JP2002203588A - Solid oxide type fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To attain miniaturization of a fuel cell by making a pre-heater for fuel gas and the like, unnecessary. SOLUTION: A total of n pieces of separator 12 is sandwiched for every one, respectively, between a fuel electrode layer 11b of an i-th power generation cell among (n+1) pieces of generation cell, and an oxidizer electrode layer 11c of an (i+1)-th power generation cell. A porous fuel electrode collector 13 is sandwiched between the fuel electrode layer of the i-th power generation cells 11 and the j-th separator, and a porous oxidizer electrode collector 14 is sandwiched between an oxidizer electrode layer of the (i+1)-th power generation cell and the j-th separator. A 1st end plate 21 is The laminated to a 1st oxidizer electrode layer of the 1st power generation cell, and a 2nd end plate 22 is laminated to the fuel electrode layer of the (n+1)-th power generation cell. A fuel supplying passage 16 and an oxidizer supplying passage 17 are formed winding their ways in each separator, respectively, an oxidizer supplying passage 17 is formed winding its way in the 1st end plat, and further a fuel supplying passage 16 is formed winding its way in the 2nd end plate.

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 having a power generation cell constituted by sandwiching a solid electrolyte layer between a fuel electrode layer and an oxidant electrode layer.

[0002]

2. Description of the Related Art Conventionally, as a fuel cell of this type, a power generation cell is composed of an anode, a solid electrolyte and a cathode, and separate plates are alternately stacked on the power generation cell. A solid oxide fuel cell in which the formed ribs distribute the fuel gas and the oxidizing gas individually to the anode and the cathode has been disclosed (JP-A-3-129675). In this fuel cell, the ribs are configured to flow the reactant gas radially from the center of the ribbed porous substrate toward the reactant gas outlet at the peripheral edge. Further, the reaction gas outlets are arranged so as to be evenly distributed around the periphery of the stack, which is a laminate of the separate plate and the power generation cell. Further, a fuel gas introduction pipe and an oxidizing gas introduction pipe are provided in the center of the stack so as to penetrate in the stacking direction, and the reaction gas is supplied to the separate plate from these introduction pipes. In the solid oxide fuel cell configured as described above, the reaction gas flows from the center of the stack toward the peripheral edge, so that a gas seal between the power generation cell and the separate plate is not required. Although the reaction gas discharged from the reaction gas discharge port burns around the fuel cell, the temperature distribution around the fuel cell is kept uniform because the distribution of the discharge port is uniform.

[0003]

However, in the conventional solid electrolyte fuel cell disclosed in Japanese Patent Application Laid-Open No. 3-129675, a preheater outside the fuel cell is introduced before the fuel gas is introduced into the fuel gas introduction pipe. Therefore, before the oxidizing gas is introduced into the oxidizing gas introducing pipe, it is necessary to preheat the fuel cell using a preheater outside the fuel cell, which increases the number of parts and increases the size of the apparatus. Further, in the conventional solid oxide fuel cell, the fuel gas introduction pipe and the oxidizing gas introduction pipe penetrate in the stacking direction at the center of the stack, which is a stack of the power generation cell and the separate plate. It is necessary to form two holes at substantially the center, and the surface area of the power generation cell contributing to power generation is reduced by the area of the two holes, resulting in a problem that power generation efficiency is reduced. Further, in the above-mentioned conventional solid oxide fuel cell, since the anode and the like and the porous substrate with ribs are in contact only with the ribs, the electron conductivity with the separate plate such as the anode is low, and the anode and the like contact the ribs. The reaction easily occurs only in the vicinity of the portion where the reaction occurs.
In other words, since the center of the groove between the ribs is not in contact with the anode or the like, before the electrons generated by the reaction reach the ribs, they disappear due to the electric resistance of the anode or the like,
There was also a problem that it was difficult to make the reaction take place over the entire power generation cell. Further, in the above-mentioned conventional solid oxide fuel cell, since the rib for guiding the reaction gas in a predetermined direction is formed on the ribbed porous substrate of the separate plate, the surface area of the power generation cell contributing to power generation is reduced. There is also a problem that the power generation efficiency is reduced due to the reduction by the contact area with the anode or the cathode. Furthermore, in the above-mentioned conventional solid oxide fuel cell, since a through hole for penetrating the fuel gas introduction pipe and the oxidant gas introduction pipe is formed in the center of the stack, the fuel gas introduction pipe and the oxidant gas introduction pipe are formed. There is a possibility that the fuel gas and the oxidizing gas leak from a gap between the fuel gas and the through-hole and mix and burn. Therefore, there is a problem that the power generation efficiency of the fuel cell is reduced. The method of filling the gap with ceramic cement is a solid oxide fuel cell (JP-A-6-19).
No. 6198), it was difficult to seal completely.

A first object of the present invention is to eliminate the need for a preheater for preheating fuel gas and oxidizing gas, thereby reducing the number of parts and achieving downsizing.
An object of the present invention is to provide a solid oxide fuel cell. A second object of the present invention is to allow all surfaces of a power generation cell that contributes to power generation to contribute to power generation, and to mix and burn fuel gas and oxidizing gas before supply to the power generation cell, that is, before power generation. It is therefore an object of the present invention to provide a solid oxide fuel cell which can prevent the occurrence of the above and improve the power generation efficiency. A third object of the present invention is to provide a solid oxide fuel cell that can reduce the time required for temperature rise at the time of startup and can prevent damage to a power generation cell by uniform temperature rise. A fourth object of the present invention is to control the flow of the fuel gas in the fuel electrode layer so that the number of collisions between the fuel gas and the fuel electrode layer can be increased. Heating the power generation cell evenly by flowing the layer almost uniformly
It is to provide a solid oxide fuel cell that can be cooled. A fifth object of the present invention is to join one or both of a fuel electrode current collector and an oxidizer electrode current collector to a separator made of stainless steel or the like, a first end plate and a second end plate, and Is welded to prevent oxidation of the joint portion, thereby obtaining a long-term electrical connection between the separator, the first end plate or the second end plate, and the anode current collector or the oxidizer electrode current collector. To provide a solid oxide fuel cell. A sixth object of the present invention is to provide a solid oxide fuel cell capable of reducing the number of parts and reducing the size by eliminating the need for a reformer for reforming fuel gas. It is in.

[0005]

According to the first aspect of the present invention,
As shown in FIG. 1, a power generation cell 11 including a solid electrolyte layer 11a formed of an oxide ion conductor and a fuel electrode layer 11b and an oxidant electrode layer 11c disposed on both surfaces of the solid electrolyte layer 11a is formed. (N + 1) (n is a positive integer) stacked solid oxide fuel cells 10,
Conduction between the fuel electrode layer 11b of the i-th (i = 1, 2,..., n) power generation cell 11 and the oxidant electrode layer 11c of the (i + 1) -th power generation cell 11 adjacent to the fuel electrode layer 11b. Each of the separators 12 formed of a conductive material in a plate shape has
A total of n fuel cells are interposed between the fuel electrode layer 11b of the i-th power generation cell 11 and the j-th (j = 1, 2,..., N) separator 12. Current collector 1
3, a porous oxidant electrode current collector 14 having conductivity is interposed between the oxidant electrode layer 11c of the (i + 1) -th power generation cell 11 and the j-th separator 12. The oxidant electrode current collector 1 is provided on the oxidant electrode layer 11c of the
4, a single first end plate 21 formed of a conductive material in a plate shape is laminated, and the (n + 1) -th power generation cell 11
A single second end plate 22 made of a conductive material is laminated on the fuel electrode layer 11b with the fuel electrode current collector 13 interposed therebetween, and the n separators 12
A fuel supply passage 16 that is introduced from the outer peripheral surface and flows to the approximate center while meandering, and is discharged from the approximate center of the separator 12 toward the anode current collector 13, and an oxidizing gas is introduced from the outer peripheral surface of the separator 12 to meander. Separator 12
An oxidizing agent supply passage 17 which flows through the inside and is discharged from a surface of the separator 12 facing the oxidizing electrode current collector 14,
The single first end plate 21 introduces the oxidizing gas from the outer peripheral surface of the first end plate 21 and flows in the first end plate 21 while meandering, and flows to the oxidizing electrode current collector 14 of the first end plate 21. A single second end plate 2 having an oxidant supply passage 27 for discharging from an opposing surface;
2 is characterized in that it has a fuel supply passage 26 for flowing the fuel gas to the approximate center while meandering from the outer peripheral surface of the second end plate 22 and discharging the fuel gas from the approximate center of the second end plate 22 toward the anode current collector 13. Is a solid oxide fuel cell.

In the solid oxide fuel cell according to the first aspect of the present invention, when the fuel gas is introduced into the fuel supply passages 16 and 26, the fuel gas meanders through the fuel supply passages 16 and 26 and the separator 12 and the second fuel gas. It faces substantially the center of the two end plates 22. Since the temperature of the fuel cell 10 during operation is high, the fuel gas flows through the fuel supply passages 16 and 26 while the separator 1
The heat is absorbed from the second and second end plates 22 and reaches a temperature optimum for the reaction in the fuel electrode layer 11b. The heated combustion gas is discharged from substantially the center of the separator 12 and the second end plate 22 toward the center of the anode current collector 13, passes through the inside of the anode current collector 13, and substantially passes through the anode layer 11 b. It is supplied to the center and further flows from the approximate center of the fuel electrode layer 11b toward the outer peripheral edge. On the other hand, when the oxidizing gas is introduced into the oxidizing agent supply passages 17 and 27, the oxidizing gas flows meandering in the oxidizing agent supply passages 17 and 27. Since the temperature of the fuel cell 10 during operation is high, the oxidant gas absorbs heat from the separator 12 and the first end plate 21 while passing through the oxidant supply passages 17 and 27,
The temperature reaches the optimum temperature for the reaction in the oxidant electrode layer 11c. The heated oxidant gas is supplied to the surface of the separator 12 facing the oxidant electrode current collector 14 and the oxidant electrode current collector 1 of the first end plate 21.
4 and is supplied to the oxidant electrode layer 11c through the inside of the oxidant electrode current collector 14, and further supplied to the oxidant electrode layer 11c.
It flows along the solid electrolyte layer 11a in c. The heated oxidant gas receives electrons from the oxidant electrode layer 11c and is quickly ionized into oxide ions, and the oxide ions diffuse and move in the solid electrolyte layer 11a, and move to the fuel electrode layer 1c.
1b. As a result, the oxide ions react with the heated fuel gas to quickly produce a reaction product and emit electrons to the fuel electrode layer 11b. Occurs and power is obtained.

The invention according to claim 2 is the invention according to claim 1, wherein each of the oxidant supply passages 17 formed in the n sheets of separators 12 has an oxidant supply passage, as shown in FIGS. A gas is introduced from the outer peripheral surface of the separator 12 and is meandered while being discharged almost uniformly in a shower form from the surface of the separator 12 facing the oxidant electrode current collector 14. The formed oxidant supply passage 27 introduces the oxidant gas from the outer peripheral surface of the first end plate 21 and meanders, while showering substantially uniformly from the surface of the first end plate 21 facing the oxidant electrode current collector 14. Characterized in that it is configured to discharge the ink. The invention according to claim 3 is the invention according to claim 2, wherein the oxidizing agent supply passage 17 formed in the n sheets of separators 12 has an outer peripheral surface of each of the separators 12, as shown in FIGS. Single oxidizer hole 1 opening in
7a and the first oxidant hole 17a.
A single second oxidizing agent hole 17b meandering inside 2 and a surface of separator 12 facing oxidizing electrode current collector 14 are formed at a predetermined interval and communicate with second oxidizing agent hole 17b. Oxidant supply passages 27 formed in a single first end plate 21 having a large number of third oxidant holes 17c.
A single first oxidizing agent hole 27a opening in the outer peripheral surface of the first oxidizing agent hole, a single second oxidizing agent hole 27b communicating with the first oxidizing agent hole 27a and meandering in the first end plate 21; The plate 21 has a large number of third oxidant holes 27c formed at a predetermined interval on the surface facing the oxidant electrode current collector 14 so as to communicate with the second oxidant holes 27b. I do. In the solid oxide fuel cell according to the second or third aspect, the oxidizing gas is discharged from the oxidizing agent supply passages 17 and 27 in a shower shape to the oxidizing electrode current collector 14 substantially uniformly. The oxidant gas can uniformly heat and cool the power generation cell 11. In addition, when the power generation cell 11 is heated and rises above a set temperature due to generation of Joule heat during power generation of the fuel cell 10, an oxidant gas having a temperature lower than the set temperature is discharged from the oxidant supply passages 17 and 27. By doing so, the power generation cell 11 can be cooled uniformly, so that damage due to local heating or cooling of the power generation cell 11 can be prevented.

The invention according to a fourth aspect is the invention according to the first aspect, and furthermore, as shown in FIG.
A single first oxidizing agent hole 57a opening on the outer peripheral surface of the second oxidizing agent hole 2, a single second oxidizing agent hole 57b communicating with the first oxidizing agent hole 57a and meandering in the separator 52 toward the center; The oxidant electrode current collector 14 communicates with the second oxidant hole 57b.
And a single third oxidant hole 57c facing substantially the center of the first end plate 61, and an oxidant supply passage 67 formed in the first end plate 61 is opened on the outer peripheral surface of the first end plate 61. An oxidant hole 67a;
A single second oxidizing agent hole 67b communicating with the first oxidizing agent hole 67a and meandering in the first end plate 61 and substantially toward the center; an oxidizing agent collector communicating with the second oxidizing agent hole 67b; Electric body 14
And a single third oxidizing agent hole 67c facing substantially the center of the hole. In the solid oxide fuel cell according to the fourth aspect, since the oxidant supply passages 57 and 67 have a relatively simple shape, the separator 52 and the first end plate 61 are provided.
Can reduce the number of manufacturing steps.

The invention according to claim 5 is the invention according to claims 1 to 4.
The fuel supply passages 16 and 26 and the oxidant supply passage 1 as shown in FIGS.
A plurality of insertion holes 12a are formed in each of the n separators 12, the single first end plate 21 and the single second end plate 22 so as not to communicate with any one of the insertion holes 7 and 27. The heater 23 or the heater 23 and the temperature sensor are respectively inserted into 12a. In the solid oxide fuel cell according to the fifth aspect, when the fuel cell 10 is started, the power is supplied to the heater 23 to generate the power generation cell 1.
Since the temperature of 1 can be raised quickly, the time required for raising the temperature can be shortened.
Further, since the temperature of the power generation cell 11 is uniformly increased and the temperature difference between the center and the outer peripheral edge of the power generation cell 11 is eliminated and the thermal expansion is performed uniformly, the damage of the power generation cell 11 can be prevented. Further, if the heater is controlled based on the detection output of the temperature sensor, the temperature of the separator and the like can be finely controlled.

The invention according to claim 6 is the invention according to claims 1 to 4
The invention according to any one of the above, further comprising a plurality of n separators, a single first end plate and a single second end plate, each of which is not connected to any of the fuel supply passage and the oxidant supply passage. Characterized in that a lightening hole is formed. In the solid oxide fuel cell according to the sixth aspect, the weight of the separator, the first end plate, and the second end plate can be reduced by forming the lightening holes, so that the weight of the fuel cell can be reduced. .

The invention according to claim 7 is the invention according to claims 1 to 6
As shown in FIGS. 1 and 4, the surfaces of the n separators 12 facing the anode current collector 13 and the anode current collection of the single second end plate 22 are further described. A plurality of slits 12b and 22b spirally extending from the center of each separator 12 and the second end plate 22 are formed on the surface facing the body 13, respectively. In the solid oxide fuel cell according to the seventh aspect, the separator 12 faces the anode current collector 13 and the second end plate 22 faces the anode current collector 13 in a spiral shape. Multiple slits 12
Since b and 22b are respectively formed, the fuel gas flows spirally along the slits 12b and 22b, and the reaction path of the fuel gas becomes longer. As a result, the fuel gas and the fuel electrode layer 1
The number of collisions with the fuel cell 1b increases, and the output of the fuel cell 10 can be improved.

The invention according to claim 8 is the invention according to claims 1 to 6
The invention according to any of the above, and as shown in FIG.
From the center of each of the separators 52 and the second end plate 62 to the surface of the n sheets of the separator 52 facing the anode current collector 13 and the surface of the single second end plate 62 facing the anode current collector 13. A plurality of radially extending slits 52b, 62b are formed. In the solid oxide fuel cell according to the eighth aspect, the surface of the separator 52 facing the anode current collector 13 and the anode current collector 1 of the second end plate 62.
A plurality of slits 52b, 62b radially on the surface facing
Respectively, so that the fuel gas flows through the slits 52b,
The fuel gas flows radially along 62b, and the reaction path of the fuel gas becomes relatively long. As a result, the number of collisions between the fuel gas and the fuel electrode layer 11b becomes relatively large, and the output of the fuel cell 50 can be improved.

The invention according to claim 9 is the invention according to claims 1 to 8
As shown in FIGS. 7 and 8, the opposing surfaces of the n separators 52 facing the oxidant electrode current collector 14 and the oxidant electrodes of the single first end plate 61 are further described. Current collector 14
A plurality of slits 52b and 61b are formed radially from the center of each separator 52 and the first end plate 61 on the surface facing the. In the solid oxide fuel cell according to the ninth aspect, the surface of the separator 52 facing the oxidant electrode current collector 14 and the surface of the first end plate 61 facing the oxidant electrode current collector 14 are radiated. Multiple slits 52
Since the b and 61b are respectively formed, the oxidizing gas flows radially along the slits 52b and 61b, and the reaction path of the oxidizing gas becomes relatively long. As a result, the number of collisions between the oxidant gas and the oxidant electrode layer 11c becomes relatively large, and the output of the fuel cell 50 can be improved.

The invention according to claim 10 is the invention according to any one of claims 1 to 9, wherein the anode current collector 13 is further plated with nickel, silver or copper as shown in FIG. Stainless steel, nickel-based alloy or chromium-based alloy, or stainless steel formed of nickel, silver or copper, and the oxidant electrode current collector 14 is plated with silver or platinum, nickel-based alloy or chromium-based alloy, or silver or The n number of separators 12, the first end plate 21 and the second end plate 22 are formed of stainless steel, a nickel-based alloy or a chromium-based alloy, respectively, and the anode current collector 13 is formed of platinum. 2
The oxidant electrode current collector 14 is joined to each of the end plates 22 and the separator 12 and the first end plate 21 respectively. In the solid oxide fuel cell according to claim 10, the separator 12 and the first end plate 21
Is exposed to oxidizing gas (high temperature oxidizing atmosphere) at high temperature,
A junction between the separator 12 and the oxidant electrode current collector 14,
Since the welded portions of the first end plate 21 and the oxidant electrode current collector 14 are welded, oxidation of these welded portions can be prevented. As a result, not only the electrical continuity of the separator 12 and the anode current collector 13 and the electrical continuity of the second end plate 22 and the anode current collector 13 but also the electrical connection of the separator 12 and the oxidant electrode current collector 14 are obtained. The electrical connection and the electrical connection between the first end plate 21 and the oxidant electrode current collector 14 can be maintained for a long period of time through the joint. Further, since the anode current collector 13 was previously joined to each of the separators 12 and the second end plate 22, and the oxidant electrode current collector 14 was joined to each of the separators 12 and the first end plate 21, respectively. The assembly work time can be shortened, and the assembly workability can be improved.

An eleventh aspect of the present invention is the invention according to any one of the first to tenth aspects, further comprising a surface of n separators, a surface of a single first end plate, and a single second end plate. Nickel plating, chromium plating or silver plating is applied to the surface of the plate. In the solid oxide fuel cell according to the eleventh aspect, electrical continuity between the separator, the first end plate, and the second end plate, and the fuel electrode current collector and the oxidant electrode current collector is further extended. Can hold.

A twelfth aspect of the present invention is the invention according to any one of the first to eleventh aspects, further characterized in that the fuel supply passage is filled with modified particles at a density at which fuel gas can flow. . In the solid oxide fuel cell according to the twelfth aspect, since the fuel gas is reformed by the reformed particles in the fuel supply passage, the reformer conventionally provided outside the fuel cell becomes unnecessary. . The modified particles are Ni, N
iO, Al ₂ O ₃ , SiO ₂ , MgO, CaO, Fe
₂ O ₃ , Fe ₃ O ₄ , V ₂ O ₃ , NiAl ₂ O ₄ , ZrO ₂ , S
iC, Cr ₂ O ₃ , ThO ₂ , Ce ₂ O ₃ , B ₂ O ₃ , Mn
It is preferably formed of an element or an oxide containing one or more selected from the group consisting of O ₂ , ZnO, Cu, BaO and TiO ₂ .

The invention according to claim 14 or 15 is shown in FIGS.
As shown in FIG. 3, the oxidizing agent supply passages 17 and 27 introduce the oxidizing gas from the outer peripheral surface and meander the oxidizing gas so that the oxidizing gas is discharged almost uniformly in a shower form from the surface facing the oxidizing electrode current collector 14. The configured separator or first end plate. The invention according to claim 16 or 17 is the invention according to claim 14 or 15, and furthermore, as shown in FIG. 1 to FIG. The first oxidizing agent holes 17a, 27a and the first oxidizing agent holes 17a, 27a
7a, a single second oxidant hole 17b meandering and meandering;
27b, and a plurality of third oxidant holes 17c, 27c formed at predetermined intervals on the surface facing the oxidant electrode current collector 14 and formed to communicate with the second oxidant holes 17b, 27b. It is a separator or a first end plate. Claim 14
In the separator or the first end plate described in any one of (1) to (17), the oxidizing gas is almost uniformly discharged from the oxidizing agent supply passages 17 and 27 in a shower shape toward the oxidizing electrode current collector 14. The power generation cell 11 can be uniformly heated and cooled by the oxidant gas. Also, when the power generation cell 11 is heated by the generation of Joule heat during the power generation of the fuel cell 10 and rises above the set temperature, the oxidant gas having a temperature slightly lower than the set temperature is supplied to the oxidant supply passages 17 and 27. Since the power generation cell 11 can be uniformly cooled by discharging the power generation cell, damage due to local heating or cooling of the power generation cell 11 can be prevented.

The invention according to claim 18 or 19 is shown in FIGS.
As shown in FIG. 3, the fuel supply passages 16 and 26 introduce the fuel gas from the outer peripheral surface and meander and discharge the fuel gas from the approximate center toward the anode current collector 13 while discharging the fuel gas from the center. It is a board. In the separator or the second end plate according to claim 18 or 19, the fuel supply passage 1 is provided.
Fuel gas introduced into the fuel supply passages 16 and 26
6 while being meandering, the separator 6 and the second end plate 22 are directed substantially to the center. Since the temperature of the fuel cell 10 during operation is high, the fuel gas absorbs heat from the separator 12 and the second end plate 22 while passing through the fuel supply passages 16 and 26, and is optimal for the reaction in the fuel electrode layer 11b. Reach temperature.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a first embodiment of the present invention will be described with reference to the drawings. As shown in FIGS. 1 to 4, the power generation cell 11 includes a disc-shaped solid electrolyte layer 11 a and disc-shaped fuel electrode layers 1 disposed on both surfaces of the solid electrolyte layer 11 a.
1b and an air electrode layer 11c (oxidizer electrode layer), and the solid oxide fuel cell 10
1) It is configured by stacking individual pieces. Here, n is a positive integer. Between the fuel electrode layer 11b of the i-th (i = 1, 2,..., n) power generation cell 11 and the air electrode layer 11c of the (i + 1) -th power generation cell 11 adjacent to the fuel electrode layer 11b, A total of n separators 12 each of which is formed of a conductive material and has a square plate shape with one side of the fuel electrode layer 11b and the air electrode layer 11c as one side are interposed. Further, between the fuel electrode layer 11b of the i-th power generation cell 11 and the j-th (j = 1, 2,..., N) separator 12, a fuel cell having the same outer diameter as the fuel electrode layer 11b and the air electrode layer 11c is provided. A (i + 1) -th power generation cell 11 is provided with a porous fuel electrode current collector 13 formed in a disc shape and having conductivity.
Is formed between the air electrode layer 11c and the j-th separator 12 in the form of a disk having the same outer diameter as the fuel electrode layer 11b and the air electrode layer 11c, and is a porous air electrode current collector having conductivity. A body 14 (oxidant electrode current collector) is interposed. Further, on the air electrode layer 11c of the first power generation cell 11, a single first end plate 21 formed in the same square shape as the separator 12 by a conductive material is stacked via the air electrode current collector 14. ,
In the fuel electrode layer 11b of the (n + 1) -th power generation cell 11,
A single second end plate 22 formed of the same square shape as the separator 12 by a conductive material via the anode current collector 13
Are laminated. The solid electrolyte layer, fuel electrode layer, air electrode layer, fuel electrode current collector and air electrode current collector are not disc-shaped,
It may be formed in a polygonal plate shape such as a square plate shape, a hexagonal plate shape, and an octagonal plate shape. In addition, the separator, the first end plate and the second
The end plate may be formed not in a square plate shape but in a disc shape, or a polygonal plate shape such as a rectangular plate shape, a hexagonal plate shape, and an octagonal plate shape.

The solid electrolyte layer 11a is formed of an oxide ion conductor. Specifically, the general formula (1): Ln1
An oxide ion conductor represented by A Ga B1 B2 B3 O. However, in the above general formula (1), Ln1
Is one or more elements selected from the group consisting of La, Ce, Pr, Nd and Sm, and is 43.6 to 51.
A is one or more elements selected from the group consisting of Sr, Ca and Ba, and 5.4 to 1
1.1% by weight, and Ga is 20.0 to 23.9% by weight.
B1 is one or more elements selected from the group consisting of Mg, Al and In, and B2 is Co, F
e, one or more elements selected from the group consisting of Ni and Cu, and B3 is Al, Mg, Co, Ni, F
e, one or two or more elements selected from the group consisting of Cu, Zn, Mn and Zr, and when B1 and B3 or B2 and B3 are not the same element, B1 is 1.21
１1.76% by weight, B2 0.84０．８1.26% by weight, B3 0.23〜3.08% by weight,
When B1 and B3 or B2 and B3 are the same element, the total of the content of B1 and the content of B3 is 1.41 to
2.70% by weight, and the total of the B2 content and the B3 content is 1.07 to 2.10% by weight.

The solid electrolyte layer 11a is represented by the following general formula (2):
_{Ln1 1-x A x Ga 1} -yzw B1 y B2 z B3 w O in _3-d may be formed of an oxide ion conductor represented. However, in the general formula (2), Ln1 is La, Ce,
One or two selected from the group consisting of Pr, Nd and Sm
A is one or more elements selected from the group consisting of Sr, Ca, and Ba;
1 is one or more elements selected from the group consisting of Mg, Al and In, and B2 is one or more elements selected from the group consisting of Co, Fe, Ni and Cu Where B3 is Al, Mg, Co, Ni, Fe, C
one or more elements selected from the group consisting of u, Zn, Mn and Zr, wherein x is 0.05 to 0.3, y
Is 0.025 to 0.29, z is 0.01 to 0.15, w
Is 0.01-0.15, and y + z + w is 0.035-0.
3 and d are 0.04 to 0.3. By forming the solid electrolyte layer 11a with the oxide ion conductor as described above, the power generation operation can be performed at a relatively low temperature of 650 ± 50 ° C. without lowering the power generation efficiency of the fuel cell 10. Become.

The fuel electrode layer 11b is made of a metal such as Ni, a cermet such as Ni-YSZ, or Ni and a general formula (3): Ce _1-m D _m O.
It is formed porous by a mixture with the compound represented by ₂ . However, in the above general formula (3), D is Sm, G
one or more elements selected from the group consisting of d, Y, and Ca; m is the atomic ratio of the D element;
To 0.4, preferably 0.1 to 0.3.

The air electrode layer 11c has a general formula (4): Ln2
It is formed on the porous of an oxide ion conductor represented by _{1-x Ln3 x E 1-} y Co y O 3 + d. However, in the above general formula (4), Ln2 is one or both elements of La and Sm, and Ln3 is Ba, Ca or Sr
E is Fe or C
u is one or both elements. X is Ln
It is an atomic ratio of 3 and is set in a range of more than 0.5 and less than 1.0. y is the atomic ratio of the Co element, and exceeds 0 to 1.
0 or less, preferably 0.5 or more and 1.0 or less. d is set in a range from -0.5 to 0.5.

An example of a method for manufacturing the power generation cell 11 will now be described.
Shown in First, as raw material powder, La _TwoO_Three, SrCO_Three,
Ga_TwoO_ThreeLa, MgO and CoO powders_0.8Sr_0.2G
a_0.8Mg_0.15Co_0.05O_2.8Weigh and mix so that
And then calcined at 1100 ° C to produce a calcined body
You. Next, after the calcined body is crushed,
Slurry by adding and mixing
The slurry is greened by the doctor blade method.
Make a sheet. Next, put this green sheet in the air
After drying sufficiently and cutting out to predetermined dimensions, 1450 ° C
To obtain the solid electrolyte layer 11a. this
On one surface of the solid electrolyte layer 11a, Ni and (Ce_0.8S
m_0.2) O_TwoNiO powder so that the volume ratio becomes 6: 4.
And (Ce_0.8Sm_0.2) O_TwoAfter mixing with the powder, this
By baking the mixed powder at 1100 ° C., the fuel electrode layer 1
1b is formed. Further, the other of the solid electrolyte layer 11a
(Sm_0.5Sr_0.5) CoO_ThreeBake at 1000 ° C
This forms the air electrode layer 11c. Like this
Thus, the power generation cell 11 is manufactured.

The separator 12 is preferably made of stainless steel, a nickel-based alloy or a chromium-based alloy. For example, SUS316, Inconel 600, Hastelloy X (trade name of Haynes Stellite), Haines Alloy 214, and the like can be given. Further, a fuel supply passage 16, an air supply passage 17 (oxidant supply passage), and a plurality of insertion holes 12a are formed in the separator 12 (FIGS. 1 to 3). In this embodiment, the horizontal plane including the fuel supply passage 16 is configured to be located a predetermined distance above the horizontal plane including the air supply passage 17. Fuel supply passage 16
Is a single first fuel hole 16a opened at the center of the first side 12d of the separator 12 and substantially toward the center of the separator 12, and communicates with the first fuel hole 16a so as to meander through the inside of the separator 12. Single second fuel hole 1 facing
6b and the anode current collector 1 communicating with the second fuel hole 16b.
3 and a single third fuel hole 16c facing substantially the center (FIG. 2). The air supply passage 17 has a single first air hole 17a opened at the center of the third side 12f of the separator 12 and substantially toward the center of the separator 12, and communicates with the first air hole 17a to meander inside the separator 12. A single second air hole 17b facing the first side 12d, and a large number formed at a predetermined interval on the surface of the separator 12 facing the air electrode current collector 14 so as to communicate with the second air hole 17b. And a third air hole 17c.

The second fuel hole 16b is provided in the first
A plurality of fuel straight holes 16d parallel to the side 12d;
A plurality of fuel grooves 16e formed on the second side 12e and the fourth side 12g of the separator 12 so as to alternately communicate the ends of the adjacent fuel straight holes 16d among the fuel straight holes 16d. The fuel grooves 16e are formed by silver brazing a pair of side plates 12c, 12c (formed of the same material as the separator 12) to the second side 16e and the fourth side 16g of the separator 12.
It is sealed by joining by laser welding or the like, and becomes a plurality of fuel communication holes 16f (FIG. 2). Second air hole 1
7b is a plurality of straight holes 17d for air parallel to the third side 12f of the separator 12, and straight holes 17d adjacent to each other among the straight holes 17d for air.
d of the separator 12 so that the ends of the
It comprises a plurality of air grooves 17e formed on the side 12e and the fourth side 12g. These air grooves 17e are sealed by the pair of side plates 12c, 12c, and a plurality of air communication holes 17f. (FIG. 3).

A fuel supply pipe 18 is connected to a base end of the first fuel hole 16a, and an air supply pipe 19 is connected to a base end of the first air hole 17a (FIGS. 2 and 3). The plurality of insertion holes 12a do not communicate with either the fuel supply passage 16 or the air supply passage 17, and the plurality of fuel straight holes 1a.
6d and the first side 12d of the separator 12 and the third side 12d so as to be located between the plurality of straight holes 17d for air.
These insertion holes 1 are formed in parallel with the sides 12f, respectively.
The heaters 23 are respectively inserted into the 2a. On the surface of the separator 12 facing the anode current collector 13, three slits 12b are respectively formed in a spiral shape from substantially the center of the separator 12 (FIG. 4), and the depth of these slits 12b is the same over the entire length. It is formed so that The number of the slits is not limited to three, but may be two or four or more. Further, the depth of the slit may be formed so as to gradually increase or decrease as the distance from the center of the separator increases.

Returning to FIG. 1, the anode current collector 13 is made of stainless steel, a nickel-based alloy or a chromium-based alloy, or is made of nickel, silver or copper, and is made of stainless steel, a nickel-based alloy or a chromium-based alloy. When formed by nickel plating, it is preferable to apply nickel plating, silver plating or copper plating. The air electrode current collector 14 is formed of stainless steel, silver or platinum, and is preferably made of stainless steel, a nickel-based alloy, or a chromium-based alloy. When hydrocarbons are used as fuel gas,
The anode current collector is formed of nickel-plated stainless steel, a nickel-based alloy or a chromium-based alloy, or nickel.When hydrogen is used as a fuel gas, the anode current collector is plated with silver or copper. Formed of stainless steel, nickel-based alloy or chromium-based alloy, or silver or copper. An example of a method for manufacturing the anode current collector 13 will be described below. First, after kneading the atomized powder such as stainless steel and HPMC (water-soluble resin binder),
Distilled water and additives (n-hexane (organic solvent), DBS
(Surfactant), glycerin (plasticizer) and the like are added and kneaded to prepare a mixed slurry. Next, after forming a compact from the mixed slurry by a doctor blade method, foaming, degreasing and sintering are performed under predetermined conditions to obtain a porous plate. Further, the porous plate is cut into a predetermined size, and the anode current collector 1 is cut out.
3 is manufactured. When stainless steel atomized powder is used, the surface is plated with nickel, chrome, or silver. The air electrode current collector 14 is also manufactured in substantially the same manner as the fuel electrode current collector 13.

The first end plate 21 and the second end plate 22 are formed of the same material as the separator 12 in the same square plate shape as the separator 12 and thinner than the separator 12. First
An air supply passage 27 and a plurality of insertion holes (not shown) are formed in the end plate 21, and a fuel supply passage 26 is formed in the second end plate 22.
And a plurality of insertion holes (not shown) are formed (FIG. 1).
The air supply passage 27 is formed in the same shape as the air supply passage 17 and opens at the center of the third side of the first end plate 21 to open the first end plate 21.
And a single first air hole (not shown) facing the approximate center of the first end plate 21 communicating with the first air hole and meandering in the first end plate 21.
A single second air hole 27b directed to the side, and a plurality of air holes formed at predetermined intervals on the surface of the first end plate 21 facing the air electrode current collector 14 so as to communicate with the second air hole 27b. The third
And an air hole 27c. The fuel supply passage 26 is formed in the same shape as the fuel supply passage 16, and is opened at the center of the first side of the second end plate 22, and has a single first fuel hole (shown in FIG. ) And the second fuel hole
A single second fuel hole 26b that is meandering in the end plate 22 and substantially toward the center of the second end plate 22, and a single second fuel hole 26b that communicates with the second fuel hole 26b and faces substantially the center of the anode current collector 13; And a third fuel hole 26c.

The second air hole 27b is formed similarly to the second air hole 17b, and the second fuel hole 26b is formed similarly to the second fuel hole 16b. Reference numeral 21c in FIG. 1 denotes a pair of side plates (formed of the same material as the first end plate) joined to the second side 21e and the fourth side 21g of the first end plate 21 by silver brazing, laser welding, or the like. ), The second air holes 27b meander by joining these side plates. Further, reference numeral 22c in FIG. 1 denotes the second side 22e of the second end plate 22 and the fourth side 22e.
A pair of side plates (formed of the same material as the second end plate) joined to the side 22g by silver brazing, laser welding, or the like, and the second fuel holes 26b meander by joining these side plates. It is composed of An air supply pipe (not shown) is connected to a base end of the air supply passage 27 of the first end plate 21, and a fuel supply pipe (not shown) is connected to a base end of the fuel supply passage 26 of the second end plate 22. Is connected. Also, the first end plate 21
Are formed in parallel with the first side of the first end plate 21 so as not to communicate with the air supply passage 27, and heaters are inserted into these insertion holes, respectively. Also, the second end plate 22
Are formed parallel to the third side of the second end plate 22 so as not to communicate with the fuel supply passage 26, and heaters are inserted into these insertion holes, respectively. A plurality of slits 22b are formed in a spiral shape from substantially the center of the second end plate 22 on the upper surface of the second end plate 22, that is, on the surface of the second end plate 22 facing the anode current collector 13 (FIG. 1). ). These slits 22b
Are formed so as to have the same width and depth over the entire length of the slit 22b. The width of the slit may be formed so as to gradually increase as the distance from the center of the second end plate increases, or the depth of the slit may be formed so as to gradually increase or decrease as the distance from the center of the second end plate increases. Good.

At four corners of the separator 12, the first end plate 21 and the second end plate 22, through holes 12c through which bolts (not shown) can be inserted are formed (FIGS. 2 and 3). (N + 1)
Power generation cells 11, n separators 12, (n +
1) anode current collectors 13, (n + 1) cathode current collectors 14, a single first end plate 21, and a single second end plate 2
2 are stacked, bolts are respectively inserted into through holes 12c formed at the four corners of the separator 12, the first end plate 21 and the second end plate 22, and then nuts are screwed into the tips of these bolts. By combining, the fuel cell 10
Are fixed in the state of being stacked. Further, the fuel supply passage 1 of the separator 12 and the second end plate 22
Modified particles (not shown) are filled in the fuel cells 6 and 26 at a density at which the fuel gas can flow. The modified particles are Ni, NiO,
Al ₂ O ₃ , SiO ₂ , MgO, CaO, Fe ₂ O ₃ , Fe ₃
O ₄ , V ₂ O ₃ , NiAl ₂ O ₄ , ZrO ₂ , SiC, Cr ₂
O ₃ , ThO ₂ , Ce ₂ O ₃ , B ₂ O ₃ , MnO ₂ , ZnO,
It is preferably formed of an element or oxide containing one or more selected from the group consisting of Cu, BaO and TiO ₂ .

The operation of the solid oxide fuel cell 10 thus configured will be described. When the fuel gas (for example, methane gas (CH ₄ )) is introduced into the fuel supply pipe 18 together with the steam (H ₂ O), the fuel gas and the steam meander in the fuel supply passages 16 and 26 and the separator 12 and the second
It faces substantially the center of the end plate 22. Since the temperature of the fuel cell 10 during operation is high, the fuel gas absorbs heat from the separator 12 and the second end plate 22 while passing through the fuel supply passages 16 and 26, and is optimal for the reaction in the fuel electrode layer 11b. Upon reaching the temperature, the fuel is reformed by the reformed particles filled in the fuel supply passages 16 and 26 (for example, reformed into hydrogen gas (H ₂ )). The heated and reformed fuel gas flows from substantially the center of the separator 12 and the second end plate 22 to the anode current collector 1.
3 and is quickly supplied to the approximate center of the fuel electrode layer 11b through pores in the fuel electrode current collector 13,
Further, the fuel is guided by the slits 12b and 22b and spirally flows from the approximate center of the fuel electrode layer 11b toward the outer peripheral edge.

On the other hand, when air (oxidizing gas) is introduced into the air supply pipe 19, the air meanders in the air supply passages 17, 27 and the first side 12d of the separator 12 and the first side.
It faces the first side of the end plate 21. Since the temperature of the fuel cell 10 during operation is high, the air absorbs heat from the separator 12 and the first end plate 21 while passing through the air supply passages 17 and 27,
The temperature reaches the optimum temperature for the reaction in the air electrode layer 11c. The heated air is discharged from the separator 12 and the third air holes 17 c and 27 c of the first end plate 21 toward the air electrode current collector 14 in a shower shape. As a result, the air passes through the pores in the cathode current collector 14 and is supplied to the cathode layer 11c substantially uniformly.

The air supplied to the air electrode layer 11c passes through pores in the air electrode layer 11c and reaches the vicinity of the interface with the solid electrolyte layer 11a. At this portion, oxygen in the air releases electrons from the air electrode layer 11c. And is quickly ionized into oxide ions (O ²⁻ ). The oxide ions diffuse and move in the solid electrolyte layer 11a in the direction of the fuel electrode layer 11b, and when they reach the vicinity of the interface with the fuel electrode layer 11b, they react with the heated fuel gas at this portion and quickly react. A reaction product (for example, H ₂ O) is generated, and electrons are emitted to the fuel electrode layer 11b. By extracting these electrons from the anode current collector 13, a current is generated and electric power is obtained. As described above, the fuel gas flows substantially in the center of the separator 12 and the second end plate 22.
Of the fuel gas and guided by the slits 12b and 22b, the reaction path of the fuel gas becomes longer.
As a result, the fuel gas passes through the separator 12 and the second end plate 22.
Since the fuel gas collides with the fuel electrode layer 13 very much before reaching the outer peripheral edge of the fuel cell 10, the number of times of the reaction increases, and the performance of the fuel cell 10 can be improved. Therefore, as the outer diameters of the separator 12 and the second end plate 22 become larger, the reaction path of the fuel gas becomes longer, and accordingly, the number of reactions increases, which leads to an improvement in the output of the fuel cell 10.

On the other hand, since a large number of third air holes 17c are formed at predetermined intervals on the lower surface of the separator 12 and the lower surface of the first end plate 21, air flows through the separator 1.
2 and the lower surface of the first end plate 21. As a result, the power generation cell 11 is uniformly heated by air.
Can be cooled. In particular, when the power generation cell 11 is heated by the generation of Joule heat during power generation of the fuel cell 10 and rises above a set temperature (for example, 650 ° C.), a temperature (for example, 630) slightly lower than this set temperature is set. By discharging air from the air supply passages 17 and 27,
Since the power generation cell 11 can be cooled uniformly, damage due to local heating or cooling of the power generation cell 11 can be prevented.

A conventional fuel cell, that is, a fuel gas introduction pipe and an oxidizing gas introduction pipe for inserting a fuel gas introduction pipe and a oxidizing gas introduction pipe approximately at the center of the power generation cell.
Since the pores are formed, the reaction area is small, and the fuel gas is mixed with the air before the reaction, so that the fuel cell 10 of the present invention has the surface of the power generation cell 11 as compared with the fuel cell in which the power generation efficiency is reduced. All contribute to power generation, and the fuel gas does not mix with air before the reaction, thereby improving power generation efficiency. The (n + 1) power generation cells 11 are connected in series via a separator 12, a fuel electrode current collector 13, and an air electrode current collector 14 formed of a conductive material, and formed at both ends by a conductive material. Since the provided first end plate 21 and second end plate 22 are provided, large electric power can be taken out from the first end plate 21 and the second end plate 22.

When the fuel cell 10 is started, the heater 2
3, the temperature of the power generation cell 11 can be quickly raised by energizing the power generation cell 3.
1 is uniformly heated, and the temperature difference between the center and the outer peripheral edge of the power generation cell 11 is eliminated and the thermal expansion is performed uniformly.
Damage can be prevented. When the heater is not inserted into the insertion hole, that is, when the insertion hole is a lightening hole, the weight of the separator, the first end plate, and the second end plate can be reduced. Can be.

Further, on the upper surfaces of the separator 12 and the second end plate 22 made of stainless steel, nickel-based alloy or chromium-based alloy, nickel-plated, silver-plated or copper-plated stainless steel, nickel-based alloy or chromium-based alloy, or The nickel, silver or copper anode current collector 13 is joined to each other, and the stainless steel, the nickel-based alloy or the chromium-based alloy separator 12 and the lower surface of the second end plate 22 are silver-plated or platinum-coated stainless steel. If the air electrode current collector 14 made of nickel-based alloy or chromium-based alloy, or silver or platinum is joined, respectively, even if the separator 12 and the first end plate 21 are exposed to air at a high temperature, Even if the first end plate 21 is exposed to a high-temperature oxidizing atmosphere, the first end plate 22 and the joining portion of the separator 12 and the cathode collector 14 are connected to each other. Since welded joint portion Kikyoku collector 14 is welded, it can prevent oxidation of these joint parts. As a result, not only the electrical continuity between the separator 12 and the anode current collector 13 and the electrical continuity between the second end plate 22 and the anode current collector 13 but also the electrical connection between the separator 12 and the cathode current collector 14 are obtained. The continuity and the electrical continuity between the first end plate 21 and the air electrode current collector 14 can be maintained for a long period of time through the joining portion, and the joining can shorten the assembling work time of the fuel cell 10 and improve the assembling workability. . In addition, as said joining method, silver brazing, spot welding, laser welding, etc. are mentioned. In addition, stainless steel, nickel-based alloy or chromium-based alloy separator 12,
If nickel plating, chromium plating or silver plating is applied to the first end plate 21 and the second end plate 22, the separator 12, the first
Electrical continuity between the end plate 21 and the second end plate 22 and the fuel electrode current collector 13 and the air electrode current collector 14 can be maintained for a longer period.

FIGS. 5 to 9 show a second embodiment of the present invention. 5 to 9, the same reference numerals as those in FIGS. 1 to 4 indicate the same parts. In this embodiment, the air supply passage 57 formed in the separator 52 has a single first air hole 57a opened on the outer peripheral surface of each separator 52, and the air supply passage 57 communicates with the first air hole 57a to meander inside the separator 52. And a single second air hole 57b facing substantially the center.
b and a single third air hole 57c facing substantially the center of the air electrode current collector 14. The air supply passage 67 formed in the first end plate 61 has a single first air hole 67a opened on the outer peripheral surface of the first end plate 61, and the first air hole 67a.
A single second air hole 67b communicating with the first end plate 61 and meandering substantially toward the center, and a single second air hole 67b communicating with the second air hole 67b and substantially facing the center of the air electrode current collector 14. And a third oxidizing agent hole 67c. In this embodiment, the horizontal plane including the fuel supply passage 16 is configured to be located on the same plane as the horizontal plane including the air supply passage 17.

The second fuel hole 56b is provided on the first
A plurality of fuel straight holes 56d parallel to the side 52d;
A plurality of fuel grooves 56e formed on the second side 52e and the fourth side 52g of the separator 52 so as to alternately communicate the ends of the adjacent fuel straight holes 56d among the fuel straight holes 56d. These fuel grooves 56e are formed by joining a pair of side plates 52c, 52c (formed of the same material as the separator) to the second side 56e and the fourth side 56g of the separator 52 by silver brazing, laser welding, or the like. To form a plurality of fuel communication holes 56f (FIGS. 6 and 9). The second air holes 57b alternately communicate the plurality of straight air holes 57d parallel to the third side 52f of the separator 52 and the ends of the straight air holes 57d adjacent to each other among the straight air holes 57d. And a plurality of air grooves 57e formed on the second side 52e and the fourth side 52g of the separator 52, and these air grooves 57e are sealed by the pair of side plates 52c, 52c. And a plurality of communication holes 57f for air.

The fuel supply pipe 18 is connected to the base end of the first fuel hole 56a, and the air supply pipe 19 is connected to the base end of the first air hole 57a (FIGS. 6 to 9). The plurality of insertion holes 52a do not communicate with any of the fuel supply passage 56 and the air supply passage 57, and the plurality of fuel straight holes 56a.
d and between the plurality of straight holes 57d for air are formed in parallel with the first side 52d and the third side 52f of the separator 52, respectively.
The heaters 63 are inserted into a (FIGS. 6, 8 and 9). A plurality of slits 52b are formed on both surfaces of the separator 52 radially from substantially the center of the separator 52 (FIGS. 7 to 9). These slits 52b
Are formed so as to have the same width and depth over the entire length of the slit 52b. The width of the slit may be gradually increased as the distance from the center of the separator increases, or the depth of the slit may be gradually increased or decreased as the distance from the center of the separator increases.

The first end plate 61 and the second end plate 62 are formed of the same material and the same size as the separator 52. An air supply passage 67 and a plurality of insertion holes 61a are formed in the first end plate 61, and a fuel supply passage 66 and a plurality of insertion holes 62a are formed in the second end plate 62 (FIGS. 5 and 8). The air supply passage 67 is formed in the same shape as the air supply passage 57,
The first end plate 61 is opened at the center of the third side 61 f of the first end plate 61.
And a single first air hole 67a facing substantially the center of the first end plate 61 while communicating with the first air hole 67a.
A single second air hole 67b facing the side 61d;
A plurality of third air holes 67c formed at a predetermined interval on the surface facing the one air electrode current collector 14 so as to communicate with the second air holes 67b. Also, the fuel supply passage 66
Are formed in the same shape as the fuel supply passage 56, and the second end plate 6
A first fuel hole 66a opening at the center of the first side 62d of the second end plate 62 and substantially toward the center of the second end plate 62;
A single second fuel hole 66b communicating with the second end plate 62 and substantially to the center of the second end plate 62 while meandering in the second end plate 62, and a substantial portion of the air electrode current collector 14 communicating with the second fuel hole 66b. And a single third fuel hole 66c facing the center.

The second air holes 67b are a plurality of straight air holes 67d parallel to the third side 61f of the first end plate 61, and the ends of the straight air holes 67d adjacent to each other among the straight air holes 67d. And a plurality of air grooves (not shown) formed on the second side 61e and the fourth side 61g of the first end plate 61 so as to communicate the parts alternately. The second side 61e of the one end plate 61 and the fourth side
A pair of side plates 61c, 61c (first
The end plate 61 is formed of the same material. ) Is joined by silver brazing, laser welding or the like to form a plurality of air communication holes (not shown) (FIGS. 5 and 8). The second fuel hole 66b is formed on the first side 6 of the second end plate 62.
A second side 62e of the second end plate 62 is formed so as to alternately communicate the plurality of fuel straight holes 66d parallel to 2d and the ends of the fuel straight holes 66d adjacent to each other among the fuel straight holes 66d. And a plurality of fuel grooves (not shown) formed on the fourth side 62g. These fuel grooves 66e are formed on the second side 66e and the fourth side 66g of the second end plate 62. Side plates 62c, 62c (second end plate 6)
2 and the same material. ) Are joined by brazing, laser welding or the like to form a plurality of fuel communication holes (not shown).

The air supply pipe 19 is connected to the base end of the first air hole 67a, and the fuel supply pipe 18 is connected to the base end of the first fuel hole 66a (FIG. 8). The plurality of insertion holes 61a of the first end plate 61 are formed in parallel with the first side 61d of the first end plate 61 so as not to communicate with the air supply passage 67 and to be located between the straight holes 67d for air. The heaters 63 are inserted into these insertion holes 61a, respectively. The plurality of insertion holes 62a of the second end plate 62 are formed in parallel with the third side 62f of the second end plate 62 so as not to communicate with the fuel supply passage 66 and to be located between the fuel straight holes 66d. The heater 63 is inserted into each of the insertion holes 62a. A plurality of slits 61b are formed radially from substantially the center of the first end plate 61 on the lower surface of the first end plate 61, that is, on the surface of the first end plate 61 facing the air electrode current collector 14. A plurality of slits 62b are formed radially from substantially the center of the second end plate 62 on the upper surface of the second end plate 62, that is, on the surface of the second end plate 62 facing the anode current collector 13 (FIG. 8). The width and depth of these slits 61b, 62b are
Are formed so as to be the same over the entire length. In addition, the width of the slit is formed so as to gradually increase as the distance from the center of the first end plate and the second end plate,
Alternatively, the slit may be formed so that the depth of the slit gradually increases or decreases as the distance from the center of the first end plate and the center of the second end plate increases. Except for the above, the configuration is the same as that of the first embodiment.

In the solid oxide fuel cell 50 configured as described above, the fuel gas (for example, methane gas (C
H ₄ )) together with steam (H ₂ O)
When the fuel gas and steam are introduced into the fuel supply passage 5,
6 and 66, it heads to the center of the separator 52 and the second end plate 62 while meandering. Since the temperature of the fuel cell 50 during operation is high, the fuel gas absorbs heat from the separator 52 and the second end plate 62 while passing through the fuel supply passages 56 and 66,
The temperature reaches an optimum temperature for the reaction in the fuel electrode layer 11b, and is reformed by the reformed particles filled in the fuel supply passages 56 and 66 (for example, reformed to hydrogen gas (H ₂ )). The heated and reformed fuel gas is supplied from substantially the center of the separator 52 and the second end plate 62 to the anode current collector 1.
3 and is quickly supplied to the approximate center of the fuel electrode layer 11b through pores in the fuel electrode current collector 13,
Further, the fuel flows are guided by the slits 52b and 62b and radially flow from the approximate center of the fuel electrode layer 11b toward the outer peripheral edge.

On the other hand, when the air (oxidizing gas) is introduced into the air supply pipe 19, the air is meandering in the air supply passages 57 and 67, and is directed substantially to the center of the separator 52 and the first end plate 61. Since the temperature of the fuel cell 50 during operation is high, the air absorbs heat from the separator 52 and the first end plate 61 while passing through the air supply passages 57 and 67, and the air electrode layer 11c
To the optimal temperature for the reaction at The heated air is discharged from substantially the center of the separator 52 and the first end plate 61 toward the center of the cathode current collector 14, passes through the pores in the cathode current collector 14, and forms the air electrode layer 11 c. It is quickly supplied to the approximate center, and further guided by the slit, and flows radially from the approximate center of the air electrode layer 11c to the outer peripheral edge. As a result,
As in the first embodiment, the power generation efficiency of the fuel cell is improved. Further, since the separator 52 can be formed thinner than the separator of the first embodiment, the fuel cell 50 can be smaller than the fuel cell of the first embodiment. Operations other than those described above are substantially the same as the operations of the first embodiment, and thus the repeated description will be omitted.

In the first and second embodiments,
Although air is used as the oxidizing gas, oxygen or another oxidizing gas may be used. In the first and second embodiments, the separator is formed of stainless steel, a nickel-based alloy or a chromium-based alloy, but is formed of a conductive ceramic such as lanthanum chromite (La _0.9 Sr _0.1 CoO ₃ ). May be. Furthermore, in the first and second embodiments, the separator, the first end plate, and the second
Although the heaters are inserted into the insertion holes of the end plates, heaters and temperature sensors (thermocouples for temperature measurement) may be inserted alternately. In this case, the temperature of the separator and the like can be finely controlled by controlling the heater based on the detection output of the temperature sensor.

[0048]

As described above, according to the present invention,
A total of n separators are interposed between the fuel electrode layer of the i-th power generation cell and the oxidant electrode layer of the (i + 1) -th power generation cell out of the (n + 1) power generation cells. A porous anode current collector is interposed between the layer and the separator,
A porous oxidant electrode current collector is interposed between the oxidant electrode layer and the separator, and a meandering fuel supply passage and an oxidant supply passage are formed in each separator, and the oxidant electrode layer of the first power generation cell is formed. A meandering oxidant supply passage was formed in the stacked first end plate, and a meandering fuel supply passage was formed in the second end plate stacked on the fuel electrode layer of the (n + 1) th power generation cell.
After the fuel gas is heated while passing through the meandering fuel supply passage, flows from the substantially center of the fuel electrode layer toward the outer peripheral edge,
After the oxidant gas is heated while passing through the meandering oxidant supply passage, it flows in the oxidant electrode layer along the solid electrolyte layer. At this time, the heated oxidant gas receives electrons from the oxidant electrode layer and is quickly ionized into oxide ions, and the oxide ions diffuse and move in the solid electrolyte layer and near the interface with the fuel electrode layer. It reacts with the heated fuel gas to quickly produce a reaction product and emits electrons to the fuel electrode layer. As a result, a preheater provided outside the fuel cell for preheating the fuel gas and the oxidizing gas in the related art becomes unnecessary, so that the number of parts can be reduced and the fuel cell can be downsized. In addition, since the entire surface of the power generation cell contributes to power generation, the number of collisions between the fuel gas and the fuel electrode layer and the number of collisions with the oxidant gas and the oxidant electrode layer increase, thereby improving power generation efficiency.

Each of the oxidizing agent supply passages formed in the separator or the first end plate introduces an oxidizing gas from the outer peripheral surface of the separator or the first end plate while meandering. If it is configured so as to be discharged almost uniformly in a shower shape from the surface facing the current collector, the oxidant gas is discharged almost uniformly from the oxidant supply passage toward the oxidant electrode current collector in a shower shape. The oxidant gas can uniformly heat and cool the power generation cell. Further, by generating Joule heat during power generation of the fuel cell, when the power generation cell is heated and rises above a set temperature, an oxidant gas having a temperature slightly lower than the set temperature is discharged from the oxidant supply passage. Since the power generation cell can be uniformly cooled, damage due to local heating or cooling of the power generation cell can be prevented. The oxidant supply passage formed in the separator and the first end plate has a single first oxidant hole, a meandering and single central oxidant hole facing the center, and an oxidant electrode current collector. If each of them has a single third oxidizing hole facing the center, the oxidizing agent supply passage is relatively short, so that the number of manufacturing steps for the separator and the first end plate can be reduced, and the Since the agent supply passage can be formed on substantially the same plane as the fuel supply passage, the thickness of the separator can be reduced.

A plurality of insertion holes are formed in each of the n separators, the single first end plate and the single second end plate so as not to communicate with either the fuel supply passage or the oxidant supply passage. If the heaters are inserted into these insertion holes, the temperature of the power generation cells can be quickly raised by supplying power to the heaters when the fuel cell is started, so that the time required for the temperature increase can be shortened. In addition, the temperature of the power generation cell is uniformly increased, and the temperature difference between the center and the outer peripheral edge of the power generation cell is eliminated so that the power generation cell is uniformly thermally expanded. If a heater and a temperature sensor are inserted into the plurality of insertion holes, the temperature of the separator and the like can be finely controlled by controlling the heater based on the detection output of the temperature sensor. Further, if a plurality of lightening holes are formed in each of the n separators, the single first end plate and the single second end plate so as not to communicate with any of the fuel supply passage and the oxidant supply passage, Since the weight of the separator, the first end plate, and the second end plate can be reduced, the weight of the fuel cell can be reduced.

The surfaces of the n separators facing the anode current collector and the single second end plate facing the anode current collector are spirally arranged from the center of each separator and the second end plate. Is formed, the fuel gas flows spirally along the slits, and the reaction path of the fuel gas becomes longer. As a result, the number of collisions between the fuel gas and the fuel electrode layer increases, and the output of the fuel cell can be improved. Further, the surfaces of the n separators facing the anode current collector and the single second
By forming a plurality of slits radially extending from the center of each separator and the second end plate on the surface of the end plate facing the fuel electrode current collector, the fuel gas flows radially along the slits, Is relatively long. As a result, the number of collisions between the fuel gas and the fuel electrode layer becomes relatively large, and the output of the fuel cell can be improved. Also, a plurality of the n sheets of separators are provided radially from the center of each separator and the first end plate on the surface facing the oxidizer electrode current collector and the surface of the single first end plate facing the oxidizer electrode current collector. If each slit is formed, the oxidant gas flows radially along the slit,
The reaction path of the oxidizing gas becomes relatively long. As a result, the number of collisions between the oxidizing gas and the oxidizing electrode layer becomes relatively large,
The output of the fuel cell can be improved.

A fuel electrode current collector made of nickel-plated stainless steel or the like is joined to a separator made of stainless steel or the like and the second end plate, and an oxidizer electrode current collector made of silver-plated stainless steel or the like is formed. When the separator and the first end plate are joined to the separator and the first end plate made of stainless steel or the like, even if the separator and the first end plate are exposed to the oxidant gas at a high temperature, the joint between the separator and the oxidant electrode current collector and the first end plate can be formed. Since the welded portions of the plate and the oxidant electrode current collector are welded, oxidation of these welded portions can be prevented. As a result, the electrical continuity between the separator and the anode current collector, the electrical continuity between the second end plate and the anode current collector, as well as the electrical continuity between the separator and the oxidant electrode current collector, The electrical continuity between the end plate and the oxidant electrode current collector can be maintained for a long period of time through the joining portion, and the assembling work time of the fuel cell can be shortened and the assembling workability can be improved. In addition, if the surfaces of each separator, the first end plate and the second end plate are plated with nickel or the like, the separator, the first end plate or the second end plate, and the fuel electrode current collector or the oxidant electrode current collector Electrical continuity can be maintained for a longer period. Furthermore, if the fuel supply passage is filled with the reformed particles at a density at which the fuel gas can flow, the fuel gas is reformed by the reformed particles in the fuel supply passage. A vessel is not required. As a result, the number of parts can be reduced, and the size of the fuel cell can be reduced.

[Brief description of the drawings]

FIG. 1 is a sectional view taken along line AA of FIG. 2 showing a solid oxide fuel cell according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB of FIG. 1;

FIG. 3 is a sectional view taken along line CC of FIG. 1;

FIG. 4 is a sectional view taken along line DD of FIG. 1;

FIG. 5 is a sectional view taken along line EE of FIG. 6, showing a second embodiment of the present invention.

FIG. 6 is a sectional view taken along line FF of FIG. 5;

FIG. 7 is a sectional view taken along line GG of FIG. 5;

FIG. 8 is a sectional view taken along line HH of FIG. 7;

FIG. 9 is an exploded perspective view of a main part of a fuel cell including the power generation cell, the anode current collector, the cathode current collector, and a separator.

[Description of Signs] 10,50 Solid oxide fuel cell 11 Power generation cell 11a Solid electrolyte layer 11b Fuel electrode layer 11c Air electrode layer (oxidant electrode layer) 12,52 Separator 12a, 52a, 61a, 62a Insertion hole 12b, 22b, 52b, 61b, 62b Slit 13 Fuel electrode current collector 14 Air electrode current collector (oxidizer electrode current collector) 16, 26, 56, 66 Fuel supply passage 17, 27, 57, 67 Air supply passage (oxidation 17a, 57a, 67a First air hole (first oxidant hole) 17b, 27b, 57b, 67b Second air hole (second oxidant hole) 17c, 27c, 57c, 67c Third air hole ( Third oxidant hole) 21, 61 First end plate 22, 62 Second end plate 23, 63 Heater

Claims (19)

[Claims] 1. A solid electrolyte layer (11a) formed of an oxide ion conductor and a fuel electrode layer (11b) and an oxidizer electrode layer (11c) disposed on both surfaces of the solid electrolyte layer (11a). A solid oxide fuel cell in which (n + 1) (n is a positive integer) power generation cells (11) are stacked, and the i-th (i = 1, 2,..., N) The fuel electrode layer (11b) of the power generation cell (11) and (i + 1) adjacent to the fuel electrode layer (11b)
A total of n sheets of separators (12) formed of a conductive material are interposed between the oxidant electrode layer (11c) of the i-th power generation cell (11) and the i-th power generation cell. A porous anode current collector (13) having conductivity between the anode layer (11b) of the cell (11) and the j-th (j = 1, 2,..., N) separator (12) The oxidant electrode layer (11c) of the (i + 1) -th power generation cell (11) is interposed.
And the j-th separator (12), a porous oxidant electrode current collector (14) having conductivity is interposed, and the oxidant electrode layer (11c) of the first power generation cell (11) is provided. ) Is laminated with a single first end plate (21) made of a conductive material via an oxidant electrode current collector (14), and the (n + 1) -th power generation cell (11) A single second end plate (22) formed in a plate shape of a conductive material is laminated on the fuel electrode layer (11b) via a fuel electrode current collector (13), and the n separators (12) Separator for fuel gas (12)
A fuel supply passageway (16) which is introduced from the outer peripheral surface and flows to the approximate center while meandering, and is discharged from the approximate center of the separator (12) toward the anode current collector (13); and The separator (12) is introduced from the outer peripheral surface and flows inside the separator (12) while meandering, and the separator (12)
An oxidant supply passage (17) for discharging the oxidant gas from a surface facing the oxidant electrode current collector (14), wherein the single first end plate (21) supplies oxidant gas to the first end plate. (2
1) The first end plate (21) while being introduced from the outer peripheral surface and meandering
An oxidant supply passage (27) for flowing through the inside and discharging from the surface of the first end plate (21) facing the oxidant electrode current collector (14), wherein the single second end plate (22 ) Supplies fuel gas to the second end plate (22).
A fuel supply passage (26) that is introduced from the outer peripheral surface, flows around the center while meandering, and discharges from the substantially center of the second end plate (22) toward the anode current collector (13). Characteristic solid oxide fuel cell. 2. Each of the oxidant supply passages (17) formed in the n number of separators (12) introduces an oxidant gas from the outer peripheral surface of the separator (12) and oxidizes the separator (12) while meandering. An oxidizing agent supply passage (27) formed in a single first end plate (21) is formed so as to be discharged almost uniformly in a shower form from a surface facing the electrode current collector (14). The oxidant electrode current collector (14) of the first end plate (21) is introduced while introducing the agent gas from the outer peripheral surface of the first end plate (21) and meandering.
2. The solid oxide fuel cell according to claim 1, wherein the solid oxide fuel cell is configured to be discharged almost uniformly in a shower shape from a surface facing the fuel cell. 3. A single first oxidant hole (17a) formed in an n number of separators (12) with an oxidant supply passage (17) formed in the outer peripheral surface of each separator (12). A single second oxidant hole (17b) communicating with one oxidant hole (17a) and meandering in the separator (12); and an oxidant electrode current collector (1) of the separator (12).
A plurality of third oxidizing holes (17c) formed at predetermined intervals on the surface facing 4) and communicating with the second oxidizing holes (17b); A single first oxidant hole (27a) having an oxidant supply passage (27) formed in the end plate (21) opened on the outer peripheral surface of the first end plate (21); (27a) and a single second oxidizer hole (27b) meandering in the first end plate (21) and the oxidizer electrode current collector (14) of the first end plate (21). 3. The solid oxide fuel according to claim 2, comprising a plurality of third oxidant holes (27c) formed at predetermined intervals on the opposing surface and communicating with the second oxidant holes (27b). battery. 4. A single first oxidant hole (57a) formed in an n number of separators (52) with an oxidant supply passage (57) formed in the outer peripheral surface of each separator (52). A single second oxidizing agent hole (57b) communicating with the one oxidizing agent hole (57a) and meandering in the separator (52) toward the center, and a second oxidizing agent hole (57b)
And a single third oxidant hole (57c) facing the center of the oxidant electrode current collector (14), and an oxidant supply passage formed in the first end plate (61). 67) is a single first oxidizer hole (67) opening on the outer peripheral surface of the first end plate (61).
a) with the first oxidant hole (67a).
1) A single second oxidizer hole (6
7b) and a single third oxidant hole (67c) communicating with the second oxidant hole (67b) and substantially at the center of the oxidant electrode current collector (14).
The solid oxide fuel cell according to claim 1, comprising: 5. The n separators (12), the single first end plate (21) and the n-th separator (12) so as not to communicate with any of the fuel supply passages (16, 26) and the oxidant supply passages (17, 27). Single second end plate (22)
A plurality of insertion holes (12a, 21a, 22a) are formed in each of the
The solid oxide fuel cell according to any one of claims 1 to 4, wherein a heater (23) or a heater (23) and a temperature sensor are respectively inserted into the plurality of insertion holes (12a, 21a, 22a). 6. An n number of separators and a single first separator so as not to communicate with any of the fuel supply passage and the oxidant supply passage.
5. The solid oxide fuel cell according to claim 1, wherein a plurality of lightening holes are formed in each of the end plate and the single second end plate. 7. An anode current collector (1) of n separators (12).
3) and the anode current collector (1) of the single second end plate (22).
7. A plurality of slits (12b, 22b) spirally extending from the center of each separator (12) and the second end plate (22) are formed on the surface facing 3), respectively. Solid oxide fuel cell. 8. An anode current collector (1) of n separators (52).
3) and the anode current collector (1) of the single second end plate (62).
The solid according to any one of claims 1 to 6, wherein a plurality of slits (52b, 62b) extending radially from the center of each separator (52) and the second end plate (62) are formed on the surface facing 3). Oxide fuel cell. 9. An oxidant electrode current collector for n separators (52).
The separator (52) and the first end plate (6) are provided on the surface facing the oxidant electrode current collector (14) of the single first end plate (61) and the single end plate (61).
Multiple slits (52b, 61b) extending radially from the center of 1)
The solid oxide fuel cell according to any one of claims 1 to 8, wherein is formed. 10. The anode current collector (13) is nickel-plated,
Silver- or copper-plated stainless steel, nickel-based alloy or chromium-based alloy, or stainless steel formed of nickel, silver or copper, and oxidant electrode current collector (14) plated with silver or platinum, nickel-based Alloy or chromium-based alloy, or silver or platinum, n separators (12), single first end plate (21) and single second end plate (22) are made of stainless steel, nickel-based alloy Alternatively, the anode current collector (13) is formed of a chromium-based alloy, and the anode current collector (13) is joined to each of the separators (12) and the second end plate (22). The first separator (12) and the first end plate (21) are respectively joined to the first end plate (21).
The solid oxide fuel cell according to any one of the above. 11. The surface of n separators, a single first
The solid oxide fuel cell according to any one of claims 1 to 10, wherein a surface of the end plate and a surface of the single second end plate are plated with nickel, chromium, or silver, respectively. 12. The solid oxide fuel cell according to claim 1, wherein the fuel supply passage is filled with the modified particles at a density at which a fuel gas can flow. 13. The modified particles may be Ni, NiO, Al ₂ O ₃ ,
SiO ₂ , MgO, CaO, Fe ₂ O ₃ , Fe ₃ O ₄ , V ₂ O
₃ , NiAl ₂ O ₄ , ZrO ₂ , SiC, Cr ₂ O ₃ , ThO
₂ , Ce ₂ O ₃ , B ₂ O ₃ , MnO ₂ , ZnO, Cu, BaO
And one or element, or a solid oxide fuel cell according to claim 12 wherein formed by an oxide containing two or more selected from the group consisting of TiO _2. 14. An oxidant supply passage (17) in which an oxidant gas is introduced from an outer peripheral surface and meandered so as to be discharged almost uniformly in a shower form from a surface facing the oxidant electrode current collector (14). Composed separator. 15. An oxidant supply passage (27) in which an oxidant gas is introduced from the outer peripheral surface and meandered so as to be discharged almost uniformly in a shower form from a surface facing the oxidant electrode current collector (14). The configured first end plate. 16. A single first oxidizing agent hole (17a) having an oxidizing agent supply passage (17) opened on the outer peripheral surface, and the first oxidizing agent hole (17a).
A second oxidizing agent hole (17b) that is meandering and meanders, and a predetermined interval is provided between the surface facing the oxidant electrode current collector (14) and communicates with the second oxidizing agent hole (17b). 15. The separator according to claim 14, having a plurality of third oxidant holes (17c) formed so as to form the third oxidant hole. 17. A single first oxidant hole (27a) having an oxidant supply passage (27) opened on the outer peripheral surface, and the first oxidant hole (27a).
A second oxidizing agent hole (27b) communicating with and meandering, and a predetermined interval on a surface facing the oxidant electrode current collector (14) and communicating with the second oxidizing agent hole (27b). 16. The first end plate according to claim 15, having a plurality of third oxidant holes (27c) formed so as to be formed. 18. A fuel electrode current collector (1) is introduced from a substantially center while a fuel supply passage (16) introduces fuel gas from an outer peripheral surface and meanders.
A separator configured to discharge toward 3). 19. A fuel supply passage (26) introduces fuel gas from the outer peripheral surface and meanders the fuel gas from substantially the center thereof.
A second end plate configured to discharge toward 3).