JP2000294267A - Solid electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid electrolyte fuel cell having a remarkably low cell stack in comparison with a solid electrolyte fuel cell having a conventional separator structure, laminated layers with high density and a thin solid electrolyte layer and capable of excellently reducing an ohm loss. SOLUTION: This solid electrolyte fuel cell is formed by a power generating layer with a three layer structure comprising a fuel cell layer 11 provided on one surface of a solid electrolyte layer 10 having ion conductivity and an oxygen electrode layer provided on other surface, a conduction layer 14b with gas conductivity provided so as to sandwich the power generating layer and an isolation layer having electric conductivity although practically having no gas permeability.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solid electrolyte,
The present invention relates to a solid oxide fuel cell that converts chemical energy of a chemical substance into electrical energy by an electrochemical reaction, and more particularly to a solid oxide fuel cell excellent in reducing the height of a cell stack.

[0002]

2. Description of the Related Art The structure of a solid oxide fuel cell is typically of two types, a cylindrical type and a flat type. Of these, the flat type is
Since the ion conduction distance can be shortened as compared with the cylindrical type, high efficiency power generation is expected.

FIG. 1 shows a typical structure of a plate-type solid oxide fuel cell. A flat solid electrolyte fuel cell has a flat solid electrolyte 1 on one surface of a fuel electrode (fuel electrode) 2.
However, an oxygen electrode (oxygen electrode) 3 is disposed on the other surface, and the gas-impermeable separators 4 and 5 having electrical conductivity partition the power generation layer having the three-layer structure.

The above structure is treated as a single cell (single cell), but the area of the single cell cannot be made too large due to problems such as material strength. Therefore, in order to obtain an output, it is common to stack single cells in a series direction. This stacked battery is called a stack. In order to increase the power generation capacity of a flat solid electrolyte fuel cell, it is important to develop a single cell multilayer technology.

[0005] As can be seen from FIG.
5 requires a passage for passing fuel gas and air. On the other hand, the separator and the solid electrolyte are also required to have mechanical strength enough to withstand the load applied during stacking of the single cells. The separator and the solid electrolyte need to have a thickness in the laminating direction in order to secure the mechanical strength that can withstand the stack in addition to the provision of the flow passage. In addition, as a result of increasing the thickness of the solid electrolyte or the separator in order to secure mechanical strength, there is a problem that the ohmic loss of the cell increases. In order to reduce the height of the cell stack and improve the battery performance, it is important to reduce the thickness of the separator and the solid electrolyte.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a solid oxide fuel cell which is excellent in reducing the height of the cell stack and reducing the ohmic loss of the cell. More specifically, it is an object of the present invention to provide a solid electrolyte fuel cell that has achieved a remarkable reduction in height and a high-density lamination as compared with a solid electrolyte fuel cell having a conventional separator structure.

[0007]

According to the first aspect of the present invention, there is provided an upper isolation layer (15) having substantially no gas permeability but having electronic conductivity formed on the uppermost layer of a solid oxide fuel cell.
having a) a E _U and a E _L lower isolating layer (15a) that substantially no has an electron conductivity gas permeability are formed in the lowermost layer of the solid electrolyte type fuel cell, the ionic conductivity A power generation layer having a three-layer structure formed of a solid electrolyte layer (10), a fuel electrode layer (11) provided on one surface of the solid electrolyte layer, and an air electrode layer (12) provided on the other surface. (13a) is defined as W _a and the air electrode layer (1) provided on the one surface side of the solid electrolyte layer (10) having ionic conductivity.
2) and the fuel electrode layer (1) provided on the other surface side.
The power generation layer (13b) having a three-layer structure formed from
_The gist of the present invention is to provide a solid oxide fuel cell comprising a stack in which _b and a gas-permeable flow-through layer (14) formed so as to sandwich the power generation layer (13) are stacked in accordance with a predetermined arrangement. I do. The present invention will be described below with reference to structural examples shown in FIGS.

FIGS. 3 to 6 are explanatory views showing an example of the power generation layer 13 having a three-layer structure according to the present invention. The fuel electrode layer 11 is provided on one surface of the solid electrolyte layer 10, the air electrode layer 12 is provided on the other surface, and the power generation layer 13 having a three-layer structure is formed. Passing Here, for convenience of explanation, facing the power generation layer of the structure of Figures 3 and 4 W _a (13a), the power generation layer of the structure of FIGS. 5 and 6 W _{b (13b),} the fuel electrode layer Nagareso P and 14a, but a flowing layer P and 14b facing the air electrode layer, actually the opposite configuration (e.g., W _a is 13b, W
_b may be 13a). In short, W _a and _{W b}
What is necessary is that the formation surfaces of the fuel electrode layer 11 and the air electrode layer 12 with respect to the solid electrolyte layer 10 are opposite. Therefore, E
Even in a configuration in which the air electrode layer side is opposed to the u side via the flow layer P, it is sufficient if the air electrode layer side is laminated according to a predetermined arrangement. This is the same in the following description.

FIG. 7 shows a single cell (16) of the fuel cell of the present invention.
It is explanatory drawing which shows an example of a). Gas-permeable flow layers 14a and 14b are provided on both surfaces of the three-layered power generation layer (here, 13a is used for convenience), and gas flow is substantially provided on both surfaces of the flow layers 14a and 14b. Isolation layers 15a and 15b, which do not have but have electronic conductivity, are provided to form a single cell 16a. FIG. 8 shows a single cell (16b) of a fuel cell when the power generation layer is 13b.
It is exactly the same as 16a except that the surface on which each electrode is formed is opposite to 16a.

As described above, according to the present invention, a flow passage for passing a fuel gas or air which is essential for a solid oxide fuel cell is not provided as a simple space, but is formed as a flow layer having gas permeability. I do. In a gas passage in a normal fuel cell, a space is provided in which a groove or the like is provided in a separator or an electrode layer, or a support layer is provided between a separator and an electrode layer.

By forming the “flow channel” as a “flow layer” instead of a mere space, the effect of increasing the mechanical strength of the stacked cell is exhibited. By using the flow layer as a reinforcing material, the thickness of the solid electrolyte layer can be further reduced. With such a configuration, it is possible to realize a drastic reduction in height, a high-density lamination, and a low ohmic loss due to a reduction in the thickness of the solid electrolyte layer, as compared with a conventional solid oxide fuel cell.

FIGS. 9 to 11 show the general formula A (n) of the present invention.
= 1) is an explanatory view showing an example of a single cell stack (17). The stack top isolation layer E _U (15a)
, Lower isolation layer E _L (15b), flow layer P (14a and 14b), power generation layers Wa (13a) and Wb (13b).
Are laminated according to the arrangement of the general formula A. By stacking single cells in multiple layers, the strength of the entire stack is increased, so that the thickness of the solid electrolyte layer can be reduced. As a result, ohmic loss of the battery can be reduced.

FIGS. 12 to 14 show the general formula B of the present invention.
It is explanatory drawing which shows an example of the stack (19) of the single cell of (n = 1). The stack top isolation layer E _U (15
a), the lower isolation layer E _L (15b), and the flow layer P (14
a and 14b), the power generation layers Wa (13a) and Wb (13
b) are laminated according to the arrangement of general formula B. By stacking single cells in multiple layers, the strength of the entire stack is increased, so that the thickness of the solid electrolyte layer can be reduced. As a result, ohmic loss of the battery can be reduced.

FIG. 10 is a sectional view of a cell stack (17) of the general formula A (n = 1) of the present invention, and FIG. 13 is a sectional view of a cell stack (19) of a general formula B (n = 1). Show. The fuel gas flows into the flow layer (14a) on the fuel electrode layer (11) side formed on each power generation layer (Wa and Wb), and the flow layer P (14b) on the air electrode layer (12) side. Air is swept away.

In order to operate these cell stacks (17 and 19) as fuel cells, it is necessary to separate the fuel gas inlet and outlet from the air inlet and outlet as shown in FIGS. That is, it is necessary to close the air inflow / outflow port on the fuel gas inflow / outflow side, and to close the fuel gas inflow / outflow port on the air inflow / outflow side. This is because, unless the fuel gas inflow port and the air inflow port are separated, there is no gas concentration difference between the electrodes, and no electromotive force is generated. As a method of separating and closing, for example, a method of sealing the exposed surface of the power generation layer with a sealing member can be used. As a sealing member, a glass seal can be used for a battery that operates at a high temperature, and a resin seal can be used for a battery that operates at a low temperature.

The solid electrolyte fuel cell of the present invention, all of the fuel electrode layer is electrically connected to one of E _U or E _L in a state of being electrically short-circuited, and, all of the air electrode layer It is electrically electrically connected to one of the shorted state different from the person who the fuel electrode layer is connected E _L or E _U, to form a parallel connection of a so-called single cell. By configuring such a parallel connection, it is possible to increase the capacity of the battery. The output can be increased by further connecting the solid electrolyte fuel cells connected in parallel in series. Although the parallel connection is basically performed by providing external terminals, the connection can be made inside or on the surface of the cell stack by applying a ceramic multilayering technique used in the field of ceramic packages.

For the solid electrolyte layer of the present invention, known ceramic solid electrolytes and polymer solid electrolytes can be used. As in the invention of claim 4, any of an oxide ion conductive solid electrolyte and a proton conductive solid electrolyte can be used. Since the overall strength of the cell of the present invention can be ensured by multi-layering, the thickness of the solid electrolyte layer can be set smaller than before. In addition, since the ohmic loss can be reduced by reducing the thickness of the solid electrolyte, an effect of improving the performance of the battery can be obtained.

When using a ceramic solid electrolyte,
As in the invention of claim 2, said _{E U, E L, W a} , W b, P
Is desirably made of a ceramic-based sintered body integrally formed by simultaneous firing. The material of each member is formed into a green sheet using a known technique such as a doctor blade method, and is integrally laminated by thermocompression bonding or the like. After removing the organic binder in a heating furnace, the cell stack is completely integrated by simultaneous firing. By using the co-firing technique, it is possible to achieve both reduction in the thickness of the cell stack and improvement in the strength. The electrode material may be formed into a green sheet and laminated. Alternatively, the paste may be formed into a paste, printed on a solid electrolyte green sheet using a known screen printing technique, and then laminated and fired simultaneously. .

During firing, firing can be performed while applying pressure to the cell stack within a range that does not impair the flowability of the flow layer. A method of baking while applying pressure to a plate made of a material having no reactivity with the cell stack is used. By such pressure baking, the flatness of the cell stack can be improved. By suppressing the occurrence of warpage of the cell stack, stress concentration or the like applied to the warped portion of the cell during stacking or operation of the battery can be reduced.

Ceramic oxide ion conductive solid electrolyte
The resolution is Y_TwoO_Three-ZrO_TwoSo-called YSZ system
(Specific example; (ZrO_Two)_0.92(Y_TwoO_Three)_0.08), (L
a, Sr) (Ga, Mg) O_ThreeSo-called LaGaO_Three
System (specific examples; La_0.9Sr_0.1Ga_0.8Mg_0.2O_Three), S
m_TwoO_Three-CeO_Two(Specific examples; (SmO_1.5) (Ce
O_Two) _0.9), Gd_TwoO_Three-CeO_TwoSystem, Y_TwoO_Three-CeO
_TwoSystem, Sc_TwoO_Three-ZrO_TwoA system or the like can be used.

Ceramic-based proton conductive solid electrolyte
As, for example, SrCe_0.95Yb _0.05O_3−σUse
Can be. In addition, mixed ion conductive ceramics
As the conductive solid electrolyte, for example, BaCe_0.8Y_0.2O
_3−σOr a transition metal-added LaGaO_ThreeSystem material
(La, Sr) (Ga, Ni) O_ThreeMixed ionic conductivity such as
A body or the like can be used.

When a polymer-based solid electrolyte is used,
The above E processed into a sheet shape_U, E_L, W _a, W_b, P thermocompression
It is preferable to use a known lamination method using a known technique such as
No. By stacking multiple layers, the cell stack can be made thinner and stronger.
It is possible to achieve both improvement in degree.

As the polymer-based solid electrolyte, an ion exchange resin, particularly a cation exchange resin can be used. For example, perfluorocarbon sulfonic acid (PFS)
A) A proton conductive polymer such as a fluororesin type sulfonic acid polymer such as an ion exchange membrane can be used.
As a specific example, Nafion (registered trademark, Du Po)
nt) and a DOW film (commonly known as Dow Chemical)
l company).

Known materials can be used as the fuel electrode of the present invention. In ceramics, Ni-YS
Z, Ru-YSZ, or the like can be used. In the polymer system, an electrode in which a platinum catalyst is supported on carbon fine particles can be used.

As the air electrode of the present invention, known materials can be used. In the ceramic system, (La, S
r) Lanthanum strontium manganate such as MnO ₃ and (La, Sr) (Mn, Co) O ₃ (so-called LSM
(La), (La, Sr) (Fe, Co) O _{3, and the} like. In the polymer system, an electrode in which a platinum catalyst is supported on carbon fine particles can be used.

It is desirable that the electrode layer forms a three-phase interface between the gas phase, the electrode, and the electrolyte at the interface with the solid electrolyte layer. The "three-phase interface (T
As shown in FIG. 2, “phase phase boundary” means a phase (9) composed of an electrode (6), an electrolyte (7), and a gas phase (8). When the three-phase interface length per unit area in the porous electrode decreases, the overvoltage increases. Therefore, it is desirable to select a stable electrode material having a small change in the three-phase interface length with time.

The flow layer according to the present invention is preferably formed by a porous body having communicating pores, as in the invention of claim 4. This is because the gas flow layer needs to have gas flowability for passing fuel gas and air. In the cell of the present invention, since the cell can be given overall strength by multi-layering, there is no problem in terms of strength even if a flow layer made of a porous body is interposed.

Known materials can be used as the flow layer of the present invention. In the case of a ceramic material, the condition is that it is easy to co-fire with the solid electrolyte. Y ₂ O ₃ -ZrO
_When a so-called YSZ system such as ₂ is used for the solid electrolyte,
It is desirable to use a porous body YSZ. Basically, a porous body of the same material is ideal, but if the difference in sintering behavior is not extreme, the warpage of the cell stack can be prevented by using the above-described pressure firing method.

In order to produce a porous body having interconnected pores, resin beads or the like may be added to the slurry when producing a green sheet for the flow layer. Since such resin beads are removed together with the organic binder when the resin is removed, pores communicating with the sintered body can be formed.

In the case of a polymer, it is determined in consideration of economy, weight reduction, moldability and heat resistance. Specifically, PTFE
(Polytetrafluoroethylene), a porous body of fluororesin such as PVDF (polyvinylidene fluoride), a porous body of PE (polyethylene) resin such as HDPE (high-density polyethylene), LDPE (low-density polyethylene), etc. be able to. Depending on the operating conditions of the battery, a porous body of polyethylene terephthalate (PET) resin, polyimide (P)
I) Porous resin, polyether sulfone (PES)
Porous resin, polyphenylene sulfide (PPS)
Resin porous body, polyetherimide (PEI) resin porous body, polyetheretherketone (PEEK) resin porous body, aromatic polyester (LCP) resin porous body, zindiotactic polystyrene (SPS) resin porous body Body, fluorine-polyethersulfone (PTFE-
A porous body of (PPS) alloy resin or the like can also be used.

The invention of claim 3, the _{E U, E L, E M} ,
The gist of the present invention is a solid oxide fuel cell comprising a ceramic-based sintered body in which W _a and P ′ are laminated according to the arrangement shown in the general formula C and integrally formed by simultaneous firing. According to the first aspect of the present invention, each single cell of the laminate is connected in parallel. However, the present invention relates to an intermediate isolation layer (15a) E _M having substantially no gas permeability but having electronic conductivity. Each single cell of the stacked body is connected in series using P 'as a flow layer (14) having both conductivity and gas permeability.

FIGS. 15 to 17 show the general formula C of the present invention.
It is explanatory drawing which shows an example of the stack (21) of the single cell of (n = 1). The stack top isolation layer E _U (15
and a), the lower isolation layer E _L (15b), isolation layer _E M (2
3), the flow layer P ′ (14a and 14b), and the power generation layer W
a (13a) and Wb (13b) are laminated according to the arrangement of the general formula C. By stacking single cells in multiple layers, the strength of the entire stack is increased, so that the thickness of the solid electrolyte layer can be reduced. As a result, ohmic loss of the battery can be reduced.

FIG. 16 is a sectional view of the cell stack (21) of the general formula C (n = 1) of the present invention. The fuel gas flows into the flow layer (14a) on the fuel electrode layer (11) side formed on each power generation layer (Wa and Wb), and the flow layer P (14b) on the air electrode layer (12) side. Air is swept away.

In order to operate this cell stack (21) as a fuel cell, it is necessary to separate the fuel gas inlet and outlet from the air inlet and outlet as shown in FIG. That is, it is necessary to close the air inflow / outflow port on the fuel gas inflow / outflow side, and to close the fuel gas inflow / outflow port on the air inflow / outflow side. This is because, unless the fuel gas inflow port and the air inflow port are separated, there is no gas concentration difference between the electrodes, and no electromotive force is generated. As a method of separating and closing, for example, a method of sealing the exposed surface of the power generation layer with a sealing member can be used. As a sealing member, a glass seal or the like can be used.

As shown in FIGS. 15 and 16, the solid electrolyte fuel cell according to the present invention has a power generation layer (13a) and a flow through layer P '.
(14a and 14b) and the intermediate isolation layer E
It is configured to be stacked via _L (23). Since the flowing layer P 'and the intermediate isolating layer E _L has both electron conductivity, without providing the external terminal as in the invention of claim 1, the cell stack can be connected in series.

[0036] The intermediate isolation layer E _L, it is required to combine the denseness and electronic conductivity that is substantially permeable to gases. Considering the co-firing with the solid electrolyte,
It is desirable to use a dense body of the same material as the above-mentioned fuel electrode or air electrode. Because one side of the intermediate isolating layer E _L are constantly exposed to the air, better to use the same material as the air electrode is preferred over the stability of the battery.

The flow layer P 'is required to have both the communicating pores through which gas can flow and the electron conductivity. It is desirable to use a dense body of the same material as the above-mentioned fuel electrode or air electrode in consideration of matching of simultaneous firing with a solid electrolyte. It is preferable to use a porous body made of the same material as the fuel electrode on the side (14a) through which the fuel flows, from the viewpoint of firing matching. Since the side (14b) through which air flows is always exposed to air, it is preferable to use the same material as the air electrode from the viewpoint of battery stability. The material of the intermediate isolating layer E _M and flowing layer P 'other portions, the same as the invention of claim 1 can be used.

It is desirable that the electrode layer forms a three-phase interface between the gas phase, the electrode and the electrolyte at the interface with the solid electrolyte layer. The "three-phase interface (T
As shown in FIG. 2, “phase phase boundary” means a phase (9) composed of an electrode (6), an electrolyte (7), and a gas phase (8). When the three-phase interface length per unit area in the porous electrode decreases, the overvoltage increases. Therefore, it is desirable to select a stable electrode material having a small change in the three-phase interface length with time.

[0039]

EXAMPLE 10 parts by weight of polyvinyl butyral and 25 parts by weight of a toluene-isopropyl alcohol solution were added to 65 parts by weight of YSZ powder having a composition ratio of (ZrO ₂ ) _0.92 (Y ₂ O ₃ ) _0.08 and mixed by a ball mill. Adjust the slurry for the doctor blade. The preparation of the YSZ solid electrolyte green sheet having a thickness of 50 μm is completed by the dokuda blade method.

Next, YSZ4 having the same composition as the solid electrolyte
60 parts by weight of Ni is added to 0 parts by weight and mixed. To 65 parts by weight of the mixed powder, 10 parts by weight of polyvinyl butyral and 25 parts by weight of a toluene-isopropyl alcohol solution are added and mixed by a ball mill to prepare a slurry for a doctor blade. 250 thickness by dokuda blade method
Preparation of the μm YSZ isolation layer green sheet is completed.

Next, YSZ4 having the same composition as the solid electrolyte
60 parts by weight of Ni is added to 0 parts by weight and mixed. To 70 parts by weight of the mixed powder, 10 parts by weight of ethyl cellulose and 20 parts by weight of butyl carbitol acetate are added and kneaded by a three-roll mill to complete the preparation of the fuel electrode paste.

Then, 10 parts by weight of ethyl cellulose and 20 parts by weight of butyl carbitol acetate were added to 70 parts by weight of a lanthanum strontium manganate (hereinafter referred to as LSM) powder having a composition ratio of La _0.87 Sr _0.10 MnO ₃ , and 3 The mixture is kneaded with a roll mill to complete the preparation of the air electrode paste.

To 60 parts by weight of YSZ powder having the same composition as the solid electrolyte, 10 parts by weight of polyvinyl butyral, 25 parts by weight of a toluene-isopropyl alcohol solution, and 5 parts by weight of acrylic resin beads were added and mixed by a ball mill. Adjust the slurry. The preparation of a 400 μm thick YSZ flow-through layer green sheet is completed by the dokuda blade method.

A paste for a fuel electrode is applied to one surface of the YSZ solid electrolyte green sheet by a screen printing method and dried. The air electrode paste is applied to the other surface of the YSZ solid electrolyte green sheet by a screen printing method and dried to complete the adjustment of the power generation layer green sheet. .

According to the layer structure and arrangement shown in FIG.
The power generation layer green sheet, the YSZ conduction layer green sheet, and the isolation layer green sheet are sequentially pressed and laminated. External terminals are formed by printing with platinum paste. After removing the organic binder in a degreasing furnace, baking is performed at 1500 ° C. A glass paste is printed on the obtained sintered body in a pattern for separating the fuel electrode and the air electrode, and baked at 900 ° C. And platinum wire bonded to the external terminal, E _U by shorting all of the fuel electrode layer
Connected to, then, by shorting all of the air electrode layer E _L
To complete the solid oxide fuel cell.

[0046]

According to the present invention, it is possible to provide a solid oxide fuel cell excellent in reducing the height of the cell stack and reducing the ohmic loss of the cell. More specifically, it is possible to provide a solid oxide fuel cell that has achieved a remarkable reduction in height and high-density stacking as compared with a solid oxide fuel cell having a conventional separator structure. When a ceramic member is used, it can be integrally formed by simultaneous firing, so that multilayering and thinning can be easily realized.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a conventional flat panel fuel cell.

FIG. 2 is an explanatory diagram of a three-phase interface formed at an interface between a solid electrolyte and an electrode.

FIG. 3 is an explanatory diagram of a power generation layer in which a fuel electrode layer is formed on an upper isolation layer side.

FIG. 4 is an explanatory view showing a cross section of a power generation layer in which a fuel electrode layer is formed on the upper isolation layer side.

FIG. 5 is an explanatory diagram of a power generation layer in which a fuel electrode layer is formed on a lower isolation layer side.

FIG. 6 is an explanatory view showing a cross section of a power generation layer in which a fuel electrode layer is formed on a lower isolation layer side.

FIG. 7 is an explanatory view of a single cell using a power generation layer in which a fuel electrode layer is formed on an upper isolation layer side.

FIG. 8 is an explanatory view of a single cell using a power generation layer in which a fuel electrode layer is formed on a lower isolation layer side.

FIG. 9 is an explanatory diagram of a cell stack of the general formula A (n = 1).

FIG. 10 is an explanatory diagram of a cross section of a cell stack of the general formula A (n = 1).

FIG. 11 is an explanatory diagram of a solid oxide fuel cell of the general formula A (n = 1).

FIG. 12 is an explanatory diagram of a cell stack of general formula B (n = 1).

FIG. 13 is an explanatory diagram of a cross section of a cell stack of the general formula B (n = 1).

FIG. 14 is an explanatory diagram of a solid oxide fuel cell of the general formula B (n = 1).

FIG. 15 is an explanatory diagram of a cell stack of the general formula C (n = 1).

FIG. 16 is an explanatory diagram of a cross section of a cell stack of the general formula C (n = 1).

FIG. 17 is an explanatory diagram of a solid oxide fuel cell represented by the general formula C (n = 1).

[Explanation of symbols]

10 Solid electrolyte layer. 11 Fuel electrode layer. 12 Air electrode layer. 13a Power generation layer in which the fuel electrode layer is formed on the upper isolation layer side. 13b A power generation layer in which the fuel electrode layer is formed on the lower isolation layer side. 14a Fuel flow layer. 14b Air flow layer. 17 Cell stack of general formula A (n = 1). 19 Cell stack of general formula B (n = 1). 21 Cell stack of general formula C (n = 1).

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Ryuji Inoue 14-18, Takatsuji-cho, Mizuho-ku, Nagoya-shi, Aichi F-term (in reference) 5H026 AA06 BB01 CV08 EE11 EE13

Claims (6)

[Claims] 1. A top isolation layer substantially free has an electron conductivity gas permeability are formed in the uppermost layer of the solid electrolyte type fuel cell (15a) E _U, the bottom layer of the solid oxide fuel cell a lower isolation layer substantially free has an electron conductivity (15b) to E _L, a solid electrolyte layer having ionic conductivity (10) the gas permeability is formed, provided on one surface of the solid electrolyte layer A power generation layer (13a) having a three-layer structure formed from the fuel electrode layer (11) provided and the air electrode layer (12) provided on the other surface is formed by a solid electrolyte layer (W _a ) having ion conductivity. air electrode layer provided on the one side of 10) and (12), the power generation layer of the three-layer structure formed from the above other fuel electrode layer provided on the surface side of (11) to (13b) W _b The gas permeability formed so as to sandwich the power generation layer (13) When flowing layer (14) and is P, the _{E U, E L, W a} , W b, P is composed of a stack are stacked in accordance with the sequence shown in the following formula A or formula B Rutotomoni is electrically connected to one of every E fuel electrode layer is in a state of being electrically short-circuited _U or E _L, and the above in a state where all of the air electrode layer is electrically shorted solid oxide fuel cell, wherein a fuel electrode layer is electrically connected to one of the direction different from E _L or E _U connected. Formula _{A; E U - (P-} W a -P-W b) n -P-W a -P-E L (n is 0 or a natural number) In formula _{B; E U - (P-} W a - P−W _b ) _n −P−E _L (n is a natural number of 1 or more) Wherein said _{E U, E L, W a} , W b, the solid oxide fuel as claimed in claim 1 in which P is characterized by comprising a sintered body of ceramic mainly formed integrally by co-firing battery. Wherein the upper isolating layer substantially free has an electron conductivity gas permeability are formed in the uppermost layer of the solid electrolyte type fuel cell (15a) E _U, the bottom layer of the solid oxide fuel cell is substantially free of substantially free E is lower isolation layer having an electron conductivity (15a) _L, the gas permeability is laminated on the inner layer of the solid oxide fuel cell gas permeable formed An intermediate isolation layer having electronic conductivity (1
5a) is a solid electrolyte layer (10) having E _M and ion conductivity, a fuel electrode layer (11) provided on one surface of the solid electrolyte layer, and an air electrode layer (12) provided on the other surface. The power generation layer (13a) having the three-layer structure formed by the above is W _a , and the flow layer (14) formed so as to sandwich the power generation layer (13a) and having both electron conductivity and gas permeability is P a. 'in case of the above _{E U, E L, E M} , W a, P' be formed of a sintered body of ceramic mainly formed integrally by co-firing are stacked according to sequence is shown in the following formula C A solid oxide fuel cell comprising: Formula _{C; E U - (P'-} W a -P'-E M) n -P'-W a -P'-E L (n is 0 or a natural number) 4. The solid oxide fuel cell according to claim 1, wherein said solid electrolyte layer is one of an oxide ion conductor and a proton conductor. 5. The solid oxide fuel cell according to claim 1, wherein the flow layer is formed of a porous body having communicating pores. 6. The fuel electrode layer and the air electrode layer form a three-phase interface between a gas phase, an electrode, and an electrolyte at an interface with the solid electrolyte layer. 5. A solid oxide fuel cell according to