JPH10125346A - Cylindrical solid oxide fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To stably operate a fuel cell by eliminating the possibility of peeling of the electrolyte layers and electrode layers of each unit cell, even when receiving a large heat cycle. SOLUTION: A fuel electrode layer 13, made of Ni-ZrO2 , a solid electrolyte layer 14 made of ZrO2 , and an oxidizer electrode layer 15 made of LaMnO3 are sequentially stacked in cylindrical shapes over the outer peripheral surface of a heat-resistant metallic cylinder 12, made of Ni-Cr and closed at one end, for forming a unit cell 11. The plurality of cells 11 and separators each formed by sandwiching a nonconductive sheet between two conductive thin plates are stacked alternately to form a stack, and a fuel gas is passed into the cylinder of each cell 11 and an oxidizer gas is passed around the outer periphery of the cell 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stack structure of a cylindrical solid oxide fuel cell.

[0002]

2. Description of the Related Art FIG. 7 shows a solid oxide fuel cell having a self-standing membrane-type cylindrical vertical stripe structure, which has been evaluated as the most technically advanced among conventional solid oxide fuel cells. It is a perspective view which shows the structure of a cell. This cell 6
The first feature is that an electrolyte layer 63 and a fuel electrode layer 64 are sequentially formed in an arc shape on the outer surface of a cathode tube 62 formed of a porous cylinder also serving as an oxidant electrode, and the cathode tube is formed in a portion where the arc is cut. An interconnector layer 65 extending in the longitudinal direction of the cylinder in contact with the outer surface of the cylinder 62 is provided. An oxidant gas flows through the inside of the cylinder, and a fuel gas flows through the outer periphery of the cylinder. The reaction is such that a voltage is generated between the cathode tube 62 and the fuel electrode layer 64, and thus between the interconnector layer 65 and the fuel electrode layer 64.

FIG. 8 is a cross-sectional view of a stack formed by combining the cells having the configuration shown in FIG. As can be seen from the figure, in this stack, the cells 67 are connected in parallel and in series by connecting the cells 61 by nickel felt to form a block 67 , and these blocks 67 are assembled to form a predetermined It is configured so that voltage and current can be obtained. That is, in each block 67 , the cells 61 arranged in the horizontal direction in the figure are electrically connected in parallel by connecting the outermost fuel electrode layers 64 by the nickel felt 66, and the unit cells 61 arranged in, and the fuel electrode layer 64 of the interconnector layer 65 and the upper unit cells 61 of the lower unit cell 61 is electrically connected in series by connecting to each other by a nickel felt 68.

[0004]

The above-described fuel cell having the self-standing membrane type cylindrical vertical stripe structure is evaluated as the most technically advanced cylindrical solid oxide fuel cell at this stage as described above.
However, even in a fuel cell having this structure, when a rapid thermal cycle is applied or an overload is applied, an electrolyte layer 63, a fuel electrode layer 64, an interconnector layer formed in an arc shape on the outer surface of a cylindrical cathode tube 62. There was a problem that 65 peeled off. The cause of the peeling is that the thermal expansion coefficient of the material forming the cathode tube 62 and the thermal expansion coefficient of the material forming the electrolyte layer 63, the fuel electrode layer 64, and the interconnector layer 65 are slightly different from each other. Is applied, an internal stress is generated due to a difference in thermal expansion coefficient, and the layers are peeled off from the longitudinal ends of the arc-shaped layers. Further, when rapid heat generation occurs due to polarization at the time of overload, similar peeling occurs due to a difference in thermal expansion coefficient.

[0005] An object of the present invention is to eliminate the possibility that the electrolyte layer and the electrode layer of a single cell will be peeled off even when such a large thermal cycle occurs or when an overload causes rapid heat generation. Another object of the present invention is to provide a cylindrical solid oxide fuel cell that can operate stably.

[0006]

In order to achieve the above-mentioned object, the present invention provides: (1) an outer peripheral surface of a conductive porous cylinder having one end sealed and made of, for example, a heat-resistant metal material; Ni-ZrO ₂ fuel electrode layer made of cermet, for example, a solid electrolyte layer made of ZrO _2, for example, a unit cell of the oxidant electrode layer made of LaMnO ₃ is formed by laminating sequentially on a cylindrical, for example a refractory metal on the end portion Between two conductive thin plates made of a heat-resistant metal plate having a corrugated shape obtained by welding a rod, a separator formed by sandwiching a non-conductive sheet made of, for example, heat-resistant glass fiber felt,
A plurality of unit cells and separators arranged side by side are alternately stacked and arranged to form a stack of a cylindrical solid oxide fuel cell, and a fuel gas containing hydrogen inside a conductive porous cylinder of the unit cells, Further, an oxidizing gas containing oxygen flows through the outer periphery of the unit cell.

(2) A conductive porous material, for example, LaCrO ₃ , for example, LaMnO _{3, is provided} on the entire surface of the sealed bottom portion and the outer peripheral surface near the bottom portion with a conductive porous material, for example, LaCrO 3. the interconnector layer of ₃ to form, and, on the outer peripheral surface of the oxidizing agent electrode cylinder adjacent to the interconnector layer, for example, a solid electrolyte layer made of ZrO _2, a fuel electrode layer made of, for example, Ni-ZrO ₂ cermet A non-conductive cell made of, for example, a heat-resistant glass fiber felt is placed between a unit cell formed by sequentially laminating a cylindrical shape and two conductive thin plates made of, for example, a corrugated heat-resistant metal plate with a heat-resistant metal rod welded to an end. A plurality of unit cells and separators arranged side by side with a conductive sheet interposed therebetween are alternately stacked and arranged to form a stack of a cylindrical solid oxide fuel cell. quality An oxidizing gas is used inside the cylinder and a fuel gas is used around the outer periphery of the unit cell.

In the structure of a unit cell in which each layer is formed in an arc shape on the outer periphery of a cylinder as in the conventional example shown in FIG. 7, if the material forming each layer has a different coefficient of thermal expansion, the amount of thermal expansion increases as the temperature changes. Due to the difference, thermal stress is applied to each layer against the adhesion between the layers. Therefore, if an excessive heat cycle is applied or heat generation during an overload is excessive, the thermal stress exceeds the adhesive strength between the layers, causing delamination between the layers, and the amount of change is particularly large at the ends. Therefore, peeling is likely to occur. On the other hand, if each layer is formed in a cylindrical shape, even if the amount of thermal expansion of each layer varies with temperature change, each layer is held by the circumferential compressive force or tensile tension applied to itself, and Is uniformly dispersed in the circumferential direction, so that delamination between layers hardly occurs.

Therefore, as described in the above (1), if the unit cells are formed by sequentially stacking the respective layers on the outer peripheral surface of the conductive porous cylinder in a cylindrical shape, a large heat cycle may be caused or an excessive heat cycle may be caused. Even if heat generation under load increases, delamination between layers is avoided, and deterioration of battery characteristics is prevented. Further, even when a unit cell is formed as in the above (2), since each layer is formed in a cylindrical shape, delamination between layers is similarly avoided, and deterioration of battery characteristics is prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the cylindrical solid oxide fuel cell of the present invention will be described below with reference to examples. <Embodiment 1> FIGS. 1A and 1B are configuration diagrams of a cylindrical unit cell of a cylindrical solid oxide fuel cell according to Embodiment 1 of the present invention, wherein FIG. 1A is a perspective view, FIG. FIG. 2 is a configuration diagram of a combination of the cylindrical unit cell of Example 1 and a separator.
(A) is a cross-sectional view, (b) is a plan view seen from above (a), FIG. 3 is a cross-sectional view showing a configuration of a stack of the first embodiment, and FIG. 4 is a configuration of a module of the first embodiment. FIG. 5 is a configuration diagram of a mounting portion of a cylindrical unit cell incorporated in the module of FIG.

The manufacturing method of the cylindrical unit cell 11 shown in FIG. 1 is as follows. That is, it is manufactured by the extrusion molding method using Ni-Cr, and one end is similarly sealed with Ni-Cr to obtain a porosity of 30%.
%, Heat resistant metal cylinder 1 with outer diameter 20mm, inner diameter 10mm, length 460mm
2 from the opening end of the formed heat-resistant metal cylinder 12
The Ni-ZrO ₂ cermet is roughly (30% porosity) flame-sprayed on the entire outer peripheral surface except for the 20 mm
A μm fuel electrode layer 13 is formed. Next, ZrO ₂ is densely sprayed on the entire surface of the formed fuel electrode layer 13 and the sealed bottom by plasma spraying to form a solid electrolyte layer 14 having a thickness of 100 μm. Next, a portion 80 mm from the opening end of the surface of the formed solid electrolyte layer 14 and 80 mm from the bottom.
LaMnO _{3 is} applied to the entire surface of the 300 mm
Roughly (porosity 30%) flame sprayed to a thickness of 100 μm
Is formed, and the cylindrical unit cell 11 is manufactured.

Further, a separator having a three-layer structure shown in FIG.
The manufacturing method of No. 16 is as follows. LaMnO ₃ is densely coated by plasma spraying on both sides of a 1 mm thick, 300 mm × 300 mm thick Ni-Cr alloy plate press-formed into a corrugated form, and a 100 μm thick oxidation-resistant coating layer is applied. Heat-resistant metal plate 17 provided
To form Next, a ceramic felt 1 having a thickness of 2 mm is placed between the two heat-resistant metal plates 17 thus formed.
8 on both sides of the heat-resistant metal plate 17, a diameter of 5 mm,
A heat-resistant metal rod 19 made of a Ni-Cr alloy having a length of 460 mm is arranged parallel to the corrugation and welded to produce a separator 16 .

[0013] the cell 11 and the separator 16 fabricated as described above, as shown in FIG. 2, the longitudinal direction of the three cells 11 juxtaposed arranged parallel to the waveform of the separator 16, the cells 11 an oxidant electrode layer 15 made of the outermost layer of LaMnO ₃ is brought into contact with the coating layer made of LaMnO ₃ of the surface of the separator 16 are assembled. In the cylindrical solid oxide fuel cell of this embodiment, the unit cell 11 and the separator 1
6, the stack 21 by assembling as in FIG. 3
Is configured. That is, in this configuration, FIG.
The three unit cells 11 and the separators 16 are alternately stacked in three stages, and the separators 16 are arranged at both ends, and then the clamping plates 2 made of Ni-Cr alloy are provided at both ends.
Place 1, tightened by the nut 24 communicates the bolt 23 to the two clamping plates 22, the cell 11 and the separator 16
To form a stack 21 .

In this configuration, in the three unit cells 11 juxtaposed on the same separator 16 , the respective oxidant electrode layers 15 are electrically conductively connected to each other in parallel via the separator 16 . The heat-resistant metal cylinder 12
Since the exposed portions adjacent to the opening are conductively connected to each other in parallel via a metal wire (not shown), these three cells 11 are in a parallel connection state. On the other hand, between the unit cells 11 adjacent to each other in the stacking direction is electrically disconnected from each other by the non-conductive ceramic felt 18. Therefore, the refractory metal rods 19 welded to both ends of the separator 16 are connected to each other by metal wires, and by selecting a connection method at that time, the unit cells 11 in the stacking direction can be connected in parallel. It can also be connected in series.

FIG. 4 shows a stack 21 constructed as described above.
FIG. 6 is a partial cross-sectional view illustrating a configuration of a module 31 in which a module 32 is stored in a box 32. The inside of the box 32 includes a first partition 33 and a second partition 33.
By two partition walls of the partition wall 34, the fuel gas inlet manifold chamber 35, the fuel gas outlet manifold chamber 36, and is divided into three chambers of the battery chamber 37, the stack in the battery compartment 37 2
1 is stored.

The stack 21 is placed so that the longitudinal direction of the cylindrical unit cells 11 is vertical, and the upper end of the cylindrical opening of each unit cell 11 constituting the stack 21 passes through the first partition wall 33. And protrudes into the fuel gas outlet manifold chamber 36. A cell hanging ring 39 as shown in FIG. 5 is fitted to the cylindrical portion of the cell 11 protruding into the fuel gas outlet manifold chamber 36. By supporting, the unit cell 11 is suspended from the battery chamber 37 and held.

A thin tube 38 having one end disposed in the fuel gas inlet manifold chamber 35 and having openings at both ends penetrates through the second partition wall 34 and has a lower end located inside the upper opening of the cylindrical unit cell 11. It is inserted near. A thin tube hanging ring 45 is fitted to the thin tube 38 protruding into the fuel gas inlet manifold chamber 35, and the thin tube hanging ring 45
Is supported by the second partition wall 34, whereby the thin tube 38 is suspended and held inside the cylinder of the unit cell 11 . The fuel gas inlet manifold chamber 35 and the fuel gas outlet manifold chamber 36 are provided with a fuel gas supply pipe 41 and a fuel gas discharge pipe 42, respectively. The fuel gas supplied from the fuel gas supply pipe 40 is supplied to the fuel gas inlet manifold chamber 35.
Flows into the inside of the thin tube 38 and exits through the opening at the tip of the thin tube located near the lower end inside the cylinder of the unit cell 11 ,
After flowing upward inside the cylinder of 11, the cell
The fuel gas is introduced into the fuel gas outlet manifold chamber 36 from the opening end of the fuel cell 11 and discharged from the fuel gas discharge pipe 41 to the outside of the box 32.

In the battery chamber 37, a pair of oxidizing gas supply pipes 42 and oxidizing gas discharge pipes 43 are provided to face each other. The oxidizing gas is introduced from the oxidizing gas supply pipe 42 into the battery chamber 37, flows through the outer surfaces of the cylinders of the unit cells 11 disposed between the separators 16 of the stack 21 , and then oxidizes. Box 3 from the agent gas discharge pipe 43
2 to the outside.

The separator 16 was welded to the end.
One end of the heat-resistant metal rod 19 made of a Ni-Cr alloy penetrates the first partition wall 33 and protrudes into the fuel gas outlet manifold chamber 36, and a metal rod suspension ring 44 is fitted to the protruding portion. By supporting the metal rod suspension ring 44 by the first partition wall 33, the heat-resistant metal rod 19 and the separator 16 are suspended from the battery chamber 37 and held.

In this structure, the oxidizing gas should pass through the gap between the cylinder of the unit cell 11 and the first partition 33 or the gap between the heat-resistant metal rod 19 and the first partition 33 and from the battery chamber 37 to the upper part. Even if a situation occurs in which the fuel gas enters the fuel gas outlet manifold chamber 36, the invading oxidant gas reacts with the discharged fuel gas guided to the fuel gas outlet manifold chamber 36 to become steam, and together with the discharged fuel gas, the casing 32 , There is no danger of intrusion into the fuel gas inlet manifold chamber 35 filled with fuel gas.

Also, in the module 31 of this configuration, the unit cells projecting into the fuel gas outlet manifold chamber 36
Electrical connection is made by using the end of the heat-resistant metal cylinder 11 as a negative terminal and the end of the heat-resistant metal rod 19 protruding into the fuel gas outlet manifold chamber 36 as a positive terminal. Arbitrary current and voltage can be obtained by connecting these negative and positive terminals in series or in parallel with a connection line made of a heat-resistant metal material. In addition, since the fuel gas outlet manifold chamber 36 is kept in a reducing atmosphere, there is no possibility that these connection lines are oxidized and deteriorated.

As described above, the fuel electrode layer 13, the solid electrolyte layer 14, the oxidant electrode layer 1
The module 31 composed of the single cells 11 each having a cylindrical shape formed by heating 5 from room temperature to 1000 ° C., performing a power generation operation, and then reducing the temperature to room temperature again in 25 cycles.
A thermal cycling test that was repeated several times was performed. According to the results, no decrease in the battery performance was observed in each power generation operation stage, and no delamination of each layer of the single cell 11 was observed in the disassembly inspection after the test. That is, the cell 11
Fuel electrode layer 13, solid electrolyte layer 14, oxidant electrode layer 1
It was confirmed that, by forming the cylinder 5 in a cylindrical shape, the strength of each layer was improved, the occurrence of peeling was suppressed, and a decrease in battery performance was avoided.

<Embodiment 2> FIG. 6 is a structural view of a cylindrical unit cell of Embodiment 2 of the cylindrical solid oxide fuel cell of the present invention.
(A) is a perspective view, (b) is a longitudinal sectional view. The manufacturing method of the cylindrical unit cell 51 having this configuration is as follows. That is, it is manufactured by extrusion molding method using LaMnO ₃ , one end is similarly sealed with LaMnO ₃ , porosity 30%, outer diameter 20 mm, inner diameter 10
A porous cylinder 52 also serving as an oxidant electrode having a length of 460 mm and a length of 460 mm is formed. 20m from the open end of the formed porous cylinder 52
m and the entire outer peripheral surface except 80 mm from the bottom,
Thoroughly spray ZrO ₂ using the plasma spray method
A 100 μm solid electrolyte layer 54 is formed. Then, LaCrO ₃ is densely sprayed on the outer surface including the bottom from the bottom up to 80 mm by plasma spraying to form an interconnector layer 56 having a thickness of 100 μm. Next, 80 mm from the opening end
Roughly Ni-ZrO ₂ cermet (porosity 30%) on the entire surface of the 300 mm long part except the part and the part 80 mm from the bottom
A fuel cell layer 53 having a thickness of 100 μm is formed by flame spraying to produce a cylindrical unit cell 51 .

The unit cell 51 thus configured has a shape similar to that of the unit cell 11 of the first embodiment shown in FIG. 1, and the stack 2 of the first embodiment is used by using this unit cell 51.
1. It is obvious that a stack and a module having the same shape as the module 31 can be easily formed without being illustrated. The unit cell 51 differs from the unit cell 11 of the first embodiment in that the inner cylindrical porous cylinder 52 is used as an oxidant electrode and the outermost layer is used as a fuel electrode layer 53, so that the oxidant gas flows inside the cylinder. This causes the fuel gas to flow outside the cylinder. That is, the fuel gas flows through the battery chamber of the configured module, and the oxidizing gas flows through the upper part of the partition wall as an oxidizing gas inlet manifold chamber and an oxidizing gas outlet manifold chamber. Therefore, since the battery chamber is in a reducing atmosphere, it is not necessary to coat the heat-resistant metal plate constituting the separator with LaMnO ₃ coating for oxidation resistance.

The electrical connection between the unit cell 51 and the separator is made inside the battery chamber in a reducing atmosphere where there is no risk of metal oxidation. That is, the interconnector layer 56 formed near the bottom of the cylinder of the unit cell 51 is used as a positive terminal, and the heat-resistant metal rod welded to the end of the separator is used as a negative terminal. As a result, an arbitrary current and voltage can be obtained.

In the configuration of this embodiment, the unit cell51
However, the solid electrolyte layer 54 and the fuel
The electrode layer 53 and the interconnector layer 56 are formed in a cylindrical shape.
Because of the structure, the strength of each formed layer is high,
Detachment due to cycles is prevented, avoiding deterioration of battery performance
Will be done.

[0027]

As described above, according to the present invention, (1) a fuel made of, for example, Ni-ZrO ₂ cermet is provided on an outer peripheral surface of a conductive porous cylinder having one end sealed, for example, made of a heat-resistant metal material. electrode layer, for example, a solid electrolyte layer made of ZrO _2, for example, a unit cell of the oxidant electrode layer made of LaMnO ₃ is formed by stacking sequentially a cylindrical, for example a welded corrugated refractory metal rod into the end heat Between two conductive thin plates made of a metal plate, for example, a separator formed by sandwiching a non-conductive sheet made of heat-resistant glass fiber felt,
A plurality of unit cells and separators arranged side by side are alternately stacked and arranged to form a stack of a cylindrical solid oxide fuel cell, and a fuel gas containing hydrogen inside a conductive porous cylinder of the unit cells, In addition, since the oxidizing gas containing oxygen flows through the outer periphery of the unit cell, the electrolyte of the unit cell can be used even when a large heat cycle occurs or when overload causes sudden heat generation. It is possible to obtain a cylindrical solid oxide fuel cell that can be stably operated without the risk of separation of the layers and electrode layers.

(2) In addition, an electrically conductive porous material having one end sealed, for example, an oxidant electrode cylinder made of LaMnO _3, and an entire surface of the sealed bottom portion and an outer peripheral surface in the vicinity of the bottom are provided with a conductive connection material such as LaCrO 3 the interconnector layer of ₃ to form, and, on the outer peripheral surface of the oxidizing agent electrode cylinder adjacent to the interconnector layer, for example, a solid electrolyte layer made of ZrO _2, a fuel electrode layer made of, for example, Ni-ZrO ₂ cermet A non-conductive cell made of, for example, a heat-resistant glass fiber felt is placed between a unit cell formed by sequentially laminating a cylindrical shape and two conductive thin plates made of, for example, a corrugated heat-resistant metal plate with a heat-resistant metal rod welded to an end. A plurality of unit cells and separators arranged side by side with a conductive sheet interposed therebetween are alternately stacked and arranged to form a stack of a cylindrical solid oxide fuel cell. quality If the oxidizing gas is used inside the cylinder and the fuel gas is allowed to flow through the outer periphery of the unit cell, it can be used even when a large heat cycle occurs or when an overload causes sudden heat generation. It is suitable as a cylindrical solid oxide fuel cell that can be stably operated without the risk of peeling of the electrolyte layer or electrode layer of the unit cell.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a unit cell according to a first embodiment of the present invention, in which (a)
Is a perspective view, and (b) is a longitudinal sectional view.

FIGS. 2A and 2B are configuration diagrams of a combination of a unit cell and a separator according to Embodiment 1 of the present invention, wherein FIG. 2A is a cross-sectional view and FIG. 2B is a plan view seen from above FIG.

FIG. 3 is a cross-sectional view illustrating a configuration of a stack according to the first embodiment of the present invention.

FIG. 4 is a partial cross-sectional view illustrating a configuration of a module according to the first embodiment of the present invention.

FIG. 5 is a perspective view showing a hanging configuration of the unit cell according to the first embodiment of the present invention.

FIG. 6 is a configuration diagram of a unit cell according to a second embodiment of the present invention;
Is a perspective view, and (b) is a longitudinal sectional view.

FIG. 7 is a perspective view showing the structure of a unit cell of a conventional cylindrical solid oxide fuel cell.

FIG. 8 is a cross-sectional view of a stack of a conventional cylindrical solid oxide fuel cell.

DESCRIPTION OF SYMBOLS 11 unit cell 12 heat-resistant metal cylinder 13 fuel electrode layer 14 solid electrolyte layer 15 oxidant electrode layer 16 separator 17 heat-resistant metal plate 18 ceramic felt 19 heat-resistant metal rod 21 stack 22 clamping plate 23 bolt 24 nut 31 module 32 Box 33 First partition 34 Second partition 35 Fuel gas inlet manifold chamber 36 Fuel gas outlet manifold chamber 37 Battery chamber 38 Narrow tube 39 Single cell suspension ring 40 Fuel gas supply pipe 41 Fuel gas discharge pipe 42 Oxidant gas supply pipe 43 Oxidant gas discharge pipe 44 Metal rod hanging ring 45 Thin tube hanging ring 51 Single cell 52 Porous cylinder 53 Fuel electrode layer 54 Solid electrolyte layer 56 Interconnector layer

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI H01M 8/12 H01M 8/12

Claims (5)

[Claims] 1. A plurality of unit cells in which a fuel electrode layer, a solid electrolyte layer, and an oxidant electrode layer are sequentially stacked in a cylindrical shape on the outer peripheral surface of a conductive porous cylinder having one end sealed, When,
A fuel cell comprising a stack formed by alternately stacking a separator having a non-conductive sheet sandwiched between two conductive thin plates, and forming a fuel cell containing hydrogen inside a conductive porous cylinder of a unit cell A cylindrical solid oxide fuel cell, wherein a gas is used by flowing an oxidizing gas containing oxygen around the outer periphery of the unit cell. 2. The unit cell according to claim 1, wherein the conductive porous cylinder is made of a heat-resistant metal material, the fuel electrode layer is made of Ni-ZrO ₂ cermet, the solid electrolyte layer is made of ZrO ₂ , and the oxidant electrode layer is made of ZrO _2.
Cylindrical solid oxide fuel cell according to claim 1, characterized in that consists of LaMnO _3. 3. An interconnector layer for conductive connection is formed on an entire surface of a sealed bottom portion and an outer peripheral surface near the bottom portion of an oxidant electrode cylinder made of a conductive porous material having one end sealed, and an interconnector layer. A plurality of unit cells, each having a solid electrolyte layer and a fuel electrode layer sequentially laminated in a cylindrical shape on the outer peripheral surface of the oxidant electrode cylinder adjacent to the A stack formed by alternately stacking and arranging separators sandwiching a conductive sheet is provided, and an oxidizing gas is supplied inside the conductive porous cylinder of the cell, and a fuel gas is supplied to the outer peripheral portion of the cell. A cylindrical solid oxide fuel cell characterized by being used by flowing. 4. An electroconductive porous material forming an oxidant electrode cylinder of the unit cell is LaMnO ₃ , a solid electrolyte layer is made of ZrO ₂ , and a fuel electrode layer is made of Ni-ZrO ₂ cermet. 4. The cylindrical solid oxide fuel cell according to claim ₃ , wherein the interconnector layer is made of LaCrO3. 5. The separator according to claim 1, wherein the separator comprises a heat-resistant metal plate having a corrugated shape with a heat-resistant metal rod welded to an end thereof, and the non-conductive sheet comprises a heat-resistant glass fiber felt. 5. The cylindrical solid oxide fuel cell according to 2, 3, or 4.