Preparation method and application of SOFC anode support body

Abstract

The invention relates to the technical field of solid oxide fuel cells, in particular to a preparation method and application of an SOFC anode support. According to the method, NiO and YSZ are used as base materials, PVB is used as a binder, absolute ethyl alcohol is used as a ball milling medium, after ball milling mixing and drying, a composite pore forming agent is added for secondary ball milling, and then pressing and high-temperature calcination forming are performed. Wherein the composite pore-forming agent is formed by compounding a traditional pore-forming agent and microbial protein containing rare earth elements in proportion, a uniform pore structure is formed, the anode microstructure and catalytic activity are optimized through the rare earth elements, and the battery performance is remarkably improved. The method is simple and controllable in process, suitable for large-scale production of the high-performance SOFC anode support, good in application prospect and suitable for large-scale application of the high-performance solid oxide fuel cell.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells, and in particular to a preparation method and application of a SOFC anode support. Background Art

[0002] In recent years, rare earth elements (REEs) have become an essential component of modern technology, including energy production, environmental protection, digital technology, the nuclear industry, and medical applications. However, the rare earth mining process produces large amounts of wastewater containing significant amounts of REEs, which inevitably leads to the loss of REEs, severely damaging and polluting land and rivers, harming aquatic life and plants, causing bioaccumulation of toxic metals, and damaging biodiversity.

[0003] Solid oxide fuel cells (SOFCs) are energy conversion devices that directly convert the chemical energy of fuel into electricity and heat. They offer high energy conversion efficiency, are environmentally friendly, and hold enormous development potential. The anode is a key component of SOFCs, catalyzing the electrochemical reactions in the cell and providing an area for the electrochemical oxidation of the fuel gas. The microstructural parameters of the anode significantly influence SOFC performance, and these parameters are primarily determined by the pore-forming agent used. Currently, the most common pore-forming agents used in SOFC anodes include starch (such as corn starch and potato starch), carbon powder, graphite, and cellulose.

[0004] However, conventional pore-forming agents, in terms of improving anode porosity and electrochemical performance, are unable to meet the stringent structural and electrical conductivity requirements of high-performance SOFCs. Furthermore, a significant amount of valuable rare earth elements (REEs) in rare earth mine wastewater is not effectively recycled, resulting in both resource waste and a severe environmental burden. Therefore, there is an urgent need to develop a novel pore-forming agent and its preparation method that can both efficiently recover rare earth resources and significantly improve the microstructure and performance of SOFC anodes, thereby achieving the dual goals of enhancing material performance and addressing environmental challenges. Summary of the Invention

[0005] This application utilizes microorganisms to recover rare earth elements from rare earth mine wastewater to obtain microbial protein containing rare earth elements, and mixes it with traditional pore-forming agents in a certain proportion to prepare a composite pore-forming agent, which is applied to SOFC anode supports to improve the performance of SOFC.

[0006] In order to achieve the above objectives, the main technical solutions adopted by the present invention include: A method for preparing a SOFC anode support comprises the following steps: Step S1, NiO, YSZ and PVB were placed in a ball mill, anhydrous ethanol was added, and the mixture was ball milled at 260-280 r / min for 10 h; Step S2: drying the obtained mixed sample in an oven at 60-70°C, then placing it in a ball mill again, adding a composite pore-forming agent, and ball milling at 260-280 r / min for 2 h; Step S3: 0.3-0.5 parts of the ball-milled powder are placed in a 13 mm diameter grinding tool and prepared at a pressure of 6 MPa for 10-30 seconds to obtain a green body with a diameter of 13 mm. The green body is then calcined in a muffle furnace at 1100-1200° C. for 2-3 hours to obtain a SOFC anode support.

[0007] In a further embodiment, in step S2, the composite pore-forming agent is formed by mixing the rare earth element-containing microbial protein and the traditional pore-forming agent in a ratio of 70% to 90% by mass: 10% to 30% by mass.

[0008] In a further embodiment, the conventional pore former comprises soluble starch or carbon powder; the soluble starch comprises corn starch and potato starch.

[0009] In a further embodiment, the rare earth element-containing microbial protein is in powder form with a particle size of about 1-10 μm.

[0010] In a further embodiment, the mass ratio of NiO, YSZ and the composite pore former is 40-60:40-60:20-25.

[0011] In a further embodiment, the mass ratio of NiO, YSZ and the composite pore former is 40:60:20.

[0012] In a further embodiment, in step S1, the mass ratio of NiO, YSZ and PVB is 40-60:40-60:10-15, preferably 40:60:10.

[0013] In a further embodiment, the mass ratio of PVB, anhydrous ethanol and composite pore-forming agent is 10-15:75-80:20-25, preferably 10:75:20.

[0014] In a further embodiment, the rare earth element-containing microbial protein is prepared by the following steps: Step 1, adding rare earth mine wastewater to a basic culture medium to obtain a first mixed solution; Step 2: inoculating the activated hydrogen oxidizing bacteria liquid into the first mixed liquid to obtain a second mixed liquid; Step 3: transferring the second mixed liquid to a reactor, introducing a mixed gas containing CO2, O2 and H2 and then culturing the mixed liquid, thereby fermenting the microbial protein containing rare earth elements using the hydrogen oxidizing bacteria; In step 2, the hydrogen oxidizing bacteria include the following bacteria in relative abundance: Hydrogenophaga 30%-70%; and Xanthobacter 70%-30%; the volume ratio of the activated hydrogen oxidizing bacteria liquid, the basic culture medium and the rare earth mine wastewater in the second mixed solution is (15%-25%): (25%-35%): (45%-55%).

[0015] In the second mixed solution, the volume ratio of the activated hydrogen oxidizing bacteria liquid described in step 2, the basic culture medium and the rare earth mine wastewater is 20%:30%:50%.

[0016] In a further embodiment, in step 3, the volume ratio of CO2, O2 and H2 in the mixed gas is (13-17): (23-27): (58-62); the purge frequency of the mixed gas is 10-14h, and the purge time is 2-5min.

[0017] The hydraulic retention time of the second mixed liquid in step 3 in the reactor is 5 days.

[0018] During the cultivation process described in step 3, aeration treatment is performed every 12-36 hours, and the duration of each aeration treatment is 2-3 minutes.

[0019] The culture temperature of the reactor described in step 3 is 25-35°C.

[0020] In step 3, the step of obtaining microbial protein is as follows: centrifuging the bacterial community in the fermentation system in the reactor at 8000-12000 rpm for 5-15 minutes, discarding the supernatant, and leaving the precipitate; washing the precipitate with deionized water and centrifuging it again, centrifuging it at 8000-12000 rpm for 5-15 minutes, repeating the washing and centrifugation 1-3 times to obtain a washed precipitate; placing the washed precipitate in an oven at 100-110°C for 20-28 hours to finally obtain microbial protein.

[0021] Rare earth mine wastewater is ionic rare earth mine wastewater.

[0022] The present invention provides application of the above-mentioned SOFC anode support in SOFC.

[0023] Compared with the prior art, the present invention has the following advantages: This invention provides a method for preparing a SOFC anode support. The method involves using NiO and YSZ as matrix materials, PVB as a binder, and anhydrous ethanol as a ball-milling medium. The materials are ball-milled for a long time at a specific speed to achieve uniform mixing. After drying, a composite pore-forming agent is introduced and ball-milled again. After pressing and high-temperature calcination, an anode support with a stable structure and excellent performance is obtained. The introduction of the composite pore-forming agent is a key factor in improving anode performance. This composite pore-forming agent is a combination of a traditional pore-forming agent (such as soluble starch or carbon powder) and a microbial protein containing rare earth elements. This composite pore-forming agent not only retains the ability of traditional pore-forming agents to form a porous structure during high-temperature burnout, but also further optimizes the anode material's microstructure and catalytic activity through the rare earth elements enriched in the microbial protein. The rare earth element-microbial protein complex helps enhance the anode's conductivity and the diffusion efficiency of the reactant gases, significantly improving the cell's porosity and peak power density, ultimately achieving even better battery performance. The method of the present invention is process-controllable and easy to operate. The prepared anode support has excellent pore structure and electrochemical properties, and is suitable for large-scale application of high-performance solid oxide fuel cells.

[0024] Microbial proteins containing rare earth elements are obtained through wastewater treatment. Rare earth mine wastewater and additional basal culture medium are used as the growth medium for hydrogen-oxidizing bacteria. Because rare earth cations can replace potassium, sodium, and other cations in the bacteria, they can enter the bacteria, enriching the rare earth elements in the wastewater and producing microbial proteins containing rare earth elements. This not only recovers rare earth elements from rare earth mine wastewater, alleviating downstream processing pressure, but also allows the recovered rare earth elements to be used in batteries through a biofermentation process, generating certain economic benefits and thus achieving the coordinated development of the economy and the ecology. DETAILED DESCRIPTION

[0025] In order to make the content of the present invention easier to understand, the technical scheme of the present invention is further described below in conjunction with specific examples, but the present invention is not limited thereto. All technologies realized based on the above content of the present invention are encompassed within the scope that the present invention is intended to protect. Unless otherwise stated, the raw materials and reagents used in the examples are all commercially available products. Reagents, instruments or operating procedures not recorded herein are all contents that can be routinely determined by those of ordinary skill in the art.

[0026] The present application provides these embodiments to make this application thorough and complete, and to fully express the scope of this application to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of the steps, the components of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0027] It should be noted that, in the description of this application, unless otherwise specified, “multiple” means greater than or equal to two.

[0028] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0029] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0030] In order to explain the present application more clearly, the present application is further described below in conjunction with preferred embodiments. Those skilled in the art should understand that the following specific description is illustrative rather than restrictive and should not be used to limit the scope of protection of the present invention.

[0031] In this application, parts and percentages are by mass unless otherwise stated.

[0032] In this application, YSZ is ZrO2 doped with 8 mol% Y2O3.

[0033] In the present application, the term "hydrogen oxidizing bacteria" refers to microorganisms that can use hydrogen as an electron donor to reduce carbon dioxide to organic matter.

[0034] In the present invention, the term "purging" refers to the process of introducing gas into the fermentation tank during the microbial fermentation process to purge the gas inside the fermentation tank from the previous day and introduce gas configured in a certain proportion to ensure that the gas in the fermentation tank can react according to the same proportion of gas every day.

[0035] In this application, the term "fermentation system" refers to a fermentation system composed of bacterial flora and culture medium cultured in a reactor, and formally refers to a mixture of bacterial flora and mixed biological culture medium.

[0036] In this application, the term "microbial protein containing rare earth elements" refers to the bacterial cytoplasm composed of a mixture of proteins, carbohydrates, nucleic acids, fats, non-protein nitrogenous compounds, vitamins and inorganic compounds produced by bacteria, fungi, yeast or algae under a suitable growth environment.

[0037] In this application, the term "battery" refers to a solid oxide fuel cell (SOFC), an energy conversion device that can directly convert the chemical energy of a fuel into electrical energy and thermal energy. In this application, the term "anode support" refers to the basic functional component unit of a solid oxide fuel cell.

[0038] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=100:0.

[0039] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=90:10.

[0040] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=80:20.

[0041] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=70:30.

[0042] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=100:0.

[0043] In some embodiments, NiO:YSZ:composite pore-forming agent=50:50:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=70:30.

[0044] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=100:0.

[0045] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=90:10.

[0046] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=80:20.

[0047] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=70:30.

[0048] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=60:40.

[0049] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=50:50.

[0050] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=100:0.

[0051] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=90:10.

[0052] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=80:20.

[0053] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=70:30.

[0054] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=60:40.

[0055] In some embodiments, NiO:YSZ:composite pore-forming agent=40:60:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=50:50.

[0056] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=100:0.

[0057] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=90:10.

[0058] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=80:20.

[0059] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is soluble starch:microbial protein containing rare earth elements=70:30.

[0060] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=100:0.

[0061] In some embodiments, NiO:YSZ:composite pore-forming agent=60:40:20, wherein the composite pore-forming agent is carbon powder:microbial protein containing rare earth elements=70:30.

[0062] Example 1 (1) Prepare basal culture medium and add ionic rare earth mine wastewater The formula of the basal culture medium contains the following substances per liter of solution: 6.4g of glucose, 1.0g of ammonium chloride, 2.9g of disodium hydrogen phosphate, 0.01g of calcium chloride, 0.5g of magnesium sulfate, 0.5g of sodium bicarbonate, 2.3g of potassium dihydrogen phosphate, 0.05g of ammonium ferric citrate, 0.2mg of zinc sulfate, 0.4mg of cobalt chloride, 0.6mg of boric acid, 0.06mg of sodium molybdate, 0.04mg of nickel chloride, 0.02mg of copper sulfate, and 0.06mg of manganese chloride.

[0063] Ionic rare earth mine wastewater was added to a reactor containing a basal culture medium to obtain a first mixed solution, which was then sterilized at 121° C. for 20 min.

[0064] (2) First, activate the hydrogen oxidizing bacteria. The activation method is to use a 500 mL blue-mouth bottle with a working volume of 150 mL and a headspace volume of 450 mL. The inoculum is 20% of the acclimated hydrogen oxidizing bacteria solution. The culture medium uses the basic culture medium of step (1), and the ammonia nitrogen concentration is adjusted to 1000 mg N / L. In order to make the hydrogen oxidizing bacteria recover faster, 24.75 g / L of glucose is added to it to adjust the carbon-nitrogen ratio to 9. The headspace is purged with a mixture of CO2:O2:H2=15:25:60 and a pressure of 1 bar for 3 minutes. After completion, it is sealed and the headspace is purged once every 12 hours. The pH of the culture medium is adjusted to 7.0 every day with 2 mol / L HCl and 2 mol / L NaOH. The temperature is fixed at 28°C and the speed is set at 160 rpm. The activated hydrogen oxidizing bacteria liquid is inoculated into the first mixed liquid to obtain a second mixed liquid, wherein the second mixed liquid consists of 20 volume % of the activated hydrogen oxidizing bacteria liquid, 30 volume % of the basic culture medium and 50 volume % of the ionic rare earth mine wastewater.

[0065] The second mixed solution was then cultured in a constant temperature shaking incubator at a temperature of 28° C. for 5 days. The pH of the second mixed solution was 7.0±0.2, and the shaking rate of the constant temperature shaking incubator was 160 rpm.

[0066] (3) The second mixed solution from step (2) was transferred to a reactor and incubated with a mixed gas at 28°C. The mixed gas contained CO₂, O₂, and H₂ in a volume ratio of CO₂:O₂:H₂ of 15:25:60. The purge frequency of the mixed gas was 12 hours, and each purge lasted 3 minutes. In the reactor, the volume of the second mixed solution:headspace volume was 150:450.

[0067] (4) Water is introduced into and out of the reactor every day to aerate the reaction system; In step (4), the water inlet and outlet of the reactor were 50 mL per day, where "inlet" refers to the one-time addition of 50 mL of basal culture medium and "outlet" refers to the one-time discharge of 50 mL of fermentation liquid. The hydraulic retention time was 5 days. In step (4), the fermentation system in the reactor is aerated once every 24 hours, and the duration of each aeration treatment is 3 minutes.

[0068] (5) After 15 days of cultivation, the bacterial colony in the fermentation system in the reactor was centrifuged at 8000 rpm for 10 minutes, and the supernatant was discarded, leaving the precipitate. The precipitate was washed with deionized water and centrifuged again, and then centrifuged at 10000 rpm for 10 minutes. The washing and centrifugation were repeated three times to obtain a washed precipitate. The washed precipitate was placed in an oven at 100°C for 25 hours to obtain a microbial protein containing rare earth elements. The changes in rare earth element concentration and recovery rate in Example 1 are shown in Table 1.

[0069] Table 1: Changes in concentrations and recovery rates of key rare earth elements in Example 1 The rare earth element content of the microbial protein containing rare earth elements is 0.05% by weight, and the microbial protein content is 66% by weight. The microbial protein contains 18 amino acids, of which the essential amino acids lysine, methionine, phenylalanine, isoleucine, leucine, threonine, valine, and tryptophan account for 9%, 2%, 6%, 11%, 7%, 4%, and 5% by weight, respectively. The remaining 11 non-essential amino acids account for a total of 56% by weight.

[0070] (6) The soluble starch and the rare earth element-containing microbial protein obtained in step (5) are mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0071] (7) The mass fractions are as follows: NiO:YSZ:composite pore-forming agent = 50:50:20, NiO:YSZ:PVB = 50:50:10, PVB:anhydrous ethanol:composite pore-forming agent = 10:75:20. NiO, YSZ and PVB are placed in a ball mill, an appropriate amount of anhydrous ethanol is added, and the mixture is ball milled at 260 r / min for 10 h. The obtained sample is placed in a 60°C oven for drying and then placed in a ball mill again, the composite pore-forming agent obtained in step (5) is added, and the mixture is ball milled at 260 r / min for 2 h. 0.3 parts of the ball-milled powder are taken and placed in a 13 mm diameter grinding tool and a pressure of 6 MPa is used to prepare an anode support body, obtaining a 13 mm diameter blank, which is then calcined at 1100°C in a muffle furnace for 2 h to obtain an anode support body.

[0072] (8) The anode support in step (7) is used in a solid oxide fuel cell. The cell is installed in a tubular resistance furnace. Ceramic sealant is used as a sealing material. Silver paste and silver wire are used to collect current. The performance of the cell is tested at 750°C.

[0073] In step (8), a DC electronic load and an electrochemical workstation are used to test the battery. Electrochemical performance tests were performed and morphology analysis was performed using a field emission scanning electron microscope.

[0074] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 2. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 2, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 23.58%. And the peak power density of the battery obtained after testing is 0.92W / cm 2 .

[0075] Table 2: Final anode support porosity and battery peak power density in Example 1 Example 2 Example 1 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent, and the particle size of the rare earth element-containing microbial protein was 10 μm.

[0076] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 3. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 3, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 90:10 to form a composite pore-forming agent is 25.77%. And the peak power density of the battery obtained after testing is 1.06W / cm 2 .

[0077] Table 3: Final anode support porosity and battery peak power density in Example 2 Example 3 Example 1 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent, and the particle size of the rare earth element-containing microbial protein was 1 μm.

[0078] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 4. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 4, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 80:20 to form a composite pore-forming agent is 28.37%. And the peak power density of the battery obtained after testing is 1.19W / cm 2 .

[0079] Table 4: Final anode support porosity and battery peak power density in Example 3 Example 4 Example 1 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent, and the particle size of the rare earth element-containing microbial protein was 5 μm.

[0080] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 5. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 5, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 30.31%. And the peak power density of the battery obtained after testing is 1.26W / cm 2 .

[0081] Table 5: Final anode support porosity and battery peak power density in Example 4 Furthermore, cross-testing (i.e., comparative experiments based on this example using microbial protein containing rare earth elements with particle sizes of 1 μm, 3 μm, 5 μm, 7 μm, and 10 μm) revealed that the 5 μm particle size sample exhibited the best performance. Therefore, in the subsequent examples and comparative examples, a 5 μm particle size microbial protein containing rare earth elements was used.

[0082] 1μm experimental data: porosity is 29.33%, peak power density is 1.09 (W / cm 2) ; 3μm experimental data: porosity (%) is 30.02%, peak power density (W / cm 2) ; 7μm experimental data: porosity (%) is 29.87.31%, peak power density (W / cm 2) ; 10μm experimental data: porosity (%) is 29.66%, peak power density (W / cm 2) .

[0083] When the particle size is too small, although the specific surface area is large, which is conducive to the dispersion and catalytic effect of rare earth elements, the particles are too fine and easily clogged or agglomerated during high-temperature calcination, resulting in some pores not being effectively formed, resulting in relatively low porosity and electrochemical performance. When the particle size is too large, although the gaps between the particles are large, they are unevenly distributed in the material, easily forming localized large pores, destroying the uniformity of the overall pore structure, thereby reducing the effective specific surface area of ​​the material and the continuity of the conductive network, ultimately leading to a decline in battery performance.

[0084] The 5μm rare earth element-containing microbial protein can achieve a good balance between pore formation, rare earth element release and distribution, and microstructure regulation, and is an ideal choice for preparing high-performance SOFC anode supports.

[0085] Example 5 Example 1 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0086] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 6. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 6, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 21.68%. The peak power density of the battery obtained after testing is 0.87W / cm2 .

[0087] Table 6: Final anode support porosity and battery peak power density in Example 5 Example 6 Example 1 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0088] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 7. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 7, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 27.15%. And the peak power density of the battery obtained after testing is 1.14W / cm 2 .

[0089] Table 7: Final anode support porosity and battery peak power density in Example 6 Example 7 Example 1 was repeated, and the changes in rare earth element concentration and recovery rates in Example 7 are shown in Table 8. The only difference is that in step (7), the mass fractions of NiO:YSZ:composite pore-forming agent = 40:60:20, NiO:YSZ:PVB = 40:60:10, and PVB:anhydrous ethanol:composite pore-forming agent = 10:75:20.

[0090] NiO, YSZ, and PVB were placed in a ball mill, and an appropriate amount of anhydrous ethanol was added. The mixture was ball milled at 260 r / min for 10 h. The obtained sample was placed in a 60°C oven for drying and then placed in a ball mill again. The composite pore-forming agent obtained in step (5) was added and the mixture was ball milled at 260 r / min for 2 h. 0.3 parts of the ball-milled powder were taken and placed in a 13 mm diameter grinding tool. The anode support was prepared using a pressure of 6 MPa to obtain a blank with a diameter of 13 mm. The blank was calcined in a muffle furnace at 1100°C for 2 h to finally obtain the anode support. The changes in rare earth element concentration and recovery rate in Example 7 are shown in Table 8.

[0091] Table 8: Changes in concentrations and recovery rates of key rare earth elements in Example 7 The rare earth element content of the rare earth element-containing microbial protein is 0.08% by weight, while the microbial protein content is 62% by weight. The microbial protein contains 18 amino acids, including 12%, 4%, 4%, 9%, 5%, 7%, and 6% by weight of the essential amino acids lysine, methionine, phenylalanine, isoleucine, leucine, threonine, valine, and tryptophan, respectively. The remaining 11 non-essential amino acids account for a total of 53% by weight.

[0092] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 9. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 9, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 26.33%. The peak power density of the battery obtained after testing is 1.09W / cm 2 .

[0093] Table 9: Final anode support porosity and battery peak power density in Example 7 Example 8 Example 7 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0094] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 10. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 10, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 90:10 to form a composite pore-forming agent is 29.46%. And the peak power density of the battery obtained after testing is 1.21W / cm 2 .

[0095] Table 10: Final anode support porosity and battery peak power density in Example 8 Example 9 Example 7 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0096] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 11. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 11, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 80:20 to form a composite pore-forming agent is 33.40%. And the peak power density of the battery obtained by testing is 1.35W / cm 2 .

[0097] Table 11: Final anode support porosity and battery peak power density in Example 9 Example 10 Example 7 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0098] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 12. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 12, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 35.59%. And the peak power density of the battery obtained after testing is 1.42W / cm 2 .

[0099] Table 12: Final anode support porosity and battery peak power density in Example 10 Example 11 Example 7 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 60:40 to prepare a composite pore-forming agent.

[0100] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 13. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 13, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 60:40 to form a composite pore-forming agent is 30.25%. And the peak power density of the battery obtained after testing is 1.23W / cm 2 .

[0101] Table 13: Final anode support porosity and battery peak power density in Example 11 Example 12 Example 7 was repeated, except that in step (6), the soluble starch and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 50:50 to prepare a composite pore-forming agent.

[0102] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 14. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 14, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 50:50 to form a composite pore-forming agent is 27.89%. And the peak power density of the battery obtained after testing is 1.16W / cm 2 .

[0103] Table 14: Final anode support porosity and battery peak power density in Example 12 Example 13 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0104] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 15. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 15, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 25.38%. The peak power density of the battery obtained after testing is 1.05W / cm 2 .

[0105] Table 15: Final anode support porosity and battery peak power density in Example 13 Example 14 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0106] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 16. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 16, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 90:10 to form a composite pore-forming agent is 27.41%. The peak power density of the battery obtained after testing is 1.15W / cm 2 .

[0107] Table 16: Final anode support porosity and battery peak power density in Example 14 Example 15 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0108] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 17. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 17, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 80:20 to form a composite pore-forming agent is 29.18%. The peak power density of the battery obtained after testing is 1.20W / cm 2 .

[0109] Table 17: Final anode support porosity and battery peak power density in Example 15 Example 16 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0110] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 18. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 18, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 32.96%. The peak power density of the battery obtained after testing is 1.33W / cm 2 .

[0111] Table 18: Final anode support porosity and battery peak power density in Example 16 Example 17 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 60:40 to prepare a composite pore-forming agent.

[0112] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 19. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 19, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 60:40 to form a composite pore-forming agent is 28.20%. The peak power density of the battery obtained after testing is 1.18W / cm 2 .

[0113] Table 19: Final anode support porosity and battery peak power density in Example 17 Example 18 Example 7 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 50:50 to prepare a composite pore-forming agent.

[0114] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 20. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 20, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 50:50 to form a composite pore-forming agent is 26.95%. The peak power density of the battery obtained after testing is 1.12W / cm 2 .

[0115] Table 20: Final anode support porosity and battery peak power density in Example 18 Example 19 Example 1 was repeated, except that in step (7), the ratio of NiO:YSZ:composite pore-forming agent was 60:40:20, NiO:YSZ:PVB was 60:40:10, and PVB:anhydrous ethanol:composite pore-forming agent was 10:75:20. NiO, YSZ, and PVB were placed in a ball mill, an appropriate amount of anhydrous ethanol was added, and the mixture was ball milled at 260 r / min for 10 h. The obtained sample was placed in an oven for drying and then placed in a ball mill again, the composite pore-forming agent obtained in step (5) was added, and the mixture was ball milled at 260 r / min for 2 h. 0.3 parts of the ball-milled powder was taken and placed in a 13 mm diameter grinding tool and a pressure of 6 MPa was used to prepare an anode support, obtaining a blank with a diameter of 13 mm. The blank was calcined at 1100°C in a muffle furnace for 2 h to obtain an anode support.

[0116] The changes in rare earth element concentration and recovery rate in Example 19 are shown in Table 21.

[0117] Table 21: Changes in concentrations and recovery rates of key rare earth elements in Example 19 The rare earth element-containing microbial protein contains 0.04% rare earth elements by weight, 64% microbial protein by weight, and 18 amino acids. The essential amino acids lysine, methionine, phenylalanine, isoleucine, leucine, threonine, valine, and tryptophan account for 15%, 6%, 4%, 8%, 6%, 5%, and 6% of the weight, respectively. The remaining 11 non-essential amino acids account for a total of 50% by weight.

[0118] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 22. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 22, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 21.12%. The peak power density of the battery obtained after testing is 0.86W / cm 2 .

[0119] Table 22: Final anode support porosity and battery peak power density in Example 19 Example 20 Example 19 was repeated, except that the soluble starch in step (6) and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0120] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 23. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 23, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 90:10 to form a composite pore-forming agent is 23.03%. And the peak power density of the battery obtained after testing is 0.91W / cm 2 .

[0121] Table 23: Final anode support porosity and battery peak power density in Example 20 Example 21 Example 19 was repeated, except that the soluble starch in step (6) and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0122] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 24. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 24, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 80:20 to form a composite pore-forming agent is 24.92%. And the peak power density of the battery obtained after testing is 0.99W / cm 2 .

[0123] Table 24: Final anode support porosity and battery peak power density in Example 21 Example 22 Example 19 was repeated, except that the soluble starch in step (6) and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0124] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 25. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As can be seen from Table 25, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 27.64%. And the peak power density of the battery obtained after testing is 1.16W / cm 2 .

[0125] Table 25: Final anode support porosity and battery peak power density in Example 22 Example 23 Example 19 was repeated, except that in step (6), the carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0126] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 26. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 26, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 100:0 to form a composite pore-forming agent is 20.45%. The peak power density of the battery obtained after testing is 0.83W / cm 2 .

[0127] Table 26: Final anode support porosity and battery peak power density in Example 23 Example 24 Example 19 was repeated, except that in step (6), carbon powder and the rare earth element-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0128] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under 750°C are shown in Table 27. From the microstructure, it can be observed that the battery has formed a uniform porous structure. As shown in Table 27, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 26.38%. The peak power density of the battery obtained after testing is 1.11W / cm 2 .

[0129] Table 27: Final anode support porosity and battery peak power density in Example 24 The results of Examples 1-24 show that as the rare earth element protein content in the composite pore-forming agent prepared by mixing soluble starch with rare earth element-containing microbial protein increases, the porosity and peak power density gradually increase. This indicates that the addition of rare earth element-containing microbial protein has a significant effect on SOFC battery performance, with the composite pore-forming agent containing soluble starch and rare earth element-containing microbial protein in a ratio of 70:30 exhibiting the best performance. Comparing the results of Examples 1-6, Examples 7-18, and Examples 19-24, the pore-forming agent and SOFC battery performance were both optimal when the NiO:YSZ:composite pore-forming agent ratio was 40:60:20. However, when the NiO:YSZ:composite pore-forming agent ratio was 60:40:20, both the pore-forming agent and SOFC battery performance decreased.

[0130] The results of Examples 5, 13, and 23 show that using only carbon powder as a pore-forming agent yielded unsatisfactory pore-forming results and battery performance. However, compared to the results of Examples 6, 14-18, and 24, the addition of rare earth element-containing microbial protein powder to carbon powder to form a composite pore-forming agent significantly improved both porosity and peak power density, further demonstrating that the addition of rare earth element-containing microbial protein can significantly improve SOFC battery performance. The above examples also demonstrate that composite pore-forming agents prepared by mixing rare earth element-containing microbial protein with other traditional pore-forming agents also exhibited promising results.

[0131] In order to clarify whether the effect of the composite pore-forming agent on improving the performance of the SOFC anode is caused by the rare earth element itself or by the formation of a complex between the rare earth element and the microbial protein, the present invention further provides comparative examples 1 and 2 for comparative verification.

[0132] Comparative Example 1 Example 10 was repeated except that the rare earth element-containing microbial protein in Example 10 was replaced with an equal amount of a mixture A of the key rare earth elements. The equal amount refers to an equal amount of the key rare earth elements.

[0133] In step (6), the soluble starch and the above mixture A are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0134] The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 28. From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. As can be seen from Table 28, the porosity of the anode support prepared by mixing soluble starch and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 30.17%. The peak power density of the battery obtained after testing is 1.22W / cm 2 .

[0135] Table 28: Final anode support porosity and battery peak power density in Comparative Example 1 Comparative Example 2 Example 10 was repeated except that the rare earth element-containing microbial protein in Example 10 was replaced with an equal amount of a mixture A of the key rare earth elements. The equal amount refers to an equal amount of each rare earth element.

[0136] In step (6), the carbon powder and the above mixture A are mixed in a ratio of 70:30 to prepare a composite pore-forming agent. The porosity of the anode support obtained in the final test of this embodiment and the peak power density of the single cell under the condition of 750°C are shown in Table 29. From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. As can be seen from Table 29, the porosity of the anode support prepared by mixing carbon powder and protein powder in a ratio of 70:30 to form a composite pore-forming agent is 28.24%. And the peak power density of the battery obtained after testing is 1.18W / cm 2 .

[0137] Table 29: Final anode support porosity and battery peak power density in Comparative Example 2 Comparative Example 3 Example 10 was repeated except that the rare earth element-containing microbial protein in Example 10 was replaced with a mixture B formed by equal amounts of key rare earth element oxides. Equal amounts refer to equal amounts of each rare earth element.

[0138] In step (6), the soluble starch and the above mixture B are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0139] From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. The porosity of the anode support prepared with the composite pore-forming agent is 31.22%. The peak power density of the battery was 1.23W / cm 2 .

[0140] Comparative Example 4 Example 10 was repeated except that the rare earth element-containing microbial protein in Example 10 was replaced with a mixture C formed of equal amounts of rare earth element oxides. Equal amounts refer to equal amounts of each rare earth element.

[0141] In step (6), the carbon powder and the above mixture C are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0142] From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. The porosity of the anode support prepared with the composite pore-forming agent is 29.41%. The peak power density of the battery was 1.20W / cm 2 .

[0143] Comparative Example 5 Example 10 was repeated except that an equal amount of rare earth element mixture D in sulfate form was substituted for the rare earth element-containing microbial protein in Example 10. "Equal amount" means that the rare earth element content in the sulfate form of the rare earth element is equal to the rare earth element content in the rare earth element-containing microbial protein.

[0144] In step (6), the soluble starch and the above mixture D are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0145] From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. The porosity of the anode support prepared with the composite pore-forming agent is 31.45%. The peak power density of the battery was 1.29W / cm 2 .

[0146] Comparative Example 6 The only difference is that the rare earth element-containing microbial protein in Example 10 is replaced with equal amounts of the key rare earth element in sulfate form and mixture E. Equal amounts means that the rare earth element content in the rare earth element in sulfate form is equal to the key rare earth element content in the rare earth element-containing microbial protein.

[0147] In step (6), the carbon powder and the above mixture E are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0148] From the microstructure, it can be observed that the battery has formed a non-uniform porous structure. The porosity of the anode support prepared with the composite pore-forming agent is 30.09%. The peak power density of the battery was 1.19W / cm 2 .

[0149] Comparing the experimental results of Example 10 with Comparative Examples 1-6 clearly demonstrates that rare earth element-containing microbial protein significantly outperforms pure rare earth elements in improving SOFC anode performance. This may be because the microbial protein not only effectively enriches rare earth elements as a carrier but also forms a stable complex structure between the protein and the rare earth elements. This complex releases the rare earth elements more evenly during high-temperature sintering and forms active sites around them, thereby optimizing the anode's microstructure and enhancing conductivity and catalytic activity. Simply adding rare earth elements, however, struggles to achieve such uniform distribution and is prone to agglomeration or localized over-concentration, resulting in uneven pore structure and reduced performance. Therefore, the complex formed by rare earth element-containing microbial protein is key to improving anode performance.

[0150] In order to clarify the effect of the composite pore-forming agent on improving the performance of SOFC anodes and the influence of the ratio of NiO:YSZ:composite pore-forming agent:PVB:anhydrous ethanol, comparative examples 7-10 were set.

[0151] Comparative Example 7 Example 10 was repeated, except that the mass ratio of NiO, YSZ and the composite pore former was 40:60:15.

[0152] The porosity of the anode support and the peak power density of the single cell at 750° C. obtained from the final test in this embodiment are 31.26 and 1.28, respectively.

[0153] Comparative Example 8 Example 10 was repeated, except that the mass ratio of NiO, YSZ and the composite pore-forming agent was 40:60:30.

[0154] The porosity of the anode support and the peak power density of the single cell at 750° C. obtained from the final test in this embodiment are 32.18 and 1.31, respectively.

[0155] Comparative Example 9 Example 10 was repeated, with the mass ratio of NiO, YSZ and composite pore-forming agent being 40:60:20, except that NiO:YSZ:PVB=40:60:30, and PVB:anhydrous ethanol:composite pore-forming agent=30:75:20.

[0156] The porosity of the anode support and the peak power density of the single cell at 750° C. obtained from the final test in this embodiment are 33.89 and 1.38, respectively.

[0157] Comparative Example 10 Example 10 was repeated, with the mass ratio of NiO, YSZ and composite pore-forming agent being 40:60:20, except that the mass ratios of NiO:YSZ:PVB were 40:60:10 and PVB:anhydrous ethanol:composite pore-forming agent were 10:50:20.

[0158] The porosity of the anode support and the peak power density of the single cell at 750° C. obtained from the final test in this embodiment are 32.87 and 1.32, respectively.

[0159] The experimental results from Comparative Examples 7 to 10 show that the ratio of NiO, YSZ, composite pore-forming agent, PVB, and anhydrous ethanol has a certain impact on the performance of the SOFC anode support. When the NiO:YSZ:composite pore-forming agent ratio deviates from the optimized range (such as 40:60:15 in Comparative Example 7 or 40:60:30 in Comparative Example 8), the anode porosity and peak power density both decrease. This indicates that too low a pore-forming agent content is detrimental to the formation of a sufficient pore structure, while too high a pore-forming agent content disrupts the continuity and conductive network of the matrix material, thus limiting performance improvements.

[0160] In addition, the ratio of PVB binder to anhydrous ethanol ball milling medium also has an important influence. Based on the ratio of NiO:YSZ:composite pore former = 40:60:20, comparative example 9 (PVB dosage increased to 30) showed relatively good performance (porosity 33.89%, power density 1.38 W / cm 2 ), indicating that appropriately increasing the binder helps to evenly disperse the powder and form the embryo. However, if the proportion of anhydrous ethanol is too low (for example, ethanol is reduced to 50 in Comparative Example 10), it will affect the ball milling effect and component uniformity, thereby reducing the final performance.

[0161] In summary, only at the optimized ratio of NiO:YSZ:composite pore-forming agent = 40:60:20, PVB:anhydrous ethanol:composite pore-forming agent = 10:75:20 can the optimal balance between the uniformity of material structure, the rationality of pore distribution and electrochemical performance be achieved, thereby obtaining the optimal battery performance.

[0162] Therefore, the technology of preparing composite pore-forming agents using rare earth element-containing microbial proteins obtained by microbial fermentation is completely feasible, and its use in SOFC has a good effect on improving battery performance.

[0163] Thus far, various embodiments of the present invention have been described in detail. To avoid obscuring the concept of the present invention, some details well known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions of the present invention.

[0164] Although some specific embodiments of the present invention have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present invention. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts.

Claims

1. A method for preparing a SOFC anode support, characterized in that: The steps include: Step S1, NiO, YSZ and PVB were placed in a ball mill, anhydrous ethanol was added, and the mixture was ball milled at 260-280 r / min for 10 h; Step S2: drying the obtained mixed sample in an oven and then placing it in a ball mill again, adding a composite pore-forming agent, and ball milling at 260-280 r / min for 2 h; Step S3: Take 0.3-0.5 parts of the ball-milled powder, put it into a 13 mm diameter grinding tool and grind it under a pressure of 6 MPa for 30-60 seconds to obtain a green body with a diameter of 13 mm, and calcine it in a muffle furnace at 1100-1200° C. for 2-3 hours to obtain a SOFC anode support.

2. The method for preparing a SOFC anode support according to claim 1, wherein: In step S2, the composite pore-forming agent is prepared by mixing the rare earth element-containing microbial protein and the traditional pore-forming agent in a ratio of 70% to 90% by mass: 10% to 30% by mass.

3. The method for preparing a SOFC anode support according to claim 2, characterized in that: The conventional pore formers include soluble starch or carbon powder.

4. The method for preparing a SOFC anode support according to claim 3, characterized in that: The rare earth element-containing microbial protein is in powder form with a particle size of 1-10 μm.

5. The method for preparing a SOFC anode support according to claim 1, wherein: The mass ratio of NiO, YSZ and composite pore former is 40-60:40-60:20-25.

6. The method for preparing a SOFC anode support according to claim 1, wherein: Preferably, the mass ratio of NiO, YSZ and the composite pore-forming agent is 40:60:

20.

7. The method for preparing a SOFC anode support according to claim 1, wherein: The mass ratio of NiO, YSZ and PVB is 40-60:40-60:10-15.

8. The method for preparing a SOFC anode support according to claim 2, wherein: The rare earth element-containing microbial protein is prepared by the following steps: Step 1, adding rare earth mine wastewater to a basic culture medium to obtain a first mixed solution; Step 2: inoculating the activated hydrogen oxidizing bacteria liquid into the first mixed liquid to obtain a second mixed liquid; Step 3: transferring the second mixed liquid to a reactor, introducing a mixed gas containing CO2, O2 and H2 and then culturing the mixed liquid, thereby fermenting the microbial protein containing rare earth elements using the hydrogen oxidizing bacteria; In step 2, the hydrogen oxidizing bacteria include the following bacteria in relative abundance: Hydrogenophaga 30%-70%; and Xanthobacter 70%-30%; the volume ratio of the activated hydrogen oxidizing bacteria liquid, the basic culture medium and the rare earth mine wastewater in the second mixed solution is (15%-25%): (25%-35%): (45%-55%).

9. The method for preparing a SOFC anode support according to claim 8, characterized in that: In step 3, the volume ratio of CO2, O2 and H2 in the mixed gas is (13-17): (23-27): (58-62); In step 3, the step of obtaining microbial protein is as follows: centrifuging the bacterial community in the fermentation system in the reactor at 8000-12000 rpm for 5-15 minutes, discarding the supernatant, and leaving the precipitate; washing the precipitate with deionized water and centrifuging it again, centrifuging it at 8000-12000 rpm for 5-15 minutes, repeating the washing and centrifugation 1-3 times to obtain a washed precipitate; placing the washed precipitate in an oven at 100-110°C for 20-28 hours to finally obtain microbial protein.

10. Use of the SOFC anode support according to claim 1 in SOFC.

Images