High-temperature reversible solid oxide battery electrode material and preparation method and application thereof

Abstract

The invention discloses a high-temperature reversible solid oxide battery electrode material and a preparation method and application thereof. The chemical formula of the electrode material is La1-xCaxFe1-y-zCoyNizO3-delta, wherein x is more than or equal to 0.1 and less than or equal to 0.5, y is more than or equal to 0.1 and less than or equal to 0.3, z is more than or equal to 0.1 and less than or equal to 0.3, and delta is oxygen vacancy content and is 0-0.1; a sol-gel method is adopted for preparation. According to the invention, the collaborative design of three transition metals Fe-Co-Ni is introduced, so that the ionic conductivity and the electronic conductivity of the material are improved, the interface resistance is reduced by the dual-conductive material, and relatively high power output and relatively low polarization impedance are realized. After the material is compounded with GDC, the material serves as a reversible solid oxide battery anode material, the maximum output power at the working temperature of 800 DEG C can reach 1.60 W / cm < 2 >, the ohmic resistance is 0.11 ohm cm < 2 >, and when the material serves as an electrolytic tank and water is electrolyzed for hydrogen production, the corresponding electrolytic current density at 800 DEG C and 1.3 V is 2.18 A / cm < 2 >.

Description

Technical Field

[0001] The present invention relates to the technical field of solid oxide batteries, and in particular to a high-temperature reversible solid oxide battery electrode material and a preparation method and application thereof. Background Art

[0002] As the core device for efficient bidirectional conversion of electricity and hydrogen energy, the high-temperature reversible solid oxide cell (R-SOC) can flexibly switch between solid oxide fuel cell (SOFC) and electrolyzer (SOEC) modes, with an operating temperature of 600–900°C. In SOEC mode, water vapor or carbon dioxide is efficiently decomposed into high-value-added chemicals such as hydrogen and synthesis gas through electrochemical conversion, with system efficiency reaching 85-90%. This enables H2O / CO2 co-electrolysis, which is of great significance to achieving the "dual carbon" goal. Its anode material, as the site for catalyzing the oxygen evolution reaction at high temperature, must have high electron-ion mixed conductivity, excellent electrocatalytic activity, and long-term structural stability.

[0003] Traditional strontium-containing perovskite oxide materials (such as LSCF) have been considered ideal anode materials due to their high electronic conductivity and tunable oxygen vacancy concentration. However, the inherent defects of this type of material gradually become apparent during long-term high-temperature operation. For example, the Sr element inevitably migrates to the electrode / electrolyte interface at high temperatures, forming insulating SrO x The Sr / Co co-segregation can induce a perovskite phase transition, causing irreversible structural degradation and affecting the long-term stability of the battery. Therefore, it is urgent to develop new anode materials that combine high activity, anti-segregation properties, and controllable preparation processes. Summary of the Invention

[0004] One of the purposes of the present invention is to provide a high-temperature reversible solid oxide battery electrode material.

[0005] A second object of the present invention is to provide a method for preparing the above-mentioned high-temperature reversible solid oxide battery electrode material.

[0006] The third object of the present invention is to provide the use of the above-mentioned high-temperature reversible solid oxide battery electrode material.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a high-temperature reversible solid oxide battery electrode material, wherein the electrode material is a perovskite structure oxide with a chemical formula of La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ(LCFCN), where 0.1≤x≤0.5, 0.1≤y≤0.3, 0.1≤z≤0.3, δ is the oxygen vacancy content, δ = 0 to 0.1.

[0009] A second aspect of the present invention provides a method for preparing the above-mentioned high-temperature reversible solid oxide battery electrode material, comprising the following steps:

[0010] (1) According to the chemical formula La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ The stoichiometric ratios of La, Ca, Fe, Co and Ni in the mixture are accurately weighed: La(NO3)3·6H2O, Ca(NO3)2·4H2O, Fe(NO3)3·9H2O, Co(NO3)2·6H2O and Ni(NO3)2·6H2O, where 0.1≤x≤0.5, 0.1≤y≤0.3, 0.1≤z≤0.3, δ is the oxygen vacancy content, δ=0-0.1;

[0011] (2) adding the weighed nitrates to water in sequence, heating and stirring until dissolved to obtain solution A; then adding citric acid and ethylenediaminetetraacetic acid (EDTA) in sequence, adjusting the pH value with ammonia water, and stirring until the solution is clear to obtain solution B, at which the pH is between 7 and 8;

[0012] (3) heating the mixed solution B to evaporate water until a gel C is formed;

[0013] (4) drying the gel C to obtain a precursor, and grinding the precursor to obtain a powder D;

[0014] (5) calcining the powder D and cooling to obtain La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ Electrode material.

[0015] Preferably, in step (2), the molar ratio of metal ions: citric acid: ethylenediaminetetraacetic acid in solution A is 1:1.5:1.

[0016] Preferably, in step (3), the mixed solution B is heated and evaporated at 60-90°C.

[0017] Preferably, in step (4), the gel C is dried at 200-250° C. for 12 h.

[0018] Preferably, in step (4), the calcination system of the powder D is: heating from room temperature to 600°C at a heating rate of 3°C / min, keeping warm for 60 minutes, then heating to 800°C at a heating rate of 2°C / min, keeping warm for 300 minutes, and then cooling to 400°C at a cooling rate of 3°C / min and then cooling in the furnace.

[0019] A third aspect of the present invention provides use of the above-mentioned high-temperature reversible solid oxide battery electrode material in the preparation of a reversible solid oxide battery.

[0020] Furthermore, YSZ material was used as electrolyte and NiO-YSZ as cathode. 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ The slurry obtained by mixing and stirring the anode material and the binder after the material is compounded with the barrier layer GDC is coated on the surface of the electrolyte to prepare a reversible solid oxide battery.

[0021] Furthermore, when the reversible solid oxide battery is in operation, air is introduced into the anode and fuel gas is introduced into the cathode.

[0022] A fourth aspect of the present invention provides the use of the above-mentioned high-temperature reversible solid oxide battery electrode material in hydrogen production by water electrolysis.

[0023] The perovskite La in the present invention is used 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ After being compounded with GDC, it is used as the anode material of the reversible solid oxide battery. The working principle of the prepared reversible solid oxide battery is as follows: For the SOFC mode, first, when air is introduced into the anode side, O2 is catalytically dissociated into O 2- , the generated O 2- The fuel gas in the cathode, such as hydrogen and O 2- Under the action of the catalytic material, a reaction occurs to produce H2O. At the same time, electrons are transmitted through the external circuit to form current, thereby realizing the conversion of chemical energy into electrical energy. In the SOEC mode, taking water electrolysis as an example, when the external power supply applies voltage, the current flows from the anode to the cathode. H2O obtains electrons on the cathode surface and is reduced to produce H2 and O 2- . Then O 2- O2 migrates from the electrolyte to the anode side, where it undergoes oxidation reaction to generate O2.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) The present invention replaces the Sr element in traditional Sr-containing perovskite anode materials with Ca, forming an Sr-free perovskite main structure. This fundamentally eliminates the fundamental cause of the irreversible segregation of Sr at high temperatures, thereby effectively avoiding the resulting material performance degradation problem.

[0026] (2) The present invention introduces the synergistic design of three transition metals, Fe-Co-Ni, in which Fe and Co serve as the substrate to jointly maintain the high oxygen vacancy concentration of the material, ensuring excellent ionic conductivity; while the specific proportion of Ni doping significantly improves the electronic conductivity and anti-carbon deposition ability of the material. The synergistic effect of Fe-Co-Ni is the core guarantee for the material to achieve high performance. At the same time, Ca element is used to completely replace Sr, combined with Ni 2+ Co-doping optimizes lattice stability, precisely matches the thermal expansion coefficient to YSZ, and combines with the sol-gel method to achieve a nano-homogeneous structure, completely resolving the performance degradation problem caused by segregation and providing a revolutionary solution for SOECs that combines high activity with long life.

[0027] (3) La in the present invention 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ After the perovskite is compounded with GDC, it is used as the anode material of the reversible solid oxide battery. This electrode material has good structural stability and can conduct electrons and oxygen ions at the same time. Such a dual conductive material reduces the interface resistance, achieves higher power output and lower polarization impedance.

[0028] (4) La in the present invention 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The composite of perovskite and GDC as anode material for reversible solid oxide batteries can achieve a maximum output power of 1.60 W / cm at an operating temperature of 800 °C. 2 , ohmic impedance is 0.11Ωcm 2 When used as an electrolytic cell, the electrolysis current density at 800°C and 1.3V is 2.18A / cm 2 . BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 La prepared by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O3-δ XRD pattern of perovskite material;

[0030] Figure 2 La prepared by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ SEM images of perovskite materials;

[0031] Figure 3 La prepared by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The impedance diagram of the full cell after the perovskite material is composited with GDC as the anode of the high-temperature reversible solid oxide battery under hydrogen;

[0032] Figure 4 La prepared by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ IVP curve of a full cell in hydrogen atmosphere after the perovskite material is composited with GDC as the anode of a high-temperature reversible solid oxide battery;

[0033] Figure 5 La prepared by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The voltage-current density curve of the perovskite material composited with GDC when used as a high-temperature reversible solid oxide cell to electrolyze water and produce hydrogen. DETAILED DESCRIPTION

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0035] Example 1: Preparation of La by sol-gel method 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ

[0036] According to the chemical formula La 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni0.1 O 3-δ The stoichiometric ratios of the elements in the reaction mixture were as follows: La(NO3)3·6H2O: 15.3 g, Ca(NO3)2·4H2O: 3.6 g, Fe(NO3)3·9H2O: 16.1 g, Co(NO3)2·6H2O: 1.5 g, Ni(NO3)2·6H2O: 1.5 g, citric acid: 28.9 g, and EDTA: 29.4 g.

[0037] First, each metal nitrate was dissolved in a flask containing 200 mL of pure water in turn and stirred in a 40°C water bath; then citric acid and EDTA powder were added and dissolved therein, and ammonia solution was added dropwise with a separatory funnel until the pH of the solution was between 7 and 8. The mixed solution was continued to be stirred in a 90°C oil bath for 10 hours to evaporate the water; the obtained wine-red transparent sol was transferred to an oven and dried at 200°C for 12 hours to obtain a solid precursor; the gel was transferred to a muffle furnace and calcined for a certain period of time (heating from room temperature to 600°C at 3°C / min, keeping at 600°C for 60 minutes, then heating to 800°C at 2°C / min and keeping at this temperature for 300 minutes), then cooled to 400°C at a cooling rate of 3°C / min, cooled with the furnace, taken out and ground to obtain a powdered sample.

[0038] See also Figure 1 , is La prepared in this example 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The X-ray powder diffraction pattern showed that no other peaks appeared. 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ It is a pure physical phase.

[0039] See also Figure 2 , which is the SEM (scanning electron microscope) image of the sample prepared in this example; it can be seen that the sample is well crystallized and the particles are uniform.

[0040] Example 2: Preparation of La by sol-gel method 0.9 Ca 0.1 Fe 0.7 Co 0.2 Ni 0.1 O 3-δ

[0041] According to the chemical formula La 0.9 Ca 0.1 Fe 0.7 Co 0.2 Ni0.1 O 3-δ The stoichiometric ratios of the elements in the reaction mixture were as follows: La(NO3)3·6H2O: 19.7 g, Ca(NO3)2·4H2O: 1.2 g, Fe(NO3)3·9H2O: 14.3 g, Co(NO3)2·6H2O: 3.0 g, Ni(NO3)2·6H2O: 1.5 g, citric acid: 28.9 g, and EDTA: 29.4 g.

[0042] First, each metal nitrate was dissolved in a flask containing 200 mL of pure water in turn and stirred in a 40°C water bath; then citric acid and EDTA powder were added and dissolved therein, and ammonia solution was added dropwise with a separatory funnel until the pH of the solution was between 7 and 8. The mixed solution was continued to be stirred in a 90°C oil bath for 10 hours to evaporate the water; the obtained wine-red transparent sol was transferred to an oven and dried at 200°C for 12 hours to obtain a solid precursor; the gel was transferred to a muffle furnace and calcined for a certain period of time (heating from room temperature to 600°C at 3°C / min, keeping at 600°C for 60 minutes, then heating to 800°C at 2°C / min and keeping at this temperature for 300 minutes), then cooled to 400°C at a cooling rate of 3°C / min, cooled with the furnace, taken out and ground to obtain a powdered sample.

[0043] Example 3: Preparation of La by sol-gel method 0.5 Ca 0.5 Fe 0.4 Co 0.3 Ni 0.3 O 3-δ

[0044] According to the chemical formula La 0.5 Ca 0.5 Fe 0.4 Co 0.3 Ni 0.3 O 3-δ The stoichiometric ratios of the elements in the reaction mixture were as follows: La(NO3)3·6H2O: 10.9 g, Ca(NO3)2·4H2O: 6.0 g, Fe(NO3)3·9H2O: 8.2 g, Co(NO3)2·6H2O: 4.5 g, Ni(NO3)2·6H2O: 4.4 g, citric acid: 28.9 g, and EDTA: 29.4 g.

[0045] First, each metal nitrate was dissolved in a flask containing 200 mL of pure water in turn and stirred in a 40°C water bath; then citric acid and EDTA powder were added and dissolved therein, and ammonia solution was added dropwise with a separatory funnel until the pH of the solution was between 7 and 8. The mixed solution was continued to be stirred in a 90°C oil bath for 10 hours to evaporate the water; the obtained wine-red transparent sol was transferred to an oven and dried at 200°C for 12 hours to obtain a solid precursor; the gel was transferred to a muffle furnace and calcined for a certain period of time (heating from room temperature to 600°C at 3°C / min, keeping at 600°C for 60 minutes, then heating to 800°C at 2°C / min and keeping at this temperature for 300 minutes), then cooled to 400°C at a cooling rate of 3°C / min, cooled with the furnace, taken out and ground to obtain a powdered sample.

[0046] Example 4

[0047] La prepared in Example 1 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The reversible solid oxide battery is prepared from perovskite materials. The specific preparation process is as follows: La 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ After the perovskite material is compounded with GDC, it is used as the anode of the reversible solid oxide battery, with YSZ as the electrolyte material and NiO-YSZ as the cathode support.

[0048] Weigh La and 0.6 Ca 0.4 Fe 0.8 Co 0.1 Ni 0.1 O 3-δ The material powder and GDC material powder are then placed in a mortar, and a 40% ethyl cellulose terpineol solvent (the mass ratio of ethyl cellulose to terpineol is 1:10) is added. The mixture is ground for 1 hour to obtain a composite anode slurry. The prepared composite anode slurry is applied to one side of the YSZ electrolyte sheet twice. After the first coat, the sheet is placed in an 80°C oven and dried before the second coat is applied. After thorough drying, the sheet is placed in a 950°C muffle furnace and calcined for 2 hours. Platinum slurry is applied to both electrodes after calcination. After the platinum slurry is completely dry, a reversible solid oxide battery is obtained.

[0049] Air was passed through the anode side of the reversible solid oxide cell prepared in Example 2 at 100 mL / min, and hydrogen was used as the fuel gas at 40 mL / min. The impedance at 800°C, 750°C, and 700°C, and the maximum power density at 800°C, 750°C, and 700°C were recorded. The results are shown in FIG. Figure 3 、 Figure 4 shown.

[0050] Depend on Figure 3 It can be seen that the ohmic impedance of the reversible solid oxide battery with LCFCN-GDC composite material as electrode can reach 0.11, 0.15, and 0.22Ωcm at 800℃, 750℃, and 700℃, respectively. 2 .

[0051] Depend on Figure 4 It can be seen that the maximum power density of the reversible solid oxide battery with LCFCN-GDC composite material as electrode can reach 1.60, 1.16 and 0.73 W / cm at 800℃, 750℃ and 700℃ respectively. 2 .

[0052] Example 3

[0053] Hydrogen with water (50 mL / min 90% H2O + 10% H2) was introduced into the fuel gas side of the reversible solid oxide cell prepared in Example 2 to make it an electrolytic cell. Static air was used as the oxidant. The maximum current density was recorded at 800°C, 750°C, and 700°C, respectively. The results are shown in FIG. Figure 5 shown.

[0054] Depend on Figure 5 It can be seen that the maximum current density of the reversible solid oxide battery with LCFNC-GDC composite material as electrode at a constant voltage of 1.3V at 800℃, 750℃, and 700℃ can reach 2.18, 1.46, and 0.84A / cm 2 .

[0055] The foregoing description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by any person skilled in the art within the technical scope disclosed herein and within the spirit and principles of the present invention shall be covered by the scope of protection of the present invention. In addition, the terms "first," "second," "third," etc. are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A high-temperature reversible solid oxide battery electrode material, wherein the electrode material is a perovskite structure oxide, characterized in that: The chemical formula of the electrode material is La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ , where 0.1≤x≤0.5, 0.1≤y≤0.3, 0.1≤z≤0.3, δ is the oxygen vacancy content, δ = 0 ~ 0.

1.

2. A method for preparing a high-temperature reversible solid oxide battery electrode material according to claim 1, characterized in that: The following steps are involved: (1) According to the chemical formula La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ The stoichiometric ratios of La, Ca, Fe, Co and Ni in the mixture are accurately weighed: La(NO3)3·6H2O, Ca(NO3)2·4H2O, Fe(NO3)3·9H2O, Co(NO3)2·6H2O and Ni(NO3)2·6H2O, where 0.1≤x≤0.5, 0.1≤y≤0.3, 0.1≤z≤0.3, δ is the oxygen vacancy content, δ=0-0.1; (2) Weighed nitrates were added to water in sequence, heated and stirred until dissolved to obtain solution A; citric acid and ethylenediaminetetraacetic acid were then added in sequence, the pH value was adjusted with ammonia water, and stirred until the solution was clear to obtain solution B, at which point the pH was between 7 and 8; (3) heating the mixed solution B to evaporate water until a gel C is formed; (4) drying the gel C to obtain a precursor, and grinding the precursor to obtain a powder D; (5) calcining the powder D and cooling to obtain La 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ Electrode material.

3. The method for preparing a high-temperature reversible solid oxide battery electrode material according to claim 2, characterized in that: In step (2), the molar ratio of metal ions: citric acid: ethylenediaminetetraacetic acid in solution A is 1:1.5:

1.

4. The method for preparing a high-temperature reversible solid oxide battery electrode material according to claim 2, wherein: In step (3), the mixed solution B is heated and evaporated at 60-90°C.

5. The method for preparing a high-temperature reversible solid oxide battery electrode material according to claim 2, characterized in that: In step (4), the gel C is dried at 200-250° C. for 12 h.

6. The method for preparing a high-temperature reversible solid oxide battery electrode material according to claim 2, characterized in that: In step (4), the calcination system of the powder D is as follows: heating from room temperature to 600°C at a heating rate of 3°C / min, keeping warm for 60 minutes, then heating to 800°C at a heating rate of 2°C / min, keeping warm for 300 minutes, and then cooling to 400°C at a cooling rate of 3°C / min and then cooling in the furnace.

7. Use of the high-temperature reversible solid oxide battery electrode material according to claim 1 in the preparation of a reversible solid oxide battery.

8. The use according to claim 7, characterized in that YSZ material is used as electrolyte and NiO-YSZ is used as cathode. 1-x Ca x Fe 1-y-z Co y Ni z O 3-δ The slurry obtained by mixing and stirring the anode material, binder and graphite after the material is compounded with the barrier layer GDC is coated on one side of the electrolyte sheet to prepare a reversible solid oxide battery.

9. The use according to claim 8, characterized in that When the reversible solid oxide battery is in operation, air is introduced into the anode and fuel gas is introduced into the cathode.

10. Use of the high-temperature reversible solid oxide battery electrode material according to claim 1 in hydrogen production by water electrolysis.

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