A method for preparing SOFC anode support and its application

Abstract

This invention relates to the field of solid oxide fuel cell technology, specifically to a method for preparing and applying an SOFC anode support. The method uses NiO and YSZ as matrix materials, PVB as a binder, and anhydrous ethanol as the ball milling medium. After ball milling and drying, a composite pore-forming agent is added and ball milled again, followed by pressing and high-temperature calcination. The composite pore-forming agent is a mixture of a traditional pore-forming agent and a microbial protein containing rare earth elements, which not only forms a uniform porous structure but also optimizes the anode microstructure and catalytic activity through rare earth elements, significantly improving battery performance. This invention features a simple and controllable process, suitable for the large-scale production of high-performance SOFC anode supports, and has promising application prospects for large-scale applications in high-performance solid oxide fuel cells.

Description

Technical Field

[0001] This invention relates to the field of solid oxide fuel cell technology, specifically to a method for preparing and applying an SOFC anode support. Background Technology

[0002] In recent years, rare earth elements have become an important component of modern technology fields such as energy production, environmental protection, digital technology, nuclear industry, and medical applications. However, the rare earth mining process generates a large amount of wastewater containing high levels of rare earth elements, inevitably leading to the loss of these elements, severely damaging and polluting land and rivers, harming aquatic organisms and plants, causing the accumulation of toxic metals in organisms, and destroying biodiversity.

[0003] Solid oxide fuel cells (SOFCs) are energy conversion devices that directly convert the chemical energy of fuel into electrical and thermal energy. They offer high energy conversion efficiency, are environmentally friendly, and have enormous development potential. The anode is a crucial component of an SOFC, catalyzing the electrochemical reactions within the cell and providing the region for the electrochemical oxidation of the fuel gas. The microstructure parameters of the anode significantly influence the performance of the SOFC, and these parameters primarily depend on the pore-forming agent used. Currently, commonly used traditional pore-forming agents in SOFC anodes include starch (such as corn starch and potato starch), carbon powder, graphite, and cellulose.

[0004] However, traditional pore-forming agents are insufficient to further meet the high requirements of high-performance SOFCs for anode structure and conductivity in terms of improving anode porosity and electrochemical performance. Meanwhile, a large amount of valuable rare earth elements in rare earth mine wastewater cannot be effectively recovered and utilized, resulting not only in resource waste but also a serious 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, in order to achieve the dual goals of improving material performance and addressing environmental issues. Summary of the Invention

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

[0006] To achieve the above objectives, the main technical solutions adopted by the present invention include:

[0007] A method for preparing an SOFC anode support includes the following steps:

[0008] Step S1: Place NiO, YSZ and PVB into a ball mill jar, add anhydrous ethanol, and ball mill at 260-280 r / min for 10 h;

[0009] Step S2: After drying the obtained mixed sample in an oven at 60-70℃, put it back into a ball mill jar, add the composite pore-forming agent, and ball mill at 260-280 r / min for 2 h.

[0010] Step S3: Take 0.3-0.5 parts of the ball-milled powder, put it into a 13mm diameter mold and prepare it under a pressure of 6Mpa for 10-30 seconds to obtain a 13mm diameter blank. Then, calcine it in a muffle furnace at a high temperature of 1100-1200℃ for 2-3 hours to obtain the SOFC anode support.

[0011] In a further embodiment, in step S2, the composite pore-forming agent is composed of a mixture of microbial protein containing rare earth elements and a traditional pore-forming agent in a mass percentage ratio of 70%–90%: 10%–30%.

[0012] In a further embodiment, the conventional pore-forming agent includes soluble starch or carbon powder; the soluble starch includes corn starch and potato starch.

[0013] In a further embodiment, the rare earth-containing microbial protein is in powder form with a particle size of approximately 1-10 μm.

[0014] In a further embodiment, the mass ratio of NiO, YSZ to the composite pore-forming agent is 40-60:40-60:20-25.

[0015] In a further embodiment, the mass ratio of NiO, YSZ to the composite pore-forming agent is 40:60:20.

[0016] 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.

[0017] 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.

[0018] In a further embodiment, the rare earth element-containing microbial protein is prepared through the following steps:

[0019] Step 1: Add rare earth mine wastewater to the basic culture medium to obtain the first mixture;

[0020] Step 2: Inoculate the activated hydroxide bacteria solution into the first mixture to obtain the second mixture;

[0021] Step 3: Transfer the second mixture to a reactor, introduce mixed gas, and then culture it. The mixed gas contains CO2, O2, and H2, thereby using the hydroxide bacteria to ferment and obtain microbial protein containing rare earth elements.

[0022] In step 2, the hydroxide bacteria include the following relative abundances of bacteria: Hydrogenophaga 30%-70%; and Xanthobacter 70%-30%; the volume ratio of the activated hydroxide bacteria solution, the basic culture medium and the rare earth mine wastewater in the second mixture is (15%-25%): (25%-35%): (45%-55%).

[0023] In the second mixture, the volume ratio of the activated hydroxide bacteria solution, the basic culture medium, and the rare earth mine wastewater in step 2 is 20%:30%:50%.

[0024] 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 purging frequency of the mixed gas is 10-14 h, and the purging time is 2-5 min.

[0025] The hydraulic residence time of the second mixture described in step 3 in the reactor is 5 days.

[0026] During the cultivation process described in step 3, aeration is performed every 12-36 hours, with each aeration treatment lasting 2-3 minutes.

[0027] The culture temperature of the reactor described in step 3 is 25-35℃.

[0028] In step 3, the step of obtaining microbial protein is as follows: centrifuge the microbial community in the fermentation system in the reactor at 8000-12000 rpm for 5-15 min, discard the supernatant, and keep the precipitate; wash the precipitate with deionized water and centrifuge again at 8000-12000 rpm for 5-15 min, repeat the washing and centrifugation 1-3 times to obtain the washed precipitate; place the washed precipitate in an oven at 100-110℃ and bake for 20-28 h to finally obtain microbial protein.

[0029] The wastewater from rare earth mines is ion-type rare earth mine wastewater.

[0030] This invention provides the application of the above-described SOFC anode support in SOFC.

[0031] Compared with the prior art, the beneficial effects of this application are:

[0032] This invention provides a method for preparing an SOFC anode support. NiO and YSZ are used as matrix materials, PVB as a binder, and anhydrous ethanol as the ball milling medium. The materials are ball-milled for an extended period at a specific rotation speed to achieve uniform mixing. After drying, a composite pore-forming agent is introduced, followed by ball milling again. The resulting anode support is then pressed and calcined at high temperature to obtain a structurally stable and high-performance anode support. The introduction of the composite pore-forming agent is a key factor in improving anode performance. This agent is composed of traditional pore-forming agents (such as soluble starch or carbon powder) and microbial proteins containing rare earth elements. It not only retains the ability of traditional pore-forming agents to form porous structures during high-temperature calcination but also further optimizes the microstructure and catalytic activity of the anode material through the rare earth elements enriched in the microbial proteins. The complex formed by rare earth elements and microbial proteins helps enhance the conductivity of the anode and the diffusion efficiency of reactant gases, thereby significantly improving the porosity and peak power density of the battery, resulting in better battery performance. The method of this invention is controllable and easy to operate. The anode support obtained has excellent pore structure and electrochemical performance, and is suitable for large-scale application of high-performance solid oxide fuel cells.

[0033] Rare earth element-containing microbial proteins are obtained through wastewater treatment. Using rare earth mine wastewater and an additional basic culture medium as the growth medium for hydroxide-containing bacteria, rare earth element cations can replace potassium and sodium ions within the bacteria, allowing them to enter the bacteria and enrich the rare earth elements in the wastewater, thus yielding rare earth element-containing microbial proteins. This not only recovers rare earth elements from mine wastewater, alleviating downstream treatment pressure, but also utilizes the recovered rare earth elements in batteries through bio-fermentation, generating economic benefits and achieving coordinated economic and ecological development. Detailed Implementation

[0034] To facilitate understanding of the present invention, specific embodiments are provided below to further illustrate the technical solutions described herein, but the present invention is not limited thereto. All technologies implemented based on the above-described content of the present invention are covered within the scope of protection intended by the present invention. Unless otherwise stated, the raw materials and reagents used in the embodiments are commercially available products. Reagents, instruments, or operating procedures not described herein are all matters that can be conventionally determined by those skilled in the art.

[0035] These embodiments are provided to make the application thorough and complete, and to fully express the scope of the application to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of steps, material composition, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0036] It should be noted that, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0037] All terms used in this application have the same meaning as understood by one of ordinary skill in the art to which this application pertains, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant art, and not as idealized or highly formalized, unless expressly defined herein.

[0038] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0039] To more clearly illustrate this application, the following description, in conjunction with preferred embodiments, further clarifies the application. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive and should not be construed as limiting the scope of protection of this invention.

[0040] In this application, unless otherwise stated, the number of parts and percentages refer to parts by weight and percentage by weight.

[0041] In this application, YSZ is 8 mol% Y2O3-doped ZrO2.

[0042] In this application, the term "hydrogen-oxidizing bacteria" refers to microorganisms that can use hydrogen as an electron donor to reduce carbon dioxide into organic matter.

[0043] In this invention, the term "purging" refers to the process of introducing gas into the fermenter during microbial fermentation to purge out the gas inside the fermenter from the previous day, and then introducing gas prepared in a certain proportion to ensure that the gas inside the fermenter reacts in the same proportion every day.

[0044] In this application, the term "fermentation system" refers to a fermentation system composed of microorganisms and culture medium cultivated in a reactor, and in form, it refers to a mixture of microorganisms and mixed biological culture medium.

[0045] In this application, the term "microbial protein" in the phrase "microbial protein containing rare earth elements" refers to a bacterial cell cytoplasm mass produced by bacteria, fungi, yeast, or algae under suitable growth conditions, consisting of a mixture of proteins, carbohydrates, nucleic acids, fats, non-protein nitrogenous compounds, vitamins, and inorganic compounds.

[0046] 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 fuel into electrical and thermal energy.

[0047] In this application, the term "anode support" refers to the basic functional component of a solid oxide fuel cell.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] Example 1

[0073] (1) Prepare the basic culture medium and add ion-type rare earth mine wastewater.

[0074] The basal culture medium is formulated with the following substances per liter of solution: glucose 6.4g, ammonium chloride 1.0g, disodium hydrogen phosphate 2.9g, calcium chloride 0.01g, magnesium sulfate 0.5g, sodium bicarbonate 0.5g, potassium dihydrogen phosphate 2.3g, ferric ammonium citrate 0.05g, zinc sulfate 0.2mg, cobalt chloride 0.4mg, boric acid 0.6mg, sodium molybdate 0.06mg, nickel chloride 0.04mg, copper sulfate 0.02mg, and manganese chloride 0.06mg.

[0075] Ionic rare earth mine wastewater was added to a reactor containing basic culture medium to obtain the first mixture, which was then sterilized at 121°C for 20 min.

[0076] (2) First, the hydroxide bacteria were activated. The activation method was to use a 500 mL blue-mouth bottle with a working volume of 150 mL and a headspace volume of 450 mL. The inoculum was 20% of the acclimated hydroxide bacteria culture. The culture medium used was the basal culture medium from step (1). The ammonia nitrogen concentration was adjusted to 1000 mg N / L. In order to make the hydroxide bacteria population recover its activity faster, 24.75 g / L of glucose was added to adjust the carbon-nitrogen ratio to 9. The headspace was purged for 3 min with a mixture of CO2:O2:H2=15:25:60 and a pressure of 1 bar. After completion, the bottle was sealed. The headspace was purged once every 12 h. The pH of the culture medium was adjusted to 7.0 daily with 2 mol / L HCl and 2 mol / L NaOH. The temperature was fixed at 28℃ and the rotation speed was set at 160 rpm. The activated hydroxide bacteria solution was inoculated into the first mixture to obtain the second mixture, which consisted of 20% by volume of the activated hydroxide bacteria solution, 30% by volume of the basal culture medium, and 50% by volume of the ion-type rare earth mine wastewater.

[0077] The second mixture was then incubated in a constant temperature shaking incubator at 28°C for 5 days. The pH of the second mixture was 7.0±0.2, and the shaking rate of the constant temperature shaking incubator was 160 rpm.

[0078] (3) Transfer the second mixture from step (2) to the reactor, introduce mixed gas for cultivation at a temperature of 28°C. The mixed gas contains CO2, O2, and H2; the volume ratio of CO2:O2:H2 = 15:25:60. The purging frequency of the mixed gas is 12 h, and the purging time for each purge is 3 min. In the reactor, the volume of the second mixture: headspace volume = 150:450.

[0079] (4) The reactor receives and discharges water daily to aerate the reaction system;

[0080] In step (4), the reactor has a daily inflow and outflow of 50 mL of water, where “inflow” means adding 50 mL of basic culture medium at a time and “outflow” means discharging 50 mL of fermentation broth at a time. The hydraulic retention time is 5 days.

[0081] In step (4), the fermentation system in the reactor is aerated once every 24 hours, and the aeration time is 3 minutes each time.

[0082] (5) After 15 days of cultivation, the microbial community in the fermentation system in the reactor was centrifuged at 8000 rpm for 10 min, the supernatant was discarded, and the precipitate was retained. The precipitate was washed with deionized water and centrifuged again at 10000 rpm for 10 min. The washing and centrifugation were repeated 3 times to obtain the washed precipitate. The washed precipitate was placed in an oven at 100℃ and baked for 25 h to obtain microbial protein containing rare earth elements. The changes in rare earth element concentration and recovery rate in Example 1 are shown in Table 1.

[0083] Table 1: Changes in concentration and recovery rate of key rare earth elements in Example 1

[0084]

[0085] The rare earth element-containing microbial protein contains 0.05% rare earth elements by weight and 66% microbial protein by weight. The microbial protein includes 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.

[0086] (6) 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.

[0087] (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 jar, 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 dried in a 60 ℃ oven and then placed back into the ball mill jar. 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 placed in a 13 mm diameter mold and anode support is prepared under a pressure of 6 MPa to obtain a 13 mm diameter blank. The blank is then calcined at 1100 ℃ for 2 h in a muffle furnace to finally obtain the anode support.

[0088] (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 the sealing material, silver paste and silver wire are used to collect the current, and the performance of the cell is tested at 750°C.

[0089] In step (8), a DC electronic load and an electrochemical workstation are used to perform battery testing.

[0090] Electrochemical performance was tested, and morphology analysis was performed using field emission scanning electron microscopy.

[0091] Table 2 shows the porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained from the final tests in this embodiment. The microstructure reveals a uniform porous structure. Table 2 shows that the anode support prepared by mixing soluble starch and protein powder in a 100:0 ratio has a porosity of 23.58%. Furthermore, the peak power density of the battery was measured to be 0.92 W / cm³. 2 .

[0092] Table 2: Final anode support porosity and peak power density of the battery in Example 1

[0093]

[0094] Example 2

[0095] Example 1 is repeated, except that: in step (6), soluble starch and the rare earth element-containing microbial protein obtained in step (5) are mixed in a ratio of 90:10 to prepare a composite pore-forming agent, and the rare earth element-containing microbial protein has a particle size of 10 μm.

[0096] Table 3 shows the porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained from the final tests in this embodiment. The microstructure reveals a uniform porous structure. Table 3 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 90:10 ratio) has a porosity of 25.77%. Furthermore, the peak power density of the battery was measured to be 1.06 W / cm³. 2 .

[0097] Table 3: Final anode support porosity and peak power density of the battery in Example 2

[0098]

[0099] Example 3

[0100] Example 1 is repeated, except that: in step (6), soluble starch and the rare earth element-containing microbial protein obtained in step (5) are mixed in a ratio of 80:20 to prepare a composite pore-forming agent, and the rare earth element-containing microbial protein has a particle size of 1 μm.

[0101] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 4. The microstructure reveals a uniform porous structure. Table 4 shows that the anode support prepared with a composite pore-forming agent (80:20 ratio of soluble starch and protein powder) has a porosity of 28.37%. Furthermore, the tested peak power density of the battery is 1.19 W / cm³. 2 .

[0102] Table 4: Final anode support porosity and peak power density of the battery in Example 3

[0103]

[0104] Example 4

[0105] Example 1 was repeated, except that: in step (6), 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 rare earth element-containing microbial protein had a particle size of 5 μm.

[0106] Table 5 shows the porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment. The microstructure reveals a uniform porous structure. Table 5 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 70:30 ratio) has a porosity of 30.31%. The tested peak power density of the battery is 1.26 W / cm³.2 .

[0107] Table 5: Final anode support porosity and peak power density of the battery in Example 4

[0108]

[0109] Furthermore, through cross-testing (i.e., comparative experiments were conducted using rare earth element-containing microbial proteins with particle sizes of 1 μm, 3 μm, 5 μm, 7 μm, and 10 μm, respectively, based on this embodiment), it was found that the sample with a particle size of 5 μm exhibited the best performance. Therefore, in subsequent embodiments and comparative examples, rare earth element-containing microbial proteins with a particle size of 5 μm were uniformly used.

[0110] Experimental data at 1 μm: porosity 29.33%, peak power density 1.09 (W / cm³). 2) ;

[0111] Experimental data at 3μm: porosity (%) 30.02%, peak power density 1.18 (W / cm³). 2) ;

[0112] Experimental data for 7μm: porosity (%) 29.8-7.31%, peak power density 1.16 (W / cm³). 2) ;

[0113] Experimental data at 10 μm: Porosity (%) 29.66%, peak power density 1.13 (W / cm³) 2) .

[0114] When the particle size is too small, although the specific surface area is large, which is beneficial for the dispersion and catalytic effect of rare earth elements, the particles are easily blocked or agglomerated during high-temperature calcination due to their small size. This prevents the effective formation of some pores, resulting in relatively low porosity and electrochemical performance. When the particle size is too large, although the gaps between particles are large, their uneven distribution in the material easily leads to the formation of local macropores, which disrupts the uniformity of the overall pore structure. This reduces the effective specific surface area and the continuity of the conductive network, ultimately causing a decline in battery performance.

[0115] 5μm rare earth element-containing microbial proteins can achieve a good balance between pore-forming effect, rare earth element release and distribution, and microstructure regulation, making them an ideal choice for preparing high-performance SOFC anode supports.

[0116] Example 5

[0117] Repeat Example 1, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) are mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0118] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 6. The microstructure reveals a uniform porous structure. Table 6 shows that the anode support prepared by mixing carbon powder and protein powder in a 100:0 ratio has a porosity of 21.68%. Furthermore, the peak power density of the battery was measured to be 0.87 W / cm³. 2 .

[0119] Table 6: Final anode support porosity and peak power density of the battery in Example 5

[0120]

[0121] Example 6

[0122] Repeat Example 1, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0123] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 7. The microstructure reveals a uniform porous structure. Table 7 shows that the anode support prepared by mixing carbon powder and protein powder in a 70:30 ratio has a porosity of 27.15%. Furthermore, the tested peak power density of the battery is 1.14 W / cm³. 2 .

[0124] Table 7: Final anode support porosity and battery peak power density in Example 6

[0125]

[0126] Example 7

[0127] The changes in rare earth element concentration and recovery rate in Example 1 and Example 7 are shown in Table 8. The only difference is that in step (7), the mass ratios 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.

[0128] NiO, YSZ, and PVB were placed in a ball mill jar, and an appropriate amount of anhydrous ethanol was added. The mixture was ball-milled at 260 r / min for 10 h. The resulting sample was dried in a 60 °C oven and then placed back into the ball mill jar. 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 placed in a 13 mm diameter mold and subjected to a pressure of 6 MPa to prepare an anode support. A 13 mm diameter blank was obtained and 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.

[0129] Table 8: Changes in concentration and recovery rate of key rare earth elements in Example 7

[0130]

[0131] The rare earth element-containing microbial protein contains 0.08% rare earth elements by weight and 62% microbial protein by weight. The microbial protein includes 18 amino acids, of which the essential amino acids lysine, methionine, phenylalanine, isoleucine, leucine, threonine, valine, and tryptophan account for 12%, 4%, 4%, 9%, 5%, 7%, and 6% by weight, respectively. The remaining 11 non-essential amino acids account for 53% by weight.

[0132] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 9. The microstructure reveals a uniform porous structure. Table 9 shows that the anode support prepared by mixing soluble starch and protein powder in a 100:0 ratio has a porosity of 26.33%. Furthermore, the peak power density of the battery was measured to be 1.09 W / cm³. 2 .

[0133] Table 9: Final anode support porosity and peak power density of the battery in Example 7

[0134]

[0135] Example 8

[0136] Example 7 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0137] Table 10 shows the porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment. The microstructure reveals a uniform porous structure. Table 10 shows that the anode support prepared by mixing soluble starch and protein powder in a 90:10 ratio has a porosity of 29.46%. Furthermore, the tested peak power density of the battery is 1.21 W / cm³. 2 .

[0138] Table 10: Final anode support porosity and battery peak power density in Example 8

[0139]

[0140] Example 9

[0141] Example 7 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0142] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 11. The microstructure reveals a uniform porous structure. Table 11 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in an 80:20 ratio) has a porosity of 33.40%. Furthermore, the tested peak power density of the battery is 1.35 W / cm³. 2 .

[0143] Table 11: Final anode support porosity and battery peak power density in Example 9

[0144]

[0145] Example 10

[0146] Example 7 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0147] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 12. The microstructure reveals a uniform porous structure. Table 12 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 70:30 ratio) has a porosity of 35.59%. Furthermore, the tested peak power density of the battery is 1.42 W / cm³. 2 .

[0148] Table 12: Final anode support porosity and peak power density of the battery in Example 10

[0149]

[0150] Example 11

[0151] Example 7 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 60:40 to prepare a composite pore-forming agent.

[0152] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 13. The microstructure reveals a uniform porous structure. Table 13 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 60:40 ratio) has a porosity of 30.25%. Furthermore, the tested peak power density of the battery is 1.23 W / cm³. 2 .

[0153] Table 13: Final anode support porosity and peak power density of the battery in Example 11

[0154]

[0155] Example 12

[0156] Example 7 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 50:50 to prepare a composite pore-forming agent.

[0157] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 14. The microstructure reveals a uniform porous structure. Table 14 shows that the anode support prepared by mixing soluble starch and protein powder in a 50:50 ratio has a porosity of 27.89%. Furthermore, the tested peak power density of the battery is 1.16 W / cm³. 2 .

[0158] Table 14: Final anode support porosity and peak power density of the battery in Example 12

[0159]

[0160] Example 13

[0161] Example 7 is repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) are mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0162] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 15. The microstructure reveals a uniform porous structure. Table 15 shows that the anode support prepared by mixing carbon powder and protein powder in a 100:0 ratio has a porosity of 25.38%. Furthermore, the peak power density of the battery was measured to be 1.05 W / cm³. 2 .

[0163] Table 15: Final anode support porosity and peak power density of the battery in Example 13

[0164]

[0165] Example 14

[0166] Example 7 was repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0167] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 16. The microstructure reveals a uniform porous structure. Table 16 shows that the anode support prepared by mixing carbon powder and protein powder in a 90:10 ratio has a porosity of 27.41%. Furthermore, the tested peak power density of the battery is 1.15 W / cm³. 2 .

[0168] Table 16: Final anode support porosity and peak power density of the battery in Example 14

[0169]

[0170] Example 15

[0171] Example 7 was repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0172] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 17. The microstructure reveals a uniform porous structure. Table 17 shows that the anode support prepared by mixing carbon powder and protein powder in an 80:20 ratio has a porosity of 29.18%. Furthermore, the peak power density of the battery was measured to be 1.20 W / cm³. 2 .

[0173] Table 17: Final anode support porosity and peak power density of the battery in Example 15

[0174]

[0175] Example 16

[0176] Example 7 was repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0177] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 18. The microstructure reveals a uniform porous structure. Table 18 shows that the anode support prepared by mixing carbon powder and protein powder in a 70:30 ratio has a porosity of 32.96%. Furthermore, the peak power density of the battery was measured to be 1.33 W / cm³. 2 .

[0178] Table 18: Final anode support porosity and peak power density of the battery in Example 16

[0179]

[0180] Example 17

[0181] Example 7 is repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) are mixed in a ratio of 60:40 to prepare a composite pore-forming agent.

[0182] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 19. The microstructure reveals a uniform porous structure. Table 19 shows that the anode support prepared by mixing carbon powder and protein powder in a 60:40 ratio has a porosity of 28.20%. Furthermore, the tested peak power density of the battery is 1.18 W / cm³. 2 .

[0183] Table 19: Final anode support porosity and peak power density of the battery in Example 17

[0184]

[0185] Example 18

[0186] Example 7 is repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) are mixed in a ratio of 50:50 to prepare a composite pore-forming agent.

[0187] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 20. The microstructure reveals a uniform porous structure. Table 20 shows that the anode support prepared by mixing carbon powder and protein powder in a 50:50 ratio has a porosity of 26.95%. Furthermore, the tested peak power density of the battery is 1.12 W / cm³. 2 .

[0188] Table 20: Final anode support porosity and peak power density of the battery in Example 18

[0189]

[0190] Example 19

[0191] Repeat Example 1, except that in step (7), the ratio of NiO:YSZ:composite pore-forming agent = 60:40:20, NiO:YSZ:PVB = 60:40:10, and PVB:anhydrous ethanol:composite pore-forming agent = 10:75:20. NiO, YSZ and PVB were placed in a ball mill jar, 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 dried in an oven and then placed back into the ball mill jar. 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 placed in a 13 mm diameter mold and subjected to a pressure of 6 MPa to prepare an anode support. A 13 mm diameter blank was obtained and calcined in a muffle furnace at 1100 °C for 2 h to finally obtain the anode support.

[0192] The changes in rare earth element concentration and recovery rate in Example 19 are shown in Table 21.

[0193] Table 21: Changes in concentration and recovery rate of key rare earth elements in Example 19

[0194]

[0195] The rare earth element-containing microbial protein contains 0.04% rare earth elements by weight and 64% microbial protein by weight. The microbial protein includes 18 amino acids, of which the essential amino acids lysine, methionine, phenylalanine, isoleucine, leucine, threonine, valine, and tryptophan account for 15%, 6%, 4%, 8%, 6%, 5%, and 6% by weight, respectively. The remaining 11 non-essential amino acids account for 50% by weight.

[0196] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 22. The microstructure reveals a uniform porous structure. Table 22 shows that the anode support prepared by mixing soluble starch and protein powder in a 100:0 ratio has a porosity of 21.12%. Furthermore, the peak power density of the battery was measured to be 0.86 W / cm³. 2 .

[0197] Table 22: Final anode support porosity and peak power density of the battery in Example 19

[0198]

[0199] Example 20

[0200] Example 19 was repeated, except that in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 90:10 to prepare a composite pore-forming agent.

[0201] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 23. The microstructure reveals a uniform porous structure. Table 23 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 90:10 ratio) has a porosity of 23.03%. Furthermore, the tested peak power density of the battery is 0.91 W / cm³. 2 .

[0202] Table 23: Final anode support porosity and peak power density of the battery in Example 20

[0203]

[0204] Example 21

[0205] Example 19 was repeated, except that: in step (6), soluble starch and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 80:20 to prepare a composite pore-forming agent.

[0206] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 24. The microstructure reveals a uniform porous structure. Table 24 shows that the anode support prepared with a composite pore-forming agent (80:20 ratio of soluble starch and protein powder) has a porosity of 24.92%. Furthermore, the tested peak power density of the battery is 0.99 W / cm³. 2 .

[0207] Table 24: Final anode support porosity and peak power density of the battery in Example 21

[0208]

[0209] Example 22

[0210] Example 19 was repeated, except that in step (6), soluble starch and rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0211] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 25. The microstructure reveals a uniform porous structure. Table 25 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 70:30 ratio) has a porosity of 27.64%. Furthermore, the tested peak power density of the battery is 1.16 W / cm³. 2 .

[0212] Table 25: Final anode support porosity and peak power density of the battery in Example 22

[0213]

[0214] Example 23

[0215] Example 19 was repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 100:0 to prepare a composite pore-forming agent.

[0216] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 26. The microstructure reveals a uniform porous structure. Table 26 shows that the anode support prepared by mixing carbon powder and protein powder in a 100:0 ratio has a porosity of 20.45%. Furthermore, the tested peak power density of the battery is 0.83 W / cm³. 2 .

[0217] Table 26: Final anode support porosity and peak power density of the battery in Example 23

[0218]

[0219] Example 24

[0220] Example 19 was repeated, except that in step (6), the carbon powder and the rare earth-containing microbial protein obtained in step (5) were mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0221] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 27. The microstructure reveals a uniform porous structure. Table 27 shows that the anode support prepared by mixing carbon powder and protein powder in a 70:30 ratio has a porosity of 26.38%. Furthermore, the tested peak power density of the battery is 1.11 W / cm³. 2 .

[0222] Table 27: Final anode support porosity and peak power density of the battery in Example 24

[0223]

[0224] The results from Examples 1-24 show that as the content of rare earth element-containing protein in the composite pore-forming agent prepared by mixing soluble starch with rare earth element-containing microbial protein increases, both porosity and peak power density gradually increase. This indicates that the addition of rare earth element-containing microbial protein has a significant effect on the battery performance of SOFCs, and the composite pore-forming agent prepared by mixing soluble starch and rare earth element-containing microbial protein at a ratio of 70:30 exhibits the best effect. Comparing the results of Examples 1-6, 7-18, and 19-24, the optimal ratio of NiO:YSZ:composite pore-forming agent (40:60:20) yields the best pore-forming agent effect and SOFC battery performance. However, when the ratio of NiO:YSZ:composite pore-forming agent is 60:40:20, both the pore-forming agent effect and SOFC battery performance decrease.

[0225] The results of Examples 5, 13, and 23 show that using carbon powder alone as a pore-forming agent resulted in unsatisfactory pore-forming effects and battery performance. However, comparing the results of Examples 6, 14-18, and 24, the addition of rare-earth-element-containing microbial protein powder mixed with carbon powder to prepare a composite pore-forming agent significantly improved both porosity and peak power density. This further demonstrates that the addition of rare-earth-element-containing microbial protein has a good effect on the performance of SOFC batteries. The examples also show that composite pore-forming agents prepared by mixing rare-earth-element-containing microbial protein with other traditional pore-forming agents also have good effects.

[0226] To clarify whether the effect of the composite pore-forming agent on the improvement of SOFC anode performance is caused by the rare earth element itself or by the formation of a complex between the rare earth element and microbial protein, this invention further sets up Comparative Example 1 and Comparative Example 2 for comparative verification.

[0227] Comparative Example 1

[0228] Example 10 was repeated, except that the rare earth element-containing microbial protein in the original Example 10 was replaced with an equal amount of a mixture A of key rare earth elements. "Equal amount" refers to an equal amount of key rare earth elements.

[0229] In step (6), soluble starch and the above mixture A are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0230] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 28. The microstructure reveals a non-uniform porous structure. Table 28 shows that the anode support prepared with a composite pore-forming agent (a mixture of soluble starch and protein powder in a 70:30 ratio) has a porosity of 30.17%. Furthermore, the peak power density of the battery was measured to be 1.22 W / cm³. 2 .

[0231] Table 28: Final anode support porosity and peak power density of the battery in Comparative Example 1

[0232]

[0233] Comparative Example 2

[0234] Example 10 was repeated, except that the rare earth element-containing microbial protein in the original Example 10 was replaced with an equal amount of a mixture A of key rare earth elements. "Equal amount" refers to the equal amount of each rare earth element.

[0235] 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.

[0236] The porosity of the anode support and the peak power density of the single cell operating at 750°C, obtained in this embodiment, are shown in Table 29. The microstructure reveals a non-uniform porous structure. Table 29 shows that the anode support prepared by mixing carbon powder and protein powder in a 70:30 ratio has a porosity of 28.24%. Furthermore, the tested peak power density of the battery is 1.18 W / cm³. 2 .

[0237] Table 29: Final anode support porosity and peak power density of the battery in Comparative Example 2

[0238]

[0239] Comparative Example 3

[0240] Example 10 was repeated, except that the rare earth element-containing microbial protein in the original Example 10 was replaced with a mixture B formed from equal amounts of key rare earth element oxides. "Equal amounts" refers to equal amounts of each rare earth element.

[0241] In step (6), soluble starch and the above mixture B are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0242] Microscopic analysis revealed a non-uniform porous structure in the battery. The porosity of the anode support prepared with the composite pore-forming agent was 31.22%. Furthermore, testing showed that the battery's peak power density was 1.23 W / cm³. 2 .

[0243] Comparative Example 4

[0244] Example 10 was repeated, except that the rare earth element-containing microbial protein in the original Example 10 was replaced with a mixture C formed from equal amounts of rare earth element oxides. "Equal amounts" refers to equal amounts of each rare earth element.

[0245] 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.

[0246] Microscopic analysis revealed a non-uniform porous structure in the battery. The porosity of the anode support prepared with the composite pore-forming agent was 29.41%. Furthermore, testing showed that the battery's peak power density was 1.20 W / cm³. 2 .

[0247] Comparative Example 5

[0248] Example 10 was repeated, except that an equal amount of rare earth element mixture D in sulfate form was used instead of the rare earth element-containing microbial protein in the original Example 10. "Equal amount" means that the rare earth element content in the sulfate form is equal to the rare earth element content in the rare earth element-containing microbial protein.

[0249] In step (6), soluble starch and the above mixture D are mixed in a ratio of 70:30 to prepare a composite pore-forming agent.

[0250] Microscopic analysis revealed a non-uniform porous structure in the battery. The porosity of the anode support prepared with the composite pore-forming agent was 31.45%. Furthermore, testing showed that the battery's peak power density was 1.29 W / cm³. 2 .

[0251] Comparative Example 6

[0252] The only difference is that the key rare earth element in the form of sulfate and mixture E replaces the rare earth element-containing microbial protein in the original Example 10. "Equal amount" means that the rare earth element content in the sulfate form is equal to the key rare earth element content in the rare earth element-containing microbial protein.

[0253] 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.

[0254] Microscopic analysis revealed a non-uniform porous structure in the battery. The porosity of the anode support prepared with the composite pore-forming agent was 30.09%. Furthermore, testing showed that the battery's peak power density was 1.19 W / cm³. 2 .

[0255] Comparing the experimental results of Example 10 with those of Comparative Examples 1-6, it is evident that the microbial protein containing rare earth elements significantly outperforms the rare earth elements alone in improving the performance of SOFC anodes. This is likely because the microbial protein not only effectively enriches the rare earth elements as a carrier but also forms a stable complex structure between the protein and the rare earth elements. This complex can release the rare earth elements more uniformly during high-temperature sintering and form active sites around them, thereby optimizing the anode's microstructure and enhancing conductivity and catalytic activity. In contrast, simply adding rare earth elements makes it difficult to achieve such a uniform distribution, easily leading to agglomeration or excessively high local concentrations, resulting in uneven pore structure and decreased performance. Therefore, the complex formed by the microbial protein containing rare earth elements is key to improving anode performance.

[0256] To clarify the effect of the ratio of NiO:YSZ:composite pore-forming agent:PVB:anhydrous ethanol on the improvement of SOFC anode performance by composite pore-forming agent, comparative examples 7-10 were set up.

[0257] Comparative Example 7

[0258] Example 10 was repeated, except that the mass ratio of NiO, YSZ and composite pore-forming agent was 40:60:15.

[0259] In this embodiment, the porosity of the anode support and the peak power density of the single cell operating at 750°C were 31.26 and 1.28, respectively, as finally tested.

[0260] Comparative Example 8

[0261] Example 10 was repeated, except that the mass ratio of NiO, YSZ and the composite pore-forming agent was 40:60:30.

[0262] In this embodiment, the porosity of the anode support and the peak power density of the single cell operating at 750°C were 32.18 and 1.31, respectively, as finally tested.

[0263] Comparative Example 9

[0264] Example 10 was repeated, with the mass ratio of NiO, YSZ and composite pore-forming agent being 40:60:20. The only difference was that: NiO:YSZ:PVB = 40:60:30, and PVB:anhydrous ethanol:composite pore-forming agent = 30:75:20.

[0265] In this embodiment, the porosity of the anode support and the peak power density of the single cell operating at 750°C were finally tested and obtained as 33.89 and 1.38, respectively.

[0266] Comparative Example 10

[0267] Example 10 was repeated, with the mass ratio of NiO, YSZ and composite pore-forming agent being 40:60:20. The only difference was that: NiO:YSZ:PVB = 40:60:10, and PVB:anhydrous ethanol:composite pore-forming agent = 10:50:20.

[0268] In this embodiment, the porosity of the anode support and the peak power density of the single cell operating at 750°C were 32.87 and 1.32, respectively, as finally tested.

[0269] Based on the experimental results of Comparative Examples 7 to 10, the ratio of NiO, YSZ, composite pore-forming agent, PVB, and anhydrous ethanol has a certain impact on the performance of SOFC anode supports. When the ratio of NiO:YSZ:composite pore-forming agent deviates from the optimized range (e.g., 40:60:15 in Comparative Example 7 or 40:60:30 in Comparative Example 8), the porosity and peak power density of the anode both decrease. This indicates that too low a pore-forming agent content is not conducive to the formation of a sufficient porous structure, while too high a content disrupts the continuity of the matrix material and the conductive network, thus limiting performance improvement.

[0270] Furthermore, the ratio of PVB binder to anhydrous ethanol ball milling media also has a significant impact. Based on a NiO:YSZ:composite pore-forming agent ratio of 40:60:20, Comparative Example 9 (with PVB content increased to 30%) exhibited relatively better performance (porosity 33.89%, power density 1.38 W / cm³). 2 This indicates that appropriately increasing the binder helps to achieve uniform powder dispersion and preform formation. However, if the proportion of anhydrous ethanol is too low (such as reducing the ethanol content to 50% in Comparative Example 10), it will affect the ball milling effect and component uniformity, thereby reducing the final performance.

[0271] In conclusion, only with the optimized ratios of NiO:YSZ:composite pore-forming agent = 40:60:20 and PVB:anhydrous ethanol:composite pore-forming agent = 10:75:20 can the uniformity of material structure, the rationality of pore distribution, and the best balance of electrochemical performance be achieved, thereby obtaining the optimal battery performance.

[0272] Therefore, the technology of preparing composite pore-forming agents using microbial proteins containing rare earth elements obtained by microbial fermentation is entirely feasible, and its application in SOFC has a very good effect on improving battery performance.

[0273] The various embodiments of the present invention have now been described in detail. To avoid obscuring the concept of the invention, some details known in the art have not been described. Those skilled in the art can fully understand how to implement the technical solutions of this invention based on the above description.

[0274] While specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the invention. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of the invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any manner.

Claims

1. A method for preparing an SOFC anode support, characterized in that, Includes the following steps: Step S1: Place NiO, YSZ and PVB into a ball mill jar, add anhydrous ethanol, and ball mill at 260-280 r / min for 10 h; Step S2: After drying the obtained mixed sample in an oven, put it back into a ball mill jar, add the composite pore-forming agent, and ball mill 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 13mm diameter mold and prepare it under a pressure of 6Mpa for 30-60 seconds to obtain a 13mm diameter blank. Then, calcine it in a muffle furnace at a high temperature of 1100-1200℃ for 2-3 hours to obtain the SOFC anode support. In step S2, the composite pore-forming agent is composed of a mixture of microbial protein containing rare earth elements and a traditional pore-forming agent in a mass percentage ratio of 70%–90%: 10%–30%. The mass ratio of NiO, YSZ and composite pore-forming agent is 40-60:40-60:20-25; The mass ratio of NiO, YSZ and PVB is 40-60:40-60:10-15; The mass ratio of PVB: anhydrous ethanol: composite pore-forming agent is 10:75:

20.

2. The method for preparing the SOFC anode support according to claim 1, characterized in that, The conventional pore-forming agents include soluble starch or carbon powder.

3. The method for preparing the SOFC anode support according to claim 2, characterized in that, The rare earth element-containing microbial protein is in powder form with a particle size of 1-10 μm.

4. The method for preparing the SOFC anode support according to claim 1, characterized in that, The mass ratio of NiO, YSZ to the composite pore-forming agent is 40:60:

20.

5. The method for preparing the SOFC anode support according to claim 1, characterized in that, The rare earth element-containing microbial protein is prepared through the following steps: Step 1: Add rare earth mine wastewater to the basic culture medium to obtain the first mixture; Step 2: Inoculate the activated hydroxide bacteria solution into the first mixture to obtain the second mixture; Step 3: Transfer the second mixture to a reactor, introduce mixed gas, and then culture it. The mixed gas contains CO2, O2, and H2, thereby using the hydroxide bacteria to ferment and obtain microbial protein containing rare earth elements. In step 2, the hydroxide bacteria include the following relative abundances of bacteria: Hydrogenophaga 30%-70%; and Xanthobacter 70%-30%; the volume ratio of the activated hydroxide bacteria solution, the basic culture medium and the rare earth mine wastewater in the second mixture is (15%-25%): (25%-35%): (45%-55%).

6. The method for preparing the SOFC anode support according to claim 5, 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 steps to obtain microbial protein are as follows: centrifuge the microbial community in the fermentation system in the reactor at 8000-12000 rpm for 5-15 min, discard the supernatant, and keep the precipitate; wash the precipitate with deionized water and centrifuge again at 8000-12000 rpm for 5-15 min, repeat the washing and centrifugation 1-3 times to obtain the washed precipitate; place the washed precipitate in an oven at 100-110℃ and bake for 20-28 h to finally obtain the microbial protein.

7. The application of the SOFC anode support as described in claim 1 in SOFC.

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