Preparation method and application of air electrode material of perovskite type proton ceramic battery

Abstract

The invention relates to the technical field of reversible proton ceramic electrochemical cells (R-PCECs), and aims to solve the technical problem that the expandability of the existing R-PCECs is limited due to insufficient activity of an oxygen electrode. Therefore, the invention provides a novel oxygen electrode material and a preparation method thereof, and the novel oxygen electrode material is developed by doping potassium (K) at the A site of Ba (Co < 0.7 > Fe < 0.3 >) < 0.85 > Ta0. 15O < 3-delta > (BCFT). Experimental verification shows that by introducing the K element into BCFT, oxygen vacancy formation and proton absorption can be effectively promoted, the oxygen exchange capacity of the material is enhanced, and then the catalytic activity of an oxygen electrode is improved. When the K-doped BKCFT10 is used as the oxygen electrode to be applied to R-PCECs, the performance of the cell in a fuel cell mode (at 650 DEG C and 1206 mW cm <-2 >) is obviously superior to that of a cell adopting an undoped BCFT oxygen electrode; meanwhile, the R-PCECs also have excellent operation stability in a fuel cell mode. The performance of the oxygen electrode material is optimized through element doping, and a key technical support is provided for promoting large-scale application of R-PCECs.

Description

Technical Field

[0001] This invention belongs to the field of solid oxide fuel cell technology, and relates to a method for preparing and applying an air electrode material for a perovskite proton ceramic battery. Background Technology

[0002] Energy is the foundation and driving force of human civilization, crucial for human survival and development, and vital for promoting economic and social development and improving people's well-being. With societal development, human demand for energy, especially electricity, is becoming increasingly strong. In recent years, my country's power generation has continued to grow, with thermal power accounting for over 70%. However, the efficiency of thermal power generation is only about 35%, and the exhaust gases produced during the power generation process cause serious environmental pollution. Excessive combustion of fossil fuels leads to an increase in the proportion of carbon dioxide in the atmosphere, contributing to the greenhouse effect and causing a continuous rise in global temperatures, seriously threatening the human living environment. Furthermore, fossil fuels are non-renewable resources; therefore, humanity needs to develop clean, renewable, and efficient energy conversion methods to meet rapidly growing energy demands.

[0003] Among numerous novel energy conversion methods, reversible solid oxide batteries (SOCs) are electrochemical devices that can convert the chemical energy of fuel into electrical energy. Due to their high conversion efficiency and environmental friendliness, they have received widespread attention and rapid development in recent years. SOCs can be divided into two modes: solid oxide fuel cell (SOFC) and solid oxide electrolyzer (SOEC). In the fuel cell mode, electricity is generated through an electrochemical reaction, unrestricted by the Carnot cycle, thus significantly improving energy conversion efficiency. SOFCs in combined heat and power systems achieve energy conversion efficiencies exceeding 80%. Furthermore, SOFCs greatly reduce emissions of harmful gases such as CO, NO, and SO₂ during power generation. In addition, SOFCs offer advantages such as wide fuel adaptability, all-solid-state operation, and modular assembly, and are widely considered a type of fuel cell with the potential for widespread application in the future. Solid oxide electrolyzers represent the reverse reaction of solid oxide fuel cells. In electrolysis mode, applying voltage converts electrical energy into chemical energy. This can be coupled with renewable energy sources such as solar, wind, and tidal power to store excess electrical energy as chemical energy, alleviating the increasingly severe energy crisis. Due to its high performance and conversion efficiency in both fuel cell and electrolytic cell modes, as well as its reversible operation flexibility, it has a very broad application prospect. Summary of the Invention

[0004] One objective of this invention is to provide a method for preparing and applying the aforementioned perovskite-type proton ceramic battery air electrode material. To achieve this objective, the technical solution adopted by this invention is as follows: A perovskite-type proton ceramic battery air electrode material, characterized in that the molecular formula of the perovskite-type proton ceramic battery air electrode material is Ba. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ , where x=0,0.05,0.10,0.15,0≤δ≤1,δ is the oxygen vacancy content.

[0005] This invention also provides a method for preparing the above-mentioned perovskite-type proton ceramic battery air electrode material, specifically including the following steps:

[0006] (1) According to the chemical formula Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ The stoichiometric ratio of the metal elements in the sample is determined by weighing samples containing Ba. 2+ carbonates containing K + carbonates containing Co 3+ oxides containing Fe 3+ oxides containing Ta 5+ Oxides;

[0007] (2) Place the powder weighed in step (1) into a ball mill jar, add an appropriate amount of ball milling beads and anhydrous ethanol, and ball mill;

[0008] (3) Take the slurry from step (2) out of the ball mill jar, dry it, and collect the powder;

[0009] (4) Place the powder from step (3) into a mold and press it into a round disc;

[0010] (5) The powder from step (4) is placed in a muffle furnace for pre-calcination;

[0011] (6) Place the powder that was pre-burned in step (5) into a mortar and grind it. After grinding it thoroughly, weigh an appropriate amount of powder and put it into a ball mill jar. Add an appropriate amount of ball milling beads and anhydrous ethanol, and then grind it again.

[0012] (7) Place the powder from step (6) into a mold and press it into a round disc;

[0013] (8) Place the pressed sheet from step (7) into a high-temperature furnace for calcination;

[0014] (9) Place the calcined sample piece from step (8) into a mortar, add an appropriate amount of anhydrous ethanol for grinding, and dry the sample after thorough grinding to obtain perovskite-type proton ceramic battery air electrode material powder.

[0015] Preferably, step (1) contains Ba 2+ The carbonate is BaCO3, containing K + The carbonate is K2CO3, containing Co. 3+ The oxide is Co3O4, containing Fe 3+ The oxide is Fe2O3, containing Ta 5+ The oxide is Ta2O5.

[0016] Preferably, in steps (2) and (6), the ratio of grinding balls added to the grinding jar to the sample is (9-11):1, and the grinding time is 24 hours.

[0017] Preferably, in steps (4) and (7), the diameter of the tableting mold is 16mm and the pressure of the tableting machine oil gauge is 2-5Mpa.

[0018] Preferably, the pre-firing temperature in step (5) is 1000℃ and the pre-firing time is 10h.

[0019] Preferably, the calcination temperature in step (8) is 1100℃ and the calcination time is 10h.

[0020] Preferably, the molecular formula of the perovskite-type proton ceramic battery air electrode material obtained by the above preparation method is Ba. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Where x = 0, 0.05, 0.10, 0.15, 0 ≤ δ ≤ 1, and δ is the oxygen vacancy content. This invention also provides an application of a perovskite-type proton ceramic battery air electrode material, characterized by the following steps:

[0021] (1) Weigh an appropriate amount of the perovskite-type proton ceramic battery air electrode material Ba obtained above. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ NiO and polyvinyl butyral were calcined at 1000℃ and then mixed with graphite in an appropriate ratio. The mixture was then placed in a ball mill jar with an appropriate amount of alcohol and ball milled for 24 hours. The ball-milled powder was then taken out, dried, and ground to obtain anode support powder.

[0022] (2) An electrolyte film is prepared by double-powder dry pressing. An appropriate amount of the anode support powder obtained in step (1) is weighed and pressed into a sheet. Ba is placed on the pressed anode support. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ After the powder is formed, it is spread and compacted. The support is then placed in a muffle furnace for calcination, and the calcined support is polished to 300 μm for later use.

[0023] (3) After coating the oxygen electrode slurry onto the surface of the anode support obtained in step (2) above, put it into a tin furnace to dry, and then put the dried battery into a muffle furnace for calcination.

[0024] (4) Coat the surface of the battery obtained in step (3) with silver paste, attach silver wires to both sides of the battery, and then bake it in a tin furnace until dry. Finally, seal the battery with ceramic glue onto a ceramic tube and let it dry to obtain Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Solid oxide fuel cells using oxygen electrode materials.

[0025] Preferably, the calcination temperature in step (2) is 1450℃ and the calcination time is 5h.

[0026] Preferably, the calcination temperature in step (3) is 1000℃ and the calcination time is 2h.

[0027] This invention provides a perovskite-type proton ceramic battery air electrode material, its preparation method, and its application. Chemically, the oxygen electrode material has the chemical formula Ba. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ It exhibits a single perovskite structure. XRD characterization showed that the product synthesized in air had no impurity peaks and exhibited a stable cubic phase structure. Solid oxide fuel cells prepared using the perovskite-type proton ceramic battery air electrode material provided by this invention showed excellent electrochemical performance and stability under H2 atmosphere. Attached Figure Description

[0028] Figure 1 Ba, a high-entropy perovskite synthesized in air 1-x K x (Co0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ XRD pattern.

[0029] Figure 2 To use the material Ba of the present invention 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ The power density of a full cell made with oxygen electrode material in fuel cell mode.

[0030] Figure 3 For the purpose of this invention, Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Long-term stability of full cells fabricated using oxygen electrode materials under H2 atmosphere Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation steps, but the present invention is not limited to the following examples. The present invention provides a method for preparing a perovskite-type proton ceramic battery air electrode material, specifically including the following steps:

[0032] (1) According to the chemical formula Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ The stoichiometric ratio of the metal elements in the sample is determined by weighing samples containing Ba. 2+ The carbonate is BaCO3, containing K + The carbonate is K2CO3, containing Co. 3+ The oxide is Co3O4, containing Fe 3+ The oxide is Fe2O3, containing Ta 5+ The oxide is Ta2O5;

[0033] (2) Place the powder weighed in step (1) into a ball mill jar, add an appropriate amount of ball milling beads and anhydrous ethanol, and ball mill for 24 hours.

[0034] (3) Take the slurry from step (2) out of the ball mill jar, dry it, and collect the powder;

[0035] (4) Place the powder from step (3) into a mold with a diameter of 16 mm and press it into a disc under a pressure of 4 MPa;

[0036] (5) The powder from step (4) is placed in a muffle furnace for pre-calcination and then calcined at 1000°C for 10 hours in an air atmosphere.

[0037] (6) Place the powder that was pre-burned in step (5) into a mortar and grind it. After grinding it thoroughly, weigh an appropriate amount of powder and put it into a ball mill jar. Add an appropriate amount of ball milling beads and anhydrous ethanol, and then grind it again.

[0038] (7) Place the powder from step (6) into a mold with a diameter of 16 mm and press it into a disc under a pressure of 4 MPa;

[0039] (8) Place the pressed sheet from step (7) into a high-temperature furnace and calcine it at 1100°C for 10 hours in an air atmosphere;

[0040] (9) Place the calcined sample piece from step (8) into a mortar, add an appropriate amount of anhydrous ethanol for grinding, and dry the sample after thorough grinding to obtain perovskite-type proton ceramic battery air electrode material powder.

[0041] This invention provides an application of a perovskite-type proton ceramic battery air electrode material, characterized by the following steps:

[0042] (1) Weigh an appropriate amount of the perovskite-type proton ceramic battery air electrode material Ba obtained above. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ NiQ and polyvinyl butyral were calcined at 1000℃ and then mixed with graphite in an appropriate ratio. The mixture was then placed in a ball mill jar with an appropriate amount of alcohol and ball milled for 24 hours. The ball-milled powder was then taken out, dried, and ground to obtain anode support powder.

[0043] (2) An electrolyte film is prepared by double-powder dry pressing. An appropriate amount of the anode support powder obtained in step (1) is weighed and pressed into a sheet. Ba is placed on the pressed anode support. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ After the powder is formed, it is spread and compacted. The support is placed in a muffle furnace and calcined at 1450℃ for 5 hours. The calcined support is then polished to 300µm for later use.

[0044] (3) After coating the oxygen electrode slurry onto the surface of the anode support obtained in step (2) above, put it into a tin furnace to dry it. Then, put the dried battery into a muffle furnace and calcine it at 1000°C for 2 hours.

[0045] (4) Coat the surface of the battery obtained in step (3) with silver paste, attach silver wires to both sides of the battery, and then bake it in a tin furnace until dry. Finally, seal the battery with ceramic glue onto a ceramic tube and let it dry to obtain Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Solid oxide fuel cells using oxygen electrode materials.

[0046] (5) The cathode of the single cell obtained in step (4) is placed facing outwards and fixed in a muffle furnace. The cathode and anode of the single cell are connected to an electrochemical workstation via silver wires. Fuel gas (H2 and NH3) is introduced into the anode of the solid oxide fuel cell through a ceramic tube, while the cathode of the solid oxide fuel cell is placed in the ambient air atmosphere. Direct current is generated and output to the outside through the loss of electrons at the cathode and the gain of electrons at the anode at high temperature, thereby realizing the conversion of chemical energy into electrical energy.

[0047] The Ba prepared according to this invention was analyzed by X-ray diffraction. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Phase analysis of the oxygen electrode material powder, such as... Figure 1 This indicates that the material of the present invention has a simple structure and no obvious impurity peaks during the synthesis process.

[0048] For the material Ba of the present invention 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Electrochemical performance tests were conducted on a solid oxide fuel cell fabricated using oxygen electrode material. The power density test results of the cell under H2 are as follows: Figure 2 As shown, R-PCECs using the BKCFT10 oxygen electrode in fuel cell mode (1206 mW cm⁻¹ at 650 °C) -2 The performance of R-PCECs is significantly better than that of undoped BCFT. Furthermore, R-PCECs exhibit excellent stability in fuel cell mode.

[0049] The above description is only a preferred experimental example of the present invention. All equivalent changes and modifications made within the scope of the claims of the present invention shall be covered by the present invention.

Claims

1. A method for preparing an air electrode material for a perovskite-type proton ceramic battery, characterized in that, Its chemical formula is Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Where x = 0, 0.05, 0.10, 0.15, 0 ≤ δ ≤ 1, and δ is the oxygen vacancy content; the preparation method adopts the following steps: (1) According to the chemical formula Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ The stoichiometric ratio of the metal elements in the sample is determined by weighing samples containing Ba. 2+ carbonates containing K + carbonates containing Co 3+ oxides containing Fe 3+ oxides containing Ta 5+ Oxides; (2) Place the powder weighed in step (1) into a ball mill jar, add an appropriate amount of ball milling beads and anhydrous ethanol, and ball mill; (3) Take the slurry from step (2) out of the ball mill jar, dry it, and collect the powder; (4) Place the powder from step (3) into a mold and press it into a round disc; (5) The powder from step (4) is placed in a muffle furnace for pre-calcination; (6) Place the powder that was pre-burned in step (5) into a mortar and grind it. After grinding it thoroughly, weigh an appropriate amount of powder and put it into a ball mill jar. Add an appropriate amount of ball milling beads and anhydrous ethanol, and then grind it again. (7) Place the powder from step (6) into a mold and press it into a round disc; (8) Place the pressed sheet from step (7) into a high-temperature furnace for calcination; (9) Place the calcined sample piece from step (8) into a mortar, add an appropriate amount of anhydrous ethanol for grinding, and dry the sample after thorough grinding to obtain perovskite-type proton ceramic battery air electrode material powder.

2. The preparation method according to claim 1, characterized in that, Step (1) contains Ba 2+ The carbonate is BaCO3, containing K + The carbonate is K2CO3, containing Co. 3+ The oxide is Co3O4, containing Fe 3+ The oxide is Fe2O3, containing Ta 5+ The oxide is Ta2O5 as the raw material.

3. The preparation method according to claim 1, characterized in that, In steps (2) and (6), the ratio of grinding balls to sample balls added to the grinding jar is (9-11):1, and the grinding time is 24 hours.

4. The preparation method according to claim 1, characterized in that, In steps (4) and (7), the diameter of the tablet press mold is 16mm, and the pressure of the tablet press oil gauge is 2-5Mpa.

5. The preparation method according to claim 1, characterized in that, In step (5), the pre-firing temperature is 1000℃ and the pre-firing time is 10h.

6. The preparation method according to claim 1, characterized in that, In step (8), the calcination temperature is 1100℃ and the calcination time is 10h.

7. The application of the perovskite-type proton ceramic battery air electrode material prepared according to the method described in claims 1-6, characterized in that, The perovskite-type proton ceramic battery air electrode material is used to prepare the oxygen electrode in a solid oxide fuel cell.

8. The application according to claim 7, characterized in that, Solid oxide fuel cell is prepared using the following steps: (1) Weigh an appropriate amount of the perovskite-type proton ceramic battery air electrode material Ba obtained above. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ NiQ and polyvinyl butyral were calcined at 1000℃ and then mixed with graphite in an appropriate ratio. The mixture was then placed in a ball mill jar with an appropriate amount of alcohol and ball milled for 24 hours. The ball-milled powder was then taken out, dried, and ground to obtain anode support powder. (2) An electrolyte film is prepared by double-powder dry pressing. An appropriate amount of the anode support powder obtained in step (1) is weighed and pressed into a sheet. Ba is placed on the pressed anode support. 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ After the powder is formed, it is spread and compacted. The support is placed in a muffle furnace and calcined at 1450℃ for 5 hours. The calcined support is then polished to 300µm for later use. (3) After coating the oxygen electrode slurry onto the surface of the anode support obtained in step (2) above, put it into a tin furnace to dry it. Then, put the dried battery into a muffle furnace and calcine it at 1000°C for 2 hours. (4) Coat the surface of the battery obtained in step (3) with silver paste, attach silver wires to both sides of the battery, and then bake it in a tin furnace until dry. Finally, seal the battery with ceramic glue onto a ceramic tube and let it dry to obtain Ba 1-x K x (Co 0.7 Fe 0.3 ) 0.85 Ta 0.15 O 3-δ Solid oxide fuel cells using oxygen electrode materials.

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