A fuel cell cathode material with improved chromium resistance, preparation method and application

Abstract

The present invention specifically relates to a fuel cell cathode material for improving chromium resistance, a preparation method and an application, belonging to the field of solid oxide fuel cells. Large SOFC stacks usually use chromium-containing alloys as metal interconnect materials, which are somewhat toxic to the cathode. The present invention uses elemental fluorine to partially replace the O-site of the 0.9 Ta 0.1 O 3‑δ material to make SrCo 0.9 Ta 0.1 O 3‑δ F x (SCTFx, x = 0.05 - 0.2) material to improve the chromium resistance of the cathode of intermediate temperature solid oxide cells. In addition, the preparation process of the above cathode material is simple, with excellent performance and good industrialization prospects.

Description

Technical Field

[0001] The present invention belongs to the technical field of solid oxide fuel cells, and particularly relates to a fuel cell cathode material with improved chromium resistance, a preparation method thereof, and an application of the cathode material in the field of solid oxide fuel cells. Background Art

[0002] Disclosing the information of this background art section is only intended to enhance the overall understanding of the present invention, and it is not necessarily regarded as an admission or an indication in any form that this information constitutes the prior art already known to those of ordinary skill in the art.

[0003] A solid oxide fuel cell (SOFC) is an all-solid-state energy conversion device that directly converts the chemical energy in fuel into electrical energy, and has advantages such as high energy conversion efficiency, safety, and environmental friendliness. However, since large SOFC stacks usually use chromium-containing alloys as metal interconnect materials, at high temperatures, chromium oxide will form on their surfaces, and then react with air or water vapor to form chromium vapor, causing chromium poisoning of the cathode material and resulting in the performance degradation of the SOFC. Therefore, developing cathode materials with high chromium resistance is of great significance for the engineering application of SOFCs.

[0004] Currently, the mainstream cathode materials for SOFCs are mainly perovskite-type mixed ionic-electronic conductor (MIEC) oxides, such as single perovskite, double perovskite, and Ruddlesden-Popper structure perovskite materials. As a typical single perovskite-type MIEC oxide, SrCo 0.9 Ta 0.1 O 3-δ materials have excellent catalytic activity in the intermediate temperature range, so they are widely used as cathode materials. However, under long-term working conditions, the alkaline earth element Sr tends to segregate and accumulate on the cathode surface and react with the chromium vapor on the surface of the interconnect material to form an inert phase, which is not conducive to the performance of the SOFC stack.

[0005] The present invention believes that it is of great significance to develop SOFC cathode materials with excellent chromium resistance under long-term working conditions. Summary of the Invention

[0006] In order to overcome the deficiencies in the prior art and improve the tolerance of the cathode material to chromium elements, the present invention associates with doping part of fluorine elements into perovskite-type oxides to achieve the tolerance to the chromium environment. Verified by the present invention, the introduction of fluorine elements reduces the formation of secondary phases on the surface of perovskite materials and effectively improves the stability of the cathode material. In addition, the introduction of fluorine elements also effectively reduces the increase in polarization resistance of the half-cell in a chromium-containing atmosphere and improves the chromium resistance of the cathode material.

[0007] Based on the above achievements, the present invention provides the following technical solutions:

[0008] In the first aspect of the present invention, a fuel cell cathode material with improved chromium resistance is provided. The composition of the cathode material is shown by the following formula: SrCo 0.9 Ta 0.1 O 3-δ F x (x = 0.05~0.2) (abbreviated as SCTF), where δ is the value to ensure the electrical neutrality of the material; its XRD diffraction pattern includes 2 θ X-ray diffraction peaks at 33.00±0.1, 40.64±0.1, 47.20±0.1, 58.60±0.1, 68.70±0.1, and 78.12±0.1.

[0009] In the second aspect of the present invention, a preparation method of the cathode material described in the first aspect is provided, including the following steps: Weigh strontium carbonate (SrCO3), cobalt tetroxide (Co3O4), tantalum pentoxide (Ta2O5), and strontium fluoride (SrF2) according to the stoichiometric ratios of the corresponding chemical elements in SrCo 0.9 Ta 0.1 O 3-δ F x (x = 0.05~0.2) respectively, and perform ball milling using the wet milling method, then dry, press into tablets, and calcine to obtain the product.

[0010] The preparation method in the second aspect also has the following preferred implementation manners:

[0011] Preferably, an organic reagent is used as the solvent in the above ball milling process. Examples of the organic reagent include ethanol; the rotation speed of the ball milling is 220~260 r / min, and the time is 10~14h.

[0012] The above drying process can adopt thermal radiation drying, the drying temperature does not exceed 180°C, and the further preferred drying temperature is 140~160°C, and the drying time is 0.8~1.5h.

[0013] The above tablet pressing is realized by a tablet press. The dried powder is left standing for 100~150s under a pressure of 280~320 Mpa to obtain a dense tablet, and the dense tablet is calcined at 1000~1200°C for 8~12h to obtain SrCo 0.9 Ta 0.1 O 3-δ F x material.

[0014] In the third aspect of the present invention, a half-cell is provided. The half-cell includes the cathode material described in the first aspect and also includes a solid electrolyte. The solid electrolyte is selected from La0.9 Sr 0.1 Ga 0.8 Mg 0.2 O3 (LSGM), Sm 0.2 Ce 0.8 O 1.9 (SDC), Ce 0.9 Gd 0.1 O 1.95 (GDC), or a combination of one or more of them.

[0015] In the fourth aspect of the present invention, a method for preparing the half-cell described in the third aspect is provided, including the following steps: The cathode material described in the first aspect is ball-milled by wet milling to obtain a powder, the powder is mixed with an organic binder and made into a cathode slurry, and the slurry is uniformly coated on the surface of the solid electrolyte, and then calcined after drying to obtain the product.

[0016] In the preparation method of the fourth aspect, it is preferred to disperse the cathode material with an organic reagent during the ball-milling process, such as ethanol. The ball-milling speed is 220 - 260 r / min, and the time is 22 - 26 h; Since the cathode material prepared by the method described in the second aspect is a dense sheet, before adding it to the ball-milling, the dense sheet can be pretreated into a powder by grinding or other means to make it better dissolve in the above-mentioned organic solvent.

[0017] The above-mentioned organic binder is an ethyl cellulose terpineol binder, where the mass ratio of ethyl cellulose to terpineol is 1:12 - 19, and further ratios can be adjusted conventionally by those skilled in the art according to usage requirements; while the mass ratio of the cathode material powder to the organic binder is 1:1 - 2.

[0018] The above-mentioned coating can be achieved by a screen printing machine. After drying, it is calcined at 800 - 1200 °C for 1 - 3 h to obtain the half-cell with the above-mentioned cathode material.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The cathode material (SCTF) prepared by the present invention belongs to a new cathode material, which has the characteristics of simple composition and simple synthesis process. Moreover, due to the fact that F- with a higher electronegativity occupies the oxygen vacancies, the valence states of metal ions in the perovskite increase, and its acidity improves, which can effectively enhance the chromium resistance of the material.

[0021] 2. Verified by the present invention, the battery with the SCTF cathode shows excellent chromium resistance compared with the battery with the SCT cathode and can work stably in a chromium-containing atmosphere. Description of the Drawings

[0022] The accompanying drawings of the specification, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention.

[0023] Figure 1 XRD diagrams of the cathode materials in Examples 1 - 3 and the comparative example;

[0024] Among them, Figure 1 In (a) are the XRD diagrams of the cathode materials in Examples 1 - 3 and the comparative example;

[0025] Figure 1 In (b) is Figure 1 2 of (a) in θ is an enlarged view of the main peak at 33.00 ± 0.1;

[0026] Figure 2 SEM diagrams of the dense samples in Examples 1 - 3 and the comparative example after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0027] Among them, Figure 2 In (a) is the SEM diagram of the dense sample in the comparative example after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0028] Figure 2 In (b) is the SEM diagram of the dense sample in Example 1 after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0029] Figure 2 In (c) is the SEM diagram of the dense sample in Example 2 after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0030] Figure 2 In (d) is the SEM diagram of the dense sample in Example 3 after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0031] Figure 3 XRD diagrams of the dense samples in Examples 1 - 3 and the comparative example after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0032] Among them, Figure 3 In (a) are the XRD diagrams of the dense samples in Examples 1 - 3 and the comparative example after being treated in a chromium-containing atmosphere at 700°C for 24 h;

[0033] Figure 3 In (b) is Figure 3 2 of (a) in θ is an enlarged view of segments 24 - 30;

[0034] Figure 4It is the AC impedance spectrogram of the half-cells based on the cathode materials of Examples 1 - 3 and Comparative Example varying with time under a chromium-containing atmosphere at 700°C for 22 h;

[0035] Among them, Figure 4 in (a) is the AC impedance spectrogram of the half-cell in the Comparative Example varying with time under a chromium-containing atmosphere at 700°C for 22 h;

[0036] Figure 4 in (b) is the AC impedance spectrogram of the half-cell in Example 1 varying with time under a chromium-containing atmosphere at 700°C for 22 h;

[0037] Figure 4 in (c) is the AC impedance spectrogram of the half-cell in Example 2 varying with time under a chromium-containing atmosphere at 700°C for 22 h;

[0038] Figure 4 in (d) is the AC impedance spectrogram of the half-cell in Example 3 varying with time under a chromium-containing atmosphere at 700°C for 22 h. Detailed implementation manners

[0039] It should be noted that the following detailed descriptions are all illustrative and are intended to provide further explanations of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0040] It should be noted that the terms used herein are only for describing the specific implementation manners and are not intended to limit the exemplary implementation manners according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of the features, steps, operations, devices, components, and / or combinations thereof.

[0041] Term explanations:

[0042] SCTF: That is, the fuel cell cathode material for improving chromium resistance described in the first aspect of the present invention, and the composition of the material is shown by the following formula: SrCo 0.9 Ta 0.1 O 3-δ F x (x = 0.05 - 0.2), abbreviated as SCTF.

[0043] SCT: The single perovskite-type MIEC oxide without fluorine element provided in the Comparative Example of the present invention, and the chemical formula is SrCo 0.9 Ta 0.1 O 3-δ , abbreviated as SCT.

[0044] In order to enable those skilled in the art to more clearly understand the technical solution of the present invention, the technical solution of the present invention will be described in detail below in combination with specific embodiments and comparative examples.

[0045] Example 1

[0046] In this example, a fuel cell cathode material with improved chromium resistance and a corresponding half-cell are provided. The structural formula of the cathode material is SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and the preparation method includes the following steps:

[0047] (1) Weigh SrCO3, Co3O4, Ta2O5, and SrF2 respectively according to the stoichiometric ratio of the corresponding chemical elements in the chemical formula SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and then dissolve each raw material into a ball-milling tank containing ethanol in turn;

[0048] (2) Place the ball-milling tank obtained in step (1) in a ball mill and ball-mill for 12 h at a rotation speed of 240 r / min;

[0049] (3) Place the ball-milled solution in an oven and treat it at 150 °C for 1 h to obtain a mixed powder;

[0050] (4) Use a tablet press to let the mixed powder obtained in step (3) stand for 120 s under a pressure of 300 MPa to obtain a dense tablet, and calcine it at 1100 °C for 10 h to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 material.

[0051] In this example, a half-cell based on SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode is also provided, and its preparation method is as follows:

[0052] S1. Use Sm 0.2 Ce 0.8 O 1.9 (SDC) powder as the electrolyte, and obtain the electrolyte through a tablet pressing and calcination process;

[0053] S2. Manually grind the SrCo 0.9 Ta 0.1 O 3-δ F 0.05 dense tablet for 30 min to obtain SrCo0.9 Ta 0.1 O 3-δ F 0.05 powder and dissolve it in a ball milling jar containing ethanol. Place it in a ball mill and ball mill for 24 h at a rotational speed of 240 r / min to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder;

[0054] S3. Grind and mix the SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder obtained in S2 and ethyl cellulose - terpineol (mass fraction of ethyl cellulose is 7%) evenly by grinding according to a mass ratio of 1:1.5 to prepare a cathode slurry;

[0055] S4. Uniformly coat the cathode slurry obtained in S3 on the surface of the electrolyte prepared in step S1 with a screen printing machine. After drying, calcine it at 1000 °C for 2 h to obtain a half - cell with SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode.

[0056] Example 2

[0057] In this example, another fuel cell cathode material for improving chromium resistance and the corresponding half - cell are provided. The difference from Example 1 is that the structural formula of the cathode material is SrCo 0.9 Ta 0.1 O 3-δ F 0.10 , and SrCO3, Co3O4, Ta2O5, SrF2 are weighed respectively according to the stoichiometric ratio of the corresponding chemical elements in the chemical formula SrCo 0.9 Ta 0.1 O 3-δ F 0.10 . Then, each raw material is dissolved into a ball milling jar containing ethanol in turn. Other steps and the corresponding half - cell preparation steps are the same as those in Example 1.

[0058] Example 3

[0059] In this example, another fuel cell cathode material for improving chromium resistance and the corresponding half - cell are provided. The difference from Example 1 is that the structural formula of the cathode material is SrCo 0.9 Ta 0.1 O 3-δ F 0.20 , and according to the chemical formula SrCo 0.9 Ta 0.1 O3-δ F 0.20 The stoichiometric ratios of the corresponding chemical elements in 0.20 are used to weigh SrCO3, Co3O4, Ta2O5, and SrF2 respectively. Then, each raw material is successively dissolved into a ball-milling tank containing ethanol. Other steps and the corresponding preparation steps of the half-cell are the same as those in Example 1.

[0060] Example 4

[0061] In this example, another fuel cell cathode material with improved chromium resistance is provided, and its structural formula is SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and the preparation method includes the following steps:

[0062] (1) Weigh SrCO3, Co3O4, Ta2O5, and SrF2 respectively according to the stoichiometric ratios of the corresponding chemical elements in the chemical formula SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and then successively dissolve each raw material into a ball-milling tank containing ethanol;

[0063] (2) Place the ball-milling tank obtained in step (1) in a ball mill and ball-mill for 14 h at a rotation speed of 220 r / min;

[0064] (3) Place the ball-milled solution in an oven and treat it at 140 °C for 1.5 h to obtain a mixed powder;

[0065] (4) Use a tablet press to let the mixed powder in step (3) stand for 100 s under a pressure of 320 MPa to obtain a dense tablet, and calcine it at 1000 °C for 12 h to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 material.

[0066] In this example, a half-cell based on SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode is also provided, and its preparation method is as follows:

[0067] S1. Use Sm 0.2 Ce 0.8 O 1.9 (SDC) powder as the electrolyte, and obtain the electrolyte through tablet pressing and calcination processes;

[0068] S2. Place SrCo 0.9 Ta 0.1 O 3-δ F 0.05The dense tablets were manually ground for 30 min to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 powder, which was dissolved in a ball milling jar containing ethanol and placed in a ball mill to be ball milled at a rotation speed of 220 r / min for 26 h to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder;

[0069] S3. The SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder obtained in S2 was thoroughly ground and mixed evenly with ethyl cellulose - terpineol (the mass fraction of ethyl cellulose was 6.5%) in a ratio of 1:1 to prepare a cathode slurry;

[0070] S4. The cathode slurry obtained in S3 was evenly coated on the surface of the electrolyte prepared in step S1 by a screen printing machine, dried and calcined at 800 °C for 3 h to obtain a half - cell with a SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode.

[0071] Example 5

[0072] In this example, another fuel cell cathode material with improved chromium resistance was provided, and its structural formula was SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and the preparation method included the following steps:

[0073] (1) SrCO3, Co3O4, Ta2O5, and SrF2 were weighed respectively according to the stoichiometric ratio of the corresponding chemical elements in the chemical formula SrCo 0.9 Ta 0.1 O 3-δ F 0.05 , and then each raw material was successively dissolved in a ball milling jar containing ethanol;

[0074] (2) The ball milling jar obtained in step (1) was placed in a ball mill and ball milled at a rotation speed of 260 r / min for 10 h;

[0075] (3) The ball - milled solution was placed in an oven and treated at 160 °C for 0.8 h to obtain a mixed powder;

[0076] (4) Use a tablet press to let the mixed powder in step (3) stand for 150 s under a pressure of 280 MPa to obtain a dense tablet, and calcine it at 1200 °C for 8 h to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 material.

[0077] In this embodiment, a half-cell based on SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode is also provided, and its preparation method is as follows:

[0078] S1. Use Sm 0.2 Ce 0.8 O 1.9 (SDC) powder as the electrolyte, and obtain the electrolyte through tablet pressing and calcination processes;

[0079] S2. Manually grind the SrCo 0.9 Ta 0.1 O 3-δ F 0.05 dense tablet for 30 min to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 powder, and dissolve it in a ball milling jar containing ethanol, and place it in a ball mill to ball mill for 22 h at a rotation speed of 240 r / min to obtain SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder;

[0080] S3. Mix the SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode powder obtained in S2 and ethyl cellulose-terpineol (the mass fraction of ethyl cellulose is 6.5%) in a ratio of 1:2, and grind and mix them evenly to prepare a cathode slurry;

[0081] S4. Uniformly coat the cathode slurry obtained in S3 on the surface of the electrolyte prepared in step S1 with a screen printing machine, dry it, and calcine it at 1200 °C for 1 h to obtain a half-cell with SrCo 0.9 Ta 0.1 O 3-δ F 0.05 cathode.

[0082] The SrCo 0.9 Ta 0.1 O 3-δ Fx The material has electrochemical properties that are basically close to those of Examples 1 - 3. When x is adjusted within the range of x = 0.05 - 0.2, the parameters in its preparation method can be adjusted accordingly with reference to Examples 4 and 5.

[0083] Comparative Example

[0084] In this comparative example, a single - perovskite - type MIEC oxide without fluorine element is provided. The preparation method includes the following steps:

[0085] (1) Weigh SrCO3, Co3O4, and Ta2O5 respectively according to the stoichiometric ratios of the corresponding chemical elements in the chemical formula SrCo 0.9 Ta 0.1 O 3-δ Then dissolve each raw material successively into a ball - milling tank containing ethanol.

[0086] (2) Place the ball - milling tank obtained in step (1) in a ball mill and ball - mill for 12 h at a rotation speed of 240 r / min.

[0087] (3) Place the ball - milled solution in an oven and treat it at 150 °C for 1 h to obtain a mixed powder.

[0088] (4) Use a tablet press to let the mixed powder in step (3) stand for 120 s under a pressure of 300 MPa to obtain a dense tablet, and then calcine it at 1100 °C for 10 h to obtain the SrCo 0.9 Ta 0.1 O 3-δ material (abbreviated as SCT material).

[0089] In this comparative example, a half - cell based on SrCo 0.9 Ta 0.1 O 3-δ cathode is also provided. The preparation method includes the following steps:

[0090] S1. Use Sm 0.2 Ce 0.8 O 1.9 (SDC) powder as the electrolyte, and obtain the electrolyte through tablet - pressing and calcination processes.

[0091] S2. Manually grind the SrCo 0.9 Ta 0.1 O 3-δ dense tablet for 30 min to obtain SrCo 0.9 Ta 0.1 O 3-δ powder, and dissolve it in a ball - milling tank containing ethanol, then place it in a ball mill and ball - mill for 24 h at a rotation speed of 240 r / min to obtain SrCo 0.9 Ta0.1 O 3-δ Cathode powder;

[0092] S3. Mix the SrCo obtained in S2 0.9 Ta 0.1 O 3-δ The cathode powder and ethyl cellulose - terpineol are ground and mixed evenly according to a mass ratio of 1:1.5 to prepare a cathode slurry;

[0093] S4. The cathode slurry obtained in S3 is evenly coated on the surface of the electrolyte prepared in step S1 by a screen printing machine, dried and then calcined at 1000 °C for 2 h to obtain a half - cell with SrCo 0.9 Ta 0.1 O 3-δ cathode.

[0094] Performance test

[0095] Figure 1 XRD patterns of the cathode materials in Examples 1 - 3 and the comparative example. All the synthesized materials obtained pure phases. Figure 1 In (b) is Figure 1 An enlarged view of the 33 - degree main peak in (a). It can be seen that as the doping amount of fluorine element (F) increases, the diffraction peak gradually moves towards a higher angle, proving that the lattice constant gradually decreases with the increase of the doping amount, indicating that F is successfully incorporated into the material lattice. And the main peak of the example changes from the double peak of the comparative example to a single peak, indicating that the lattice symmetry of the example is improved, which is beneficial to its catalytic activity.

[0096] Figure 2 SEM images of the cathode materials in Examples 1 - 3 and the comparative example after being treated in a chromium - containing atmosphere at 700 °C for 24 h. It can be seen that after the comparative - example SCT material is treated in a chromium - containing atmosphere, there are many secondary - phase particles on the surface. While after Examples 1 - 3 doped with F are treated under the same conditions, the secondary phases on the surface are significantly reduced, indicating that the incorporation of F can significantly improve the stability of the material in a chromium - containing atmosphere.

[0097] Figure 3 XRD patterns of the cathode materials in Examples 1 - 3 and the comparative example after being treated in a chromium - containing atmosphere at 700 °C for 24 h. It can be seen that after treatment, diffraction peaks attributed to the SrCrO4 secondary phase appear on the surface of the comparative - example SCT, indicating that the secondary phase generated on its surface is SrCrO4. While no such secondary - phase diffraction peaks are observed for Examples 1 - 3 after treatment, further confirming that the amount of secondary - phase generation on their surfaces is lower.

[0098] Figure 4The AC impedance spectrogram as a function of time for the half-cells based on the cathode materials of Examples 1 - 3 and the comparative example was tested in a chromium-containing atmosphere at 700 °C for 22 h. It can be seen that after 22 h of testing, the polarization resistance of the half-cell based on the cathode material of Comparative Example SCT increased from an initial 0.120 Ω cm 2 to 1.150 Ω cm 2 , indicating a significant decrease in the activity of the SCT cathode material. After testing for 22 h under the same conditions, the cells based on the cathode materials of Examples 1 - 3 all showed less growth in polarization resistance, increasing to 0.416 Ω cm 2 , 0.272 Ω cm 2 and 0.495 Ω cm 2 , respectively, confirming that F substitution for O can effectively improve the chromium resistance of the SCT cathode.

[0099] Table 1 Polarization resistance values of the half-cells in Examples 1 - 3 and the comparative example

[0100]

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A fuel cell cathode material with improved chromium resistance, characterized in that, The composition of the cathode material is shown by the following formula: SrCo 0.9 Ta 0.1 O 3-δ F x , where x = 0.05 to 0.2; its XRD diffraction pattern contains 2 θ X-ray diffraction peaks at 33.00 ± 0.1, 40.64 ± 0.1, 47.20 ± 0.1, 58.60 ± 0.1, 68.70 ± 0.1, and 78.12 ± 0.1; The preparation method of the cathode material comprises the following steps: Weigh SrCO3, Co3O4, Ta2O5, and SrF2 according to the stoichiometric ratio of the corresponding chemical elements in SrCo 0.9 Ta 0.1 O 3-δ F x , and perform ball milling by the wet milling method, then dry. Let the dried powder stand for 100 - 150 s under a pressure of 280 - 320 Mpa to obtain a dense sheet; calcine the dense sheet at 1000 - 1200 °C for 8 - 12 h to obtain SrCo 0.9 Ta 0.1 O 3-δ F x Material tablets are pressed and calcined to obtain the product.

2. The cathode material according to claim 1, wherein In the ball milling process, ethanol is used as a solvent, the rotation speed of the ball milling is 220 - 260 r / min, and the time is 10 - 14 h.

3. The cathode material according to claim 1, characterized in that, The drying temperature is 140 - 160 °C, and the drying time is 0.8 - 1.5 h.

4. A half-cell, characterized in that, The half-cell includes the cathode material described in claim 1, and also includes a solid electrolyte, and the solid electrolyte is selected from one or a combination of several of LSGM, SDC, and GDC.

5. The preparation method of the half-cell according to claim 4, characterized in that, It includes the following steps: the cathode material is ball milled by a wet milling method to obtain a powder, the powder is mixed with an organic binder to form a cathode slurry, and the cathode slurry is uniformly coated on the surface of the solid electrolyte and calcined after drying to obtain the product.

6. The preparation method of the half-cell according to claim 5, wherein, In the ball milling, ethanol is used as a solvent, the rotation speed of the ball milling is 220 - 260 r / min, and the time is 22 - 26 h.

7. The preparation method of the half-cell according to claim 5, characterized in that, The organic binder is an ethyl cellulose terpineol binder, where the mass ratio of ethyl cellulose to terpineol is 1∶12 - 19, and the mass ratio of the cathode material powder to the organic binder is 1:1 - 2.

8. The method for preparing the half-cell according to claim 5, characterized in that, The coating is realized by a screen printing machine, and after the cathode slurry is dried, it is calcined at 800 - 1200 °C for 1 - 3 h to obtain the product.

Images