JPH10312818A - Solid electrolyte type fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stable operation by eliminating a possible damage caused by a cross leak of fuel gas and oxidizer gas. SOLUTION: A fuel cell is provided by laminating a cell 10 made by forming an anode layer 12, an electrolyte layer 13 and a cathode layer 14 on a cell base plate 11 with a separator 15 equipped with a passage groove 20 for fuel gas and another passage groove for oxidizer gas. The cell base plate 11 of the cell 10 is embedded and assembled in a recessed part provided on a surface of the separator 15, and a side of the cell base plate 11 is covered by a separator 15 in order to prevent reacting gas introduced to the cell base plate 11 from being leaked from the side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solid oxide fuel cell, and more particularly to a solid electrolyte fuel cell of a flat-plate type supporting membrane type using a cell formed by laminating an electrolyte layer and an electrode layer on a substrate.

[0002]

2. Description of the Related Art A solid oxide fuel cell using an oxide solid electrolyte such as zirconia has an operating temperature of about 1,000.
Because of its high temperature of ℃, the power generation efficiency is high and a catalyst is not required.In addition, the electrolyte is solid, which makes it easy to handle, and is expected to play a role in future power generation systems. I have.

However, a solid oxide fuel cell is
Since ceramics are the main constituent material, they are easily damaged by thermal shock or thermal stress, and it has been difficult to realize this method because there is no appropriate gas sealing method. Therefore, a specially shaped cylindrical fuel cell has been devised to solve these problems.However, the cylindrical type has a lower power density per unit volume than the flat type in principle. Has been pointed out. On the other hand, in a flat plate type which is expected to have a high output density, a supporting film type in which an electrode layer and a solid electrolyte layer are formed on a cell substrate has been proposed as a method for obtaining a large output by increasing the area.

FIG. 8 is an exploded perspective view showing a basic structure of a conventional solid electrolyte fuel cell of a flat support type. A solid plate made of yttria-stabilized zirconia is placed on an anode porous substrate 1 made of nickel and yttria-stabilized zirconia cermet and provided with a fuel gas flow hole 5 and an oxidizing gas flow hole 6 at the outer edge of the flat plate. Electrolyte layer 2 and cathode layer 3 composed of lanthanum manganite
Are sequentially formed using a method such as a plasma spraying method, thereby forming the cell 4. After a glass paste is applied to the side surface of the cell 4 configured as described above, Ni-
A battery laminate is constituted by alternately laminating the separators 7 made of a Cr alloy. Each of the sealing material 8 and the separator 7 has a fuel gas flow hole 5 of the cell 4.
A communication hole is provided to communicate with the oxidant gas communication hole 6 and a plurality of fuel gas communication grooves 9 are formed in the separator 7 on the surface of the cell 4 facing the anode porous substrate 1. ,
An oxidizing gas flow groove (not shown) extending in a direction orthogonal to the fuel gas flow groove 9 is provided on a surface facing the cathode layer 3.

The fuel gas supplied from the outside flows through one fuel gas passage 5 and is sent into the inside of the battery stack.
After splitting and flowing through the fuel gas flow grooves 9 of each separator 7, the fuel gas flows through the other fuel gas flow holes 5 and is discharged to the outside. Similarly, the oxidizing gas is also supplied from one oxidizing gas flow hole 6, flows through the oxidizing gas flow groove, and then is discharged from the other oxidizing gas flow hole 6.
The fuel gas flowing through the fuel gas flow groove 9 diffuses inside the porous anode substrate 1 and reaches the solid electrolyte layer 2.
The oxidant gas flowing through the oxidant passage is reduced in the cathode layer 3, becomes oxygen ions, diffuses inside the solid electrolyte layer 2, and reacts with hydrogen of the fuel gas at the interface with the anode porous substrate 1. Reacts to produce water.

[0006]

In the conventional solid electrolyte fuel cell of the flat support type, the fuel cell and the oxidizing gas are separated airtightly by forming the cell stack as described above. Power is supplied to each electrode layer to generate power by an electrochemical reaction. However, in the present configuration, as described above, the leakage of the fuel gas or the oxidizing gas is prevented by applying the glass paste to the side surface of the cell 4, but the glass paste does not always have a sufficient sealing performance. There is a disadvantage that the sealing performance deteriorates when subjected to a heat cycle. Further, since the sealing material 8 interposed between the cell 4 and the separator 7 is also made of Pyrex glass, it is similarly vulnerable to a heat cycle, and the sealing performance is deteriorated when subjected to an excessive heat cycle,
There is a risk of cross-leak between the fuel gas and the oxidizing gas. As described above, when the cross leak between the fuel gas and the oxidizing gas occurs, not only does the battery characteristic deteriorate significantly, but in the worst case, the battery stack is damaged.

An object of the present invention is to provide a fuel gas system and an oxidizing gas system which are hermetically sealed from each other even when subjected to a heat cycle accompanying a power generation operation, and damage caused by cross leak of the fuel gas and the oxidizing gas. It is an object of the present invention to provide a solid oxide fuel cell that can be operated stably without causing the possibility of occurrence of the above.

[0008]

Means for Solving the Problems To achieve the above object, the present invention provides: (1) A solid electrolyte layer having an anode layer and a cathode layer on both main surfaces is arranged on a cell substrate. A fuel cell body is formed by laminating a cell and a gas-impermeable separator having reaction gas flow grooves on both main surfaces, and introducing a fuel gas into one flow groove and leading it to the anode layer. In a solid oxide fuel cell in which an oxidizing gas is introduced into the other flow groove and guided to the cathode layer to generate power by an electrochemical reaction, (a) the cell substrate is embedded in the concave portion of the separator and laminated. .

(B) Alternatively, an anode layer, an electrolyte layer, and a cathode layer are formed on a cell substrate integrally joined to a separator in the above-described order or in the reverse order.
The cells are formed by forming them sequentially. (2) In a solid oxide fuel cell comprising a cell formed on a cell substrate embedded in a concave portion of one main surface of a separator and a plurality of stacked cells, (a) at least one of the above separators A concave notch is formed on one side, and a space formed by covering the concave portion on the side of the laminate formed by the continuation of the notch with a plate-like manifold structure is used as a manifold. It shall be connected to the above-mentioned manifold structure.

(B) Alternatively, a manifold structure having a concave cross section is provided on at least one side surface of the laminate, and a space surrounded by the side surface and the manifold structure is used as a manifold. To the manifold structure. (3) Alternatively, a cell in which a solid electrolyte layer having an anode layer and a cathode layer on both main surfaces is disposed on a cell substrate is provided on a gas-impermeable plate-like separator, and this is placed via a metal felt. In a solid electrolyte fuel cell having a plurality of stacked layers, a recess for embedding a cell substrate in one main surface of the separator is provided, and a reaction gas is introduced from one side of the separator to a bottom surface of the recess to introduce an in-plane. Forming a reaction gas flow groove consisting of a reciprocating flow path that is allowed to flow and then discharged from the same side, and an anode layer, an electrolyte layer, and a cathode are formed on the cell substrate embedded in the recess and integrally joined. The cells are formed by sequentially forming the layers in that order or vice versa, and one of the fuel gas and the oxidizing gas is passed between the metal felts and the other is passed through the reaction gas flow groove. Shed And Rukoto.

According to the above (1) (a), the side surface of the cell substrate is arranged closely to the wall surface of the concave portion of the separator.
Leakage of the reaction gas diffused into the inside of the cell substrate from the side surface of the cell substrate is prevented. Therefore, in this configuration, deterioration of battery characteristics due to gas cross leak due to gas leak from the side surface is avoided.

[0012] Further, according to the above (1) (b), not only the leakage of the reaction gas from the side surface of the cell substrate but also the leakage of the gas from the interface between the separator and the cell substrate can be suppressed. Is done. Therefore, deterioration of battery characteristics due to gas cross leak is avoided. Also,
As described in (a) and (b) of (2) above, a cell is formed on a cell substrate embedded in a recess on one main surface of a separator,
By stacking a plurality of these to form a laminate, and forming a manifold by arranging a manifold structure at the side end, the fuel gas and the oxidizing gas can leak from a side surface orthogonal to the flow direction. The gas is stably supplied from the manifold to each cell without deteriorating the battery characteristics due to the resulting gas cross leak.

According to the above (3), the fuel gas and the oxidant gas leak from a side surface perpendicular to the flow direction or a gas cross leak caused by a leak from an interface between the separator and the cell substrate. Therefore, the battery is stably supplied from the manifold to each cell without deteriorating the battery characteristics.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION

<Embodiment 1> FIGS. 1A and 1B are basic structural views of a solid oxide fuel cell according to Embodiment 1 of the present invention. FIG. 1A is an exploded perspective view, and FIG.
Is a sectional view. A basic unit is formed by laminating a separator 15, a cell 10, and a sealing material 17 having a shape as shown in FIG. 1A, and the fuel cell stack of this embodiment is configured by laminating a large number of the basic units.

The separator 15 has a fuel gas flow hole 18 and an oxidizing gas flow hole 19 formed in a Ni--Cr alloy plate, a fuel gas flow groove 20 on the anode side surface, and a fuel gas flow groove 20 on the opposite back surface. An oxidizing gas flow groove (not shown) arranged in a direction orthogonal to the gas flow groove 20 is formed, and YSZ (atmospheric pressure plasma spraying) is applied to the surface of the peripheral portion on the anode side surface. An insulating layer 16 formed by thermal spraying of yttria-stabilized zirconia is formed, and an anti-oxidation layer (not shown) made of lanthanum strontium manganite is formed on the surface on the cathode side. In addition, cell 10
Is formed by spraying NiO-YSZ powder by atmospheric pressure plasma spraying on a cell substrate 11 formed by pressing and vacuum sintering Ni-Cr alloy powder to form an anode layer 12 and a YSZ powder. To form an electrolyte layer 13, and further, lanthanum strontium manganite is flame-sprayed on the electrolyte layer 13 to form a cathode layer 14.

When the separator 15 thus prepared, the cell 10 and the sealing material 17 made of Pyrex glass are combined, a basic unit as shown in FIG. 1B is formed. At this time, the cells 10 are inserted and combined with each other in such a manner that the cell substrate 11 fits into the concave portion of the separator 15 where the fuel gas flow groove 20 is formed. In addition, cell 10
Are assembled so that the outer surface of the cathode layer 14 is flush with the outer surface of the sealing material 17. Therefore, the cathode layer 1
No. 4 is arranged facing the oxidizing gas passage groove of the separator 15 as a basic unit of the next layer.

In this configuration, the cell substrate 11 is
5, the side surface of the cell substrate 11 comes into close contact with the wall surface of the separator 15, so that the fuel gas diffused from the fuel gas flow groove 20 to the cell substrate 11 Leakage from the side surface is prevented, and since the structure is not a structure in which a sealing material is applied and sealed as in the conventional example, there is no deterioration and stable sealing performance can be obtained.

In this embodiment, the cell 10 in which the anode layer 12, the electrolyte layer 13, and the cathode layer 14 are sequentially formed on the cell substrate 11 is connected to the fuel gas passage groove 20 of the separator 15.
It is designed to be fitted in the recess on the side of
Not limited to this structure, the cathode layer, electrolyte layer,
It is needless to say that the same effect can be obtained even when a cell formed in the order of the anode layer is incorporated in a form in which the cell is fitted into the concave portion on the side where the oxidizing gas flow groove of the separator is formed. Is obvious without.

Embodiment 2 FIG. 2 is a perspective view showing a basic structure of a solid oxide fuel cell according to Embodiment 2 of the present invention.
In this configuration, the cell substrate 21 is joined to a separator 27 in which a fuel gas flow groove and an oxidizing gas flow groove are formed, and an anode layer 22, an anode height adjustment layer 25, an electrolyte layer 23, and a cathode layer are formed thereon. 24, a cell substrate / separator integrated cell produced by forming a cathode height adjustment layer 26.

FIG. 3 is a process explanatory view showing a method for producing a cell substrate / separator integrated cell having this configuration. Hereinafter, the manufacturing method will be described according to the division numbers in the drawings. (A) First, a fuel gas flow groove 28 and a concave portion for assembling a cell substrate are formed on the anode-side surface of a separator 27 made of a heat-resistant alloy, and an oxidant gas flow groove (not shown) is formed on the opposite surface.

(B) Next, the cell substrate 21 made of a Ni22Cr-based heat-resistant alloy is placed in the concave portion for mounting the cell substrate of the separator 27, and the temperature is raised in an inert gas atmosphere to integrate the separator 27 with the cell substrate 21. I do. (C) Next, the anode layer 22 is formed by spraying NiO-YSZ powder on the upper surface of the cell substrate 21 by atmospheric pressure plasma spraying.

(D) Next, a heat-resistant alloy powder of the same kind as the heat-resistant alloy used for forming the separator 27 is densely sprayed on the upper surface of the separator 27 on both side ends of the anode layer 22 to form a mixture with the anode layer 22. An anode height adjusting layer 25 for adjusting the height is formed. (E) Next, the anode layer 22, the anode height adjustment layer 2
YSZ is plasma-sprayed on the upper surface of 5 to form an electrolyte layer 23 made of a solid electrolyte body.

(F) Next, lanthanum strontium manganite is plasma-sprayed on the upper surface of the electrolyte layer 23 to form a cathode layer 24. (G) Next, a heat-resistant alloy powder of the same type as the heat-resistant alloy used for the separator 27 is densely sprayed on both end portions of the cathode layer 24 to form the cathode height adjustment layer 26.

(H) Then, lanthanum strontium manganite is plasma-sprayed on the surface of the surface of the separator 27 where the oxidizing gas flow grooves are formed, so that the heat-resistant protective film 3 is formed.
0 is formed. In the cell substrate / separator integrated cell formed by such a method, since the side surface of the cell substrate 21 is disposed in close contact with the wall surface of the separator 27, the cell substrate 2
Gas leakage can be prevented without forming a sealing material as in the conventional example on one side surface. In addition, the cell substrate 21
And the separator 27 are integrated, so that the cell substrate 2
A stable sealing performance can be obtained without disposing a conventional sealing material at the interface between the separator 1 and the separator 27. further,
In the present configuration, the contact resistance at the interface between the cell substrate 21 and the separator 27 is reduced due to the integrated configuration. In addition, since the cell substrate 21 is supported by the separator 27, the thickness of the cell substrate 21 can be reduced. Therefore,
The diffusion of the fuel gas becomes easy, and the fuel utilization can be improved.

<Embodiment 3> FIG. 4 is a perspective view showing a basic structure of a solid oxide fuel cell according to Embodiment 3 of the present invention.
FIG. 5 is a perspective view of a fuel cell stack formed by stacking the cell substrate / separator integrated cells of this configuration. The present embodiment shows an example of a cell substrate / separator integrated cell used for a fuel cell stack installed with the stacking direction arranged in the horizontal direction. In contrast, the separator was provided with flow holes corresponding to four manifolds of a fuel gas inlet manifold, a fuel gas outlet manifold, an oxidizing gas inlet manifold, and an oxidizing gas outlet manifold, respectively. Is characterized in that only two oxidizing gas flow holes 33 corresponding to the oxidizing gas inlet manifold and the oxidizing gas outlet manifold are provided in the separator 32 used in the first embodiment. That is, in this configuration, the separator 3 having the two oxidizing gas communication holes 33 is provided.
A plurality of fuel gas flow grooves 34 vertically arranged on one surface
Are formed in a plurality of oxidizing gas flow grooves 35 arranged in the horizontal direction on the opposite surface, and the substrate of the cell 31 is buried in a concave portion provided on the surface on which the fuel gas flow groove 34 is formed. And the separator 32 are integrated and combined. Therefore, also in the present configuration, gas leakage from the side surface of the cell substrate and gas leakage from the interface between the cell 31 and the separator 32 are effectively prevented. Needless to say, any of the methods described in Embodiment 1 and Embodiment 2 can be used as a method for manufacturing the cell 31.

As shown in FIG. 4, a concave portion 3 opening upward is formed at the upper end of the separator 32 of the integrated cell of the present structure.
6, a lower end is provided with a protruding portion 37 protruding downward. The integrated cells are stacked in the horizontal direction, and a recess 36 is formed in the fuel gas outlet manifold structure 38 as shown in FIG. By combining the protrusion 37 with the fuel gas inlet manifold structure 39, a fuel gas outlet manifold 40 and a fuel gas inlet manifold 41 are formed. Further, the two oxidant gas passage holes 33 shown in FIG.
Will form an oxidizing gas inlet manifold 42 and an oxidizing gas outlet manifold 43 with the lamination. The fuel gas outlet manifold structure 38 and the fuel gas inlet manifold structure 39 are formed by inserting a sealing material into the concave portion of the integrated cell, and then fitting the protruding portions provided on the fuel gas outlet manifold structure 38 into the fuel cell. After the sealing material is inserted into the concave portion provided in the inlet manifold structure 39, the protrusion of the integrated cell is fitted into the integrated cell to be incorporated into the integrated cell. When the temperature rises with the power generation operation, the inserted sealing material melts and stays on the bottom surface of the concave portion, so that excellent sealing performance can be obtained.

<Embodiment 4> FIG. 6 is a perspective view showing a basic structure of a solid oxide fuel cell according to Embodiment 4 of the present invention.
FIG. 7 is an exploded perspective view of a main part of the present configuration. In this configuration, the cell substrate 46 is integrated into a recess provided adjacent to the plurality of oxidizing gas flow grooves 45 formed on one surface of the flat separator 44, and the electrolyte layer 46 and the anode are formed on the outer surface thereof. The fuel cell stack is formed by forming the layer 48 to form an integrated cell and alternately stacking it with Ni felt forming the fuel gas passage. That is, as shown in FIG. 7, an oxidizing gas flow groove 45 formed of a reciprocating flow path is formed on one surface of the separator 44, and lanthanum strontium manganite is sprayed on this surface to form the oxidizing gas flow groove 45. A lanthanum strontium manganite porous body is arranged in the recess provided adjacently,
The temperature is raised in the air and the firing is performed integrally. Then, after removing the oxide film formed on the anode side surface of the separator 44, that is, the opposite surface, by sandblasting,
The electrolyte layer 4 was prepared in the same manner as described in Example 2.
7. Form the anode layer 48 to obtain a cell substrate / separator integrated cell. In this configuration, the oxidant gas is supplied and discharged from the same surface of the separator 44, and the fuel gas is supplied through Ni felt interposed between the cells.

Also in this configuration, since the cell substrate and the separator are integrally formed, gas leakage from the side surface of the cell substrate 46 and gas leakage from the interface between the cell substrate 46 and the separator 44 are effective. Is prevented.

[0029]

As described above, in the present invention, (1) the solid oxide fuel cell is configured as described in claim 1, so that gas leakage from the side surface of the cell substrate is prevented. As a result, a solid electrolyte fuel cell that can be operated stably without causing damage due to cross leak between the fuel gas and the oxidizing gas can be obtained.

(2) When the solid oxide fuel cell is configured as described in claim 2, gas leakage from the interface between the cell substrate and the separator is further prevented, and the cell substrate is made thin. Therefore, there is no risk of damage due to gas cross leak, and a solid oxide fuel cell with high fuel utilization can be obtained. (3) When the solid oxide fuel cell is configured as described in claim 3 or 4, damage due to gas leakage from the side surface of the cell substrate is prevented, and the reaction is more stable than the manifold provided at the side end. Since the gas is supplied, a solid oxide fuel cell that can be operated stably and can be easily combined can be obtained.

(4) When the solid oxide fuel cell is configured as described in claim 5, gas leakage from the side surface of the cell substrate and gas leakage from the interface between the cell substrate and the separator are prevented. As a result, a stable supply of the reaction gas is provided from the manifold provided at the side end, and a solid oxide fuel cell that can operate stably is obtained.

[Brief description of the drawings]

FIG. 1 is a basic configuration diagram of a solid oxide fuel cell according to a first embodiment of the present invention, in which (a) is an exploded perspective view and (b) is a cross-sectional view.

FIG. 2 is a perspective view showing a basic configuration of a solid oxide fuel cell according to Embodiment 2 of the present invention.

FIG. 3 is a process explanatory view showing a method for manufacturing an integrated cell having the structure of Example 2.

FIG. 4 is a perspective view showing a basic configuration of a solid oxide fuel cell according to Embodiment 3 of the present invention.

FIG. 5 is a perspective view of a fuel cell stack formed by stacking integrated cells having the configuration of Example 3.

FIG. 6 is a perspective view showing a basic configuration of a solid oxide fuel cell according to Embodiment 4 of the present invention.

FIG. 7 is an exploded perspective view of a main part of the configuration of the fourth embodiment.

FIG. 8 is an exploded perspective view showing a basic structure of a conventional solid electrolyte fuel cell of a flat support membrane type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Cell 11 Cell substrate 12 Anode layer 13 Electrolyte layer 14 Cathode layer 15 Separator 16 Insulation layer 17 Seal material 18 Fuel gas flow hole 19 Oxidant gas flow hole 20 Fuel gas flow groove 21 Cell substrate 22 Anode layer 23 Electrolyte layer Reference Signs List 24 cathode layer 25 anode height adjustment layer 26 cathode height adjustment layer 27 separator 28 fuel gas passage groove 29 oxidant gas passage groove 30 acid-resistant protective film 31 cell 32 separator 33 oxidant gas passage hole 34 fuel gas passage Flow groove 35 Oxidant gas flow groove 36 Recess 37 Projection 38 Fuel gas outlet manifold structure 39 Fuel gas inlet manifold structure 40 Fuel gas outlet manifold 41 Fuel gas inlet manifold 42 Oxidizer gas inlet manifold 43 Oxidizer gas outlet Manifold 44 Separator 45 Agent gas passage groove 46 cell substrate 47 electrolyte layer 48 anode layer 49 Ni felt

Claims (5)

[Claims] 1. A cell having a solid electrolyte layer having an anode layer and a cathode layer on both main surfaces on a cell substrate, and a gas-impermeable separator having reaction gas flow grooves on both main surfaces. Are laminated to form a fuel cell main body, a fuel gas is introduced into a reaction gas flow groove formed on one surface and led to the anode layer, and a reaction gas flow groove formed on the other surface is formed. What is claimed is: 1. A solid oxide fuel cell comprising: a cell substrate embedded in a recess of a separator and stacked by introducing an oxidizing gas to a cathode layer to generate electricity by an electrochemical reaction. 2. A cell having a solid electrolyte layer having an anode layer and a cathode layer on both main surfaces on a cell substrate, and a gas-impermeable separator having reaction gas flow grooves on both main surfaces. Are laminated to form a fuel cell main body, a fuel gas is introduced into a reaction gas flow groove formed on one surface and led to the anode layer, and a reaction gas flow groove formed on the other surface is formed. In a solid oxide fuel cell that generates an electrochemical reaction by introducing an oxidizing gas to a cathode layer by introducing an oxidizing gas, the cell is embedded in a concave portion of a separator and is integrally bonded on a cell substrate, an anode layer, A solid oxide fuel cell comprising an electrolyte layer and a cathode layer formed sequentially in that order or in the reverse order. 3. A solid oxide fuel cell comprising a cell formed on a cell substrate buried in a concave portion on one main surface of a separator and comprising a plurality of stacked cells, wherein at least one side of the separator is A concave notch portion is formed, and a space in which a concave portion on the side of the laminate formed by the continuation of the notch portion is covered with a plate-like manifold structure is used as a manifold, and each of the separators is the manifold. A solid oxide fuel cell characterized by being bonded to a structure. 4. A solid oxide fuel cell comprising a cell formed on a cell substrate buried in a concave portion on one main surface of a separator and comprising a plurality of stacked cells. A solid structure characterized in that a manifold structure having a concave cross-sectional shape is provided on one side surface and a space surrounded by the side surface and the manifold structure is a manifold, and the separators are respectively coupled to the manifold structure. Electrolyte fuel cell. 5. A cell in which a solid electrolyte layer having an anode layer and a cathode layer on both main surfaces is disposed on a cell substrate, provided on a gas-impermeable flat plate separator, and this is placed via a metal felt. In a solid electrolyte fuel cell having a plurality of stacked layers, a main surface of the separator has a recess for embedding the cell substrate, and a reaction gas is introduced from one side of the separator to a bottom surface of the recess. And a reaction gas flow groove comprising a reciprocating flow path for discharging from the same side after flowing through the surface is formed on the cell substrate embedded in the recess and integrally joined. , An anode layer, an electrolyte layer, and a cathode layer, which are sequentially formed in that order or the reverse order. One of a fuel gas and an oxidant gas is placed between the metal felts, and the other is the reaction gas. Through A solid oxide fuel cell characterized by flowing through a flow channel.