CN113839054B - A kind of reversible proton ceramic battery electrode material and its preparation method and application - Google Patents

Abstract

The invention relates to a high-performance proton ceramic fuel cell/electrolytic cell (PCFC/PCEC) reversible electrode material composition and a preparation method thereof, belonging to the technical field of solid oxide reversible cells. The electrode material has a two-phase structure consisting of a cubic structure and a honeycomb-like hexahedral structure. Compared with the air electrode of the traditional solid oxide fuel cell, the double-phase electrode has excellent proton conductivity and rapid hydration capability on the premise of having oxygen ion and electron conductivity. Thus allowing the electrode material to have excellent electrochemical properties in both PCFC and PCEC modes.

Description

A kind of reversible proton ceramic battery electrode material and its preparation method and application

technical field

The invention relates to a high-performance reversible proton ceramic battery electrode material composition and its preparation method and application, belonging to the technical field of solid oxide reversible batteries.

Background technique

With the rapid development of my country's economy, the contradiction between energy supply and demand and the environmental pollution caused by inefficient use of energy are becoming more and more serious. The current main energy source is non-renewable fossil energy such as petroleum, coal and natural gas, and the inefficient combustion of these carbon-containing compounds is the main cause of air pollution. On the other hand, the turbulent and unstable factors in the international community also have a huge impact on the supply of external energy. Therefore, the development of new energy systems and the improvement of energy utilization are very important to ensure the sustainable development of our country's economy and society and improve our country's energy security.

A proton ceramic electrochemical cell (PCEC) is a proton conductor-based solid oxide cell that can work in a reversible manner to store renewable energy using water electrolysis to generate hydrogen, which can then be converted back into electricity in fuel cell mode. The application of PCEC demonstrates the uniqueness of combining the dual functions of energy storage and distributed generation by integrating the balancing of PCEC and the plant into one system. With remarkable progress in the past decade in the development of solid-state proton conductors and associated electrochemical cells (fuel cells and electrolyzers), PCEC represents a promising technology aimed at achieving low-cost Energy storage and conversion at low temperatures attract advantages such as high efficiency, longer system durability and cheaper materials. However, large-scale deployment of PCECs remains elusive due to sluggish electrode kinetics and shortened lifetimes of materials and interfaces at moderate temperatures, due to severe constraints in the development of highly active and stable electrodes.

In the prior art, research has been conducted towards the development of new oxygen electrode materials to alleviate these issues, which are the largest contributors to the performance degradation and efficiency loss of existing PCECs. For example: CN110494595A discloses an anode material applied to electrolysis of water, which has a structure such as BaCo _1-x Ti _x O _3-δ : Co ₃ O ₄ , but it can only be applied to anode materials and does not Has application in the ORR process. Currently, both water oxidation reaction (WOR) and oxygen reduction reaction (ORR) in mixed ion- and electron-conducting (MIEC) electrodes are strictly confined to the three-phase boundary (TPB) where ions, electrons, and gas meet. Therefore, in PCEC systems, it is highly desirable to introduce proton conduction into MIEC materials to formulate triple conducting oxides (TCOs), i.e., electrons, oxygen ions, and protons, to extend the TPB from the electrolyte/electrode interface into the electrode body. Despite these advantages, few TCO candidates have been produced so far due to the difficulty in generating sufficient proton-conducting defects under the prerequisite of available readily hydratable oxygen, and despite the rapid development of PCEC technology, there are still some difficulties to be solved, High performance, high stability and low cost are still the main focus of current research and development.

Contents of the invention

This patent is aimed at the research and development of triple conductive oxide electrode materials, which enables TCO to obtain higher performance and better stability in both PCFC and PCEC modes. The invention provides a high-performance electrode material for a proton conductor fuel cell/electrolytic cell, which has a dual-phase structure composed of a cubic structure and a honeycomb-like hexahedron structure, and improves the performance of the proton conductor air electrode. The prepared air electrode has small polarization resistance, high proton conductivity, etc., so that the cathode material can be applied to medium and low temperature proton conductor solid oxide fuel cells, and has excellent performance. At the same time, the electrode has a very high content of oxygen vacancies, which provides more sites for hydration reactions, and good hydrophilicity and fast hydration kinetics, making it also have excellent electrochemical performance in proton conductor electrolytic cells.

The first object of the present invention provides:

A solid oxide air electrode material, the molecular formula is: ABO ₃ , wherein the A-site element is selected from any one or several of Ba, Sc, Sm, and Pr; the B-site element is selected from any one of Co, Fe, and Ti or several; and, the electrode material has a dual-phase structure composed of a cubic structure and a honeycomb-like hexahedral structure.

In one embodiment, the A-site element is selected from Ba and Sc.

In one embodiment, the B-site element is selected from Co and Fe.

In one embodiment, the molecular formula is Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ (BSCF-1.5), where δ represents the oxygen vacancy content.

Second object of the present invention provides:

The preparation method of the above-mentioned solid oxide air electrode material includes the following steps: according to the stoichiometric ratio, it is prepared by a sol-gel method.

In one embodiment, barium nitrate, strontium nitrate, cobalt nitrate, and iron nitrate are prepared by a sol-gel method according to the stoichiometric ratio in the molecular formula.

In one embodiment, the following steps are included: first mix an appropriate amount of deionized water with Ba(NO ₃ ) ₂ , Sr(NO ₃ ) ₂ , Co(NO ₃ ) ₂ ·6H ₂ O, Fe(NO ₃ ) ₃ ·9H ₂ O mixed, heated and stirred and dissolved; after all dissolved, add ethylenediaminetetraacetic acid and citric acid monohydrate, then add ammonia water dropwise until the pH of the solution is between 7 and 8, and volatilize the water under the condition of heating and stirring to obtain Gel-like substance; drying the gel-like substance in an oven to obtain an electrode material precursor, and then roasting the precursor in a muffle furnace to obtain the required electrode material.

In one embodiment, the total molar ratio of EDTA and citric acid monohydrate to Ba, Sr, Co, Fe is 1.5-2.5:0.5-1.5:0.5-1.5.

In one embodiment, the condition of the drying process is 200-300° C. for 5-8 hours.

In one embodiment, the calcination parameter is 950-1050° C. for 3-7 hours.

A third object of the present invention provides:

Use of the above-mentioned solid oxide air electrode material in a fuel cell.

In one embodiment, the use refers to the use as a proton conductor cathode.

In one embodiment, the electrolyte is BaZr _0.1 Ce _0.7 Y _0.1 Yb _0.1 O _3-δ .

In one embodiment, the anode material is a composite anode composed of NiO and BaZr _0.1 Ce _0.7 Y _0.1 Yb _0.1 O _3-δ (BZCYYb).

In one embodiment, the mass ratio of NiO, electrolyte and soluble starch in the composite anode is 6.5:3.5:1.

In one embodiment, the electrochemical performance of the electrode material is also evaluated in the use.

In one embodiment, the use refers to improving electronic conductivity, proton conductivity, output power or battery stability.

A fourth object of the present invention provides:

Use of the above-mentioned solid oxide air electrode material in a proton ceramic electrolytic cell.

In one embodiment, the use refers to the use as a proton conductor air electrode.

In one embodiment, the electrolyte is BaZr _0.1 Ce _0.7 Y _0.1 Yb _0.1 O _3-δ .

In one embodiment, the hydrogen electrode material is a composite electrode composed of NiO and BaZr _0.1 Ce _0.7 Y _0.1 Yb _0.1 O _3-δ (BZCYYb).

In one embodiment, the mass ratio of NiO, electrolyte and soluble starch in the composite electrode is 6.5:3.5:1.

In one embodiment, the electrochemical performance of the air electrode material is also evaluated in the use.

In one embodiment, the use refers to enhancing electronic conductivity, hydration kinetics, output current, hydrogen production, and Faradaic efficiency.

Beneficial effect

The high-performance reversible solid oxide electrode material involved in the present invention is prepared by a sol-gel method and has the following effects:

(1) The simplicity of the synthesis method

Biphasic electrode materials with different unique phase structures synthesized by a simple sol-gel one-step method: Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ (BSCF-1.5), which has a cubic structure and a honeycomb-like hexagonal structure, and the synthesis method is simple and efficient.

(2) Material uniqueness

BSCF-1.5 serves as a unique dual-phase material with both ORR and OER activities due to its ultra-high oxygen vacancy content and hydration properties.

The cubic phase improves the stability and electronic conductivity of the material, and the honeycomb-like hexagonal phase has excellent proton transport and ion bulk phase diffusion capabilities.

Dual-phase materials have optimized ion and electron transport paths for faster reaction rates in both electrolysis and fuel cell modes.

(3) Excellent performance

BSCF-1.5 has a high performance of 1220mW cm ^-2 at 650°C in fuel cell mode, and a current density of -1333mA cm ^-2 at 1.3V in electrolysis mode.

Description of drawings

Figure 1 is the XRD pattern of BSCF-1.5 at room temperature;

Figure 2 is the XRD pattern of BSCF-1.5 treated at 650°C for 100 hours;

Figure 3 is the XPS characterization spectrum; among them, (a) Co 2p _3/2 , Ba3d _5/2 X-ray photoelectron spectra of BSCF-1, BSCF-1.5 and BSCF-2 oxides, (b) Fe 2p _3/2 X-ray photoelectron spectroscopy.

Figure 4 is the electronic conductivity of BSCF-1.5;

Fig. 5 is the Arrhenius diagram of Dchem and kchem of BSCF-1 and BSCF-1.5 oxides obtained by conductance relaxation method.

Figure 6 is the output power performance curve of Ni-BZCYYb|BZCYYb|BSCF-1.5 single cell in the temperature range of 500-650 °C;

Fig. 7 is the ECR curve of BSCF-1 oxide when the air changes pH2O=0.03atm from dry state.

Fig. 8 is the N adsorption _- desorption curve of sample;

Fig. 9 is an EIS curve of an oxygen reduction electrode of a symmetrical battery at 500-700°C. (a) BSCF-1, (b) BSCF-1.5, and (c) BSCF-2 oxygen reduction electrodes;

Figure 10 is a comparison of the activation energy of BSCF-1.5 prepared by physical mixing and BSCF-1.5 prepared by one-step sol-gel method.

Figure 11 shows the impedance of Ni-BZCYYb|BZCYYb|BSCF-1.5 single cell in the temperature range of 500-650°C;

Figure 12 is the topography of Ni-BZCYYb|BZCYYb|BSCF-1.5 single cell after 2 hours of testing;

Figure 13 is the impedance of BSCF-1.5|BZCYYb|BSCF-1.5 symmetrical battery in the temperature range of 500-700°C;

Figure 14 shows the impedance stability of BSCF-1.5|BZCYYb|BSCF-1.5 symmetrical battery at 550°C;

Figure 15 is the performance curve of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolytic cell electrolyzing water in the temperature range of 500-600°C;

Figure 16 shows the hydrogen production of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolytic cell at 600°C with different water pressures;

Figure 17 is the Faraday efficiency of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolysis cell at 600°C with different water pressures;

Figure 18 shows the performance of BSCF-1 and BSCF-2 in PCECs mode.

Detailed ways

The invention provides a high-performance air electrode material Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ (BSCF-1.5) of a proton conductor fuel cell/electrolyzer and its preparation method and application, wherein δ represents the content of oxygen vacancies, The invention belongs to the technical field of reversible solid oxide batteries. A biphasic electrode BSCF-1.5 was synthesized by one-step sol-gel method, in which the two phase compositions were Ba _0.5 Sr _0.5 Co _0.8 Fe _0.2 O _3-δ (BSCF-1) and BaSrCo _0.8 Fe _0.2 O _4-δ (BSCF-2 ). Among them, BSCF-1 provides higher electronic conductivity, and the high content of Co can better maintain the proton conductivity of the parent material double perovskite structure, and make the material have excellent electrical conductivity and catalytic activity; while Fe Elements can also improve the electrical conductivity and catalytic activity of the host material, and on the other hand, further improve the structure and electrochemical stability of the material due to its relatively large ionic radius. However, due to the honeycomb-like hexagonal structure, BSCF-2 provides a large amount of oxygen vacancies, and the high proportion of Ba, Sr content significantly improves the hydrophilicity of the material, so BSCF-2 provides more hydration reaction sites. , and fast proton diffusion and transport capabilities.

Since the synergistic effect of BSCF-1 and BSCF-2 provides a good reversible guarantee for BSCF-1.5, it can obtain excellent performance in both proton ceramic fuel cell and electrolytic cell applications. In PCFC mode, the corresponding single cell can obtain a maximum output power of 1218mW cm ^-2 at 650°C; at 600°C in PCEC mode, electrolysis of H ₂ O can obtain -1.33A cm ^-2 at 1.3V the maximum current density. The invention develops a high-performance reversible electrode material and a preparation method, which greatly improves the electrochemical performance of proton ceramic fuel cells and electrolytic cells.

Preparation of low temperature proton ceramic fuel cell/electrolyzer air electrode material Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ in Example 1

(1) Weigh 9.8007g of barium nitrate, 7.9362g of strontium nitrate, 11.6412g of cobalt nitrate, 4.04g of iron nitrate, add a small amount of deionized water to dissolve. Weigh 11.7 g of EDTA and 16.8 g of citric acid hydrate as a complexing agent and dissolve them in deionized water at a molar ratio of EDTA: citric acid monohydrate: total metal ions of 1:2:1.

(2) After adding the solution containing complexing agent to the solution containing metal ions, add an appropriate amount of ammonia water dropwise to bring the pH of the solution to 7-8, and then stir under the condition of magnetic stirring to completely evaporate the water to obtain a gel substance.

(3) The gel-like substance was placed in an oven and calcined at 250° C. for 5 hours to obtain the desired foamy precursor.

(4) The precursor is placed in a high-temperature muffle furnace and calcined at 1000° C. for 5 hours to obtain the desired cathode powder.

Embodiment 2 Preparation of symmetrical battery

(1) Weigh 1g of the cathode powder Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ prepared in Example 1, 10ml of isopropanol, 2ml of ethylene glycol, and 0.8ml of glycerin into a high-energy In ball milling, after ball milling under the condition of 400r/min for 30min, the required cathode slurry was obtained after being transferred to the strain bottle with a straw.

(2) Place the prepared BZCYYb electrolyte on a heating table to preheat at 200°C, use a spray gun to spray the prepared cathode slurry evenly on both sides of the electrolyte under the push of an inert gas, and wait until the liquid is completely volatilized, The sprayed electrolyte was placed in a high-temperature muffle furnace and calcined at 1000°C for 2 hours to prepare the required symmetrical battery, which was used for the test of the polarization resistance of the cathode material in the temperature range of 500-700°C. The polarization resistance of the battery at 700°C is 0.04Ωcm ² .

The preparation of embodiment 3 single cell

(1) Weigh 1g of the cathode powder Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ prepared in Example 1, 10ml of isopropanol, 2ml of ethylene glycol, and 0.8ml of glycerin into a high-energy In ball milling, after ball milling under the condition of 400r/min for 30min, the required cathode slurry was obtained after being transferred to the strain bottle with a straw.

(2) Place the prepared dry-pressed battery sheet on a heating table to preheat at 200°C, and use a spray gun to spray the prepared cathode slurry evenly on the electrolyte surface of the dry-pressed sheet under the push of an inert gas. After the liquid is completely volatilized, the sprayed dry-pressed battery is placed in a high-temperature muffle furnace and calcined at 1000°C for 2 hours to obtain the desired symmetrical battery, which is used to measure the polarization impedance of the cathode material within the temperature range of 500-650°C. test.

Characterization results

1. XRD characterization

Figure 1 shows Ba _0.5 Sr _0.5 Co _0.8 Fe _0.2 O _3-δ (BSCF-1), Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ (BSCF-1.5) and BaSrCo _0.8 Fe _0.2 O _4-δ (BSCF -2) Powder X-ray Diffraction (XRD) pattern. It can be seen that both BSCF-1 and BSCF-2 powders obtained a single phase, and no detectable impurities were observed, indicating that phase-pure powders have been successfully prepared. Through XRD refinement, it can be obtained that BSCF-1 is a cubic perovskite, while BSCF-2 is a unique hexagonal structure composed of a honeycomb network. It can be seen from the X-ray diffraction pattern that the peak position of BSCF-1.5 is exactly BSCF- 1 and BSCF-2, thus indicating that BSCF-1.5 synthesized by a simple sol-gel method is a biphasic material.

Figure 2 is the XRD pattern of BSCF-1.5 calcined at 650°C for 100 hours. It can be seen from the figure that BSCF-1.5 still maintains a good dual-phase structure, no other impurity phases are formed, and both phases maintain a stable phase structure .

2. XPS characterization

As shown in Fig. 3, the Co ³⁺ content of the three samples at room temperature is the lowest at 77.3% in BSCF-2, while the Co ³⁺ content in BSCF-1, BSCF-1.5 is 60.8% and 63%, respectively. On the other hand, the Fe2p spectrum of the sample in the figure can be divided into three bands, corresponding to Fe ²⁺ , Fe ³⁺ and Fe ⁴⁺ , respectively. The contents of Fe ²⁺ in BSCF-1, BSCF-1.5 and BSCF-2 were 70%, 61.8% and 56.9%, the contents of Fe ³⁺ were 23.4%, 25% and 16.1%, and the contents of Fe ⁴⁺ were 6.6%, 13.2% and 27%. Obviously, the average valence of B sites in BSCF-1.5 is in the middle of BSCF-1 and BSCF-2 samples, resulting in an intermediate value of oxygen vacancy concentration at room temperature.

3. Conductivity Characterization

Figure 4 is the electrical conductivity of the BSCF-1.5 composite and conventional BSCF-1 and BSCF-2 measured in air between 300°C and 800°C. The conductivity of BSCF-1.5 is between 5-32Scm ^-1 , the conductivity of BSCF-1.5 is slightly lower than BSCF-1 (21-75Scm ^-1 ) but higher than BSCF-2 (0.1-3Scm ^-1 ). The conductivity of BSCF-1 and BSCF-1.5 meets the basic requirements of PCFC cathode.

4. Oxygen diffusivity characterization

Figure 5. By measuring the oxygen surface exchange coefficient (kchem) and oxygen volume diffusivity (Dchem) using a ceramic sample with density >97%, BSCF-1.5 also shows an extremely high oxygen diffusivity. At each temperature, the Dchem and kchem values of BSCF-1.5 are much higher than those of BSCF-1. Taking 700°C as an example, the Dchem and kchem values of BSCF-1.5 are 2.51×10 ^-3 and 4.69×10 ^-3 , however BSCF-1 are 2.27×10 ^-4 and 4.88×10 ^-4 , respectively. Dchem and kchem increased by about 8.24 and 8.61 times, respectively. These Dchem and kchem values are the highest for known perovskite oxides and are comparable to those of BSCF and other MIECs. The enhanced oxygen ion conductivity endows the electrode with good charge transfer capability in ORR.

Figure 6 shows the ECR curve of BSCF-1 oxide when the air changes pH2O=0.03atm from a dry state. At a temperature of 500°C, the Dchem and kchem values of BSCF-1.5 and BSCF-1 still maintain the same difference, but the impedance The test shows that the difference decreases, indicating that the influence of water adsorption on impedance cannot be ignored as the temperature decreases. Figure 7 shows the N ₂ adsorption-desorption curves of the samples. It can be seen that the specific surface area of BSCF-1, BSCF-1.5 and BSCF-2 increases sequentially, but after 2 h of humid air treatment, BSCF-1.5 has the highest specific surface area .

5. Output power characterization

Fig. 8 is the typical IV and IP curves of the output power of Ni-BZCYYb|BZCYYb|BSCF-1.5 single cell in the temperature range of 500-650 °C. The power densities of BSCF-1.5 cathode single cells increase monotonically with temperature, in the same pattern as other PCFCs, at 1220, 850, 610 and 410 mW cm ^-2 at 650 to 500 °C. At 650°C, 550°C, and 500°C, the open-circuit voltage (OCV) of BSCF-1.5 was 1.036V, 1.070V, and 1.097V, which were close to the theoretical OCV values at these temperatures, showing good single-cell hermeticity and negligible Electrolyte electron leakage.

6. Electrochemical Impedance Analysis

Areas a, b, and c of Figure 9 show the electrochemical impedance spectra of BSCF-1, BSCF-1.5, and BSCF-2 under humid air conditions, respectively. The impedances of BSCF-1.5 are 0.04, 0.082, 0.24, 0.75 and 2.8 Ωcm at 700, 650, 600, 550 and 500°C, respectively. Significantly smaller than samples BSCF-1 and BSCF-2. For a single cell with BSCF-1.5 as the cathode, the polarization impedance only accounts for 10% to 20% of the total ASR of the single cell, while the ohmic impedance is jointly determined by the thickness of the BZCYYb electrolyte and the cell preparation process. Ohmic impedance becomes the dominant resistance during operation. At the same time, it can be seen that the polarization impedance is significantly lower than that of the current mainstream proton ceramic fuel cell cathode, which has certain commercial application prospects.

7. Activation energy test

Figure 10 compares the difference between BSCF-1.5 prepared by physical mixing and one-step sol-gel preparation. BSCF-1 and BSCF-2 are physically mixed at a molar ratio of 1:1 to prepare BSCF-1.5(PM) powder. The symmetric cell with BSCF-1.5 as electrode prepared by one-step method has lower activation energy under the same conditions. It is mainly attributed to the more uniform mixing and smaller particle size prepared by the one-step method, which is conducive to the electrochemical reaction.

Figure 11 shows the cross-sectional image shape of a single cell comprising Ni-BZCYYb composite anode, dense BZCYYb electrolyte, and porous BSCF-1.5 cathode after performance testing. It can be clearly seen from the figure that the adhesion between the BSCF-1.5 cathode and the BCZYYb electrolyte is still tight, which also proves the reliability of the single-cell performance test results.

8. Impedance Characterization

Figure 13 is the impedance of BSCF-1.5|BZCYYb|BSCF-1.5 symmetrical battery in the temperature range of 500-700 ℃. It can be seen from the figure that the polarization impedance of BSCF-1.5 is at 700, 650, 600, 550 and 500 ℃ are 0.04, 0.082, 0.24, 0.75 and 2.8Ωcm ^-2 .

Figure 14 shows the impedance stability of BSCF-1.5|BZCYYb|BSCF-1.5 symmetrical battery at 550°C; after 420h of symmetrical battery stability test, the impedance did not increase significantly, indicating that BSCF-1.5 has good electrochemical stability.

9. Electrolytic performance characterization

Figure 15 is the performance curve of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolysis cell in the temperature range of 500-600 ℃; the corresponding current density of BSCF-1.5 at a voltage of 1.3V is -1333, -844, -466mA cm ^-2 are 600, 550 and 500°C, respectively. The excellent electrolytic performance is mainly attributed to the high oxygen vacancies and fast hydration reaction, as well as the excellent water storage of BSCF-1.5.

Figure 14 shows the hydrogen production of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolysis cell at 600°C with different water pressures; under the condition of 600°C, the hydrogen production of 10%, 20%, and 30% different water pressures was tested , by changing the current density, it is found that with the increase of the current density, the amount of hydrogen produced increases. At the same current density, the water pressure is proportional to the hydrogen production, which is consistent with the previous test conclusions. When the water pressure is 30%, the hydrogen production is close to the theory. value.

Figure 16 shows the Faraday efficiency of Ni-BZCYYb|BZCYYb|BSCF-1.5 electrolysis cell at 600°C with different water pressures; it can be seen from the figure that the Faraday efficiency is also close to 100% under the condition of 30% water pressure, which shows that our electrode materials and the overall electrolysis cell The preparation process is excellent, and the air electrode also has excellent electrochemical performance.

Figure 18 shows the performance of BSCF-1 and BSCF-2 in PCECs mode. It can be seen that BSCF-1.5 material shows better Faraday efficiency and current density than BSCF-1 and BSCF-2 material.

In summary, it can be seen that compared with the traditional solid oxide fuel cell air electrode, the dual-phase electrode has excellent proton conductivity and rapid hydration ability on the premise of having oxygen ion and electron conductivity. Therefore, BSCF-1.5 has excellent electrochemical performance in both PCFC and PCEC modes. When the proton conductor electrolyte BaZr _0.1 Ce _0.7 Y _0.1 Yb _0.1 O _3-δ (BZCYYb) and the hydrogen electrode composed of 65% NiO and 35% BZCYYb by mass fraction, the corresponding single cell at 650 ° C, in PCFC In this mode, the battery can obtain a maximum output power of 1218mW cm ^-2 ; at 600°C in PCEC mode, H ₂ O can be electrolyzed, and a maximum current density of -1.33A cm ^-2 can be obtained at 1.3V. The invention develops a high-performance reversible electrode material and a preparation method, which greatly improves the electrochemical performance of proton ceramic fuel cells and electrolytic cells.

Claims (2)

1. a kind of solid oxide air electrode material is used in the purposes of proton ceramic electrolyzer and fuel cell, it is characterized in that, solid oxide air electrode material molecular formula is Ba _0.75 Sr _0.75 Co _0.8 Fe _0.2 O _4-δ , so The electrode material described above has a dual-phase structure composed of a cubic structure and a honeycomb-like hexagonal structure; The preparation method of the solid oxide air electrode material includes the following steps: according to the stoichiometric ratio, first mix an appropriate amount of deionized water with Ba(NO ₃ ) ₂ , Sr(NO ₃ ) ₂ , Co(NO ₃ ) ₂ ·6H Mix ₂ O, Fe(NO ₃ ) ₃ 9H ₂ O, heat, stir and dissolve; after all dissolve, add ethylenediaminetetraacetic acid and citric acid monohydrate, then add ammonia water dropwise until the pH of the solution is between 7 and 8 , under the condition of heating and stirring, the water is volatilized to obtain a gel-like substance; the gel-like substance is dried in an oven to obtain the electrode material precursor, and then the precursor is placed in a muffle furnace for roasting to obtain the required electrode. Material; The roasting parameters are 950-1050°C roasting for 3-7h; The total molar ratio of EDTA and citric acid monohydrate to Ba, Sr, Co, Fe is 1.5-2.5:0.5-1.5:0.5-1.5. 2. The use according to claim 1, characterized in that the condition of the drying process is to treat at 200-300° C. for 5-8 hours.

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