Solid oxide electrolysis cell and method for its production by joule heating rapid sintering and use thereof

Abstract

This invention relates to the field of solid oxide electrolytic cells, and more particularly to a solid oxide electrolytic cell and a method for preparing it by Joule heating rapid sintering, as well as its application. Preparation method: S1: A composite cathode functional layer slurry is formed by mixing cathode powder and 5-20 wt.% Li₂CO₃ with an organic binder solution; cathode powder and anode powder are then mixed with the organic binder solution to form cathode slurry and anode slurry, respectively; S2: The cathode functional layer is first coated on one side of the electrolyte, followed by the cathode slurry; the anode slurry is then coated on the other side of the electrolyte, and the mixture is dried to obtain a full cell preform; S3: The full cell preform is subjected to flash Joule heat treatment. The preparation method of this invention can improve electrode catalytic performance, expand the three-phase reaction interface, accelerate ion transport rate at the interface, and enhance the long-term working stability of the battery under high-temperature conditions. The prepared electrolytic cell has high uniformity, strong applicability to electrode materials, and is easy to scale up.

Description

Technical Field

[0001] This invention relates to the field of solid oxide electrolytic cells, and in particular to a solid oxide electrolytic cell and a method for preparing it by Joule heating rapid sintering, as well as their applications. Background Technology

[0002] Solid oxide electrolysis cells (SOECs) are clean and efficient electrochemical energy conversion devices capable of electrolyzing carbon dioxide and water into syngas or hydrogen under high-temperature conditions, and they hold significant application potential in renewable energy storage and carbon resource recycling. However, the performance and stability of SOECs largely depend on the quality of the interfacial structure between the electrolyte and the electrodes.

[0003] In traditional preparation processes, SOEC typically requires prolonged sintering at 1000-1200 °C for several hours to form a stable electrode-electrolyte interface structure. This high-temperature, long-duration sintering not only consumes a lot of energy but also easily leads to severe coarsening of electrode grains, reducing the electrode's specific surface area and thus weakening its electrochemical reactivity. Furthermore, due to the difference in thermal expansion coefficients between the electrolyte and electrode materials, interfacial stress is easily generated during high-temperature sintering and subsequent thermal cycling, resulting in poor interfacial contact or even delamination, reducing ion transport efficiency and significantly shortening the battery's lifespan under high-temperature electrolysis conditions. Therefore, developing a novel preparation method that enables rapid sintering, promotes tight bonding at the cathode-electrolyte interface, and thus obtains a firmly bonded SOEC while maintaining the porous structure of the electrode, is of significant scientific importance for improving its electrolytic performance. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings of the prior art by proposing a method for preparing solid oxides using an electrolytic cell and Joule heating rapid sintering, and its application.

[0005] The first objective of this invention is to provide a method for preparing a Joule heating rapid sintering solid oxide electrolytic cell, comprising the following steps: S1: The cathode powder and 5-20 wt.% Li2CO3 are mixed evenly with an organic binder solution to form a composite cathode functional layer slurry; the cathode powder and anode powder are mixed evenly with an organic binder solution to form cathode slurry and anode slurry; S2: Using screen printing, a composite cathode functional layer paste is first coated on one side of the electrolyte, followed by the cathode paste; the anode paste is then coated on the other side of the electrolyte, and after drying, a full cell preform is obtained. S3: The solid oxide electrolytic cell is obtained by flash evaporation Joule heat treatment of the full cell preform under an inert atmosphere, a low oxygen partial pressure atmosphere, or a vacuum atmosphere.

[0006] Furthermore, the flash Joule heat treatment involves sintering at 900-1100 °C for 10-40 s with a heating rate of 100-150 Ks. -1 The current for heat treatment is 200-500 A.

[0007] Furthermore, the inert atmosphere is argon or nitrogen; the low oxygen partial pressure atmosphere is a protective atmosphere with an oxygen volume fraction of no more than 1%.

[0008] Furthermore, the cathode powder is a perovskite oxide with the following structural formula: ABO 3-δ Where A = one or more of La, Sr, Ca, Ba, Ce, Pr, Nd, Sm, and Gd, and B = one or more of Fe, Cr, and Mo, and 0 < δ < 3.

[0009] Furthermore, the anode powder is a perovskite oxide; the electrolyte is an oxygen ion conductor.

[0010] Furthermore, the perovskite oxide is Pr 1-x-y Ba x Sr y Co z Fe 1-z O 6-δ La x Sr 1-x One of the CoFeO3.

[0011] Furthermore, the oxygen ion conductor is La. x Sr 1-x Ga y Mg 1-y O 3-δ Y2O3-ZrO2, Sm x Gd 1-x O 1.95 Ce x Gd 1- x O 1.95 One of them.

[0012] Furthermore, the binder is terpineol containing 7.5-10.0 wt.% ethyl cellulose; the mass ratio of the cathode powder or anode powder to the binder is 1:1.

[0013] A second objective of this invention is to provide a solid oxide electrolytic cell prepared using the above-described preparation method.

[0014] A third objective of the present invention is to provide an application of the solid oxide fuel electrolyzer as described above for CO2 electrolysis, H2O electrolysis, or CO2-H2O co-electrolysis.

[0015] This invention utilizes flash Joule heat treatment to complete high-temperature sintering within tens of seconds, significantly shortening the battery manufacturing cycle and effectively suppressing electrode / electrolyte interface delamination or even detachment caused by traditional long-duration high-temperature sintering. Simultaneously, this rapid non-equilibrium sintering process inhibits grain coarsening of the electrode material, reduces particle size, and induces the formation of abundant oxygen vacancies within the electrode material, resulting in a porous electrode structure with fine, uniformly distributed grains and rich oxygen defects. This enhances the battery's catalytic activity and carbon dioxide reduction reaction kinetics.

[0016] Joule heating rapid sintering enables the Li2CO3 functional layer to form a low-melting-point liquid phase with good wetting properties under instantaneous high temperature conditions. As a liquid phase sintering aid at the interface, it promotes interfacial wetting, particle rearrangement and ion diffusion between the cathode and electrolyte, thereby reducing the sintering temperature and accelerating the sintering kinetics, enhancing the interfacial bonding strength between the cathode and electrolyte and the high-temperature mechanical stability of the structure.

[0017] Therefore, the novel preparation method of the present invention, which achieves rapid densification of the electrode-electrolyte interface in a very short time while maintaining the porous structure of the electrode, can improve the catalytic performance of the electrode, expand the three-phase reaction interface, accelerate the ion transport rate at the interface, and enhance the long-term working stability of the battery under high temperature conditions.

[0018] The present invention has the following beneficial effects: 1. Compared with conventional battery manufacturing processes, the Joule thermal rapid sintering process used in this invention can complete high-temperature sintering within tens of seconds. This process is simple, has a short sintering time, and high manufacturing efficiency. 2. The liquid-phase sintering aid formed by the Li2CO3 functional layer of the lithium carbonate interface-assisted Joule thermal rapid sintering electrolytic cell prepared in this invention at instantaneous high temperature can effectively promote interface wetting and ion diffusion, and improve the interfacial bonding strength and ion transport efficiency between the cathode and the electrolyte. 3. The SOEC electrode layer prepared by this invention has small and uniform grain size, larger active surface area, more active sites, and forms abundant oxygen vacancies during the thermodynamic unsteady process of rapid sintering, which improves the catalytic performance of the electrode material and the kinetics of CO2 reduction reaction. The prepared SOEC exhibits higher current density, lower polarization impedance and better long-term stability in high-temperature CO2 or H2O electrolysis. Attached Figure Description

[0019] Figure 1The La-type lithium carbonate with added Li2CO3 as a functional layer (FL) prepared by lithium carbonate interface-assisted Joule heating rapid sintering in Example 1. 0.5 Sr 0.5 La prepared by long-term sintering of FeO3 powder (abbreviated as JH-FL-LSF) in a conventional muffle furnace 0.5 Sr 0.5 XRD pattern of FeO3 powder (abbreviated as FL-LSF); Figure 2 This is a magnified cross-sectional SEM image of the cathode-electrolyte interface region of the JH-FL-LSF electrolytic cell prepared by Joule heating rapid sintering assisted by lithium carbonate interface in Example 1. Figure 3a and Figure 3b The images show SEM images comparing the cathode and electrolyte interface morphology of the JH-FL-LSF electrolytic cell prepared by rapid Joule heating with lithium carbonate interface assistance in Example 1 and the FL-LSF electrolytic cell prepared by long-term sintering in a conventional muffle furnace. Figure 4 The JH-FL-LSF electrolytic cell cathode powder prepared by lithium carbonate interface-assisted Joule heating rapid sintering in Example 1 and the FL-LSF electrolytic cell cathode powder prepared by conventional muffle furnace long-time sintering are compared. s XPS spectra comparison.

[0020] Figure 5a Current-voltage diagrams of direct CO2 electrolysis at different temperatures for SOEC with JH-FL-LSF as cathode, prepared by lithium carbonate interface-assisted Joule thermal rapid sintering in Example 1. Figure 5b This is a current-voltage diagram of the FL-LSF electrolytic cell prepared by long-term sintering in a conventional muffle furnace in Example 1 for direct electrolysis of CO2 at different temperatures; Figure 6a EIS curves of the JH-FL-LSF electrolyzer prepared by lithium carbonate interface-assisted Joule thermal rapid sintering in Example 1 at different temperatures. Figure 6b EIS curves of the full cell at different temperatures for FL-LSF electrolyzers prepared by long-term sintering in a conventional muffle furnace in Example 1; Figure 7 DRT analysis of the EIS curves of the JH-FL-LSF and FL-LSF electrolyzers in this embodiment at 1.3 V and 800 °C; Figure 8 The stability test results of the electrolytic current density of the JH-FL-LSF and FL-LSF electrolytic cells in this embodiment 1 at 800 °C and 1.3 V; Figure 9 The stability test results of the polarization resistance of the JH-FL-LSF and FL-LSF electrolytic cells in this embodiment 1 at 800 °C and 1.3 V; Figure 10 The image shows a cross-sectional SEM image of the JH-FL-LSF electrolytic cell prepared by flash evaporation and Joule heating in Example 1 after long-term stability testing. Detailed Implementation

[0021] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0022] Example 1: According to the chemical formula La 0.5 Sr 0.5 FeO 3-δ Sr(CH3COO)2, Fe(NO3)2·9H2O, and La(NO3)3·6H2O were weighed out according to stoichiometric ratio and dissolved sequentially in 100 mL of deionized water. The solution was continuously stirred magnetically at room temperature to form a homogeneous and clear mixed salt solution. Citric acid and ethylenediaminetetraacetic acid (EDTA) were added as complexing agents, and the molar ratio of total metal ions to citric acid to EDTA was controlled at 1:1:1.5. Subsequently, ammonia was added dropwise to adjust the pH of the solution to 7-8, resulting in a clear, transparent, and stable precursor solution. The precursor solution was transferred to an evaporating dish and placed in a constant temperature water bath at 80 °C for 10 h to obtain a gel-like substance.

[0023] The obtained gel-like material was calcined in an electronic universal furnace at a temperature of approximately 200-300 °C to obtain a black, fluffy intermediate product, which was then thoroughly ground to obtain a black powder. The black powder was placed in a muffle furnace and annealed at a rate of 3 °C / min to 600 °C for 2 h in a static air atmosphere to remove residual carbon and organic matter, yielding a precursor powder. The precursor powder was then heated to 1000 °C at a rate of 3 °C / min and annealed for 5 h to obtain the LSF cathode material.

[0024] The LSF cathode material and the binder (the mass ratio of terpineol and ethyl cellulose is 92:8) are mixed evenly at a mass ratio of 1:1 to prepare a cathode paste; PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ Anode slurry is prepared by thoroughly mixing anode powder and binder at a mass ratio of 1:1. The cathode powder and 10 wt.% Li2CO3 were mixed evenly with the binder to form a composite slurry; LSGM (La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O3) electrolyte powder was dry-pressed and sintered in air at 1450℃ for 5 h to obtain a dense LSGM electrolyte support with a thickness of about 160 µm.

[0025] One layer of the composite slurry and two layers of the cathode slurry are sequentially coated on one side of the electrolyte, and three layers of the anode slurry are coated on the other side to obtain an unsintered full cell preform.

[0026] The prepared unsintered full-cell preform was placed in a molybdenum boat within a flash Joule thermal synthesis apparatus. The cavity was then evacuated and argon gas was introduced. This process was repeated three times. No additional gas was introduced during the entire heating process, and the entire process was completed in static argon gas with no gas flow. The temperature was monitored in real time by detecting the infrared radiation energy emitted from the object's surface. The calcination temperature was adjusted by controlling the applied current. The set parameters were: temperature 1000 °C, current 300 A, holding time 30 s, and heating rate 100-150 K / s. -1 After rapid sintering at 1000 ℃, a flash Joule heating rapid prototyping solid oxide electrolytic cell (JH-FL-LSF) based on Li2CO3 was prepared.

[0027] A thin layer of conductive silver paste was coated on the electrode surface for current collection. The entire cell was then encapsulated, leaving the anode continuously exposed to air. The effective area of ​​the anode was 0.28 cm². 2 The cathode side of the full cell was first purged with nitrogen at 800 °C to remove air, then activated with CO2 for 2 h, before SOEC electrolysis testing was performed.

[0028] Comparative Example 1 Solid oxide electrolytic cell for FL-LSF cathode prepared by long-term sintering in a conventional muffle furnace According to the chemical formula La 0.5 Sr 0.5 FeO 3-δSr(CH3COO)2, Fe(NO3)2·9H2O, and La(NO3)3·6H2O were weighed out according to stoichiometric ratio and dissolved sequentially in 100 mL of deionized water. The solution was continuously stirred magnetically at room temperature to form a homogeneous and clear mixed salt solution. Citric acid and ethylenediaminetetraacetic acid (EDTA) were added as complexing agents, and the molar ratio of total metal ions to citric acid to EDTA was controlled at 1:1:1.5. Subsequently, ammonia was added dropwise to adjust the pH of the solution to 7-8, resulting in a clear, transparent, and stable precursor solution. The precursor solution was transferred to an evaporating dish and placed in a constant temperature water bath at 80 °C for 10 h to obtain a gel-like substance.

[0029] The obtained gel-like material was calcined in an electronic universal furnace at a temperature of approximately 200-300 °C to obtain a black, fluffy intermediate product, which was then thoroughly ground to obtain a black powder. The black powder was placed in a muffle furnace and annealed at a rate of 3 °C / min to 600 °C for 2 h in a static air atmosphere to remove residual carbon and organic matter, yielding a precursor powder. The precursor powder was then heated to 1000 °C at a rate of 3 °C / min and annealed for 5 h to obtain the LSF cathode material.

[0030] The LSF cathode material and the binder (the mass ratio of terpineol and ethyl cellulose is 92:8) are mixed evenly at a mass ratio of 1:1 to prepare a cathode paste; PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ Anode slurry is prepared by thoroughly mixing anode powder and binder at a mass ratio of 1:1. The cathode powder and 10 wt.% Li2CO3 were mixed evenly with the binder to form a composite slurry; La 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O3 (LSGM) electrolyte powder was dry-pressed and sintered in air at 1450 °C for 5 h to obtain a dense LSGM electrolyte support with a thickness of approximately 160 µm.

[0031] One layer of the composite slurry and two layers of the cathode slurry are sequentially coated on one side of the electrolyte, and three layers of the anode slurry are coated on the other side to obtain an unsintered full cell preform.

[0032] The unsintered full cell preform was calcined in a conventional muffle furnace at 1000 °C for 5 h to obtain a conventional shaped solid oxide electrolytic cell (FL-LSF) assisted by Li2CO3.

[0033] A thin layer of conductive silver paste was coated on the electrode surface for current collection. The entire cell was then encapsulated, leaving the anode continuously exposed to air. The effective area of ​​the anode was 0.28 cm². 2 The cathode side of the full cell was first purged with nitrogen at 800 °C to remove air, then activated with CO2 for 2 h, before SOEC electrolysis testing was performed.

[0034] See appendix Figure 1 The figures show the XRD patterns of JH-FL-LSF powder prepared by rapid Joule heating with lithium carbonate interface assistance in Example 1 and FL-LSF powder prepared by conventional long-term sintering in a muffle furnace in Comparative Example 1. Analysis reveals that Li2CO3 diffraction peaks are still observed in the sample powder prepared by flash Joule heating, indicating that Li2CO3 did not completely volatilize during the rapid heating and cooling process. Instead, it remained in a liquid phase at the electrolyte and cathode interface underwent interfacial wetting and ion diffusion, thereby enhancing the interfacial bonding between the two phases, facilitating ion transport, and improving the battery structural stability. In contrast, no obvious Li2CO3 diffraction peaks were observed in the sample powder prepared by long-term sintering in a conventional muffle furnace, indicating that a large amount of Li2CO3 had volatilized during the long-term sintering process, accompanied by the formation of other impurity phases.

[0035] See appendix Figure 2 The image shown is a magnified cross-sectional SEM image of the cathode-electrolyte interface region of the JH-FL-LSF electrolytic cell prepared by Joule thermal rapid sintering with lithium carbonate interface assistance in Example 1. It can be observed that ion interdiffusion occurs between the electrolyte and the cathode, confirming that at the instantaneous high temperature of Joule thermal rapid sintering, liquid-phase Li2CO3 does indeed undergo interfacial wetting and ion diffusion at the cathode-electrolyte interface, thereby making the two-phase interface more tightly bonded.

[0036] See appendix Figure 3a and attached Figure 3bThe images show a comparison of the cathode-electrolyte interface morphology between the JH-FL-LSF electrolytic cell prepared by rapid Joule heating with lithium carbonate interface assistance in Example 1 and the FL-LSF electrolytic cell prepared by long-term sintering in a conventional muffle furnace. The images clearly show that the JH-FL-LSF cathode and electrolyte interface are tightly bonded with no obvious gaps, and the cathode particles are smaller and more uniformly distributed. In contrast, the FL-LSF cathode and electrolyte interface shows obvious gaps, and the cathode powder exhibits agglomeration. This comparison further demonstrates that the JH-FL-LSF electrolytic cell prepared by rapid Joule heating with lithium carbonate interface assistance has better interfacial structural stability, which is beneficial for expanding the three-phase interface and accelerating ion transport.

[0037] See appendix Figure 4 To compare the O 1s XPS spectra of the JH-FL-LSF electrolytic cell cathode powder prepared by rapid Joule heating with lithium carbonate interface assistance in Example 1 and the FL-LSF electrolytic cell cathode powder prepared by long-term sintering in a conventional muffle furnace, the fine XPS spectrum of O 1s was fitted, yielding four characteristic peaks, corresponding to lattice oxygen (O) 2- ), highly reactive oxygen species (O2) 2- / O - ), surface adsorbed oxygen (OH) - / CO3 2- The surface adsorbed oxygen and surface adsorbed water molecules (H2O) are significantly increased in JH-FL-LSF cathode powder. The ratio of adsorbed oxygen to lattice oxygen increases from 0.95 in FL-LSF to 1.23 in Joule-heated rapid-burning JH-FL-LSF, directly reflecting the increased oxygen vacancy concentration. Simultaneously, its lattice oxygen content is also significantly increased. 2- The shift towards lower binding energy indicates that JH-FL-LSF cathode powder is more prone to forming oxygen vacancies. The resulting cathode powder, rich in oxygen vacancies and with fine and uniformly distributed grains, is more conducive to improving the catalytic performance of the battery, thereby accelerating the CO2 reduction reaction kinetics.

[0038] See appendix Figure 5a and 5b The figures show the current-voltage diagrams for the direct electrolysis of CO2 using the JH-FL-LSF and FL-LSF electrolytic cells in Example 1 at different temperatures. The figures show that the electrolysis current density increases with increasing temperature; and at the same temperature, the current density of JH-FL-LSF is higher than that of FL-LSF. Under operating conditions of 800 °C and 1.5 V, the current density of JH-FL-LSF reaches 3.31 A cm⁻¹. -2 It is FL-LSF (1.59 A cm). -2The CO2 reduction performance of JH-FL-LSF is 2.08 times that of the standard CO2 reduction material. This indicates that JH-FL-LSF has superior CO2 reduction performance. The tight bonding interface between the cathode and electrolyte, achieved through interface optimization and Joule heating rapid sintering, effectively promotes the kinetics of CO2 reduction. Furthermore, the higher defect concentration and smaller, more uniform particle size of the cathode material are also key factors in improving catalytic performance.

[0039] See appendix Figure 6a and 6b The figures show the EIS curves of the JH-FL-LSF electrolytic cell and the FL-LSF electrolytic cell used as SOEC cathodes in Example 1 at different temperatures. As shown in the figure, the polarization resistance of both JH-FL-LSF and FL-LSF decreases with increasing temperature, and the polarization resistance of JH-FL-LSF is consistently lower than that of FL-LSF. At 1.3 V and 800 °C, the polarization resistance of JH-FL-LSF is only 0.06 Ω cm. 2 Compared to FL-LSF (0.18 Ω cm), 2 The concentration of ions was reduced by 66.67%. This further verifies that the tight bonding between the cathode and the electrolyte interface is beneficial to improving the ion transport rate, thereby significantly improving the electrochemical performance of the battery.

[0040] Figure 7 DRT analysis of the EIS curves of JH-FL-LSF and FL-LSF electrolyzers at 1.3 V and 800 °C in Example 1 is presented. To elucidate the underlying mechanism, relaxation time distribution (DRT) analysis was performed on the EIS data, which deconvolves three different electrochemical processes: a high-frequency region (HF) related to oxygen ion transport at the electrode-electrolyte interface; a mid-frequency region (MF) reflecting charge transfer and electrochemical reduction of CO2; and a low-frequency region (LF) representing CO2 adsorption and CO desorption processes. At 800 °C and 1.3 V, the peak areas of HF, MF, and LF all decreased to varying degrees, confirming that the Joule thermal rapid sintering electrolyzer based on the lithium carbonate interface reduces charge transfer impedance, enhances ion diffusion, and accelerates CO2 adsorption and CO desorption, thereby significantly accelerating CO2RR kinetics.

[0041] See appendix Figure 8 and Figure 9The results of stability tests (current density, polarization resistance) for the JH-FL-LSF and FL-LSF electrolyzers in Example 1 at 800 °C and an electrolysis voltage of 1.3 V are shown. Long-term operational stability is crucial for practical SOEC applications. After approximately 270 h of durability testing, the current density of the JH-FL-LSF cell did not show significant degradation, and the polarization resistance did not change significantly. However, after approximately 230 h of durability testing, the current density of the FL-LSF cell showed significant degradation, and the polarization resistance increased significantly. This indicates that the JH-FL-LSF exhibits superior electrochemical stability.

[0042] See appendix Figure 10 The image shows a cross-sectional SEM image of the JH-FL-LSF electrolyzer prepared by lithium carbonate-assisted flash Joule heating rapid sintering in Example 1 after a long-term stability test. After 270 h of testing, the electrolyte is still very dense with a thickness of about 160 µm. The electrode and electrolyte interface are tightly bonded with no obvious signs of delamination or separation, indicating that the electrolyzer prepared by lithium carbonate-assisted flash Joule heating rapid sintering has excellent long-term stability at high temperatures. Example 2: According to the chemical formula La 0.5 Sr 0.5 FeO 3-δ Sr(CH3COO)2, Fe(NO3)2·9H2O, and La(NO3)3·6H2O were weighed out according to stoichiometric ratio and dissolved in 100 mL of deionized water. The solution was continuously stirred magnetically at room temperature to form a homogeneous and clear mixed salt solution. Citric acid and ethylenediaminetetraacetic acid (EDTA) were added as complexing agents, and the molar ratio of total metal ions to citric acid to EDTA was controlled at 1:1:1.5. Subsequently, ammonia was added dropwise to adjust the pH of the solution to 7-8, resulting in a clear, transparent, and stable precursor solution. The precursor solution was transferred to an evaporating dish and placed in a constant temperature water bath at 80 °C for 10 h to obtain a gel-like substance. The obtained gel-like substance was calcined in an electric multi-purpose furnace at approximately 200-300 °C to obtain a black, fluffy intermediate product, which was then thoroughly ground to obtain a black powder. The black powder was placed in a muffle furnace and heated to 600 °C at a heating rate of 3 °C / min under static air atmosphere, and annealed for 2 h to remove residual carbon and organic matter from the material, obtaining precursor powder. The precursor powder was then heated to 1000 °C at a heating rate of 3 °C / min and annealed for 5 h to obtain LSF cathode material.

[0043] LSF cathode material and binder (terpineol and ethyl cellulose in a mass ratio of 92:8) were mixed uniformly at a mass ratio of 1:1 to prepare cathode paste. PrBa 0.5 Sr0.5 Co 1.5 Fe 0.5 O 5+δ Anode powder and binder are thoroughly mixed at a mass ratio of 1:1 to prepare anode slurry. Cathode powder and 10 wt.% Li2CO3 are mixed evenly with binder to form composite slurry.

[0044] Y 0.08 Zr 0.92 O 2-δ (YSZ) electrolyte powder is dry-pressed and sintered in air at 1450 °C for 5 h to obtain a dense SDC electrolyte support. One layer of the composite slurry and two layers of the cathode slurry are sequentially coated on one side of the electrolyte, and three layers of the anode slurry are coated on the other side to obtain an unsintered full cell preform.

[0045] The prepared unsintered full-cell preform was placed in a molybdenum boat within a flash Joule thermal synthesis apparatus. The cavity was then evacuated and argon gas was introduced. This process was repeated three times. No additional gas was introduced during the entire heating process, and the entire process was completed in static argon gas with no gas flow. The temperature was monitored in real time by detecting the infrared radiation energy emitted from the object's surface. The calcination temperature was adjusted by controlling the applied current. The set parameters were: temperature 1000 °C, current 300 A, holding time 30 s, and heating rate 100-150 K / s. -1 A Joule-thermal rapid sintering solid oxide electrolytic cell based on Li2CO3 interface assistance was prepared by rapid sintering at 1000 °C. A thin layer of conductive silver paste was coated on the electrode surface for current collection. The entire cell was then encapsulated, leaving the anode continuously exposed to air. The effective area of ​​the anode was 0.28 cm². 2 The cathode side of the full cell was first purged with nitrogen at 800 °C to remove air, then activated with CO2 for 2 h, before SOEC electrolysis testing was performed.

[0046] Example 3: According to the chemical formula SrFe 0.75 Mo 0.25 O 3-δ(SFM) Sr(CH3COO)2, Fe(NO3)2·9H2O, and (NH4)2MoO4 were weighed out according to stoichiometric ratio and dissolved sequentially in 100 mL of deionized water. The solution was continuously stirred magnetically at room temperature to form a homogeneous and clear mixed salt solution. Citric acid and ethylenediaminetetraacetic acid (EDTA) were added as complexing agents, controlling the molar ratio of total metal ions, citric acid, and EDTA to be 1:1:1.5. Subsequently, ammonia was added dropwise to adjust the pH of the solution to 7-8, resulting in a clear, transparent, and stable precursor solution. The precursor solution was transferred to an evaporating dish and placed in a constant temperature water bath at 80 ℃ for 10 h to obtain a gel-like substance. The obtained gel-like substance was calcined in an electric multi-purpose furnace at approximately 200-300 ℃ to obtain a black, fluffy intermediate product, which was then thoroughly ground to obtain a black powder. The black powder was placed in a muffle furnace and heated to 600 °C at a heating rate of 3 °C / min under static air atmosphere, and annealed for 2 h to remove residual carbon and organic matter from the material, obtaining precursor powder. The precursor powder was then heated to 1000 °C at a heating rate of 3 °C / min and annealed for 5 h to obtain SFM cathode material.

[0047] SFM cathode material and binder (terpineol and ethyl cellulose in a mass ratio of 92:8) were mixed uniformly at a mass ratio of 1:1 to prepare cathode paste. PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ Anode powder and binder were thoroughly mixed at a mass ratio of 1:1 to prepare an anode slurry. Cathode powder and 10 wt.% Li₂CO₃ were mixed uniformly with the binder to form a composite slurry. LSGM electrolyte powder was dry-pressed and sintered in air at 1450 °C for 5 h to obtain a dense LSGM electrolyte support. One layer of the composite slurry and two layers of the cathode slurry were sequentially coated on one side of the electrolyte, and three layers of the anode slurry were coated on the other side to obtain an unsintered full cell preform.

[0048] The prepared unsintered full-cell preform was placed in a molybdenum boat within a flash Joule thermal synthesis apparatus. The cavity was then evacuated and argon gas was introduced. This process was repeated three times. No additional gas was introduced during the entire heating process, and the entire process was completed in static argon gas with no gas flow. The temperature was monitored in real time by detecting the infrared radiation energy emitted from the object's surface. The calcination temperature was adjusted by controlling the applied current. The set parameters were: temperature 1000 °C, current 300 A, holding time 30 s, and heating rate 100-150 K / s. -1A Li₂CO₃-assisted flash Joule heating rapid prototyping solid oxide electrolytic cell was prepared by rapid sintering at 950 °C. A thin layer of conductive silver paste was coated on the electrode surface for current collection. The entire cell was then encapsulated, leaving the anode continuously exposed to air. The effective area of ​​the anode was 0.28 cm². 2 The cathode side of the full cell was first purged with nitrogen at 800 °C to remove air, then activated with CO2 for 2 h, before SOEC electrolysis testing was performed.

[0049] For any points not covered above, existing technologies shall apply.

[0050] Although specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the direction of the invention or exceeding the scope defined by the appended claims. Those skilled in the art should understand that any modifications, equivalent substitutions, improvements, etc., made to the above embodiments based on the technical essence of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a Joule heating rapid sintering solid oxide electrolytic cell, characterized in that, Includes the following steps: S1: Mix cathode powder and 5-20 wt.% Li2CO3 of cathode powder with an organic binder solution to form a composite cathode functional layer slurry; mix cathode powder and anode powder with an organic binder solution to form cathode slurry and anode slurry; S2: Using screen printing, a composite cathode functional layer paste is first coated on one side of the electrolyte, followed by the cathode paste; the anode paste is then coated on the other side of the electrolyte, and after drying, a full cell preform is obtained. S3: The solid oxide electrolytic cell is obtained by flash evaporation Joule heat treatment of the full cell preform under an inert atmosphere, a low oxygen partial pressure atmosphere, or a vacuum atmosphere.

2. The preparation method according to claim 1, characterized in that, Flash Joule heat treatment involves sintering at 900-1100 ℃ for 10-40 s with a heating rate of 100-150 K s. -1 The current for heat treatment is 200-500 A.

3. The preparation method according to claim 1, characterized in that, The inert atmosphere is argon or nitrogen; the low oxygen partial pressure atmosphere is a protective atmosphere with an oxygen volume fraction not exceeding 1%.

4. The preparation method according to claim 1, characterized in that, The cathode powder is a perovskite oxide with the structural formula ABO. 3-δ Where A = one or more of La, Sr, Ca, Ba, Ce, Pr, Nd, Sm, and Gd, and B = one or more of Fe, Cr, and Mo, and 0 < δ < 3.

5. The preparation method according to claim 1, characterized in that, The anode powder is a perovskite oxide; the electrolyte is an oxygen ion conductor.

6. The preparation method according to claim 5, characterized in that, The perovskite oxide is Pr 1-x- y Ba x Sr y Co z Fe 1-z O 6-δ La x Sr 1-x One of the CoFeO3.

7. The preparation method according to claim 5, characterized in that, The oxygen ion conductor is La. x Sr 1-x Ga y Mg 1- y O 3-δ Y2O3-ZrO2, Sm x Gd 1-x O 1.95 Ce x Gd 1-x O 1.95 One of them.

8. The preparation method according to claim 1, characterized in that, The binder is terpineol containing 7.5-10.0 wt.% ethyl cellulose; the mass ratio of the cathode powder or anode powder to the binder is 1:

1.

9. A solid oxide electrolytic cell prepared by the preparation method according to any one of claims 1-8.

10. An application of the solid oxide fuel electrolyzer as described in claim 9, characterized in that: It can be used for CO2 electrolysis, H2O electrolysis, or CO2-H2O co-electrolysis.

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