An efficient ammonia fuel proton-conducting solid oxide fuel cell and its preparation method

Abstract

The present invention relates to the technical field of solid oxide fuel cells, and particularly relates to a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell and a preparation method thereof. The high-efficiency ammonia fuel proton-conducting solid oxide fuel cell comprises a cathode, an electrolyte and an anode. The cathode is PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ , the electrolyte is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3‑δ , the anode is NiO-BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3‑δ . The cathode and the anode are connected by a wire. By using a Ni / Al2O3 catalyst and optimizing the microstructure, the present invention significantly improves the cracking efficiency of ammonia and the electrochemical reaction rate, and improves the performance and durability of the battery components.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide fuel cells, and particularly relates to a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell and a preparation method thereof. Background Art

[0002] A solid oxide fuel cell (SOFC) is a high-efficiency energy conversion device that directly converts the chemical energy of fuel into electrical energy through an electrochemical reaction. Traditional thermal power generation usually relies on burning fossil fuels, which is not only inefficient (generally only 30%-40%), but also produces a large amount of greenhouse gases and other pollutants. In contrast, SOFC has a higher energy conversion efficiency, which can reach 50%-60% or even higher, and the emissions are cleaner, so the environmental pollution is lower.

[0003] In the SOFC technology, proton-conducting SOFCs (PC-SOFCs) have significant advantages compared with traditional oxygen-ion-conducting SOFCs. PC-SOFCs can operate efficiently at about 700 °C, reducing the material challenges and costs brought by high temperatures. In addition, due to the proton conduction mechanism, PC-SOFCs have a higher conversion efficiency for hydrogen or other renewable fuels, which helps to improve the overall battery performance.

[0004] In terms of fuel selection, ammonia, as a potential fuel source, has significant advantages compared with hydrogen fuel and other traditional fuels. The storage and transportation of ammonia are safer and more economical than hydrogen, because hydrogen needs to be stored at extremely low temperatures or high pressures, which places higher requirements on equipment. Ammonia is also a carbon-neutral fuel, containing no carbon and producing no carbon dioxide when burned, so it is environmentally friendly. In addition, the global production and supply chain of ammonia are already very mature, making it an ideal choice for realizing large-scale renewable energy applications. However, traditional fuel cells prepared using ammonia as fuel also face the problems of low ammonia cracking efficiency and low electrochemical reaction rate, so the effective utilization of ammonia cannot be achieved. Summary of the Invention

[0005] Aiming at the technical problems of low ammonia cracking efficiency and low electrochemical reaction rate existing in the ammonia fuel proton-conducting solid oxide fuel cell, the present invention provides a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell and a preparation method thereof. By using a Ni / Al2O3 catalyst and optimizing the anode microstructure, the ammonia cracking efficiency and the electrochemical reaction rate are significantly improved; at the same time, the present invention combines advanced material synthesis technology and a relatively cost-effective process flow, simplifies the preparation process, and improves the performance and durability of the battery components.

[0006] In the first aspect, the present invention provides a preparation method of a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell, including the following steps:

[0007] (1) Preparation of battery cathode: Dissolve metal salts in deionized water according to the stoichiometric ratio of PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ . Add citric acid and ethylenediaminetetraacetic acid as chelating agents to the metal salt solution, adjust the pH, and then heat the solution until a gel is formed. Keep it at 400 °C for 6 h and then calcine it at 1050 °C for 10 h to obtain the cathode.

[0008] (2) Preparation of electrolyte by solid-phase reaction: Disperse metal salts and metal oxides in ethanol medium according to the stoichiometric ratio of BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ . Ball-mill them, dry the obtained precursor powder, and press it into a mold. Calcinate the formed green body at 1150 °C for 10 h. Grind the calcined electrolyte green body and mix it with a solution of polyvinylpyrrolidone and polyethersulfone in N-methylpyrrolidone to obtain an electrolyte slurry. After calcining at 1380 °C for 5 h and then grinding, obtain BZCYYb electrolyte powder.

[0009] (3) In-situ phase formation to prepare an anode with dendritic pore structure: Disperse metal salts and metal oxides in ethanol medium according to the stoichiometric ratio of NiO-BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ . At the same time, add a solution of polyethersulfone in N-methylpyrrolidone and Ni / Al2O3 catalyst. The addition amount of Ni / Al2O3 catalyst is 10% of the total mass of metal salts and metal oxides. Ball-mill to obtain an anode slurry. Prepare the anode green body by grid-assisted phase inversion method, and then calcine it at 950 °C for 2 h to obtain an anode substrate with a unique dendritic structure and certain strength.

[0010] (4) Preparation of half-cell: Mix the electrolyte with polyvinylpyrrolidone, add ethanol, and roll-mill to obtain an electrolyte slurry. Dip-coat the electrolyte slurry on the anode substrate obtained in step (3) and calcine it at 1480 °C for 5 h to obtain a half-cell with a dense electrolyte.

[0011] (5) Preparation of high-efficiency ammonia fuel proton-conducting solid oxide fuel cell: Mix the cathode material with polyvinylpyrrolidone, add ethanol, and roll-mill to obtain a battery cathode slurry. Spray the battery cathode slurry on the surface of the half-cell with a dense electrolyte to deposit a cathode layer, and co-fire it at 1050 °C for 2 h to obtain a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell.

[0012] (6) Preparation of wire: Apply silver paste to both ends of the cathode and anode of the high-efficiency ammonia fuel proton-conducting solid oxide fuel cell and connect them to silver wires. Co-fire them in a muffle furnace at 400 °C to obtain a fuel cell with silver wires serving as wires for the anode and cathode.

[0013] Further, in step (1), the metal salts are praseodymium nitrate, barium nitrate, strontium nitrate, cobalt nitrate, and iron nitrate.

[0014] Further, in step (1), the weight ratio of citric acid, ethylenediaminetetraacetic acid to the metal salts is 1:2:1.

[0015] Further, in step (1), use ammonia water to adjust the pH value of the solution to 7.0 - 8.0.

[0016] Further, in step (2), the metal salt is barium carbonate, and the metal oxides are cerium oxide, zirconium oxide, yttrium oxide, and ytterbium oxide.

[0017] Further, in step (3), the metal salt is barium carbonate, and the metal oxides are cerium oxide, zirconium oxide, yttrium oxide, ytterbium oxide, and nickel oxide, where nickel oxide is used as a sintering aid.

[0018] In a second aspect, the present invention also provides a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell prepared by the above preparation method, including a cathode, an electrolyte, and an anode. The cathode is PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ , the electrolyte is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ , the anode is NiO - BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ , and the cathode and the anode are connected by a wire.

[0019] Further, the wire is a silver wire.

[0020] The beneficial effects of the present invention are as follows:

[0021] 1. Storage, transportation, and usage advantages of ammonia fuel: Compared with hydrogen fuel, ammonia is easier to store and transport. It can be stored in liquid form under normal pressure, reducing the cost and technical difficulty of storage and transportation. In addition, the energy density of ammonia is higher than that of hydrogen, providing a more efficient solution for energy storage.

[0022] 2. Improved ammonia cracking efficiency: By adopting innovative anode materials and structural designs, the dendritic porous anode of the present invention can load the catalyst into the interior of the anode, which decomposes the fuel in cooperation with the anode material, significantly improving the cracking efficiency of ammonia and the rate of electrochemical reactions in the fuel cell. This efficiency improvement means that the battery can utilize ammonia more effectively, increasing power output and overall battery performance. The present invention is formed by one-step sintering after preparing the film with raw material ratios, with extremely low raw material costs, greatly reducing energy consumption and saving the production cycle.

[0023] 3. Reduced operating costs and complexity: A new method for preparing proton batteries is adopted, simplifying the preparation process, while improving the performance and durability of battery components, and further reducing the overall cost of the system.

[0024] 4. Environmentally friendly and sustainable: Since ammonia is a fuel without carbon emissions, the PC-SOFCs system of the present invention has significant advantages in reducing environmental pollution, contributing to the development and application of clean energy technologies.

[0025] 5. Enhanced market competitiveness: Combining the multiple advantages of ammonia as a fuel, the PC-SOFCs system of the present invention can become a competitive energy solution in commercial and industrial applications. Description of the Drawings

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 It is the cross-sectional electron micrograph of the battery anode prepared in Example 1 of the present invention.

[0028] Figure 2 It is the I-V-P curve of the single cell prepared in Example 1 of the present invention under different concentrations of ammonia gas atmospheres.

[0029] Figure 3 It is the I-V-P curve of the single cell of the non-porous battery anode prepared by the traditional tabletting method under different concentrations of ammonia gas atmospheres. Detailed Embodiments

[0030] To enable those skilled in the art to better understand the technical solutions in the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0031] Embodiment 1

[0032] An efficient ammonia fuel proton-conducting solid oxide fuel cell includes a cathode, an electrolyte, and an anode. The cathode is PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ , the electrolyte is BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ , the anode is NiO-BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ , and the cathode and the anode are connected by a silver wire. The preparation method of the fuel cell is specifically as follows:

[0033] (1) Prepare a perovskite cathode material PBSCF with the ability to conduct three types (O 2- , H + , e - )

[0034] (11) Dissolve 4.3501 g of Pr(NO3)3, 1.3067 g of Ba(NO3)2, 1.0582 g of Sr(NO3)2, 2.7441 g of Co(NO3)2, and 1.2393 g of Fe(NO3)3 in 20 g of deionized water, and stir in an 80°C oil bath until completely dissolved;

[0035] (12) Add citric acid and ethylenediaminetetraacetic acid as chelating agents to the metal salt solution obtained in step (11), and the weight ratio of citric acid, ethylenediaminetetraacetic acid to the metal salt is 1:2:1;

[0036] (13) Use ammonia water to adjust the pH value to 7.0 - 8.0 to make the solution in an alkaline atmosphere;

[0037] (14) Then heat the solution in an oil bath to 80°C to form a gel;

[0038] (15) Keep at 400 °C for 6 h to remove organic residues;

[0039] (16) Calcination at 1050 °C for 10 h gave PBSCF powder.

[0040] (2) Preparation of proton-conducting perovskite electrolyte material BZCYYb by solid-phase reaction

[0041] (21) 16.6 g of BaCO3, 16.6 g of ZrO2, 16.6 g of Yb2O3, 16.6 g of Y2O3, and 16.6 g of CeO2 were dispersed in an ethanol medium, with the amount of ethanol being enough to cover the metal salts and metal oxide powders, and then milled in a planetary ball mill for 48 h;

[0042] (22) drying the precursor powder in an oven at 80 °C, pressing the precursor powder into a tablet with a diameter of about 15 mm at a pressure of 12 MPa using a tablet press to obtain an electrolyte green body, and calcining the electrolyte green body at 1150 °C for 10 h;

[0043] (23) The calcined electrolyte green body was ground, the obtained powder was mixed with 0.72 g of polyvinyl pyrrolidone, 20 g of 22.4 wt% polyethersulfone N-methylpyrrolidone solution was added, and the mixture was ball milled in a planetary ball mill for 24 h to obtain an electrolyte slurry;

[0044] (24) The electrolyte slurry was heated to 1380 °C in a muffle furnace at a rate of 5 °C / min and kept at this temperature for 300 min. After natural cooling, it was ground again and passed through a 300-mesh sieve to obtain BZCYYb electrolyte powder.

[0045] (3) In-situ preparation of proton-conducting perovskite anode substrate NiO-BZCYYb

[0046] (31) 3.0 g NiO, 16.6 g BaCO3, 16.6 g ZrO2, 16.6 g Yb2O3, 16.6 g Y2O3, 16.6 g CeO2, and 0.72 g PVP were dispersed in an ethanol medium in an amount sufficient to cover the powders. 20 g 17.6 wt% polyethersulfone solution in N-methylpyrrolidone and Ni / Al2O3 catalyst were added at the same time. The amount of Ni / Al2O3 catalyst added was 10% of the total mass of the metal salt and the metal oxide. The mixture was milled in a planetary ball mill for 48 h to obtain the anode slurry NiO-BZCYYb.

[0047] The Ni / Al2O3 catalyst can be prepared by coprecipitation, deposition precipitation, or melt infiltration, or purchased from the market. The Ni / Al2O3 catalyst used in this embodiment is obtained by the following method:

[0048] Mix 0.5 M nickel nitrate solution and 0.5 M aluminum nitrate solution in a volume ratio of 1:1. Then add an equal volume of 1 M sodium carbonate solution to the mixed solution, stir at 60 °C for 1 h, filter, wash with water, dry the filter cake, grind and sieve it. Load the sieved powder into a tubular furnace, introduce nitrogen and hydrogen, calcine at 550 °C for 5 h, and pass nitrogen for passivation after cooling with the furnace to obtain the product;

[0049] (32)Adopt the grid-assisted phase inversion method. Use a 5 mL syringe to add the anode slurry into the mold, cover it with a wire mesh with a pore size of 150 μm, inject deionized water, dry it after phase conversion for 2 h to obtain the green anode;

[0050] (34)Subsequently, put the green anode into a muffle furnace and heat it to 950 °C at a rate of 5 °C / min, hold for 2 h, and wait for the tubular furnace to cool naturally to obtain an anode substrate with a unique dendritic pore structure (as shown in Figure 1 shown) and a certain strength.

[0051] (4)Prepare the half-cell

[0052] (41)Mix 3 g of the BZCYYb electrolyte powder prepared in step (2) with 0.1 g of PVP, then add 30 mL of ethanol, and roll mill on a roll mill for 24 h to obtain the electrolyte slurry;

[0053] (42)Dip and coat the electrolyte slurry on the anode substrate in step (3);

[0054] (43)After drying the anode substrate impregnated with the electrolyte solution in an oven at 60 °C, put it into a muffle furnace and heat it to 1480 °C at a rate of 5 °C / min for co-firing, and then hold for 300 min to prepare a half-cell with a dense electrolyte.

[0055] (5)Prepare a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell

[0056] (51)Mix 3 g of the cathode material PBSCF prepared in step (1) with 0.1 g of PVP, then add 30 mL of ethanol, and roll mill on a roll mill for 24 h to obtain the battery cathode slurry;

[0057] (52)Spray the battery cathode slurry onto the surface of the half-cell with a dense electrolyte through a fine spray gun to deposit a cathode layer;

[0058] (53)Put it into a muffle furnace and heat it to 1050 °C at a rate of 5 °C / min for co-firing for 2 h to obtain a high-efficiency ammonia fuel proton-conducting solid oxide fuel cell (PBSCF|BZCYYb|NiO-BZCYYb).

[0059] (6) Preparation of the wire: Apply silver paste to both ends of the cathode and anode of the high-efficiency ammonia fuel proton-conducting solid oxide fuel cell and connect them to silver wires. Co-fire them in a muffle furnace at 400 °C to obtain a single cell with silver wires serving as wires for the anode and cathode.

[0060] Seal the prepared single cell on a quartz tube with silver glue and then place it in an experimental furnace. The cathode of the cell is exposed to the air atmosphere, and pure H2 is introduced as fuel into the anode side of the cell to reduce NiO. Then, control the flow rates of the ammonia fuel gas and the argon gas. Compare the performance of the single cells under different ammonia concentrations (40% NH3, 66.7% NH3, 80% NH3, 100% NH3) respectively, and compare with the single cell of the porous-free cell anode prepared by the traditional tabletting method. The results are as Figure 2 、 3 shown. It can be seen that the single cell prepared by the present invention can effectively utilize more reactants to generate current, output more energy, and has a higher ammonia cracking efficiency; and compared with the traditional tabletting method, the grid-assisted phase inversion method used in the present invention can improve the anode morphology structure and optimize the key parameters such as the porosity, pore size distribution, and specific surface area of the anode sheet, which is beneficial to improving the electrochemical performance of the cell.

[0061] Although the present invention has been described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, those of ordinary skill in the art can make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions should all be within the scope of the present invention. / Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention.

Claims

1. A method for preparing a high-efficiency ammonia fuel proton conductor solid oxide fuel cell, characterized in that: The steps include: (1) Preparation of battery cathode: metal salt is pressed into PrBa 0.5 Sr 0.5 Co 1.5 Fe 0.5 O 5+δ The stoichiometric ratio is dissolved in deionized water, citric acid and ethylenediaminetetraacetic acid are used as chelating agents and added to the metal salt solution, the pH is adjusted and the solution is heated until a gel is formed, and then the solution is kept at 400°C for 6 hours and then calcined at 1050°C for 10 hours to obtain; (2) Preparation of electrolyte by solid phase reaction: metal salt and metal oxide are reacted according to BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ The precursor powder obtained by ball milling in an ethanol medium in a stoichiometric ratio is dried and pressed into a mold, and the molded body is calcined at 1150°C for 10 hours. The calcined electrolyte green body is ground and mixed with a polyvinyl pyrrolidone and polyether sulfone N-methyl pyrrolidone solution to obtain an electrolyte slurry, which is calcined at 1380°C for 5 hours and then ground to obtain a BZCYYb electrolyte powder; (3) In-situ preparation of anodes with dendritic pore structures: metal salts and metal oxides are mixed in a NiO-BaZr 0.1 Ce 0.7 Y 0.1 Yb 0.1 O 3-δ The anode slurry was obtained by ball milling. The anode green body was prepared by grid-assisted phase inversion method, and then calcined at 950°C for 2h to obtain the anode substrate. The Ni / Al2O3 catalyst was obtained by the following method: 0.5M nickel nitrate solution and 0.5M aluminum nitrate solution are mixed in a volume ratio of 1:1, and then an equal volume of 1M sodium carbonate solution is added to the mixed solution, stirred at 60°C for 1 hour, filtered and washed with water, the filter cake is dried, ground and sieved, and the sieved powder is loaded into a tubular furnace, nitrogen and hydrogen are introduced, and calcined at 550°C for 5 hours, and nitrogen is introduced for passivation as the furnace is cooled to obtain; (4) preparing a half-cell: mixing the electrolyte powder prepared in step (2) with polyvinyl pyrrolidone, adding ethanol, and roller milling to obtain an electrolyte slurry, and applying the electrolyte slurry to the anode substrate of step (3) by dip-coating, and calcining at 1480° C. for 5 h to obtain a half-cell having a dense electrolyte; (5) Preparation of high-efficiency ammonia fuel proton conductor solid oxide fuel cell: cathode material and polyvinyl pyrrolidone are mixed, ethanol is added, and the battery cathode slurry is obtained by roller grinding. The battery cathode slurry is sprayed onto the surface of the half-cell with dense electrolyte to deposit a cathode layer, and the mixture is co-fired at 1050°C for 2h to obtain a high-efficiency ammonia fuel proton conductor solid oxide fuel cell; (6) Preparation of wires: Silver paste is applied to both ends of the cathode and anode of a high-efficiency ammonia fuel proton conductor solid oxide fuel cell and connected with silver wires. The two are co-fired in a muffle furnace at 400°C to obtain a battery with silver wires acting as wires at the anode and cathode.

2. The preparation method according to claim 1, characterized in that In step (1), the metal salt is praseodymium nitrate, barium nitrate, strontium nitrate, cobalt nitrate and iron nitrate.

3. The preparation method according to claim 1, characterized in that: In step (1), the weight ratio of citric acid, ethylenediaminetetraacetic acid and metal salt is 1:2:

1.

4. The preparation method according to claim 1, characterized in that: In step (1), the pH value of the solution is adjusted to 7.0-8.0 using aqueous ammonia.

5. The preparation method according to claim 1, characterized in that: In step (2), the metal salt is barium carbonate, and the metal oxides are cerium oxide, zirconium oxide, yttrium oxide and ytterbium oxide.

6. The preparation method according to claim 1, characterized in that: In step (3), the metal salt is barium carbonate, and the metal oxide is cerium oxide, zirconium oxide, yttrium oxide, ytterbium oxide and nickel oxide.

7. A high-efficiency ammonia fuel proton conductor solid oxide fuel cell prepared by the preparation method as described in any one of claims 1 to 6.

Images