Pr, and 0.01 ≤ y ≤ 0.5; the material of the cerium oxide-based electrolyte membrane is Ln. x Ce 1-x O2, where Ln is one of Y, Ce, Yb, Sc, Gd, La, Sm, and Pr, and 0.01≤x≤0.5; M and N are the same element.

2. The proton conductor electrolytic cell composite membrane according to claim 1, characterized in that: The thickness of the zirconium oxide-based electrolyte membrane is 0.01~50 micrometers.

3. The proton conductor electrolytic cell composite membrane according to claim 1, characterized in that: The thickness of the cerium oxide-based electrolyte membrane is 0.02~300 micrometers.

4. The proton conductor electrolytic cell composite membrane according to claim 1, characterized in that: The density of both the zirconium oxide-based electrolyte membrane and the cerium oxide-based electrolyte membrane is ≥95%.

5. The method for preparing the proton conductor electrolytic cell composite membrane according to any one of claims 1-4, characterized in that: A zirconia-based electrolyte film is prepared by sputtering on a proton conductor-based electrolyte layer, and then a cerium oxide-based electrolyte film is prepared by sputtering on the zirconia-based electrolyte film.

6. The preparation method according to claim 5, characterized in that: When preparing zirconia-based electrolyte films using sputtering, the sputtering pressure is 0.5–0.6 Pa and the sputtering power density is 20–30 W / cm². 2 The ratio of oxygen flow rate to argon flow rate is 1:10~12, the sputtering substrate temperature is 500~550℃, and then annealing is carried out at 1300~1350℃ for 10~12h; When preparing cerium oxide-based electrolyte films using sputtering, the sputtering pressure is 0.5–0.6 Pa and the sputtering power density is 20–30 W / cm². 2 The oxygen flow rate to argon flow rate ratio is 1:10~12, the sputtering substrate temperature is 500~550℃, and then annealing is performed at 900~950℃ for 2~3 hours.

7. A membrane electrode, characterized in that: An oxygen electrode material is coated on the cerium oxide-based electrolyte membrane layer of the proton conductor electrolytic cell composite membrane according to any one of claims 1-4 to obtain a membrane electrode.

8. The membrane electrode according to claim 7, characterized in that: The operating temperature of the membrane electrode is 300~600℃.