An anode self-supporting ultrathin solid oxide electrode and a preparation method thereof

Abstract

This invention discloses an anode-self-supporting ultrathin solid oxide electrode and its preparation method, belonging to the field of solid oxide electrode technology. The anode-self-supporting ultrathin solid oxide electrode comprises, from bottom to top: an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer. The anode functional layer is obtained by casting the anode functional layer slurry onto a metal support mesh or an inorganic support mesh and then drying it. The anode-self-supporting ultrathin solid oxide electrode significantly reduces the electrode thickness, lowers anode mass transfer polarization and ohmic polarization, enhances the internal heat transfer performance of the electrode, reduces start-up time, enhances the uniformity of electrode heat distribution, and improves electrode consistency performance.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide electrode technology, specifically relating to an anode self-supporting ultrathin solid oxide electrode and its preparation method. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are considered a promising sustainable energy device that efficiently and directly converts chemistry into electricity. Operating at 600–1000°C, SOFCs exhibit high ionic conductivity, fuel flexibility, and compatibility with inexpensive catalysts, converting the chemical energy stored in fuel directly into high-temperature electrical energy in a highly efficient, flexible, and environmentally friendly manner, achieving system efficiencies of up to 80%. SOFCs support a variety of fuels. In addition to hydrogen, which is ideal but expensive due to its reliance on hydrocarbon reforming, they can also directly utilize hydrocarbons such as natural gas, ammonia, and alcohols. These hydrocarbons are abundant and economically accessible, derived from fossil fuels such as oil and coal, as well as biomass.

[0003] Traditional solid oxide fuel cell electrodes are generally classified into three types: electrolyte-supported SOFC, anode-supported SOFC, and metal-supported SOFC. Since the mechanical strength of electrolyte-supported SOFC depends on the electrolyte layer, which is typically thicker, although this provides greater mechanical strength, it also increases oxygen ion conduction resistance and overall ohmic impedance. Therefore, it is not widely used currently.

[0004] Chinese patent CN 119340406 A discloses a method for preparing an anode sheet for a solid oxide fuel cell half-cell with anode support. The method includes: 1. Adding raw materials to a mixed solvent and ball-milling to obtain an anode slurry, then preparing an anode film strip using a one-time casting method; 2. Adding raw materials to an ethanol solvent and ball-milling to obtain an electrolyte slurry, then preparing an electrolyte film strip using a co-casting method; 3. Cutting and pressing the co-cast film strip to obtain an anode green blank; 4. Sintering the anode green blank to obtain an anode sheet for a solid oxide fuel cell half-cell with anode support. This invention uses a co-casting-temperature isostatic pressing process to prepare solid oxide fuel cells, improving the adhesion between the anode layer and the electrolyte layer, resulting in a solid oxide fuel cell half-cell anode sheet with higher flatness and mechanical strength, and a high sintering rate and good battery performance. However, the overall mechanical strength of the electrode in this invention is provided by the anode, whose anode film strip thickness is 400~500 μm. The thicker anode layer increases the mass transfer distance and electron transport distance, significantly increasing the battery's mass transfer polarization and ohmic polarization.

[0005] Chinese patent CN 103928693 A discloses a metal-supported half-cell for a solid oxide fuel cell and its preparation method. The half-cell comprises, from bottom to top, a porous metal support layer, a porous metal-ceramic gradient transition layer, a porous anode layer, and a dense electrolyte layer. The porous gradient transition layer composed of a mixed oxide and a fluorite-structured oxide avoids direct contact between the porous metal support layer and the porous anode layer, reducing the interdiffusion of Fe and Cr elements in the metal support layer and Ni elements in the porous anode layer under high-temperature sintering conditions. The mixed oxide is reduced to form an alloy under the battery's operating conditions: a highly anolyte material is formed at the anode side interface, and a highly conductive composite material with the alloy as the main phase is formed at the metal support side interface, exhibiting higher conductivity and lower ohmic resistance, while simultaneously achieving a good bond between the porous metal support layer and the porous anode layer. However, the metal support layer used in this invention is 200-1000 μm thick. The thicker metal support layer increases the mass transfer distance and electron transport distance, significantly increasing the battery's mass transfer polarization and ohmic polarization.

[0006] Existing technologies, whether anode-supported electrodes or metal-supported electrodes, increase the overall electrode thickness, increase the mass transfer distance, increase ohmic resistance, and reduce battery performance. At the same time, they also require more materials, increasing costs. Summary of the Invention

[0007] To address the aforementioned technical problems, this invention provides an anode-self-supporting ultrathin solid oxide electrode and its preparation method. The anode-self-supporting ultrathin solid oxide electrode significantly reduces the electrode thickness, lowers anode mass transfer polarization and ohmic polarization, enhances the internal heat transfer performance of the electrode, reduces start-up time, improves the uniformity of electrode heat distribution, and enhances electrode consistency performance.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] This invention provides an anode-self-supporting ultrathin solid oxide electrode, which comprises, from bottom to top: an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer; the anode functional layer is obtained by casting the anode functional layer slurry onto a metal support mesh or an inorganic support mesh and then drying it.

[0010] The metal support mesh is either Hastelloy woven mesh or Inconel nickel alloy wire mesh.

[0011] The inorganic support mesh is any one of ceramic-based support mesh, glass-based support mesh, or carbon-based support mesh.

[0012] The thickness of the metal support mesh or inorganic support mesh is 5~20 μm, and the mesh count is 20~3000 mesh.

[0013] The ceramic matrix support network is any one of alumina ceramic, silicon carbide ceramic, silicon nitride ceramic, zirconium oxide ceramic, or high-entropy boride ceramic support network.

[0014] The glass-based support mesh can be either a quartz glass support mesh or a borosilicate glass support mesh.

[0015] The carbon-based support mesh is either a porous glass carbon support mesh or a carbon fiber reinforced carbon support mesh.

[0016] The anode functional layer slurry is composed of solvent, dispersant, anode functional layer powder, binder, plasticizer, and pore-forming agent.

[0017] The anode functional layer powder accounts for 25-45% of the mass percentage of the anode functional layer slurry.

[0018] The solvent is any one or more of ethanol, methanol, n-propanol, isopropanol, DMF, ethylene glycol, propylene glycol, toluene, xylene, acetone, butanone, ethyl acetate, triethanolamine, polyethylene glycol, polyvinyl butyral, and dioctyl phthalate.

[0019] The anode functional layer powder is any one or more of nickel oxide, anti-carbon deposition alloy, and ion-conducting framework; the anti-carbon deposition alloy is Ni-Cu or Ni-Fe alloy; the ion-conducting framework is any one or more of YSZ, GDC, and SDC.

[0020] The binder is any one or more of starch, polyvinyl alcohol, polyvinyl butyral, polymethyl acrylate, polymethacrylate, and ethyl cellulose.

[0021] The plasticizer is any one or more of the following: dioctyl phthalate, dibutyl phthalate, DEHP (di(2-ethylhexyl) phthalate), DBP (di-n-butyl phthalate), DINP (diisononyl phthalate), TBC (tributyl citrate), ATBC (acetylated tributyl citrate), epoxidized soybean oil (ESO), epoxidized fatty acid esters, DOA (dioctyl adipate), and DOS (dioctyl sebacate); wherein the epoxidized fatty acid ester is dioctyl tetrahydroepoxy phthalate.

[0022] The pore-forming agent is any one or more of starch, graphite, polymethyl methacrylate (PMMA), ammonium carbonate, and ammonium bicarbonate.

[0023] The thickness of the self-supporting ultrathin solid oxide electrode is 60~80μm.

[0024] The present invention also provides a method for preparing the aforementioned anode self-supporting ultrathin solid oxide electrode, the method comprising the following steps:

[0025] (1) Preparation of anode functional layer: A metal support mesh or an inorganic support mesh is laid flat on the base film, and the anode functional layer slurry is prepared on the metal support mesh or an inorganic support mesh by casting method. After drying, the anode functional layer is formed.

[0026] (2) Electrolyte layer preparation: The electrolyte slurry is cast onto the surface of the anode functional layer, dried and cured, the scraps are cut off, and the half cell is obtained by stacking, hot pressing and debinding.

[0027] (3) Preparation of barrier layer and cathode functional layer: A barrier layer is screen printed on the above half cell, and then a cathode functional layer is screen printed through pre-sintering. Finally, the finished electrode is obtained by co-sintering.

[0028] The barrier layer is a GDC barrier layer.

[0029] The cathode functional layer is an LSCF cathode functional layer.

[0030] The anode self-supporting ultrathin solid oxide electrode provided by the present invention uses an ultrathin high-strength metal support mesh or inorganic support mesh as "steel bars" and an anode functional layer slurry as "concrete" to jointly construct the anode functional layer. Without affecting the catalytic effect of the anode functional layer, the mechanical properties of the electrode are enhanced by the ultrathin high-strength metal support mesh or inorganic support mesh, thereby eliminating the need for the anode support layer and using the anode functional layer for self-support.

[0031] Compared with the prior art, the present invention has the following beneficial effects:

[0032] The anode self-supporting ultrathin solid oxide electrode provided by this invention greatly reduces the electrode thickness by eliminating the need for a 400-500 μm thick anode support layer or a 200-1000 μm thick metal support layer. This reduces anode mass transfer polarization and ohmic polarization, enhances the internal heat transfer performance of the electrode, reduces start-up time, improves the uniformity of electrode heat distribution, and enhances electrode consistency performance. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the anode self-supporting ultrathin solid oxide electrode structure provided by the present invention;

[0034] Figure 2 A cross-sectional view of the anode functional layer in the anode self-supporting ultrathin solid oxide electrode provided by the present invention;

[0035] Figure 3 A plan view of the anode functional layer in the anode self-supporting ultrathin solid oxide electrode provided by the present invention;

[0036] Figure 4 This is a schematic diagram of the structure of a conventional anode-supported solid oxide electrode in Comparative Example 1;

[0037] Figure 5 This is a schematic diagram of the structure of a conventional metal-supported solid oxide electrode in Comparative Example 2;

[0038] Figure 6 The average thickness test diagram of the solid oxide electrode in each embodiment and comparative example;

[0039] Figure 7 The mechanical strength test diagrams of the solid oxide electrodes in each embodiment and comparative example are shown.

[0040] Figure 8 The graph shows the total conductivity of the vertical electrodes of the solid oxide electrodes in each embodiment and comparative example.

[0041] Figure 9 The in-plane conductivity test diagrams of the solid oxide electrodes in each embodiment and comparative example are shown.

[0042] Figure 10 The following are polarization curves of the solid oxide electrodes in each embodiment and comparative example. Detailed Implementation

[0043] In the description of this application, some directional terms, such as "upper", "lower", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0044] The present invention provides an anode self-supporting ultrathin solid oxide electrode, which comprises, from bottom to top, an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer; the anode functional layer is obtained by casting the anode functional layer slurry onto a metal support mesh or an inorganic support mesh and then drying it.

[0045] The thickness of the metal support mesh or inorganic support mesh is 5~20 μm, and the mesh count is 20~3000 mesh.

[0046] The metal support mesh can be selected as a high-strength metal mesh, preferably Hastelloy woven mesh or Incol nickel alloy wire mesh. The metal support mesh can be directly purchased from the market or prepared according to any method disclosed in the prior art. For example, a nickel-based metal support mesh can be prepared as follows: providing nickel-based high-temperature alloy wire, drawing it into ultra-fine wires with a diameter of less than 10μm through a multi-pass drawing process combined with intermediate annealing at 1100-1350℃, then weaving it into warp and weft, and performing micro-spot welding at the intersection of the warp and weft wires.

[0047] The inorganic support mesh can be any one of ceramic-based support mesh, glass-based support mesh, or carbon-based support mesh. Specifically, the ceramic-based support mesh can be any one of alumina ceramic, silicon carbide ceramic, silicon nitride ceramic, zirconium oxide ceramic, or high-entropy boride ceramic support mesh. The glass-based support mesh can be any one of quartz glass support mesh or borosilicate glass support mesh. The carbon-based support mesh can be any one of porous glass carbon support mesh or carbon fiber reinforced carbon support mesh. These can be directly purchased from the market or prepared according to any method disclosed in the prior art.

[0048] The anode functional layer paste can be any common type of anode paste, such as Ni-based cermet paste, specifically Ni-YSZ paste, Ni-GDC paste, Ni-SDC paste, Ni-LaGaO3-based paste; it can also be a Ni-free ceramic-based paste, such as LSCM paste, etc.

[0049] In embodiments of the present invention, the anode functional layer slurry is preferably composed of a solvent, a dispersant, anode functional layer powder, a binder, a plasticizer, and a pore-forming agent.

[0050] The anode functional layer powder accounts for 25-45% of the mass percentage of the anode functional layer slurry.

[0051] The anode functional layer powder is any one or more of nickel oxide, anti-carbon deposition alloy, and ion-conducting framework; the anti-carbon deposition alloy is Ni-Cu or Ni-Fe alloy; the ion-conducting framework is any one or more of YSZ, GDC, and SDC.

[0052] The solvent is any one or more of ethanol, methanol, n-propanol, isopropanol, DMF, ethylene glycol, propylene glycol, toluene, xylene, acetone, butanone, ethyl acetate, triethanolamine, polyethylene glycol, polyvinyl butyral, and dioctyl phthalate.

[0053] The binder is any one or more of starch, polyvinyl alcohol, polyvinyl butyral, polymethyl acrylate, polymethacrylate, and ethyl cellulose.

[0054] The plasticizer is any one or more of the following: dioctyl phthalate, dibutyl phthalate, DEHP (di(2-ethylhexyl) phthalate), DBP (di-n-butyl phthalate), DINP (diisononyl phthalate), TBC (tributyl citrate), ATBC (acetylated tributyl citrate), epoxidized soybean oil (ESO), epoxidized fatty acid esters, DOA (dioctyl adipate), and DOS (dioctyl sebacate); wherein the epoxidized fatty acid ester is dioctyl tetrahydroepoxy phthalate.

[0055] The pore-forming agent is any one or more of starch, graphite, polymethyl methacrylate (PMMA), ammonium carbonate, and ammonium bicarbonate.

[0056] The cathode functional layer slurry can be any common type of cathode slurry, such as perovskite oxide slurry, specifically LSM slurry, LSCF slurry, BSCF slurry; pyrochlore oxide slurry, layered oxide slurry.

[0057] The present invention will now be described in detail with reference to the embodiments.

[0058] All percentages mentioned in the examples are mass percentages.

[0059] The Inconel nickel alloy wire mesh and high-entropy boride ceramic support mesh used in the examples are commercially available.

[0060] Example 1

[0061] A self-supporting ultrathin solid oxide electrode for anodes comprises, from bottom to top: an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer; the anode functional layer is obtained by casting the anode functional layer slurry onto an Inconel nickel alloy wire mesh and then drying it.

[0062] The method for preparing the anode self-supporting ultrathin solid oxide electrode includes the following steps:

[0063] S1. Preparation of Anode Functional Layer Slurry: Under room temperature conditions, 31.92% ethanol, 11.97% nickel oxide, 27.93% 8YSZ, 1.60% polyvinyl alcohol, 2.00% polyvinyl butyral, 0.24% dioctyl phthalate, 24.14% polyethylene glycol, and 0.20% polymethyl methacrylate were sequentially added to a ball mill jar and ball milled to form a stable and uniform anode slurry. After obtaining the slurry, it was further filtered using a sieve with a pore size ≤20 μm to remove undispersed particles; then vacuum degassing was performed for 20-60 min to remove air bubbles introduced by stirring and filtration.

[0064] S2. Preparation of high-strength self-supporting anode functional layer: A 100-mesh, 10-μm thick Inconel nickel alloy wire mesh is laid horizontally and flat on the base film. The anode slurry is prepared onto the Inconel nickel alloy wire mesh by casting. A porous anode functional layer is formed by gradient drying. The gradient drying process is shown in Table 1. The heating rate of each gradient is 2℃ / min. The thickness of the anode functional layer is 18 μm.

[0065] Table 1

[0066]

[0067] S3. Preparation of electrolyte slurry: Under room temperature conditions, 26.3% YSZ, 14.2% ScCeSZ powder, 0.3% triethanolamine, 0.2% triethyl phosphate, 7.3% polyvinyl butyral, 2.8% ethyl cellulose, 1.6% dibutyl phthalate, 0.8% polyethylene glycol, 30.3% ethanol, and 16.2% methyl ethyl ketone are wet-mixed to obtain electrolyte slurry. The viscosity of the slurry is controlled at 2000-5000 mPa·s. The electrolyte slurry is then filtered and degassed to obtain electrolyte layer slurry.

[0068] S4. Electrolyte layer preparation: Electrolyte slurry is cast onto the surface of the anode functional layer with a casting thickness of 14μm. After drying and curing, the scraps are cut off, and the glue is removed by hot pressing. The hot pressing pressure is 10-35 MPa, the sintering temperature is 800~1800℃, and the half cell is obtained by cutting.

[0069] S5. Cathode functional layer construction: A GDC barrier layer is screen-printed on the above half cell, and then an LSCF cathode is screen-printed through pre-sintering. Finally, the finished electrode-1 is obtained through co-sintering.

[0070] Example 2

[0071] A self-supporting ultrathin solid oxide electrode for anodes comprises, from bottom to top: an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer; the anode functional layer is obtained by casting the anode functional layer slurry onto a high-entropy boride ceramic support mesh and then drying it.

[0072] The method for preparing the anode self-supporting ultrathin solid oxide electrode includes the following steps:

[0073] S1. Preparation of Anode Functional Layer Slurry: Under room temperature conditions, 31.92% ethanol, 11.97% nickel oxide, 27.93% 8YSZ, 1.60% polyvinyl alcohol, 2.00% polyvinyl butyral, 0.24% dioctyl phthalate, 24.14% polyethylene glycol, and 0.20% polymethyl methacrylate were sequentially added to a ball mill jar and ball milled to form a stable and uniform anode slurry. After obtaining the slurry, it was further filtered using a sieve with a pore size ≤20 μm to remove undispersed particles; then vacuum degassing was performed for 20-60 min to remove air bubbles introduced by stirring and filtration.

[0074] S2. Preparation of high-strength self-supporting anode functional layer: A high-entropy boride ceramic support mesh with a mesh size of 300 and a thickness of 8 μm is laid flat on the base film, and the mixed slurry is prepared on the high-strength support mesh by casting method. A porous anode functional layer is formed by gradient drying. The gradient drying process is shown in Table 1. The thickness of the anode functional layer is 16 μm.

[0075] S3. Preparation of electrolyte slurry: Under room temperature conditions, 26.3% YSZ, 14.2% ScCeSZ powder, 0.3% triethanolamine, 0.2% triethyl phosphate, 7.3% polyvinyl butyral, 2.8% ethyl cellulose, 1.6% dibutyl phthalate, 0.8% polyethylene glycol, 30.3% ethanol, and 16.2% methyl ethyl ketone are wet-mixed to obtain electrolyte slurry. The viscosity of the slurry is controlled at 2000-5000 mPa·s. The electrolyte slurry is then filtered and degassed to obtain electrolyte layer slurry.

[0076] S4. Electrolyte layer preparation: Electrolyte slurry is cast onto the surface of the anode functional layer with a casting thickness of 14μm. After drying and curing, the scraps are cut off, and the glue is removed by hot pressing. The hot pressing pressure is 10-35 MPa, the sintering temperature is 800~1800℃, and the half cell is obtained by cutting.

[0077] S5. Cathode functional layer construction: A GDC barrier layer is screen-printed on the above half cell, and then an LSCF cathode is screen-printed through pre-sintering. Finally, the finished electrode-2 is obtained through co-sintering.

[0078] Comparative Example 1

[0079] A method for preparing an anode-supported solid oxide electrode includes the following steps:

[0080] S1. Preparation of the anode support layer: Under room temperature conditions, 49% NiO (metallic phase), 25.4% 3YSZ (ceramic skeleton), 13% ethanol, 5.5% methyl ethyl ketone (MEK), 5.5% polyvinyl butyral, 0.4% triethanolamine, and 1.2% dibutyl phthalate (DEP) were sequentially added to a ball mill jar and ball milled for 4-8 hours. Then, 5% corn starch and 1% PMMA (by mass of the above raw materials) were added, and the mixture was ball milled again for 4 hours to obtain a stable and uniform anode support layer slurry. After obtaining the slurry, it was filtered through a sieve with a pore size ≤20 μm to remove undispersed particles. Then, vacuum degassing was performed for 20-60 minutes to remove air bubbles introduced by stirring and filtration. Finally, the anode support layer green sheet was obtained by casting, with a casting thickness of 200-500 μm, a drying temperature of 60-100℃, and a drying time of 3-12 hours.

[0081] S2. Preparation of the anode functional layer: Under room temperature conditions, 31.92% ethanol, 11.97% nickel oxide, 27.93% 8YSZ, 1.60% polyvinyl alcohol, 2.00% polyvinyl butyral, 0.24% dioctyl phthalate, 24.14% polyethylene glycol, and 0.20% polymethyl methacrylate were sequentially added to a ball mill jar and ball-milled to form a stable and uniform anode slurry. The slurry was then filtered and degassed to obtain the anode functional layer slurry. The slurry was used to prepare the anode functional layer electrode sheet by casting, and the anode functional layer was formed by gradient drying. The gradient drying process is shown in Table 1. The thickness of the anode functional layer is 10 μm.

[0082] S3. Preparation of electrolyte slurry: Under room temperature conditions, 26.3% YSZ, 14.2% ScCeSZ powder, 0.3% triethanolamine, 0.2% triethyl phosphate, 7.3% polyvinyl butyral, 2.8% ethyl cellulose, 1.6% dibutyl phthalate, 0.8% polyethylene glycol, 30.3% ethanol, and 16.2% methyl ethyl ketone are wet-mixed to obtain electrolyte slurry. The viscosity of the slurry is controlled at 2000-5000 mPa·s. The electrolyte slurry is then filtered and degassed to obtain electrolyte layer slurry.

[0083] S4. Electrolyte layer preparation: Electrolyte slurry is cast onto the surface of the anode functional layer with a thickness of 14μm. After drying and curing, the scraps are cut off. After stacking the anode support layer, the glue is removed by hot pressing. The hot pressing pressure is 10-35 MPa and the sintering temperature is 800~1800℃. The half cell is obtained by cutting.

[0084] S5. Cathode functional layer construction: A GDC barrier layer is screen-printed on the above half cell, and then an LSCF cathode is screen-printed through pre-sintering. Finally, the finished electrode is obtained through co-sintering - Comparison 1.

[0085] Comparative Example 2

[0086] A method for preparing a metal-supported solid oxide electrode includes the following steps:

[0087] S1: Preparation of the metal support layer: The nickel-iron-chromium-aluminum (Ni-Fe-Cr-Al) alloy is immersed in an etchant to dissolve the non-precious metal element aluminum (Al), while retaining the nickel / iron / chromium (Ni / Fe / Cr) to form a three-dimensional through-pore structure. The etchant consists of 20 vol% H3PO4, 30 mL / L HNO3, and 50 mL / L acetic acid. It is then immersed in the electrolyte slurry from step S3 for 1-5 minutes and dried.

[0088] S2: Preparation of the anode functional layer: Under room temperature conditions, 31.92% ethanol, 11.97% nickel oxide, 27.93% 8YSZ, 1.60% polyvinyl alcohol, 2.00% polyvinyl butyral, 0.24% dioctyl phthalate, 24.14% polyethylene glycol, and 0.20% polymethyl methacrylate were sequentially added to a ball mill jar and ball-milled to form a stable and uniform anode slurry. After obtaining the slurry, it was filtered and degassed to obtain the anode functional layer slurry. The slurry was cast onto a metal support layer to obtain an anode functional layer electrode sheet, and a porous anode layer was formed by gradient drying. The gradient drying process is shown in Table 1. The thickness of the anode layer is 10 μm.

[0089] S3. Preparation of electrolyte slurry: Under room temperature conditions, 26.3% YSZ, 14.2% ScCeSZ powder, 0.3% triethanolamine, 0.2% triethyl phosphate, 7.3% polyvinyl butyral, 2.8% ethyl cellulose, 1.6% dibutyl phthalate, 0.8% polyethylene glycol, 30.3% ethanol, and 16.2% methyl ethyl ketone are wet-mixed to obtain electrolyte slurry. The viscosity of the slurry is controlled at 2000-5000 mPa·s. The electrolyte slurry is then filtered and degassed to obtain electrolyte layer slurry.

[0090] S4. Electrolyte layer preparation: Electrolyte slurry is cast onto the surface of the anode functional layer with a thickness of 14μm. After drying and curing, the scraps are cut off, and a metal support layer is stacked. The adhesive is removed by hot pressing at a pressure of 10-35 MPa and a sintering temperature of 800-1800℃. The half cell is obtained by cutting.

[0091] S5. Cathode functional layer construction: A GDC barrier layer is screen-printed on the above half cell, and then an LSCF cathode is screen-printed through pre-sintering. Finally, the finished electrode is obtained through co-sintering - Comparison 2.

[0092] Test case

[0093] The four samples were subjected to thickness testing, mechanical strength testing, thermal conductivity testing, electrical conductivity testing, and battery performance testing to characterize the physical properties and battery performance of the four samples.

[0094] The thickness test references the thickness uniformity test method in the standard "NB / T 10670-2021 Solid Oxide Fuel Cell Electrolyte Membrane Test Method Part 1: Self-Supporting Membrane" to test the sample thickness.

[0095] The mechanical strength test references section 8.2, Membrane Strength Test Method, of the standard "NB / T 10670-2021 Solid Oxide Fuel Cell Electrolyte Membrane Test Method Part 1: Self-Supporting Membrane", and tests the mechanical strength of the sample.

[0096] The conductivity test references the conductivity test method in section 9 of the standard "NB / T 10670-2021 Solid Oxide Fuel Cell Electrolyte Membrane Test Method Part 1: Self-Supporting Membrane". The electrode conductivity is tested using the four-probe test method to test the in-plane conductivity.

[0097] The thermal conductivity was tested according to the "GB T10294-2008 Determination of Steady-State Thermal Resistance and Related Properties of Insulation Materials - Protective Hot Plate Method" for testing the phase and in-plane thermal conductivity using the electrode method.

[0098] Test results are as follows Figure 6-10 As shown.

[0099] from Figure 6 As can be seen from the data, the thickness of the solid oxide electrodes in Examples 1 and 2 decreased from 300 μm to about 70 μm compared to Comparative Examples 1 and 2, which is about 76% thinner. This is beneficial for reducing mass transfer polarization and ohmic polarization.

[0100] from Figure 7 As can be seen, although the thickness of the solid oxide electrodes in Examples 1 and 2 is significantly reduced compared to Comparative Examples 1 and 2, the mechanical strength is slightly improved. This is because the metal support mesh or inorganic support mesh adopted in this invention has high strength, which can improve the mechanical strength.

[0101] from Figure 8 As can be seen, although the thickness of the solid oxide electrodes in Examples 1 and 2 is significantly reduced compared to Comparative Examples 1 and 2, the vertical conductivity does not change much.

[0102] from Figure 9 As can be seen from the data, compared with Example 2 and Comparative Examples 1 and 2, Example 1 has a higher in-plane conductivity, which is due to the high conductivity of the Inconel alloy wire mesh.

[0103] from Figure 10As can be seen, as the current density increases from 0 to 2000 mA·cm⁻², the voltage drop of Examples 1 and 2 is smaller, and they can still maintain the voltage in the range of 0.55–0.6V at high current densities. In contrast, the voltage drop of Comparative Examples 1 and 2 is larger, especially Comparative Example 2, which has a voltage close to 0.5V at high current densities. This indicates that Examples 1 and 2 have stronger anti-polarization capabilities and can maintain a higher output voltage under high current conditions. It is evident that Examples 1 and 2 have better electrochemical performance than Comparative Examples 1 and 2.

[0104] The above detailed description of an anode-self-supporting ultrathin solid oxide electrode and its preparation method, with reference to the embodiments, is illustrative rather than limiting. Several embodiments may be listed within the defined scope. Therefore, variations and modifications without departing from the overall concept of the present invention should be within the protection scope of the present invention.

Claims

1. A self-supporting ultrathin solid oxide electrode, characterized in that, The self-supporting ultrathin solid oxide electrode comprises, from bottom to top: an anode functional layer, an electrolyte layer, a barrier layer, and a cathode functional layer; the anode functional layer is obtained by casting the anode functional layer slurry onto a metal support mesh or an inorganic support mesh and then drying it.

2. The anode self-supporting ultrathin solid oxide electrode according to claim 1, characterized in that, The metal support mesh is either Hastelloy woven mesh or Inconel nickel alloy wire mesh.

3. The anode self-supporting ultrathin solid oxide electrode according to claim 1, characterized in that, The inorganic support mesh is any one of ceramic-based support mesh, glass-based support mesh, or carbon-based support mesh.

4. The anode self-supporting ultrathin solid oxide electrode according to claim 1, characterized in that, The thickness of the metal support mesh or inorganic support mesh is 5~20 μm, and the mesh count is 20~3000 mesh.

5. The anode self-supporting ultrathin solid oxide electrode according to claim 1, characterized in that, The anode functional layer slurry is composed of solvent, dispersant, anode functional layer powder, binder, plasticizer, and pore-forming agent.

6. The anode self-supporting ultrathin solid oxide electrode according to claim 5, characterized in that, The anode functional layer powder accounts for 25-45% of the mass percentage of the anode functional layer slurry.

7. The anode self-supporting ultrathin solid oxide electrode according to claim 1, characterized in that, The thickness of the self-supporting ultrathin solid oxide electrode is 60~80μm.

8. The method for preparing the anode self-supporting ultrathin solid oxide electrode as described in claim 1, characterized in that, The preparation method includes the following steps: (1) Preparation of anode functional layer: A metal support mesh or an inorganic support mesh is laid flat on the base film, and the anode functional layer slurry is prepared on the metal support mesh or an inorganic support mesh by casting method. After drying, the anode functional layer is formed. (2) Electrolyte layer preparation: The electrolyte slurry is cast onto the surface of the anode functional layer, dried and cured, the scraps are cut off, and the half cell is obtained by stacking, hot pressing and debinding. (3) Preparation of barrier layer and cathode functional layer: A barrier layer is screen printed on the above half cell, and then a cathode functional layer is screen printed through pre-sintering. Finally, the finished electrode is obtained by co-sintering.

9. The preparation method according to claim 8, characterized in that, The barrier layer is a GDC barrier layer.

10. The preparation method according to claim 8, characterized in that, The cathode functional layer is an LSCF cathode functional layer.

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