A method for preparing an air electrode support type proton ceramic fuel cell

Abstract

This invention discloses a method for fabricating an air electrode-supported proton ceramic fuel cell. First, a phase inversion slurry is prepared by ball milling. Then, a BZCYYb support with through-pores is prepared using a phase inversion casting-spin-coating-impregnation technique. Next, an electrolyte layer is prepared using spin-coating. A NiO-BZCYYb composite fuel electrode is prepared using screen printing-sintering. Finally, an air electrode active material is impregnated to obtain an air electrode-supported proton ceramic fuel cell with a nanostructure and a regular, interconnected through-pore structure. This method can solve the problem of increased polarization resistance, avoid reaction between the air electrode and the electrolyte, and improve the conductivity of the electrolyte.

Description

Technical Field

[0001] This invention belongs to the field of fuel cell technology, specifically referring to a method for preparing an air electrode supported proton ceramic fuel cell. Background Technology

[0002] Solid oxide fuel cells (SOFCs) have attracted widespread attention due to their high energy conversion efficiency and low emissions. Based on different electrolyte ion conduction mechanisms, SOFCs can be divided into oxygen-ion-conducting SOFCs (O-SOFCs) and proton-conducting SOFCs (also known as proton ceramic fuel cells, PCFCs). O-SOFCs operate at higher temperatures, typically above 700°C, placing higher demands on various components and limiting their commercial development. PCFCs, on the other hand, can lower the operating temperature to below 700°C, resulting in easier sealing, better interfacial compatibility of battery components, higher thermal stability, and continued fuel flexibility. PCFCs can also be classified into electrolyte-supported and electrode-supported types based on their support structure. Electrode-supported PCFCs can be further divided into fuel electrode-supported, air electrode-supported, and metal-supported types. Electrolyte-supported battery types require a thick electrolyte layer to provide mechanical strength, resulting in high ohmic impedance and lower electrochemical performance. In fuel-supported electrode-supported battery types, volume changes in Ni during reduction or long-term operation can negatively impact the battery structure, potentially leading to deactivation. Air-supported battery types, on the other hand, achieve a thin electrolyte while exhibiting good thermal shock resistance and increased fuel applicability. However, air-supported PCFCs face challenges during high-temperature calcination, including increased polarization impedance due to support shrinkage during electrolyte densification and decreased electrolyte conductivity due to the reaction between the air electrode and the electrolyte. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing an air electrode supported proton ceramic fuel cell, which can solve the problem of increased polarization impedance and avoid the problem of decreased electrolyte conductivity caused by the reaction between the air electrode and the electrolyte.

[0004] To achieve the above objectives, the present invention provides a method for preparing an air electrode-supported proton ceramic fuel cell, comprising the following steps: firstly, ball milling to prepare a phase inversion slurry; then, preparing a BZCYYb support with through-holes using a phase inversion casting-spin-coating-impregnation technique; next, preparing an electrolyte layer using a spin-coating method; preparing a NiO-BZCYYb composite fuel electrode using a screen printing-sintering method; and finally, impregnating an air electrode active material to obtain an air electrode-supported proton ceramic fuel cell with a nanostructure and a regular and interconnected through-hole structure.

[0005] As a further aspect of the present invention, it specifically includes the following steps:

[0006] Step S1: Prepare the solvent required for phase inversion, and ball mill at 380 rpm for 12 h to obtain solution 1;

[0007] Step S2: Mix commercial BZCYYb powder with solution 1 from step S1 at the mass ratio, and ball mill for 12 hours to obtain phase inversion BZCYYb casting slurry;

[0008] Step S4: Vacuum treat the BZCYYb casting slurry for 30 min to remove air bubbles, cast the BZCYYb casting slurry onto a glass plate with a casting blade height of 1200 μm, and then immediately place the glass plate into a water tank to carry out the phase transformation process. Transform in water for 10 h to obtain the BZCYYb through-hole preform.

[0009] Step S5: Cut the converted preform into round slices with a diameter of 15mm, dry them in an oven at 80-100℃, and then heat them at 1000℃ for 2 hours in a high-temperature sintering furnace to remove the glue.

[0010] Step S6: Prepare the electrolyte solution required for spin coating, and mix the electrolyte solution with BZCYYb to prepare the BZCYYb electrolyte solution;

[0011] Step S7: Use a spin coater to evenly coat the BZCYYb electrolyte solution onto one side of the dry embryo skin layer. After drying in an oven, sinter at high temperature to make the electrolyte dense. Screen print the fuel electrode slurry and sinter to obtain a BZCYYb-supported half cell with through holes.

[0012] Step S8: Prepare the required impregnation solution, and impregnate the above sintered battery frame with the impregnation solution in small amounts and multiple times. Each impregnation requires calcination.

[0013] Step S9: Sinter the impregnated battery at high temperature to obtain a full cell.

[0014] As a further aspect of the present invention, the preparation method of solution 1 is as follows: polyethersulfone, polyvinylpyrrolidone K-30 and N-methyl-2-pyrrolidone are added to a ball mill jar in a mass ratio of 3.5:0.35:20. Zirconium beads of appropriate size and weight are added to the ball mill jar, and planetary ball milling is performed for 12 hours to obtain a transparent and clear solution 1.

[0015] As a further aspect of the present invention, the preparation of the phase inversion BZCYYb casting slurry specifically includes: adding BZCYYb powder, graphite and solution 1 into a ball mill jar at a mass ratio of 1:0.1:0.45, adding zirconium beads at a mass ratio of 1:1 to the powder into the ball mill jar, and ball milling in a planetary ball mill for 12 hours to obtain the phase inversion BZCYYb casting slurry.

[0016] As a further aspect of the present invention: Preparation of the electrolyte solution in step S6: BZCYYb, organic solvent, dispersant and binder are placed in a ball mill jar, zirconium beads of appropriate size and weight are added to the ball mill jar, and planetary ball milling is performed for 24 hours to obtain a uniformly mixed BZCYYb electrolyte solution; the disc obtained in step S5 is spin-coated with the BZCYYb electrolyte solution on the skin layer side of the blank using a spin coater to obtain a thin film electrolyte layer, which is dried in an oven at 50°C for 30 minutes and then sintered at 1450°C for 6 hours to make the electrolyte dense;

[0017] The binder, BZCYYb powder, and NiO powder were ground and mixed in a mortar. The mass ratio of NiO powder to BZCYYb powder was 6:4, and the mass ratio of the two mixed powders to the binder was 1:1. After grinding for 1 hour, a screen printing paste for the fuel electrode was obtained. The obtained paste was screen printed on the surface of the dense BZCYYb electrolyte of the half cell, dried at 80°C, and sintered at 1100°C for 3 hours.

[0018] As a further aspect of the present invention: In step S8, the impregnation solution is prepared as follows: To prepare a 0.1 mol / L impregnation solution, firstly, Pr(NO3)36H2O, Ba(NO3)2, Sr(NO3)2, Co(NO3)36H2O, and Fe(NO3)39H2O in stoichiometric proportions are dissolved in an appropriate amount of deionized water. Then, 5% polyvinylpyrrolidone K-30 (based on the total mass of nitrates) is added. Finally, glycine is added, wherein the molar ratio of glycine to nitrate in the impregnation solution is 1:1. The mixture is stirred continuously until completely dissolved. The chemical formula of the impregnation solution is PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF).

[0019] As a further aspect of the present invention: In step S9, 10 μL of impregnation liquid is added to the through hole using a pipette. Each impregnation is calcined at 400°C for 1 hour, and the weight is weighed until the impregnation amount is 10% of the mass of the battery frame. Then, it is sintered at 850°C for 2 hours to obtain an air-supported proton ceramic fuel cell with a nanostructure and a regular and interconnected through hole structure.

[0020] As a further aspect of the present invention: BZCYYb is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ .

[0021] Compared with existing technologies, this invention utilizes a phase transformation casting-spin-coating-impregnation technique to fabricate a through-hole structure air-supported proton ceramic fuel cell with loaded nanoelectrodes. BaZr with a through-hole structure is fabricated using the phase transformation casting technique. 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ The (BZCYYb) support, with its through-hole structure, exhibits low tortuosity, reducing diffusion resistance of gases on the air side. Spin-coating technology allows for the preparation of thin electrolyte layers, thereby reducing the ohmic impedance of the battery and improving its electrochemical performance. Furthermore, the through-hole structure is impregnated with PrBa, a substrate known for its excellent catalytic activity. 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF) air electrode material avoids the reaction between the electrode material and the electrolyte during the high-temperature sintering and densification process of the electrolyte. Furthermore, the impregnation technology of nanoparticles greatly increases the number of three-phase reaction sites, thereby improving the electrocatalytic activity of the air electrode. Attached Figure Description

[0022] Figure 1 This is a SEM image of the BZCYYb skeleton of the through hole of the present invention.

[0023] Figure 2 This is a full-cell performance diagram of the present invention. Detailed Implementation

[0024] The invention will now be further described with reference to the accompanying drawings.

[0025] A method for preparing an air electrode-supported proton ceramic fuel cell includes the following steps: first, ball milling to prepare a phase inversion slurry; then, preparing a BZCYYb support with through-pores using a phase inversion casting-spin-coating-impregnation technique; next, preparing an electrolyte layer using a spin-coating method; preparing a NiO-BZCYYb composite fuel electrode using a screen printing-sintering method; and finally, impregnating an air electrode active material to obtain an air electrode-supported proton ceramic fuel cell with a nanostructure and a regular and interconnected through-pore structure.

[0026] The specific steps are as follows:

[0027] Step S1: Prepare the solvent required for phase inversion, and ball mill at 380 rpm for 12 h to obtain solution 1.

[0028] Step S2: Mix commercial BZCYYb powder with solution 1 from step S1 at the mass ratio, and ball mill for 12 hours to obtain phase inversion BZCYYb casting slurry.

[0029] Step S4: Vacuum treat the BZCYYb casting slurry for 30 min to remove air bubbles, cast the BZCYYb casting slurry onto a glass plate with a casting blade height of 1200 μm, and then immediately place the glass plate into a water tank to carry out the phase transformation process. Transform in water for 10 h to obtain the BZCYYb through-hole preform.

[0030] Step S5: Cut the converted preform into round slices with a diameter of 15mm, dry them in an oven at 80-100℃, and then heat them at 1000℃ for 2 hours in a high-temperature sintering furnace to remove the glue.

[0031] Step S6: Prepare the electrolyte solution required for spin coating, and mix the electrolyte solution with BZCYYb to prepare the BZCYYb electrolyte solution;

[0032] Step S7: Use a spin coater to evenly coat the BZCYYb electrolyte solution onto one side of the dry embryo skin layer. After drying in an oven, sinter at high temperature to make the electrolyte dense. Screen print the fuel electrode slurry and sinter to obtain a BZCYYb-supported half cell with through holes.

[0033] Step S8: Prepare the required impregnation solution, and impregnate the above sintered battery frame with the impregnation solution in small amounts and multiple times. Each impregnation requires calcination.

[0034] Step S9: Sinter the impregnated battery at high temperature to obtain a full cell.

[0035] Preparation of Solution 1: Polyethersulfone (PESF, binder, 10-15%), polyvinylpyrrolidone K-30 (PVP, dispersant, 1-2%) and N-methyl-2-pyrrolidone (NMP, solvent) were added to a ball mill jar at a mass ratio of 3.5:0.35:20. Zirconium beads of appropriate size and weight were added to the ball mill jar, and the mixture was ball milled for 12 hours to obtain a transparent and clear solution 1.

[0036] Preparation of phase inversion BZCYYb casting slurry: BZCYYb powder, graphite and solution 1 were added to a ball mill jar at a mass ratio of 1:0.1:0.45. Zirconium beads with a mass ratio of 1:1 to the powder were added to the ball mill jar. The mixture was ball milled in a planetary ball mill for 12 hours to obtain phase inversion BZCYYb casting slurry.

[0037] The phase-inversion BZCYYb casting slurry was vacuum-treated for 30 minutes to remove air bubbles. The BZCYYb casting slurry was then cast onto a glass plate using a casting knife with a height of 1200 μm. The glass plate was then immediately placed in a water tank to carry out the phase inversion process. The phase inversion was carried out in water for 10 hours to obtain a BZCYYb preform with through holes.

[0038] Cut the BZCYYb through hole blank obtained in the above steps into a circular piece with a diameter of 15mm. Place the cut circular piece in an oven at 80-100℃ to dry, and keep it at 1000℃ for 2 hours to remove the glue.

[0039] The regular and interconnected through-hole support structure prepared by phase transformation casting technology ensures excellent gas transport and also facilitates the uniform dispersion of active nanoparticles during the subsequent impregnation process.

[0040] Preparation of BZCYYb electrolyte solution: BZCYYb, organic solvent, dispersant, and binder were placed in a ball mill jar. Zirconium beads of appropriate size and weight were added to the jar, and the mixture was ball milled for 24 hours to obtain a uniformly mixed BZCYYb electrolyte solution. The raw wafer was spin-coated with the BZCYYb electrolyte solution onto the skin layer side using a spin coater to obtain a thin electrolyte layer. After drying in a 50°C oven for 30 minutes, the layer was sintered at 1450°C for 6 hours to densify the electrolyte. The spin-coating method ensured the acquisition of a thin and dense electrolyte layer. Furthermore, since both the support and the electrolyte layer were made of BZCYYb, the sintering shrinkage during high-temperature sintering was more uniform, further ensuring the density of the electrolyte layer.

[0041] Preparation of the fuel electrode: The binder, BZCYYb powder and NiO powder were ground and mixed in a mortar. The mass ratio of NiO powder to BZCYYb powder was 6:4, and the mass ratio of the two mixed powders to the binder was 1:1. After grinding for 1 hour, a screen printing paste for the fuel electrode was obtained. The obtained paste was screen printed on the surface of the dense BZCYYb electrolyte of the half cell, dried at 80°C, and sintered at 1100°C for 3 hours.

[0042] PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ Preparation of (PBSCF) impregnation solution: To prepare a 0.1 mol / L impregnation solution, first dissolve Pr(NO3)36H2O, Ba(NO3)2, Sr(NO3)2, Co(NO3)36H2O, and Fe(NO3)39H2O in an appropriate amount of deionized water in stoichiometric proportions. Then add 5% polyvinylpyrrolidone K-30 (total mass of nitrates). Finally, add glycine, with the molar ratio of glycine to nitrate in the impregnation solution being 1:1. Stir continuously until completely dissolved.

[0043] Full cell fabrication: 10 μL of impregnation solution was pipetted into the through-holes. Each impregnation was followed by calcination at 400 °C for 1 h, and the mixture was weighed until the impregnation volume reached 10% of the battery frame mass. The cells were then sintered at 850 °C for 2 h to obtain an air-electrode supported proton ceramic fuel cell with a nanostructure and a regular, interconnected through-hole structure. The impregnation solution in the through-holes provides a PBSCF air electrode with high conductivity and high catalytic activity, ensuring electron conduction and catalytic activity while preventing reactions between the electrolyte and the air electrode caused by high-temperature sintering.

[0044] BZCYYb is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ .

[0045] The through-hole BZCYYb support obtained by phase transformation casting ensures excellent gas transmission, while the regular and continuous through-holes are more conducive to the uniform distribution of impregnated active materials.

[0046] A major challenge in proton ceramic fuel cells is obtaining a dense electrolyte layer with high conductivity. In this preparation method, the support and electrolyte are made of the same material, and they shrink uniformly during high-temperature sintering, which is more conducive to the dense sintering of the electrolyte. Compared with traditional proton ceramic cells supported by the fuel electrode, this method can effectively alleviate the problem of battery performance degradation caused by the migration of Ni from the fuel electrode to the electrolyte at high temperatures. Compared with air-supported proton ceramic fuel cells prepared by traditional co-sintering, this method can avoid the problem of battery performance degradation caused by the reaction between the electrolyte and air electrode materials during high-temperature calcination to generate other impurity phases.

[0047] The support is a through-hole structure that facilitates gas diffusion and impregnation of active materials, electrolyte, and air. It contains nanoparticles with high conductivity and high catalytic activity, thus providing good testing performance and promising application prospects.

[0048] The air-supported proton ceramic fuel cell obtained by the method of this invention was subjected to SEM scanning and electrochemical performance testing, and the results are as follows: Figure 1 The image shown is a SEM image of the BZCYYb framework with through-holes. It reveals that the phase transformation casting channels are interconnected and continuous, which is beneficial for gas transport and the dispersion of active nanoparticles during impregnation. Figure 2 The graph shows the full cell performance, which is 410.8 mW / cm² at 700℃. -2 .

Claims

1. A method for preparing an air electrode-supported proton ceramic fuel cell, characterized in that, Includes the following steps: First, a phase inversion slurry is prepared by ball milling. Then, a BZCYYb support with through holes is prepared by phase inversion casting-spin coating-impregnation technology. Next, an electrolyte layer is prepared by spin coating. A NiO-BZCYYb composite fuel electrode is prepared by screen printing-sintering. Finally, an air electrode active material is impregnated to obtain an air electrode supported proton ceramic fuel cell with a nanostructure and a regular and interconnected through hole structure. Specifically, the following steps are included: Step S1: Prepare the solvent required for phase inversion, and ball mill at 380 rpm for 12 h to obtain solution 1; Step S2: Mix commercial BZCYYb powder with solution 1 from step S1 at the mass ratio, and ball mill for 12 hours to obtain phase inversion BZCYYb casting slurry; Step S3: Vacuum treat the BZCYYb casting slurry for 30 minutes to remove air bubbles, and cast the BZCYYb casting slurry onto a glass plate using a casting knife with a height of 1200μm. Immediately afterwards, place the glass plate into a water tank to carry out the phase transformation process. Transform in water for 10 hours to obtain a BZCYYb preform with through holes. Step S4: Cut the transformed embryo into round slices with a diameter of 15mm and place them at 80-100°C. o Dry in oven C, and then heat at 1000℃ for 2 hours in a high-temperature sintering furnace to remove the adhesive; Step S5: Prepare the electrolyte solution required for spin coating. Place BZCYYb, organic solvent, dispersant and binder into a ball mill jar. Add zirconium beads of appropriate size and weight to the ball mill jar and ball mill for 24 hours to obtain a uniformly mixed BZCYYb electrolyte solution. Step S6: Use a spin coater to evenly coat the BZCYYb electrolyte solution onto one side of the dry embryo skin layer. After drying in an oven, sinter at high temperature to make the electrolyte dense. Screen print the fuel electrode slurry and sinter to obtain a BZCYYb-supported half cell with through holes. Step S7: Prepare the required impregnation solution, and impregnate the above sintered battery frame with the impregnation solution in small amounts and multiple times. Each impregnation requires calcination. Step S8: Sinter the impregnated battery at high temperature to obtain a full cell.

2. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, The preparation method of solution 1 is as follows: polyethersulfone, polyvinylpyrrolidone K-30 and N-methyl-2-pyrrolidone are added to a ball mill jar in a mass ratio of 3.5:0.35:

20. Zirconium beads of appropriate size and weight are added to the ball mill jar, and the mixture is ball milled for 12 hours to obtain a transparent and clear solution 1.

3. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, The specific preparation of the phase inversion BZCYYb casting slurry includes: adding BZCYYb powder, graphite and solution 1 into a ball mill jar at a mass ratio of 1:0.1:0.45, adding zirconium beads at a mass ratio of 1:1 to the powder into the ball mill jar, and ball milling in a planetary ball mill for 12 hours to obtain the phase inversion BZCYYb casting slurry.

4. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, Preparation of electrolyte solution in step S5: BZCYYb, organic solvent, dispersant and binder are placed in a ball mill jar, and zirconium beads of appropriate size and weight are added to the ball mill jar. The mixture is ball milled for 24 hours to obtain a uniformly mixed BZCYYb electrolyte solution. The disc obtained in step S4 is spin-coated with the BZCYYb electrolyte solution on the skin layer side of the blank using a spin coater to obtain a thin electrolyte layer. After drying in an oven at 50°C for 30 minutes, the electrolyte layer is sintered at 1450°C for 6 hours to make the electrolyte dense. The binder, BZCYYb powder, and NiO powder were ground and mixed in a mortar. The mass ratio of NiO powder to BZCYYb powder was 6:4, and the mass ratio of the two mixed powders to the binder was 1:

1. After grinding for 1 hour, a screen printing paste for the fuel electrode was obtained. The obtained paste was screen printed on the surface of the dense BZCYYb electrolyte of the half cell, dried at 80°C, and sintered at 1100°C for 3 hours.

5. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, In step S7, the impregnation solution is prepared as follows: To prepare a 0.1 mol / L impregnation solution, first dissolve Pr(NO3)36H2O, Ba(NO3)2, Sr(NO3)2, Co(NO3)36H2O, and Fe(NO3)39H2O in an appropriate amount of deionized water in stoichiometric proportions. Then add 5% polyvinylpyrrolidone K-30 (based on the total mass of nitrates). Finally, add glycine, where the molar ratio of glycine to nitrate in the impregnation solution is 1:

1. Stir continuously until completely dissolved. The chemical formula of the impregnation solution is PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ (PBSCF).

6. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, In step S8, 10 µL of impregnation liquid is added to the through hole using a pipette. Each impregnation is calcined at 400°C for 1 hour. The liquid is weighed until the impregnation amount is 10% of the battery frame mass. Then, it is sintered at 850°C for 2 hours to obtain an air-supported proton ceramic fuel cell with a nanostructure and a regular and interconnected through hole structure.

7. The method for preparing an air electrode-supported proton ceramic fuel cell according to claim 1, characterized in that, BZCYYb is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ 。

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