Metal supported sofc and method of making the same and fuel cell

Abstract

The application discloses a metal-supported SOFC and a preparation method and fuel cell thereof, and the method comprises the following steps: (1) sintering an electrolyte slurry to obtain an electrolyte layer; (2) sleeving the electrolyte layer on the inner side of a ring-shaped fastener, and the ring-shaped fastener is used for supporting the electrolyte layer and preventing the electrolyte layer from deforming; (3) spraying an anode material on at least part of the surface of the electrolyte layer to form an anode layer; (4) spraying a metal support material on the side of the anode layer away from the electrolyte layer to form a metal support layer; and (5) spraying a cathode material on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer. Compared with a sintering method, the method avoids problems such as falling off and cracking of functional layers of the metal-supported SOFC, mutual diffusion of Ni in the anode and Fe and Cr elements in the metal support, and Ni coarsening; compared with a thermal spraying method, the method significantly increases the density of the electrolyte layer, and avoids a post-processing procedure for the electrolyte layer.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of fuel cells, and particularly relates to a metal-supported SOFC, a preparation method thereof and a fuel cell. BACKGROUND

[0002] A solid oxide fuel cell (SOFC) is a power generation device capable of directly converting chemical energy in fuel into electrical energy, and has the advantages of high power generation efficiency, environmental protection, low operation noise, etc. A metal-supported SOFC uses a porous alloy as a metal support, and has higher robustness, thermal shock resistance and thermal conductivity compared to a ceramic support solution, which is conducive to rapid startup of the cell and improvement of temperature uniformity during operation of the cell.

[0003] Currently, the preparation process of the metal-supported SOFC mainly includes sintering and thermal spraying. The sintering method is the main preparation process of the metal-supported SOFC. In order to make the electrolyte achieve a fully dense structure, long-time sintering at an ultra-high temperature of 1000 DEG C or above is usually required. For example, the sintering temperature of the most commonly used YSZ electrolyte is generally above 1400 DEG C. However, there is no high-temperature alloy that can withstand such a high sintering temperature in an oxidizing atmosphere. Therefore, the electrolyte sintering process needs to be in an inert or reducing atmosphere. In addition, since the electrolyte is usually co-sintered with the anode, problems such as cracking and peeling of the functional layer, mutual diffusion of Ni in the anode and Fe and Cr in the metal support, and Ni coarsening may occur during high-temperature sintering. The traditional solution is to add sintering aids such as cobalt oxide and lithium oxide to the electrolyte slurry to reduce the sintering temperature of the electrolyte. However, the addition amount of the sintering aid is very strict, and the addition of the sintering aid usually causes a decrease in the electrical conductivity of the electrolyte, which is not conducive to the improvement of the performance of the cell.

[0004] The metal-supported SOFC prepared by thermal spraying is prepared by using thermal spraying technology to spray anode, electrolyte and cathode functional layers on a metal support in sequence to realize the preparation of the metal-supported SOFC. The coating prepared by the thermal spraying process is formed by the continuous stacking of a series of flat particles, which includes some larger pores, uncombined interfaces between layers and vertical cracks in the single layer structure, and can form through pores for gas diffusion, so that the preparation of a high-performance porous electrode can be relatively easily realized based on the thermal spraying method, but at the same time, it is difficult to realize the complete densification of the electrolyte layer, which is the main problem of the metal-supported SOFC prepared by the thermal spraying method. The atmospheric plasma spraying and vacuum plasma spraying are two main thermal spraying processes for preparing the electrolyte of the metal-supported SOFC, in which the atmospheric plasma spraying has low equipment cost and operation cost, but the prepared electrolyte has low density, and needs to be treated by a post-processing method such as immersion to improve the density of the electrolyte, however, due to the low concentration of the effective components (such as zirconium nitrate and yttrium nitrate) in the solution, the solid formed after evaporation of the solvent is small, so in order to realize sufficient density, multiple immersion is needed, the process flow is long, which offsets the advantage of fast preparation of the plasma spraying itself; although the density of the electrolyte layer prepared by the vacuum plasma spraying can meet the needs of the metal-supported SOFC, the main problem of the process is high equipment cost and operation cost, and the price of a complete set of vacuum plasma spraying equipment is usually more than 10 million yuan, and the start-stop cost of a single device is also much higher than that of atmospheric plasma spraying, which is not conducive to the commercial application of the metal-supported SOFC. SUMMARY

[0005] The present application aims to at least partially solve one of the problems in the related art. To this end, one object of the present application is to provide a metal-supported SOFC and a preparation method and fuel cell thereof. Compared with the sintering method, the preparation method of the present application does not need to sinter the anode layer, the metal support layer and the cathode layer, thereby avoiding the preparation of the metal-supported SOFC under inert gas or reducing gas, significantly reducing the operation cost, and avoiding the problems of peeling and cracking of the functional layer, mutual diffusion of Ni in the anode and Fe and Cr elements in the metal support, and Ni coarsening; compared with the thermal spraying method, the density of the electrolyte layer prepared by the preparation method of the present application is significantly increased, and the post-processing process of the electrolyte layer is avoided, thereby significantly reducing the operation cost.

[0006] In one aspect of the present application, the present application provides a method for preparing a metal-supported SOFC. In the embodiments of the present application, the method comprises:

[0007] (1) sintering the electrolyte slurry to obtain an electrolyte layer;

[0008] (2) the electrolyte layer is sleeved inside a ring-shaped fastener, an outer peripheral structure of the electrolyte layer matches an inner peripheral structure of the ring-shaped fastener, and the ring-shaped fastener is used to support the electrolyte layer and prevent the electrolyte layer from being deformed;

[0009] (3) an anode material is sprayed on at least part of a surface of the electrolyte layer to form an anode layer;

[0010] (4) a metal support material is sprayed on a side of the anode layer away from the electrolyte layer to form a metal support layer;

[0011] (5) a cathode material is sprayed on at least part of a surface of the electrolyte layer away from the anode layer to form a metal support SOFC.

[0012] According to the method for preparing a metal support SOFC in the embodiments of the present application, the electrolyte layer is obtained by high-temperature sintering of electrolyte slurry alone, which can ensure that the obtained electrolyte layer has good compactness; the electrolyte layer is sleeved inside a ring-shaped fastener, an outer peripheral structure of the electrolyte layer matches an inner peripheral structure of the ring-shaped fastener, the ring-shaped fastener can support the electrolyte layer from the side to prevent the electrolyte layer from being broken on the side in subsequent processing, and the presence of the ring-shaped fastener can improve the bonding strength of the metal support layer at the edge position to prevent the metal support layer from being warped and falling off in subsequent spraying; the metal support material is sprayed on a side of the anode layer away from the electrolyte layer, and part of the metal support layer can be combined with the ring-shaped fastener, thereby avoiding warping and falling off of the metal support layer in subsequent spraying; and the cathode material is sprayed on at least part of a surface of the electrolyte layer away from the anode layer to avoid electrical contact between the anode layer and the cathode layer and thus short circuit. Compared with the sintering method alone, the preparation method of the present application does not need to sinter the anode layer, the metal support layer and the cathode layer, thereby avoiding preparation of the metal support SOFC in an inert gas or a reducing gas, significantly reducing the operation cost, and avoiding problems such as falling off and cracking of the functional layer, mutual diffusion of Ni in the anode and Fe and Cr elements in the metal support body, and Ni coarsening. Compared with the thermal spraying method alone, the compactness of the electrolyte layer prepared by the preparation method of the present application is significantly increased, the post-processing process of the electrolyte layer is avoided, and the operation cost is significantly reduced.

[0013] In addition, the method for preparing a metal support SOFC according to the above embodiments of the present application can also have the following additional technical features:

[0014] In some embodiments of the present application, the material of the ring-shaped fastener is the same as that of the metal support layer.

[0015] In some embodiments of the present application, the material of the metal support layer comprises at least one of Fe-based alloy, Ni-based alloy and Cr-based alloy.

[0016] In some embodiments of the present application, step (3) further comprises, before the anode material is sprayed on at least part of the surface of the electrolyte layer, setting a spraying protection tool on the annular fastener to ensure that the anode layer is formed only on the surface of the electrolyte layer.

[0017] In some embodiments of the present application, before the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer, the side of the electrolyte layer away from the anode layer is polished to a thickness of 10-50 microns of the electrolyte layer.

[0018] In some embodiments of the present application, step (5) further comprises, before the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer, setting a spraying protection tool on the annular fastener to ensure that the cathode layer is formed only on the surface of the electrolyte layer.

[0019] In some embodiments of the present application, in step (1), the sintering temperature is 1400-1500℃.

[0020] In some embodiments of the present application, in step (1), the thickness of the electrolyte layer is 100-1000 microns, preferably 250-500 microns.

[0021] In some embodiments of the present application, in step (2), the thickness of the electrolyte layer is equal to the thickness of the annular fastener, and the inner circumferential length of the annular fastener is greater than the outer circumferential length of the electrolyte layer.

[0022] In some embodiments of the present application, in step (2), the difference between the inner circumferential length of the annular fastener and the outer circumferential length of the electrolyte layer ranges from 3.14 to 6.28 mm.

[0023] In some embodiments of the present application, in step (2), during the process of setting the electrolyte layer inside the annular fastener, the gap between the electrolyte layer and the annular fastener is brazed to achieve a fastening connection between the electrolyte layer and the annular fastener.

[0024] In some embodiments of the present application, the material of the electrolyte layer comprises at least one of YSZ, ScSZ, GDC, LSGM, BZCYYb and BZCY.

[0025] In some embodiments of the present application, in step (3), the material of the anode layer comprises at least one of Ni / YSZ and Ni / GDC.

[0026] In some embodiments of the present application, in step (3), the method of spraying the anode material on at least part of the surface of the electrolyte layer comprises at least one of atmospheric plasma spraying, high velocity oxy-fuel spraying and cold spraying.

[0027] In some embodiments of the present application, in step (4), the method of spraying the support material on the side of the anode layer away from the electrolyte layer comprises at least one of atmospheric plasma spraying, high velocity oxy-fuel spraying and cold spraying.

[0028] In some embodiments of the present application, in step (5), the material of the cathode layer comprises at least one of LSM, LSCF and LSC.

[0029] In some embodiments of the present application, in step (5), the method of spraying the cathode material on at least part of the surface of the electrolyte layer away from the anode layer comprises at least one of atmospheric plasma spraying, high velocity oxy-fuel spraying and cold spraying.

[0030] In some embodiments of the present application, the density of the electrolyte layer in the metal-supported SOFC is not less than 99%.

[0031] In still another aspect of the present application, the present application provides a metal-supported SOFC, which is prepared by the method of preparing a metal-supported SOFC according to the embodiments of the present application. Thus, the metal-supported SOFC has good electrolyte layer density, can effectively isolate the cathode side atmosphere and the anode side atmosphere of the metal-supported SOFC, so as to keep the metal-supported SOFC at a high open circuit voltage, and realize high efficiency conversion of fuel chemical energy to electrical energy.

[0032] In a third aspect of the present application, the present application provides a fuel cell. According to the embodiments of the present application, the fuel cell has a metal-supported SOFC prepared by the method described in the above embodiments. Thus, the fuel cell has all the advantages of the metal-supported SOFC described above, which will not be repeated here.

[0033] Additional aspects and advantages of the present application will be in part apparent and in part pointed out hereinafter. BRIEF DESCRIPTION OF DRAWINGS

[0034] The above and / or additional aspects and advantages of the present application will become apparent and be readily appreciated from the following description, including the appended drawings.

[0035] Figure 1 is a flow chart of a method of manufacturing a metal-supported SOFC according to an embodiment of the present application;

[0036] Figure 2 is a flow chart of a method of manufacturing a metal-supported SOFC according to an embodiment of the present application;

[0037] Figure 3 is a top view of a cell formed according to Example 1 of the present application;

[0038] Figure 4 is a graph showing the open circuit voltage of a cell formed according to Example 1 of the present application and a cell formed according to Comparative Example 1 of the present application at different temperatures;

[0039] Figure 5 is a SEM image of the electrolyte layer according to Example 1 of the present application;

[0040] Figure 6 is a SEM image of the electrolyte layer according to Comparative Example 1 of the present application;

[0041] Figure 7 is a top view of a cell formed according to Comparative Example 2 of the present application;

[0042] Figure 8 is a top view of a cell formed according to Comparative Example 3 of the present application.

[0043] Reference Signs:

[0044] 1 - electrolyte layer; 2 - annular fastener; 3 - inner region of the annular fastener; 4 - brazing paste; 5 - anode layer; 6 - metal support layer; 7 - cathode layer. DETAILED DESCRIPTION

[0045] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or like reference numerals refer to the same or like elements throughout. The embodiments described below are exemplary and are intended to explain the present application, and are not to be understood as limiting the present application.

[0046] The present application proposes a method of manufacturing a metal-supported SOFC. According to an embodiment of the present application, with reference to the accompanying drawings of Figure 1 and Figure 2 , the method comprises the following operation steps:

[0047] S100: sintering the electrolyte slurry to obtain an electrolyte layer

[0048] In this step, the electrolyte slurry is sintered to obtain the electrolyte layer. The electrolyte layer 1 is obtained by high-temperature sintering of the electrolyte slurry alone using existing mature sintering technology, which can ensure that the obtained electrolyte layer has good density.

[0049] In one embodiment of the present application, in step S100, the electrolyte slurry includes electrolyte material, sintering aid, film processing slurry additive, and organic solvent, wherein the sintering aid includes but is not limited to at least one of Co2O3, Li2O, Bi2O3, and B2O3, the film processing slurry additive includes but is not limited to at least one of glycerol, polyvinyl butyral, dibutyl phthalate, and lauryl sulfate, and the organic solvent includes but is not limited to at least one of methyl ketone, ethanol solution, acetone, and deionized water.

[0050] According to another embodiment of the present application, in step S100, the method of sintering the electrolyte slurry includes air environment direct sintering, vacuum sintering, and protective atmosphere sintering; preferably air environment direct sintering.

[0051] According to another embodiment of the present application, in step S100, the sintering temperature is 1400-1500℃, whereby by controlling the sintering temperature within the above range, it is ensured that the electrolyte layer obtained by sintering has good density, meeting the needs of customers. It should be noted that the sintering temperature can be specifically selected according to the actual electrolyte layer to be sintered.

[0052] According to another embodiment of the present application, in step S100, the thickness of the electrolyte layer is 100-1000 microns, preferably 250-500 microns, whereby by controlling the thickness of the electrolyte layer within the above range, it is ensured that the electrolyte layer is not easily broken during subsequent spraying, and it is also conducive to better polishing of the electrolyte layer in the subsequent process, achieving precise control of the thickness of the electrolyte layer.

[0053] In the embodiments of the present application, the structure of the electrolyte layer is not specifically limited, and those skilled in the art can select it according to actual needs. As a specific example, the structure of the electrolyte layer is a cylinder.

[0054] In the embodiments of the present application, the material of the electrolyte layer is not specifically limited, and those skilled in the art can select it according to actual needs. As a specific example, the material of the electrolyte layer includes at least one of YSZ, ScSZ, GDC, LSGM, BZCYYb, and BZCY.

[0055] S200: The electrolyte layer is sleeved inside the annular fastener

[0056] In this step, the electrolyte layer 1 is sleeved inside the annular fastener 2, the outer peripheral structure of the electrolyte layer matches the inner peripheral structure of the annular fastener, and the electrolyte layer is completely in the inner region 3 of the annular fastener. The annular fastener can not only play a role of side support for the electrolyte layer to prevent the electrolyte layer from being broken on the side in the subsequent processing process, but also can improve the bonding strength of the metal support layer at the edge position to prevent the metal support layer from being warped and separated in the subsequent spraying process.

[0057] According to another specific embodiment of the present application, in step S200, the thickness of the electrolyte layer is equal to the thickness of the annular fastener, and the inner peripheral circumference of the annular fastener is greater than the outer peripheral circumference of the electrolyte layer. Thus, the electrolyte layer can be better clamped inside the annular fastener, so as to ensure that the edge part of the electrolyte layer is not easily broken.

[0058] According to another specific embodiment of the present application, in step S200, the difference between the inner peripheral circumference of the annular fastener and the outer peripheral circumference of the electrolyte layer is 3.14-6.28 mm. Thus, the difference between the inner peripheral circumference of the annular fastener and the outer peripheral circumference of the electrolyte layer is limited within the above range, which ensures that the annular fastener can better fix the electrolyte layer, and avoids that the inner peripheral circumference of the annular fastener is too close to the outer peripheral circumference of the electrolyte layer, so that the electrolyte layer is not easily clamped in the inner region of the annular fastener or the annular fastener causes the edge part of the electrolyte layer to be broken.

[0059] According to another specific embodiment of the present application, in step S200, the gap between the electrolyte layer and the annular fastener is filled with brazing paste 4 during the process of sleeving the electrolyte layer inside the annular fastener. Thus, the fastening connection between the electrolyte layer and the annular fastener is further facilitated, and the annular fastener will not cause the edge part of the electrolyte layer to be broken.

[0060] In the embodiment of the present application, in step S200, the material of the annular fastener is not particularly limited, and can be selected according to actual needs by those skilled in the art. As a specific example, the material of the annular fastener includes at least one of Fe-based alloy, Ni-based alloy and Cr-based alloy.

[0061] S300: Spraying an anode material on at least part of the surface of the electrolyte layer to form an anode layer

[0062] In this step, the anode material is sprayed on at least part of the surface of the electrolyte layer to form the anode layer 5. It needs to be explained that the anode material can be sprayed on the surface of the electrolyte layer to form the anode layer, or can be sprayed on part of the area of the edge of the annular fastener, as long as the subsequent metal material support material can be sprayed on part of the area of the edge of the annular fastener.

[0063] According to another specific embodiment of the present application, step S300 further comprises, before the anode material is sprayed on at least part of the surface of the electrolyte layer, arranging a spraying protection tool on the annular fastener to ensure that the anode layer is formed only on at least part of the surface of the electrolyte layer, thereby ensuring that the subsequent metal material support material can be sprayed on part of the area of the edge of the annular fastener, the metal support layer can have a high bonding strength with the annular fastener, and the internal stress of the metal support layer is avoided from being too large, causing the metal support layer to warp and fall off from the edge during the spraying process.

[0064] In the embodiment of the present application, in step S300, the type of the spraying protection tool is not particularly limited, and persons skilled in the art can select according to actual needs. As a specific example, the spraying protection tool is a high-temperature adhesive tape.

[0065] In the embodiment of the present application, in step S300, the material of the anode layer is not particularly limited, and persons skilled in the art can select according to actual needs. As a specific example, the material of the anode layer includes at least one of Ni / YSZ and Ni / GDC.

[0066] In the embodiment of the present application, in step S300, the method of spraying the anode material on at least part of the surface of the electrolyte layer is not particularly limited, and persons skilled in the art can select according to actual needs. As a specific example, the method of spraying the anode material on at least part of the surface of the electrolyte layer includes at least one of atmospheric plasma spraying, high-velocity oxy-fuel spraying, and cold spraying; preferably atmospheric plasma spraying, thereby not only ensuring that the bonding strength inside the anode layer is large, but also enabling the anode layer to have a high bonding strength with the electrolyte layer.

[0067] According to another specific embodiment of the present application, in step S300, the atmospheric plasma spraying method is used to spray the anode material on at least part of the surface of the electrolyte layer to form the anode layer, the spraying power is 20-40 kW, the spraying distance is 60-180 mm, and the spraying thickness is 20-40 microns, thereby ensuring that the anode layer can be sprayed on at least part of the surface of the electrolyte layer and the spraying effect is good.

[0068] S400: Spraying a metal material support material on the side of the anode layer away from the electrolyte layer to form a metal support layer

[0069] In this step, the metal support material is sprayed on the side of the anode layer away from the electrolyte layer to form the metal support layer 6. The spraying area of the metal support material includes the surface of the anode layer away from the electrolyte layer and part of the area of the annular fastener. The metal support layer has a high bonding strength with the annular fastener, thereby avoiding excessive internal stress of the metal support layer and easily causing warping and falling off of the metal support layer from the edge during the spraying process.

[0070] In the embodiment of the present application, in step S400, the material of the metal support layer is not particularly limited and can be selected according to actual needs by those skilled in the art. As a specific example, the material of the metal support layer includes at least one of Fe-based alloy, Ni-based alloy and Cr-based alloy.

[0071] In the embodiment of the present application, in step S400, the method for spraying the metal support material on the side of the anode layer away from the electrolyte layer to form the metal support layer is not particularly limited. As a specific example, the method for spraying the metal support material on the side of the anode layer away from the electrolyte layer to form the metal support layer includes at least one of atmospheric plasma spraying, high-velocity oxy-fuel spraying and cold spraying. Preferably, the high-velocity oxy-fuel spraying method is used. The spraying flame temperature of the high-velocity oxy-fuel spraying is relatively low, which easily makes the metal support material powder form a semi-molten state with a surface layer melting and an inner core remaining in a solid state, thereby improving the porosity of the metal support layer, facilitating the diffusion of gas in the metal support layer and improving the performance of the assembled battery.

[0072] According to another specific embodiment of the present application, in step S400, the high-velocity oxy-fuel spraying method is used to spray the metal support material on the side of the anode layer away from the electrolyte layer to form the metal support layer. The oxygen flow rate is 100-200 NL / min, the propane flow rate is 50-100 NL / min, the spraying distance is 100-150 mm and the spraying thickness is 0.2-5 mm. The preferred range of the spraying thickness is 0.5-1 mm. Thus, the spraying area of the metal support material further includes the surface of the anode layer away from the electrolyte layer and part of the area of the annular fastener and the spraying effect is good.

[0073] According to another specific embodiment of the present application, the material of the annular fastener is similar to the thermal expansion coefficient, the thermal conductivity and the elastic modulus of the material of the metal support layer. Thus, the metal support layer can have a high bonding strength with the annular fastener and the internal stress of the metal support layer is not excessive, which avoids warping and falling off of the metal support layer from the edge during the spraying process.

[0074] According to another specific embodiment of the present application, the material of the annular fastener is the same as the material of the metal support layer, thereby further ensuring that the metal support layer and the annular fastener have high bonding strength, so as to avoid excessive internal stress of the metal support layer and to prevent the metal support layer from being warped and peeled off from the edge during the spraying process.

[0075] S500: Spraying a cathode material on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer

[0076] In this step, the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer 7, so as to form a metal support SOFC. Forming the cathode layer only on at least part of the surface of the electrolyte layer away from the anode layer avoids the cathode material being sprayed on the annular fastener, thereby causing a short circuit of the fuel cell formed subsequently, and ensuring the safe use of the fuel cell.

[0077] According to another specific embodiment of the present application, the step S500 further comprises, before the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer, polishing the side of the electrolyte layer away from the anode layer to a thickness of 10-50 microns. Due to the presence of the annular fastener and the metal support, the electrolyte layer is well mechanically supported, and can effectively prevent the electrolyte layer from being broken during polishing. Thus, the thickness of the electrolyte layer is precisely controlled, and the performance of the fuel cell prepared subsequently is significantly improved.

[0078] In the embodiments of the present application, the method for polishing the electrolyte layer in the step S500 is not particularly limited, and can be selected according to actual needs by those skilled in the art. As a specific example, the method for polishing the electrolyte layer can include physical polishing and chemical polishing.

[0079] According to another specific embodiment of the present application, in the step S500, the side of the electrolyte layer away from the anode layer is etched by a strong acid, and then the electrolyte layer is polished to expose the electrolyte layer at the etching interface, so as to polish the electrolyte layer.

[0080] According to another specific embodiment of the present application, the step S500 further comprises, before the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer, setting a spraying protection tool on the annular fastener, thereby further ensuring that the cathode layer is formed only on at least part of the surface of the electrolyte layer, avoiding the cathode material being sprayed on the annular fastener, thereby causing a short circuit of the fuel cell formed subsequently, and ensuring the safe use of the fuel cell.

[0081] In the embodiment of the present application, the type of the protective coating spraying tool in step S500 is not particularly limited, and can be selected by those skilled in the art according to actual needs. As a specific example, the protective coating spraying tool is a high-temperature adhesive tape.

[0082] In the embodiment of the present application, the material of the cathode layer in step S500 is not particularly limited, and can be selected by those skilled in the art according to actual needs. As a specific example, the material of the cathode layer includes at least one of LSM, LSCF, and LSC.

[0083] In the embodiment of the present application, the method for spraying the cathode material on at least part of the surface of the electrolyte layer away from the anode layer in step S500 is not particularly limited, and as a specific example, the method for spraying the cathode material on at least part of the surface of the electrolyte layer away from the anode layer includes at least one of atmospheric plasma spraying, high-velocity oxy-fuel spraying, and cold spraying. Preferably, the method is high-velocity oxy-fuel spraying. The spraying flame of high-velocity oxy-fuel spraying is a strong oxidizing atmosphere, which can effectively prevent the crystal structure of the cathode layer material powder from changing during spraying. In addition, the flame temperature of high-velocity oxy-fuel spraying is relatively low, which can easily make the cathode layer material powder form a semi-molten state with a surface layer melting and an inner core remaining solid, thereby improving the porosity of the cathode layer and being beneficial to improving the performance of the assembled battery.

[0084] According to another specific embodiment of the present application, the cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer by high-velocity oxy-fuel spraying. During spraying, the oxygen flow rate is 200-250 NL / min, the propane flow rate is 50-80 NL / min, the spraying distance is 120-180 mm, and the spraying thickness is 20-40 microns. Therefore, the cathode layer is further formed only on at least part of the surface of the electrolyte layer, and the cathode material is prevented from being sprayed on the annular fastener, thereby avoiding short circuit of the fuel cell formed subsequently and ensuring the safe use of the fuel cell.

[0085] According to another specific embodiment of the present application, the density of the electrolyte layer in the metal-supported SOFC is not less than 99%. The density of the electrolyte layer prepared by a thermal spraying method alone is usually 94%-96%. Therefore, the density of the electrolyte layer prepared by the preparation method of the present application is significantly increased, the post-processing procedures such as multiple impregnation of the electrolyte layer are avoided, the process flow is significantly reduced, and the operation cost is reduced.

[0086] According to another specific embodiment of the present application, the electrical conductivity of the electrolyte layer of the metal-supported SOFC is significantly improved compared to the electrical conductivity of the electrolyte layer of the metal-supported SOFC prepared by using the sintering method (adding sintering aids), thereby further improving the performance of the cell and realizing high efficiency conversion of fuel chemical energy to electrical energy.

[0087] The method for preparing the metal-supported SOFC according to the embodiments of the present application has at least one of the following advantages:

[0088] 1. Compared to using the sintering method alone, the preparation method of the present application does not need to sinter the anode layer, the metal support layer and the cathode layer, thereby avoiding the preparation of the metal-supported SOFC under inert gas or reducing gas, significantly reducing the operating cost, and also avoiding the problems of delamination and cracking of the functional layer, mutual diffusion of Ni in the anode and Fe, Cr elements in the metal support, and Ni coarsening, etc.

[0089] 2. Compared to using the sintering method (adding sintering aids), the electrical conductivity of the metal-supported SOFC prepared by using the preparation method of the present application is significantly increased, thereby further improving the performance of the cell and realizing high efficiency conversion of fuel chemical energy to electrical energy.

[0090] 3. Compared to using the thermal spraying method alone, the density of the electrolyte layer prepared by using the preparation method of the present application is significantly increased, avoiding multiple post-processing procedures such as impregnation of the electrolyte layer, significantly reducing the process flow and reducing the operating cost.

[0091] 4. By setting the thermal expansion coefficient, thermal conductivity and elastic modulus of the annular fastener material to be similar to those of the metal support layer material, it is ensured that the metal support layer can have a very high bonding strength with the annular fastener, and the internal stress of the metal support layer is also avoided from being too large, which causes the metal support layer to warp and fall off from the edge during the spraying process.

[0092] In another aspect of the present application, a metal-supported SOFC is provided. According to the embodiments of the present application, the metal-supported SOFC is prepared by using the method for preparing the metal-supported SOFC described in the above embodiments. Therefore, the metal-supported SOFC has good electrolyte layer density, can effectively isolate the cathode side atmosphere and the anode side atmosphere of the metal-supported SOFC, thereby maintaining a high open circuit voltage of the metal-supported SOFC and realizing high efficiency conversion of fuel chemical energy to electrical energy.

[0093] In a third aspect of the present application, a fuel cell is provided. According to the embodiments of the present application, the fuel cell has the metal-supported SOFC prepared by using the method described in the above embodiments. Therefore, the fuel cell has all the advantages of the metal-supported SOFC described above, which will not be repeated here.

[0094] Embodiments of the present application are described in detail below, it should be noted that the embodiments described below are exemplary, only for the purpose of explaining the present application, and can not be understood as a limitation of the present application. In addition, if not specifically stated, all reagents used in the following examples are commercially available or can be synthesized according to the methods described herein or known methods, and the reaction conditions not listed are also readily available to those skilled in the art.

[0095] Example 1

[0096] A method for preparing a metal-supported SOFC, the steps are as follows:

[0097] (1) The electrolyte powder, sintering aid, thin film process slurry additive and organic solvent are mixed to obtain an electrolyte slurry, wherein the electrolyte powder is YSZ, the sintering aid is Co2O3, the thin film process slurry additive is glycerol, and the organic solvent is ethanol, the mass ratio of the above-mentioned electrolyte powder, sintering aid, thin film process slurry additive and organic solvent is 85:2:8:5, the electrolyte slurry is sintered at high temperature to obtain a circular YSZ electrolyte layer with a thickness of 500 microns and a diameter of 20 mm, the sintering temperature is 1400℃, and the sintering time is 8h;

[0098] (2) The electrolyte layer is sleeved inside the annular fastener, the outer peripheral structure of the electrolyte layer matches the inner peripheral structure of the annular fastener, wherein the annular fastener has a thickness of 500 microns, an inner diameter of 22mm and an outer diameter of 42mm, and is made of SUS430 stainless steel (iron-based alloy), and the gap between the above-mentioned electrolyte layer and the above-mentioned annular fastener is filled with brazing paste for brazing;

[0099] (3) The anode material is sprayed on the surface of the electrolyte layer to form an anode layer, wherein the anode material is Ni / YSZ, the spraying process selects atmospheric plasma spraying, the spraying power is 25kW, the spraying distance is 120mm, and the spraying thickness is 30 microns, and a high-temperature adhesive tape is used to protect the surface of the annular fastener during the spraying process, so that the spraying area of the anode is limited to the surface of the electrolyte;

[0100] (4) The metal support material is sprayed on the side of the anode layer away from the electrolyte layer to form a metal support layer, wherein the metal support layer material is SUS430 stainless steel (iron-based alloy), the spraying process selects supersonic flame spraying, the oxygen flow rate is 150NL / min, the propane flow rate is 70NL / min, the spraying distance is 130mm, and the spraying thickness is 0.75mm, and the spraying area includes the surface of the entire anode layer away from the electrolyte layer and the surface of the annular fastener on the same side;

[0101] (5) spraying a cathode material on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer, wherein the cathode material is LSCF, the spraying process is selected to be supersonic flame spraying, the oxygen flow rate is 220 NL / min, the propane flow rate is 65 NL / min, the spraying distance is 150 mm, the spraying thickness is 30 microns, and a high-temperature adhesive tape is used to protect the surface of the annular fastener during the spraying process, so that the spraying area of the cathode is limited to the surface of the electrolyte, and the cathode is prevented from being sprayed onto the annular fastener to cause short circuit of the battery.

[0102] The appearance (metal support body side) of the battery assembled by using the above process is shown in FIG. 1, and it can be seen that the metal support body is well combined with the adjacent functional layers, and no edge warping or falling off occurs. Figure 3 The open-circuit voltage of the above battery at different temperatures is shown in FIG. 2, and the open-circuit voltage of the above battery is close to the theoretical value, which indicates that the density of the electrolyte layer is good, and no battery gas leakage occurs. Figure 4 The SEM image of the above electrolyte layer is shown in FIG. 3, and the density of the electrolyte layer is 99.5%, which effectively isolates the cathode atmosphere and the anode atmosphere of the battery. Figure 5 The conductivity of the electrolyte layer of the battery at 800°C is 0.021 S / cm.

[0103] Example 2

[0104] The method for preparing the metal-supported SOFC provided in this embodiment is different from that in Example 1 only in that:

[0105] The side of the electrolyte layer obtained in step (4) away from the anode layer is physically polished to a thickness of 50 microns, and then a cathode material is sprayed on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer.

[0106] The other contents are the same as in Example 1.

[0107] The battery prepared by this embodiment has a good appearance, the metal support body is well combined with the adjacent functional layers, and no edge warping or falling off occurs; the density of the electrolyte layer prepared by this embodiment reaches 99.8%; and the conductivity of the battery prepared by this embodiment is basically the same as that of the battery prepared in Example 1.

[0108] Example 3

[0109] The method for preparing the metal-supported SOFC provided in this embodiment is different from that in Example 1 only in that:

[0110] The metal support layer material is SUS316 stainless steel (iron-based alloy).

[0111] The other contents are the same as in Example 1.

[0112] The battery prepared by the present example has good appearance and morphology, and the metal support is well combined with the adjacent functional layer without edge warping or falling off. The density of the electrolyte layer prepared by the present example reaches 99.1%. The conductivity of the battery prepared by the present example is basically consistent with that of the battery prepared by Example 1.

[0113] Comparative Example 1

[0114] The present comparative example provides a method for preparing a metal-supported SOFC, and the difference between the present example and Example 1 is only that:

[0115] (1) The YSZ electrolyte layer is prepared on the surface of a circular stainless steel sheet with a diameter of 20 mm and a thickness of 1 mm by atmospheric plasma spraying, the spraying power is 60 kW, the spraying distance is 80 mm, and the spraying thickness is 500 microns. After spraying, the stainless steel sheet with the YSZ electrolyte layer is placed in hydrochloric acid for 24 hours to completely dissolve the stainless steel sheet in the hydrochloric acid, and a circular YSZ electrolyte layer with a diameter of 20 mm and a spraying thickness of 500 microns is obtained based on the atmospheric plasma spraying process.

[0116] The other contents are the same as those of Example 1.

[0117] The above-prepared battery (metal-supported SOFC) is tested, and the open-circuit voltage of the above battery at different temperatures is as shown in Figure 4 The open-circuit voltage of the above battery is lower than the theoretical value, indicating that the electrolyte layer of the battery has insufficient density, thereby causing the battery to leak; the SEM image of the above electrolyte layer is as shown in Figure 6 It can be seen that the electrolyte layer prepared by the atmospheric plasma spraying process has a large number of pores inside, and the density of the electrolyte layer is 95.7%, causing the battery to leak. After testing the above battery, it is found that the electrolyte layer of the battery has an electrical conductivity of 0.016 S / cm at 800°C.

[0118] Comparative Example 2

[0119] The present comparative example provides a method for preparing a metal-supported SOFC, and the difference between the present example and Example 1 is only that:

[0120] Step (2) of Example 1 is not included;

[0121] The other contents are the same as those of Example 1.

[0122] The appearance and morphology of the battery prepared by Comparative Example 2 are as shown in Figure 7 It can be seen that the edge of the metal support layer has obviously warped and fallen off during the spraying process, which ultimately leads to a significant decrease in the performance of the battery.

[0123] Comparative Example 3

[0124] The present comparative example provides a method for preparing a metal-supported SOFC, which is different from Example 1 only in that:

[0125] The metal support layer material is NiCrAlY;

[0126] The other contents are the same as those in Example 1.

[0127] The appearance of the cell prepared in Comparative Example 3 is shown in FIG. 2, and the metal support layer at the edge of the cell is completely detached. Figure 8 As the metal support layer and the ring-shaped fastener are dissimilar materials, the thermal expansion coefficient, the thermal conductivity coefficient and the elastic modulus of the two materials are quite different, and thus the interfacial bonding strength between the metal support layer and the ring-shaped fastener is low, which leads to the warping of the edge of the metal support layer during the spraying process and the complete detachment of the metal support layer.

[0128] Although the embodiments of the present application have been shown and described above, it should be understood by those skilled in the art that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application.

Claims

1. A method of making a metal supported SOFC, characterized by, The method comprises: (1) sintering an electrolyte slurry to obtain an electrolyte layer; (2) setting the electrolyte layer inside a ring-shaped fastener, the outer peripheral structure of the electrolyte layer matching the inner peripheral structure of the ring-shaped fastener, the ring-shaped fastener being used to support the electrolyte layer and prevent the electrolyte layer from deforming; (3) spraying an anode material on at least part of the surface of the electrolyte layer to form an anode layer; (4) spraying a metal support material on the side of the anode layer away from the electrolyte layer to form a metal support layer; (5) spraying a cathode material on at least part of the surface of the electrolyte layer away from the anode layer to form a cathode layer, so as to form a metal support SOFC.

2. The method of claim 1, wherein, The material of the ring-shaped fastener is the same as that of the metal support layer; And / or, the material of the metal support layer comprises at least one of Fe-based alloy, Ni-based alloy and Cr-based alloy.

3. The method of claim 1, wherein, Step (3) further comprises, before spraying the anode material on at least part of the surface of the electrolyte layer, setting a spraying protection tool on the ring-shaped fastener to ensure that the anode layer is formed only on the surface of the electrolyte layer; And / or, step (5) further comprises, before spraying the cathode material on at least part of the surface of the electrolyte layer away from the anode layer, polishing the side of the electrolyte layer away from the anode layer to a thickness of 10-50 microns of the electrolyte layer; And / or, step (5) further comprises, before spraying the cathode material on at least part of the surface of the electrolyte layer away from the anode layer, setting a spraying protection tool on the ring-shaped fastener to ensure that the cathode layer is formed only on the surface of the electrolyte layer.

4. The method of claim 1, wherein, In step (1), the sintering temperature is 1400-1500℃; And / or, in step (1), the thickness of the electrolyte layer is 100-1000 microns.

5. The method of claim 4, wherein, In step (1), the thickness of the electrolyte layer is 250-500 microns.

6. The method of claim 1, wherein, In step (2), the thickness of the electrolyte layer is equal to the thickness of the ring-shaped fastener, and the inner peripheral circumference of the ring-shaped fastener is greater than the outer peripheral circumference of the electrolyte layer; And / or, in step (2), during the process of setting the electrolyte layer inside the ring-shaped fastener, the gap between the electrolyte layer and the ring-shaped fastener is brazed to achieve a fastening connection between the electrolyte layer and the ring-shaped fastener.

7. The method of claim 6, wherein, In step (2), the difference between the inner peripheral circumference of the ring-shaped fastener and the outer peripheral circumference of the electrolyte layer ranges from 3.14 to 6.28 mm.

8. The method of claim 1, wherein, The material of the electrolyte layer comprises at least one of YSZ, ScSZ, GDC, LSGM, BZCYYb and BZCY; And / or, in step (3), the material of the anode layer comprises at least one of Ni / YSZ and Ni / GDC; And / or, in step (3), the method of spraying the anode material on at least part of the surface of the electrolyte layer comprises at least one of atmospheric plasma spraying, high-velocity oxy-fuel spraying and cold spraying; and / or, in step (4), the method of spraying the support material on the side of the anode layer away from the electrolyte layer comprises at least one of atmospheric plasma spraying, high velocity oxy-fuel spraying, and cold spraying.

9. The method according to any one of claims 1-8, characterized in that, In step (5), the material of the cathode layer comprises at least one of LSM, LSCF, LSC; and / or, in step (5), the method of spraying the cathode material on the electrolyte layer away from at least part of the surface of the anode layer comprises at least one of atmospheric plasma spraying, high velocity oxy-fuel spraying, and cold spraying.

10. The method according to any one of claims 1-8, characterized in that, The density of the electrolyte layer in the metal-supported SOFC is not less than 99%.

11. A metal supported SOFC, characterized in that, The metal-supported SOFC is prepared by the method of any one of claims 1-10.

12. A fuel cell characterized by comprising: The metal-supported SOFC is prepared by the method of any one of claims 1-10.

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