JP2005150053A - Solid electrolyte fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell in which gas-sealing is facilitated and there is little possibility that cross-leak of gas occurs. <P>SOLUTION: The solid electrolyte fuel cell is provided with: a metallic cell substrate 2 having a gas permeation hole 2a; a battery element 6 formed by pinching an electrolyte layer 5 between a pair of electrode layers 3, 4; and a cell 7 made by covering either one of the electrode layers 3 of the pair of electrode layers 3, 4 of the battery element 6 positioned on the gas permeable hole 2a of the metallic cell substrate 2, and also provided with a conductive metal thin plate 8 for cell support to support the cell 7 by joining to the gas impermeable part 2b of the metallic cell substrate 2. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a solid oxide fuel cell having a configuration in which a solid electrolyte is sandwiched between a pair of electrodes as a battery element.

  As a conventional solid oxide fuel cell, for example, a cell substrate made of a porous body and a battery element formed by sandwiching an electrolyte layer between a pair of electrode layers are laminated on the cell substrate. Some of them are equipped with cells. In this solid oxide fuel cell, the electrolyte layer of the battery element and the cell support that supports the cells are joined together.

JP 2000-331692 A

  However, in the conventional solid oxide fuel cell, since the cell substrate is made of a porous body, it is necessary to seal the portion where the battery element is not formed, and the electrolyte layer and cell of the battery element The thermal stress generated at the joint with the support, that is, the joint between the ceramic layer and the metal, may cause the joint to deteriorate and break, resulting in gas cross-leakage. There has been a problem that there is no problem, and it has been a conventional problem to solve this problem.

  The present invention has been made by paying attention to the above-described conventional problems, and an object thereof is to provide a solid oxide fuel cell that facilitates gas sealing and has almost no possibility of causing gas cross-leakage. .

  The present invention comprises a metal cell substrate having a gas permeable hole and a battery element formed by sandwiching an electrolyte layer between a pair of electrode layers, and a pair of battery elements positioned on the gas permeable hole of the metal cell substrate. In a solid oxide fuel cell having a cell formed by covering any one of the electrode layers with an electrolyte layer, the conductive layer is bonded to a gas-impermeable portion of the metal cell substrate to support the cell. The present invention is characterized in that a metal thin plate for supporting a cell having conductivity is provided, and the configuration of the solid oxide fuel cell is used as a means for solving the above-described conventional problems.

  According to the solid oxide fuel cell of the present invention, since it has the above-described configuration, gas sealing becomes easy, and in addition, the gas is obtained by joining the cell and the cell supporting metal thin plate to each other. It is possible to eliminate the fear of the occurrence of the cross leak, and further, it is possible to provide a very excellent effect that the cell supporting metal thin plate joined to the cell can function as a current collector.

  As shown in FIG. 1, a solid oxide fuel cell 1 of the present invention includes an electrolyte layer 5 between a metal cell substrate 2 having a gas permeation hole 2a and a pair of electrode layers (a fuel electrode layer 3 and an air electrode layer 4). The battery element 6 is formed by sandwiching the electrode element, and one of the electrode layers 3 and 4 of the battery element 6 positioned on the gas permeation hole 2a of the metal cell substrate 2 (see FIG. In the example shown, a cell 7 is formed by covering the fuel electrode layer 3) with the electrolyte layer 5, and the gas-impermeable portion 2b of the metal cell substrate 2 is provided with a cell support having electric conductivity for supporting the cell 7. A thin metal plate 8 is joined. At this time, since there is no gas leak from the metal cell substrate 2, the degree of freedom of the joining layout between the metal cell substrate 2 and the cell supporting metal thin plate 8 is high, and the cell supporting metal is shown on the upper surface of the metal cell substrate 2 in the drawing. In addition to being able to be joined to the thin plate 8, it is possible to join the cell supporting metal thin plate 8 on the lower surface of the metal cell substrate 2 as shown in FIG. 2.

  As a material of the cell supporting metal thin plate 8, a metal or an alloy containing at least one element of Fe, Ni, Cr, Mo, Cu, and Al is used. Examples of the alloy include Inconel, Hastelloy, stainless steel, and Invar.

  Further, in the solid oxide fuel cell 1 of the present invention, it is desirable that the thickness of the joint portion 8 a of the cell supporting metal thin plate 8 with the metal cell substrate 2 is thinner than that of the metal cell substrate 2. At this time, as shown in FIG. 3, the thickness of the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2 is made the same as the entire thickness of the cell supporting metal thin plate 8, or as shown in FIG. In addition, the thickness of the joint portion 8 a of the cell supporting metal thin plate 8 with the metal cell substrate 2 can be made thinner than the entire thickness of the cell supporting metal thin plate 8.

  In this way, by using the cell supporting metal thin plate 8 that is thinner than the metal cell substrate 2, the cell supporting metal thin plate 8 is deformed when the metal cell substrate 2 and the cell supporting metal thin plate 8 are joined. By doing so, the damage of the cell 7 by a joining process and the deformation | transformation of the metal cell board | substrate 2 can be prevented. In addition, it is possible to prevent the cell 7 from being damaged by the deformation of the cell supporting metal thin plate 8 against the thermal stress caused by the thermal cycle during the stack operation.

  However, when the thickness of the joining portion 8a of the cell supporting metal thin plate 8 is 30 μm or less, a portion where the cell supporting metal thin plate 8 is largely deformed when joining to the cell 7 or the stack manifold is generated, There are concerns about the occurrence of gas leaks and breakage of the joint 8a.

  Further, if the total thickness of the cell supporting metal thin plate 8 is 30 μm or less, it becomes difficult to handle the cell supporting metal thin plate 8 during each process, and problems may occur in the formation of a gas seal and the joining with the manifold. Concerned. On the other hand, if the total thickness of the cell supporting metal thin plate 8 is larger than 0.5 mm, the strength of the cell supporting metal thin plate 8 is equal to or higher than that of the cell main body. There is a risk that the cell 7 may be damaged by the force of deforming, or the joint portion 8a may be damaged by the force that releases the residual stress.

  Furthermore, in the solid oxide fuel cell of the present invention, it is desirable to provide a stress relaxation portion at or near the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2.

  That is, the stress relaxation portion is preferentially deformed by the stress generated when the metal cell substrate 2 and the cell supporting metal thin plate 8 are joined, so that the metal cell substrate 2 is damaged and the cell supporting metal thin plate 8 is deformed. Problems such as warping can be suppressed, and when the cell supporting metal thin plate 8 is laminated when forming the stack structure, the metal cell substrate 2 is damaged or becomes a starting point of stress absorption or stress release. The deformation of the cell supporting metal thin plate 8 is suppressed, and furthermore, it becomes a starting point of stress absorption or stress release against thermal stress due to the thermal cycle at the time of stack operation, the metal cell substrate 2 is damaged, the cell supporting metal thin plate It is possible to prevent the deformation of the stack 8 and the damage to the stack structure.

  In this case, the thickness of the joining portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2 is made thinner than the other portions to form a stress relaxation portion, or the metal cell substrate 2 of the cell supporting metal thin plate 8 is used. The periphery of the joint portion 8a is thinned locally to form a stress relaxation portion, or the periphery of the joint portion 8a of the cell supporting metal thin plate 8 to the metal cell substrate 2 is swelled to form a stress relaxation portion. In addition, a step can be provided around the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2 to form a stress relaxation portion.

  Here, when the thickness of the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2 is made thinner than the other portions to form a stress relieving portion, the other portions as shown in FIG. The thickness may be made even more uniform, or as shown in FIG. 5, it may be made gradually thinner toward the end of the joint portion 8a.

  Further, “to locally thin the periphery of the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2” means that the joint portion is locally formed around the joint portion 8a as shown in FIG. That is, a thin part (stress relaxation part) 10 thinner than 8a is provided, and the thin part 10 can be disposed at a plurality of locations as shown in FIGS.

  Further, “undulate the periphery of the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2” means that a wavy portion having a U-shaped cross section around the joint portion 8a (see FIG. 9). Stress relieving part) 10, and the wavy part 10 can be disposed at a plurality of locations as shown in FIG. 10.

  Furthermore, “a step is provided around the joint portion 8a of the cell supporting metal thin plate 8 with the metal cell substrate 2” means that the joint portion 8a is surrounded by a portion as shown in FIGS. That is, the uneven portion (stress relaxation portion) 10 is formed.

  Furthermore, since the smaller the Young's modulus, the smaller the deformation (elongation), that is, the easier it is to deform with respect to the stress, in the solid oxide fuel cell 1 of the present invention, the cell supporting metal It is desirable to set the Young's modulus of the thin plate 8 to be smaller than the Young's modulus of the metal cell substrate 2. In addition to this, as described above, if the thickness of the cell supporting metal thin plate 8 is reduced, or if the stress relaxation portion 10 such as a thin portion or a wavy portion is formed around the joining portion 8a, the cell supporting metal The thin plate 8 is easily deformed, and the cell 7 can be more reliably prevented from being damaged.

  Furthermore, in the solid oxide fuel cell 1 of the present invention, the cell supporting metal thin plate 8 and the metal cell substrate 2 can be bonded by diffusion bonding. Here, “diffusion bonding” includes brazing using a brazing material, but regardless of whether or not the brazing material is used, the joining portion 8a is exposed to a high temperature, and between the members to be joined, An alloy layer (diffusion layer) of a brazing material and a base material is formed and integrated (joined). Generally, diffusion bonding including brazing is a high-temperature process, in which members to be bonded are exposed to a high temperature for bonding.

  At this time, the metal cell substrate depends on the elongation rate, thermal expansion coefficient, heat capacity, and diffusion depth of each member (which side of the metal cell substrate 2 or the cell supporting metal thin plate 8 is likely to form a diffusion layer). Tensile stress or compressive stress is generated in any of 2 and the cell supporting metal thin plate 8. In addition, a torsional stress is also generated due to the release of the stress inherent in the metal cell substrate 2 and the cell supporting metal thin plate 8. If the cell supporting metal thin plate 8 does not have a starting point for stress absorption (or release), that is, if there is no stress relaxation portion 10, the metal cell substrate 2 is damaged or the cell supporting metal thin plate 8 is warped. Thus, there is a concern about the damage of the cell 7 or the occurrence of gas leak as described above.

  Furthermore, in the solid oxide fuel cell 1 of the present invention, the cell supporting metal thin plate 8 and the metal cell substrate 2 can be bonded by ultrasonic bonding. This ultrasonic bonding can be bonded at a lower temperature than the diffusion bonding described above. This is a possible process in metal / metal bonding and is not suitable for ceramic / metal bonding as in the prior art. Moreover, when this construction method is used for the joining of the electrolyte layer and the metal thin plate shown in the prior art, there is a risk that the electrolyte layer is damaged, and gas leakage from the damaged part and separation of the joint interface from the damaged part occur.

  Therefore, in the solid oxide fuel cell 1 of the present invention, since the cell supporting metal thin plate 8 and the metal cell substrate 2 are both made of metal members, the cell supporting metal thin plate 8 and the metal cell substrate 2 are formed. Without being exposed to an excessively high temperature, the process can be shifted to a stack forming process, and the gas seal construction of the laminated portion of the cell supporting metal thin plate 8 is facilitated.

  Furthermore, in the solid oxide fuel cell 1 of the present invention, since the cell supporting metal thin plate 8 and the metal cell substrate 2 are both made of metal, the cell supporting metal thin plate 8 and the metal The cell substrate 2 can be joined by welding while maintaining electrical continuity. Here, the welding includes laser beam welding, precision welding, TIG welding, arc welding, overlay welding, and a joining method similar to welding such as gas deposition and spark deposition can be used. Also in this case, since the bonding at a low temperature is possible, the cell supporting metal thin plate 8 and the metal cell substrate 2 can be transferred to a stack forming process without being exposed to an excessively high temperature, and the cell supporting metal thin plate 8 is laminated. Gas seal construction of the part becomes easy.

  Here, when the large metal cell substrate 2 is joined to the cell supporting metal thin plate 8, a portion requiring gas sealing becomes long (wide). In addition, since the distance between the gas seal portion and the central portion of the cell 7 is increased, the stress on the gas seal portion such as a heat cycle during operation is increased, and there is a concern that the gas seal portion is damaged. Furthermore, when the joining part of one metal cell substrate 2 becomes long, there is a concern about the influence on the yield of the gas seal part.

  On the other hand, if a plurality of small metal cell substrates 2 are arranged in a dispersed manner, the total gas seal portion becomes longer, but the above-mentioned concerns can be eliminated. Reliability is improved. When considering a solid oxide fuel cell stack structure as a power source for movement, for example, a stack structure as a portable generator and a main power source for an automobile also have an output required for the stack structure. Although the required sizes are different, the metal cell substrates 2 having sizes suitable for each are manufactured, and the same metal cell substrate 2 is arranged on the cell supporting metal thin plate 8 in accordance with the required value of the stack rather than stacking. Therefore, there is a manufacturing and production merit that the cost of the cell 7 can be reduced and the stack design can be easily changed. Therefore, in the solid oxide fuel cell of the present invention, the cell supporting metal It is desirable to arrange a plurality of cells 7 on the thin plate 8.

  For example, as shown in FIG. 13, one or more openings 8b (regardless of the size of the openings) are formed in the cell supporting metal thin plate 8, and the cells 7 are arranged in these openings 8b, respectively. Can be bonded to the gas-impermeable portion 2b of the metal cell substrate 2 of the cell 7, and at this time, a configuration is adopted in which one cell 7 is disposed in one opening 8b. In addition, it is possible to employ a configuration in which one cell 7 is arranged with respect to the plurality of openings 8b.

  And in this invention, the solid oxide fuel cell 1 shown in FIG. 1 (FIG.13 (d)) formed by joining the cell supporting metal thin plate 8 to the surface by the side of the battery element 6 of the metal cell board 2 in the cell 7. And a solid oxide fuel cell 1 (FIG. 13 (c)) shown in FIG. 2 in which a cell supporting metal thin plate 8 is joined to the surface of the cell 7 opposite to the battery element 6 of the metal cell substrate 2. As shown in FIG. 13A, the stack structure 15 of the solid oxide fuel cell 1 can be formed.

  Thus, the solid oxide fuel cell 1 formed by joining the cell supporting metal thin plate 8 to the surface of the metal cell substrate 2 on the battery element 6 side, and the battery element 6 of the metal cell substrate 2 on the opposite side. The solid electrolyte fuel cells 1 formed by joining the cell supporting metal thin plates 8 on the surface are alternately stacked on top and bottom, so that the stress at the time of joining can be offset and the cell supporting metal thin plates 8 can be further deformed. This is extremely effective when forming the stack structure 15.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, this invention is not limited to a following example.

[Example 1]
As shown in FIG. 1, a ferrite cell SUS having a diameter of 30 mm and a thickness of 100 μm was used as the metal cell substrate 2.

  Then, the 8YSZ electrolyte layer 5 is formed in a range of φ26 mm from the center on the metal cell substrate 2 made of ferrite-based SUS by using an aerosol deposition method. In this aerosol deposition method, YSZ raw material powder having an average particle diameter of 0.2 μm is used, He gas is blown at 8 L / min while the solubilizing chamber is vibrated at 150 rpm, and is conveyed to the nozzle in the film forming chamber. .

  Next, a photo-curing resin layer for an etching mask is formed on the front and back of the metal cell substrate 2 on which the YSZ film is formed. On the back surface of the YSZ film formation, a pattern of 300 pieces having a diameter of 500 μm with respect to a range of 20 mm from the center. A mask layer was formed. The metal cell substrate 2 was etched using a known iron chloride-based etchant to form a porous portion (cell portion) capable of generating power.

Next, a lanthanum-gallium-cobalt oxide ((La0.8 Sr0.2) CoO ₃ ) was formed as an air electrode layer 4 on the upper surface of the electrolyte layer 5 by using an aerosol deposition method. The raw material powder had an average particle size of 0.5 μm, a vibration of 159 rpm in the sol chamber, a He gas blowing rate of 8 L / min, a vacuum in the chamber of 1.5 Torr, and a film thickness of 6 μm. Subsequently, a cell 7 was obtained by forming a Ni—YSZ cermet layer as a fuel electrode layer 1 in a thickness of 1 μm in a porous portion on the back surface of the metal cell substrate 2 using a known sputtering method.

  The cell 7 thus obtained was joined to the ferrous SUS cell supporting metal thin plate 8 having an outer diameter of φ60 mm, an inner diameter of φ25, and a thickness of 100 μm, and the solid oxide fuel cell of this example. 1 was obtained.

  At this time, an Ag—Cu brazing paste is printed and applied in a width of 2 mm and a thickness of 30 μm around the inner periphery of the ferrous SUS cell supporting metal thin plate 8, and an outer diameter is applied on the Ag—Cu brazing paste. The cell 7 and the cell supporting metal thin plate 8 were joined by placing the cell 7 having a diameter of 30 mm and performing a heat treatment at 750 ° C. for 2 hours in Ar carrier gas 0.8 torr.

[Example 2]
As shown in FIG. 2, Inconel 625 having a diameter of 30 mm and a thickness of 100 μm was used as the metal cell substrate 2.

  Then, a NiO—YSZ layer was formed as the fuel electrode layer 3 on the metal cell substrate 2 made of Inconel 625 by high-temperature sputtering (substrate heating 300 ° C.).

  Next, a YSZ film 5 is formed on the NiO-YSZ layer by substrate heating and bias application sputtering (substrate heating 700 ° C., application bias 25 V) so as to completely cover the NiO—YSZ layer.

Next, samarium-strontium-cobalt oxide ((Sm0.5, Sr0.5) CoO ₃ ) was formed as the air electrode layer 4 on the YSZ layer as the electrolyte layer 5 by high-temperature sputtering (substrate heating 300 ° C.). .

  After the battery element 6 is formed on the metal cell substrate 2, a mask layer is formed on the back surface of the YSZ film by forming a pattern of 300 pieces with a diameter of 500 μm with respect to a range of 20 mm from the center. Are used to form a large number of φ500 μm recesses (gas permeation holes) 2a having a plurality of fine holes formed in the lower part.

  The above-mentioned chemical etching process used for microhole etching is, for example, a surface roughening agent (used for roughening the surface of the wiring in order to improve the adhesion between the wiring and the resin in the printed circuit board manufacturing process ( For example, a Meck nickel roughener 1870) can be used.

  The cell 7 thus obtained was joined to the cell support metal thin plate 8 made of Inconel 625 having a donut shape with an outer diameter of 60 mm, an inner diameter of 25, and a thickness of 100 μm, and the solid oxide fuel cell 1 of this example was used. Got.

  At this time, an Ag—Cu-based brazing paste is printed on the inner periphery of the cell supporting metal thin plate 8 made of Inconel 625 with a width of 2 mm and a thickness of 30 μm, and an outer diameter of φ30 mm is formed on this Ag-Cu-based brazing paste. The cell 7 and the cell supporting metal thin plate 8 were joined by performing a heat treatment at 750 ° C. for 2 hours in Ar carrier gas 0.8 torr.

[Example 3]
The cell 7 obtained in Example 2 was joined to the cell-supported metal thin plate 8 made of ferrite SUS having an outer diameter of 60 mm, an inner diameter of 25, and a thickness of 80 μm, and the solid oxide fuel cell of this example. 1 was obtained.

Here, the Young's modulus (0.2% Yield Strengths) of the metal cell substrate 2 and the cell supporting metal thin plate 8 in the vicinity of the junction temperature is as follows: ferrite SUS: about 150 [MPa / m ² ], inconel 625: about 350 [MPa / m ² ], and the cell supporting metal thin plate 8 is more easily deformed than the metal cell substrate 2.

  At this time, an Ag—Cu brazing paste is printed and applied in a width of 2 mm and a thickness of 30 μm around the inner periphery of the ferrous SUS cell supporting metal thin plate 8, and an outer diameter is applied on the Ag—Cu brazing paste. The cell 7 and the cell supporting metal thin plate 8 were joined by mounting the cell 7 having a diameter of 30 mm and performing a heat treatment at 750 ° C. for 2 hours in Ar carrier gas 0.8 torr.

[Example 4]
As shown in FIG. 3, the cell 7 obtained in Example 2 was joined to the cell-supporting metal thin plate 8 made of ferrite SUS having a donut shape having an outer diameter of 60 mm, an inner diameter of 25, and a thickness of 100 μm. An example solid oxide fuel cell was obtained.

  At this time, the cell 7 having an outer diameter of 30 mm is placed on the inner periphery of the cell-supporting metal thin plate 8 made of ferritic SUS, and the cell-supporting metal thin plate 8 and the cell 7 overlap each other (approximately 2.5 mm width). The ultrasonic seam bonding was performed by applying an ultrasonic vibration of approximately 20 kHz.

[Example 5]
As shown in FIG. 4, 500 through-holes having a diameter of 500 μm are formed by chemical etching in the inner diameter of 20 mm in the metal cell substrate 2 made of Inconel 625 having a diameter of 30 mm and a thickness of 200 μm. Used as.

  Next, Ni + SDC paste was applied by screen printing in the range of φ25 mm on the metal cell substrate 2 made of Inconel 625, and baked at 1100 ° C. in a 10% hydrogen (Ar base) atmosphere. At this time, the Ni + SDC layer as the fuel electrode layer 3 was about 100 μm at a location where the through hole of the metal cell substrate 2 was not formed.

  Next, as the electrolyte layer 5 in the thin film battery element 6 on the Ni + SDC layer of the metal cell substrate 2 made of Inconel 625, a YSZ layer having a thickness of 8 μm is heated (700 ° C.) and bias is applied to the metal cell substrate 2. Obtained by sputtering (applied bias 25 V).

  Then, an SSC layer having a porosity of 30% and a film thickness of 40 μm is formed on the YSZ film as the air electrode layer 4 in the thin film battery element 6 by heat sputtering of the metal cell substrate 2 (substrate temperature 300 ° C.). 7 was obtained.

  A cell support metal thin plate made of ferritic SUS having a stepped donut shape with the cell 7 thus obtained and a thickness of 80 μm in the range of outer diameter φ60 mm, inner diameter φ25 mm, inner width 5 mm, and other thickness 200 μm. 8 was joined to obtain a solid oxide fuel cell 1 of this example.

  At this time, the metal cell substrate 2 and the cell supporting metal thin plate 8 were joined by YAG laser welding. The YAG laser welding was performed by irradiating a YAG laser having a pulse energy of 2 [J] and a pulse width of 0.1 [ms] perpendicularly from the cell supporting metal thin plate 8 side.

[Example 6]
As shown in FIG. 13, eight through-holes (openings) 8b of φ26 mm are formed by chemical etching on a ferrite-type SUS donut-shaped thin plate having an outer diameter of φ125 mm, an inner diameter of φ40 mm, and a thickness of 100 μm, and then φ26 mm A step 8c was formed by pressing in the range of the peripheral width of 5 mm of the through hole 8b to obtain a metal thin plate 8 for cell support.

  The steps 8c formed around the φ26mm through hole 8b of the doughnut-shaped thin plate are not all formed on the same side of the cell supporting metal thin plate 8, but the steps 8c formed in the adjacent through holes 8b are staggered. It is formed so as to be in the direction. Further, the thickness of the step 8c is reduced from 100 μm to 80 μm in the same manner as the cell supporting metal thin plate 8 shown in FIG. 4, and functions as a stress relaxation portion.

  The cell supporting metal thin plate 8 and the cell 7 shown in FIG. 4 are welded using a YAG laser in the same manner as in the fifth embodiment. In addition, in the location where the level | step difference 8c is formed so that it may become convex on the surface side, as shown in FIG.13 (d), the back surface side of the metal thin plate 8 for cell support and the surface side of the cell 7 are joined, and back surface side As shown in FIG. 13C, the front surface side of the cell supporting metal thin plate 8 and the back surface side of the cell 7 are joined at a location where the step 8c is formed so as to be convex.

  In the present invention, as described above, since the bonding between the cell and the metal thin plate for supporting a cell is a bonding between metals, not only the heat cycle is strengthened, but the number of options for the bonding method is increased, and the bonding itself Will also be easier.

It is a section explanatory view showing one example of a solid oxide fuel cell of the present invention. (Example 1) It is a section explanatory view showing other examples of a solid oxide fuel cell of the present invention. (Examples 2 and 3) FIG. 6 is a cross-sectional explanatory view showing still another embodiment of the solid oxide fuel cell of the present invention. (Example 4) FIG. 6 is a cross-sectional explanatory view showing still another embodiment of the solid oxide fuel cell of the present invention. (Example 5) FIG. 6 is a cross-sectional explanatory view showing still another embodiment of the solid oxide fuel cell of the present invention. FIG. 6 is a cross-sectional explanatory view showing still another embodiment of the solid oxide fuel cell of the present invention. FIG. 7 is a partial cross-sectional explanatory view showing another modification of the stress relaxation portion in the solid oxide fuel cell of FIG. 6. FIG. 9 is a partial cross-sectional explanatory view showing still another modification of the stress relaxation portion in the solid oxide fuel cell of FIG. 6. FIG. 6 is a cross-sectional explanatory view showing still another embodiment of the solid oxide fuel cell of the present invention. FIG. 10 is a partial cross-sectional explanatory view showing another modification of the stress relaxation portion in the solid oxide fuel cell of FIG. 9. FIG. 10 is a partial cross-sectional explanatory view showing still another modified example of the stress relaxation portion in the solid oxide fuel cell of FIG. 9. FIG. 10 is a partial cross-sectional explanatory view showing still another modified example of the stress relaxation portion in the solid oxide fuel cell of FIG. 9. The cross-sectional explanatory drawing (a) which shows one Example of the stack structure of the solid oxide fuel cell of this invention, the plane explanatory drawing (b) of a solid oxide fuel cell, and the AA line in FIG.13 (b) It is sectional explanatory drawing (d) based on the BB line in sectional explanatory drawing (c) and FIG.13 (b). (Example 6)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid electrolyte fuel cell 2 Metal cell board 2a Gas permeation hole 2b Gas impermeability part 3 Fuel electrode layer (electrode layer)
4 Air electrode layer (electrode layer)
DESCRIPTION OF SYMBOLS 5 Electrolyte layer 6 Battery element 7 Cell 8 Metal thin plate for cell support 8a Joint part 8b Opening 8c Step 10 Stress relaxation part 15 Stack structure of solid electrolyte fuel cell

Claims (14)

A battery cell element formed by sandwiching an electrolyte layer between a metal cell substrate having a gas permeable hole and a pair of electrode layers, and a pair of electrode layers of the battery element positioned on the gas permeable hole of the metal cell substrate; In a solid oxide fuel cell comprising a cell formed by covering one of the electrode layers with an electrolyte layer,
A solid oxide fuel cell comprising a thin metal plate for supporting a cell having electrical conductivity which is bonded to a gas-impermeable portion of the metal cell substrate and supports the cell.   2. The solid oxide fuel cell according to claim 1, wherein a thickness of a joint portion between the cell supporting metal thin plate and the metal cell substrate is made thinner than that of the metal cell substrate.   3. The solid oxide fuel cell according to claim 1, wherein a stress relaxation portion is provided at or around a joint portion of the metal thin plate for cell support with a metal cell substrate.   4. The solid oxide fuel cell according to claim 3, wherein the thickness of the joint portion of the metal thin plate for cell support with the metal cell substrate is made thinner than the other portions to form a stress relaxation portion.   The solid oxide fuel cell according to claim 3, wherein the periphery of the joint portion between the metal thin plate for cell support and the metal cell substrate is locally thinned to form a stress relaxation portion.   4. The solid oxide fuel cell according to claim 3, wherein a stress relaxation portion is formed by undulating the periphery of the joint portion of the cell supporting metal thin plate with the metal cell substrate.   4. The solid oxide fuel cell according to claim 3, wherein a step is provided around a joint portion between the thin metal plate for cell support and the metal cell substrate to form a stress relaxation portion.   The solid oxide fuel cell according to any one of claims 1 to 7, wherein the Young's modulus of the cell supporting metal thin plate is set smaller than the Young's modulus of the metal cell substrate.   The solid oxide fuel cell according to any one of claims 1 to 8, wherein the cell supporting metal thin plate and the metal cell substrate are bonded by diffusion bonding.   The solid oxide fuel cell according to any one of claims 1 to 4, wherein the cell supporting metal thin plate and the metal cell substrate are bonded by ultrasonic bonding. The solid oxide fuel cell according to claim 4, wherein the cell supporting metal thin plate and the metal cell substrate are joined by welding.   The solid oxide fuel cell according to any one of claims 1 to 11, wherein a plurality of cells are arranged on a metal thin plate for cell support.   The thin metal plate for supporting a cell has at least one opening, and a cell is disposed in the opening, and a peripheral portion of the opening is joined to a gas-impermeable portion of a metal cell substrate of the cell. The solid oxide fuel cell as described.   The solid oxide fuel cell according to any one of claims 1 to 13, and a metal cell substrate in the cell, wherein a cell supporting metal thin plate is joined to a surface on the battery element side of the metal cell substrate in the cell. 14. A solid electrolyte type obtained by alternately laminating a solid oxide fuel cell according to any one of claims 1 to 13, wherein a cell supporting metal thin plate is joined to a surface opposite to the battery element. Fuel cell stack structure.

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