Preparation method of large-size single cell sheet for SOEC

Abstract

The application provides application of a hydrogen electrode support in preparation of a single cell sheet of an SOEC; the hydrogen electrode support comprises, in terms of raw materials, nickel oxide, yttrium oxide stabilized zirconium oxide, pore-forming agent graphite, a binder, a plasticizer and a solvent; the application also provides a large-size single cell sheet preparation method with stable process, improves the structural integrity of the support, eliminates defects such as internal pores and microcracks, and enhances the mechanical strength and air tightness of the cell sheet; improves the coating process and slurry dispersibility of the electrode and the electrolyte layer, realizes precise thickness control of each functional layer on the large-size substrate, promotes uniform dispersion of the active material, guarantees the consistency of the electrical conductivity and catalytic activity of different regions of the cell sheet, and improves the overall electrolysis performance stability; adapts the organic carrier composition and sintering shrinkage characteristics of each functional layer, releases thermal stress, reduces interface defects such as interlayer peeling and warping deformation, strengthens the bonding strength between the functional layers, and prolongs the service life of the cell.

Description

Technical Field

[0001] This invention belongs to the field of hydrogen electrode preparation technology for SOEC cells, and relates to the application of hydrogen electrode support in the preparation of SOEC single cell cells and a method for preparing SOEC single cell cells, especially a method for preparing large-size single cell cells for SOEC. Background Technology

[0002] With the global energy structure transitioning towards cleaner and lower-carbon energy, hydrogen energy, as a highly efficient and environmentally friendly secondary energy carrier, is increasingly widely used in fuel cell power generation, industrial hydrogen refueling, and transportation. Its large-scale production has become a research hotspot in the energy sector. Solid oxide electrolyzers (SOECs), with their advantages of high electrolysis efficiency, high product purity, and the ability to utilize waste heat from chemical and nuclear reactions to achieve green hydrogen production, have become an important development direction for current hydrogen production technologies. The core component of an SOEC system is the individual solar cell, and its size directly affects the system's integration efficiency and cost control. Larger individual solar cells can reduce the number of cells connected in series / parallel in the stack, lower sealing difficulty and contact resistance, thereby improving the overall energy density and operational stability of the system. Therefore, developing large-size SOEC individual solar cells is a key step in promoting the industrialization of SOEC technology.

[0003] However, the fabrication of large-size single-cell solar cells faces significant technical challenges: compared to small-size cells, large-size structures place higher demands on the structural integrity, interfacial bonding strength, and performance uniformity of each functional layer (support, anode, electrolyte, and cathode). Currently, the fabrication of large-size solar cells is largely based on traditional ceramic molding processes, but these processes have gradually revealed numerous problems in practical applications. The support, as the structural foundation of the solar cell, directly affects the cell's stability due to its density and mechanical strength; existing molding processes easily lead to defects such as pores and cracks within the support. During the coating process of the electrode and electrolyte layers, uneven dispersion of the slurry on the large-size substrate and difficulty in thickness control can easily cause an imbalance in the distribution of active materials, resulting in significant differences in electrocatalytic performance in different regions of the solar cell. Insufficient matching of sintering process parameters for each functional layer, coupled with differences in the thermal expansion coefficients between different materials during high-temperature treatment, can easily lead to thermal stress concentration, resulting in solar cell deformation, interlayer delamination, and even gas leakage. Furthermore, existing fabrication processes are mostly step-by-step operations, with long production cycles and poor process stability, leading to low yields and difficulty in meeting the mass supply requirements of large-size solar cells for large-scale SOEC system applications. These problems severely restrict the industrialization of SOEC technology.

[0004] Existing research proposals also disclose methods for preparing large-size SOEC single-cell solar cells using a combination of casting, screen printing, and co-sintering. This method is currently the mainstream technology for preparing large-size SOEC solar cells in the industry. While this existing technology combines casting and screen printing to achieve the molding and composite of various functional layers in large-size solar cells, it still suffers from the following drawbacks: First, uneven slurry flow during the casting process can easily lead to microcracks within the support, which further expand during subsequent co-sintering, resulting in poor structural integrity of the solar cell. Second, the screen printing process has limited precision in controlling the thickness uniformity of large-size substrates, leading to agglomeration of electrode active materials and large fluctuations in electrolyte layer thickness, resulting in poor uniformity of the solar cell. Third, mismatches in the organic carrier composition and sintering shrinkage rate of each functional layer result in significant thermal stress concentration during co-sintering, easily causing interlayer delamination or solar cell warping. Fourth, the step-by-step drying and multiple sintering processes lead to long production cycles and low yields, making it difficult to meet the needs of large-scale production.

[0005] Therefore, developing a more suitable method for preparing large-size single-cell solar cells that can overcome the bottlenecks in existing preparation processes is of great practical significance and is one of the problems that many forward-looking researchers in this field urgently need to solve. Summary of the Invention

[0006] In view of this, the technical problem to be solved by the present invention is to provide the application of hydrogen electrode support in the preparation of SOEC single-cell solar cells and a method for preparing SOEC single-cell solar cells, particularly a method for preparing large-size SOEC single-cell solar cells. The large-size single-cell solar cell preparation method provided by the present invention has solved the core problems such as support structure defects, insufficient performance uniformity, poor process matching, and low efficiency of large-scale production; moreover, the preparation method is simple, has good controllability, and is suitable for industrial promotion and application.

[0007] This invention provides the application of hydrogen electrode support in the fabrication of SOEC single-cell solar cells;

[0008] The hydrogen electrode support, based on raw materials, includes: nickel oxide, yttrium-stabilized zirconium oxide, pore-forming agent graphite, binder, plasticizer, and solvent;

[0009] The mass ratio of nickel oxide to yttrium oxide-stabilized zirconium oxide is (5~7):(5~3);

[0010] The pore-forming agent graphite comprises 2% to 5% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide.

[0011] Preferably, the adhesive comprises polyvinyl butyral and / or polyvinylpyrrolidone;

[0012] The amount of the binder is 4 wt% to 10 wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide;

[0013] The plasticizer includes polyethylene glycol PEG400 and / or dibutyl phthalate;

[0014] The amount of plasticizer used is 4 wt% to 10 wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide;

[0015] The applications include increasing the flexibility and / or ductility of the green cast strip.

[0016] The applications include enhancing the mechanical strength and / or airtightness of solar cells.

[0017] Preferably, the solvent includes anhydrous ethanol;

[0018] The individual solar cells include large-size individual solar cells;

[0019] The dimensions of the individual battery are 15cm*15cm;

[0020] The hydrogen electrode support is prepared by a casting process;

[0021] The applications include one or more of the following: improving the structural integrity of the support, eliminating internal pores in the support, and eliminating microcracks in the support.

[0022] This invention provides a method for preparing SOEC single-cell solar cells, comprising the following steps:

[0023] 1) Nickel oxide, yttrium oxide-stabilized zirconium oxide, pore-forming agent graphite and solvent are mixed and ball-milled to obtain a pre-mixed powder. A binder is then added and mixed, followed by the addition of a plasticizer and ball-milling to obtain a slurry.

[0024] 2) After defoaming the slurry obtained in the above steps, it is cast into a film and dried to obtain a hydrogen electrode support blank;

[0025] 3) Prepare hydrogen electrode functional layer slurry and electrolyte slurry. First, screen print hydrogen electrode functional layer slurry on the hydrogen electrode support blank obtained in the above steps, then screen print electrolyte slurry, and then air dry to obtain hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blank.

[0026] 4) Using a yttrium-stabilized zirconia porous sintering plate, the hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blanks obtained in the above steps are subjected to degreasing heat treatment and two sintering processes to obtain a half cell, which is then used to prepare a single cell.

[0027] Preferably, the mass ratio of nickel oxide to yttrium-stabilized zirconium oxide is (5~7):(5~3);

[0028] The particle size of the pore-forming agent graphite is 800~1500 mesh;

[0029] In the preparation of the pre-mixed powder, the ratio of the volume of the solvent to the total mass of nickel oxide and yttrium-stabilized zirconium oxide is 0.3~0.8 mL / g;

[0030] The mixing and ball milling time is 8~24 hours;

[0031] The rotation speed of the mixing ball mill is 100~400 rpm.

[0032] Preferably, the molar content of yttrium oxide in the yttrium-stabilized zirconium oxide is 3% to 8%;

[0033] The ball milling time is 24~48 hours;

[0034] The ball mill rotates at a speed of 200-300 rpm;

[0035] The height of the casting cutter head in the casting process is 2~3mm;

[0036] The casting speed is 0.5~2cm / s.

[0037] Preferably, the hydrogen electrode functional layer slurry comprises terpineol composite solvent and hydrogen electrode material;

[0038] The electrolyte slurry includes terpineol composite solvent and electrolyte material;

[0039] The terpineol composite solvent includes terpineol solvent, ethyl cellulose, binder, and plasticizer;

[0040] The hydrogen electrode material includes nickel oxide and yttrium oxide-stabilized zirconium oxide;

[0041] The electrolyte material includes yttrium-stabilized zirconium oxide.

[0042] Preferably, the mass content of nickel oxide in the hydrogen electrode functional layer slurry is 30% to 40%.

[0043] In the hydrogen electrode functional layer slurry, the mass content of yttrium oxide-stabilized zirconium oxide is 30%~40%;

[0044] In the electrolyte slurry, the mass content of the electrolyte material is 60%~70%;

[0045] The screen printing stencil has an aperture of 280-380 mesh.

[0046] The degreasing heat treatment includes a rapid heating stage, a stepped heating stage, a high-temperature constant temperature stage, and a controlled-rate cooling stage.

[0047] The temperature cutoff point for the rapid heating in the front section is 80~120℃;

[0048] The rapid heating time in the front section is ≥200 min;

[0049] The heating rate of the intermediate stepped heating section is 0.1~0.5℃ / min;

[0050] The intermediate-section stepped heating time is ≥1080 min;

[0051] The number of step points in the intermediate stage of stepped heating is 3 to 5;

[0052] The intermediate stepped heating stage has a constant temperature section at the step point before the high temperature constant temperature point, and the constant temperature section lasts for ≥120 minutes.

[0053] The temperature for the high-temperature constant temperature is 220~260℃;

[0054] The time for maintaining the high temperature is ≥240 min;

[0055] The temperature cutoff point for the controlled-speed cooling is 50~100℃;

[0056] The cooling time for the controlled-speed cooling is ≥260 min.

[0057] Preferably, the two sintering processes include a first degreasing sintering and a second tempering and pressing.

[0058] The first degreasing sintering includes segmented heating, high-temperature holding and stepped cooling;

[0059] The segmented heating includes a first heating segment, a first constant temperature segment, a second heating segment, a second constant temperature segment, a third variable speed heating segment, a third constant temperature segment, a fourth heating segment, a fourth constant temperature segment, and a fifth heating segment;

[0060] The cutoff temperature of the first heating stage is 230~270℃;

[0061] The duration of the first heating stage is ≥400 min;

[0062] The heat preservation time of the first constant temperature section is ≥120 min;

[0063] The cutoff temperature of the second heating stage is 440~460℃;

[0064] The duration of the second heating stage is ≥200 min;

[0065] The heat preservation time of the second constant temperature section is ≥60min;

[0066] The cutoff temperature of the third variable-speed heating section is 1130~1170℃;

[0067] The duration of the third variable-speed heating stage is ≥850 min;

[0068] The heating rate of the third variable-speed heating section is 0.2~3℃ / min;

[0069] The number of speed change points in the third variable speed heating section is 3 to 5;

[0070] The heat preservation time of the third constant temperature section is ≥120 min;

[0071] The cutoff temperature of the fourth heating stage is 1230~1270℃;

[0072] The duration of the fourth heating stage is ≥400 min;

[0073] The heat preservation time of the fourth constant temperature section is ≥120 min;

[0074] The duration of the fifth heating stage is ≥560 min;

[0075] The high-temperature insulation temperature is 1370~1410℃;

[0076] The high-temperature insulation time is ≥240 min;

[0077] The cutoff temperature for the first step of the stepped cooling is 1080~1120℃;

[0078] The first step of the stepped cooling process takes ≥200 min.

[0079] The first step of the stepped cooling process maintains a constant temperature at the cutoff temperature for ≥120 min.

[0080] The cutoff temperature for the second step of the stepped cooling is 680~720℃;

[0081] The second step of the stepped cooling process takes ≥200 min.

[0082] The stepped cooling process proceeds naturally after the cutoff temperature of the second step.

[0083] Preferably, the second tempering and pressing includes segmented heating, high-temperature holding and variable-speed cooling;

[0084] The segmented heating includes a first heating segment, a first constant temperature segment, and a second heating segment;

[0085] The cutoff temperature of the first heating stage is 980~1020℃;

[0086] The duration of the first heating stage is ≥475 min;

[0087] The heat preservation time of the first constant temperature section is ≥60min;

[0088] The duration of the second heating stage is ≥360 min;

[0089] The high-temperature insulation temperature is 1340~1380℃;

[0090] The high-temperature insulation time is ≥300 min;

[0091] The temperature cutoff point for the variable-speed cooling is 680~720℃;

[0092] The cooling rate of the variable-speed cooling is 1~4℃ / min;

[0093] The cooling time for the variable speed cooling is ≥280 min;

[0094] The variable speed cooling has 1 to 2 speed change points;

[0095] The preparation process in step 4) includes the following steps:

[0096] Configure the barrier layer slurry and the oxygen electrode layer slurry;

[0097] The barrier layer paste is screen-printed onto the electrolyte layer preform of the half-cell, and sintered to obtain the barrier layer preform. Then, the oxygen electrode layer paste is screen-printed onto the barrier layer preform, and sintered again to obtain the single cell.

[0098] This invention provides the application of a hydrogen electrode support in the preparation of SOEC single-cell solar cells; the hydrogen electrode support, based on raw materials, comprises: nickel oxide, yttrium-stabilized zirconium oxide, pore-forming agent graphite, binder, plasticizer, and solvent; the mass ratio of nickel oxide to yttrium-stabilized zirconium oxide is (5~7):(5~3); the pore-forming agent graphite accounts for 2%~5% of the total mass of nickel oxide and yttrium-stabilized zirconium oxide. Compared with existing technologies, this invention addresses several key bottlenecks in the fabrication process of existing SOEC large-size single-cell solar cells: the support is prone to structural defects such as cracking and insufficient density, and the bonding stability between the electrode and electrolyte layers and the support is poor, easily leading to gas leakage problems; at the same time, the uneven dispersion of electrode active materials and significant fluctuations in electrolyte layer thickness under large-size structures result in large differences in electrical performance in different regions of the solar cell, making it difficult to ensure overall performance uniformity; in addition, the matching degree between the fabrication processes of various functional layers such as the support, anode, electrolyte, and cathode (such as casting, coating, and sintering) is insufficient, and thermal stress is easily generated during high-temperature treatment, which in turn causes solar cell deformation; moreover, existing fabrication methods generally suffer from low production efficiency and low yield, making it difficult to meet the large-scale mass production requirements of SOEC systems for large-size solar cells. This invention identifies the following main drawbacks of existing technologies in practical applications: 1. Insufficient structural integrity of the support: Existing technologies use a combination of tape casting and sintering to prepare the support, which easily leaves pores inside after sintering. Simultaneously, the flowability of the slurry is difficult to control during tape casting, easily leading to microcracks in the support blank. These cracks further expand during subsequent co-sintering, ultimately resulting in insufficient structural strength of large-size solar cells, making them prone to breakage or gas leakage. 2. Poor uniformity of solar cell performance: When the electrode and electrolyte layers are coated using screen printing, the slurry spread unevenly on large-size substrates, and the active materials tend to agglomerate, leading to an imbalance in the dispersion of active materials in the electrodes. Furthermore, the large fluctuations in electrolyte layer thickness result in significant differences in conductivity and electrocatalytic activity in different areas of the solar cell, making it difficult to guarantee the overall consistency of electrolytic performance.

[0099] Based on this, the present invention specifically designs a hydrogen electrode support with a specific structure and composition for use in the preparation of SOEC single-cell solar cells. The present invention also provides a stable method for preparing large-size single-cell solar cells. First, it optimizes the support preparation process and slurry formulation to improve the structural integrity of the support, eliminate internal pores and microcracks, enhance the mechanical strength and airtightness of the solar cell, and prevent breakage or gas leakage during operation. Second, it improves the coating process of the electrode and electrolyte layers and the slurry dispersion, achieving precise control of the thickness of each functional layer on the large-size substrate, promoting uniform dispersion of active materials, ensuring consistency of conductivity and catalytic activity in different areas of the solar cell, and improving the overall electrolytic performance stability. Third, it adapts the organic carrier composition and sintering shrinkage characteristics of each functional layer, optimizes the thermal processing parameters to release thermal stress, reduce interfacial defects such as interlayer peeling and warping deformation, strengthen the bonding strength between functional layers, and extend the battery life. The present invention improves process stability and repeatability, increases yield, and meets the mass supply requirements of large-size solar cells for the industrialization of SOEC systems.

[0100] The SOEC single-cell solar cell prepared by this invention improves the structural integrity of the support: by optimizing the slurry formulation and ball milling and defoaming processes, porosity and microcracks within the support are eliminated, enhancing mechanical strength and airtightness, and preventing breakage and gas leakage. It ensures the uniformity of cell performance: uniform slurry dispersion and precise coating thickness result in balanced distribution of electrode active materials, consistent conductivity and catalytic activity across regions, and improved electrolytic performance stability. It strengthens interlayer bonding and structural stability: adapting to the sintering shrinkage characteristics of each functional layer, and releasing thermal stress through customized sintering curves, it reduces defects such as warpage and interlayer delamination, extending cell lifespan. Furthermore, it is suitable for large-scale production: simplifying step-by-step operation processes improves process stability and repeatability, increases yield, and meets the batch supply requirements of SOEC systems for large-size solar cells. Attached Figure Description

[0101] Figure 1 A schematic diagram of the processing flow of the hydrogen electrode support pre-powder provided by the present invention;

[0102] Figure 2 A simplified schematic diagram of the process flow for preparing and casting the hydrogen electrode support casting slurry provided by the present invention;

[0103] Figure 3 A simplified schematic diagram illustrating the preparation and printing process of the hydrogen electrode functional layer paste provided by this invention;

[0104] Figure 4 A simplified schematic diagram illustrating the preparation and printing process of the electrolyte layer slurry provided by this invention;

[0105] Figure 5The adhesive removal temperature curve of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention;

[0106] Figure 6 A primary sintering temperature curve of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention;

[0107] Figure 7 The secondary sintering and tempering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention.

[0108] Figure 8 A simplified schematic diagram illustrating the preparation and printing process of the barrier layer paste provided by this invention;

[0109] Figure 9 Sintering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer provided by the present invention;

[0110] Figure 10 A simplified schematic diagram illustrating the preparation and printing process of the oxygen electrode layer paste provided by this invention;

[0111] Figure 11 Sintering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer / oxygen electrode provided by the present invention;

[0112] Figure 12 This is a scanning electron microscope image of the battery prepared according to the present invention. Detailed Implementation

[0113] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims.

[0114] There are no particular restrictions on the source of any raw materials used in this invention; they can be purchased from the market or prepared using conventional methods known to those skilled in the art.

[0115] There are no particular restrictions on the purity of any raw materials used in this invention. However, this invention preferably uses analytical grade or conventional purity used in the preparation of hydrogen electrodes for solid oxide electrolytic cells.

[0116] This invention provides the application of hydrogen electrode support in the fabrication of SOEC single-cell solar cells;

[0117] The hydrogen electrode support, based on raw materials, includes: nickel oxide, yttrium-stabilized zirconium oxide, pore-forming agent graphite, binder, plasticizer, and solvent;

[0118] The mass ratio of nickel oxide to yttrium oxide-stabilized zirconium oxide is (5~7):(5~3);

[0119] The pore-forming agent graphite comprises 2% to 5% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide.

[0120] In this invention, the mass ratio of nickel oxide to yttrium oxide-stabilized zirconium oxide is (5~7):(5~3), which can be (5.4~6.6):(4.6~3.4), or (5.8~6.2):(4.2~3.8).

[0121] In this invention, the pore-forming agent graphite is 2% to 5% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide, which can be 2.5% to 4.5% or 3% to 4%.

[0122] In this invention, the adhesive preferably comprises polyvinyl butyral and / or polyvinylpyrrolidone, more preferably polyvinyl butyral or polyvinylpyrrolidone.

[0123] In this invention, the amount of the binder can be 4wt% to 10wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide, or 5wt% to 9wt% or 6wt% to 8wt%.

[0124] In this invention, the plasticizer preferably includes polyethylene glycol PEG400 and / or dibutyl phthalate, more preferably polyethylene glycol PEG400 or dibutyl phthalate.

[0125] In this invention, the amount of plasticizer can be 4wt% to 10wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide, or 5wt% to 9wt% or 6wt% to 8wt%.

[0126] In this invention, the application preferably includes the application of increasing the flexibility and / or ductility of the green cast strip, and more preferably the application of increasing the flexibility or ductility of the green cast strip.

[0127] In this invention, the application preferably includes applications in enhancing the mechanical strength and / or airtightness of the battery cell, and more preferably applications in enhancing the mechanical strength or airtightness of the battery cell.

[0128] In this invention, the solvent preferably includes anhydrous ethanol.

[0129] In this invention, the individual solar cell preferably includes a large-size individual solar cell.

[0130] In this invention, the size of the single battery cell can be 15cm*15cm.

[0131] In this invention, the hydrogen electrode support is preferably prepared by tape casting.

[0132] In this invention, the application preferably includes one or more of improving the structural integrity of the support, eliminating internal pores of the support, and eliminating microcracks in the support, and more preferably multiple of improving the structural integrity of the support, eliminating internal pores of the support, and eliminating microcracks in the support.

[0133] This invention provides a method for preparing SOEC single-cell solar cells, comprising the following steps:

[0134] 1) Nickel oxide, yttrium oxide-stabilized zirconium oxide, pore-forming agent graphite and solvent are mixed and ball-milled to obtain a pre-mixed powder. A binder is then added and mixed, followed by the addition of a plasticizer and ball-milling to obtain a slurry.

[0135] 2) After defoaming the slurry obtained in the above steps, it is cast into a film and dried to obtain a hydrogen electrode support blank;

[0136] 3) Prepare hydrogen electrode functional layer slurry and electrolyte slurry. First, screen print hydrogen electrode functional layer slurry on the hydrogen electrode support blank obtained in the above steps, then screen print electrolyte slurry, and then air dry to obtain hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blank.

[0137] 4) Using a yttrium-stabilized zirconia porous sintering plate, the hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blanks obtained in the above steps are subjected to degreasing heat treatment and two sintering processes to obtain a half cell, which is then used to prepare a single cell.

[0138] The present invention first mixes and ball-mills nickel oxide, yttrium oxide-stabilized zirconium oxide, pore-forming agent graphite and solvent to obtain a pre-mixed powder, then adds a binder and mixes it, and finally adds a plasticizer and ball-mills it to obtain a slurry.

[0139] In this invention, the mass ratio of nickel oxide to yttrium-stabilized zirconium oxide can be (5~7):(5~3), (5.4~6.6):(4.6~3.4), or (5.8~6.2):(4.2~3.8).

[0140] In this invention, the particle size of the pore-forming agent graphite can be 800~1500 mesh, 900~1400 mesh, 1000~1300 mesh, or 1100~1200 mesh, specifically 1200 mesh.

[0141] In this invention, the ratio of the volume of the solvent to the total mass of nickel oxide and yttrium-stabilized zirconium oxide in the preparation of the pre-mixed powder can be 0.3~0.8 mL / g, 0.4~0.7 mL / g, or 0.5~0.6 mL / g.

[0142] In this invention, the mixing and ball milling time can be 8~24h, 11~21h, or 14~17h.

[0143] In this invention, the rotation speed of the mixing ball mill can be 100~400 rpm, 150~350 rpm, or 200~300 rpm.

[0144] In this invention, the molar content of yttrium oxide in the yttrium oxide-stabilized zirconium oxide can be 3%~8%, 4%~7%, or 5%~6%.

[0145] In this invention, the ball milling time can be 24~48h, 30~45h, or 35~40h.

[0146] In this invention, the rotational speed of the ball mill can be 200~300 rpm, 220~280 rpm, 240~260 rpm, or 250 rpm.

[0147] The present invention involves defoaming the slurry obtained in the above steps, casting it, and drying it to obtain a hydrogen electrode support blank.

[0148] In this invention, the height of the casting cutter head for casting can be 2~3mm, 2.2~2.8mm, or 2.4~2.6mm.

[0149] In this invention, the casting speed of the casting process can be 0.5~2cm / s, 0.8~1.7cm / s, or 1.1~1.4cm / s.

[0150] The present invention then prepares a hydrogen electrode functional layer slurry and an electrolyte slurry. The hydrogen electrode functional layer slurry is first screen-printed on the hydrogen electrode support blank obtained in the above steps, and then the electrolyte slurry is screen-printed. After drying, a hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blank is obtained.

[0151] In this invention, the hydrogen electrode functional layer slurry preferably includes terpineol composite solvent and hydrogen electrode material.

[0152] In this invention, the electrolyte slurry preferably comprises a terpineol composite solvent and an electrolyte material.

[0153] In this invention, the terpineol composite solvent preferably includes terpineol solvent, ethyl cellulose, binder and plasticizer.

[0154] In this invention, the hydrogen electrode material preferably includes nickel oxide and yttrium oxide-stabilized zirconium oxide.

[0155] In this invention, the electrolyte material preferably comprises yttrium-stabilized zirconium oxide.

[0156] In this invention, the mass content of nickel oxide in the hydrogen electrode functional layer slurry can be 30%~40%, 32%~38%, or 34%~36%.

[0157] In this invention, the mass content of yttrium oxide-stabilized zirconium oxide in the hydrogen electrode functional layer slurry can be 30%~40%, 32%~38%, 34%~36%, and specifically 35%.

[0158] In this invention, the electrolyte slurry contains an electrolyte material with a mass content of 60% to 70%, 62% to 68%, or 64% to 66%, specifically 64%.

[0159] In this invention, the screen printing stencil aperture can be 280~380 mesh, 300~360 mesh, 320~340 mesh, or specifically 325 mesh.

[0160] Finally, this invention utilizes a yttrium-stabilized zirconia porous sintering plate to perform degreasing heat treatment and two sintering processes on the hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blanks obtained in the above steps to obtain a half cell, which is then used to prepare a single cell.

[0161] In this invention, the degreasing heat treatment preferably includes a rapid initial heating stage, a stepped heating stage, a high-temperature constant temperature stage, and a controlled-rate cooling stage.

[0162] In this invention, the temperature cutoff point for the rapid heating in the front section can be 80~120℃, 85~115℃, 90~110℃, 95~105℃, or specifically 100℃.

[0163] In this invention, the rapid heating time in the front section can be ≥200 min, ≥210 min, or ≥220 min.

[0164] In this invention, the heating rate of the intermediate stepped heating section can be 0.1~0.5℃ / min, 0.12~0.4℃ / min, or 0.15~0.3℃ / min. Specifically, it can be 0.1~0.2℃ / min.

[0165] In this invention, the intermediate step heating time can be ≥1080min, ≥1100min, or ≥1120min.

[0166] In this invention, the number of step points in the intermediate stepped heating can be 3 to 5, specifically 3, 4, or 5.

[0167] In this invention, the intermediate stepped heating stage has a constant temperature section at the step point before the high temperature constant temperature point. The duration of the constant temperature section can be ≥120 min, ≥130 min, or ≥140 min.

[0168] In this invention, the high-temperature constant temperature can be 220~260℃, 230~250℃, or 230~240℃, specifically 230℃.

[0169] In this invention, the high-temperature constant temperature time can be ≥240min, ≥250min, or ≥260min.

[0170] In this invention, the temperature cutoff point for controlled cooling can be 50~100℃, 70~100℃, 90~100℃, or specifically 100℃.

[0171] In this invention, the cooling time for controlled cooling can be ≥260 min, ≥270 min, or ≥280 min.

[0172] In this invention, the two sintering processes preferably include a first debinding sintering and a second tempering and pressing.

[0173] In this invention, the first degreasing sintering preferably includes segmented heating, high-temperature holding and step-down cooling.

[0174] In this invention, the segmented heating preferably includes a first heating segment, a first constant temperature segment, a second heating segment, a second constant temperature segment, a third variable speed heating segment, a third constant temperature segment, a fourth heating segment, a fourth constant temperature segment, and a fifth heating segment.

[0175] In this invention, the cutoff temperature of the first heating stage can be 230~270℃, 235~265℃, 240~260℃, 245~255℃, or specifically 250℃.

[0176] In this invention, the duration of the first heating stage can be ≥400 min, ≥450 min, or ≥500 min.

[0177] In this invention, the heat preservation time of the first constant temperature section can be ≥120min, ≥130min, or ≥140min.

[0178] In this invention, the cutoff temperature of the second heating stage can be 440~460℃, 444~456℃, 448~452℃, or specifically 450℃.

[0179] In this invention, the time of the second heating stage can be ≥200 min, ≥220 min, or ≥250 min.

[0180] In this invention, the heat preservation time of the second constant temperature section can be ≥60min, ≥70min, or ≥80min.

[0181] In this invention, the cutoff temperature of the third variable speed heating section can be 1130~1170℃, 1135~1165℃, 1140~1160℃, 1145~1155℃, or specifically 1150℃.

[0182] In this invention, the time of the third variable speed heating stage can be ≥850 min, ≥870 min, or ≥900 min.

[0183] In this invention, the heating rate of the third variable-speed heating section can be 0.2~3℃ / min, 0.5~2.5℃ / min, or 1~2℃ / min. Specifically, it can be 0.5~2.5℃ / min.

[0184] In this invention, the number of speed change points in the third speed-changing heating section can be 3 to 5, specifically 3, 4, or 5.

[0185] In this invention, the heat preservation time of the third constant temperature section can be ≥120min, ≥130min, or ≥140min.

[0186] In this invention, the cutoff temperature of the fourth heating stage can be 1230~1270℃, 1235~1265℃, 1240~1260℃, 1245~1255℃, or specifically 1250℃.

[0187] In this invention, the time of the fourth heating stage can be ≥400 min, ≥450 min, or ≥500 min.

[0188] In this invention, the heat preservation time of the fourth constant temperature section can be ≥120min, ≥130min, or ≥140min.

[0189] In this invention, the time of the fifth heating stage can be ≥560 min, ≥580 min, or ≥600 min.

[0190] In this invention, the high-temperature insulation temperature can be 1370~1410℃, 1375~1405℃, 1380~1400℃, 1385~1395℃, or specifically 1390℃.

[0191] In this invention, the high-temperature heat preservation time can be ≥240min, ≥250min, or ≥260min.

[0192] In this invention, the cutoff temperature of the first step of the stepped cooling can be 1080~1120℃, 1085~1115℃, 1090~1110℃, or 1095~1110℃, specifically 1100℃.

[0193] In this invention, the first step cooling time can be ≥200 min, ≥220 min, or ≥250 min.

[0194] In this invention, the holding time of the first step of the stepped cooling at the cutoff temperature can be ≥120 min, ≥130 min, or ≥140 min.

[0195] In this invention, the cutoff temperature of the second step of the stepped cooling can be 680~720℃, 685~715℃, 690~705℃, or 695~700℃, specifically 700℃.

[0196] In this invention, the second step cooling time can be ≥200 min, ≥220 min, or ≥250 min.

[0197] In this invention, after the cutoff temperature of the second step, the stepped cooling is preferably followed by natural cooling.

[0198] In this invention, the second tempering and pressing preferably includes segmented heating, high-temperature holding and variable-speed cooling;

[0199] In this invention, the segmented heating preferably includes a first heating segment, a first constant temperature segment, and a second heating segment;

[0200] In this invention, the cutoff temperature of the first heating stage can be 980~1020℃, 985~1015℃, 990~1010℃, 995~1005℃, or specifically 1000℃.

[0201] In this invention, the time of the first heating stage can be ≥475 min, ≥480 min, or ≥485 min.

[0202] In this invention, the heat preservation time of the first constant temperature section can be ≥60min, ≥70min, or ≥80min.

[0203] In this invention, the time of the second heating stage can be ≥360min, ≥370min, or ≥380min.

[0204] In this invention, the high-temperature insulation temperature can be 1340~1380℃, 1345~1375℃, 1350~1370℃, 1355~1365℃, and specifically 1360℃.

[0205] In this invention, the high-temperature heat preservation time can be ≥300min, ≥320min, or ≥350min.

[0206] In this invention, the temperature cutoff point of the variable speed cooling can be 680~720℃, 685~715℃, 690~710℃, 695~705℃, or specifically 700℃.

[0207] In this invention, the cooling rate of the variable speed cooling can be 1~4℃ / min, 1.5~3.5℃ / min, or 2~3℃ / min.

[0208] In this invention, the cooling time of the variable speed cooling can be ≥280min, ≥290min, or ≥300min.

[0209] In this invention, the number of speed change points for variable speed cooling can be 1 to 2, either 1 or 2.

[0210] In this invention, the preparation process in step 4) preferably includes the following steps:

[0211] Configure the barrier layer slurry and the oxygen electrode layer slurry;

[0212] The barrier layer paste is screen-printed onto the electrolyte layer preform of the half-cell, and sintered to obtain the barrier layer preform. Then, the oxygen electrode layer paste is screen-printed onto the barrier layer preform, and sintered again to obtain the single cell.

[0213] The preparation method provided by this invention, through precise optimization of slurry formulation, multi-stage ball milling and defoaming processes, coating and drying control, and adaptive sintering process design, yields SOEC single-cell solar cells. The preparation method of the support pre-powder provided by this invention includes: the ratio range of nickel oxide, YSZ, and graphite powder; ball milling parameters (speed, time, solvent dosage); drying and sieving processes; formulation and preparation process of each functional layer slurry: powder and solvent ratios for the hydrogen electrode functional layer, electrolyte layer, barrier layer, and oxygen electrode layer; component matching of terpineol solvent; specific parameters for planetary ball milling; coating and forming process: combined parameters of casting blade height, casting speed, number of printing repetitions, and drying environment (temperature, humidity, time); multi-stage sintering process: debinding temperature curve; temperature control strategy for primary sintering (heating rate, holding temperature and time at each stage), secondary tempering and pressing; and sintering parameters for the barrier layer and oxygen electrode layer. The complete preparation process provided by this invention is a combined process from pre-powder to support, sequential printing of each functional layer, and sintering, including the parameter matching relationship of each step.

[0214] This invention enhances the structural integrity of the support structure: by optimizing the slurry formulation and ball milling and defoaming processes, porosity and microcracks within the support are eliminated, enhancing mechanical strength and airtightness, and preventing breakage and gas leakage. It ensures the uniformity of cell performance: uniform slurry dispersion and precise coating thickness result in balanced distribution of electrode active materials, consistent conductivity and catalytic activity across different regions, and improved electrolysis performance stability. It strengthens interlayer bonding and structural stability: adapting to the sintering shrinkage characteristics of each functional layer, and releasing thermal stress through customized sintering curves, it reduces defects such as warpage and interlayer delamination, extending battery life. Furthermore, it is suitable for large-scale production: simplifying step-by-step operation processes improves process stability and repeatability, increases yield, and meets the batch supply requirements of SOEC systems for large-size cells.

[0215] This invention aims to complete and refine the overall technical solution, ensuring the composition and structure of the hydrogen electrode support and SOEC single-cell solar cell, and further improving the electrochemical performance of the hydrogen electrode and SOEC single-cell solar cell. The application of the aforementioned hydrogen electrode support in the preparation of SOEC single-cell solar cells and a method for preparing large-size SOEC single-cell solar cells specifically include the following:

[0216] Nickel oxide and yttrium oxide-stabilized zirconium oxide (8YSZ) were mixed in a mass ratio of 4:6-6:4, a certain amount of pore-forming agent was added, and anhydrous ethanol was added. The mixture was ball-milled at 300 rpm for 12 hours and then dried to obtain anode support powder.

[0217] Furthermore, the pore-forming agent is 1200-mesh graphite powder, added at a mass ratio of 2% to 5% of the nickel oxide and yttrium oxide-stabilized zirconium oxide (8YSZ) mixture.

[0218] Take the above-mentioned NiO-8YSZ mixture, add binder and anhydrous ethanol, and mill at 200 rpm for 24 hours; then add binder and plasticizer, and continue ball milling at 250 rpm for 24 hours, with a ball-to-material ratio of 10:1.

[0219] The adhesive is polyvinyl butyral (PVB) or PVP; the plasticizer is polyethylene glycol PEG400 or dibutyl phthalate.

[0220] The ball-milled slurry was filtered through a sieve to separate the grinding balls and the slurry. The slurry was then placed in a vacuum environment of approximately 0.8 MPa for about 30 minutes to remove bubbles. The resulting slurry was then cast into a film, with the height of the casting head and the casting speed controlled. It was then dried at 30°C and atmospheric pressure for 1 day before use.

[0221] Configuring hydrogen electrode functional layer slurry and electrolyte slurry

[0222] Under magnetic stirring, solvents for the hydrogen electrode functional layer and electrolyte screen printing pastes were prepared using terpineol, ethyl cellulose, binder, and plasticizer. Screened YSZ powder and nickel oxide were selected to prepare the electrolyte layer and functional material layer screen printing pastes. Powder and solvent were weighed according to a specific solid content ratio, calculated, and poured into a ball mill jar. The mixture was then planetarily rotated and ball-milled for 12 hours. Afterward, it was removed and placed in a beaker for vacuum degassing, ready for screen printing.

[0223] Under a humidity condition of 40%, the hydrogen electrode functional layer was screen-printed on the above-mentioned hydrogen electrode support, repeated twice, and then dried for 24 hours. On this basis, the YSZ electrolyte layer was printed, repeated twice, and then dried for 24 hours.

[0224] The hydrogen electrode support / hydrogen electrode functional layer / electrolyte green body with uniform size is obtained by cutting with a cutter, and debinding and co-sintering are carried out using a porous yttrium oxide-stabilized zirconia sintering plate.

[0225] After sintering, the battery cells are removed and subjected to a second firing using a yttrium oxide-stabilized zirconia support plate.

[0226] After sintering, a barrier layer and oxygen electrode paste are screen-printed onto the half-cell. The paste preparation...

[0227] Under magnetic stirring conditions, a barrier layer slurry and an oxygen electrode functional layer were prepared using terpineol, ethyl cellulose, binder, and plasticizer. Sieve-processed GDC powder and LSCF-GDC powder were selected to prepare the slurry. The powder and solvent were weighed according to a specific solid content ratio, calculated, and then poured into a ball mill jar. The jar was planetarily rotated and ball-milled for 12 hours. Afterward, the slurry was placed in a beaker for vacuum degassing, ready for screen printing.

[0228] After printing the barrier layer, sintering is performed. After sintering, the oxygen electrode functional layer is printed, and then sintered again.

[0229] The present invention provides the application of a hydrogen electrode support in the preparation of SOEC single-cell solar cells and a method for preparing SOEC single-cell solar cells. The present invention specifically designs a hydrogen electrode support with a specific structure and composition for use in the preparation of SOEC single-cell solar cells. This invention also provides a stable method for preparing large-size single-cell solar cells. Firstly, it optimizes the support preparation process and slurry formulation, improving the structural integrity of the support, eliminating internal pores and microcracks, enhancing the mechanical strength and airtightness of the solar cell, and preventing breakage or gas leakage during operation. Secondly, it improves the coating process of the electrode and electrolyte layers and the slurry dispersion, achieving precise control of the thickness of each functional layer on the large-size substrate, promoting uniform dispersion of active materials, ensuring consistency in conductivity and catalytic activity in different areas of the solar cell, and improving the overall electrolytic performance stability. Thirdly, it adapts the organic carrier composition and sintering shrinkage characteristics of each functional layer, optimizing thermal processing parameters to release thermal stress, reducing interfacial defects such as delamination and warping, strengthening the bonding strength between functional layers, and extending battery life. This invention improves process stability and repeatability, increases yield, and meets the mass supply requirements of large-size solar cells for SOEC system industrialization.

[0230] The SOEC single-cell solar cell prepared by this invention improves the structural integrity of the support: by optimizing the slurry formulation and ball milling and defoaming processes, porosity and microcracks within the support are eliminated, enhancing mechanical strength and airtightness, and preventing breakage and gas leakage. It ensures the uniformity of cell performance: uniform slurry dispersion and precise coating thickness result in balanced distribution of electrode active materials, consistent conductivity and catalytic activity across regions, and improved electrolytic performance stability. It strengthens interlayer bonding and structural stability: adapting to the sintering shrinkage characteristics of each functional layer, and releasing thermal stress through customized sintering curves, it reduces defects such as warpage and interlayer delamination, extending cell lifespan. Furthermore, it is suitable for large-scale production: simplifying step-by-step operation processes improves process stability and repeatability, increases yield, and meets the batch supply requirements of SOEC systems for large-size solar cells.

[0231] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, illustrates the application of the hydrogen electrode support provided by the present invention in the preparation of SOEC single-cell solar cells and a method for preparing SOEC single-cell solar cells. However, it should be understood that these embodiments are implemented under the premise of the technical solution of the present invention, and provide detailed implementation methods and specific operating procedures. They are only for further illustrating the features and advantages of the present invention, and are not intended to limit the scope of the claims of the present invention. The scope of protection of the present invention is not limited to the following embodiments.

[0232] Example 1

[0233] Weigh 240g of 3YSZ and 360g of nickel oxide, and physically mix them at a mass ratio of 4:6. Add 22g of graphite powder (passed through a 1200-mesh sieve) and 270mL of anhydrous ethanol as a solvent. Run the mixture in a planetary ball mill at 200rpm for 10 hours. Afterward, remove the mixture, dry it at 60℃, pass it through a 150-mesh sieve, and store the dried powder as a pre-cast powder for later use. The operation process is as follows: Figure 1 As shown.

[0234] See Figure 1 , Figure 1 A schematic diagram of the processing flow for the hydrogen electrode support pre-powder provided by the present invention.

[0235] A 1L nylon grinding jar and agate grinding beads (80 10mm beads and 300 6mm beads) were selected as the grinding container. 530g of the pre-mixed powder was weighed, and polyvinylpyrrolidone (PVP) binder was added. The mixture was then placed in a planetary ball mill at 200 rpm for 6 hours. The grinding jar was removed, and polyvinyl butyral (PVB) binder was added. The milling speed was adjusted to 250 rpm, and milling continued for 18 hours. The grinding jar was then removed again, and polyethylene glycol (PEG400) plasticizer and dibutyl phthalate were added. Milling continued at 250 rpm for 15 hours. The slurry was then sieved into a large beaker, and the grinding beads were filtered out. A casting process was then performed with a cutter height of 2mm and a casting speed of 1cm / s. The mixture was dried at 30℃ and low humidity for 2 days. The hydrogen electrode support was then cut, following the procedure described below. Figure 2 As shown.

[0236] See Figure 2 , Figure 2 A simplified schematic diagram illustrating the process flow for preparing and casting the hydrogen electrode support casting slurry provided by this invention.

[0237] terpineol solvent

[0238] Terpineol solvent was prepared under magnetic stirring at 500 rpm for 2 hours. Then, 96 g of terpineol, 2 g of ethyl cellulose, 2 g of polyvinyl butyral binder, and 2 g of dibutyl phthalate plasticizer were added sequentially. 8YSZ powder was weighed into a crucible, pre-fired at 600℃ for 2 hours, sieved through a 150-mesh sieve, and dispensed.

[0239] Preparation and fabrication of NiO / 8YSZ hydrogen electrode functional layer:

[0240] A 100mL polytetrafluoroethylene (PTFE) ball mill jar was selected as the milling container. Zirconia grinding beads (30 10mm beads and 80 6mm beads) were chosen. Terpineol solvent comprised 30% of the total mass, and YSZ and NiO each comprised 35%. A planetary rotary ball mill was used for grinding at 300rpm for 12 hours. The slurry was then sieved and vacuum degassed. Screen printing was performed on the aforementioned hydrogen electrode support green body using a 325-mesh screen. After printing, the material was dried at room temperature for one day. The operation was as follows. Figure 3 As shown.

[0241] See Figure 3 , Figure 3 A simplified schematic diagram illustrating the preparation and printing process of the hydrogen electrode functional layer paste provided by this invention.

[0242] Preparation and processing of 8YSZ electrolyte layer:

[0243] A 100mL polytetrafluoroethylene (PTFE) ball mill jar was selected as the milling container. Zirconia grinding beads (30 10mm beads and 80 6mm beads) were chosen. Terpineol solvent comprised 36% of the total mass, and YSZ comprised 64%. A planetary rotary ball mill was used for grinding at 300rpm for 12 hours. The slurry was then sieved and vacuum degassed. Screen printing was then performed on the aforementioned hydrogen electrode functional layer preform using a 325-mesh screen. The operation was as follows: Figure 4 As shown.

[0244] See Figure 4 , Figure 4 A simplified schematic diagram illustrating the preparation and printing process of the electrolyte layer slurry provided by this invention.

[0245] Sintering of hydrogen electrode support / hydrogen electrode functional layer / electrolyte:

[0246] The debinding operation is performed using a high-temperature furnace with exhaust ventilation; the heating curve is as follows: Figure 5 As shown, the initial heating phase involves a rapid increase in temperature from room temperature to around 100℃; the phased heating phase involves gradually increasing the temperature to 120℃, 150℃, 180℃, and finally 230℃; the cooling phase involves cooling from 230℃ to 100℃ and then allowing it to cool naturally.

[0247] The overall process follows a debinding and sintering rhythm of "gradual heating + high-temperature holding + gradual cooling," which is suitable for the debinding and sintering requirements of components such as hydrogen electrode supports.

[0248] See Figure 5 , Figure 5 The adhesive removal temperature curve of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention.

[0249] Primary sintering of hydrogen electrode support / hydrogen electrode functional layer / electrolyte:

[0250] The solar cells are sintered using a muffle furnace, and the temperature rise curve is as follows: Figure 6 As shown, a process of "segmented heating + high-temperature holding + stepped cooling" is adopted to meet the densification requirements during solar cell sintering. In this invention, the co-sintering process of SOEC hydrogen electrode / electrolyte adopts a multi-stage temperature control curve, as follows: Heating stage: Starting from room temperature (0℃), the temperature is gradually increased to 250℃ over 400 minutes, and held for 120 minutes; the temperature is further increased for 200 minutes to 450℃, and held for 60 minutes; subsequently, the temperature is increased sequentially for 100 minutes to 700℃, 450 minutes to 1000℃, 300 minutes to 1150℃ followed by a 120-minute hold, 400 minutes to 1250℃ followed by a 120-minute hold, and 560 minutes to 1390℃. The temperature is held at the highest sintering temperature of 1390℃ for 240 minutes to achieve sufficient densification and interfacial bonding between the hydrogen electrode support and the electrolyte. Cooling stage: The temperature is reduced from 1390℃ to 1100℃ for 200 minutes and held for 120 minutes; then cooled to 700℃ for another 200 minutes and then allowed to cool naturally to room temperature to complete the sintering process.

[0251] See Figure 6 , Figure 6 The first sintering temperature curve of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention.

[0252] Because the hydrogen electrode support, functional layer, and electrolyte have different material shrinkage characteristics, the degree of shrinkage of each layer is mismatched during the first sintering, which generates internal stress and ultimately leads to the curling and deformation of the battery cell. This invention uses a secondary tempering and pressing method to flatten the cell. By reheating to a high temperature and applying a certain external pressure, the plasticity of the material at high temperature is utilized to flatten the curled battery cell again, further relieving the interlayer internal stress.

[0253] Secondary sintering and leveling of hydrogen electrode support / hydrogen electrode functional layer / electrolyte:

[0254] The solar cells are sintered using a muffle furnace, and the temperature rise curve is as follows: Figure 7 As shown, the temperature rise curve of the secondary tempering and flattening adopts a temperature control strategy of "segmented heating - high temperature holding - step cooling". The specific process is as follows: segmented heating stage: the temperature rises from room temperature at a slow rate for 475 minutes to 1000℃, and holds for 60 minutes; then the temperature continues to rise for 360 minutes to 1360℃. In this stage, the cell gradually reaches the plastic temperature range through step heating, while avoiding rapid heating that will cause new thermal stress.

[0255] High-temperature insulation stage: Insulation at 1360℃ for 300 minutes. This temperature matches the high-temperature plasticity of the material. Combined with external pressure, it can effectively flatten the curled battery cells and promote the release of interlayer internal stress.

[0256] The stepped cooling stage involves cooling from 1360℃ to 1000℃ over 180 minutes, followed by another 100 minutes to 700℃. This slow, stepped cooling further alleviates residual thermal stress and ensures the structural stability of the flattened solar cells. This temperature rise curve design utilizes the high-temperature plasticity of the material to achieve cell flattening while controlling the temperature to avoid secondary damage and reduce the risk of re-curling, thus meeting the process requirements of SOEC cell tempering and pressing.

[0257] See Figure 7 , Figure 7 The secondary sintering and tempering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte provided by the present invention are shown.

[0258] Preparation and processing of GDC barrier layer slurry:

[0259] The smooth-surfaced solar cell obtained by the above sintering process is then printed with a barrier layer, such as... Figure 8 As shown, a 100mL polytetrafluoroethylene ball mill jar was selected as the milling container. Zirconia grinding beads (30 10mm beads and 80 6mm beads) were chosen. Terpineol solvent accounted for 40% of the total mass, and dried GDC accounted for 60%. A planetary rotary ball mill was used for milling at 300rpm for 12 hours. The slurry was sieved and vacuum defoamed. Screen printing was then performed on the electrolyte preform using a 325-mesh screen to obtain the hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer. The operation is as follows. Figure 8 As shown.

[0260] See Figure 8 , Figure 8 A simplified schematic diagram illustrating the preparation and printing process of the barrier layer paste provided by this invention.

[0261] Sintering of the GDC barrier layer:

[0262] The core function of the GDC barrier layer is to suppress the interdiffusion of elements between the electrode and the electrolyte. The sintering curve, through the process design of "slow heating-medium temperature holding-slow cooling", ensures the density of the barrier layer while taking into account the interfacial bonding and structural stability.

[0263] like Figure 9As shown, the sintering of the GDC barrier layer adopts a temperature control curve of "slow heating - medium-temperature holding - slow cooling". Slow heating stage: The temperature is gradually increased from room temperature to 1000℃ over 500 minutes, then further increased for 250 minutes to 1250℃. Slow heating avoids thermal stress caused by rapid heating of the GDC layer, while ensuring uniform preheating of the powder particles, laying the foundation for densification. Medium-temperature holding stage: The temperature is held at 1250℃ for 120 minutes. This temperature is within the effective sintering range of GDC, achieving both particle neck growth and moderate densification (meeting the airtightness requirements of the barrier layer) while avoiding excessive sintering that could damage the interface with the substrate. Slow cooling stage: The temperature is first reduced from 1250℃ to 1000℃ over 125 minutes, then further reduced for 150 minutes to 700℃. This stepped slow cooling alleviates residual stress caused by the difference in thermal expansion coefficients between the GDC and the substrate materials, ensuring the structural stability of the barrier layer.

[0264] See Figure 9 , Figure 9 The sintering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer provided by the present invention are shown.

[0265] Preparation and processing of LSCF-GDC oxygen electrode slurry:

[0266] An oxygen electrode layer is formed on the side of the barrier layer of the battery cell obtained by the above sintering, such as... Figure 10 As shown, a 100mL polytetrafluoroethylene ball mill jar was selected as the milling container. Zirconia grinding beads (30 10mm beads and 80 6mm beads) were chosen. Terpineol solvent accounted for 38% of the total mass, dried GDC accounted for 18%, and dried LSCF accounted for 44%. A planetary rotary ball mill was used for milling at 300rpm for 12 hours. The slurry was sieved and vacuum defoamed. Screen printing was then performed on the above-mentioned barrier layer preform. The screen printing stencil used had an aperture of 325 mesh. This yielded a hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer / oxygen electrode layer. The operation was as follows: Figure 10 As shown.

[0267] See Figure 10 , Figure 10 A simplified schematic diagram illustrating the preparation and printing process of the oxygen electrode layer paste provided by this invention.

[0268] Sintering of LSCF-GDC oxygen electrode:

[0269] The heating curve is as follows Figure 11As shown, the sintering of the LSCF-GDC oxygen electrode adopts a temperature control curve of "slow heating - medium-temperature holding - slow cooling". In the slow heating stage, the temperature is gradually increased from room temperature to 1000℃ over 500 minutes. This slow heating avoids thermal stress caused by rapid heating of the LSCF-GDC oxygen electrode layer, while ensuring uniform preheating of the powder particles. The medium-temperature holding at 1000℃ allows for initial particle growth without causing performance degradation due to excessive sintering at high temperatures. The slow cooling (1000℃ → 700℃) stepwise slow cooling further releases residual thermal stress between the layers, matches the shrinkage characteristics of each layer, reduces the risk of deformation and cracking during component cooling, and ensures the overall integrity of the multi-layer structure.

[0270] See Figure 11 , Figure 11 The sintering curves of the hydrogen electrode support / hydrogen electrode functional layer / electrolyte / barrier layer / oxygen electrode provided by the present invention.

[0271] The batteries prepared above were analyzed by scanning electron microscopy, such as... Figure 12 As shown, the multi-layer structure and microstructure from the surface to the substrate are clearly displayed. The interfaces of each layer are tightly bonded, with no obvious cracks, peeling or other defects, indicating that the sintering process effectively ensures the interlayer bonding. At the same time, the porosity differences of different layers (high porosity of the support layer / functional layer and dense electrolyte / barrier layer) respectively meet the functional requirements of "support / mass transfer" and "ion conduction / element barrier", which is in line with the structural design logic of SOEC single cell.

[0272] See Figure 12 , Figure 12 This is a scanning electron microscope image of the battery prepared according to the present invention.

[0273] According to the processing sequence:

[0274] Hydrogen electrode support layer: As the bottom substrate, it has a loose porous structure with high porosity and uniform pore distribution, which not only provides mechanical support for the battery cell, but also provides sufficient gas channels for the hydrogen electrode reaction.

[0275] Hydrogen electrode functional layer: Located above the support layer, its porosity is slightly lower than that of the support layer but still maintains its porous characteristics. The particles are uniformly packed, which can expose more catalytic active sites and adapt to the electrocatalytic reaction requirements of the hydrogen electrode.

[0276] Electrolyte layer: A continuous, dense thin layer above the functional layer, without obvious pores, ensuring efficient ion conduction while achieving sealed isolation of hydrogen and oxygen side gases;

[0277] Barrier layer: A thin transition layer between the electrolyte and the oxygen electrode. It has a dense structure and can block the interdiffusion of elements between the oxygen electrode and the electrolyte, thus preventing interfacial reactions from degrading battery performance.

[0278] Oxygen electrode layer: Located on the top layer, it has a structure that combines density and fine pores, which not only ensures the activity of electrocatalytic reaction, but also facilitates the transport of oxygen-side gas and the extraction of reaction products.

[0279] The application of the hydrogen electrode support provided by this invention in the preparation of SOEC single-cell solar cells and a method for preparing large-size SOEC single-cell solar cells have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this invention. The above descriptions of the embodiments are only for the purpose of helping to understand the method and core ideas of this invention, including the best mode, and also to enable any person skilled in the art to practice this invention, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, several improvements and modifications can be made to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the protection scope of the claims of this invention. The scope of protection of this patent is defined by the claims and may include other embodiments that can be conceived by those skilled in the art. If these other embodiments have structural elements that are not different from the textual description of the claims, or if they include equivalent structural elements that are not substantially different from the textual description of the claims, then these other embodiments should also be included within the scope of the claims.

Claims

1. Application of hydrogen electrode support in the fabrication of SOEC single-cell solar cells; The hydrogen electrode support, based on raw materials, comprises: Nickel oxide, yttrium oxide stabilized zirconium oxide, pore-forming agent graphite, binder, plasticizer and solvent; The mass ratio of nickel oxide to yttrium oxide-stabilized zirconium oxide is (5~7):(5~3); The pore-forming agent graphite comprises 2% to 5% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide.

2. The application according to claim 1, characterized in that, The adhesive comprises polyvinyl butyral and / or polyvinylpyrrolidone; The amount of the binder is 4 wt% to 10 wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide; The plasticizer includes polyethylene glycol PEG400 and / or dibutyl phthalate; The amount of plasticizer used is 4 wt% to 10 wt% of the total mass of nickel oxide and yttrium oxide-stabilized zirconium oxide; The applications include increasing the flexibility and / or ductility of the green cast strip. The applications include those that enhance the mechanical strength and / or airtightness of solar cells.

3. The application according to claim 1, characterized in that, The solvent includes anhydrous ethanol; The individual solar cells include large-size individual solar cells; The dimensions of the individual battery are 15cm*15cm; The hydrogen electrode support is prepared by a casting process; The applications include one or more of the following: improving the structural integrity of the support, eliminating internal pores in the support, and eliminating microcracks in the support.

4. A method for preparing an SOEC single-cell solar cell, characterized in that, Includes the following steps: 1) Nickel oxide, yttrium oxide-stabilized zirconium oxide, pore-forming agent graphite and solvent are mixed and ball-milled to obtain a pre-mixed powder. A binder is then added and mixed, followed by the addition of a plasticizer and ball-milling to obtain a slurry. 2) After defoaming the slurry obtained in the above steps, it is cast into a film and dried to obtain a hydrogen electrode support blank; 3) Prepare hydrogen electrode functional layer slurry and electrolyte slurry. First, screen print hydrogen electrode functional layer slurry on the hydrogen electrode support blank obtained in the above steps, then screen print electrolyte slurry, and then air dry to obtain hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blank. 4) Using a yttrium-stabilized zirconia porous sintering plate, the hydrogen electrode support / hydrogen electrode functional layer / electrolyte layer green blanks obtained in the above steps are subjected to degreasing heat treatment and two sintering processes to obtain a half cell, which is then used to prepare a single cell.

5. The preparation method according to claim 4, characterized in that, The mass ratio of nickel oxide to yttrium oxide-stabilized zirconium oxide is (5~7):(5~3); The particle size of the pore-forming agent graphite is 800~1500 mesh; In the preparation of the pre-mixed powder, the ratio of the volume of the solvent to the total mass of nickel oxide and yttrium-stabilized zirconium oxide is 0.3~0.8 mL / g; The mixing and ball milling time is 8~24 hours; The rotation speed of the mixing ball mill is 100~400 rpm.

6. The preparation method according to claim 4, characterized in that, The molar content of yttrium oxide in the yttrium-stabilized zirconium oxide is 3%~8%; The ball milling time is 24~48 hours; The ball mill rotates at a speed of 200-300 rpm; The height of the casting cutter head in the casting process is 2~3mm; The casting speed is 0.5~2cm / s.

7. The preparation method according to claim 4, characterized in that, The hydrogen electrode functional layer slurry includes terpineol composite solvent and hydrogen electrode material; The electrolyte slurry includes terpineol composite solvent and electrolyte material; The terpineol composite solvent includes terpineol solvent, ethyl cellulose, binder, and plasticizer; The hydrogen electrode material includes nickel oxide and yttrium oxide-stabilized zirconium oxide; The electrolyte material includes yttrium-stabilized zirconium oxide.

8. The preparation method according to claim 7, characterized in that, The mass content of nickel oxide in the hydrogen electrode functional layer slurry is 30%~40%; In the hydrogen electrode functional layer slurry, the mass content of yttrium oxide-stabilized zirconium oxide is 30%~40%; In the electrolyte slurry, the mass content of the electrolyte material is 60%~70%; The screen printing stencil has an aperture of 280-380 mesh. The degreasing heat treatment includes a rapid heating stage, a stepped heating stage, a high-temperature constant temperature stage, and a controlled-rate cooling stage. The temperature cutoff point for the rapid heating in the front section is 80~120℃; The rapid heating time in the front section is ≥200 min; The heating rate of the intermediate stepped heating section is 0.1~0.5℃ / min; The intermediate-section stepped heating time is ≥1080 min; The number of step points in the intermediate stage of stepped heating is 3 to 5; The intermediate stepped heating stage has a constant temperature section at the step point before the high temperature constant temperature point, and the constant temperature section lasts for ≥120 minutes. The temperature for the high-temperature constant temperature is 220~260℃; The time for maintaining the high temperature is ≥240 min; The temperature cutoff point for the controlled-speed cooling is 50~100℃; The cooling time for the controlled-speed cooling is ≥260 min.

9. The preparation method according to claim 8, characterized in that, The two sintering processes include a first degreasing sintering and a second tempering and pressing. The first degreasing sintering includes segmented heating, high-temperature holding and stepped cooling; The segmented heating includes a first heating segment, a first constant temperature segment, a second heating segment, a second constant temperature segment, a third variable speed heating segment, a third constant temperature segment, a fourth heating segment, a fourth constant temperature segment, and a fifth heating segment; The cutoff temperature of the first heating stage is 230~270℃; The duration of the first heating stage is ≥400 min; The heat preservation time of the first constant temperature section is ≥120 min; The cutoff temperature of the second heating stage is 440~460℃; The duration of the second heating stage is ≥200 min; The heat preservation time of the second constant temperature section is ≥60min; The cutoff temperature of the third variable-speed heating section is 1130~1170℃; The duration of the third variable-speed heating stage is ≥850 min; The heating rate of the third variable-speed heating section is 0.2~3℃ / min; The number of speed change points in the third variable speed heating section is 3 to 5; The heat preservation time of the third constant temperature section is ≥120 min; The cutoff temperature of the fourth heating stage is 1230~1270℃; The duration of the fourth heating stage is ≥400 min; The heat preservation time of the fourth constant temperature section is ≥120 min; The duration of the fifth heating stage is ≥560 min; The high-temperature insulation temperature is 1370~1410℃; The high-temperature insulation time is ≥240 min; The cutoff temperature for the first step of the stepped cooling is 1080~1120℃; The first step of the stepped cooling process takes ≥200 min. The first step of the stepped cooling process maintains a constant temperature at the cutoff temperature for ≥120 min. The cutoff temperature for the second step of the stepped cooling is 680~720℃; The second step of the stepped cooling process takes ≥200 min. The stepped cooling process proceeds naturally after the cutoff temperature of the second step.

10. The preparation method according to claim 9, characterized in that, The second tempering and pressing includes staged heating, high-temperature holding and variable-speed cooling; The segmented heating includes a first heating segment, a first constant temperature segment, and a second heating segment; The cutoff temperature of the first heating stage is 980~1020℃; The duration of the first heating stage is ≥475 min; The heat preservation time of the first constant temperature section is ≥60min; The duration of the second heating stage is ≥360 min; The high-temperature insulation temperature is 1340~1380℃; The high-temperature insulation time is ≥300 min; The temperature cutoff point for the variable-speed cooling is 680~720℃; The cooling rate of the variable-speed cooling is 1~4℃ / min; The cooling time for the variable speed cooling is ≥280 min; The variable speed cooling has 1 to 2 speed change points; The preparation process in step 4) includes the following steps: Configure the barrier layer slurry and the oxygen electrode layer slurry; The barrier layer paste is screen-printed onto the electrolyte layer preform of the half-cell, and sintered to obtain the barrier layer preform. Then, the oxygen electrode layer paste is screen-printed onto the barrier layer preform, and sintered again to obtain the single cell.

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