Solid oxide fuel cell and method of making same

Abstract

The application provides a solid oxide fuel cell and a preparation method thereof, the solid oxide fuel cell comprises a metal support layer, a transition layer and a cell function layer which are sequentially stacked, the material of the metal support layer comprises a high-temperature alloy, and the thermal expansion coefficient of the transition layer is between the thermal expansion coefficient of the cell function layer and the thermal expansion coefficient of the metal support layer. Therefore, the solid oxide fuel cell of the application can solve the problem that the metal support solid oxide fuel cell cannot normally operate in a high-temperature environment of 1200 DEG C-1300 DEG C.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and specifically to a solid oxide fuel cell and its preparation method. Background Technology

[0002] Solid oxide fuel cells (SOFCs) are power generation devices that can directly convert the chemical energy in fuel into electrical energy. They have advantages such as high power generation efficiency, clean and environmentally friendly operation, and low operating noise. Among them, metal-supported SOFCs are the third generation of solid oxide fuel cells after electrolyte-supported SOFCs and anode-supported SOFCs. They can improve the mechanical strength of the battery, increase the battery's resistance to thermal shock, and reduce system costs. Therefore, in recent years, metal-supported SOFCs have gradually become a new research focus in the field of fuel cells.

[0003] However, existing solid oxide fuel cells cannot operate at high temperatures of 1200℃-1300℃. Summary of the Invention

[0004] The present invention aims to at least partially solve one of the technical problems in the prior art. One object of the present invention is to provide a solid oxide fuel cell that addresses the problem that solid oxide fuel cells cannot operate at high temperatures of 1200°C-1300°C.

[0005] To achieve the above objectives, the first aspect of the present invention provides a solid oxide fuel cell, the solid oxide fuel cell comprising a metal support layer, a transition layer and a battery functional layer stacked sequentially, wherein the metal support layer is made of a high-temperature alloy, and the thermal expansion coefficient of the transition layer is between the thermal expansion coefficient of the battery functional layer and the thermal expansion coefficient of the metal support layer.

[0006] Compared to existing technologies, the present invention offers at least the following advantages: The present invention prepares a transition layer between the battery functional layer and the metal support layer. The addition of the transition layer avoids direct contact between the battery functional layer and the metal support layer. Furthermore, the thermal expansion coefficient of the transition layer lies between that of the battery functional layer and the metal support layer, thus neutralizing the thermal expansion coefficients between them. Therefore, the solid oxide fuel cell of the present invention can solve the problem that solid oxide fuel cells cannot operate at high temperatures of 1200℃-1300℃.

[0007] In some embodiments of the present invention, the coefficient of thermal expansion of the transition layer is 7 × 10⁻⁶. -6 ℃ -1 -15×10 -6 ℃ -1Therefore, solid oxide fuel cells can operate normally at high temperatures of 1200℃-1300℃.

[0008] In some embodiments of the present invention, the coefficient of thermal expansion of the metal support layer is 2 × 10⁻⁶. -6 ℃ -1 -20×10 -6 ℃ -1 This improves the matching of thermal expansion coefficients between the metal support layer and the battery functional layer.

[0009] In some embodiments of the present invention, the battery functional layer includes an anode layer, an electrolyte layer, and a cathode layer sequentially stacked in the direction away from the transition layer. This allows the solid oxide fuel cell to operate normally at high temperatures of 1200°C-1300°C.

[0010] In some embodiments of the present invention, the electrolyte layer is made of zirconium dioxide-based electrolyte or lanthanum gallate-based electrolyte. This improves the matching of thermal expansion coefficients between the metal support layer and the battery functional layer.

[0011] In some embodiments of the present invention, the zirconium dioxide-based electrolyte includes at least one of yttrium oxide-stabilized zirconium oxide, scandium oxide-stabilized zirconium oxide, yttrium oxide, and scandium oxide-stabilized zirconium oxide. This enables the solid oxide fuel cell to operate normally at high temperatures of 1200°C-1300°C.

[0012] In some embodiments of the present invention, the lanthanum gallate-based electrolyte comprises lanthanum, strontium, gallium, and magnesium oxide. This enables the solid oxide fuel cell to operate normally at high temperatures of 1200°C-1300°C.

[0013] In some embodiments of the present invention, the transition layer is made of an alloy. This enhances the high-temperature resistance of the transition layer, thereby enabling the solid oxide fuel cell to operate normally at temperatures of 1200°C-1300°C.

[0014] In some embodiments of the present invention, the alloy includes at least one of NiCrAlY alloy, NiCoCrAlY alloy, and NiAl alloy. This neutralizes the coefficient of thermal expansion between the metal support layer and the battery functional layer, allowing the solid oxide fuel cell to operate normally at high temperatures.

[0015] In some embodiments of the present invention, the thickness of the transition layer is 20 μm-200 μm. This ensures the normal operation of the solid oxide fuel cell under high-temperature conditions.

[0016] In some embodiments of the present invention, the porosity of the transition layer is 10%-50%. This ensures that the solid oxide fuel cell operates normally at high temperatures.

[0017] In some embodiments of the present invention, the high-temperature alloy includes at least one of nickel-based high-temperature alloys, iron-based high-temperature alloys, and titanium alloys. This allows for an increase in the operating temperature of solid oxide fuel cells.

[0018] In some embodiments of the present invention, the nickel-based superalloy includes at least one of GH3536 alloy and GH4169 alloy. This ensures the normal operation of the solid oxide fuel cell under high-temperature conditions.

[0019] The iron-based superalloy includes at least one of MA956 alloy and MA957 alloy. This allows for an increase in the operating temperature of solid oxide fuel cells.

[0020] The titanium alloy includes at least one of TC4 alloy and TA1 alloy. This allows for an increase in the operating temperature of the solid oxide fuel cell.

[0021] A second aspect of this invention provides a method for preparing a solid oxide fuel cell, comprising: preparing a metal support layer; preparing a transition layer on one side of the surface of the metal support layer; and preparing a battery functional layer on the side of the transition layer opposite to the metal support layer. Therefore, the solid oxide fuel cell obtained by this method can solve the problem of mismatched thermal expansion coefficients between the metal support layer and the battery functional layer, enabling the solid oxide fuel cell to operate normally in a high-temperature environment of 1200℃-1300℃.

[0022] In some embodiments of the present invention, the step of fabricating the battery functional layer on the surface of the transition layer opposite to the metal support layer includes: fabricating an anode layer on the surface of the transition layer opposite to the metal support layer; fabricating an electrolyte layer on the surface of the anode layer opposite to the transition layer; and fabricating a cathode layer on the surface of the electrolyte layer opposite to the anode layer. This allows the solid oxide fuel cell to operate normally in a high-temperature environment of 1200℃-1300℃.

[0023] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1A schematic diagram of the structure of a solid oxide fuel cell according to an embodiment of the present invention is shown;

[0026] Figure 2 Showing Figure 1 A schematic diagram of the fabrication process of the solid oxide fuel cell described herein;

[0027] Figure 3 The image shows the cross-sectional morphology of the solid oxide fuel cell of Example 1 after undergoing a thermal cycle at 1200°C.

[0028] Figure 4 The image shows the cross-sectional morphology of the solid oxide fuel cell of Example 2 after undergoing a thermal cycle at 1200°C.

[0029] Figure 5 The cross-sectional morphology of the solid oxide fuel cell in Comparative Example 1 after undergoing thermal cycling at 1200°C is shown.

[0030] Figure 6 The cross-sectional morphology of the solid oxide fuel cell in Comparative Example 2 after undergoing thermal cycling at 1200°C is shown.

[0031] Explanation of reference numerals in the attached figures:

[0032] 1000: Solid oxide fuel cell; 100: Metal support layer; 200: Transition layer; 300: Battery functional layer; 310: Anode layer; 320: Electrolyte layer; 330: Cathode layer. Detailed Implementation

[0033] The embodiments of the technical solution of the present invention are described in detail below. These embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore merely examples and should not be used to limit the scope of protection of the present invention.

[0034] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0035] For the sake of brevity, this article only discloses some specific numerical ranges. However, any lower limit can be combined with any upper limit to form an unspecified range; and any lower limit can be combined with other lower limits to form an unspecified range, just as any upper limit can be combined with any other upper limit to form an unspecified range. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and be combined with any other point or single value or with other lower or upper limits to form an unspecified range.

[0036] In the description of the embodiments of this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the invention, are intended to cover non-exclusive inclusion.

[0038] Metal-supported SOFCs typically employ powder metallurgy or laser drilling to prepare the metal support layer. Then, the anode, electrolyte, and cathode layers are sequentially fabricated on the metal support layer using sintering or thermal spraying methods, thus completing the fabrication of the metal-supported SOFC. However, to prevent large interlayer stresses during battery temperature rise and fall, which could lead to cracking or detachment of the functional layers, it is generally required that the anode, electrolyte, and cathode layers have similar coefficients of thermal expansion to the metal support layer.

[0039] Currently, the metal support layer of metal-supported SOFC is usually made of stainless steel, such as SUS430 stainless steel. However, the long-term operating temperature of stainless steel is generally below 900℃, which cannot provide reliable mechanical support for the battery functional layer in the ultra-high temperature environment of 1200℃. However, when high-temperature alloys with better temperature resistance are used, since the thermal expansion coefficient of high-temperature alloys is usually larger than that of the battery functional layer, large interlayer internal stress will occur during the battery's heating and cooling process, leading to the cracking or detachment of the battery functional layer.

[0040] To address the issue of mismatched thermal expansion coefficients between the metal support layer and the battery functional layer, the first aspect of this invention proposes a solid oxide fuel cell 1000, such as... Figure 1As shown, the solid oxide fuel cell 1000 includes a metal support layer 100, a transition layer 200 and a battery functional layer 300 stacked sequentially. The metal support layer 100 is made of a high-temperature alloy, and the thermal expansion coefficient of the transition layer 200 is between the thermal expansion coefficient of the battery functional layer 300 and the thermal expansion coefficient of the metal support layer 100.

[0041] It should be noted that "the solid oxide fuel cell 1000 includes a metal support layer 100, a transition layer 200, and a battery functional layer 300 stacked sequentially" can be understood as follows: the metal support layer 100 serves as a substrate, the transition layer 200 covers one side surface of the metal support layer 100, and then the battery functional layer 300 covers the side surface of the transition layer 200 facing away from the metal support layer 100. Furthermore, the coefficient of thermal expansion of the transition layer 200 is between that of the battery functional layer 300 and the metal support layer 100; that is, if the coefficient of thermal expansion of the transition layer 200 is 'a', the coefficient of thermal expansion of the battery functional layer 300 is 'b', and the coefficient of thermal expansion of the metal support layer 100 is 'c', then b < a < c. For example, when the coefficient of thermal expansion of the battery functional layer 300 is 11 × 10⁻⁶... -6 ℃ -1 The coefficient of thermal expansion of the metal support layer 100 is 16 × 10⁻⁶. -6 ℃ -1 At that time, the coefficient of thermal expansion of the transition layer 200 can be 12×10⁻⁶. -6 ℃ -1 13×10 -6 ℃ -1 14×10 -6 ℃ -1 Or 15×10 -6 ℃ -1 .

[0042] It should be further explained that the coefficient of thermal expansion (also known as the linear elastic coefficient) is used to represent the degree of expansion or contraction of a material. It is divided into the coefficient of thermal expansion at a specific temperature point and the coefficient of thermal expansion over a temperature range; the latter is called the average coefficient of thermal expansion. The former is the elongation of a unit length of material per degree Celsius increase in temperature; the average coefficient of thermal expansion is the average elongation of a unit length of material over a given temperature range per degree Celsius increase in temperature. In the embodiments of this application, the coefficient of thermal expansion is measured using a push-rod indirect method and a telescope direct reading method.

[0043] The metal support layer 100 is the most fundamental feature of the metal-supported solid oxide fuel cell 1000 compared to the conventional solid oxide fuel cell 1000. The metal support layer 100 has high thermal conductivity, which can significantly reduce the thermal gradient and thermal stress of the solid oxide fuel cell. The metal support layer 100 also has high electrical conductivity, which can improve the electrochemical performance of the solid oxide fuel cell 1000. Currently, the metal support layer 100 is typically made of stainless steel, especially ferritic stainless steel, because ferritic stainless steel forms a chromium oxide passivation layer on its surface when heated, thereby protecting the metal body of the metal support layer and providing a diffusion barrier between the anode layer and the metal body of the metal support layer. However, the long-term operating temperature of stainless steel is generally below 900℃, which also limits the operating temperature of the solid oxide fuel cell 1000.

[0044] When a high-temperature alloy material is used as the metal support layer 100, the thermal expansion coefficient of the high-temperature alloy does not match that of the battery functional layer 300, resulting in cracks between the metal support layer 100 and the battery functional layer 300. Therefore, in some embodiments of the present invention, a transition layer 200 is provided between the metal support layer 100 and the battery functional layer 300. The provision of the transition layer 200 can solve the problem that the solid oxide fuel cell 1000 cannot operate normally in a high-temperature environment.

[0045] It should be noted that high-temperature alloys refer to a class of metallic materials based on iron, nickel, and cobalt, capable of long-term operation at temperatures above 600°C and under certain stress. They possess excellent high-temperature strength, good resistance to oxidation and hot corrosion, and good fatigue performance, fracture toughness, and other comprehensive properties. In this invention, the preparation process of the high-temperature alloy is not specifically limited; casting metallurgy or powder metallurgy processes can be used, as long as the prepared high-temperature alloy can withstand temperatures of 1200°C or higher, it falls within the scope of this invention.

[0046] like Figure 1As shown, the solid oxide fuel cell 1000 includes a metal support layer 100, a transition layer 200, and a battery functional layer 300 stacked sequentially. The thermal expansion coefficient of the transition layer 200 is between that of the battery functional layer 300 and the metal support layer 100. To address the problem that solid oxide fuel cells cannot operate at high temperatures of 1200℃-1300℃, this invention forms a transition layer 200 between the battery functional layer 300 and the metal support layer 100. The transition layer 200 avoids direct contact between the metal support layer 100 and the battery functional layer 300. Furthermore, since the thermal expansion coefficient of the transition layer 200 is between that of the battery functional layer 300 and the metal support layer 100, the transition layer 200 can neutralize the thermal expansion coefficients between the metal support layer 100 and the battery functional layer 300. Therefore, the solid oxide fuel cell 1000 of the present invention can solve the problem of mismatch in thermal expansion coefficients between the metal support layer 100 and the battery functional layer 300, enabling the solid oxide fuel cell 1000 to operate normally in a high-temperature environment of 1200℃-1300℃.

[0047] In addition to satisfying the above conditions, the solid oxide fuel cell of the present invention may also optionally satisfy one or more of the following conditions to further improve the problem of mismatch in the coefficients of thermal expansion between the metal support layer 100 and the battery functional layer 300.

[0048] In some embodiments, the coefficient of thermal expansion of the transition layer 200 is 7 × 10⁻⁶. -6 ℃ -1 -15×10 -6 ℃ -1 For example, 8×10 -6 ℃ -1 -14×10 -6 ℃ -1 9×10 -6 ℃ -1 -13×10 -6 ℃ -1 10×10 -6 ℃ -1 -12×10 -6 ℃ -1 In some embodiments, the coefficient of thermal expansion of the metal support layer 100 is 2 × 10⁻⁶. -6 ℃ -1 -20×10 -6 ℃ -1 For example, 4×10 -6 ℃ -1 -18×10 -6 ℃ -1 6×10-6 ℃ -1 -12×10 -6 ℃ -1 8×10 -6 ℃ -1 -10×10 -6 ℃ -1 Therefore, the coefficient of thermal expansion of the transition layer 200 is between that of the metal support layer 100 and the battery functional layer 300. The provision of the transition layer 200 can solve the problem of mismatch in the coefficients of thermal expansion between the metal support layer 100 and the battery functional layer 300, thereby ensuring that the solid oxide fuel cell 1000 can operate normally in a high-temperature environment.

[0049] Furthermore, the metal support layer 100 can be porous, and the porosity of the metal support layer 100 is not particularly limited. According to some embodiments of the present invention, the porosity of the metal support layer 100 can be 15%-40%, for example, 16%-35%, 18%-30%, 20%-30%, etc. When the porosity of the metal support layer 100 is within the above range, the operating temperature of the solid oxide fuel cell 1000 can be increased while ensuring the normal operation of the solid oxide fuel cell 1000.

[0050] It should be noted that porosity refers to the number of pores present on a unit surface of an electroplated layer, that is, the number of channels of varying sizes extending from the plating surface to the base metal. Commonly used methods for determining porosity include the filter paper method, the immersion method, and the paste method.

[0051] In some implementations, such as Figure 1 As shown, the battery functional layer 300 includes an anode layer 310, an electrolyte layer 320, and a cathode layer 330 sequentially stacked in the direction away from the transition layer 200. The battery functional layer 300 typically includes an anode layer 310, an electrolyte layer 320, and a cathode layer 330. The battery functional layer 300 is an important site for redox reactions in the solid oxide fuel cell 1000. Fuel gases such as hydrogen (H2) flow into contact with the anode layer 310 facing the solid electrolyte layer 320, and oxidant gases such as air or oxygen (O2) flow into contact with the cathode layer 330 facing the opposite side of the electrolyte layer 320. Oxygen ions (O2) generated in the cathode layer 330... 2- It moves along the solid electrolyte layer 320 and reaches the anode layer 310, in the fuel electrode layer O 2- It reacts with H2 to produce electricity through an electrochemical reaction.

[0052] Specifically, when air flows on the cathode layer 330 side and fuel flows on the anode layer 310 side, the oxygen in the air is converted into oxygen ions near the interface between the cathode layer 330 and the solid electrolyte layer 320. These oxygen ions then pass through the solid electrolyte layer 320 to the anode layer 310. Furthermore, the fuel gas reacts with the oxygen ions to produce water and carbon dioxide. These reactions are represented by equations (1), (2), and (3). By connecting the cathode layer 330 and the anode layer 310 with an external circuit, electricity can be output to the outside.

[0053] H2+O 2- →H₂O + 2e - (1)

[0054] CO+O 2- →CO2 + 2e - (2)

[0055] 1 / 2O2+2e - →O 2- (3)

[0056] In some embodiments of the present invention, the anode layer 310 is disposed on the side surface of the transition layer 200 opposite to the metal support layer 100. The anode layer 310 serves as the anode of the solid oxide fuel cell 1000 in the subsequent electrochemical oxidation process, and an oxidation reaction occurs between the fuel gas and oxygen ions at the anode. The present invention does not specifically limit the thickness of the anode layer 310. According to some embodiments of the present invention, the thickness of the anode layer 310 can be 10μm-100μm, for example, 15μm-95μm, 20μm-90μm, 25μm-80μm, 30μm-70μm, 40μm-60μm, 45μm-50μm, etc. When the thickness of the anode layer 310 is within the above range, the high-temperature resistance of the solid oxide fuel cell 1000 is improved while ensuring the normal operation of the solid oxide fuel cell 1000.

[0057] The present invention does not particularly limit the porosity of the anode layer 310. According to some embodiments of the present invention, the porosity of the anode layer 310 can be 10%-50%, for example, 15%-45%, 20%-40%, 25%-35%, etc. When the porosity of the anode layer 310 is less than 10%, the effective gas diffusion and migration channels of the anode layer 310 are reduced, thereby affecting the normal operation of the solid oxide fuel cell 1000. When the porosity of the anode layer 310 is greater than 50%, the effective conductive volume of the anode layer 310 will be reduced, thereby affecting the operating voltage of the solid oxide fuel cell 1000. When the porosity of the anode layer 310 is 10%-50%, it is beneficial for gas to diffuse and migrate in the pores of the anode layer 310, and at the same time, it improves the high temperature resistance of the solid oxide fuel cell 1000.

[0058] In some embodiments, the electrolyte layer 320 is made of at least one of zirconium dioxide-based electrolyte and lanthanum gallate-based electrolyte. The electrolyte layer 320 is a core component of the solid oxide fuel cell, and its performance directly determines the performance of the solid oxide fuel cell 1000. Zirconia-based electrolyte and lanthanum gallate-based electrolyte have high ionic conductivity, good structural and chemical stability, and are therefore ideal solid electrolyte materials.

[0059] In some embodiments, the zirconium dioxide-based electrolyte includes at least one of yttrium oxide-stabilized zirconium oxide, scandium oxide-stabilized zirconium oxide, and yttrium oxide and scandium oxide-stabilized zirconium oxide. Doping zirconium oxide with yttrium oxide and scandium oxide separately, or with both yttrium oxide and scandium oxide, yields yttrium oxide-stabilized zirconium oxide (YSZ), scandium oxide-stabilized zirconium oxide (ScSZ), and yttrium oxide and scandium oxide-stabilized zirconium oxide, enabling the solid oxide fuel cell 1000 to operate normally in high-temperature environments.

[0060] In some embodiments, the lanthanum gallate-based electrolyte comprises lanthanum strontium gallium magnesium oxide (LSGM). LSGM has the chemical formula La. 0.8 Sr 0.2 Ga 0.8 Mg 0.2 O 3-x LSGM is a ceramic electrolyte material with high ionic conductivity. Therefore, using LSGM as the electrolyte layer enables the solid oxide fuel cell 1000 to operate normally in high-temperature environments.

[0061] The present invention does not specifically limit the thickness of the electrolyte layer 320. According to some embodiments of the present invention, the thickness of the electrolyte layer 320 can be 10μm-200μm, for example, it can be 20μm-180μm, 40μm-160μm, 60μm-140μm, 80μm-100μm, etc. Within the above range of electrolyte layer 320 thickness, the high temperature resistance performance of the solid oxide fuel cell 1000 can be improved.

[0062] This invention does not specifically limit the porosity of the electrolyte layer 320. According to some embodiments of the invention, the porosity of the electrolyte layer 320 is less than 1%, for example, it can be 0-0.9%, 0.2%-0.8%, 0.4%-0.6%, etc. When the porosity is greater than 1%, it will cause gas leakage on both sides of the cathode layer 330 and anode layer 310 of the solid oxide fuel cell 1000, resulting in a reduction in the partial pressure of the gas in the cathode layer 330 and anode layer 310, thereby reducing the open-circuit voltage of the solid oxide fuel cell 1000. When the porosity of the electrolyte layer 320 is less than 1%, the electrochemical performance of the solid oxide fuel cell 1000 can be guaranteed, while also improving the high-temperature resistance of the solid oxide fuel cell 1000.

[0063] In the solid oxide fuel cell 1000, the cathode layer 330 serves as the cathode of the solid oxide fuel cell in the subsequent electrochemical oxidation process, and a cathode reaction in which oxygen gains electrons to generate oxygen ions occurs at the cathode. The present invention does not specifically limit the thickness of the cathode layer 330. According to some embodiments of the present invention, the thickness of the cathode layer 330 can be 10μm-100μm, for example, 20μm-90μm, 30μm-80μm, 45μm-75μm, 50μm-60μm, etc. Within the above-mentioned thickness range of the cathode layer 330, the solid oxide fuel cell 1000 can be guaranteed to operate normally in the temperature range of 1200℃-1300℃.

[0064] This invention does not specifically limit the porosity of the cathode layer 330. According to some embodiments of the invention, the porosity of the cathode layer 330 can be 10%-50%, for example, 15%-45%, 20%-40%, 25%-35%, etc. When the porosity of the cathode layer 330 is less than 10%, the effective gas diffusion and migration channels of the cathode layer 330 are reduced, thereby affecting the performance of the solid oxide fuel cell 1000. When the porosity of the cathode layer 330 is greater than 50%, the effective conductive volume of the cathode layer 330 is reduced, thereby affecting the operating voltage of the solid oxide fuel cell 1000. When the porosity of the cathode layer 330 is 10%-50%, it is beneficial for gas to diffuse and migrate in the pores of the cathode layer 330. Therefore, the problem that the solid oxide fuel cell 1000 cannot operate normally in high-temperature environments can be solved.

[0065] In some embodiments, the transition layer 200 is made of an alloy material, which has excellent electrical conductivity and temperature resistance, ensuring that the solid oxide fuel cell can operate normally in high-temperature environments.

[0066] Furthermore, in some embodiments, the alloy includes at least one of NiCrAlY alloy, NiCoCrAlY alloy, and NiAl alloy. These materials are adhesive layer materials, serving to resist oxidation and corrosion and to match the coefficients of thermal expansion. Thus, the transition layer 200 formed using any of the aforementioned alloy materials can promote a match in the coefficients of thermal expansion between the metal support layer 100 and the battery functional layer 300.

[0067] Specifically, the main phase of the NiCrAlY alloy is γ′-Ni3Al / γ-Ni, with a small amount of β-NiAl phase. Under high-temperature conditions, the formation of a dense alumina layer on the surface of the transition layer 200 prepared from the NiCrAlY alloy helps to slow down the oxidation rate and provides good protection for the metal support layer. The NiCrAlY alloy has good plasticity, high high-temperature strength, and excellent oxidation and corrosion resistance, making it an ideal material for the transition layer 200 in thermal barrier coating systems. Due to the long-range ordered crystal structure and the coexistence of metallic and covalent bonds, the NiAl alloy possesses a series of unique and excellent properties, such as high melting point, low density, high thermal conductivity, and excellent oxidation resistance. Currently, methods for preparing these alloys include arc spraying, electroplating, plasma spraying, and flame spraying.

[0068] In this invention, there is no special limitation on the size of the transition layer 200. As long as it is compatible with the size of the solid oxide fuel cell 1000, it is within the scope of this invention. In some embodiments, the thickness of the transition layer 200 is 20μm-200μm, for example, it can be 20μm-190μm, 30μm-180μm, 40μm-170μm, 50μm-160μm, 60μm-150μm, 70μm-140μm, 80μm-130μm, 90μm-120μm, 100μm-110μm, etc. When the thickness of the transition layer 200 is within the above range, it can make the coefficients of thermal expansion between the metal support layer 100 and the battery functional layer 300 match, so that the solid oxide fuel cell 1000 can operate at high temperature.

[0069] According to the working principle of the solid oxide fuel cell 1000, the internal structure of the solid oxide fuel cell needs to allow gas diffusion. Therefore, the transition layer 200 has a porous structure. The present invention does not specifically limit the porosity of the transition layer 200. In some embodiments, the porosity of the transition layer 200 is 10%-50%, for example, it can be 15%-45%, 20%-40%, 25%-35%, etc. In this way, it can be ensured that the gas diffuses in the solid oxide fuel cell 1000, and the solid oxide fuel cell 1000 can also operate normally in a high temperature environment of 1200℃-1300℃.

[0070] In some embodiments, the high-temperature alloy includes at least one of nickel-based high-temperature alloys, iron-based high-temperature alloys, and titanium alloys. The aforementioned high-temperature alloy materials possess excellent high-temperature resistance, and using these materials as the metal support layer 100 can increase the operating temperature of the solid oxide fuel cell 1000.

[0071] Furthermore, in some embodiments, the nickel-based superalloy includes at least one of GH3536 alloy and GH4169 alloy. It should be noted that GH3536 alloy is a nickel-based superalloy with a high iron content, primarily strengthened by chromium and molybdenum solid solution. GH3536 alloy can withstand certain stresses at high temperatures of 600℃-1200℃ and possesses oxidation or corrosion resistance. GH4169 alloy is a precipitation-strengthened nickel-based superalloy with good fatigue resistance, radiation resistance, oxidation resistance, corrosion resistance, as well as good processing and welding properties. In the embodiments of the present invention, the preparation process of the above alloys is not specifically limited; any alloy material that can withstand temperatures above 1200℃ is considered part of the inventive concept. Therefore, the use of the above alloys enables the solid oxide fuel cell 1000 to operate normally in high-temperature environments.

[0072] In some embodiments, the iron-based high-temperature alloy includes at least one of MA956 alloy and MA957 alloy. It should be noted that the chemical composition of MA956 alloy is 67% nickel, 28% molybdenum, 1% iron, 1% chromium, and small amounts of copper, manganese, silicon, and titanium. It possesses high high-temperature strength, good oxidation and corrosion resistance, and excellent fatigue performance and fracture toughness. MA956 alloy is a special high-temperature alloy formed by mechanical alloying (MA) to achieve a uniform dispersion of ultra-stable oxide-reinforcing phases within the alloy matrix at high temperatures. Therefore, the use of the above alloy enables the solid oxide fuel cell 1000 to operate normally in high-temperature environments.

[0073] In some embodiments, the titanium alloy includes at least one of TC4 alloy and TA1 alloy. It should be noted that TC4 alloy is a medium-strength α-β type two-phase titanium alloy containing 6% α-stabilizing element aluminum and 4% β-stabilizing element vanadium. This alloy possesses good comprehensive mechanical properties and excellent stability at high temperatures. TA1 alloy is an α-structure titanium alloy with excellent stamping and welding properties, and also exhibits excellent stability at high temperatures. In the embodiments of the present invention, the preparation process of the above alloys is not particularly limited; any alloy material that can withstand temperatures above 1200°C is considered part of the inventive concept. Therefore, the use of the above alloys enables the solid oxide fuel cell 1000 to operate normally in high-temperature environments.

[0074] A second aspect of the present invention provides a method for preparing a solid oxide fuel cell. Figure 2 This is an embodiment of the method for preparing a solid oxide fuel cell according to the present invention. The method for preparing a solid oxide fuel cell includes:

[0075] S100: Preparation of the metal support layer;

[0076] The metal support layer is the most fundamental feature of metal-supported solid oxide fuel cells compared to traditional solid oxide fuel cells. The metal support layer has high thermal conductivity, which can greatly reduce the thermal gradient and thermal stress of solid oxide fuel cells. The metal support layer also has high electrical conductivity, which can improve the electrochemical performance of solid oxide fuel cells.

[0077] Specifically, the present invention does not impose any particular limitation on the preparation method of the metal support layer. In some embodiments of the present invention, the metal support layer can be obtained by processes such as thin plate laser processing, chemical etching, and powder metallurgy.

[0078] S200: A transition layer is prepared on the surface of one side of the metal support layer;

[0079] According to some embodiments of the present invention, a transition layer is disposed on one side surface of the metal support. The aforementioned transition layer serves as a connector between the metal support layer and the battery functional layer, and the thermal expansion coefficient of the transition layer is between the thermal expansion coefficient of the battery functional layer and the thermal expansion coefficient of the metal support layer, thereby solving the problem of thermal expansion coefficient mismatch between the metal support layer and the battery functional layer.

[0080] Specifically, the present invention does not particularly limit the preparation method of the transition layer. For example, the transition layer can be obtained by atmospheric plasma spraying. That is, by using a powder supply system, the transition layer material powder is fed into the core of the high-temperature and high-speed plasma flame generated by the spray gun. Under the action of the high-temperature and high-speed flame, the powder will quickly turn into molten droplets and accelerate. Finally, it will impact the metal support layer and cool and solidify into molten droplets. The molten droplets will continuously deposit on the metal support layer to form the transition layer. The transition layer obtained by plasma spraying can reduce the interfacial reaction between the metal support layer material and the transition layer material and improve the bonding force between the transition layer and the metal support layer.

[0081] S300: A battery functional layer is prepared on the surface of the transition layer on the side opposite to the metal support layer.

[0082] According to some embodiments of the present invention, the battery functional layer is disposed on the side surface of the transition layer opposite to the metal support layer, that is, the transition layer is placed between the metal support layer and the battery functional layer, avoiding direct contact between the metal support layer and the battery functional layer. The transition layer can act as a neutralizer to neutralize the coefficient of thermal expansion between the metal support layer and the battery functional layer, thereby solving the problem that solid oxide fuel cells cannot operate normally in high-temperature environments of 1200℃-1300℃.

[0083] Step S300 includes S301, S302 and S303.

[0084] S301: An anode layer is prepared on the surface of the transition layer opposite to the metal support layer;

[0085] According to some embodiments of the present invention, the anode layer is disposed on the side surface of the transition layer opposite to the metal support layer. The aforementioned anode layer serves as the anode of the solid oxide fuel cell in the subsequent electrochemical oxidation process, and the fuel gas and oxygen ions undergo an oxidation reaction at the anode.

[0086] Specifically, the present invention does not particularly limit the preparation method of the anode layer. For example, the anode layer can be obtained by atmospheric plasma spraying process, that is, by using a powder supply system to send the anode layer material powder into the core of the high temperature and high speed plasma flame generated by the spray gun. Under the action of the high temperature and high speed flame, the powder will quickly turn into molten droplets and accelerate, and finally impact the transition layer to cool and solidify into molten droplets. The molten droplets are continuously deposited on the transition layer to form the anode layer. The anode layer obtained by plasma spraying process can reduce the interfacial reaction between the transition layer material and the anode layer material and improve the bonding force between the anode layer and the transition layer.

[0087] S302: An electrolyte layer is prepared on the surface of the anode layer opposite to the transition layer;

[0088] According to some embodiments of the present invention, the electrolyte layer plays a role in isolating oxygen and fuel in a solid oxide fuel cell. Specifically, the present invention does not particularly limit the preparation method of the electrolyte layer. For example, the electrolyte layer can be obtained by atmospheric plasma spraying. The electrolyte layer obtained by the aforementioned process can reduce the interfacial reaction between the electrolyte layer material and the anode layer material and improve the bonding force between the anode layer and the electrolyte layer.

[0089] S303: A cathode layer is prepared on the side of the electrolyte layer opposite to the anode layer.

[0090] According to some embodiments of the present invention, in a solid oxide fuel cell, the cathode layer serves as the cathode of the solid oxide fuel cell in the subsequent electrochemical oxidation process, and a cathode reaction in which oxygen gains electrons to generate oxygen ions occurs at the cathode. Specifically, the preparation process of the cathode layer is not particularly limited. For example, a supersonic flame spraying method can be preferred. The spraying flame of supersonic flame spraying is a strongly oxidizing atmosphere, which can effectively prevent the cathode layer material powder from changing its crystal phase structure during the spraying process. At the same time, the flame temperature of supersonic flame spraying is relatively low, which makes it easy for the cathode layer material powder to form a semi-molten state where the surface melts while the core remains solid, thereby increasing the porosity of the cathode layer and improving the performance of the assembled battery.

[0091] According to some embodiments of the present invention, the preparation process of the anode layer and the cathode layer may further include one of magnetron sputtering, chemical vapor deposition, vacuum plasma spraying and cold spraying.

[0092] To make the technical problems, technical solutions, and beneficial effects solved by the embodiments of the present invention clearer, the following will provide a more detailed description in conjunction with the embodiments and accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0093] Example 1

[0094] (1) A GH3536 alloy metal support layer was prepared by powder metallurgy, and its coefficient of thermal expansion was 16×10⁻⁶. -6 ℃ -1 The outer diameter of the metal support layer is 20mm, the thickness is 1mm, the length is 50mm, and the porosity is 25%.

[0095] (2) A NiCrAlY alloy transition layer was prepared on one side surface of the GH3536 alloy metal support layer by atmospheric plasma spraying, and its coefficient of thermal expansion was 13×10. -6 ℃ -1 The spraying power was 20kW, the spraying distance was 135mm, the spraying thickness was 40μm, and the porosity of the NiCrAlY alloy transition layer prepared by spraying was 15%.

[0096] (3) Ni / YSZ alloy anode layer was prepared by atmospheric plasma spraying on the side of NiCrAlY alloy transition layer away from GH3536 alloy metal support layer. The spraying power was 25kW, the spraying distance was 120mm, the spraying thickness was 30μm, and the porosity of the Ni / YSZ alloy anode layer prepared by spraying was 20%.

[0097] (4) A YSZ electrolyte layer was prepared by atmospheric plasma spraying on the side of the Ni / YSZ alloy anode layer away from the NiCrAlY alloy transition layer. The spraying power was 60kW, the spraying distance was 80mm, the spraying thickness was 100μm, and the porosity of the YSZ electrolyte layer prepared by spraying was less than 1%.

[0098] (5) An LSCF cathode layer was prepared by supersonic flame spraying on the side of the YSZ electrolyte layer away from the NiCrAlY alloy transition layer. The oxygen flow rate was 150 NL / min, the propane flow rate was 70 NL / min, the spraying distance was 130 mm, the spraying thickness was 50 μm, and the porosity of the LSCF cathode layer prepared by spraying was 25%.

[0099] Example 2

[0100] (1) The MA956 alloy metal support layer is produced by powder metallurgy, and its coefficient of thermal expansion is 14×10⁻⁶. -6 ℃ -1 The outer diameter of the metal support layer is 20 mm, the thickness is 1 mm, the length is 50 mm, and the porosity is 25%.

[0101] (2) A NiCrAlY alloy transition layer was prepared on one side of the MA956 alloy metal support layer by atmospheric plasma spraying, and its coefficient of thermal expansion was 13×10⁻⁶. -6 ℃ -1 The spraying power was 20kW, the spraying distance was 135mm, the spraying thickness was 40μm, and the porosity of the NiCrAlY alloy transition layer prepared by spraying was 15%.

[0102] (3) Ni / YSZ anode layer was prepared by atmospheric plasma spraying on the side of the NiCrAlY alloy transition layer away from the MA956 alloy metal support layer. The spraying power was 25kW, the spraying distance was 120mm, the spraying thickness was 30μm, and the porosity of the Ni / YSZ anode layer prepared by spraying was 20%.

[0103] (4) A YSZ electrolyte layer was prepared by atmospheric plasma spraying on the side of the Ni / YSZ anode layer away from the NiCrAlY alloy transition layer. The spraying power was 60kW, the spraying distance was 80mm, the spraying thickness was 100μm, and the porosity of the YSZ electrolyte layer prepared by spraying was less than 1%.

[0104] (5) An LSCF cathode layer was prepared by supersonic flame spraying on the side of the YSZ electrolyte layer away from the Ni / YSZ anode layer. The oxygen flow rate was 150 NL / min, the propane flow rate was 70 NL / min, the spraying distance was 130 mm, the spraying thickness was 50 μm, and the porosity of the LSCF cathode layer prepared by spraying was 25%.

[0105] Comparative Example 1

[0106] (1) A SUS430 stainless steel metal support layer was prepared by powder metallurgy, and its coefficient of thermal expansion was 12×10⁻⁶. -6 ℃ -1 The SUS430 stainless steel metal support layer has an outer diameter of 20mm, a thickness of 1mm, a length of 50mm, and a porosity of 25%.

[0107] (2) A NiCrAlY alloy transition layer was prepared on one side of the SUS430 stainless steel metal support layer by atmospheric plasma spraying, and its coefficient of thermal expansion was 13×10⁻⁶. -6 ℃ -1 The spraying power was 20kW, the spraying distance was 135mm, the spraying thickness was 40μm, and the porosity of the NiCrAlY alloy transition layer prepared by spraying was 15%.

[0108] (3) Ni / YSZ anode layer was prepared by atmospheric plasma spraying on the side of NiCrAlY alloy transition layer away from SUS430 stainless steel metal support layer. The spraying power was 25kW, the spraying distance was 120mm, the spraying thickness was 30μm, and the porosity of the Ni / YSZ anode layer prepared by spraying was 20%.

[0109] (4) A YSZ electrolyte layer was prepared by atmospheric plasma spraying on the side of the Ni / YSZ anode layer away from the NiCrAlY alloy transition layer. The spraying power was 60kW, the spraying distance was 80mm, the spraying thickness was 100μm, and the porosity of the YSZ electrolyte layer prepared by spraying was less than 1%.

[0110] (5) An LSCF cathode layer was prepared by supersonic flame spraying on the side of the YSZ electrolyte layer away from the Ni / YSZ anode layer. The oxygen flow rate was 150 NL / min, the propane flow rate was 70 NL / min, the spraying distance was 130 mm, the spraying thickness was 50 μm, and the porosity of the LSCF cathode layer prepared by spraying was 25%.

[0111] Comparative Example 2

[0112] (1) A GH3536 alloy metal support layer was prepared by powder metallurgy, and its coefficient of thermal expansion was 16×10⁻⁶. -6 ℃ -1The GH3536 alloy metal support layer has an outer diameter of 20mm, a thickness of 1mm, a length of 50mm, and a porosity of 25%.

[0113] (2) Ni / YSZ anode layer was prepared on one side of the GH3536 alloy metal support layer by atmospheric plasma spraying. The spraying power was 25kW, the spraying distance was 120mm, the spraying thickness was 30μm, and the porosity of the Ni / YSZ anode layer prepared by spraying was 20%.

[0114] (3) A YSZ electrolyte layer was prepared by atmospheric plasma spraying on the side of the Ni / YSZ anode layer away from the GH3536 alloy metal support layer. The spraying power was 60kW, the spraying distance was 80mm, the spraying thickness was 100μm, and the porosity of the YSZ electrolyte layer prepared by spraying was less than 1%.

[0115] (4) An LSCF cathode layer was prepared by supersonic flame spraying on the side of the YSZ electrolyte layer away from the Ni / YSZ anode layer. The oxygen flow rate was 150 NL / min, the propane flow rate was 70 NL / min, the spraying distance was 130 mm, the spraying thickness was 50 μm, and the porosity of the LSCF cathode layer prepared by spraying was 25%.

[0116] Examples 3-6 follow the same process as Example 1, with the differences shown in Table 1.

[0117] Table 1

[0118]

[0119] Battery performance test

[0120] Observation of battery cross-sectional morphology: Using a metallographic cutter, the battery was cut into sample pieces of approximately 0.5cm x 0.5cm along its cross-sectional direction. The sample pieces were then placed with the battery functional layer cross-section facing down into a cylindrical mold. Resin was slowly poured into the mold until the sample pieces were completely submerged. After about 24 hours, the resin was allowed to completely solidify, completing the battery sample mounting. The resin sample with the battery sample pieces mounted was polished with sandpaper. The polishing surface was the side of the resin sample containing the battery functional layer cross-section. Sandpaper with grits of 120, 240, 600, 800, 1200, and 2000 grits was used for polishing in sequence to complete the sample preparation. The sample was then placed in a scanning electron microscope to observe the cross-sectional morphology of the battery.

[0121] Ohmic impedance and polarization impedance tests of the battery at different operating temperatures: Taking Example 1 as an example, a metal current collector was welded to both ends of the metal support of the sprayed transition layer and the battery functional layer using argon arc welding. Silver wire was wound around the end of the current collector, and silver paste was applied to the contact position to improve the electrical contact between the current collector wire and the current collector. During the test, the end of the current collector extended out of the high-temperature electric furnace, thereby achieving current collection in the low-temperature zone on the anode side of the battery. For current collection on the cathode side of the battery, platinum wire was wound around the surface of the cathode functional layer, and platinum paste was applied to the contact position between the platinum wire and the cathode to improve the electrical contact. During the test, the current collectors of the battery anode and cathode were first connected to the electrochemical workstation using the four-terminal method. Then, hydrogen gas was supplied to the inside of the tubular battery (anode side) through the metal current collector at a flow rate of 200 sccm. The cathode side of the battery was directly exposed to the furnace chamber, and air was provided to the battery cathode through natural convection inside the electric furnace. The electric furnace was programmed to heat to 1200℃ at a rate of 5℃ / min. During the heating process, the open-circuit voltage of the battery was monitored. Once the battery temperature reached 1200℃, the electrochemical impedance spectroscopy of the battery was measured using an electrochemical workstation under open-circuit voltage conditions. The test frequency was 100kHz-0.1Hz. The intercept of the electrochemical impedance spectroscopy in the high-frequency region with the real axis is the ohmic impedance of the battery. The difference between the intercepts in the low-frequency and high-frequency regions with the real axis is the polarization impedance of the battery.

[0122] The testing procedures for the solid oxide fuel cells in Examples 2-6 and Comparative Examples 1-2 are the same as above.

[0123] The performance test results of the solid oxide fuel cells in each embodiment and comparative example are shown in Table 2.

[0124] Table 2

[0125]

[0126]

[0127] In conclusion, as shown in Table 2, in Examples 1 to 6 of this invention, when the operating temperature of the solid oxide fuel cell is increased from 700℃ to 1200℃, all the dynamic characteristics of the cell are normal. The increase in electrolyte conductivity significantly reduces the ohmic impedance of the cell, and the reaction kinetic characteristics of the cell electrodes are also significantly improved, reducing the polarization impedance of the cell. Therefore, the power generation of a single cell is significantly improved. Compared with the solid oxide fuel cells prepared in Comparative Examples 1-2, the power density of the solid oxide fuel cell proposed in this invention, which can operate at 1200℃, is significantly improved, thereby reducing the weight of the cell itself and enabling it to be used as an auxiliary power unit in mobile scenarios such as spacecraft.

[0128] also, Figure 3The cross-sectional topography of the solid oxide fuel cell of Example 1 after undergoing thermal cycling at 1200°C is shown. As can be seen from the figure, due to the presence of the NiCrAlY transition layer, the battery still maintains good contact after undergoing thermal cycling at 1200°C, and no failure phenomena such as functional layer cracking or detachment occur. Figure 4 The cross-sectional topography of the solid oxide fuel cell of Example 2 after undergoing thermal cycling at 1200°C is shown. As can be seen from the figure, due to the presence of the NiCrAlY transition layer, the battery still maintains good contact after undergoing thermal cycling at 1200°C, and no failure phenomena such as functional layer cracking or detachment occur. Figure 5 The cross-sectional morphology of the solid oxide fuel cell in Comparative Example 1 after undergoing thermal cycling at 1200℃ is shown. It can be seen from the figure that SUS430 stainless steel cannot provide good mechanical support for the battery in the ultra-high temperature environment of 1200℃, which leads to longitudinal cracks in the battery electrolyte under thermal stress and causes battery failure. Figure 6 The figure shows the cross-sectional morphology of the solid oxide fuel cell in Comparative Example 2 after thermal cycling at 1200°C. As can be seen from the figure, due to the significant difference in thermal expansion coefficients between the battery functional layer and the metal support, and the absence of a transition layer, the battery functional layer detaches from the metal support surface during heating, causing battery failure. Therefore, the solid oxide fuel cell provided by this invention solves the problem of mismatched thermal expansion coefficients between the metal support layer and the battery functional layer, enabling the solid oxide fuel cell to operate in ultra-high temperature environments of 1200°C-1300°C.

[0129] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," "some implementations," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0130] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A solid oxide fuel cell, characterized in that, The solid oxide fuel cell comprises a metal support layer, a transition layer, and a battery functional layer stacked sequentially. The metal support layer is made of a high-temperature alloy, and the coefficient of thermal expansion of the transition layer is between that of the battery functional layer and the metal support layer. The porosity of the transition layer is 10%-50%; The transition layer is made of an alloy. The alloy includes at least one of NiCrAlY alloy, NiCoCrAlY alloy, and NiAl alloy; The high-temperature alloy includes at least one of nickel-based high-temperature alloys, iron-based high-temperature alloys, and titanium alloys; The solid oxide fuel cell satisfies at least one of the following conditions: The nickel-based superalloy includes at least one of GH3536 alloy and GH4169 alloy; The iron-based superalloy includes at least one of MA956 alloy and MA957 alloy; The titanium alloy includes at least one of TC4 alloy and TA1 alloy.

2. The solid oxide fuel cell according to claim 1, characterized in that, The solid oxide fuel cell satisfies at least one of the following conditions: The coefficient of thermal expansion of the transition layer is 7×10. -6 ℃ -1 -15×10 -6 ℃ -1 ; The coefficient of thermal expansion of the metal support layer is 2×10⁻⁶. -6 ℃ -1 -20×10 -6 ℃ -1 .

3. The solid oxide fuel cell according to claim 1, characterized in that, The battery functional layer includes an anode layer, an electrolyte layer, and a cathode layer stacked sequentially in the direction away from the transition layer.

4. The solid oxide fuel cell according to claim 3, characterized in that, The electrolyte layer is made of at least one of zirconium dioxide-based electrolyte and lanthanum gallate-based electrolyte.

5. The solid oxide fuel cell according to claim 4, characterized in that, The zirconium dioxide-based electrolyte includes at least one of yttrium oxide-stabilized zirconium oxide, scandium oxide-stabilized zirconium oxide, yttrium oxide, and scandium oxide-stabilized zirconium oxide.

6. The solid oxide fuel cell according to claim 4, characterized in that, The lanthanum gallate-based electrolyte comprises lanthanum, strontium, gallium, and magnesium oxide.

7. The solid oxide fuel cell according to claim 1, characterized in that, The solid oxide fuel cell satisfies: The thickness of the transition layer is 20 μm-200 μm.

8. A method for preparing a solid oxide fuel cell according to any one of claims 1-7, characterized in that, include: Preparation of metal support layer; A transition layer is prepared on the surface of one side of the metal support layer; A battery functional layer is prepared on the surface of the transition layer opposite to the metal support layer.

9. The method according to claim 8, characterized in that, The step of fabricating the battery functional layer on the surface of the transition layer opposite to the metal support layer includes: An anode layer is prepared on the surface of the transition layer opposite to the metal support layer; An electrolyte layer is prepared on the surface of the anode layer opposite to the transition layer; A cathode layer is prepared on the side of the electrolyte layer opposite to the anode layer.

Images