A method for fabricating a planar anode-supported solid oxide fuel cell and the solid oxide fuel cell

Abstract

This invention relates to a method for fabricating a planar anode-supported solid oxide fuel cell and the solid oxide fuel cell itself. The fabrication method includes the following steps: preparation of a support slurry and anode support green body; preparation of functional layer slurry and functional layer; preparation of electrolyte layer slurry and electrolyte layer; debinding and sintering; preparation of barrier layer slurry and barrier layer; preparation of cathode layer slurry and cathode layer; and molding and sintering. The solid oxide fuel cell includes an anode support, an anode functional layer, an electrolyte layer, a barrier layer, and a cathode layer. This invention features a short process flow, low production cost, multiple active sites in the battery reaction, and good battery performance.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a method for preparing a planar anode-supported solid oxide fuel cell and the solid oxide fuel cell itself. Background Technology

[0002] As a novel power generation technology, fuel cells offer numerous advantages, including high efficiency, cleanliness, and safety. Solid oxide fuel cells (SOFCs), in addition to sharing the common advantages of fuel cells such as high efficiency and environmental friendliness, offer greater design flexibility, easier operation, and enhanced safety and reliability due to their all-solid-state nature.

[0003] Planar anode-supported solid oxide fuel cells are a type of solid oxide fuel cell. Currently, the fabrication of planar anode-supported solid oxide fuel cells mainly involves preparing a support green body through tape casting, stacking them together by warm isostatic pressing, then casting an electrolyte slurry to form an electrolyte green body, which is then stacked with the anode support layer and warm isostatically pressed together, followed by sintering to form a half-cell. Finally, a barrier layer is printed, sintered, and a cathode is printed and sintered to prepare a full cell, or the cathode is directly printed and sintered to prepare a full cell.

[0004] However, batteries prepared in this way suffer from high production costs, complex processes, and inconsistent casting formulations for the support and electrolyte. Poor bonding between the two under isostatic pressing conditions can lead to impurities and delamination, all of which negatively impact battery performance. Furthermore, the electrolyte layer requires a thin layer, which is difficult to control; uneven or excessive thickness can affect battery performance. Additionally, the absence of an anode functional layer results in fewer reactive sites, naturally leading to lower performance. Moreover, in existing technologies, the barrier layer and cathode layer must be sintered separately due to different sintering temperatures, resulting in numerous sintering cycles and a lengthy process. Summary of the Invention

[0005] To overcome the problems existing in the prior art, this invention provides a method for preparing a planar anode-supported solid oxide fuel cell and a solid oxide fuel cell, which has the characteristics of short process flow, low production cost, multiple active sites for battery reaction and good battery performance.

[0006] The technical solution adopted in this invention is:

[0007] A method for fabricating a planar anode-supported solid oxide fuel cell includes the following steps:

[0008] Step S1: Using nickel oxide powder, 3YSZ powder and 8YSZ powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, ball mill to prepare support slurry, and then use casting molding to obtain a thin blank with a thickness of 150μm.

[0009] Three thin blanks are aligned and stacked using a stacking machine to form a stacked blank. The stacked blank is then subjected to warm isostatic pressing and cutting to obtain the anode support green blank.

[0010] Step S2: Using 8YSZ powder and nickel oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to degas, ball mill to prepare functional layer slurry;

[0011] The functional layer paste is uniformly deposited onto the anode support preform by screen printing and dried at 40-60℃ for 1-4 hours to form the anode functional layer.

[0012] Step S3: Using 8YSZ powder as the main raw material, mix it with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare electrolyte layer slurry;

[0013] The electrolyte layer slurry is uniformly deposited onto the anode functional layer using screen printing, and then dried at 40-60℃ for 1-4 hours to form the electrolyte layer.

[0014] Step S4: The anode support green body with electrolyte layer and anode functional layer is debonded and sintered to obtain a half cell;

[0015] Step S5: Using GDC powder as the main raw material, mix it with iron oxide or cobalt oxide, solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare barrier layer slurry;

[0016] The barrier layer slurry is uniformly deposited onto the half-cell using screen printing and dried at 40-60℃ for 1-4 hours to form the barrier layer.

[0017] Step S6: Using LSCF powder and cerium oxide-doped zirconium oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare cathode layer slurry;

[0018] The LSCF layer slurry is uniformly deposited onto the barrier layer using screen printing and dried at 40~60℃ for 1~4h to form the cathode layer.

[0019] Step S7: The half-cell with the barrier layer and the cathode layer is shaped and sintered to obtain a planar anode-supported solid oxide fuel cell.

[0020] Further, in step S1, the weight ratio of nickel oxide powder, 3YSZ powder and 8YSZ powder is 11:8:1;

[0021] And / or, in step S2, the weight ratio of 8YSZ powder to nickel oxide powder is 2:3;

[0022] And / or, in step S6, the weight ratio of LSCF powder to cerium oxide-doped zirconium oxide powder is 1.78:1.

[0023] Furthermore, in steps S1 to S3, as well as steps S5 and S6, the solvent is one or more of ethanol, butanone, and diethylene glycol monobutyl ether.

[0024] The adhesive is one or more of polyvinyl butyral and ethyl cellulose;

[0025] The plasticizer is one or more of dibutyl phthalate, polyethylene glycol, and bis(2-ethylhexyl) adipate;

[0026] The dispersant is one or more of the following: stearic acid, fish oil, Span 83, dispersant KMT-3004, and dispersant BYK-110.

[0027] Further, in step S1, the mixture of nickel oxide powder, 3YSZ powder and 8YSZ powder comprises 54% by weight percentage (total weight percentage is 100%), solvent comprises 36%, binder comprises 5%, plasticizer comprises 4%, and dispersant comprises 1%.

[0028] And / or, in step S2, the mixture of 8YSZ powder and nickel oxide powder comprises 63% by weight, 32% by volume, 2% by volume, 2% by volume, and 1% by volume.

[0029] And / or, in step S3, the total mass percentage is 70% 8YSZ powder, 24% solvent, 3% binder, 2% plasticizer, and 1% dispersant;

[0030] And / or, in step S5, based on a total mass percentage of 100%, the composition is: 58.5% GDC powder, 1.5% iron oxide or cobalt oxide, 35% solvent, 2% binder, 2% plasticizer, and 1% dispersant;

[0031] And / or, in step S6, the mixture of LSCF powder and cerium oxide-doped zirconium oxide powder is 71.6% by mass percentage, the solvent is 20%, the binder is 7%, the plasticizer is 1.2%, and the dispersant is 0.2%.

[0032] Furthermore, in step S5, the iron oxide is FeO, Fe2O3, or Fe3O4; the cobalt oxide is CoO or Co2O3.

[0033] Furthermore, in step S2, the screen printing of the anode functional layer is performed once or multiple times;

[0034] In step S3, the electrolyte layer is screen printed once or multiple times.

[0035] In step S5, the barrier layer is screen printed once or multiple times.

[0036] In step S6, the cathode layer screen printing is performed once or multiple times.

[0037] Furthermore, in step S4, the specific process of debinding and sintering is as follows: from room temperature at 2~5℃ / min to 450℃ and hold for 2 hours, then naturally cool to room temperature; then from room temperature at 2~5℃ / min to 1400℃ and hold for 2 hours, then cool down to 450℃ at 2~5℃ / min, and naturally cool to room temperature.

[0038] Furthermore, in step S4, during the debinding sintering, a zirconia plate is used as the firing plate, a porous alumina ceramic plate is used as the cover plate, and an anode support green body with an electrolyte layer and an anode functional layer is placed between the firing plate and the cover plate.

[0039] Furthermore, in step S7, when the half-cell with the barrier layer and the cathode layer is shaped and sintered, the temperature is 1050~1100℃ and the time is 2~3h.

[0040] Based on the same inventive concept, the present invention also provides a planar anode-supported solid oxide fuel cell, which is prepared by the aforementioned method for preparing a planar anode-supported solid oxide fuel cell. From bottom to top, the planar anode-supported solid oxide fuel cell sequentially includes an anode support, an anode functional layer, an electrolyte layer, a barrier layer, and a cathode layer. The thickness of the anode support is 380-400 μm; the thickness of the anode functional layer is 10-20 μm; the thickness of the electrolyte layer is 9-12 μm; the thickness of the barrier layer is 2-5 μm; and the thickness of the cathode layer is 20-30 μm.

[0041] The beneficial effects of this invention are:

[0042] 1. This invention provides a method for fabricating a planar anode-supported solid oxide fuel cell. The method combines casting, screen printing, debinding sintering, and molding sintering processes, reducing the number of sintering steps compared to existing technologies, resulting in a simpler process, lower cost, and higher yield. Furthermore, this invention first uses casting to obtain a 150μm thick blank, which is then stacked in three layers and isostatically pressed. Compared to casting to a specified thickness or more stacked layers in a single step, this invention offers advantages in terms of thickness error and yield of the anode support blank. Moreover, the similarity in composition between the anode support, anode functional layer, and electrolyte layer in this invention helps improve the bonding strength between layers and ensures battery performance. Additionally, the use of screen printing to fabricate the electrolyte layer significantly improves the uniformity of electrolyte layer thickness, further enhancing battery performance. Finally, this invention introduces iron oxide or cobalt oxide into the barrier layer composition, lowering the sintering temperature and achieving co-firing of the barrier layer and cathode layer at 1050~1100℃, reducing the number of sintering steps without affecting the cathode layer.

[0043] 2. This invention provides a planar anode-supported solid oxide fuel cell, which increases the number of reactive sites and improves battery performance by adding an anode functional layer. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the fabrication process of a planar anode-supported solid oxide fuel cell.

[0045] Figure 2 The appearance of a half-cell made when the support slurry composition does not contain 8YSZ.

[0046] Figure 3 The appearance of the half-cell prepared in Example 1.

[0047] Figure 4 This is a cross-sectional SEM image of the half-cell (three-layer structure) prepared in Example 1.

[0048] Figure 5 This is a cross-sectional SEM image of a half-cell (two-layer structure).

[0049] Figure 6 This is a cross-sectional SEM image of the planar anode-supported solid oxide fuel cell fabricated in Example 1. Detailed Implementation

[0050] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0051] A method for fabricating a planar anode-supported solid oxide fuel cell, the process of which is shown in the attached figure. Figure 1As shown in the figure. The preparation method includes the following steps:

[0052] Step S1: Using nickel oxide powder, 3YSZ powder and 8YSZ powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, ball mill to prepare support slurry, and then use casting molding to obtain a thin blank with a thickness of 150μm.

[0053] Three thin blanks are aligned and stacked using a laminating machine to form a laminated blank. The laminated blank is then subjected to warm isostatic pressing and trimming to obtain the anode support green blank.

[0054] Step S2: Using 8YSZ powder and nickel oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to degas, ball mill to prepare functional layer slurry;

[0055] The functional layer paste is uniformly deposited onto the anode support preform by screen printing and dried at 40-60℃ for 1-4 hours to form the anode functional layer.

[0056] Step S3: Using 8YSZ powder as the main raw material, mix it with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare electrolyte layer slurry;

[0057] The electrolyte layer slurry is uniformly deposited onto the anode functional layer using screen printing, and then dried at 40-60℃ for 1-4 hours to form the electrolyte layer.

[0058] Step S4: The anode support green body with electrolyte layer and anode functional layer is debonded and sintered to obtain a half cell;

[0059] Step S5: Using GDC powder as the main raw material, mix it with iron oxide or cobalt oxide, solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare barrier layer slurry;

[0060] The barrier layer slurry is uniformly deposited onto the half-cell using screen printing and dried at 40-60℃ for 1-4 hours to form the barrier layer.

[0061] Step S6: Using LSCF powder and cerium oxide-doped zirconium oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare cathode layer slurry;

[0062] The LSCF layer slurry is uniformly deposited onto the barrier layer using screen printing and dried at 40~60℃ for 1~4h to form the cathode layer.

[0063] Step S7 involves sintering the half-cell with a barrier layer and a cathode layer to obtain a method for preparing a planar anode-supported solid oxide fuel cell.

[0064] The planar anode-supported solid oxide fuel cell prepared by the aforementioned method comprises, from bottom to top, an anode support, an anode functional layer, an electrolyte layer, a barrier layer, and a cathode layer; wherein, the thickness of the anode support is 380-400 μm; the thickness of the anode functional layer is 10-20 μm; the thickness of the electrolyte layer is 9-12 μm; the thickness of the barrier layer is 2-5 μm; and the thickness of the cathode layer is 20-30 μm.

[0065] In this embodiment, a combination of casting, screen printing, debinding sintering, and molding sintering is used, which reduces the number of sintering steps compared to existing technologies, resulting in a simpler process, lower cost, and higher yield. Furthermore, the casting process used in this invention yields a 150μm thick blank, which is then stacked in three layers and isostatically pressed. Compared to casting to a specified thickness or a higher number of stacked layers in a single step, this invention offers advantages in terms of anode support thickness error and support yield. Moreover, the anode support, anode functional layer, and electrolyte layer in this invention share certain similarities in composition, which helps improve the bonding strength between layers and ensures battery performance. Finally, the electrolyte layer is fabricated using screen printing, which significantly improves the uniformity of electrolyte layer thickness, further contributing to battery performance.

[0066] It should be noted that in this embodiment, "main raw material" refers to the component whose weight percentage is the highest in the overall composition.

[0067] Further, in step S1, the weight ratio of nickel oxide powder, 3YSZ powder, and 8YSZ powder is 11:8:1. In step S2, the weight ratio of 8YSZ powder to nickel oxide powder is 2:3. In step S6, the weight ratio of LSCF powder to cerium oxide-doped zirconium oxide powder is 1.78:1.

[0068] Further, in steps S1 to S3, as well as steps S5 and S6, the solvent is one or more of ethanol, methyl ethyl ketone (MEK), and diethylene glycol monobutyl ether. The adhesive is one or more of polyvinyl butyral (PVB) and ethyl cellulose. The plasticizer is one or more of dibutyl phthalate (DBP), polyethylene glycol (PEG), and bis(2-ethylhexyl) adipate. The dispersant is one or more of stearic acid, fish oil, Span 83, dispersant KMT-3004, and dispersant BYK-110.

[0069] Further, in step S1, based on a total mass percentage of 100%, the mixture of nickel oxide powder, 3YSZ powder, and 8YSZ powder comprises 54%, solvent 36%, binder 5%, plasticizer 4%, and dispersant 1%. In step S2, based on a total mass percentage of 100%, the mixture of 8YSZ powder and nickel oxide powder comprises 63%, solvent 32%, binder 2%, plasticizer 2%, and dispersant 1%. In step S3, based on a total mass percentage of 100%, 8YSZ powder comprises 70%, solvent 24%, binder 3%, plasticizer 2%, and dispersant 1%. In step S5, based on a total mass percentage of 100%, GDC powder comprises 58.5%, iron oxide or cobalt oxide 1.5%, solvent 35%, binder 2%, plasticizer 2%, and dispersant 1%. In step S6, the mixture of LSCF powder and cerium oxide-doped zirconium oxide powder comprises 71.6% by mass percentage, 20% by solvent, 7% by binder, 1.2% by plasticizer, and 0.2% by dispersant.

[0070] Furthermore, in step S5, the iron oxide is FeO, Fe2O3, or Fe3O4; the cobalt oxide is CoO or Co2O3.

[0071] Further, in step S2, the screen printing of the anode functional layer is performed once or multiple times. In step S3, the screen printing of the electrolyte layer is performed once or multiple times. In step S5, the screen printing of the barrier layer is performed once or multiple times. In step S6, the screen printing of the cathode layer is performed once or multiple times.

[0072] It should be noted that when using multiple screen printing processes, each previous screen printing process needs to be dried at 40~60℃ for 1~4 hours to ensure the reliability of adhesion between the printed layers.

[0073] Furthermore, in step S4, the specific process of debinding and sintering is as follows: from room temperature at 2~5℃ / min to 450℃ and hold for 2 hours, then naturally cool to room temperature; then from room temperature at 2~5℃ / min to 1400℃ and hold for 2 hours, then cool down to 450℃ at 2~5℃ / min, and naturally cool to room temperature.

[0074] Furthermore, in step S4, during the debinding sintering, a zirconia plate is used as the firing plate, a porous alumina ceramic plate is used as the cover plate, and an anode support green body with an electrolyte layer and an anode functional layer is placed between the firing plate and the cover plate.

[0075] Furthermore, in step S7, when the half-cell with the barrier layer and the cathode layer is sintered, the temperature is 1050~1100℃ and the time is 2~3h.

[0076] The following will illustrate this with more specific examples.

[0077] Example 1

[0078] Fabrication method of planar anode-supported solid oxide fuel cell:

[0079] (1) Preparation of support slurry and anode support green body.

[0080] The nickel oxide powder, 3YSZ powder (3 mol yttrium-stabilized zirconium oxide), and 8YSZ powder (8 mol yttrium-stabilized zirconium oxide) were mixed in a weight ratio of 11:8:1, with a total weight percentage of 54 wt%. Ethanol and butanone were mixed in a weight ratio of 3:2, with a total weight percentage of 36 wt%. The nickel oxide powder, 3YSZ powder, 8YSZ, ethanol, butanone, and 1 wt% fish oil were then mixed and ball-milled at 250 rpm for 4–8 hours. Then, 4 wt% DBP and 5 wt% PVB were added, and the mixture was ball-milled at 200 rpm for 4–6 hours.

[0081] The above-mentioned support slurry is cast into a thin blank with a thickness of 150μm using a casting machine. After being laminated into three layers by a laminating machine, a laminated blank with a thickness of 450μm is obtained. The blank is then subjected to warm isostatic pressing and cut to the specified size to obtain the anode support green blank.

[0082] (2) Preparation of functional layer slurry and anode functional layer

[0083] The slurry was prepared by mixing 8YSZ powder and nickel oxide powder in a weight ratio of 2:3, with a total weight percentage of 63 wt%. Diethylene glycol monobutyl ether (DGE) and ethanol were mixed in a weight ratio of 55:45, with a total weight percentage of 32 wt%. 2 wt% PVB was dissolved in a mixture of DGE and ethanol under heating and stirring. Then, 8YSZ powder and nickel oxide powder were added, followed by 2 wt% DBP and 1 wt% Span 83. The mixture was then centrifuged at 800 rpm, 1600 rpm, and 800 rpm for 15 seconds, 60 seconds, and 15 seconds respectively. The mixture was then passed through a three-roll mill 3-4 times in a sequence of 20 μm-10 μm-5 μm-3 μm. The particle size was measured to be below 5 μm using a scraper fineness meter, and the viscosity was measured to be within the set target using a rheometer. The mixture was then vacuum degassed using a low-speed centrifugal mixer before use.

[0084] The functional layer slurry was uniformly deposited onto the anode support preform using screen printing, and then dried at 50°C for 3 hours to form the anode functional layer. The screen printing process was performed three times.

[0085] (3) Preparation of electrolyte layer slurry and electrolyte layer

[0086] Dissolve 3 wt% PVB in 24 wt% diethylene glycol monobutyl ether by heating and stirring, then add 70 wt% 8YSZ powder, and finally add 2 wt% PEG and 1 wt% dispersant BYK-110. Mix the slurry at 800 rpm, 1600 rpm, and 800 rpm for 15 seconds, 60 seconds, and 15 seconds respectively. Then, pass the slurry through a three-roll mill in the order of 20 μm-10 μm-5 μm-3 μm 3-4 times. Test the slurry particle size with a scraper fineness meter; it should be below 5 μm. Test the slurry viscosity with a rheometer; if it meets the set target, then vacuum degas it using a low-speed mixing and degassing machine before use.

[0087] The electrolyte layer slurry was uniformly deposited onto the anode functional layer using screen printing, and then dried at 50°C for 3 hours to form the electrolyte layer. The screen printing process was performed three times.

[0088] (4) Debinding and sintering

[0089] A half-cell is obtained by debinding and sintering an anode support green body with an electrolyte layer and an anode functional layer. The half-cell has a three-layer structure, specifically: an anode support, an anode functional layer, and an electrolyte layer.

[0090] The specific process of debinding and sintering is as follows: from room temperature to 450℃ at a rate of 2℃ / min, hold for 2 hours, then cool naturally to room temperature to release the internal stress during the debinding process. Then, from room temperature to 1400℃ at a rate of 5℃ / min, hold for 2 hours, then cool down to 450℃ at a rate of 5℃ / min, and then cool naturally to room temperature.

[0091] Meanwhile, during the debinding sintering process, a zirconia plate is used as the firing plate and a porous alumina ceramic plate is used as the cover plate. The green anode support with an electrolyte layer and an anode functional layer is placed between the firing plate and the cover plate to solve the problem of nickel oxide sintering diffusion, so that the strength of the anode support is not lost due to diffusion.

[0092] (5) Barrier layer slurry and barrier layer preparation

[0093] PVB 2 wt% was dissolved in diethylene glycol monobutyl ether 35 wt% by heating and stirring. Then, GDC powder (Gd2O3-doped CeO2) 58.5 wt% and Fe2O3 1.5 wt% were added. Finally, PEG 2 wt% and dispersant BYK-110 1 wt% were added. The mixture was then centrifuged at 800 rpm, 1600 rpm and 800 rpm for 15 s, 60 s and 15 s respectively. The mixture was then passed through a three-roll mill in the order of 20 μm-10 μm-5 μm-3 μm 3-4 times. The particle size of the slurry was tested with a scraper fineness meter and found to be below 5 μm. The viscosity of the slurry was tested with a rheometer and found to meet the set target. The slurry was then vacuum degassed using a low-speed centrifuge for use.

[0094] The barrier layer slurry was uniformly deposited onto the half-cell using screen printing and dried at 50°C for 3 hours to form the barrier layer. The screen printing process was performed once.

[0095] (6) Preparation of cathode layer slurry and cathode layer

[0096] According to LSCF powder ((La 0.6 Sr 0.4 ) 0.99 Co 0.2 Fe 0.8 The mixture of O3 and cerium oxide-doped zirconium oxide powder (10Sc1CeSZ) was prepared in a weight ratio of 1.78:1, with a total weight of 71.6 wt%. 7 wt% PVB was dissolved in 20 wt% diethylene glycol monobutyl ether by heating and stirring. Then, LSCF powder and cerium oxide-doped zirconium oxide powder were added, followed by 1.2 wt% bis(2-ethylhexyl) adipic acid and 0.2 wt% stearic acid. The mixture was then centrifuged at 800 rpm, 1600 rpm, and 800 rpm for 15 s, 60 s, and 15 s respectively. The mixture was then passed through a three-roll mill in a sequence of 20 μm-10 μm-5 μm-3 μm 3-4 times. The particle size was measured using a scraper fineness meter and found to be below 5 μm. The viscosity was measured using a rheometer and found to meet the set target. The mixture was then vacuum degassed using a low-speed centrifuge for use.

[0097] The LSCF layer slurry was uniformly deposited onto the barrier layer using screen printing, and then dried at 50°C for 3 hours to form the cathode layer. The screen printing process was performed three times.

[0098] (7) Molding and sintering

[0099] A method for preparing a planar anode-supported solid oxide fuel cell was obtained by sintering a half-cell with a barrier layer and a cathode layer at 1100℃ for 2.5h.

[0100] On the one hand, if the thickness of the solid oxide fuel cell is set at approximately 450 μm, then the thickness difference of the final formed anode support green body during screen printing must be less than 10 μm. A greater thickness difference in the anode support green body will result in a greater thickness difference between the anode functional layer and the electrolyte layer during screen printing. On the other hand, the thicker the support slurry, the higher the slurry tank needs to be, and the slurry in the tank is used up more quickly, requiring more frequent replenishment. Simultaneously, the greater the variation in the thickness of the slurry tank, the greater the impact of the thickness difference in the support slurry. Furthermore, a thicker support slurry reduces the drying uniformity of the tape, thus necessitating the search for the optimal tape thickness.

[0101] Design and produce a green body of an anode support with a thickness of 450 μm. In this embodiment, the final thickness difference and qualification rate of the green body of the anode support after warm isostatic pressing under different thicknesses of thin blanks and different numbers of stacked layers were compared and tested. The statistical results are shown in Table 1 below. Among them, the thickness difference refers to the difference between the thickness of the green body of the anode support after warm isostatic pressing and the target thickness value. The qualification rate statistics the qualified degree of the green body of the anode support after warm isostatic pressing. The green body of the anode support with uniform thickness and no damage is regarded as qualified.

[0102] Table 1 Final thickness difference and qualification rate of the green body of the anode support

[0103] serial number thin blank thickness Number of stacked layers Thickness difference pass rate 1 90μm 5 <5μm 75% 2 112.5μm 4 <7μm 84% 3 150μm 3 <9μm 95% 4 225μm 2 <15μm 97.6% 5 450μm / <28μm 100%

[0104] From the statistical data in Table 1, when the thickness of the thin blank is 150 μm and the number of stacked layers is 3, the comprehensive evaluation of the thickness difference and qualification rate is more advantageous.

[0105] At the same time, in this embodiment, when 8YSZ is not contained in the composition of the support slurry (the weight ratio of nickel oxide powder and 3YSZ powder is 11:8, and the total weight of the two accounts for 54 wt%, and the rest remains the same), the appearance morphology of the half-cell, etc., is as shown in Figure 2 and Figure 3 . Among them, Figure 3 The appearance morphology of the half-cell prepared in Example 1. Figure 2 is the appearance morphology of the half-cell when 8YSZ is not contained in the composition of the support slurry. It can be clearly seen from the figure that after adding a certain proportion of 8YSZ to the composition of the support slurry, the appearance morphology of the half-cell can be significantly improved, ensuring smooth sintering and no warping.

[0106] The SEM images of the half-cell prepared in Example 1 and the half-cell without a functional layer (without the functional layer slurry and the anode functional layer preparation process, and the rest is the same) are as shown in Figure 4 and Figure 5 . It can be seen from the figure that the thickness of the electrolyte layer of the half-cell (three-layer structure) prepared in Example 1 is 18.02 μm, while the thickness of the electrolyte layer of the half-cell without a functional layer (two-layer structure) is 5.369 μm. It can be seen from the figure that when there is no anode functional layer, the thickness of the electrolyte layer in the microscopic state is smaller than that when there is an anode functional layer. This shows that due to the larger voids in the anode support, in the absence of the barrier of the anode functional layer, the electrolyte layer will penetrate into the anode support during the screen printing process of the electrolyte layer, resulting in a decrease in the thickness of the electrolyte layer. And when the thickness of the electrolyte layer is less than 10 μm, it will seriously affect the battery performance.

[0107] Meanwhile, this embodiment also compared and tested the performance of solid oxide fuel cells with and without an anode functional layer (i.e., omitting the functional layer slurry and anode functional layer preparation steps in Example 1, with the rest remaining the same as in Example 1, numbered 1). Additionally, this embodiment compared and tested the performance of solid oxide fuel cells after co-firing the barrier layer and cathode layer and after sintering the barrier layer and cathode layer separately (when sintering the barrier layer and cathode layer separately, Fe2O3 in the barrier layer composition was replaced with GDC powder, with the rest remaining the same as in Example 1, numbered 3), as shown in Table 2.

[0108] Table 2 Battery Performance

[0109]

[0110] On the one hand, the data in Table 2 shows that the planar anode-supported solid oxide fuel cell fabricated without an anode functional layer was damaged during high-temperature testing. On the other hand, the data in Table 2 shows that the solid oxide fuel cell fabricated by co-firing the barrier layer and cathode layer in this invention has comparable performance to the solid oxide fuel cell fabricated by firing the barrier layer and cathode layer separately, which also demonstrates that the method in this invention can achieve the preparation of a high-performance planar anode-supported solid oxide fuel cell. It also shows that adding Fe2O3 to the barrier layer slurry can lower the sintering temperature of the GDC powder, enabling co-firing of the barrier layer and cathode layer at 1100℃.

[0111] The cross-sectional SEM results of the planar anode-supported solid oxide fuel cell fabricated in Example 1 are as follows: Figure 6 As shown in the figure, the anode support, anode functional layer, electrolyte layer, barrier layer, and cathode layer are firmly bonded together without significant delamination. Furthermore, the figure shows that the electrolyte layer has the lowest porosity among all layers, with porosity gradually increasing from both sides.

Claims

1. A method for fabricating a planar anode-supported solid oxide fuel cell, characterized in that, Includes the following steps: Step S1: Using nickel oxide powder, 3YSZ powder and 8YSZ powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, ball mill to prepare support slurry, and then use casting molding to obtain a thin blank with a thickness of 150μm. Three thin blanks are aligned and stacked using a stacking machine to form a stacked blank. The stacked blank is then subjected to warm isostatic pressing and cutting to obtain the anode support green blank. Step S2: Using 8YSZ powder and nickel oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to degas, ball mill to prepare functional layer slurry; The functional layer paste is uniformly deposited onto the anode support preform by screen printing and dried at 40-60℃ for 1-4 hours to form the anode functional layer. Step S3: Using 8YSZ powder as the main raw material, mix it with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare electrolyte layer slurry; The electrolyte layer slurry is uniformly deposited onto the anode functional layer using screen printing, and then dried at 40-60℃ for 1-4 hours to form the electrolyte layer. Step S4: The anode support green body with electrolyte layer and anode functional layer is debonded and sintered to obtain a half cell; Step S5: Using GDC powder as the main raw material, mix it with iron oxide or cobalt oxide, solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare barrier layer slurry; The barrier layer slurry is uniformly deposited onto the half-cell using screen printing and dried at 40-60℃ for 1-4 hours to form the barrier layer. Step S6: Using LSCF powder and cerium oxide-doped zirconium oxide powder as the main raw materials, mix with solvent, binder, plasticizer and dispersant, centrifuge to remove bubbles, ball mill and prepare cathode layer slurry; The LSCF layer slurry is uniformly deposited onto the barrier layer using screen printing and dried at 40~60℃ for 1~4h to form the cathode layer. Step S7: The half-cell with the barrier layer and the cathode layer is shaped and sintered to obtain a planar anode-supported solid oxide fuel cell.

2. The method for preparing a planar anode-supported solid oxide fuel cell according to claim 1, characterized in that, In step S1, the weight ratio of nickel oxide powder, 3YSZ powder and 8YSZ powder is 11:8:

1. And / or, in step S2, the weight ratio of 8YSZ powder to nickel oxide powder is 2:3; And / or, in step S6, the weight ratio of LSCF powder to cerium oxide-doped zirconium oxide powder is 1.78:

1.

3. The method for preparing a planar anode-supported solid oxide fuel cell according to claim 1, characterized in that, In steps S1 to S3, as well as steps S5 and S6, the solvent is one or more of ethanol, butanone, and diethylene glycol monobutyl ether. The adhesive is one or more of polyvinyl butyral and ethyl cellulose; The plasticizer is one or more of dibutyl phthalate, polyethylene glycol, and bis(2-ethylhexyl) adipate; The dispersant is one or more of the following: stearic acid, fish oil, Span 83, dispersant KMT-3004, and dispersant BYK-110.

4. The method for preparing a planar anode-supported solid oxide fuel cell according to claim 2 or 3, characterized in that, In step S1, the mixture of nickel oxide powder, 3YSZ powder and 8YSZ powder comprises 54% by mass percentage (total of 100%), solvent 36%, binder 5%, plasticizer 4%, and dispersant 1%. And / or, in step S2, the mixture of 8YSZ powder and nickel oxide powder comprises 63% by weight, 32% by volume, 2% by volume, 2% by volume, and 1% by volume. And / or, in step S3, the total mass percentage is 70% 8YSZ powder, 24% solvent, 3% binder, 2% plasticizer, and 1% dispersant; And / or, in step S5, based on a total mass percentage of 100%, the composition is: 58.5% GDC powder, 1.5% iron oxide or cobalt oxide, 35% solvent, 2% binder, 2% plasticizer, and 1% dispersant; And / or, in step S6, the mixture of LSCF powder and cerium oxide-doped zirconium oxide powder is 71.6% by mass percentage, the solvent is 20%, the binder is 7%, the plasticizer is 1.2%, and the dispersant is 0.2%.

5. The method for preparing a planar anode-supported solid oxide fuel cell according to claim 1, characterized in that, In step S5, the iron oxide is FeO, Fe2O3, or Fe3O4; the cobalt oxide is CoO or Co2O3.

6. The method for preparing a planar anode-supported solid oxide fuel cell according to claim 1, characterized in that, In step S2, the screen printing of the anode functional layer is performed once or multiple times. In step S3, the electrolyte layer is screen printed once or multiple times. In step S5, the barrier layer is screen printed once or multiple times. In step S6, the cathode layer screen printing is performed once or multiple times.

7. The method for preparing a planar anode-supported solid oxide fuel cell according to any one of claims 1-3 and 5-6, characterized in that, In step S4, the specific process of debinding and sintering is as follows: from room temperature 2~5℃ / min to 450℃ and hold for 2h, then naturally cool to room temperature; then from room temperature 2~5℃ / min to 1400℃ and hold for 2h, then cool down to 450℃ at 2~5℃ / min and naturally cool to room temperature.

8. The method for preparing a planar anode-supported solid oxide fuel cell according to any one of claims 1-3 and 5-6, characterized in that, In step S4, during the debinding sintering, a zirconia plate is used as the firing plate, a porous alumina ceramic plate is used as the cover plate, and an anode support green body with an electrolyte layer and an anode functional layer is placed between the firing plate and the cover plate.

9. The method for preparing a planar anode-supported solid oxide fuel cell according to any one of claims 1-3 and 5-6, characterized in that, In step S7, when the half-cell with the barrier layer and the cathode layer is shaped and sintered, the temperature is 1050~1100℃ and the time is 2~3h.

10. A planar anode-supported solid oxide fuel cell, characterized in that, The solid oxide fuel cell is prepared by the method described in any one of claims 1 to 9. From bottom to top, the solid oxide fuel cell comprises an anode support, an anode functional layer, an electrolyte layer, a barrier layer, and a cathode layer. The thickness of the anode support is 380-400 μm; the thickness of the anode functional layer is 10-20 μm; the thickness of the electrolyte layer is 9-12 μm; the thickness of the barrier layer is 2-5 μm; and the thickness of the cathode layer is 20-30 μm.

Images