JP2000182653A - Solid electrolyte fuel cell block and solid electrolyte fuel cell module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell module using interconnectorless SOFC's capable of taking out a generated power of high voltage and small current. SOLUTION: A specified number of interconnectorless solid electrolyte fuel cells 100 are accommodated in a power generation chamber 11, and a fuel exhaust chamber 15 and fuel supply chamber 14 are formed over the power generation chamber while an air supply chamber 18 is formed under the power generation chamber, and their periphery is enwrapped with a heat insulating material 19, and the air electrodes are connected electrically with the respective air electrode side collector members 31 arranged under the power generation chamber while conductive connecting rods 106 are connected with the upper parts of fuel supply pipes, and thus an intended fuel cell block 10 is accomplished. A plurality of such blocks 10 are piled up in stages, and the connecting rods 106 of the lower fuel cell block 10 are inserted in corresponding recesses 33 formed at the bottoms of the air electrode side collector members 31 of the upper fuel cell block 10 so that series connection is generated, and thus assembly of a fuel cell module is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a solid oxide fuel cell block and a solid oxide fuel cell module using an interconnectless solid oxide fuel cell.

[0002]

2. Description of the Related Art In recent years, solid oxide fuel cells (SOF)
The development of a solid oxide fuel cell module applicable to the practical device of C) is underway. JP-A-10-01225
No. 8 proposes an internal reforming solid oxide fuel cell module. In this conventional solid oxide fuel cell module, a reforming reaction between fuel gas and steam is performed in the module without providing an external reforming reactor, and then the fuel gas is supplied to the fuel cell stack and used for power generation. It is assumed that.

In this conventional solid oxide fuel cell module, a vertical stripe type solid oxide fuel cell having an interconnector 1 as shown in FIG. 6 is used for each solid oxide fuel cell. In a vertical stripe type solid electrolyte fuel cell having this interconnector, an air electrode 3, a solid electrolyte 4, and a fuel electrode 5 are sequentially provided outside a porous substrate tube 2 by EVD.
The interconnector 1 is buried in a manner insulated from the fuel electrode 5 for serial connection with an adjacent solid oxide fuel cell by stacking the interconnector 1 in the air electrode 3 in the inner layer. It is a connected structure.

[0004]

However, in the case of a solid electrolyte fuel cell module employing a vertical stripe type solid electrolyte fuel cell having such an interconnect,
There is a difference in the material at the boundary between the fuel electrode 5, the solid electrolyte 4, and the interconnector 1.
Since power is generated under a high temperature condition of 00 to 1000 ° C., there is a problem that breakage easily occurs due to a difference in coefficient of thermal expansion.

[0005] To cope with this, a technology for constructing a fuel cell module using an interconnect-less solid oxide fuel cell has been developed. In order to electrically connect the batteries, a technology that replaces the conventional interconnector is required. Also, since the electromotive force of a single fuel cell is small, a large number of fuel cells are stacked,
In addition, it is necessary to connect a plurality of stages in series as much as possible to suppress the loss due to the internal resistance and to extract a large amount of power.

SUMMARY OF THE INVENTION The present invention has been made to solve such a technical problem, and uses a solid electrolyte fuel cell without an interconnector to efficiently generate electric power. It is an object to provide a block and a solid oxide fuel cell module.

[0007]

According to a first aspect of the present invention, there is provided a solid oxide fuel cell block in which an air electrode, a solid electrolyte, and a fuel electrode are stacked in order from the outside to the inside, and a fuel collector / collector is provided inside the fuel electrode. A predetermined number of interconnector-less solid oxide fuel cells into which a supply pipe is inserted are housed in a power generation chamber, and a fuel discharge chamber and a fuel supply chamber are formed above the power generation chamber, and below the power generation chamber. Forming an air supply chamber, surrounding each of the chambers with a heat insulating material, electrically connecting each of the air electrodes to an air electrode side current collecting member disposed at a lower portion of the power generation chamber, A conductive connecting rod was joined to the upper part of each supply pipe, and a fitting part for inserting an upper end of the conductive connecting rod and electrically connecting the conductive connecting rod to the bottom surface of the air electrode side current collecting member was formed. Things.

In the solid electrolyte fuel cell block according to the first aspect of the present invention, the solid electrolyte fuel cell blocks are stacked in a plurality of stages, and the upper ends of the conductive connecting rods respectively joined to the fuel supply pipes of the lower solid electrolyte fuel cell blocks. The solid electrolyte fuel cell module is simplified by inserting each part into the fitting part formed on the bottom surface of each air electrode side current collecting member of the solid electrolyte fuel cell block on each upper side and electrically connecting them in series. In addition, the internal loss of the generated power can be reduced and the power can be efficiently extracted.

According to a second aspect of the present invention, in the solid oxide fuel cell block according to the first aspect of the present invention, the air electrode-side current collecting member is formed of a LaMnO-based oxide, and is provided on a bottom surface of the air electrode-side current collecting member. A protective layer of LaCrO-based oxide is formed on the inner peripheral surface of the formed fitting portion, and the conductive connecting rod is made of SUS,
It is made of a dense material of Ni or Ni-based alloy, and suppresses the occurrence of cracks and cracks in each part due to the difference in the coefficient of thermal expansion in fuel cell power generation under high temperature conditions. To withstand.

In the solid oxide fuel cell block according to the third aspect of the present invention, an air electrode, a solid electrolyte, and a fuel electrode are stacked in order from the inside to the outside, and an air supply pipe serving both as a current collector is inserted inside the air electrode. A predetermined number of interconnect-less solid oxide fuel cells are housed in a power generation chamber, an air supply chamber and an air discharge chamber are formed above the power generation chamber, and a fuel supply chamber is formed below the power generation chamber. Surrounding each of the chambers with a heat insulating material, electrically connecting each of the fuel electrodes to a fuel electrode side current collecting member disposed at a lower portion of the power generation chamber, and electrically connecting the fuel electrodes to an upper portion of each of the air supply pipes. And a fitting part for inserting an upper end of the conductive connecting rod and electrically connecting the conductive connecting rod to the fuel electrode side current collecting member.

In the solid electrolyte fuel cell block according to the third aspect of the present invention, the solid electrolyte fuel cell blocks are stacked in a plurality of stages, and the upper ends of the conductive connecting rods joined to the respective air supply pipes of the lower solid electrolyte fuel cell blocks. The solid electrolyte fuel cell module can be simplified by inserting each part into each fitting part formed on the bottom surface of each fuel electrode side current collecting member of the solid electrolyte fuel cell block on the upper side and electrically connecting them in series. In addition, the internal loss of the generated power can be reduced and the power can be efficiently extracted.

According to a fourth aspect of the present invention, in the solid oxide fuel cell block according to the third aspect of the present invention, the fuel electrode side current collecting member is formed of a Ni-based material and formed on the bottom surface of the air electrode side current collecting member. A protective layer of LaCrO-based oxide is formed on the inner peripheral surface of the fitting portion thus formed, and the conductive connecting rod is formed of a dense material of SUS, Ni or Ni-based alloy which has been subjected to oxidation-resistant surface. In addition, cracks and cracks are suppressed from being generated in each part due to the difference in the coefficient of thermal expansion in the fuel cell power generation under high temperature conditions, and the device can withstand long-term use.

According to a fifth aspect of the present invention, there is provided a solid oxide fuel cell module according to the first or second aspect, wherein the solid oxide fuel cell blocks according to the first or second aspect are stacked in a plurality of stages. The upper ends of the conductive connecting rods joined to the respective fuel supply pipes are inserted into respective fitting portions formed on the bottom surfaces of the air electrode side current collecting members of the solid oxide fuel cell blocks on the upper side, respectively, to thereby supply electricity. Are connected in series, so that the internal loss of the generated power can be reduced and the power can be extracted efficiently.

According to a sixth aspect of the present invention, there is provided a solid oxide fuel cell module wherein the solid oxide fuel cell blocks according to the third or fourth aspects are stacked in a plurality of stages, and each of the solid electrolyte fuel cell blocks on the lower side is provided. The upper ends of the conductive connecting rods joined to the respective air supply pipes are inserted into respective fitting portions formed on the bottom surfaces of the fuel electrode side current collecting members of the solid electrolyte fuel cell blocks on the upper side, respectively, and electric power is supplied. Are connected in series, so that the internal loss of the generated power can be reduced and the power can be extracted efficiently.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. 1 to 3 show one embodiment of the present invention. The solid oxide fuel cell block 10 having the structure shown in FIG. 1 accommodates a predetermined number, for example, several to several tens, of the solid electrolyte fuel cells 100 having no interconnector structure shown in FIG. , This power generation room 1
A fuel discharge chamber 14 and a fuel supply chamber 15 are formed by installing insulating partition members 12 and 13 above the grid 1, a grid 16 is installed below the power generation chamber 11, and an insulating partition member is further provided below the grid 16. 17 are provided to form an air supply chamber 18, and these solid oxide fuel cells 1
00 and a heat insulating material 19 around each of the chambers 11, 14, 15, and 17.
The structure is surrounded by. In addition, the heat insulating material 19 has a shape that can be stacked in multiple layers vertically.

A fuel supply pipe 21 for supplying a fuel gas 20 is connected to the fuel supply chamber 14, and a fuel exhaust gas and unreacted gas are discharged to the outside as a discharged fuel gas 22 to a fuel discharge chamber 15. Exhaust pipe 23 is connected to the fuel tank. On the other hand, an air supply pipe 25 for supplying an oxidizing gas 24 is connected to the air supply chamber 17, and an air discharge pipe 27 for a discharged oxidizing gas 26 is connected to the power generation chamber 11.

As shown in FIG. 4, the solid oxide fuel cell 100 used in this embodiment has a fuel electrode 101, a solid electrolyte 102, and an air electrode 103 which are formed in this order from the inside, and the fuel is ejected to the center. For this purpose, the fuel supply pipe 104 for collecting current, which has a porous portion facing the fuel electrode 101, is inserted.
A conductive nickel felt 105 having a fuel reforming function is filled between the fuel supply pipe 104 and the fuel electrode 101, and the fuel gas 20 is supplied to the fuel supply pipe 104, and the oxidizing gas 24 flows around the outer circumference. The structure is as described above. The length of the power generation section of the solid oxide fuel cell 100 is about 10 to 30 cm so that multi-stage stacking is possible. The fuel supply pipe 104 is made of SUS, Ni or a Ni-based alloy, and a solid SUS conductive connecting rod 106 is connected to the upper end of the fuel supply pipe 104.

As shown in FIG. 1, the upper end of the air electrode 101 which forms the outermost shell of each of the solid oxide fuel cells 100 is fixed to an insulating partition member 13 which separates the power generation chamber 11 and the fuel discharge chamber 15 from each other. The fuel supply pipe 104 of each solid oxide fuel cell 100 is supported by a fuel discharge chamber 15.
The fuel supply chamber 14 is fixed and supported by an insulating partition member 12 which partitions the fuel supply chamber 14. The portion of the conductive connecting rod 106 above the fuel supply pipe 104 has a length protruding above the heat insulating material 19.

Next, the electrical connection structure will be described.
As shown in detail in FIG.
On the top, LaSrMnO that supports and electrically connects the bottom of the air electrode 101 that forms the outer shell of each fuel cell 100
An air electrode side current collecting member 31 made of a system oxide is provided.
Pt paste 32 between them to improve conductivity
Is inserted. A concave portion 33 as a fitting portion is formed on the bottom surface side of the air electrode side current collecting member 31, and a protective layer made of LaSrCrO-based oxide is formed on the inner peripheral surface thereof. The inner diameter of the recess 33 is set to a size substantially matching the outer diameter of the conductive connecting rod 106 projecting upward from the lower fuel cell block 10, and the conductive connecting rod 106
It is a setting that can be electrically connected by inserting the upper end of the.

As shown in FIG. 3, the solid oxide fuel cell block 10 having the above-described structure is assembled in multiple stages by the number of stages required for the output power, thereby assembling a solid oxide fuel cell module. In this stacking, the upper ends of the conductive connecting rods 106 protruding upward from the lower fuel cell blocks 10 are respectively inserted into the recesses 33 of the air electrode side current collecting member 31 of each upper fuel cell block 10. Insert Thus, simultaneously with the multi-stage lamination, the air electrode of the lowermost fuel cell block 10 located on the same vertical line to the fuel supply pipe 104 of the uppermost fuel cell block 10 are connected in series. Therefore, when the electromotive voltage V of each fuel cell 100 alone is N and the number of stages is N, the electromotive voltage of the entire fuel cell 100 connected on each vertical line is N × V.

Next, the power generation operation of the solid oxide fuel cell module having the above configuration will be described. For each solid oxide fuel cell block 10 shown in FIG. 1, fuel gas 20 is supplied to the fuel supply chamber 14, supplied from each fuel supply pipe 104 into each solid oxide fuel cell 100, and used for power generation. You. After being used for power generation, the fuel discharge chamber 1
And is exhausted out of the system as exhaust fuel 22.
On the other hand, the oxidizing gas 24 is supplied from the air supply chamber 18 to the grid 1.
6 and is supplied to the power generation chamber 11. Here, the oxidizing gas 24 is used for power generation in the power generation chamber 11, and thereafter, the discharged oxidizing gas 26 is collected in the air discharge pipe 27 and exhausted to the outside.

How to set the final output of the generated power depends on the application. As an example, several to several 1 are accommodated in the solid oxide fuel cell block 10.
The zero fuel cells 100 are divided into one or more groups,
The air electrode side current collecting members 31 of the fuel cells 100 belonging to each group in the lowermost fuel cell block 10 are connected in parallel in advance, and the fuel of the fuel cells 100 belonging to the same group in the uppermost fuel cell block 10 is also connected. The supply pipes 104 are connected in parallel in advance, and the power take-out terminals 41 and 42 are connected to each group to take out power outside. As a result, it is possible to take out DC power of appropriate electromotive voltage and current.

For example, the number of fuel cells belonging to one group is M in each fuel cell block 10, and the number of stages connected in series is N in the same manner as described above.
Assuming the current I, the output voltage in one group is N × V, and the output current is M × I.

When L groups are provided in one fuel cell module, the output voltage of the whole fuel cell module is N × V × by connecting the power extraction terminals 41 and 42 of each group in series. L, output current is M
× I. Conversely, the current extraction terminals 4 for each group
1 and 42, the output voltage of one fuel cell module as a whole is N × V and the output current is M × I ×
L. Therefore, the power extraction terminals 4 of each group
The output voltage Vo and the output current Io are respectively N × V × L ≧ Vo ≧ N × V; M ×
An appropriate output can be taken out in the range of I ≦ Io ≦ M × I × L.

In this manner, the solid oxide fuel cell block 10 of this embodiment can easily assemble a solid oxide fuel cell module by multi-layer stacking. Even if the electrolyte type fuel cell 100 is used, DC power of an appropriate voltage can be taken out, and since a fuel cell without an interconnector can be used, the difference in thermal expansion coefficient between the fuel cell itself and the high temperature condition during power generation can be obtained. It is less susceptible to damages due to, and long-term continuous operation is possible.

In the above embodiment, as shown in FIG. 4, a solid oxide fuel cell 100 having an air electrode 101 on the outside and a fuel electrode 103 on the inside is used.
As shown in the figure, the laminated structure is opposite to this, the fuel electrode 111, the solid electrolyte 112, and the air electrode 113 are arranged in this order from the outside, and the air supply pipe 114 is inserted into the air electrode 113 as a base tube. A solid oxide fuel cell 110 can also be used. In this case, unlike the structure of the solid oxide fuel cell block 10 of the embodiment shown in FIGS. 1 and 2, the fuel gas 20 and the oxidizing gas 24 supply system is reversed. . That is,
In the fuel cell block 10 shown in FIG. 1 and FIG.
The fuel supply chamber 14 serves as an air supply chamber, the fuel discharge chamber 15 serves as an air discharge chamber, and the lower air supply chamber 18 serves as a fuel supply chamber to introduce fuel gas 20 into the power generation chamber 11. Further, the conductive connecting rod 106 is connected to the upper part of the air supply pipe 114, and the fuel electrode side current collecting member is provided at the same place instead of the air electrode side current collecting member 31. However, insulation 19
And the structure for assembling the solid oxide fuel cell module by multi-stacking shown in FIG. 3 is basically the same.

[0027]

As described above, according to the solid oxide fuel cell block of the first aspect of the present invention, the solid oxide fuel cell blocks are stacked in a plurality of stages and joined to the respective fuel supply pipes of the lower solid oxide fuel cell blocks. By inserting the upper end portions of the conductive connecting rods into the fitting portions formed on the bottom surfaces of the air electrode side current collecting members of the solid oxide fuel cell blocks on the upper side, respectively, and electrically connecting them in series. The solid oxide fuel cell module can be easily assembled, and the internal loss of the generated electric power can be reduced and the electric power can be efficiently extracted.

According to the solid oxide fuel cell block of the second aspect of the invention, in addition to the effect of the first aspect, the air electrode side current collecting member is formed of LaMnO-based oxide, and La on the inner peripheral surface of the fitting portion formed on the bottom surface of the electrical member
A protective layer of CrO-based oxide is formed, and the conductive connecting rod is made of SU.
Since it is formed of a dense material of S, Ni or a Ni-based alloy, it is possible to suppress the occurrence of breakage in each part due to the difference in the coefficient of thermal expansion in fuel cell power generation under high temperature conditions, and to use it for a long time. To withstand.

According to the solid electrolyte fuel cell block of the third aspect of the present invention, the solid electrolyte fuel cell blocks are stacked in a plurality of stages, and the conductive connecting rods are joined to the respective air supply pipes of the lower solid electrolyte fuel cell blocks. The solid electrolyte fuel cell module is inserted by inserting each upper end of the solid electrolyte fuel cell block into a fitting portion formed on the bottom surface of each fuel electrode side current collecting member of each upper solid fuel cell block and electrically connecting them in series. Can be easily assembled, the internal loss of the generated power can be reduced, and the power can be extracted efficiently.

According to the solid oxide fuel cell block of the invention of claim 4, in addition to the effect of the invention of claim 3, the fuel electrode side current collecting member is formed of a Ni-based material, A dense material of SUS, Ni or Ni-based alloy in which a protective layer of LaCrO-based oxide is formed on the inner peripheral surface of the fitting portion formed on the bottom surface of the member, and the surface of the conductive connecting rod is subjected to oxidation resistance treatment. Therefore, it is possible to suppress the occurrence of breakage in each part due to the difference in the coefficient of thermal expansion in fuel cell power generation under high temperature conditions, and to endure long-term use.

According to the solid oxide fuel cell module of the fifth invention, the solid oxide fuel cell blocks of the first or second invention are stacked in a plurality of stages, and each solid electrolyte fuel cell block on the lower side is stacked. The upper ends of the conductive connecting rods joined to the respective fuel supply pipes are respectively inserted into fitting portions formed on the bottom surfaces of the air electrode side current collecting members of the solid oxide fuel cell blocks on the upper side. And the structure is electrically connected in series, so its assembly is easy,
Further, the internal loss of the generated power can be reduced and the power can be efficiently extracted.

According to the solid oxide fuel cell module of the sixth aspect, the solid oxide fuel cell block of the third or fourth aspect is stacked in a plurality of stages, and each solid electrolyte fuel cell block on the lower side is stacked. The upper ends of the conductive connecting rods joined to the respective air supply pipes are respectively inserted into fitting portions formed on the bottom surfaces of the fuel electrode side current collecting members of the solid electrolyte fuel cell blocks on the upper side. And the structure is electrically connected in series, so its assembly is easy,
Further, the internal loss of the generated power can be reduced and the power can be efficiently extracted.

[Brief description of the drawings]

FIG. 1 is a structural sectional view of a solid oxide fuel cell block according to one embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view showing an electrical connection structure between fuel cells between upper and lower solid oxide fuel cell blocks in the embodiment.

FIG. 3 is an exploded front view of a solid oxide fuel cell module configured by stacking the solid oxide fuel cell blocks of the above embodiment in multiple stages.

FIG. 4 is a cross-sectional view of a solid oxide fuel cell used in the above embodiment.

FIG. 5 is a cross-sectional view of a solid oxide fuel cell used in another embodiment of the present invention.

FIG. 6 is a perspective view of a conventional solid oxide fuel cell.

[Explanation of symbols]

 Reference Signs List 10 fuel cell block 11 power generation chamber 12 insulating partition member 13 insulating partition member 14 fuel supply chamber 15 fuel discharge chamber 16 grid 17 insulating partition member 18 air supply chamber 19 heat insulating material 20 fuel gas 21 fuel supply pipe 22 discharged fuel 23 Fuel discharge pipe 24 Oxidizing gas 25 Air supply pipe 26 Discharged oxidizing gas 27 Air discharge pipe 31 Air electrode side current collecting member 32 Pt paste 33 Concave part 34 Protective layer 41 Power extraction terminal 42 Power extraction terminal 100 Solid oxide fuel cell 101 Air electrode 102 Solid electrolyte 103 Fuel electrode 104 Fuel supply pipe 105 Conductive nickel felt 106 Conductive connecting rod 110 Solid electrolyte fuel cell 111 Fuel electrode 112 Solid electrolyte 113 Air electrode 114 Air supply pipe

Continuing from the front page (72) Inventor Masayoshi Nishimura 3-3-22 Nakanoshima, Kita-ku, Osaka-shi, Osaka Inside Kansai Electric Power Company (72) Inventor Riki Iwasawa 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Co., Ltd. (72) Inventor Masataka Mochizuki 1-5-1 Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Masakatsu Nagata 1-5-1 Kiba, Koto-ku, Tokyo F-Terminal Co., Ltd. F-term (reference) 5H026 AA06 CC06 CV02 CV08 CX06 CX09 CX10 EE02 EE08 EE13

Claims (6)

[Claims] 1. An interconnector-less solid electrolyte fuel cell in which an air electrode, a solid electrolyte, and a fuel electrode are laminated in order from the outside to the inside, and a fuel supply pipe for current collection is inserted inside the fuel electrode. Several bodies are accommodated in a power generation chamber, a fuel discharge chamber and a fuel supply chamber are formed above the power generation chamber, an air supply chamber is formed below the power generation chamber, and the periphery of each of these chambers is covered with a heat insulating material. Surrounding, electrically connecting each of the air electrodes to an air electrode side current collecting member arranged at a lower portion of the power generation chamber, joining a conductive connecting rod to an upper portion of each of the fuel supply pipes, A solid oxide fuel cell block in which a fitting portion for inserting an upper end of the conductive connecting rod and electrically connecting the conductive connecting rod is formed on a bottom surface of the current collecting member. 2. The air electrode-side current collecting member is made of LaMnO-based oxide, and a LaCrO-based oxide protective layer is formed on an inner peripheral surface of a fitting portion formed on a bottom surface of the air electrode-side current collecting member. The solid oxide fuel cell block according to claim 1, wherein the conductive connecting rod is formed of a dense material of SUS, Ni, or a Ni-based alloy. 3. A predetermined solid electrolyte fuel cell without an interconnector, wherein an air electrode, a solid electrolyte, and a fuel electrode are stacked in order from the inside to the outside, and an air supply pipe for current collection is inserted inside the air electrode. Several bodies are accommodated in a power generation chamber, an air supply chamber and an air discharge chamber are formed above the power generation chamber, a fuel supply chamber is formed below the power generation chamber, and the periphery of each of these chambers is surrounded by a heat insulating material. Electrically connecting each of the fuel electrodes to a fuel electrode-side current collecting member disposed at a lower portion of the power generation chamber; joining a conductive connecting rod to an upper portion of each of the air supply pipes; A solid oxide fuel cell block in which a fitting portion for inserting an upper end portion of the conductive connecting rod and electrically connecting the conductive connecting rod is formed on a bottom surface of the electric member. 4. The fuel electrode-side current collecting member is formed of a Ni-based material, and a LaCrO-based oxide protective layer is formed on an inner peripheral surface of a fitting portion formed on a bottom surface of the air electrode-side current collecting member. SUS wherein the surface of the conductive connecting rod is subjected to an oxidation-resistant treatment,
The solid oxide fuel cell block according to claim 3, wherein the solid electrolyte fuel cell block is formed of a dense material of Ni or a Ni-based alloy. 5. A conductive connecting rod which is formed by stacking the solid oxide fuel cell blocks according to claim 1 or 2 in a plurality of stages and joined to the fuel supply pipes of each lower solid oxide fuel cell block. Solid-state fuel cells, each having an upper end portion inserted into a fitting portion formed on the bottom surface of each of the air electrode-side current collecting members of the upper solid oxide fuel cell block and electrically connected in series. module. 6. A conductive connecting rod which is formed by laminating the solid oxide fuel cell blocks according to claim 3 or 4 in a plurality of stages, and which is joined to each of the air supply pipes of each lower solid oxide fuel cell block. Solid-state fuel cells, each having an upper end inserted into a fitting portion formed on the bottom surface of each of the fuel-electrode-side current collecting members of the upper solid oxide fuel cell block and electrically connected in series. module.