JP2016115506A - Metal support SOFC - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce anxiety about the occurrence of exfoliation at a position between an anode layer and an electrolyte layer.SOLUTION: A metal support SOFC has a laminated structure in which an anode layer 18 containing Ni and an electrolyte layer 16 are sequentially laminated on a support body 14 of a porous metal containing Fe and Cr. A part of Fe and Cr contained in the support body 14 is diffused in the anode layer 18 and a part of Ni contained in the anode layer 18 is diffused in the support body 14. The amount of Fe and Cr diffused in the anode layer 18 is reduced as it goes farther from the composition surface between the support body 14 and the anode layer 18. The amount of Ni diffused in the support body is similarly reduced as it goes farther from the composition surface of the support body 14 and the anode layer 18.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a metal support SOFC (Solid Oxide Fuel Cell), in particular, a porous metal support containing Fe (iron) and Cr (chromium), an anode layer containing Ni (nickel), an electrolyte layer, The present invention relates to a metal support SOFC having a structure in which are sequentially stacked.

  In the metal support SOFC, a power generation cell in which an anode layer, an electrolyte layer, and a cathode layer are laminated is formed on a porous support made of a ferritic stainless steel. At this time, the support is in contact with the anode layer forming the power generation cell. The support also contains Fe and Cr, the anode layer contains Ni and stabilized zirconia, and the electrolyte layer contains stabilized zirconia.

Special table 2012-508320

  However, when the power generation cell and the support are fired at 1100 ° C. or higher in order to densify the electrolyte, Fe and Cr diffuse from the support to the anode layer or Ni diffuses from the anode layer to the support, and the support or anode layer At least a part of each of these components is transformed into an alloy made of FeCrNi.

  The thermal expansion coefficient of the alloy composed of FeCrNi formed on the anode layer or the support is larger than that of the stabilized zirconia contained in the anode layer. This may cause separation between the stabilized zirconia contained in the anode layer and the alloy composed of FeCrNi formed on the anode layer or the support.

  Therefore, a main object of the present invention is to provide a metal support SOFC that can alleviate the concern that peeling occurs at a position between an anode layer and an electrolyte layer.

  A metal support SOFC according to the present invention is a metal support SOFC having a laminated structure in which an anode layer containing Ni and an electrolyte layer are sequentially laminated on a porous metal support containing Fe and Cr. The amount of Fe and Cr in the layer decreases as it goes from the support to the electrolyte layer.

  Preferably, the support has one main surface and the other main surface facing in opposite directions, the anode layer is bonded to the one main surface, and the amount of Ni in the support is from one main surface to the other main surface. Decreases as

  More preferably, all Ni diffused in the support is alloyed.

  Preferably, the anode layer is a layer co-sintered with the electrolyte layer.

  Preferably, in the laminated structure, a sintered body including an anode layer, an electrolyte layer, and a sacrificial layer is manufactured by co-sintering, and a bonded body is manufactured by bonding a support to the sintered body. Is removed.

  More preferably, the sintered body is produced at a temperature of 1100 ° C. or higher, and the joined body is produced at a temperature of 1050 ° C. or lower.

  When part of Fe and Cr contained in the support diffuses into the anode layer containing Ni, an alloy made of FeCrNi is formed in the anode layer. However, the amount of Fe and Cr in the anode layer decreases as it goes from the support to the electrolyte layer. As a result, the thermal expansion coefficient of the anode layer approaches the thermal expansion coefficient of the electrolyte layer as it goes from the support to the electrolyte layer. As a result, it is possible to reduce the concern that peeling occurs at a position between the anode layer and the electrolyte layer.

  The above object, other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

It is a side view which shows an example of the structure of metal support SOFC. It is a side view which shows an example of the structure of the laminated body produced in the process of manufacturing metal support SOFC. It is a side view which shows an example of the structure of the joined body produced in the process of manufacturing metal support SOFC. FIG. 4 is an illustrative view showing one example of a state where a sacrificial layer is removed from the joined body shown in FIG. 3. It is a side view which shows an example of the structure of each metal support SOFC of Examples 1-6 and Comparative Examples 1-2. It is a side view which shows an example of the structure of the metal support SOFC of the comparative example 5. It is a side view which shows an example of the structure of the laminated body produced in the process of manufacturing the metal support SOFC of the comparative example 6. It is a side view which shows an example of the structure of the metal support SOFC of the comparative example 6. It is an illustration figure which shows an example of the structure of the fuel cell unit carrying the metal support SOFC.

With reference to FIG. 1, the metal support SOFC includes a power generation cell 12 including an electrolyte layer 16, an anode layer 18, and a cathode layer 20, and a support 14 that supports the power generation cell 12. In the power generation cell 12, the electrolyte layer 16 is sandwiched between the anode layer 18 and the cathode layer 20. That is, the anode layer 18 is formed on the lower surface of the electrolyte layer 16, and the cathode layer 20 is formed on the upper surface of the electrolyte layer 16. In an intermediate stage for producing such a power generation cell 12, a sacrificial layer 22 shown in FIG. 2 is formed on the upper surface of the electrolyte layer 16.
[Examples 1-6 and Comparative Examples 1-2]

In each of Examples 1 to 6 and Comparative Examples 1 and 2, the electrolyte layer 16, the anode layer 18, the cathode layer 20, the sacrificial layer 22, and the support 14 are configured as follows.
(Electrolyte layer)

  The electrolyte layer 16 is made of a solid oxide having high ionic conductivity, and is formed of, for example, stabilized zirconia or partially stabilized zirconia. Specific examples of the stabilized zirconia include 10 mol% yttria stabilized zirconia (10YSZ), 11 mol% scandia stabilized zirconia (11ScSZ), and the like. Specific examples of the partially stabilized zirconia include 3 mol% yttria partially stabilized zirconia (3YSZ).

In addition, the electrolyte layer 16 is formed of a ceria-based oxide doped with Sm, Gd, or the like, or La0.8Sr0.2Ga0 in which a part of La and a part of Ga are substituted with Sr and Mg, respectively, using LaGaO3 as a base material. Alternatively, the electrolyte layer 16 may be formed of a perovskite oxide such as .8Mg0.2O (3-δ). However, in Examples 1 to 6 and Comparative Examples 1 and 2, 11 mol% scandia-stabilized zirconia (11ScSZ) was employed.
(Anode layer)

In the anode layer 18, oxygen ions react with the fuel gas, thereby releasing electrons. The anode layer 18 is a porous layer having a high electron conductivity, and is preferably a layer that hardly reacts with the electrolyte layer 16 or the like at a high temperature. The anode layer 18 is made of yttria-stabilized zirconia (YSZ) / nickel metal porous cermet, scandia-stabilized zirconia (ScSZ) / nickel metal porous cermet, or the like. However, in Examples 1 to 6 and Comparative Examples 1 and 2, a scandia-stabilized zirconia (ScSZ) / nickel metal porous cermet was employed.
(Cathode layer)

In the cathode layer 20, oxygen ions are formed by oxygen taking in electrons. The cathode layer 20 is also a porous layer having a high electron conductivity, and is preferably a layer that hardly causes a solid-solid reaction with the electrolyte layer 16 or the like at a high temperature. The cathode layer 20 is made of LaMnO 3 oxide, LaCoO 3 oxide, or the like, such as La0.8Sr0.2MnO3 (common name: LSM), La0.8Sr0.2Co0.2Fe0.8O3 (common name: LSCF), or the like. It is done. However, in Examples 1-6 and Comparative Examples 1-2, La0.8Sr0.2MnO3 was employed.
(Sacrificial layer)

As a material for the sacrificial layer 22, a material having high adhesiveness to the electrolyte layer 16 and having a property of being easily removed from the electrolyte layer 16 is selected. For example, the sacrificial layer 22 is formed of porous stabilized zirconia, porous partially stabilized zirconia, or the like having a thermal expansion coefficient equivalent to that of the electrolyte layer 16. However, in Examples 1 to 6 and Comparative Examples 1 and 2, porous 11 mol% scandia-stabilized zirconia (11ScSZ) was employed.
(Support)

As the material of the support 14, ferritic stainless steel (containing Fe and Cr) having a thermal expansion coefficient close to that of the electrolyte layer 16 is used. In Examples 1 to 6 and Comparative Examples 1 and 2, a porous plate made of SUS430 and having a thickness of 500 μm was used.
[Production method]

  Subsequently, a method for producing a metal support SOFC in each of Examples 1 to 6 and Comparative Examples 1 and 2 will be described below.

  First, a polyvinyl butyral binder and a mixture of ethanol and toluene as an organic solvent (weight ratio is 1: 4) are mixed into the raw material powders of the electrolyte layer 16, the anode layer 18, and the sacrificial layer 22. Next, green sheets of each of the electrolyte layer 16, the anode layer 18, and the sacrificial layer 22 are produced by a doctor blade method. The ratio of pores finally formed in the anode layer 18 and the sacrificial layer 22 is adjusted by the ratio of the binder and the raw material powder.

Subsequently, the green sheets were laminated so that the anode layer 18 had a thickness of 50 μm, the electrolyte layer 16 had a thickness of 50 μm, and the sacrificial layer 22 had a thickness of 300 μm, a pressure of 1000 kgf / cm ² and a temperature of 80 ° C. And cold isostatic pressing for 2 minutes. These operations are performed corresponding to each of Examples 1 to 6 and Comparative Examples 1 and 2, and thereby, eight laminated bodies in which the anode layer 18, the electrolyte layer 16, and the sacrificial layer 22 are pressure-bonded to each other are manufactured. . Each produced laminate has a structure shown in FIG.

All of the produced eight laminated bodies are degreased in the temperature range of 300 to 500 ° C. in the atmosphere. The eight laminates that have undergone the degreasing treatment are then co-sintered at the firing temperatures of Examples 1 to 6 and Comparative Examples 1 and 2 in the air. According to Table 1, the firing temperature is set to 1200 ° C. for Examples 1-3, 6 and Comparative Examples 1-2, 1100 ° C. for Example 4, and 1300 ° C. for Example 5. .

  When eight sintered bodies corresponding to Examples 1 to 6 and Comparative Examples 1 and 2 are produced in this manner, the lower surface of the anode layer 18 constituting each sintered body is polished for planarization. The polished eight sintered bodies were then placed in an H2 / Ar atmosphere containing 5% H2, with the lower surface of the anode layer 18 in contact with the upper surface of the support 14, and Examples 1-6 And it heat-processes on the conditions of Comparative Examples 1-2.

  According to Table 1, the sintered body of Example 1 was placed in an H2 / Ar atmosphere at 900 ° C. for 10 minutes, and the sintered bodies of Examples 2, 4 and 5 were placed in an H2 / Ar atmosphere at 1000 ° C. for 10 minutes. The sintered body of Example 3 was placed in an H2 / Ar atmosphere at 1050 ° C. for 10 minutes, the sintered body of Example 6 was placed in an H2 / Ar atmosphere at 1050 ° C. for 60 minutes, and the sintered body of Comparative Example 1 was sintered. The body is placed in an H2 / Ar atmosphere at 1100 ° C. for 10 minutes, and the sintered body of Comparative Example 2 is placed in an H2 / Ar atmosphere at 850 ° C. for 10 minutes.

  As a result, eight joined bodies respectively corresponding to Examples 1 to 6 and Comparative Examples 1 and 2 are produced. Each manufactured joined body has a structure shown in FIG. Referring to FIG. 3, a part of Fe and Cr contained in support 14 diffuses into anode layer 18, and a part of Ni contained in anode layer 18 diffuses into support 14. As a result, an FeCrNi alloy having a large thermal expansion coefficient is formed in the vicinity of the interface between the support 14 and the anode layer 18.

  Further, the amount of Fe and Cr diffused in the anode layer 18 decreases as it goes from the lower surface of the anode layer 18 toward the upper surface, and the amount of Ni diffused into the support member 14 decreases as it goes from the upper surface of the support member 14 toward the lower surface. Furthermore, all the Ni diffused in the support 14 is alloyed.

The sacrificial layer 22 is removed from each joined body by a polishing process using a zirconia slurry abrasive. As a result, the upper surface of the electrolyte layer 16 is exposed (see FIG. 4). On the exposed upper surface, a cathode layer 20 having a thickness of about 50 μm is formed by screen printing. Thus, eight metal support SOFCs corresponding to Examples 1 to 6 and Comparative Examples 1 and 2 are completed. Each metal support SOFC has a structure shown in FIG.
[Evaluation]

  The appearance of each completed metal support SOFC was observed as a sample, and the presence or absence of peeling was confirmed. For the sample in which the power density can be evaluated, the measurement temperature is 850 ° C., 40% humidified hydrogen is supplied to the anode layer 18 side, and air is supplied to the cathode layer 20 side. The power density at 7V was evaluated.

  After that, each sample was kept energized for 24 hours while being fixed at a current value indicating 0.7 V (= voltage V1) in the initial characteristics, and whether or not the voltage V2 after 24 hours is lower than the voltage V1 by 10% or more. Durability was evaluated.

Moreover, the composition analysis of the cross section was performed about the sample of the state which cannot evaluate power density. Specifically, the composition of Fe, Cr and Ni was analyzed.
[result]

Power generation could be confirmed for the six samples corresponding to Examples 1 to 6, respectively. Specifically, the output density of the sample of Example 1 is 0.4 W / cm ² , the output density of the sample of Example 2 is 0.38 W / cm ^2, and the output density of the sample of Example 3 is 0.2 W / cm ² , the output density of the sample of Example 4 is 0.36 W / cm ² , the output density of the sample of Example 5 is 0.25 W / cm ^2, and the sample of Example 6 The power density was 0.18 W / cm ² . In these samples, there was no problem with respect to peeling or durability of the electrolyte layer 16. As can be seen from a comparison of Example 6 with Examples 1 to 5, if the temperature is 1050 ° C., good output characteristics can be obtained even if the sintered body is placed in an H2 / Ar atmosphere for a long time.

On the other hand, in the sample of Comparative Example 1, peeling occurred at a position between the anode layer 18 and the electrolyte layer 16, and the power generation characteristics could not be evaluated. When the composition analysis of the cross section of the peeled portion was performed, the diffusion of Fe and Cr was observed throughout the anode layer 18, and it was confirmed that the diffusion was proceeding more than in Examples 1-6. The formation of an alloy of FeCrNi having a large thermal expansion coefficient is considered to be a cause of peeling. Further, in the sample of Comparative Example 2, since the temperature was too low, the sintered body could not be joined to the support 14 and the output density could not be evaluated.
[Comparative Examples 3 to 5]

  Subsequently, three metal support SOFCs corresponding to Comparative Examples 3 to 5 will be described. The metal support SOFC of Comparative Example 3 or 4 has the same structure as each of Comparative Examples 1 and 2. On the other hand, in the metal support SOFC of Comparative Example 5, the diffusion prevention layer 24 is added between the support 14 and the anode layer 18 (see FIG. 6).

As a raw material for the diffusion preventing layer 24, Gd-doped CeO2 (GDC) having a thermal expansion coefficient relatively close to the thermal expansion coefficient of the electrolyte layer 16 and exhibiting electronic conductivity at a high temperature was employed. Further, in Comparative Examples 3 to 5, the production method of the support 14 was different from that of each of Comparative Examples 1 and 2, and SUS430 atomized powder was adopted as the raw material of the support 14.
[Production method]

  First, a mixture of a revinyl butyral binder and ethanol and toluene as an organic solvent (weight ratio is 1: 4) is added to each of the support 14, the electrolyte layer 16, the anode layer 18, and the diffusion prevention layer 24. Mix in raw powder. Next, green sheets of the support 14, the electrolyte layer 16, the anode layer 18, and the diffusion prevention layer 24 are prepared by a doctor blade method. The ratio of the pores finally formed in the support 14, the anode layer 18 and the diffusion preventing layer 24 is adjusted by the ratio of the binder and the raw material powder.

Subsequently, in each of Comparative Examples 3 and 4, the green sheets are laminated so that the thickness of the support 14 is 500 μm, the thickness of the anode layer 18 is 50 μm, and the thickness of the electrolyte layer 16 is 50 μm. In Comparative Example 5, the thickness of the support 14 is 500 μm, the thickness of the diffusion prevention layer 24 is 10 μm, the thickness of the anode layer 18 is 50 μm, and the thickness of the electrolyte layer 16 is 50 μm. Laminate sheets. The laminate is subjected to cold isostatic pressing for 2 minutes at a pressure of 1000 kgf / cm ² and a temperature of 80 ° C. as described above.

All the produced three laminated bodies are degreased in the temperature range of 300 to 500 ° C. in the atmosphere. Thereafter, the laminate subjected to the degreasing treatment is placed in an H2 / Ar atmosphere containing 5% of H2, and held at the firing temperature of each of Comparative Examples 3 to 10 for 10 hours. According to Table 2, the laminated body of the comparative example 3 is hold | maintained at 1000 degreeC for 10 hours, and each laminated body of the comparative examples 4 and 5 is hold | maintained at 1100 degreeC for 10 hours.

When three sintered bodies corresponding to Comparative Examples 3 to 5 are thus prepared, the cathode layer having a thickness of about 50 μm is then formed on the upper surface of the electrolyte layer 16 (the surface opposite to the anode layer 18 side). 20 is formed by screen printing. Thus, three metal support SOFCs corresponding to Comparative Examples 3 to 5 are completed.
[Evaluation]

  The appearance of each completed metal support cell was observed, and the presence or absence of peeling was confirmed. Further, for a sample in a state where the output density can be evaluated, the measurement temperature is set to 850 ° C., 40% humidified hydrogen is supplied to the anode layer 18 side, and air is supplied to the cathode layer 20 side to supply 0.7V. The power density at was evaluated.

  After that, each sample was continuously energized for 24 hours while being fixed at a current density of 0.7 V (= voltage V1) in the initial characteristics, and durability was determined depending on whether the voltage V2 after 24 hours was lower than the voltage V1 by 10% or more. Sex was evaluated.

Moreover, the composition analysis of the cross section was performed about the sample of the state which cannot evaluate power density. Specifically, the composition of Fe, Cr and Ni was analyzed.
[result]

  In the sample of Comparative Example 3, since the electrolyte layer 16 was not sufficiently sintered and was not densified, the atmosphere on the anode layer 18 side and the atmosphere on the cathode layer 20 side could not be separated during power generation evaluation. Voltage could not be obtained.

  For the sample of Comparative Example 4, peeling occurred at a position between the electrolyte layer 16 and the anode layer 18, and the power generation characteristics could not be evaluated. When the composition analysis of the cross section of the peeled portion was performed, diffusion of Fe and Cr was observed throughout the anode layer 18. The formation of an FeCrNi alloy having a large thermal expansion coefficient is considered to be a cause of peeling.

As for the sample of Comparative Example 5, it can be seen that the diffusion preventing layer 24 functioned effectively and the diffusion could be suppressed. However, since the conductivity of the diffusion preventing layer 24 is low, the power generation characteristics are the lowest among the samples that can generate power.
[Comparative Example 6]

Subsequently, a metal support SOFC corresponding to Comparative Example 6 will be described. The metal support SOFC of Comparative Example 6 has the same structure as that of Comparative Example 3 or 4. However, in forming the anode layer 18, first, the anode skeleton layer 18f is formed (see FIG. 7). The material of the anode skeleton layer 18f is the same as the material of the sacrificial layer 22, and a porous layer for impregnating the anode catalyst (Ni (O)) is used as the anode skeleton layer 18f.
[Production method]

  A polyvinyl butyral binder and a mixture of ethanol and toluene as an organic solvent (mixing ratio by weight is 1: 4) are mixed into the raw material powder of each of the support 14, the electrolyte layer 16, and the anode skeleton layer 18f. Next, green sheets of the support 14, the electrolyte layer 16, and the anode skeleton layer 18 f are prepared by a doctor blade method. The ratio of the pores finally formed in the support 14 and the anode skeleton layer 18f is adjusted by the ratio of the binder and the raw material powder.

Subsequently, the green sheets are laminated so that the support 14 has a thickness of 500 μm, the anode skeleton layer 18 f has a thickness of 50 μm, and the electrolyte layer 16 has a thickness of 50 μm. The laminate is subjected to cold isostatic pressing for 2 minutes at a pressure of 1000 kgf / cm ² and a temperature of 80 ° C. as described above.

The produced laminate is degreased in the temperature range of 300 to 500 ° C. in the air. The degreased laminate is then placed in an H2 / Ar atmosphere containing 5% H2, and held at 1100 ° C. for 10 hours (see Table 3).

  When the sintered body is thus produced, NiO is then impregnated using an aqueous nickel nitrate solution. Specifically, the sintered body is immersed in an aqueous nickel nitrate solution and boiled to deposit nickel nitrate inside the porous body. The sintered body (sample) impregnated with NiO is then placed in the atmosphere and fired at 550 ° C.

Next, the cathode layer 20 having a thickness of about 50 μm is formed on the upper surface of the electrolyte layer 16 (the surface opposite to the anode layer 18 side) by screen printing. Thereby, the metal support SOFC of Comparative Example 6 is completed (see FIG. 8).
[Evaluation]

  The appearance of the completed metal support cell was observed as a sample, and the presence or absence of peeling was confirmed. Further, for a sample in a state where the output density can be evaluated, the measurement temperature is set to 850 ° C., 40% humidified hydrogen is supplied to the anode layer 18 side, and air is supplied to the cathode layer 20 side to supply 0.7V. The power density at was evaluated.

After that, each sample was continuously energized for 24 hours while being fixed at a current density of 0.7 V (= voltage V1) in the initial characteristics, and durability was determined depending on whether the voltage V2 after 24 hours was lower than the voltage V1 by 10% or more. Sex was evaluated.
[result]

In the sample of Comparative Example 6, power generation was possible, but the durability for 24 hours was NG. This is presumably because Ni sintered at a low temperature aggregated under power generation conditions of 850 ° C. From these results, as in Examples 1 to 4, the degreased laminate including the anode layer 18, the electrolyte layer 16, and the sacrificial layer 22 was fired at a temperature of 1100 ° C to 1200 ° C, and the sintered body was 900 ° C. Joining the support 14 in a H2 / Ar atmosphere at 1050 ° C. seems to be effective for producing a metal support SOFC.
[Configuration of fuel cell unit]

  The metal support SOFC corresponding to each of Examples 1 to 4 is housed in a sealed container 30 made of quartz glass in the manner shown in FIG. 9, thereby completing the fuel cell unit.

  Referring to FIG. 9, a cylindrical body 32 and alumina tubes 36 and 38 are disposed inside the sealed container 30. A pyrex glass 34 is provided at the upper end of the cylindrical body 32. The metal support SOFC is placed on the upper end of the cylindrical body 32 in an upside down posture. The electrolyte layer 16 forming the metal support SOFC is in contact with the cylindrical body 32 through the Pyrex glass 34.

  Fuel gas (hydrogen) is supplied to the periphery of the support 14 via the alumina tube 36, and air is supplied to the periphery of the cathode layer 20 via the alumina tube 38. Electric power generated based on the supplied fuel gas and air is taken out by current collectors (Pt paste or PT wire) 40 and 42.

  As can be seen from the above description, the metal support SOFC corresponding to each of Examples 1 to 4 includes a porous metal support 14 containing Fe and Cr, an anode layer 18 containing Ni, an electrolyte layer 16, and the like. Have a stacked structure in which are sequentially stacked. Here, a part of Fe and Cr contained in the support 14 diffuses into the anode layer 18, while a part of Ni contained in the anode layer 18 diffuses into the support 14, whereby the support 14 and the anode layer are diffused. An FeCrNi alloy is formed in the vicinity of the interface with 18.

  Further, the amount of Fe and Cr diffused into the anode layer 18 decreases as it goes from the lower surface to the upper surface of the anode layer 18, and the amount of Ni diffused into the support member 14 decreases as it goes from the upper surface to the lower surface of the support member 14. Furthermore, all the Ni diffused in the support 14 is alloyed.

  The thermal expansion coefficient of Ni contained in the anode layer 18 is larger than that of the stabilized zirconia contained in the electrolyte layer 16, and the thermal expansion coefficient of the FrCrNi alloy is larger than that of Ni. The amount of Fe and Cr diffused in the anode decreases as it goes from the lower surface to the upper surface of the anode layer 18.

  Therefore, the thermal expansion coefficient of the anode layer 18 approaches the thermal expansion coefficient of the electrolyte layer 16 as it goes from the support 14 to the electrolyte layer 16. As a result, it is possible to reduce the concern that peeling occurs at a position between the anode layer 18 and the electrolyte layer 16. Moreover, the adhesion between the anode layer 18 and the support 14 is improved by forming the FeCrNi alloy layer.

  Further, the amount of Ni diffused into the support 14 decreases as it goes from the upper surface to the lower surface of the support 14. As a result, the thermal expansion coefficient does not change abruptly in the support 14, and the concern that the support 14 is peeled off is reduced.

  Further, since Ni diffused in the support 14 is all alloyed, Ni is not alloyed in the support 14 during high-temperature power generation of the completed metal support SOFC, and the Ni content is locally high. No FeCrNi alloy is formed. As a result, it is possible to reduce the concern that the support 14 is destroyed in the heat cycle due to the difference in thermal expansion coefficient.

  Moreover, the above-mentioned laminated structure is produced by co-sintering a sintered body composed of the anode layer 18, the electrolyte layer 16, and the sacrificial layer 22, and joining the support 14 to the sintered body to produce a joined body. The sacrificial layer 22 is removed from the joined body. Here, the sintered body is manufactured at a temperature of 1100 ° C. or higher (= high temperature), and the bonded body is manufactured at a temperature of 1050 ° C. or lower (= low temperature).

  By co-sintering at a high temperature, the electrolyte layer 16 can be densified. Further, the Ni (O) particles in the anode layer 18 are appropriately aggregated, and aggregation during power generation can be suppressed. Thus, the characteristics of the sintered body are improved. Further, by joining the support 14 to the sintered body at a low temperature, interdiffusion of Fe, Cr, Ni is suppressed to a minimum, and the amount of FeCrNi alloy is maximized at the interface between the support 14 and the anode layer 18. Become. The sacrificial layer 22 contributes to improved handling.

DESCRIPTION OF SYMBOLS 12 ... Power generation cell 14 ... Support body 16 ... Electrolyte layer 18 ... Anode layer 20 ... Cathode layer 22 ... Sacrificial layer 24 ... Diffusion prevention layer

Claims (6)

A metal support SOFC having a laminated structure in which an anode layer containing Ni and an electrolyte layer are sequentially laminated on a porous metal support containing Fe and Cr,
A metal support SOFC in which the amount of Fe and Cr in the anode layer decreases from the support toward the electrolyte layer. The support has one main surface and the other main surface facing in opposite directions;
The anode layer is bonded to the one main surface,
2. The metal support SOFC according to claim 1, wherein the amount of Ni in the support decreases from the one main surface toward the other main surface.   The metal support SOFC according to claim 2, wherein the Ni diffused in the support is all alloyed.   4. The metal support SOFC according to claim 1, wherein the anode layer is a layer co-sintered with the electrolyte layer. 5.   In the laminated structure, a sintered body including the anode layer, the electrolyte layer, and a sacrificial layer is produced by co-sintering, and the joined body is produced by joining the support to the sintered body. 5. The metal support SOFC according to claim 1, wherein the sacrificial layer is removed from the metal support SOFC.   The metal support SOFC according to claim 5, wherein the sintered body is manufactured at a temperature of 1100 ° C. or higher, and the joined body is manufactured at a temperature of 1050 ° C. or lower.

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