Nano-structure composite oxygen electrode material and preparation method thereof

Abstract

The invention relates to a nano-structure composite oxygen electrode material and a preparation method thereof, and belongs to the technical field of solid oxide electrolytic cells. The material is xSmBa < 0.5 > Sr < 0.5 > Co2O < 5.5 >-(100-x) Sm < 0.2 > Ce < 0.8 > O < 1.9, 0 lt >, xlt; 100, 100; wherein SmBa0. 5Sr0. 5Co2O5.5 is used as an electronic conductor and a catalytic active phase, Sm0. 2Ce0. 8O1.9 is used as an ionic conductor phase, and the two phases form a three-dimensional interpenetrating and uniformly-distributed composite structure under the nanoscale. The nano composite electrode material prepared by the invention forms continuously interlaced electron-ion dual channels, effectively improves interface transmission kinetics, greatly increases the three-phase interface density, and provides a reliable material basis for industrial application of a solid oxide electrolysis technology.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide electrolytic cell technology, and relates to a nanostructured composite oxygen electrode material and its preparation method. Background Technology

[0002] Solid oxide fuel cells and their reversible systems (solid oxide electrolyzers) have shown great potential, particularly in the electrolysis of water to produce hydrogen using renewable electricity, due to their high efficiency and wide fuel adaptability. An ideal oxygen electrode material needs to possess high catalytic activity at intermediate temperatures, excellent electron-ion mixed conductivity, and good compatibility with electrolytes (such as Sm...). 0.2 Ce 0.8 O 1.9 The coefficient of thermal expansion (SCD) is matched to that of the double perovskite material SmBaCo2O. 5.5 SBCO exhibits excellent electrochemical performance, but its excessively high coefficient of thermal expansion is a fatal flaw. A traditional improvement strategy involves physically mixing SBCO with SDC to prepare a composite electrode, leveraging the low thermal expansion of SDC for harmonization. However, this mechanical mixing method suffers from inherent microstructural defects: firstly, achieving a uniform nanoscale distribution of the two phases is difficult, resulting in poor interfacial contact between the electronic conductor (SBCO) and the ionic conductor (SDC), hindering the construction of a highly efficient and synergistic conductive network; secondly, the non-uniform mixing severely limits the three-phase interfacial density required for the electrochemical reaction, leading to a significant reduction in the overall catalytic activity of the electrode. Summary of the Invention

[0003] To address the problems of poor interfacial contact and insufficient catalytic activity caused by uneven physical mixing in existing composite oxygen electrode materials, this invention provides a nanostructured composite oxygen electrode material and its preparation method. This invention employs a one-step synthesis technique to directly construct xSmBa 0.5 Sr 0.5 Co2O 5.5 – (100-x) Sm 0.2 Ce 0.8 O 1.9 (xSBSC-(100-x)SDC) nanostructured composite oxygen electrode material, SmBa 0.5 Sr 0.5 Co2O 5.5 and Sm 0.2 Ce 0.8 O 1.9 The mass ratio is x:(100-x). The nanocomposite electrode material prepared by this invention forms a continuous interwoven electron-ion dual channel, effectively improving the interfacial transport kinetics and significantly increasing the three-phase interfacial density, providing a reliable material basis for the industrial application of solid oxide electrolysis technology. The technical solution of this invention is as follows: A nanostructured composite oxygen electrode material, wherein the material is xSmBa 0.5 Sr 0.5 Co2O 5.5 - (100-x)Sm 0.2 Ce 0.8 O 1.9 0 <x<100,SmBa 0.5 Sr 0.5 Co2O 5.5 and Sm 0.2 Ce 0.8 O 1.9 The mass ratio is x:(100-x); where SmBa 0.5 Sr 0.5 Co2O 5.5 As an electronic conductor and catalytically active phase, Sm 0.2 Ce 0.8 O 1.9 As ionic conductors, the two phases form a three-dimensional interpenetrating, uniformly distributed composite structure at the nanoscale.

[0004] The preparation method of the nanostructured composite oxygen electrode material specifically includes the following steps: S1, according to the target product xSmBa 0.5 Sr 0.5 Co2O 5.5 – (100-x)Sm 0.2 Ce 0.8 O 1.9 stoichiometry, 0 <x<100,SmBa 0.5 Sr 0.5 Co2O 5.5 and Sm 0.2 Ce 0.8 O 1.9 The mass ratio is x:(100-x). Weigh out the metal salts of samarium, barium, strontium, cerium and cobalt. Dissolve the above metal salts together in deionized water. Heat and stir the solution at 90°C and 200r / min using a constant temperature magnetic stirrer until the salts are completely dissolved to obtain a clear metal salt mixed solution A. S2, Weigh citric acid according to the molar ratio of the sum of metal ions to citric acid (CA) of 1:1.5, prepare an aqueous solution of citric acid, and then add it to the metal salt solution A. Stir to obtain a clear solution B. S3. Weigh ethylenediaminetetraacetic acid (EDTA) according to the molar ratio of the sum of metal ions to EDTA being 1:(1 - 1.5), prepare an aqueous solution of ethylenediaminetetraacetic acid, and then add it to Solution B. Adjust the pH to 7 - 9 using ammonia water. Stir at 90 °C and 200 r / min until it is observed that the solution changes from a transparent state to a viscous dark purple wet gel state with a large amount of bubbles generated. S4. Put the obtained colloidal substance into an oven at 250 °C for drying, then put it into a muffle furnace for high-temperature calcination, grinding, and sieving to obtain the composite oxygen electrode powder. S5. Place the composite oxygen electrode powder in a ball mill jar and add absolute ethanol for ball milling. Place the ball-milled solution in a beaker and dry it in an oven at 80 °C to obtain the nanostructured composite oxygen electrode material.

[0005] Further, in step S4, the calcination temperature in the muffle furnace is 1100 °C and the calcination time is 10 h.

[0006] Further, in step S5, the ball milling speed is 450 r / min and the ball milling time is 5 h.

[0007] The present invention also provides an application of the composite oxygen electrode material in a solid oxide battery. The steps for preparing the solid oxide battery are as follows: (1) Thoroughly ball mill and mix the nanostructured composite oxygen electrode material with a terpineol solution containing ethyl cellulose to obtain an electrode paste. (2) Coat the electrode paste obtained in step (1) on the surface of the battery and perform high-temperature treatment to obtain the solid oxide battery.

[0008] Further, in step (1), the mass ratio of the composite oxygen electrode material powder to the terpineol containing 10 wt.% ethyl cellulose is 1:1.2, the rotation speed of the ball mill is 300 r / min, and the ball milling time is 5 h.

[0009] Further, in step (2), the temperature of the high-temperature treatment is 1100 °C and the heat preservation time is 2 h.

[0010] The present invention has the following beneficial effects compared with the prior art: The nanostructured composite oxygen electrode material xSmBa 0.5 Sr 0.5 Co2O 5.5 - (100 - x) Sm 0.2 Ce 0.8 O 1.9 , 0 < x < 100, realizes the distribution of the electron-conducting phase and the ion-conducting phase at the nanoscale, forming a three-dimensional interpenetrating network structure. Compared with the SBSC / SDC composite oxygen electrode prepared by the traditional physical mixing method used in the comparative example, the xSmBa prepared by the present invention0.5 Sr 0.5 Co2O 5.5 - (100-x) Sm 0.2 Ce 0.8 O 1.9 The nanocomposite oxygen electrode exhibits significantly superior electrochemical performance at 800℃, with a maximum power density increase of approximately 45% and a polarization impedance reduction of up to 60%. Simultaneously, it ensures excellent thermal expansion matching, enabling the battery to demonstrate outstanding structural stability during thermal cycling tests, laying the foundation for the commercial application of mid-temperature solid oxide fuel cells. Attached Figure Description

[0011] Figure 1 The images show the XRD patterns of the nanostructured composite oxygen electrode material powders obtained in Examples 1, 2, and 3. Figure 2 The polarization resistance of the symmetrical cell with nanocomposite oxygen electrode material in Example 1 under air; Figure 3 The image shows the IVP curve of a single cell using the nanostructured composite oxygen electrode material from Example 1. Detailed Implementation

[0012] The technical solution of the present invention will be described in detail below through specific embodiments. It should be understood that the following specific embodiments are merely exemplary, and any modifications or changes that do not depart from the technical solution design of the present invention should be within the scope of protection of the claims of the present invention. The present invention will be described in detail below with reference to embodiments.

[0013] <Example 1> The preparation of 90SBSC-10SDC powder includes the following steps: Step S1 is performed according to the target product 90SmBa 0.5 Sr 0.5 Co2O 5.5 - 10Sm 0.2 Ce 0.8 O 1.9 (90:10, mass ratio) To achieve the desired stoichiometric ratio, weigh out 0.2036 mol of samarium nitrate (Sm(NO3)3), 0.096 mol of barium chloride (BaCl2), 0.096 mol of strontium chloride (SrCl2), 0.046 mol of cerium nitrate (Ce(NO3)3), and 0.384 mol of cobalt nitrate (Co(NO3)2), making the mass ratio of SBSC to SDC 90:10. Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution at 90°C and 200 r / min using a constant-temperature magnetic stirrer until the salts are completely dissolved, obtaining a clear mixed metal salt solution A.

[0014] Step S2: Based on the molar ratio of citric acid (CA) to metal ions of 1.5:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, then add it to the metal nitrate solution A, and stir to obtain a clear solution B.

[0015] In step S3, based on the molar ratio of ethylenediaminetetraacetic acid (EDTA) to metal ions of 1.5:1, weigh out the EDTA, add it to a beaker containing 100 ml of deionized water, stir thoroughly with a glass rod until completely dissolved and clear, and then add it to the metal nitrate solution B.

[0016] In step S4, ammonia water is slowly added to solution B to control the pH value at around 7. The solution is stirred and heated using a constant temperature magnetic stirrer at 90°C and 200 rpm until it can be observed that the solution changes from a transparent state to a viscous dark purple wet gel state with the generation of a large number of bubbles.

[0017] In step S5, the mouth of the beaker containing the wet gel-like substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250 °C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined in a muffle furnace at 1100 °C for 10 hours. The resulting powder is then ground in a mortar and sieved through a standard test sieve to obtain composite oxygen electrode powder.

[0018] In step S6, to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added. The solid content is 50 wt.%, and further ball milling is performed. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0019] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining nanostructured composite oxygen electrode material powder with finer particle size. Figure 1 The XRD pattern of the 90SBSC-10SDC nanostructured composite oxygen electrode material powder is shown. All diffraction peaks correspond to SBSC and SDC, and no impurity phases are observed.

[0020] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.2. The ball mill speed is 300 r / min and the ball milling time is 5 h. The obtained slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested. Figure 2 The polarization resistance of the 90SBSC-10SDC composite oxygen electrode material in a symmetrical cell at 800-550℃ is shown; for example, the polarization resistance of the electrode at 750℃ is only 0.02 Ωcm. 2A lower resistance indicates that the material has better catalytic activity. Meanwhile... Figure 3 This refers to the electrochemical performance of the 90SBSC-10SDC in full-cell mode, with a peak power density exceeding 2Wcm³. -2 This indicates that the battery has high electrochemical performance.

[0021] <Example 2> The preparation of 80SBSC-20SDC powder includes the following steps: Similar to step 1 in Example 1, the process is carried out according to the target product 80SmBa. 0.5 Sr 0.5 Co2O 5.5 -20Sm 0.2 Ce 0.8 O 1.9 (80:20, mass ratio) To ensure the stoichiometric ratio, accurately weigh the corresponding amounts of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), cerium nitrate (Ce(NO3)3), and cobalt nitrate (Co(NO3)2) to achieve a mass ratio of 80:20 for SBSC and SDC. Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution at 90°C and 200 r / min using a constant-temperature magnetic stirrer until the salts are completely dissolved, yielding a clear mixed metal salt solution A.

[0022] Step S2: Based on the molar ratio of citric acid (CA) to metal ions of 1.5:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, then add it to the metal nitrate solution A, and stir to obtain a clear solution B.

[0023] Step S3: Weigh out EDTA according to the molar ratio of EDTA to metal ions of 1:1, then add it to a beaker containing 100ml of deionized water, stir thoroughly with a glass rod until completely dissolved and clear, then add it to metal nitrate solution B.

[0024] In step S4, ammonia water is slowly added to solution B to control the pH value at around 7. The solution is stirred and heated using a constant temperature magnetic stirrer at 90°C and 200 rpm until it can be observed that the solution changes from a transparent state to a viscous dark purple wet gel state with the generation of a large number of bubbles.

[0025] In step S5, the mouth of the beaker containing the wet gel-like substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined in a muffle furnace at 1100°C for 10 hours. The resulting powder is then ground in a mortar and sieved through a standard test sieve to obtain composite oxygen electrode powder. Figure 1 The image shows the XRD pattern of the 80SBSC-20SDC composite oxygen electrode in Example 2.

[0026] Step S6: In order to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added. The solid content is 50%, and further ball milling is performed. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0027] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining nanostructured composite oxygen electrode material powder. Figure 1 The XRD pattern of the 80SBSC-20SDC composite oxygen electrode powder is shown. All diffraction peaks correspond to SBSC and SDC, and no impurity phases are observed.

[0028] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.2. The ball mill speed is 300 r / min and the ball milling time is 5 h. The obtained slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0029] <Example 3> The preparation of 60SBSC-40SDC powder includes the following steps: Similar to step 1 in Example 1, the process is carried out according to the target product 60SmBa. 0.5 Sr 0.5 Co2O 5.5 -40Sm 0.2 Ce 0.8 O 1.9 (60:40, mass ratio) To ensure the stoichiometric ratio, accurately weigh the corresponding amounts of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), cerium nitrate (Ce(NO3)3), and cobalt nitrate (Co(NO3)2) to achieve a mass ratio of SBSC to SDC of 60:40. Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution at 90°C and 200 r / min using a constant-temperature magnetic stirrer until the salts are completely dissolved, yielding a clear mixed metal salt solution A.

[0030] Step S2: Based on the molar ratio of citric acid (CA) to metal ions of 1.5:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, then add it to the metal salt solution A, and stir to obtain a clear solution B.

[0031] Step S3: Weigh out EDTA according to the molar ratio of EDTA to metal ions of 1:1, then add it to a beaker containing 100ml of deionized water, stir thoroughly with a glass rod until completely dissolved and clear, then add it to metal nitrate solution B.

[0032] In step S4, slowly add ammonia water to solution B, controlling the pH value to around 7. Heat the solution using a constant-temperature magnetic stirrer at 90°C and 200 rpm until the solution changes from a transparent state to a viscous, dark purple wet gel state, accompanied by the generation of numerous bubbles.

[0033] In step S5, the mouth of the beaker containing the wet gel-like substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined in a muffle furnace at 1100°C for 10 hours. The resulting powder is then ground in a mortar and sieved through a standard test sieve to obtain composite oxygen electrode powder. Figure 1 The image shows the XRD pattern of the 80SBSC-20SDC composite oxygen electrode in Example 3.

[0034] In step S6, to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added (just enough to cover the powder) for further ball milling. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0035] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining nanostructured composite oxygen electrode material powder with finer particle size. Figure 1 The XRD pattern of the 60SBSC-40SDC composite oxygen electrode powder shows that all diffraction peaks correspond to SBSC and SDC, and no impurity phases are observed.

[0036] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.2. The ball mill speed is 300 r / min and the ball milling time is 5 h. The obtained slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0037] <Example 4> The preparation of 40SBSC-60SDC powder includes the following steps: Similar to step 1 in Example 1, the process is carried out according to the target product 40SmBa. 0.5 Sr 0.5 Co2O 5.5 -60Sm 0.2 Ce 0.8 O 1.9 (40:60, mass ratio) To ensure the stoichiometric ratio, accurately weigh the corresponding amounts of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), cerium nitrate (Ce(NO3)3), and cobalt nitrate (Co(NO3)2) to achieve a mass ratio of SBSC to SDC of 40:60. Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution at 90°C and 200 r / min using a constant-temperature magnetic stirrer until the salts are completely dissolved, yielding a clear mixed metal salt solution A.

[0038] Step S2: Based on the citric acid (CA) to metal ion molar ratio of 1:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, then add it to the metal nitrate solution A, and stir to obtain a clear solution B.

[0039] Step S3: Weigh out EDTA according to the molar ratio of EDTA to metal ions of 1:1, then add it to a beaker containing 100ml of deionized water, stir thoroughly with a glass rod until completely dissolved and clear, then add it to metal nitrate solution B.

[0040] In step S4, ammonia water is slowly added to solution B to control the pH value at around 7. The solution is stirred and heated using a constant temperature magnetic stirrer at 90°C and 200 rpm until it can be observed that the solution changes from a transparent state to a viscous dark purple wet gel state with the generation of a large number of bubbles.

[0041] In step S5, the mouth of the beaker containing the wet gel-like substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined in a muffle furnace at 1100°C for 10 hours. The resulting powder is then ground in a mortar and sieved through a standard test sieve to obtain composite oxygen electrode powder.

[0042] In step S6, to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added (just enough to cover the powder) for further ball milling. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0043] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining finely ground oxygen electrode powder with a finer particle size.

[0044] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.2. The ball mill speed is 300 r / min and the ball milling time is 5 h. The obtained slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0045] <Example 5> The preparation of 20SBSC-80SDC powder includes the following steps: Similar to step 1 in Example 1, the process is carried out according to the target product 20SmBa. 0.5 Sr 0.5 Co2O 5.5 -80Sm 0.2 Ce 0.8 O 1.9 (20:80, mass ratio) To ensure the stoichiometric ratio, accurately weigh the corresponding amounts of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), cerium nitrate (Ce(NO3)3), and cobalt nitrate (Co(NO3)2) to achieve a mass ratio of SBSC to SDC of 20:80. Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution using a constant-temperature magnetic stirrer until the salts are completely dissolved, yielding a clear mixed solution of metal salts.

[0046] Step S2: Based on the molar ratio of citric acid (CA) to metal ions of 2:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, and then add it to the metal nitrate solution.

[0047] In step S3, based on the molar ratio of ethylenediaminetetraacetic acid (EDTA) to metal ions of 1:1, the weighed EDTA is added to a beaker containing 100 ml of deionized water. After stirring thoroughly with a glass rod until completely dissolved and clear, it is added to the metal nitrate solution.

[0048] In step S4, slowly add ammonia to the solution, controlling the pH value to around 7. Stir and heat the solution using a thermostatic magnetic stirrer until the solution changes from a transparent state to a viscous, dark purple wet gel state, accompanied by the generation of numerous bubbles.

[0049] In step S5, the mouth of the beaker containing the adhesive material is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined at high temperature in a muffle furnace. The resulting powder is ground in a mortar and sieved through a standard test sieve to obtain electrode powder.

[0050] In step S6, to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added (just enough to cover the powder) for further ball milling. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0051] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining finely ground oxygen electrode powder with a finer particle size.

[0052] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.2. The resulting slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0053] <Comparative Example 1> SBSC powder preparation includes the following steps: Similar to step 1 in Example 1, the process is carried out according to the target product SmBa. 0.5 Sr 0.5 Co2O 5.5 According to the stoichiometric ratio, accurately weigh the corresponding amounts of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), and cobalt nitrate (Co(NO3)2). Dissolve the above metal salt precursors together in 500 ml of deionized water. Heat the solution using a constant-temperature magnetic stirrer until the salts are completely dissolved, obtaining a clear mixed solution of metal salts.

[0054] Step S2: Based on the molar ratio of citric acid (CA) to metal ions of 1.5:1, calculate the required mass of CA and weigh it. Add CA to a beaker containing 100 ml of deionized water, stir until completely dissolved, and then add it to the metal nitrate solution.

[0055] In step S3, based on the molar ratio of ethylenediaminetetraacetic acid (EDTA) to metal ions of 1.5:1, the weighed EDTA is added to a beaker containing 100 ml of deionized water, and stirred thoroughly with a glass rod until completely dissolved and clear. Then, it is added to the metal nitrate solution.

[0056] In step S4, slowly add ammonia to the solution, controlling the pH value at 7. Stir and heat the solution using a thermostatic magnetic stirrer until the solution changes from a transparent state to a viscous, dark purple wet gel state, accompanied by the generation of numerous bubbles.

[0057] In step S5, the mouth of the beaker containing the gelatinous substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined at high temperature in a muffle furnace. The resulting powder is ground in a mortar and sieved through a standard test sieve to obtain electrode powder.

[0058] Step S6: In order to obtain oxygen electrode powder with finer particle size, the sieved electrode powder is placed in a ball mill jar and anhydrous ethanol is added. The solid content is 50%, and further ball milling is performed. The ball milling speed is 450 r / min and the ball milling time is 5 h.

[0059] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining oxygen electrode powder with a finer particle size. Figure 3 The XRD pattern of the SBSC oxygen electrode powder shows that all diffraction peaks correspond to SBSC, and no impurity phases are observed.

[0060] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.5. The resulting slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0061] <Comparative Example 2> The preparation of SBSC60 / SDC40 powder includes the following steps: Step S1 is performed according to the target product SmBa 0.5 Sr 0.5 Co2O 5.5 According to the stoichiometric ratio, accurately weigh the corresponding masses of samarium nitrate (Sm(NO3)3), barium nitrate (Ba(NO3)2), strontium nitrate (Sr(NO3)2), and cobalt nitrate (Co(NO3)2). Dissolve the above metal salt precursors together in 500 ml of deionized water, and heat the solution using a constant temperature magnetic stirrer until the salts are completely dissolved, obtaining a clear mixed solution of metal salts.

[0062] Step S2: Based on the molar ratio of ethylenediaminetetraacetic acid (EDTA):citric acid (CA):metal ions of 1:1.5:1, calculate and weigh the required mass of CA and EDTA. Add CA to a beaker containing 100 ml of deionized water and stir until completely dissolved.

[0063] Step S3: Slowly add the CA solution to the metal nitrate solution. Weigh the EDTA and add it to a beaker containing 100 ml of deionized water. Add an appropriate amount of ammonia and stir thoroughly with a glass rod until completely dissolved and clear. Then add the EDTA solution to the metal nitrate solution.

[0064] In step S4, slowly add ammonia to the solution, controlling the pH value to around 7. Stir and heat the solution using a thermostatic magnetic stirrer until the solution changes from a transparent state to a viscous, dark purple wet gel state, accompanied by the generation of numerous bubbles.

[0065] In step S5, the mouth of the beaker containing the gelatinous substance is covered with tin foil, leaving a vent hole, and then placed in an oven at 250°C for 10 hours to obtain honeycomb-like powder. The initial powder is then calcined at high temperature in a muffle furnace. The resulting powder is ground in a mortar and sieved through a standard test sieve to obtain electrode powder.

[0066] Step S6 will use the target product SmBa 0.5 Sr 0.5 Co2O 5.5 Sm prepared by FuelCell Materials 0.2 Ce 0.8 O 1.9 The materials were precisely weighed at a ratio of 60:40 (wt.%) and placed into a ball mill jar. Anhydrous ethanol was added, and the solid content was 50%. Further ball milling was performed by running the ball mill jar at 300 rpm for 5 hours to ensure thorough mixing. After ball milling, the mixture was thoroughly dried in a forced-air drying oven, ground in a quartz mortar, and sieved (100 mesh) to obtain the target composite oxygen electrode material.

[0067] In step S7, the ball-milled solution is placed in a beaker and placed in an oven at 80°C for 10 hours to ensure that the alcohol is completely dried, thus obtaining finely ground oxygen electrode powder with a finer particle size.

[0068] Step S8: The obtained powder is ball-milled with a terpineol solution containing 10 wt.% ethyl cellulose at a mass ratio of 1:1.5. The resulting slurry is then coated onto the surface of the SDC electrolyte, and the performance of symmetric cells and full cells is tested.

[0069] The performance tests of Examples 1-4, Comparative Examples 1 and 2 are shown in Table 1: Table 1 ; In Example 1, the polarization resistance and peak power density of the battery are 0.02 Ωcm. 2 @750℃ and 2.02Wcm -2@800℃. The polarization resistance of the 90SBSC-10SDC composite electrode at 550-800℃ is 0.01, 0.02, 0.04, 0.08, 0.3 and 1.2 Ωcm, respectively. 2 In all embodiments, the polarization resistance of the nanocomposite oxygen electrode materials synthesized using the one-step method was lower than that of pure SBSC in Comparative Example 1 and the simply mixed and ball-milled SBSC60 / SDC40 in Comparative Example 2, indicating that the nanocomposite oxygen electrode materials in the embodiments have higher electrocatalytic activity, and the peak power density of the battery in fuel cell mode is also higher than that in the comparative examples.

[0070] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A nanostructured composite oxygen electrode material, characterized in that, The material is xSmBa 0.5 Sr 0.5 Co2O 5.5 - (100-x) Sm 0.2 Ce 0.8 O 1.9 0 <x<100,SmBa 0.5 Sr 0.5 Co2O 5.5 and Sm 0.2 Ce 0.8 O 1.9 The mass ratio is x:(100-x); where SmBa 0.5 Sr 0.5 Co2O 5.5 As an electronic conductor and catalytically active phase, Sm 0.2 Ce 0.8 O 1.9 As ionic conductors, the two phases form a three-dimensional interpenetrating, uniformly distributed composite structure at the nanoscale.

2. The preparation method of the nanostructured composite oxygen electrode material as described in claim 1 specifically includes the following steps: S1, according to the target product xSmBa 0.5 Sr 0.5 Co2O 5.5 – (100-x)Sm 0.2 Ce 0.8 O 1.9 stoichiometry, 0 <x<100,SmBa 0.5 Sr 0.5 Co2O 5.5 and Sm 0.2 Ce 0.8 O 1.9 The mass ratio is x:(100-x). Weigh out the metal salts of samarium, barium, strontium, cerium and cobalt. Dissolve the above metal salts together in deionized water. Heat and stir the solution at 90°C and 200r / min using a constant temperature magnetic stirrer until the salts are completely dissolved to obtain a clear metal salt mixed solution A. S2, Weigh citric acid according to the molar ratio of the sum of metal ions to citric acid (CA) of 1:1.5, prepare an aqueous solution of citric acid, and then add it to the metal salt solution A. Stir to obtain a clear solution B. S3. Weigh EDTA at a molar ratio of 1:(1-1.5) of the sum of metal ions to EDTA, prepare an EDTA aqueous solution, and then add it to solution B. Adjust the pH to 7-9 using ammonia. Stir at 90℃ and 200r / min until the solution changes from transparent to a viscous dark purple wet gel with a large number of bubbles. S4. The obtained gel-like substance is placed in a 250℃ oven for drying, then placed in a muffle furnace for high-temperature calcination, grinding and sieving to obtain composite oxygen electrode powder. S5. The composite oxygen electrode powder was placed in a ball mill jar and anhydrous ethanol was added for ball milling. The ball-milled solution was placed in a beaker and dried in an oven at 80°C to obtain the nanostructured composite oxygen electrode material.

3. The preparation method according to claim 2, characterized in that, In step S4, the calcination temperature in the muffle furnace is 1100℃ and the calcination time is 10h.

4. The preparation method according to claim 2, characterized in that, In step S5, the ball milling speed is 450 r / min and the ball milling time is 5 h.

5. The application of the composite oxygen electrode material as described in claim 1 in solid oxide batteries.

6. A solid oxide battery prepared using the composite oxygen electrode material as described in claim 1, characterized in that, The preparation method involves the following steps: (1) The nanostructured composite oxygen electrode material was thoroughly ball-milled and mixed with a terpineol solution containing ethyl cellulose to obtain an electrode slurry; (2) The electrode slurry obtained in step (1) is coated onto the surface of the battery and then subjected to high temperature treatment to obtain a solid oxide battery.

7. The solid oxide battery according to claim 6, characterized in that, In step (1), the mass ratio of the composite oxygen electrode material powder to terpineol containing 10 wt.% ethyl cellulose is 1:1.2, the ball mill speed is 300 r / min, and the ball milling time is 5 h.

8. The solid oxide battery according to claim 6, characterized in that, In step (2), the high-temperature treatment temperature is 1100℃ and the heat preservation time is 2h.

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