A method for the production of a porous electrode-supported solid oxide proton conductor electrolyte film by low-pressure dip coating

Abstract

The application discloses a method for preparing a porous electrode supported solid oxide proton conductor electrolyte film by low-pressure dip coating, which comprises the following steps: firstly, pre-sintering a porous electrode support layer; then, hanging the porous electrode support layer in prepared electrolyte slurry; and finally, lowering the gas pressure in a container to promote gas removal of the porous support layer, so that the electrolyte slurry is firmly adsorbed on the surface of the support layer to prepare a uniformly coated proton conductor electrolyte film. The method is simple to operate and is widely applicable to the preparation of various electrolyte films in the field of fuel cells / electrolytic cells. The solid oxide proton conductor electrolyte film prepared by the method has high repeatability and excellent performance, and is suitable for industrial amplification.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide fuel cells / electrolytes, and specifically relates to a method for preparing a solid oxide subconductor electrolyte film, particularly a method for preparing a porous electrode-supported solid oxide subconductor electrolyte film by low-pressure dip coating. Background Technology

[0002] Proton-conducting ceramic batteries (PCCs, including proton-conducting fuel cells and proton-conducting electrolyzers) have attracted increasing attention over the past four decades, enabling the interconversion of renewable electrical energy and hydrogen in a single electrochemical device through fuel cell and electrolysis modes. Compared to solid oxide batteries (SOCs, including SOFCs and SOECs) operating at temperatures above 750°C, PCCs exhibit lower proton conduction activation energies and can operate in a lower temperature range (400-600°C), which helps to slow corrosion rates and reduce equipment costs. However, the development of PCCs lags far behind that of SOCs due to limitations in the stability and proton conductivity of solid oxide proton-conducting electrolyte materials. Therefore, to improve the performance of PCCs, various advanced electrolyte materials have been developed, such as yttrium and ytterbium co-doped barium zirconate solid solution ceramic (BCZYYb4411), a perovskite proton-conducting electrolyte with good proton conductivity and chemical stability.

[0003] As is well known, the overall ohmic resistance of a battery is mainly affected by the ohmic resistance of the electrolyte layer. The thinner the electrolyte layer, the lower the overall ohmic resistance of the battery. Therefore, to obtain high-performance solid oxide proton conductor ceramic batteries, various techniques have been developed to prepare electrolyte structures with porous electrode supports and a thickness of less than 30 μm. The first type of method is dry pressing and co-pressing processes, which have the advantages of requiring the fewest steps and having the cheapest equipment, but they suffer from poor reproducibility and difficulty in preparing thin and flat electrolyte layers with uniform thickness. The second type of method for manufacturing thin and dense electrolyte layers is based on plasma or laser techniques, such as thermal sputtering, thermal spraying, and pulsed laser deposition. However, these techniques require specialized and expensive equipment, which is not economically friendly for researchers wishing to participate in small research groups in the field of proton conductor ceramics. They not only lack industrial application value but also hinder the development of basic research in this direction. The third type is wet chemical methods, such as casting, blade coating, dip coating, drop coating, and spin coating. Currently, the most commonly used method by researchers is dip-coating. However, bubbles emerging and bursting from the porous electrode support layer can easily lead to defects such as cracks, pores / pinholes in the electrolyte thin layer, resulting in fuel gas leakage, short circuits during PCFC / PCEC electrical testing, and low OCV values. This leads to low battery fabrication success rates and poor reproducibility. These factors collectively limit the fabrication of solid oxide proton conductor ceramic batteries and, to some extent, restrict the industrial application of proton conductor ceramics. Summary of the Invention

[0004] The purpose of this invention is to provide a method for preparing porous electrode-supported solid oxide subconductor electrolyte films by low-pressure dip coating of electrolyte slurry. The method involved in this invention is simple to operate and widely applicable to the preparation of various electrolyte thin films in the field of fuel cells / electrolytes. Single cells prepared based on the solid oxide subconductor electrolyte films prepared by the method of this invention have high repeatability and excellent performance, and are suitable for industrial scale-up.

[0005] To achieve the above objectives, this invention provides a method for preparing a porous electrode-supported solid oxide proton conductor electrolyte film using low-pressure dip coating. The method involves first pre-firing a porous electrode support layer, then suspending it in a prepared electrolyte slurry, and finally reducing the gas pressure inside the container to promote gas removal from the porous support layer. This allows the electrolyte slurry to firmly adhere to the surface of the support layer, resulting in a uniformly coated proton conductor electrolyte film. The main steps are as follows:

[0006] (1) Fabrication of porous electrode support layer

[0007] First, calculate the required mass of raw material powder for the solid oxide subconductor electrolyte powder according to the stoichiometric ratio. Mix the electrolyte raw material powder, nickel oxide, and 8-30μm spherical graphite or starch pore-forming agent in a ball mill jar at a weight ratio of electrolyte powder a% : nickel oxide b% : spherical graphite or starch pore-forming agent c%, adding an appropriate amount of anhydrous ethanol or isobutanol as a solvent to form a paste. The paste should consist of a = 25-40, b = 40-65, and c = 10-20. Then, place the paste in a ball mill and mill at 1800-600 rpm for 2-48 hours. Next, remove the powder and dry it in an oven at 75-120℃ for 3-12 hours. Add an appropriate amount of PVA to the dried anode mixed powder, stirring until it forms a dry paste. Dry and grind the paste. Then, use a tablet press to compress the solid oxide subconductor electrode support layer. Pour the ball-milled electrolyte powder into a mold and hold it under pressure at 200-388 MPa for 1-3 minutes to form the support electrode sheet. The pressed support layer containing the pore-forming agent is placed in a muffle furnace and pre-fired at 800-1200℃ for 2-5 hours to form a porous electrode support layer (porous hydrogen electrode support layer).

[0008] (2) Low-pressure dip-coated proton conductor electrolyte film

[0009] First, calculate the required mass of raw material powder for the electrolyte powder according to the stoichiometric ratio. Place the proton conductor electrolyte raw material powder into a ball mill jar, add an appropriate amount of anhydrous ethanol as a solvent, and ball mill at 180-250 rpm for 2-48 hours. Then, remove the powder and dry it in an oven at 75-120℃ for 3-12 hours. Then, the electrolyte powder is mixed with an appropriate amount of triethanolamine (dispersant), anhydrous ethanol (solvent), and methyl ethyl ketone (methyl ethyl ketone) and ball-milled at 180-250 rpm for 2-24 hours. After that, an appropriate amount of butyl benzyl phthalate (plasticizer) and an appropriate amount of polyvinyl butyral (PVB, binder) are added to the ball milling jar and ball-milled for another 2-24 hours to obtain the prepared electrolyte powder slurry. The mass percentage of each component in the prepared electrolyte powder slurry is as follows: electrolyte powder 5.5-23%, triethanolamine 1-3%, anhydrous ethanol 50-60%, methyl ethyl ketone 20-30%, butyl benzyl phthalate 3-5%, and polyvinyl butyral 3-5%. The electrolyte slurry is poured into a container, and the porous hydrogen electrode support layer pre-fired in step (1) is suspended in the electrolyte slurry and the rubber stopper is closed. Then, the pressure inside the bottle is controlled at -0.04 to -0.06 MPa using a vacuum circulating water pump and two shut-off valves. The coating is continuously applied for 0.5 to 3 minutes. The vacuum circulating water pump is then disconnected, the shut-off valve at the container opening is closed, and the pressure is maintained for 1 to 3 minutes. Afterward, the sheet is removed and air-dried or dried in an oven at 60-100°C to obtain a proton conductor film coated with electrolyte layers on both sides. Subsequently, it is calcined in a high-temperature muffle furnace at 1400-1500°C for 5-18 hours. The bottom of the half-cell is then thinned by grinding to obtain a porous electrode-supported solid oxide proton conductor electrolyte film, which can be used as a half-cell in the preparation of fuel cells / electrolytes.

[0010] The porous hydrogen electrode-supported solid oxide proton conductor electrolyte film prepared by the method of this invention is dense, non-perforated, and has an adjustable thickness. It has high proton conductivity, low ohmic resistance, and good repeatability. Single cells prepared based on the porous hydrogen electrode-supported solid oxide proton conductor electrolyte film prepared by this invention have stable constant current discharge performance and are suitable for industrial scale-up.

[0011] The solid oxide sub-conductor electrolyte half-cell prepared using the present invention was tested by SEM and found to have no defects such as perforations or cracks on the dense electrolyte thin layer surface.

[0012] The solid oxide electrolyte conductor fuel cell prepared using this invention was used in hydrogen-oxygen fuel cell testing. Results showed that when the prepared electrolyte layer was only 10 μm thick, it could achieve 741, 522, and 357 mW / cm² at 650, 600, and 550 °C, respectively. -2 The power density corresponds to polarization resistances of only 0.047, 0.115, and 0.312 Ωcm.-2 Furthermore, at 600℃, the current density is 200 mA cm⁻¹. -2 The single cell has a stability of over 250 hours.

[0013] Compared with methods reported at home and abroad, the hydrogen electrode-supported proton conductor electrolyte thin film prepared by the present invention has the advantages of simple operation, no need for expensive equipment, high film formation repeatability, strong connection with the supporting electrode, excellent performance, and suitability for industrial scale-up.

[0014] Compared with the conventional atmospheric pressure dip coating method, the present invention has the following advantages: (1) The present invention reduces the gas pressure inside the container and generates a pressure difference inside and outside the porous support layer electrode, thereby fully removing the gas near the surface of the porous support layer, thereby generating capillary force, so that the electrolyte slurry can be more firmly and uniformly adsorbed on the surface of the porous support layer, forming a bonded, continuous and uniform electrolyte film. At the same time, the stronger adsorption force can prevent the electrolyte from separating from the electrode during the battery test; (2) The present invention is fully applicable to the preparation of various regular or irregular shaped supported proton conductor electrolyte films, so it is suitable for industrial scale-up and has high industrial application value; (3) The present invention is simple to operate and does not require other expensive instruments and equipment; (4) The electrolyte film prepared by the present invention has no through holes on the surface, which can prevent the gas from contacting each other and causing a short circuit during the single cell test; (5) The supported proton conductor electrolyte film prepared by the present invention has high repeatability and excellent battery test performance, and is suitable for industrial scale-up. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the negative pressure dip coating process of the present invention, wherein 1-circulating water vacuum pump, 2-three-way valve, 3-stop valve, 4-container, and 5-electrolyte slurry.

[0016] Figure 2 The images show scanning electron microscope (SEM) images of the cross-section (right) and surface (left) of the fuel cell prepared using the present invention in Example 6.

[0017] Figure 3 The test diagrams for hydrogen-oxygen fuel cells in Examples 2-7 are shown.

[0018] Figure 4 This is a graph from the constant current stability test in Example 3. Detailed Implementation

[0019] The following embodiments will further illustrate the present invention, but are not intended to limit the invention.

[0020] Example 1

[0021] Step 1: Fabrication of a porous electrode support layer

[0022] Weigh BaCe 0.6 Zr 0.3 Y 0.1 O 3-δ Electrolyte raw material powder, comprising 200g BaCO3, 172g CeO2, 37g ZrO2, and 11.3g Y2O3, along with 460g nickel oxide powder and 85g 8μm spherical graphite, was placed together in a ball mill jar. An appropriate amount of anhydrous ethanol was added as a solvent to mix the powders into a paste. The mixture was then placed in a ball mill and milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90℃ for 5 hours. The dried anode mixed powder was mixed with an appropriate amount of PVA, stirred until it reached a dry paste state, and then dried and ground. The ball-milled electrolyte powder was then poured into a mold and pressed at 250MPa for 1 minute. The pressed support layer containing a pore-forming agent was placed in a muffle furnace and pre-fired at 1000℃ for 2 hours to form a porous electrode support layer.

[0023] Step 2: Low-pressure dip coating of BaCe 0.6 Zr 0.3 Y 0.1 O 3-δ Proton conductor electrolyte thin film

[0024] Weigh BaCe 0.6 Zr 0.3 Y 0.1 O 3-δ Electrolyte raw material powder was placed in a ball mill jar containing 200g BaCO3, 172g CeO2, 37g ZrO2, and 11.3g Y2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 24 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 9g of the electrolyte powder was mixed with 0.3g triethanolamine, 20mL anhydrous ethanol, and 20mL butanone, and then ball-milled at 200 rpm for 48 hours. Subsequently, 5g of butyl benzyl phthalate and 5g of polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled for another 48 hours to obtain the prepared electrolyte powder slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. The pressure inside the bottle was then controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried, resulting in a half-cell coated with electrolyte films on both sides. This was then calcined in a high-temperature muffle furnace at 1400°C for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. The cross-sectional thickness was then characterized using electron microscopy.

[0025] Example 2

[0026] Step 1: Fabrication of a porous electrode support layer

[0027] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Electrolyte raw material powder, comprising 255.18 g BaCO3, 89 g CeO2, 63.74 g ZrO2, 14.6 g Y2O3, and 25.48 g Yb2O3, along with 672 g nickel oxide powder and 280 g 8 μm spherical graphite, was placed together in a ball mill jar. An appropriate amount of anhydrous ethanol was added as a solvent to mix the powders into a paste. The mixture was then placed in a ball mill and milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. The dried anode mixed powder was mixed with an appropriate amount of PVA, stirred until it reached a dry paste state, and then dried and ground. The ball-milled electrolyte powder was then poured into a mold and pressed at 250 MPa for 1 minute. The pressed support layer containing a pore-forming agent was placed in a muffle furnace and pre-fired at 1000°C for 2 hours to form a porous electrode support layer.

[0028] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Proton conductor electrolyte thin film

[0029] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δElectrolyte raw material powder was placed in a ball mill jar containing 255.18g BaCO3, 89g CeO2, 63.74g ZrO2, 14.6g Y2O3, and 25.48g Yb2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 6g of the electrolyte powder was mixed with 1.2g triethanolamine, 60mL anhydrous ethanol, and 60mL butanone, and ball-milled at 200 rpm for 48 hours. Then, 15g of butyl benzyl phthalate and 15g of polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled for another 48 hours to obtain the prepared electrolyte powder slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. Then, the pressure inside the bottle was controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried to obtain a half-cell with electrolyte films coated on both sides. Subsequently, it was calcined in a high-temperature muffle furnace at 1450℃ for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. The cross-sectional thickness was then characterized by electron microscopy, and BaCo was coated onto the electrolyte. 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ Electrode testing of the ohmic resistance of a single cell.

[0030] Example 3

[0031] Step 1: Prepare a porous electrode support layer, as in Step 1 of Example 2.

[0032] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Proton conductor electrolyte thin film

[0033] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δElectrolyte raw material powder was placed in a ball mill jar containing 255.18g BaCO3, 89g CeO2, 63.74g ZrO2, 14.6g Y2O3, and 25.48g Yb2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 11g of the electrolyte powder was mixed with 0.3g triethanolamine, 20mL anhydrous ethanol, and 20mL butanone, and ball-milled for 48 hours. Then, 5g butyl benzyl phthalate and 5g polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled again at 200 rpm for 48 hours to obtain the prepared electrolyte slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. Then, the pressure inside the bottle was controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried to obtain a half-cell coated with electrolyte films on both sides. Subsequently, it was calcined in a high-temperature muffle furnace at 1450℃ for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. Electron microscopy was then used to characterize the cross-sectional thickness to 10 μm, and a BCFZY electrode was coated on the electrolyte to test the ohmic resistance of the single cell, followed by a 200 mA / cm² test. -2 Constant current stability test.

[0034] Example 4

[0035] Step 1: Prepare a porous electrode support layer, as in Step 1 of Example 2.

[0036] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Proton conductor electrolyte thin film

[0037] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δElectrolyte raw material powder was placed in a ball mill jar containing 255.18g BaCO3, 89g CeO2, 63.74g ZrO2, 14.6g Y2O3, and 25.48g Yb2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 17g of the electrolyte powder was mixed with 0.3g triethanolamine, 20mL anhydrous ethanol, and 20mL butanone, and ball-milled at 200 rpm for 48 hours. Then, 5g of butyl benzyl phthalate and 5g of polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled for another 48 hours to obtain the prepared electrolyte powder slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. The pressure inside the bottle was then controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried, resulting in a half-cell with electrolyte thin layers coated on both sides. This was then calcined in a high-temperature muffle furnace at 1450°C for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. The cross-sectional thickness morphology was characterized using electron microscopy, and a BCFZY electrode was coated onto the electrolyte to test the ohmic resistance of the single cell.

[0038] Example 5

[0039] Step 1: Prepare a porous electrode support layer, as in Step 1 of Example 2.

[0040] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Proton conductor electrolyte thin film

[0041] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δElectrolyte raw material powder was placed in a ball mill jar containing 255.18g BaCO3, 89g CeO2, 63.74g ZrO2, 14.6g Y2O3, and 25.48g Yb2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 25g of the electrolyte powder was mixed with 0.3g triethanolamine, 20mL anhydrous ethanol, and 20mL butanone, and ball-milled at 200 rpm for 48 hours. Then, 5g of butyl benzyl phthalate and 5g of polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled for another 48 hours to obtain the prepared electrolyte powder slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. The pressure inside the bottle was then controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried, resulting in a half-cell coated with electrolyte films on both sides. This was then calcined in a high-temperature muffle furnace at 1450°C for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. The cross-sectional thickness morphology was characterized using electron microscopy, and a BCFZY electrode was coated onto the electrolyte to test the ohmic resistance of the single cell.

[0042] Example 6

[0043] Step 1: Prepare a porous electrode support layer, as in Step 1 of Example 2.

[0044] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Proton conductor electrolyte thin film

[0045] Weigh BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δElectrolyte raw material powder was placed in a ball mill jar containing 255.18g BaCO3, 89g CeO2, 63.74g ZrO2, 14.6g Y2O3, and 25.48g Yb2O3, with an appropriate amount of anhydrous ethanol added as a solvent. The mixture was then ball-milled at 200 rpm for 48 hours. The powder was then removed and dried in an oven at 90°C for 5 hours. Next, 36g of the electrolyte powder was mixed with 0.3g triethanolamine, 20mL anhydrous ethanol, and 20mL butanone, and ball-milled for 48 hours. Then, 5g of butyl benzyl phthalate and 5g of polyvinyl butyral were added to the ball mill jar, and the mixture was ball-milled again at 200 rpm for 48 hours to obtain the prepared electrolyte powder slurry. The electrolyte slurry was poured into a container, and a pre-fired porous hydrogen electrode support layer was suspended in the slurry. The container was then sealed with a rubber stopper. Then, the pressure inside the bottle was controlled to -0.05 MPa using a vacuum circulating water pump and two shut-off valves. The coating was continued for 1 minute, then the vacuum circulating water pump was disconnected, the shut-off valve at the container opening was closed, and the pressure was maintained for 2 minutes. The sheet was then removed and air-dried to obtain a half-cell with electrolyte thin layers coated on both sides. Subsequently, it was calcined in a high-temperature muffle furnace at 1450℃ for 18 hours. The bottom of the half-cell was then thinned by grinding to obtain a half-cell suitable for use in proton conductor electrolyte fuel cells / electrolytes. The cross-sectional thickness morphology was then characterized by electron microscopy, and the results are as follows: Figure 2 As shown. The electrolyte density was measured to be 98% using the Archimedes method. The ohmic resistance of a single cell was tested by scraping a BCFZY electrode onto the electrolyte.

[0046] Example 7

[0047] The electrolyte thickness of the proton-conducting electrolyte half-cells prepared in Examples 1, 2, 3, 4, 5, and 6 was observed using a scanning electron microscope. BCFZY air electrodes were coated and incubated at 650°C with hydrogen gas (3% H₂O + 97% hydrogen, 20 mL / min). -1 ) as fuel, using air (100mL min) -1 Using ) as the oxidant, the ohmic resistance of a single cell was tested, and the results are shown in Table 1:

[0048] Table 1. Thickness and Ohmic Resistance of Low-Voltage Dip-Coated Proton Conductor Electrolyte Film

[0049]

[0050]

[0051] As can be seen from the table, electrolyte thin layers of different thicknesses can be accurately prepared by adjusting the proportion of electrolyte powder in the slurry formulation, and the quality of electrolyte powder maintains a good linear relationship with the thickness of electrolyte layer and ohmic resistance.

[0052] When the electrolyte thin film prepared in Example 3 was only 10 μm thick, it could achieve 741, 522, and 357 mW / cm² at 650, 600, and 550 °C, respectively. -2 The power density corresponds to polarization resistances of only 0.047, 0.115, and 0.312 Ωcm. -2 Furthermore, at 600℃, the current density is 200 mA cm⁻¹. -2 The single cell exhibits stability exceeding 250 hours (see...). Figure 4 ).

[0053] Example 8: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ Repeatability experiment of proton conductor electrolyte thin film

[0054] Step 1: Prepare a porous electrode support layer, as in Step 1 of Example 2.

[0055] Step 2: Low-pressure dip coating of BaCe 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ The proton conductor electrolyte film is processed in step 2 of Example 3.

[0056] Step 3: Repeat steps 1 and 2 three times to prepare three batches of low-pressure dip-coated BaCe. 0.4 Zr 0.4 Y 0.1 Yb 0.1 O 3-δ A proton-conducting electrolyte film (repeated steps 1 and 2 once, denoted as 8-1; repeated steps 1 and 2 twice, denoted as 8-2; repeated steps 1 and 2 three times, denoted as 8-3) was coated with a BCFZY air electrode. The electrochemical performance of a single cell was tested at 650°C using hydrogen as fuel and air as the oxidant. The results are shown in Table 2.

[0057] Table 2. Electrochemical performance at 650℃ after low-pressure dip-coated proton conductor electrolyte film is coated onto BCFZY air electrode

[0058]

[0059] As can be seen from the table, the three batches of proton conductor electrolyte films prepared by the low-pressure dip coating method showed very similar electrochemical performance after being fabricated into single cells by coating electrodes, indicating that the method has good reproducibility.

Claims

1. A method for the production of a porous electrode-supported solid oxide proton conductor electrolyte thin film by low pressure dip coating, characterized in that, The steps are as follows: (1) Preparation of porous electrode support layer First, calculate the required mass of raw material powder for the solid oxide electrolyte conductor powder according to the stoichiometric ratio. Mix the electrolyte raw material powder, nickel oxide, and spherical graphite or starch pore-forming agent at a mass percentage of 25-40% electrolyte powder, 40-65% nickel oxide, and 10-20% spherical graphite or starch pore-forming agent in a ball mill jar, and add anhydrous ethanol or isobutanol as a solvent to ball mill the powder until it is uniform. Then, remove the powder and dry it in an oven. Add PVA to the dried mixed powder, stir evenly, dry and grind it. Then, put the powder into a mold and press it into a support electrode sheet. Put the pressed support electrode sheet into a muffle furnace and pre-fire it to form a porous electrode support layer. (2) Low-pressure dip-coated solid oxide sub-conductor electrolyte film First, calculate the required mass of raw material powder for the solid oxide proton conductor electrolyte powder according to the stoichiometric ratio, place it in a ball mill jar, add anhydrous ethanol as a solvent, and ball mill until uniform. Then, remove the powder and dry it in an oven. Next, mix a certain amount of electrolyte powder with triethanolamine, anhydrous ethanol, and methyl ethyl ketone and ball mill until uniform. Then, continue to add butyl benzyl phthalate and polyvinyl butyral to the ball mill jar and continue ball milling until uniform, thus obtaining the prepared electrolyte powder slurry. After transferring the electrolyte slurry to a container, suspend the pre-fired porous electrode support layer in the electrolyte solution. Then, dip-coat for 0.5–3 min under a pressure of -0.04 to -0.06 MPa, and then hold the pressure for 0.5–3 min. After that, remove the sheet and air-dry it or place it in an oven to dry, thus obtaining the proton conductor film with the electrolyte thin layer. Finally, place it in a high-temperature muffle furnace for high-temperature calcination to obtain the porous electrode-supported solid oxide proton conductor electrolyte film.

2. The method according to claim 1, characterized in that In step (2), the mass percentage of each component in the electrolyte powder slurry is as follows: electrolyte powder 5.5-23%, triethanolamine 1-3%, anhydrous ethanol 50-60%, butanone 20-30%, butyl benzyl phthalate 3-5%, and polyvinyl butyral 3-5%.

3. The method of claim 1, wherein, In step (1), the ball milling speed is 180-600 rpm and the ball milling time is 2-48 h.

4. The method of claim 1, wherein, In step (1), the conditions for pressing into a support electrode sheet are: pressure of 200 – 388 MPa and time of 1 – 3 min.

5. The method according to claim 1 or 2, characterized in that, In step (2), the first ball milling speed is 180-250 rpm and the ball milling time is 24-48 h; the second ball milling speed is 180-250 rpm and the ball milling time is 2-24 h; the third ball milling speed is 180-250 rpm and the ball milling time is 2-24 h.

6. The method of claim 1, wherein, In step (1), the pre-firing conditions are: pre-firing at 800-1200℃ for 2-5 hours.

7. The method of claim 1, wherein In step (2), the conditions for high-temperature calcination are: calcination at 1400-1500℃ for 5-18 h.

8. The method of claim 1, wherein, In step (1), the particle size of the spherical graphite or starch powder is 8-30 μm.

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