JP2013201038A - Metal support type solid oxide fuel battery cell, and solid oxide fuel battery using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a metal support type solid oxide fuel battery cell which is excellent in cell strength, has rigidity against torsion and deflection, and can keep the flatness, and a solid oxide fuel battery which hardly causes breakage of an electrolyte or an electrode when the cells are stacked.SOLUTION: The metal support type solid oxide fuel battery cell has, on a support (A) that is formed of a metal partition and has a honeycomb structure provided with a plurality of through-holes, in which the number of the through-holes is in a range of 25-2000/inchand a thickness (t) is 0.01-0.2 cm, a fuel electrode (B), a solid electrolyte (C) and an air electrode (D) arranged in the order of (B), (C) and (D).

Description

  The present invention relates to a metal-supported solid oxide fuel cell using a metal porous substrate having a honeycomb structure including a plurality of through-holes and having a honeycomb structure as a support, and a solid oxidation using the cell. The present invention relates to a physical fuel cell.

  A solid oxide fuel cell (SOFC) is composed of an electrolyte membrane made of an oxygen ion conductive solid oxide, and a fuel electrode layer and an air electrode layer that are arranged to face each other with the electrolyte membrane interposed therebetween. DC cell based on electrochemical reaction by supplying fuel gas such as hydrogen to the fuel electrode side and supplying oxidizing gas such as air to the air electrode side. Can be obtained.

  In recent years, metal-supported cells, which are superior in mechanical strength, rapid startability, redox resistance, and the like, have been actively developed compared to conventional electrolyte-supported cells and electrode-supported cells. In the metal-supported cell, a three-layer film is formed on a metal support having a three-dimensional porous structure or a honeycomb structure. For example, Japanese Patent Laid-Open No. 11-162483 (Patent Document 1) discloses a metal-supported cell structure in which a mixed conductive thin protective film containing NiO, a solid electrolyte, and a cathode electrode are formed on a porous metal substrate. Proposed. Japanese Patent Laying-Open No. 2005-322452 (Patent Document 2) describes a honeycomb structure substrate made of a metal foil that has excellent cell strength and is light in weight and can reduce the capacity and weight when the cells are integrated (stacked). A cell in which a single cell is formed in each through-hole is disclosed. Further, JP 2010-218759 A (Patent Document 3) describes the surface roughness of the interface between the electrolyte layer and the fuel electrode layer and the interface between the electrolyte layer and the air electrode layer in order to obtain a gastight electrolyte membrane. A technique for specifying the surface roughness is disclosed.

Japanese Patent Laid-Open No. 11-162483 JP-A-2005-322452 JP 2010-218759 A

  However, the metal-supported cell described in the above-mentioned Patent Document 1 has a problem that cracking occurs in the solid electrolyte when it is exposed to a nitrogen atmosphere and the temperature is raised to 800 ° C. and then the cooling cycle to lower to room temperature is repeated 20 times. There is a problem in durability. In addition, the cell fabrication in which each through-hole of the honeycomb structure made of metal foil of Patent Document 2 is filled with a part of cell constituent elements is complicated, and it is difficult to obtain a uniform cell. The inventors of the present application have found that there is a problem that the cell constituent elements are peeled off from the surface of the through-hole of the honeycomb structure made of the present invention.

  Furthermore, in the high-speed flame spraying method of Patent Document 3, the fuel electrode layer formed by spraying a metal oxide powder for a fuel electrode having a specific particle size on a metal support is not necessarily compared with the adhesion to the electrolyte layer. Adhesion with the metal support is not sufficient, and if the metal support cell is exposed to a thermal cycle between room temperature and power generation performance evaluation temperature, a part of the metal support and the fuel electrode layer may be separated. It has been found by the inventors' examination.

  In particular, in recent years, in solid oxide fuel cells, it is required to reduce the size of the fuel cell power generation unit while ensuring the amount of power generation per volume. In addition to the above problems, metal-supported cells repeatedly generate power. It has been found that the flatness of the metal support also affects the flatness of the cells because the metal support tends to be distorted and bent and the flatness is remarkably deteriorated.

  In addition, when a metal-supported cell is stacked to form a solid oxide fuel cell, a load is applied to the cell, and a load may be forcibly applied from the top of the stack to improve current collection. It was also found that there was a problem that the electrolyte and electrodes on the body were damaged.

  The present invention has been made in view of the above problems in the conventional solid oxide fuel cell, and the object of the present invention is to have excellent cell strength and rigidity against distortion and deflection, and to maintain flatness. It is an object of the present invention to provide a cell for a metal-supported solid oxide fuel cell that can be manufactured, and a solid oxide fuel cell in which damage to an electrolyte or an electrode hardly occurs when such cells are stacked.

The inventors of the present invention have made extensive studies to solve the above problems. As a result, as a result of examining the structure and the like of the metal support substrate for the metal-supported solid oxide fuel cell, it is composed of metal partition walls, and has a plurality of through holes, and the number of through holes is 25 to 2000 / inch ^2. In the range described above, the inventors have found that the above object can be achieved by using a support having a honeycomb structure having a thickness (t) of 0.01 to 0.2 cm, and the present invention has been completed.

That is, the metal-supported solid oxide fuel cell according to the present invention includes a metal partition wall and includes a plurality of through holes, and the thickness (t) is within a range of 25 to 2000 / inch ^2. ) On a support (A) having a honeycomb structure of 0.01 to 0.2 cm, a fuel electrode (B), a solid electrolyte (C) and an air electrode (D) are (B), (C), They are arranged in the order of (D).

The cell for a metal-supported solid oxide fuel cell according to the present invention is composed of a metal partition, has a plurality of through holes, and has a thickness (t in the range of 25 to 2000 / inch ^2. ) Is 0.01 to 0.2 cm, and the ratio (s / t ² ) between the plane area (s) and the square of the thickness (t) of the support (A) is 10,000 / 1 to 400. On the support (A) in the range of 1,000,000 / 1, the fuel electrode (B), the solid electrolyte (C) and the air electrode (D) are in the order (B), (C), (D). It is characterized by being arranged.

Furthermore, the metal-supported solid oxide fuel cell according to the present invention includes a metal partition wall and includes a plurality of through holes, and the thickness (t) is within a range of 25 to 1000 / inch ^2. ) Is 0.01 to 0.2 cm, and the ratio (s / t ² ) between the plane area (s) and the square of the thickness (t) of the support (A) is 10,000 / 1 to 400. The fuel electrode (B), the solid electrolyte (C), and the air electrode (D) on the support (A) having a honeycomb structure having a plane area (s) of 50 to 1000 cm ² in a range of 1,000,000 / 1. ) Are arranged in the order of (B), (C), (D).

  The present invention further provides a solid oxide fuel cell characterized by using the above-mentioned metal-supported solid oxide fuel cell, and has excellent cell strength and flatness. Even when a load is applied, since the cell partition wall is folded and acts as a buffer while supporting a certain load with the honeycomb structure metal support, the electrolyte and the electrode are not damaged, and the reliability is high.

  According to the present invention, the cell strength is excellent and the cell flatness is excellent even when the cooling cycle is repeated, the cell flatness is excellent, the separation of the three-layer membrane cell from the honeycomb structure metal support is difficult, and simple. It is possible to provide a metal-supported solid oxide fuel cell that can be produced by the production method, and a solid oxide fuel cell that does not cause damage to the electrolyte or electrode even when such cells are stacked.

It is typical sectional drawing of the cell for metal support type solid oxide fuel cells of the present invention.

A: honeycomb structure metal support, B: fuel electrode, C: solid electrolyte, D: air electrode, E: cell for metal support type solid oxide fuel cell

The cell for a metal-supported solid oxide fuel cell according to the present invention is composed of a metal partition, has a plurality of through holes, the number of through holes is in the range of 25 to 2000 / inch ² , and the thickness (t) is On the support (A) having a honeycomb structure of 0.01 to 0.2 cm, the fuel electrode (B), the solid electrolyte (C), and the air electrode (D) are (B), (C), (D The metal-supported solid oxide fuel cell is arranged in the order of

The material of the support (A) composed of the metal partition walls and having a honeycomb structure having a plurality of through holes is not particularly limited, and is nickel, nickel-based heat-resistant alloy, nickel-chromium alloy, iron-chromium alloy, Examples include austenitic stainless steel SUS304, ferritic stainless steel SUS430, and SUS410. Among these, ferritic stainless steel used as a carrier for an exhaust gas treatment catalyst for automobiles is preferable because of its versatility.

  The shape of the plurality of through-holes forming the honeycomb structure is preferably a combination of two waveforms such as a triangle, a quadrangle, a hexagon or a corrugated shape, or a combination of one waveform and one straight line or curve. Of these, two or more kinds of shapes may be combined.

  The number of through-holes is preferably 100 to 2000, more preferably 150 to 1600 per inch square from the viewpoint of forming a three-layer film cell on the support and manufacturing a honeycomb structure metal support. 200 to 1200 is particularly desirable.

  Further, the thickness of the metal partition wall that partitions the through hole is preferably 10 to 1000 μm from the viewpoint of stable production of the honeycomb structure and cell power generation performance due to pressure loss in the support, and buffering action on the electrolyte and the electrode at the time of stacking, 15-800 micrometers is more desirable, 20-500 micrometers is still more desirable, and 30-400 micrometers is especially desirable.

  The above-mentioned metal partition walls do not have to have the same partition wall thickness, and because the partition wall thickness at a certain interval is thicker than other partition wall thicknesses, the strength of the metal support is increased and the deflection resistance is also improved. This is preferable because it tends to improve. Moreover, since the cylindrical part of the outermost periphery of the support body holds and fixes the partition wall and also serves as a seal part with the three-layer film cell, the thickness is preferably 500 to 3000 μm thicker than the metal partition wall.

  The thickness (height) of the support (A) is preferably 0.01 to 0.2 cm from the viewpoint of the flatness of the support due to the compactness of the fuel cell device depending on the cell capacity and the repetition of the cooling and heating cycle. 0.012 to 0.1 cm is more desirable, 0.015 to 0.05 cm is further desirable, and 0.018 to 0.04 cm is particularly desirable.

  The flatness referred to here is the magnitude of the deviation from the geometrically correct plane of the flat form defined in JIS B0621. With reference to this, the partition wall of the metal support in which the through hole is opened The difference between the highest point and the lowest point of the end face was taken. The measuring method is not particularly limited, and can be measured using a contact or non-contact type three-dimensional measuring instrument. When using a contact type three-dimensional measuring instrument, after fixing the metal support on the surface plate, set a temporary reference point by performing four-point plane measurement using a probe (measurement terminal) on the partition wall end face of the metal support. Then, the origin of the XY axis of this end face is set, the probe is scanned from the origin in the X-axis direction and the Y-axis direction, measured at an arbitrary point, and the value of the highest point and the lowest point on the measured end face Flatness was calculated from the difference between the two.

  The flatness of the partition wall end face of the metal support used in the present invention is preferably 10 μm or less, more preferably 5 μm or less, and particularly preferably 3 μm or less. Further, the flatness of the metal support after repeated cooling and heating cycles is preferably 30 μm or less, more preferably 20 μm or less, and particularly preferably 10 μm or less. The flatness of the three-layer membrane cell on the metal support is preferably 30 μm or less, more preferably 20 μm or less, and particularly preferably 10 μm or less from the viewpoint of interfacial peeling between the cell electrode layer and the support. The smaller the flatness is, the less likely peeling occurs, so the lower limit of flatness is zero.

Further, the size of the support (A) is defined by the size of the three-layer film cell formed on the support (A), and is generally the same as or almost the same as the planar area of the cell. Usually, the planar area of the metal support is 50 to 1000 cm ² , desirably 75 to 900 cm ² , more desirably 90 to 750 cm ² , and particularly desirably 100 to 500 cm ² .

In the present invention, the support (A) is a thin film having a large planar area and a low thickness, and the relationship is the ratio of the planar area (s) to the square of the thickness (t) ( s / t ² ) is desirably in the range of 10,000 / 1 to 400,000 / 1. In general, if the planar area of the metal support is large and the thickness is small, when the heat cycle is repeated, the horse's saddle-like twist, deflection, and warpage are likely to occur due to the thermal stress. However, it is difficult to maintain the flatness of the support, and the rigidity of the support can be maintained by setting the planar area and thickness of the support to the above relationship. The ratio (s / t ² ) between the plane area (s) and the square of the thickness (t) is more preferably in the range of 20,000 / 1 to 350,000 / 1, more preferably 30,000 / 1. It is more desirable to be in the range of ~ 300,000 / 1, and it is particularly desirable to be in the range of 50,000 / 1 to 200,000 / 1.

  Further, the end face shape of the support (A) may be any of a circular shape, an elliptical shape, a rectangular shape, a rectangular shape having R (R), a rounded rectangular shape, or a cylindrical shape having these shapes. In addition, the said support body end surface is a support body surface other than the side surface of a support body outermost periphery cylinder part, and says the surface comprised from a partition surface, a through-hole surface, and an outermost periphery cylinder part surface.

In the present invention, in the thin film-like support having the dimensions specified as described above, a honeycomb having protrusions having a linear or curved height of 1 μm or more such as a needle shape, a rod shape, or a whisker shape formed on the surface of the metal partition wall A structure is desirable. The projections present surface 1 cm ² per average 10 or more on the metal surface of the partition wall, and by a more 1μm height of the protrusions can easily form a three-layered film cells on a support, moreover, thermal cycle By repeating the above, since the adhesion to the support and the electrode layer formed thereon is excellent, stable power generation performance can be exhibited as a fuel cell.

  Alternatively, in the present invention, it is also desirable that the thin film-like support having the dimensions specified as described above has a honeycomb structure in which irregularities are formed on the surface of the metal partition walls. In addition, the unevenness | corrugation said here is the dimple-shaped concave-shaped part and convex-shaped part formed in the position facing the front and back of a metal partition. That is, there are a plurality of concave-shaped portions and a plurality of convex-shaped portions on one surface of the metal partition wall, and the other surface is substantially the same as the portion where the concave-shaped portions and the convex-shaped portions are present on one surface. The position has a convex portion and a concave portion.

By forming these irregularities on the metal partition surface with an average height of 5 or more per 1 cm ² of the surface being 2 μm or more, a three-layer film cell can be easily formed on the support, and also supported by repeated cooling and heating cycles. Since the body and the electrode layer formed thereon are excellent in adhesion, stable power generation performance can be exhibited as a fuel cell.

  Furthermore, in the present invention, it is also desirable that the thin film-like support having the dimensions specified as described above has a honeycomb structure having a porous layer in at least one of the through holes of the support. Even if an electrode is formed on the end face side of the support having a porous layer at one end of the through hole, the dent of the electrode layer at the end of the through hole corresponding to the end face of the through hole is suppressed, and a homogeneous electrode layer is formed. In addition, a three-layer membrane cell can be easily formed on a support, and also has excellent adhesion to the support and the electrode layer formed thereon by repeated cooling and heating cycles. Can be demonstrated.

  The electrolyte layer (C) is not particularly limited as long as it is formed of an oxygen ion conductive metal oxide for a solid electrolyte of a solid oxide fuel cell. Examples of the metal oxide include stabilized zirconia, doped ceria, stabilized bismuth and lanthanum gallate, and these may be used alone or in combination of two or more.

Examples of the stabilized zirconia include oxides of alkaline earth metals such as MgO, CaO, SrO, and BaO, Sc ₂ O ₃ , Y ₂ O ₃ , La ₂ O ₃ , CeO ₂ , Pr ₂ O ₃ , and Nd _2. Oxides of rare earth elements such as O ₃ , Sm ₂ O ₃ , Eu ₂ O ₃ , Gd ₂ O ₃ , Tb ₂ O ₃ , Dy ₂ O ₃ , Ho ₂ O ₃ , Er ₂ O ₃ , Yb ₂ O ₃ , Bi Zirconia in which one or more oxides of other metals such as ₂ O ₃ and In ₂ O ₃ are solid-dissolved as a stabilizer, and further to the stabilized zirconia, Al ₂ O ₃ , TiO ₂ Examples thereof include zirconia to which Ta ₂ O ₅ , Nb ₂ O _{5 and the} like are added as a dispersion strengthening agent. Among the above, zirconia having higher thermal characteristics, mechanical characteristics, chemical characteristics, and oxygen ion conductivity characteristics is stabilized by at least one oxide selected from scandia, yttria, and ceria. Further, partially stabilized zirconia having a tetragonal crystal structure or fully stabilized zirconia having cubic crystal structure is more preferable, 4 to 12 mol% scandia powder, 8 to 11 mol% scandia and 0.5 to 2 mol% ceria, Or zirconia stabilized with 3 to 10 mol% yttria is particularly preferred.

As the doped ceria, for example, ceria doped with one or more metals selected from the group consisting of Y, Sm, Gd, Nd, Pr, Sc, Ga, and Al, more specifically, Ce _{1 -X} M _X O _2-Y (wherein M represents one or more metals selected from the group consisting of Y, Sm, Gd, Nd, Pr, Sc, Ga, Al; 0.05 ≦ x ≦ 0.4 and 0 ≦ y <0.5). As the doped ceria, in particular, ceria doped with 10 to 30 mol% in Y, Sm and / or Gd, that is, in the above formula, M is Y, Sm and / or Gd and 0.10 ≦ x ≦ 0.30 Certain ceria is preferred, and ceria doped with 15 to 25 mol% of Sm and / or Gd is more preferred.

Note that the value of y in the above formula depends on the amount of dopant M ₂ O ₃ and the oxygen partial pressure. That is, although the valence of M may be bivalent, it is usually trivalent, and the chemical formula of the oxide is M ₂ O ₃ , so the value of y decreases as the amount of dopant increases. Further, since the valence of Ce becomes divalent or trivalent due to the influence of oxygen partial pressure or the like, CeO ₂ and CeO _1.5 are mixed in the ceria. Therefore, the value of y is not uniquely determined. However, this is technical common sense for those skilled in the art.

  Examples of stabilized bismuth include bismuth oxide in which one or more rare earth element oxides such as alkaline earth metal oxides such as MgO, CaO, SrO, and BaO are solid-dissolved as a stabilizer. Is mentioned.

As the lanthanum gallate, La _1-x Sr having a basic structure of LaGaO ₃ perovskite, in which a part of La or Ga is substituted with Sr, Ca, Ba, Mg, In, Co, Fe, Ni, Cu or the like. _{x Ga 1-y Mg y O} 3-δ, La 1-x Sr x Ga 1-y Mg y Co z O 3-δ, La 1-x Sr x Ga 1-y Mg y Fe z O 3-δ, La _1-x Sr _x Ga _1-y Mg _y Ni _z O _3-δ (where 0 <x ≦ 0.2, 0 <y ≦ 0.2, 0 <z ≦ 0.1; δ is The lanthanum gallate represented by (showing the amount of oxygen deficiency) is preferable because it shows high oxygen ion conductivity.

  The fuel electrode layer (B) is not particularly limited as long as it is formed of a metal oxide for a fuel electrode of a solid oxide fuel cell. In the present invention, the metal oxide for the fuel electrode is a metal oxide that is reduced during power generation to become a metal having an anode catalytic activity, such a metal oxide and an oxygen ion conductive metal oxide. A mixture of such metal oxides, oxygen ions and electrons, or a mixture of such metal oxides, oxygen ion conductive metal oxides and mixed conductive metal oxides Point to. Examples of the metal oxide that becomes a metal having anode catalytic activity include one or more of nickel oxide, cobalt oxide, copper oxide, iron oxide, and ruthenium oxide. Examples of the oxygen ion conductive metal oxide and mixed conductive metal oxide include the above-mentioned stabilized zirconia, doped ceria, stabilized bismuth and lanthanum gallate. Among these, the metal oxide for the fuel electrode is preferably a mixture of NiO and doped ceria having high electrode activity at low temperatures.

  The air electrode layer (D) is not particularly limited as long as it is formed of a metal oxide for an air electrode of a solid oxide fuel cell. In the present invention, the metal oxide for the air electrode is a metal oxide having a cathode catalytic activity during power generation, a mixture of such a metal oxide and an oxygen ion conductive metal oxide, such a metal oxide. It refers to a mixed conductive metal oxide of a substance, oxygen ions, and electrons, or a mixture of such a metal oxide, an oxygen ion conductive metal oxide, and a mixed conductive metal oxide.

  Examples of the metal oxide having cathode catalytic activity include perovskite structures such as doped lanthanum manganite, doped lanthanum ferrite, doped lanthanum cobalt ferrite, and doped strontium cobaltite. Of these, doped lanthanum cobalt ferrite and doped strontium cobaltite having high electrode activity at low temperatures are preferred. Examples of the oxygen ion conductive metal oxide and mixed conductive metal oxide include the above-mentioned stabilized zirconia, doped ceria, stabilized bismuth and lanthanum gallate. Among these, as the metal oxide for the fuel electrode, a mixture of doped lanthanum cobalt ferrite, doped strontium cobaltite and doped ceria having high electrode activity at a low temperature is preferable.

  The thickness of the electrolyte layer (C) is 5 to 30 μm, preferably 10 to 20 μm. The thickness of the fuel electrode layer (B) is preferably 10 to 100 μm, particularly preferably 20 to 80 μm. The thickness of the air electrode layer (D) is preferably 10 to 50 μm, particularly preferably 20 to 40 μm.

  In the metal-supported solid oxide fuel cell of the above embodiment, since the fuel gas such as hydrogen or hydrocarbon is supplied into the through-holes of the base material having the honeycomb structure, the partition walls are made a reducing atmosphere. Therefore, the surface of the metal barrier is oxidized in order to prevent the barrier rib from being altered when exposed to a reducing atmosphere and to avoid the influence of the heat treatment atmosphere during the formation of the three-layer film cell. It is also possible to coat with an object. In this case, it is not always necessary to cover the entire surface of the partition wall, and there is no problem with the coating ratio that can prevent the above-mentioned alteration. A preferable covering ratio is a case where it is coated at a ratio of at least 50% or more with respect to the total surface area of the partition walls, and more preferably a ratio of 80% or more in order to prevent the partition wall material from being altered. Preferably it is 90% or more.

  As the material of the coating oxide, oxides such as alumina, titania, zirconia, ceria, nickel oxide are preferable.

  The oxide coating method is not particularly limited, and a normal vapor phase method such as vapor deposition or sputtering, or a liquid phase method such as slurry coating or impregnation, can be used. The coating thickness for preventing the influence of the heat treatment atmosphere is 1 to 10 μm, preferably 2 to 8 μm.

  The method for forming each layer of the metal-supported solid oxide fuel cell is not particularly limited, and a fuel electrode (B), a solid electrolyte (C), and an air electrode are formed on a support (A) having a honeycomb structure. If (D) can be arranged in the order of (B), (C), and (D), a known dry method or wet method can be used. In the dry method, for example, direct current heating deposition method, ion beam deposition method, reactive ion beam deposition method, bipolar sputtering method, magnetron sputtering method, reactive sputtering method, tripolar sputtering method, ion beam sputtering method, ion plating Method, hollow cathode beam method, ion beam implantation method, plasma CVD method or high-speed flame spraying method can be used. In the wet method, a coating method, a coating method, a dipping method, an impregnation method, or the like can be used. Furthermore, the above wet method and dry method can be used in combination.

  The present invention will be described in more detail with reference to the following examples. However, the present invention is not limited by the following examples, and is implemented with appropriate modifications within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

Example 1
(Manufacture of cells for metal-supported solid oxide fuel cells)
<Metal support>
A commercially available metal honeycomb made of ferritic stainless steel containing Al and Ti, having a number of holes of 1600 / inch ² , a support diameter of 120 mmφ, a support thickness of 0.025 cm, and a partition wall thickness of 50 μm, Prepared as a support. The ratio (s / t ² ) between the plane area (s) and the square of the thickness (t) is 181,000.

  Further, the flatness of the metal support is measured 5 times using a three-dimensional measuring machine (Mitutoyo, model: FALCIO916, probe is TP2) by placing the metal support on a surface plate. The average value was defined as flatness. The flatness was 9 μm.

<Formation of fuel electrode layer>
Next, a commercially available NiO having an average particle diameter of 2.5 μm, a commercially available 10 mol% scandia 1 mol% ceria-stabilized zirconia powder (10 Sc1CeSZ) having an average particle diameter of 0.6 μm, and a 10 Sc1CeSZ coarse powder having an average particle diameter of 37 μm. The mixed powder (composition ratio: NiO / fine 10Sc1CeSZ / crude 10Sc1CeSZ = 60/20/20% by mass) was mixed with isopropanol and stirred to prepare a thermal spray powder slurry having a powder concentration of 25%.

  Subsequently, the thermal spray powder slurry obtained above was applied to a high-speed flame spraying apparatus (spraying gun model number: AXZ-Gun, manufactured by Witco Japan Co., Ltd., fine powder supply apparatus model number: WSPF-1, manufactured by Witco Japan Co., Ltd.). A carrier gas that also serves as an auxiliary fuel was supplied, and high-speed flame spraying was performed on the metal support to form a fuel electrode layer. The thickness of the formed fuel electrode layer was 40 μm.

<Formation of electrolyte layer>
Next, an electrolyte slurry is prepared by adding 15 parts by mass of a solid binder to a binder composed of a methacrylate copolymer (molecular weight: 85000, glass transition temperature: −8 ° C.) to 100 parts by mass of the fine 10Sc1CeSZ powder. Prepared. After the slurry was screen-printed on the fuel electrode layer, the support side was fired at 1400 ° C. for 3 hours while flowing nitrogen gas, thereby forming an electrolyte layer on the fuel electrode layer. The thickness of the formed electrolyte layer was 15 μm.

<Formation of air electrode layer>
Subsequently, lanthanum cobalt ferrite powder (composition: La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _3-x ) having an average particle diameter of 0.5 μm was added to 10% by mass of ethyl cellulose and α-terpineol. And stirred to prepare an air electrode paste. At this time, the content of the lanthanum cobalt ferrite powder in the obtained paste was 65% by mass. Next, an air electrode layer is formed on the surface of the electrolyte layer using a screen printing method, and fired at 900 ° C. in a nitrogen gas atmosphere to form an air electrode. A cell X for a metal-supported solid oxide fuel cell Got.

(Cooling cycle evaluation of metal-supported solid oxide fuel cell)
Only the produced metal-supported solid oxide fuel cell X and the metal support were placed in a firing furnace in a nitrogen gas atmosphere, and the temperature increase / decrease from room temperature to 800 ° C. was repeated 20 times. The temperature rising time to 800 was set to 2 hours, and the temperature falling time from 800 ° C. to room temperature was set to 5 hours. The cell X and the metal support after exposure to the cooling cycle were placed on a surface plate, and the flatness was calculated in the same manner as described above. Moreover, the interface state of a support body and a fuel electrode layer was observed visually.
The results are shown in Table 1.

(5-cell stack load test of metal-supported solid oxide fuel cell)
Five metal-supported solid oxide fuel cell cells X produced as described above and five metal separators having a diameter of 120 mmφ and a thickness of 0.2 cm were placed between each cell and at the top of the cell. The laminated body was arranged so that the metal separator was positioned on. Next, using a universal material testing machine (Instron Japan Co., Ltd. model 4301), the laminate was loaded with 1 kg / cm ² under the condition of a crosshead speed of 0.5 mm / min. And then held for 1 minute. After releasing the laminate, the damaged state of the five cells X was visually observed.
The results are shown in Table 1.

(Example 2)
(Manufacture of cells for metal-supported solid oxide fuel cells)
<Metal support>
A metal honeycomb having the same material as that of Example 1 and having an opening number of 900 / inch ² , a support diameter of 120 mmφ, a support thickness of 0.03 cm, and a partition wall thickness of 50 μm was prepared as a metal support. The ratio (s / t ² ) between the planar area (s) and the square of the thickness (t) is 126,000. Further, when the flatness was measured in the same manner as in Example 1, it was 14 μm.

<Formation of fuel electrode layer>
A fuel electrode layer was formed in the same manner as in Example 1.
<Formation of electrolyte layer>
A fuel electrode layer was formed in the same manner as in Example 1.

<Formation of air electrode layer>
Lanthanum cobalt ferrite powder (composition: La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O _3-x ) having an average particle size of 3.0 μm was mixed with isopropanol and stirred to obtain a powder concentration of 25%. A thermal spray material powder slurry was prepared. Next, high-speed flame spraying is performed in the same manner as in the formation of the fuel electrode layer except that the slurry for forming the air electrode layer is used as the slurry for forming the air electrode layer instead of the slurry for forming the fuel electrode layer in Example 1, and the electrolyte layer An air electrode layer was formed on the surface of the obtained metal-supported solid oxide fuel cell Y.

(Cooling cycle evaluation of metal-supported solid oxide fuel cell)
The same procedure as in Example 1 was performed except that the metal-supported solid oxide fuel cell Y was used instead of the metal-supported solid oxide fuel cell X. In addition, the metal support was similarly subjected to a thermal cycle evaluation, and the flatness was calculated.
The results are shown in Table 1.

(5-cell stack load test of metal-supported solid oxide fuel cell)
The same procedure as in Example 1 was performed except that the metal-supported solid oxide fuel cell Y was used instead of the metal-supported solid oxide fuel cell X.
The results are shown in Table 1.

(Comparative Example 1)
<Metal support>
A metal support made of ferritic stainless steel containing Al and Ti, having a number of holes of 60 / inch ² , a support diameter of 100 mmφ, a support thickness of 0.1 cm, and a partition wall thickness of 300 μm. Prepared as. The ratio (s / t ² ) between the plane area (s) and the square of the thickness (t) is 7,900. The flatness measured in the same manner as in Example 1 was 5 μm.

<Formation of fuel electrode layer>
A fuel electrode layer was formed in the same manner as in Example 1.
<Formation of electrolyte layer>
A fuel electrode layer was formed in the same manner as in Example 1.
<Formation of air electrode layer>
A fuel electrode layer was formed in the same manner as in Example 1 to obtain a metal-supported solid oxide fuel cell Z.

(Cooling cycle evaluation of metal-supported solid oxide fuel cell)
It replaced with the metal support type solid oxide fuel cell X, and it carried out by the same method as Example 1 except using the cell Z for metal support type solid oxide fuel cells.
The results are shown in Table 1.

(5-cell stack load test of metal-supported solid oxide fuel cell)
It replaced with the metal support type solid oxide fuel cell X, and it carried out by the same method as Example 1 except using the cell Z for metal support type solid oxide fuel cells.
The results are shown in Table 1.

  From Table 1 above, the flatness of the metal-supported solid oxide fuel cell of the present invention is 30 μm or less, but it is not tripled compared to the flatness of the metal support. Also, no damage was observed in the load test of the 5-cell stack.

  On the other hand, although it is excellent when the flatness of the cell which is not the present invention is 20 μm or less, it is 3 times or more as compared with the flatness of the metal support, and it can be seen that the ratio of twist and deflection is large. Moreover, since damage was recognized in the load test of the 5-cell stack, it can be said that the buffering action of the metal support having a honeycomb structure is not sufficient.

  According to the metal-supported solid oxide fuel cell of the present invention, the three-layer membrane is excellent in cell strength and has rigidity against torsion and deflection even after repeated cooling and heating cycles, and the buffering action of the honeycomb-structured metal support. Since breakage of the cell is unlikely to occur, an excellent metal-supported solid oxide fuel cell and a solid oxide fuel cell using such a cell can be provided.

Claims (4)

A support body (A) comprising a metal partition, comprising a plurality of through holes, having a honeycomb structure with a number of through holes in the range of 25 to 2000 / inch ² and a thickness (t) of 0.01 to 0.2 cm. ), A fuel electrode (B), a solid electrolyte (C), and an air electrode (D) are arranged in the order of (B), (C), (D). Oxide fuel cell. ^2. The metal support according to claim 1, wherein a ratio (s / t ² ) between a planar area (s) of the support (A) and a square of the thickness (t) is in a range of 10,000 / 1 to 400,000 / 1. Type solid oxide fuel cell. 3. The metal-supported solid oxide fuel cell according to claim 1, wherein the support (A) has a planar area (s) of 50 to 1000 cm ² .   A solid oxide fuel cell comprising the metal-supported solid oxide fuel cell according to any one of claims 1 to 3.

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