Preparation method of solid oxide fuel cell connector coating

Abstract

The invention relates to a preparation method of a solid oxide fuel cell connector coating, and belongs to the technical field of fuel cells. The method includes: obtaining a connector; mixing the raw materials of the coating to obtain a mixture; the mixture and the organic slurry are mixed, and silk screen slurry is obtained; printing the silk screen slurry to a connector, and then drying to convert the silk screen slurry into a precursor material to obtain a first intermediate attached with the precursor material; carrying out dry pressing treatment on the precursor material of the first intermediate to reduce internal gaps of the precursor material so as to obtain a second intermediate; and sintering the second intermediate so as to convert the precursor material into a coating, thereby completing the preparation. A mixture of coating raw materials is attached to a connecting piece in a silk-screen printing mode, the components and the attaching thickness of the raw materials are easy to control, then the components and the thickness of a final coating are controlled, then gaps of precursor materials are effectively reduced in a dry pressing treatment mode, and then the density of the final coating is increased.

Description

Technical Field

[0001] This application relates to the technical field of fuel cells, and particularly to a method for preparing a coating for a solid oxide fuel cell interconnect. Background Art

[0002] A solid oxide fuel cell is an all-solid-state chemical power generation device that directly converts the chemical energy of reactants into electrical energy at medium and high temperatures. It is a green energy source with little environmental pollution. However, its high operating cost hinders its popularization and use. Among them, the interconnect is a key component of the solid oxide fuel cell and accounts for 30% - 70% of the total cost. Therefore, as long as the cost of the interconnect is significantly reduced, the cost of the solid oxide fuel cell can be greatly reduced. Recently, with the operating temperature of the solid oxide fuel cell decreasing from 1000°C to 600°C - 800°C, it has become possible to replace traditional ceramic materials with inexpensive ferritic stainless steel materials to prepare the interconnect. However, the oxidation products generated by the oxidation of ferritic stainless steel at higher temperatures can increase the contact resistance, and the volatilization of Cr in the stainless steel will cause "cathode poisoning", resulting in the performance degradation of the battery pack. Currently, the main method to solve this problem is to apply a conductive protective coating on the surface of the stainless steel interconnect. Among them, the copper-manganese spinel coating with good thermal stability, high conductivity, and moderate thermal expansion coefficient has become one of the most effective protective coatings on the surface of the stainless steel interconnect and has attracted much attention.

[0003] Currently, the main preparation methods of the copper-manganese spinel coating are: electrodeposition, slurry coating, screen printing, plasma spraying, physical vapor deposition, etc. Among them, the electrodeposition method is to deposit a copper-manganese alloy coating on the stainless steel surface by electroplating process, and then the alloy coating is transformed into copper-manganese spinel by high-temperature oxidation. This method has the advantages of low cost, adjustable coating thickness, and adaptability to complex substrate shapes. However, in the copper-manganese alloy electroplating system, the standard potential of Cu 2+ / Cu is 0.337VH, and the standard potential of Mn 2+ / Mn is -1.18VH. The difference between the two standard potentials is very large, and manganese is the metal with the most negative standard potential among the electroplatable metals in aqueous solution. Therefore, it is very difficult to electroplate copper-manganese alloy. G. Zangari et al. found that Cu-Mn alloy can be electroplated on the stainless steel surface in a simple sulfate system with a pH of 2.6 - 2.8 and 6.4 - 6.8. When the current density is low (<100mA·cm -2 ), the coating is spongy; when the current density is between 150mA·cm -2 and 400mA·cm -2 , the coating is crystalline; when the current density is large (>400mA·cm -2 ), the coating tends to be amorphous. Among them, the better-quality coating contains 2at.% - 14at.% of Cu. In copper-manganese spinel, Mn 1.5Cu 1.5 The thermal expansion coefficient and electrical conductivity of CuO4 meet the requirements of the connector coating. Therefore, the molar content of copper in the copper-manganese spinel coating cannot be lower than 30%. Otherwise, it is difficult to obtain a copper-manganese spinel coating that meets the performance requirements. To solve this problem, Chinese Patent Application CN201610643626.3, a copper-manganese alloy plating solution for preparing a copper-manganese spinel coating and its application, discloses a copper-manganese alloy plating solution for preparing a copper-manganese spinel coating, which includes the following components at the following concentrations: copper ion source 0.025 mol / L to 0.1 mol / L; manganese ion source 0.25 mol / L to 0.5 mol / L; the manganese ion source is manganese chloride; chelating agent 0.03 mol / L to 0.1 mol / L; buffer 20 g / L to 200 g / L; stabilizer 10 g / L to 50 g / L; the stabilizer is ammonium bromide; the balance is solvent; and discloses a method for preparing a copper-manganese spinel coating using the copper-manganese alloy plating solution, including the following steps: Step 1, pretreatment before plating, including degreasing treatment and activation treatment. The specific process is as follows: Step 101, degreasing treatment: Heat the alkaline degreasing agent to 80 °C, then immerse the metal part to be plated in the heated alkaline degreasing agent for 30 min, take it out, clean it and dry it; the alkaline degreasing agent includes the following components at the following concentrations: trisodium phosphate 30 g / L to 40 g / L, sodium carbonate 40 g / L to 50 g / L, sodium hydroxide 50 g / L to 60 g / L, sodium silicate 5 g / L to 6 g / L, and the balance is deionized water; Step 102, activation treatment: Immerse the metal part to be plated after degreasing treatment in step 101 in a hydrochloric acid-nitric acid mixed acid solution for 60 s, then immerse it in dilute sulfuric acid with a mass percentage concentration of 10% to 20% for 60 s, take it out and clean it; the mass percentage concentration of HCl in the hydrochloric acid-nitric acid mixed acid solution is 20% to 30%, and the mass percentage concentration of HNO3 is 5% to 10%; Step 2, electroplating treatment: Place the metal part to be plated after activation treatment in step 102 in a plating bath filled with the copper-manganese alloy plating solution, use the metal part to be plated after activation treatment as the cathode, and use a graphite plate as the anode. At a plating solution temperature of 20 °C to 25 °C and a current density of 200 mA·cm -2 ~700 mA·cm -2Electroplating is carried out for 10 min to 30 min under the following conditions, and then the electroplated metal parts are taken out, cleaned with deionized water and dried, and a copper-manganese alloy coating is obtained on the surface of the metal parts; Step 3. Post-treatment: Place the copper-manganese alloy coating described in Step 2 in a tubular furnace, first perform dehydrogenation treatment for 2 h under the protection of an argon atmosphere at a temperature of 800 °C, and then oxidize the copper-manganese alloy coating after dehydrogenation treatment for 2 h under an atmospheric atmosphere at a temperature of 800 °C, and finally obtain a copper-manganese spinel coating on the surface of the metal parts. This method can narrow the deposition potential of the copper-manganese alloy by adding a suitable complexing agent, making the manganese content in the copper-manganese alloy coating moderate and the coating quality good. However, the electro-deposition method still has the problem of being unable to control the composition of the coating, and cracks are likely to appear during the sintering process, making it impossible to achieve complete densification. In addition, the electrolysis after its preparation requires additional treatment to reduce the impact on the environment. Among other preparation methods, the efficiency of magnetron sputtering is low, resulting in high costs. And the cost of atmospheric plasma spraying equipment is high, and the thickness of the coating prepared by it does not meet the requirements. Summary of the Invention

[0004] The present application provides a method for preparing a coating for a solid oxide fuel cell connector to form a dense, precisely composition-controlled, and thickness-meeting coating.

[0005] In a first aspect, the present application provides a method for preparing a coating for a solid oxide fuel cell connector, the method comprising:

[0006] Obtain a connector;

[0007] Mix the raw materials of the coating to be prepared to obtain a mixed material;

[0008] Mix the mixed material and an organic slurry to obtain a screen printing slurry;

[0009] Print the screen printing slurry onto the connector, and then dry it to convert the screen printing slurry into a precursor material, obtaining a first intermediate attached with the precursor material;

[0010] Perform dry pressing on the precursor material of the first intermediate to reduce the internal voids of the precursor material, obtaining a second intermediate;

[0011] Sinter the second intermediate to convert the precursor material into a coating, completing the preparation.

[0012] As an optional implementation manner, the method further includes: pre-treating the connector.

[0013] As an optional implementation manner, the pre-treatment includes polishing.

[0014] As an optional implementation manner, the mesh number of the polishing is 400 to 600 mesh.

[0015] As an alternative embodiment, the mesh number of the polishing is 450 - 550 meshes.

[0016] As an alternative embodiment, the mesh number of the polishing is 480 - 520 meshes.

[0017] As an alternative embodiment, the raw materials of the coating include Cu and Mn.

[0018] As an alternative embodiment, the molar ratio of Cu and Mn is 1:2 - 2:1.

[0019] As an alternative embodiment, the molar ratio of Cu and Mn is 1.5:2 - 3.5:2.

[0020] As an alternative embodiment, the molar ratio of Cu and Mn is 2:2 - 3:2.

[0021] As an alternative embodiment, the molar ratio of Cu and Mn is 1:2 - 1:1.

[0022] As an alternative embodiment, the organic slurry includes terpineol.

[0023] As an alternative embodiment, the mixing relationship between the mixture and the organic slurry satisfies: for example, 0.5 - 1.5 g of the mixture is dissolved in each milliliter of the organic slurry.

[0024] As an alternative embodiment, the drying temperature is 80 - 100 °C; and / or

[0025] The drying time is 10 - 30 minutes.

[0026] As an alternative embodiment, the drying temperature is 85 - 95 °C; and / or

[0027] The drying time is 15 - 25 minutes.

[0028] As an alternative embodiment, the pressure of the dry pressing treatment is 100 - 200 Mpa.

[0029] As an alternative embodiment, the pressure of the dry pressing treatment is 130 - 170 Mpa.

[0030] As an alternative embodiment, the sintering temperature is 800 - 900 °C; and / or

[0031] The sintering time is 0.5 - 2 hours.

[0032] As an alternative embodiment, the sintering temperature is 830 - 870 °C; and / or

[0033] The sintering time is 1 to 1.5 hours.

[0034] As an alternative embodiment, the connector includes a stainless steel connector.

[0035] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0036] The method provided by the embodiment of the present application attaches the mixture of coating raw materials to the connector by screen printing, which is easy to control the composition of the raw materials and the thickness of the attachment, thereby controlling the composition and thickness of the final coating. Then, through dry pressing treatment, the gaps of the precursor material are effectively reduced, thereby increasing the density of the final coating. Finally, the coating is prepared by sintering, achieving the purpose of forming a dense coating with precisely controlled composition and reaching the required thickness. Description of the Drawings

[0037] The drawings herein are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present application and used together with the specification to explain the principles of the present application.

[0038] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, for those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0039] Figure 1 is a schematic flow chart of the method provided by the embodiment of the present application;

[0040] Figure 2 is a schematic diagram of the preparation process provided by the embodiment of the present application;

[0041] Figure 3 is the XRD pattern after the reaction sintering of the precursor material Mn + Cu provided by Embodiment 1 of the present application;

[0042] Figure 4 is a cross-sectional view of the coating provided by Embodiment 1 of the present application;

[0043] Figure 5 is a cross-sectional view of the coating provided by Embodiment 2 of the present application. Detailed Embodiments

[0044] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope protected by this application.

[0045] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments, equipment, etc. used in this application can be obtained through market purchases or can be prepared by existing methods.

[0046] A solid oxide fuel cell is a fully solid-state chemical power generation device that directly converts the chemical energy of reactants into electrical energy at medium and high temperatures. It is a green energy source with little environmental pollution. However, its high operating cost hinders its popularization and use. Among them, the interconnect is a key component of the solid oxide fuel cell and accounts for 30% - 70% of the total cost. Therefore, as long as the cost of the interconnect is significantly reduced, the cost of the solid oxide fuel cell can be greatly reduced. Recently, as the operating temperature of the solid oxide fuel cell has been reduced from 1000°C to 600°C - 800°C, it has become possible to replace traditional ceramic materials with inexpensive ferritic stainless steel materials to prepare the interconnect. However, the oxidation products generated by the oxidation of ferritic stainless steel at higher temperatures can increase the contact resistance, and the volatilization of Cr in the stainless steel will cause "cathode poisoning", resulting in the performance degradation of the battery pack. Currently, the main method to solve this problem is to apply a conductive protective coating on the surface of the stainless steel interconnect. Among them, the copper-manganese spinel coating with good thermal stability, high electrical conductivity, and moderate thermal expansion coefficient has become one of the most effective protective coatings on the surface of the stainless steel interconnect and has attracted much attention.

[0047] Currently, the main preparation methods of the copper-manganese spinel coating are: electrodeposition, slurry coating, screen printing, plasma spraying, physical vapor deposition, etc. Among them, the electrodeposition method is a method of depositing a copper-manganese alloy coating on the stainless steel surface by using an electroplating process, and then the alloy coating is transformed into copper-manganese spinel through high-temperature oxidation. This method has the advantages of low cost, adjustable coating thickness, and adaptability to complex substrate shapes. However, in the copper-manganese alloy electroplating system, the standard potential of Cu 2+ / Cu is 0.337VH, and the standard potential of Mn 2+ / Mn is -1.18VH. The difference in their standard potentials is very large, and manganese is the metal with the most negative standard potential among the electroplatable metals that can be obtained from aqueous solutions. Therefore, it is very difficult to electroplate copper-manganese alloys. G. Zangari et al. found that Cu-Mn alloys can be electroplated on the stainless steel surface in a simple sulfate system with a pH of 2.6 - 2.8 and 6.4 - 6.8. When the current density is low (<100mA·cm -2), the coating is spongy; when the current density is 150 mA·cm -2 ~400 mA·cm -2 , the coating is crystalline; when the current density is relatively large, > 400 mA·cm -2 , the coating tends to be amorphous. Among them, the coating with better quality contains 2 at.% to 14 at.% of Cu. In copper manganese spinel, the thermal expansion coefficient and conductivity of Mn 1.5 Cu 1.5 O4 meet the requirements of the interconnect coating. Therefore, the molar content of copper in the copper manganese spinel coating cannot be lower than 30%, otherwise it is difficult to obtain a copper manganese spinel coating that meets the performance requirements. To solve this problem, Chinese Patent Application for Invention CN201610643626.3, a copper manganese alloy plating solution for preparing a copper manganese spinel coating and its application, discloses a copper manganese alloy plating solution for preparing a copper manganese spinel coating, including the following components in the following concentrations: copper ion source 0.025 mol / L to 0.1 mol / L; manganese ion source 0.25 mol / L to 0.5 mol / L; the manganese ion source is manganese chloride; chelating agent 0.03 mol / L to 0.1 mol / L; buffer 20 g / L to 200 g / L; stabilizer 10 g / L to 50 g / L; the stabilizer is ammonium bromide; the balance is solvent; and discloses a method for preparing a copper manganese spinel coating using the copper manganese alloy plating solution, including the following steps: Step 1, pretreatment before plating, including degreasing treatment and activation treatment. The specific process is as follows: Step 101, degreasing treatment: Heat the alkaline degreasing agent to 80 °C, then immerse the metal part to be plated in the heated alkaline degreasing agent for 30 min, take it out, clean it and dry it; the alkaline degreasing agent includes the following components in the following concentrations: trisodium phosphate 30 g / L to 40 g / L, sodium carbonate 40 g / L to 50 g / L, sodium hydroxide 50 g / L to 60 g / L, sodium silicate 5 g / L to 6 g / L, and the balance is deionized water; Step 102, activation treatment: Immerse the metal part to be plated after degreasing treatment in step 101 in a hydrochloric acid-nitric acid mixed acid solution for 60 s, then immerse it in dilute sulfuric acid with a mass percentage concentration of 10% to 20% for 60 s, take it out and clean it; the mass percentage concentration of HCl in the hydrochloric acid-nitric acid mixed acid solution is 20% to 30%, and the mass percentage concentration of HNO3 is 5% to 10%; Step 2, electroplating treatment: Place the metal part to be plated after activation treatment in step 102 in a plating bath filled with the copper manganese alloy plating solution, use the metal part to be plated after activation treatment as the cathode, and use a graphite plate as the anode. At a plating solution temperature of 20 °C to 25 °C and a current density of 200 mA·cm -2 ~700 mA·cm -2Electroplating for 10min to 30min under the conditions of , then taking out the electroplated metal parts, cleaning them with deionized water and blowing them dry, and obtaining a copper-manganese alloy coating on the surface of the metal parts; Step 3, post-treatment: placing the copper-manganese alloy coating described in step 2 in a tubular furnace, first dehydrogenating for 2h under the protection of argon atmosphere at a temperature of 800°C, and then oxidizing the dehydrogenated copper-manganese alloy coating in an atmospheric atmosphere at a temperature of 800°C for 2h, and finally obtaining a copper-manganese spinel coating on the surface of the metal parts. This method closes the deposition potential of the copper-manganese alloy by adding a suitable complexing agent, so that the manganese content in the copper-manganese alloy coating is moderate and the coating quality is good. However, the electrodeposition method still has the problem of being unable to control the composition of the coating, and cracks are prone to occur during the sintering process, and it is impossible to achieve complete density. In addition, the electrolysis after its preparation requires additional treatment to reduce the impact on the environment. Among other preparation methods, the efficiency of magnetron sputtering is low, resulting in high costs. However, the atmospheric plasma spraying equipment is expensive, and the thickness of the coating prepared by it does not meet the requirements.

[0048] The inventor intends to provide a new preparation method to form a dense coating with precisely controlled composition and a desired thickness.

[0049] Figure 1 A schematic diagram of a method provided in an embodiment of the present application, Figure 2 A schematic diagram of the preparation process provided in the embodiments of the present application; Figure 1 and Figure 2 As shown, the embodiment of the present application provides a method for preparing a coating of a solid oxide fuel cell connector, the method comprising:

[0050] S1. Obtaining a linker;

[0051] In some embodiments, the method further includes: preprocessing the connector. Further, the preprocessing includes polishing. Wherein, the mesh number of the polishing is 400 - 600 mesh. Further, the mesh number of the polishing is 450 - 550 mesh. Still further, the mesh number of the polishing is 480 - 520 mesh. Exemplarily, the mesh number of the polishing can be 400 mesh, 410 mesh, 420 mesh, 430 mesh, 440 mesh, 450 mesh, 460 mesh, 470 mesh, 480 mesh, 490 mesh, 500 mesh, 510 mesh, 520 mesh, 530 mesh, 540 mesh, 550 mesh, 560 mesh, 570 mesh, 580 mesh, 590 mesh or 600 mesh, etc., and it can also be any value within 400 - 600 mesh. It should be noted that polishing is performed on both sides of the connector. In some other embodiments, the preprocessing can further include other processing steps, such as degreasing treatment, etc. The degreasing treatment specifically includes heating the alkaline degreasing agent to 80 °C, then immersing the metal part to be plated in the heated alkaline degreasing agent for 30 min, taking it out, cleaning it and drying it; the alkaline degreasing agent includes the following components in the following concentrations: trisodium phosphate 30 g / L - 40 g / L, sodium carbonate 40 g / L - 50 g / L, sodium hydroxide 50 g / L - 60 g / L, sodium silicate 5 g / L - 6 g / L, and the balance is deionized water.

[0052] In some embodiments, the connector includes a stainless - steel connector. Specifically, the stainless - steel connector can be selected from SS430L, SS 441, ZGM, Crofer22APU, etc.

[0053] S2. Mix the raw materials of the coating to be prepared to obtain a mixed material;

[0054] In some embodiments, the raw materials of the coating include Cu and Mn. Cu and Mn can be made into a copper - manganese spinel coating, and the copper - manganese spinel coating has characteristics such as good thermal stability, high electrical conductivity, and appropriate thermal expansion coefficient, making it one of the most effective protective coatings on the surface of stainless - steel connectors.

[0055] In some embodiments, the molar ratio of Cu to Mn is 1:2 to 2:1. Further, the molar ratio of Cu to Mn is 1.5:2 to 3.5:2. Still further, the molar ratio of Cu to Mn is 2:2 to 3:2. Even further, the molar ratio of Cu to Mn is 2.3:2 to 2.7:2. Exemplarily, the molar ratio of Cu to Mn can be 1:2, 1.1:2, 1.2:2, 1.3:2, 1.4:2, 1.5:2, 1.6:2, 1.7:2, 1.8:2, 1.9:2, 2:2, 2.1:2, 2.2:2, 2.3:2, 2.4:2, 2.5:2, 2.6:2, 2.7:2, 2.8:2, 2.9:2, 3:2, 3.1:2, 3.2:2, 3.3:2, 3.4:2, 3.5:2, 3.6:2, 3.7:2, 3.8:2, 3.9:2 or 4:2, etc., and it can also be any value within the range of 2:2 to 3:2.

[0056] S3. Mix the mixture and the organic slurry to obtain a screen printing slurry.

[0057] S4. Print the screen printing slurry onto the connector, and then dry it to convert the screen printing slurry into a precursor material, obtaining a first intermediate with the precursor material attached.

[0058] S5. Perform dry pressing on the precursor material of the first intermediate to reduce the internal voids of the precursor material, obtaining a second intermediate.

[0059] S6. Sinter the second intermediate to convert the precursor material into a coating, completing the preparation.

[0060] This method attaches the mixture of coating raw materials to the connector by screen printing, which is easy to control the composition of the raw materials and the thickness of the attachment, thereby controlling the composition and thickness of the final coating. Then, through dry pressing, the gaps in the precursor material are effectively reduced, thereby increasing the density of the final coating. Finally, the preparation of the coating is achieved through sintering, achieving the purpose of forming a dense, precisely composition-controlled coating that can reach the required thickness.

[0061] The following further elaborates on this application in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate this application and not to limit the scope of this application. The experimental methods without specific conditions noted in the following embodiments are usually determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or the conditions recommended by the manufacturer.

[0062] Example 1

[0063] A method for preparing a coating for a solid oxide fuel cell connector, the method comprising:

[0064] S1. Obtain a connector; the connector is selected from the stainless steel connector SS430L, and both sides of the connector are polished using 500-mesh sandpaper.

[0065] S2. Mix the raw materials Cu and Mn for the coating to be prepared in a molar ratio of 1:1 to obtain a mixed material.

[0066] S3. Mix the mixed material and an organic slurry to obtain a screen printing slurry; wherein, the organic slurry is selected from terpineol.

[0067] S4. Print the screen printing slurry onto the connector, and then dry it to convert the screen printing slurry into a precursor material, obtaining a first intermediate attached with the precursor material; wherein, the drying temperature is 100 °C and the drying time is 30 minutes.

[0068] S5. Perform dry pressing on the precursor material of the first intermediate to reduce the internal voids of the precursor material, obtaining a second intermediate; the pressure of the dry pressing treatment is 200 Mpa.

[0069] S6. Sinter the second intermediate to convert the precursor material into a coating, completing the preparation. The sintering temperature is 900 °C and the sintering time is 2 hours.

[0070] Example 2

[0071] A method for preparing a coating for a solid oxide fuel cell connector, the method comprising:

[0072] S1. Obtain a connector; the connector is selected from the stainless steel connector SS430L, and both sides of the connector are polished using 400-mesh sandpaper.

[0073] S2. Mix the raw materials Cu and Mn for the coating to be prepared in a molar ratio of 1:2 to obtain a mixed material.

[0074] S3. Mix the mixed material and an organic slurry to obtain a screen printing slurry; wherein, the organic slurry is selected from terpineol.

[0075] S4. Print the screen printing slurry onto the connector, and then dry it to convert the screen printing slurry into a precursor material, obtaining a first intermediate attached with the precursor material; wherein, the drying temperature is 80 °C and the drying time is 10 minutes.

[0076] S5. Perform dry pressing on the precursor material of the first intermediate to reduce the internal voids of the precursor material, obtaining a second intermediate; the pressure of the dry pressing treatment is 100 Mpa.

[0077] S6. Sinter the second intermediate to transform the precursor material into a coating, thus completing the preparation. The sintering temperature is 800 °C and the sintering time is 30 minutes.

[0078] The various embodiments of the present application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present application; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the description of the range from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the scope. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0079] In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the drawings. Additionally, in the description of the present application specification, the terms "include", "comprise", etc. mean "including but not limited to". In this text, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In this text, "and / or" describes the associated relationship of associated objects and indicates that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, or B exists alone. Where A and B may be singular or plural. In this text, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items (pieces)", or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or, "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0080] The above description is only the specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for preparing a coating for a solid oxide fuel cell interconnect, characterized in that, The method includes: Obtaining a connector; Mixing the raw materials of the coating to be prepared to obtain a mixed material; Mixing the mixed material and an organic slurry to obtain a screen printing slurry; Printing the screen printing slurry onto the connector and then drying it so that the screen printing slurry is converted into a precursor material to obtain a first intermediate with the precursor material attached; Performing dry pressing on the precursor material of the first intermediate to reduce the internal voids of the precursor material to obtain a second intermediate; Sintering the second intermediate so that the precursor material is transformed into a coating to complete the preparation.

2. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, characterized in that The method further includes: pre-treating the connector.

3. The preparation method of the solid oxide fuel cell interconnect coating according to claim 2, wherein The pre-treatment includes polishing.

4. The method for preparing the solid oxide fuel cell interconnect coating according to claim 3, wherein, The mesh number of the polishing is 400 - 600 mesh.

5. The preparation method of the solid oxide fuel cell interconnect coating according to claim 4, characterized in that, The mesh number of the polishing is 450 - 550 mesh.

6. The method for preparing the solid oxide fuel cell interconnect coating according to claim 5, characterized in that, The mesh number of the polishing is 480 - 520 mesh.

7. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, characterized in that, The raw materials of the coating include Cu and Mn.

8. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, wherein The molar ratio of Cu and Mn is 1:2 - 2:

1.

9. The preparation method of the solid oxide fuel cell interconnect coating according to claim 8, wherein The molar ratio of Cu and Mn is 1.5:2 - 3.5:

2.

10. The preparation method of the solid oxide fuel cell interconnect coating according to claim 9, characterized in that, The molar ratio of Cu and Mn is 2:2 - 3:

2.

11. The method for preparing a solid oxide fuel cell interconnect coating according to claim 10, wherein The molar ratio of Cu and Mn is 1:2 - 1:

1.

12. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, characterized in that, The organic slurry includes terpineol.

13. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, wherein The mixing relationship between the mixed material and the organic slurry satisfies: for example, 0.5 - 1.5 g of the mixed material is dissolved in each milliliter of the organic slurry.

14. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, characterized in that, The drying temperature is 80 - 100 °C; and / or The drying time is 10 - 30 minutes.

15. The method for preparing a solid oxide fuel cell interconnect coating according to claim 14, wherein The drying temperature is 85 - 95 °C; and / or The drying time is 15 - 25 minutes.

16. The method for preparing a solid oxide fuel cell interconnect coating according to claim 1, characterized in that, The pressure of the dry pressing treatment is 100 - 200 Mpa.

17. The method for preparing a solid oxide fuel cell interconnect coating according to claim 16, wherein The pressure of the dry pressing treatment is 130 - 170 Mpa.

18. The preparation method of the solid oxide fuel cell interconnect coating according to claim 1, characterized in that, The sintering temperature is 800 - 900 °C; and / or The sintering time is 0.5 - 2 hours.

19. The method for preparing the solid oxide fuel cell interconnect coating according to claim 18, characterized in that, The sintering temperature is 830 - 870 °C; and / or The sintering time is 1 - 1.5 hours.

20. The preparation method of the solid oxide fuel cell connector coating according to claim 1, characterized in that, The connector includes a stainless steel connector.

Images