Preparation method of NaInO2-based composite material and electrolyte material for solid oxide fuel cell

Abstract

The present invention discloses a method for preparing a NaInO2-based composite material, comprising: step 1: mixing Na2CO3 and In2O3 and dissolving them in a 95% alcohol solution, stirring at a constant temperature to form a uniform mixed solution; step 2: drying the mixed solution to obtain a precursor powder; step 3: calcining the precursor powder, cooling and grinding it into a fine powder; step 4: washing the fine powder to remove excess Na2CO3; step 5: successively evaporating and grinding the washed powder to finally obtain a dry fine powder; step 6: mixing the dry fine powder with In(OH)3 powder and fully grinding it to obtain a NaInO2+In(OH)3 composite material. The present invention obtains pure phase NaInO2 by adjusting the raw material ratio in the synthesis process, and composites it with In(OH)3 in different proportions. For the first time, the obtained composite material is applied as an electrolyte to the power generation unit of SOFC, thereby further reducing the operating temperature of SOFC and showing good battery power output performance.

Description

Technical Field

[0001] The present invention relates to the technical field of NaInO2-based composite materials, and in particular to a preparation method of a NaInO2-based composite material and an electrolyte material for a solid oxide fuel cell. Background Art

[0002] Solid oxide fuel cells (SOFCs) are highly efficient electrochemical devices that generate electricity by reacting hydrogen or other fuels with oxygen. They offer high energy conversion efficiency and low pollutant emissions. SOFC research not only helps improve energy efficiency but also promotes the transition to clean energy, particularly in the field of distributed power generation. Furthermore, SOFCs have enormous commercial potential, and with advances in materials and manufacturing technologies, their future market prospects are promising. By using clean fuels, SOFCs not only reduce greenhouse gas emissions but also provide flexible and diverse solutions for energy supply.

[0003] With the further development of SOFC technology, low-temperature operation has become a key aspect of its commercialization. To achieve this goal, the development of solid electrolyte materials with high oxygen ion conductivity at medium and low temperatures is crucial. Therefore, research on novel electrolyte materials has become a key topic in the SOFC field in recent years, laying the foundation for improving device performance, reducing costs, and accelerating commercialization.

[0004] NaInO2 is a high-performance material. Its chemical stability, high electrical conductivity, and environmentally friendly properties have shown broad application potential in photocatalysis and formaldehyde adsorption. Due to its unique optical properties, NaInO2 has applications in photocatalysis, particularly in the decomposition of harmful pollutants and water treatment. Furthermore, due to its excellent chemical adsorption properties, it can effectively adsorb and decompose toxic gases such as formaldehyde, showing broad application prospects in air purification. NaInO2 has also attracted widespread attention in the field of environmentally friendly materials. Its non-toxic and renewable properties give it significant application potential in green chemistry and environmental protection technologies. With increasing demands for environmental protection, the versatility of NaInO2 will play a vital role in future new energy sources, environmental governance, and the design of novel catalysts. Although NaInO2 materials hold broad application prospects in photocatalysis and formaldehyde adsorption, their preparation processes are plagued by high-temperature requirements, complex processes, and high costs, which limit their large-scale production and application.

[0005] This paper develops a method for preparing a NaInO2-based composite material. By adjusting the raw material ratios during the synthesis process, pure NaInO2 is obtained. This material is then combined with In(OH)3 in varying proportions to form a composite material. For the first time, this composite material is applied as an electrolyte in a SOFC power generation unit, further reducing the SOFC's operating temperature and demonstrating excellent cell power output performance.

[0006] Therefore, it is very meaningful to widely use NaInO2 in the preparation of electrolyte materials. Summary of the Invention

[0007] In view of this, the present invention provides a method for preparing a NaInO2-based composite material and an electrolyte material for a solid oxide fuel cell, so as to provide an electrolyte material with good low-temperature electrochemical properties.

[0008] In one aspect, the present invention provides a method for preparing a NaInO2-based composite material, comprising:

[0009] Step 1: Mix Na2CO3 and In2O3 and dissolve them in 95% alcohol solution, stirring at a constant temperature to form a uniform mixed solution;

[0010] Step 2: drying the mixed solution to obtain a precursor powder;

[0011] Step 3: After calcining the precursor powder, cooling and grinding into fine powder;

[0012] Step 4: Wash the finely crushed powder to remove excess Na2CO3;

[0013] Step 5: The cleaned powder is evaporated and ground in sequence to obtain a dry fine powder;

[0014] Step 6: Mix the dried fine powder with In(OH)3 powder and grind them thoroughly to obtain NaInO2+In(OH)3 composite material.

[0015] Preferably, the molar ratio of Na2CO3 and In2O3 mixed in step 1 is 2:1.

[0016] Preferably, the constant temperature stirring condition in step 1 is stirring at a constant temperature of 60° C. for 12 hours.

[0017] Preferably, the drying temperature in step 2 is 120°C.

[0018] Preferably, the calcination parameters in step 3 are: calcination at 1000° C. for 5 hours.

[0019] Preferably, the washing of the finely divided powder in step 4 comprises three filtration washings in a vacuum filter, each time using 300 mL of pure water.

[0020] Preferably, in step 6, the mass ratio of the dried fine powder to the In(OH)3 powder is 1:x, wherein x=0.1, 0.2.

[0021] In a second aspect, the present invention further provides an electrolyte material, which comprises the NaInO2-based composite material according to any one of claims 1 to 7.

[0022] Finally, the present invention also provides the application of the electrolyte material to the power generation unit of SOFC.

[0023] The present invention provides a method for preparing a NaInO2-based composite material and an electrolyte material for a solid oxide fuel cell, wherein the synthesized NaInO2 has high purity, the material preparation process is simple, and a NaInO2+In(OH)3 composite material is obtained by simple mechanical mixing. In addition, the obtained composite material is applied as an electrolyte to a power generation unit of a SOFC for the first time, thereby obtaining a new electrolyte material with good low-temperature electrochemical properties.

[0024] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0027] Figure 1 XRD spectra of NaInO2 and NaInO2+20%In(OH)3 composite electrolytes of the present invention after high-temperature calcination under different atmospheres;

[0028] Figure 2 This is an impedance spectrum diagram of the SOFC battery disclosed in Example 1 of the present invention using NaInO2+10%In(OH)3 as the electrolyte when operating at 350-550°C.

[0029] Figure 3The IV curve and power density curve of the SOFC battery using NaInO2+10%In(OH)3 as the electrolyte when operating at 350-550°C;

[0030] Figure 4 This is the impedance spectrum of the SOFC battery using NaInO2+20%In(OH)3 as the electrolyte when operating at 350-550°C;

[0031] Figure 5 The IV curve and power density curve of the SOFC battery of the present invention using NaInO2+20%In(OH)3 as the electrolyte when working at 350-550°C. DETAILED DESCRIPTION

[0032] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements, unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all possible embodiments consistent with the present invention. Rather, they are merely examples of methods consistent with certain aspects of the present invention, as detailed in the appended claims.

[0033] First, the present invention proposes a method for preparing a NaInO2-based composite material. By adjusting the raw material ratio in the synthesis process, pure-phase NaInO2 is obtained, and it is compounded with In(OH)3 in different proportions to prepare a composite material. For the first time, the obtained composite material is applied as an electrolyte to the power generation unit of SOFC, which further reduces the operating temperature of SOFC and exhibits good battery power output performance.

[0034] Specifically, a method for preparing a NaInO2-based composite material comprises:

[0035] Step 1, weighing Na2CO3 and In2O3 with a molar ratio of 2:1 as raw materials for standby use;

[0036] Step 2: Dissolve the mixed raw materials in 95% alcohol solution and stir at a constant temperature of 60°C for 12 hours to form a uniform mixed solution;

[0037] In step 2, sufficient alcohol and sufficient stirring time are used to ensure that Na2CO3 and In2O3 are fully mixed, so that the excess Na2CO3 in step 1 is fully attached to the surface of In2O3, avoiding complex pretreatment and saving costs. At the same time, it ensures that the pure product NaInO2 can be prepared, avoiding the generation of impurities and waste of resources.

[0038] Step 3: Place the mixed solution in a drying oven and evaporate to dryness to obtain a precursor powder at a drying temperature of 120°C;

[0039] Step 4: calcining the evaporated precursor powder in a muffle furnace at 1000° C. for 5 hours;

[0040] Step 5: Cooling the calcined powder and grinding it into fine powder;

[0041] Step 6: The obtained powder sample was filtered and washed three times in a vacuum filter to wash away excess Na2CO3, with 300 mL of pure water used each time;

[0042] Step 7: evaporate the filtered sample to dryness, grind it, and finally obtain dry NaInO2 powder. Figure 1 It can be seen that the synthesized material is a NaInO2 layered oxide with good single-phase properties and a typical R3m (rhombohedral) structure. Its crystal structure is composed of NaO6 and InO6 octahedral layers arranged alternately along the c-axis, forming a stacked layer structure;

[0043] Step 8: Mix NaInO2 powder and In(OH)3 powder in a mass ratio of 1:x (x=0.1, 0.2).

[0044] Step 9: Grind the mixed powder in a mortar for 20 minutes to obtain the target product, NaInO2+In(OH)3 composite material.

[0045] Step 10: calcine the NaInO2+20%In(OH)3 composite electrolyte material powder obtained in step 8 at 450°C in an oxygen atmosphere for 5 hours. Figure 1 It can be seen that part of the indium hydroxide of the composite electrolyte material after calcination in an oxygen atmosphere recrystallizes to form a stable indium oxide (In2O3) phase due to the oxidation reaction.

[0046] Step 11: calcine the NaInO2+20%In(OH)3 composite electrolyte material powder obtained in step 8 at 450°C in a hydrogen atmosphere for 5 hours. Figure 1 It can be seen that after calcining in a hydrogen atmosphere, part of the indium hydroxide in the composite electrolyte material forms an indium oxide (In2O3) phase and elemental indium due to the reduction reaction.

[0047] The present invention constructs a heterojunction with NaInO2 by generating a second product by In(OH)3 working in different atmospheres, and increases the oxygen vacancy concentration of the NaInO2 matrix material by in-situ growth of the second product on the surface of NaInO2, promotes the conduction of oxygen ions and hydrogen protons, and prepares an aInO2+x%In(OH)3 composite electrolyte material with high ionic conductivity.

[0048] The present invention is further explained below with reference to specific embodiments, but is not intended to limit the scope of protection of the present invention.

[0049] Example 1

[0050] Step 1: Mix 2.1198g of Na2CO3 and 2.7764g of In2O3.

[0051] Step 2: Mix the mixed powder with 95% alcohol solution and place it in a constant temperature magnetic stirrer at 60°C for 12 hours to form a uniform mixed solution.

[0052] Step 3: Place the mixed solution in a drying oven and evaporate to dryness to obtain precursor powder at a drying temperature of 120°C.

[0053] Step 4: Place the evaporated precursor powder in a muffle furnace and calcine at 1000° C. for 5 hours.

[0054] Step 5: Grind the treated powder into fine powder after cooling, and filter it three times in a vacuum filter, using 300 mL of purified water each time.

[0055] Step 6: Evaporate the filtered sample to dryness and grind it to obtain a dry fine powder.

[0056] Step 7: Mix the powder with 0.48962 g of In(OH)3 powder.

[0057] Step 8: Mechanically mix the mixed powder in a mortar for 20 minutes to obtain the target product, NaInO2+10%In(OH)3 composite material.

[0058] The composite material is used as an electrolyte material in a power generation unit of a SOFC; specifically, the process includes the following steps:

[0059] Drop terpineol into Ni 0.8 Co 0.15 Al 0.05 LiO 2-δ (NCAL) powder, the preparation of the slurry needs to be based on the mass ratio of pineol and ethyl cellulose of 97:3. After weighing, mix, heat and stir evenly. Put the NCAL powder into a mortar, drop the slurry into the mixture and grind it into a uniform mixed material; use a 13mm puncher to knock to obtain a disc-shaped nickel foam, one side of the disc is horizontal and the other side is a convex surface. After placing the convex surface on top, use a brush to dip the mixed slurry and brush it evenly on the nickel foam. After drying, repeat the brushing 2-3 times until the gaps in the nickel foam are filled with NCAL material and the surface is uniform and flat; place the coated nickel foam disc in a blast drying oven set to 120℃ and bake for 20 minutes to finally obtain a dry NCAL electrode disc.

[0060] First, place the electrode sheet with the convex surface facing upwards at the bottom of a mold with a diameter of 13mm, weigh 0.32-0.34g of NaInO2+10%In(OH)3 composite electrolyte sample powder NaInO2+In(OH)3 composite material, pour the powder into the mold and spread it evenly, compact it slightly with the mold pressure rod, then place another electrode sheet with the convex surface facing downwards and press it tightly. Place the mold on the tablet press platform and hold it at a pressure of 10MPa for 80s to form a battery sheet; before testing a single battery, the battery sheet needs to be placed in the fixture and clamped, then fixed with screws. There may be short circuit leakage on the cylindrical side of the battery sheet, so it needs to be polished with sandpaper to ensure that the battery is normal. At this time, the effective area of ​​the battery participating in the electrochemical reaction is 0.64cm 2 ; After heating the muffle furnace to 550℃, place the fixture with the battery in it. Heat treatment is required for 30 minutes before testing. After the heat treatment, hydrogen and oxygen with a flow rate of 130mL / min and 35mL / min are respectively introduced into the inlet pipe of the fixture. During the cooling process, the impedance and battery performance of the full battery are tested at different temperatures, such as Figure 2 、 3 shown. Figure 2 The Nyquist impedance spectrum of a SOFC cell with NaInO2 + 10% In(OH)3 as the electrolyte, operating at 350-550°C, is shown. The figure shows that the impedance of the composite electrolyte decreases with increasing temperature, a characteristic of thermally activated ionic conduction and follows the Arrhenius conductivity behavior. The Nyquist plot displays a semicircle in the high-frequency region and a partial arc in the low-frequency region. The high-frequency response is typically related to the bulk resistance of the electrolyte material, while the low-frequency tail may be affected by electrode polarization or grain boundary resistance. Figure 3 NaInO2

[0061] The IV curve and power density curve of the SOFC cell with +10% In(OH)3 as electrolyte working at 350-550℃. As can be seen from the figure, due to the enhancement of ionic conductivity at higher temperatures, the maximum power density of the cell increases with the increase of operating temperature. The power density at 550℃ can reach 483mW / cm 2 , demonstrating excellent electrochemical performance. The cell voltage decreases with increasing current density, consistent with typical ohmic losses and polarization effects in SOFCs. The open-circuit voltage (OCV) is relatively stable over the test temperature range of 350-550°C, indicating that the electrolyte has good ionic conductivity and minimal electronic conductivity.

[0062] Example 2

[0063] Step 1: Mix 2.1198g of NaCO3 and 2.7764g of In2O3.

[0064] Step 2: Mix the mixed powder with 95% alcohol solution and place it in a constant temperature magnetic stirrer at 60°C for 12 hours to form a uniform mixed solution.

[0065] Step 3: Place the mixed solution in a drying oven and evaporate to dryness to obtain precursor powder at a drying temperature of 120°C.

[0066] Step 4: Place the evaporated precursor powder in a muffle furnace and calcine at 1000° C. for 5 hours.

[0067] Step 5: Grind the treated powder into fine powder after cooling, and filter it three times in a vacuum filter, using 300 mL of purified water each time.

[0068] Step 6: Evaporate the filtered sample to dryness and grind it to obtain a dry fine powder.

[0069] Step 7: Mix the powder with 0.97924 g of In(OH)3 powder.

[0070] Step 8: Mechanically mix the mixed powder in a mortar for 20 minutes to obtain the target product, NaInO2+20%In(OH)3 composite material.

[0071] The composite material is used as an electrolyte material in a power generation unit of a SOFC; specifically, the process includes the following steps:

[0072] Drop terpineol into Ni 0.8 Co 0.15 Al 0.05 LiO 2-δ (NCAL) powder, the preparation of the slurry requires weighing according to the mass ratio of pineol and ethyl cellulose of 97:3, then mixing, heating and stirring evenly, placing the NCAL powder in a mortar, dripping the slurry into the mixture and grinding into a uniform mixed material; using a 13mm puncher to knock to obtain a disc-shaped nickel foam, one side of the disc is horizontal and the other side is a convex surface, placing the convex surface on top and using a brush to dip the mixed slurry and evenly brush it on the nickel foam, drying and repeating the brushing 2-3 times until the gaps in the nickel foam are filled with NCAL material and the surface is uniform and flat; the coated nickel foam disc is placed in a blast drying oven set to 120℃ and baked for 20 minutes to finally obtain a dry NCAL electrode disc.

[0073] First, place the electrode sheet with the convex side facing upwards at the bottom of a mold with a diameter of 13mm. Weigh 0.32-0.34g of NaInO2+20%In(OH)3 composite electrolyte sample powder NaInO2+In(OH)3 composite material. Pour the powder into the mold and spread it evenly. Use the mold pressure rod to lightly compact it, then place another electrode sheet with the convex side facing downwards and press it tightly. Place the mold on the tablet press platform and hold it at a pressure of 10MPa for 80s to form a battery sheet. Before testing a single battery, place the battery sheet into the fixture, clamp it, and then secure it with screws. There may be short circuit leakage on the cylindrical side of the battery sheet, so it needs to be polished with sandpaper to ensure that the battery is normal. At this time, the effective area of ​​the battery participating in the electrochemical reaction is 0.64cm. 2 ; After heating the muffle furnace to 550℃, place the fixture with the battery in it. Heat treatment is required for 30 minutes before testing. After the heat treatment, hydrogen and oxygen with a flow rate of 130mL / min and 35mL / min are respectively introduced into the inlet pipe of the fixture. During the cooling process, the power density of the full battery is tested at different temperatures. Figure 4 This is the Nyquist impedance spectrum of a SOFC battery with NaInO2+20%In(OH)3 as electrolyte working at 350-550℃. Figure 4 The impedance of the composite electrolyte decreases with increasing temperature. This is a characteristic of thermally activated ionic conduction, which follows the Arrhenius conductivity principle. The Nyquist plot shows a semicircle in the high-frequency region and an irregular arc in the low-frequency region. The high-frequency response is generally related to the bulk resistance of the electrolyte material, while the low-frequency tail may be affected by electrode polarization effects or grain boundary resistance. Figure 5 The IV curve and power density curve of a SOFC cell with NaInO2 + 20% In(OH)3 as the electrolyte operating at 350-550°C. As can be seen from the figure, the maximum power density of the cell increases with increasing operating temperature due to the enhanced ionic conductivity at higher temperatures. The power density at 550°C can reach 512mW / cm 2 , demonstrating excellent electrochemical performance. The cell voltage decreases with increasing current density, consistent with typical ohmic losses and polarization effects in SOFCs. The open-circuit voltage (OCV) is relatively stable over the test temperature range of 350-550°C, indicating that the electrolyte material of this invention has good ionic conductivity and minimal electronic conductivity.

[0074] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.

[0075] It should be understood that the present invention is not limited to the above description and that various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for preparing a NaInO2-based composite material, characterized in that: include: Step 1: Mix Na2CO3 and In2O3 and dissolve them in 95% alcohol solution. Stir at a constant temperature to form a uniform mixed solution. Step 2: drying the mixed solution to obtain a precursor powder; Step 3: After calcining the precursor powder, cooling and grinding into fine powder; Step 4: Wash the finely crushed powder to remove excess Na2CO3; Step 5: The cleaned powder is evaporated and ground in sequence to obtain a dry fine powder; Step 6: Mix the dried fine powder with In(OH)3 powder and grind them thoroughly to obtain NaInO2 +In(OH)3 composite material; In step 1, the molar ratio of Na2CO3 and In2O3 is 2:1; In step 6, the mass ratio of the dried fine powder to the In(OH)3 powder is 1:x, where x=0.1, 0.

2.

2. The method for preparing a NaInO2-based composite material according to claim 1, characterized in that: The constant temperature stirring condition in step 1 is stirring at a constant temperature of 60° C. for 12 h.

3. The method for preparing a NaInO2-based composite material according to claim 1, characterized in that: The drying temperature in step 2 is 120°C.

4. The method for preparing a NaInO2-based composite material according to claim 1, characterized in that: The calcination parameters in step 3 are: calcination at 1000° C. for 5 hours.

5. The method for preparing a NaInO2-based composite material according to claim 1, characterized in that: The cleaning of the finely pulverized powder in step 4 includes three filtration cleanings in a vacuum filter, each time using 300 mL of pure water.

6. An electrolyte material, characterized in that The electrolyte material comprises a NaInO2-based composite material prepared by the preparation method according to any one of claims 1 to 5.

7. Use of the electrolyte material according to claim 6, characterized in that: Applied to the SOFC power generation unit.

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