JP5320946B2 - Single-chamber solid oxide fuel cell and single-chamber solid oxide fuel cell stack - Google Patents

Description

  The present invention relates to a single-chamber solid oxide fuel cell and a single-chamber solid oxide fuel cell stack.

  Conventionally, a flat plate type, a cylindrical type, and the like have been proposed as cell designs of solid oxide fuel cells (SOFC). A flat cell is one in which a fuel electrode and an air electrode are respectively arranged on the front and back surfaces of a plate-like electrolyte, and a plurality of cells formed in this way are used in a state where they are stacked via separators. The separator plays the role of separating the fuel gas and the oxidant gas supplied to each cell. Further, a gas seal is provided between each cell and the separator (for example, Patent Document 1).

On the other hand, a cylindrical cell has a fuel electrode and an air electrode arranged on the outer peripheral surface and inner peripheral surface of a cylindrical electrolyte, and a cylindrical vertical stripe type, a cylindrical horizontal stripe type, and the like have been proposed (for example, Patent Documents). 2).
JP-A-5-3045 (first page, FIG. 6) Japanese Patent Laid-Open No. 5-94830 (first page, FIG. 1)

  As described above, in the flat plate and cylindrical solid oxide fuel cells, a high output can be obtained by stacking a plurality of cells. Thus, conventionally known flat plate and cylindrical types are known. In the solid oxide fuel cell, a single cell and a separator are separate members, and not only the assembly process is required, but also a fuel gas supply pipe and an air supply pipe need to be provided. Therefore, there is a problem in that this leads to an increase in cost and an increase in size (cannot be made compact). In addition, since the single-chamber solid oxide fuel cell can generate power using a mixed gas of fuel gas and oxidant gas, the gas seal required for the flat plate type is not necessary, and the stack structure is simplified. However, since the power generation is performed in a situation where the fuel gas is diluted rather than the so-called two-chamber type in which the fuel gas and the oxidant gas are separated, there is a problem of low output, and the number of cell stages of the stack becomes even larger than the two-chamber type There was a problem.

  The present invention has been made to solve the above problems, and even in a single-chamber type, a single-chamber solid that suppresses the number of cell stages of the stack when stacked and is small in size and capable of increasing output. It is an object of the present invention to provide an oxide fuel cell and a single-chamber solid oxide fuel cell stack.

The single-chamber solid oxide fuel cell according to the present invention has been made to solve the above-described problem, and is partitioned by a plurality of porous partition walls extending in the coaxial direction to thereby have a plurality of through-holes extending in the coaxial direction. an insulating support hole is formed, a first electrode consisting of one of said plurality of porous fuel electrode and an air electrode disposed on the surface of the partition wall, disposed on a surface of the first electrode A porous electrolyte and a second electrode made of the other of the fuel electrode and the air electrode disposed on the surface of the electrolyte, and generates power with a mixed gas of fuel gas and oxidant gas.

  According to such a configuration, the plurality of through holes extending in the coaxial direction are formed by the plurality of porous partition walls, and the fuel electrode, the electrolyte, and the air electrode are stacked on the partition walls. Therefore, when a mixed gas of combustion gas and oxidant gas is supplied to each through hole, the mixed gas passes through the fuel electrode, the electrolyte, and the air electrode, and power generation is performed in the process. Moreover, since the mixed gas passes through the partition wall and is introduced into the adjacent through hole, it is used again for power generation. In this way, a plurality of through-holes are formed by the partition walls, and the fuel electrode, electrolyte, and air electrode are formed on the partition walls. By increasing the number of partition walls and through-holes, battery performance can be increased. It becomes. Further, the fuel cell can be reduced in size by reducing the through hole. Furthermore, since the single-chamber solid oxide fuel cell generates electric power in a mixed gas, it is not necessary to provide a fuel gas and an air gas supply pipe in each through hole, so that the size can be reduced. Further, since the size can be reduced, when a plurality of single-chamber solid oxide fuel cells are connected and stacked, the number of cell stages in the stack can be suppressed.

  The mixed gas supplied to the through hole first reacts with the second electrode (for example, the fuel electrode), then passes through the electrolyte, and reaches the first electrode (for example, the air electrode). Therefore, when the mixed gas flows into the first electrode (air electrode), the air gas becomes rich. Thereby, although it is a single chamber type solid oxide fuel cell, air gas can be efficiently sent to an air electrode, and an output can be improved. When the arrangement of the fuel electrode and the air electrode is opposite to the above, that is, when the first electrode is the fuel electrode and the second electrode is the air electrode, the mixed gas is firstly the air electrode. After reacting with, it passes through the electrolyte and reaches the fuel electrode. Therefore, when the mixed gas flows into the fuel electrode, the fuel gas becomes rich. In this case as well, the output can be improved.

  The single-chamber solid oxide fuel cell may further include a gas-impermeable blocking member that closes the through hole at one end of the support. According to such a configuration, the mixed gas flowing through the through hole collides with the closing member, and thereby diffuses in the radial direction of the through hole. This ensures that the mixed gas flows toward the partition wall. Therefore, since the mixed gas surely passes through the fuel electrode, the electrolyte, and the air electrode, power generation is reliably performed.

  The single-chamber solid oxide fuel cell may further include a combustion catalyst disposed on the outer periphery of the support. According to such a configuration, thermal energy is generated by contacting the combustion catalyst after the mixed gas has passed through the partition wall. As a result, the single-chamber solid oxide fuel cell can be kept at a high temperature, and the power generation efficiency can be increased.

The single-chamber solid oxide fuel cell stack according to the present invention is an insulating support in which a plurality of through-holes extending in the coaxial direction are formed by partitioning with a plurality of porous partition walls extending in the coaxial direction. A first electrode composed of one of a fuel electrode and an air electrode disposed on the surface of the plurality of porous partition walls, a porous electrolyte disposed on the surface of the first electrode, and the electrolyte A plurality of single-chamber solid oxide fuel cells including a fuel electrode and a second electrode made of the other of the air electrode disposed on the surface, and one of the first electrode and the second electrode is And the other of the two electrodes extends to the other axial end of the porous partition wall, and the plurality of single-chamber solid oxide fuel cells are extended to the axial end of the porous partition wall. So that one end and the other end face each other The single-chamber solid oxide fuel cell that is disposed along the axial direction of the through-hole and disposed at one end in the axial direction includes a closing member that closes the through-hole, and is adjacent to the And at least one interconnector disposed between the single-chamber solid oxide fuel cells and electrically connecting the first electrode and the second electrode.

  The single-chamber solid oxide fuel cell stack may further include a gas-impermeable blocking member that closes the through hole at one end of the support. Moreover, the combustion catalyst arrange | positioned at the outer periphery of a support body can be further provided. Further, the interconnector can be formed in a mesh shape.

  According to such a configuration, the same effects as those of the single-chamber solid oxide fuel cell described above can be obtained. Further, since a plurality of solid oxide fuel cells are connected, high output can be obtained.

  Further, in the single-chamber solid oxide fuel cell stack, the plurality of single-chamber solid oxide fuel cells each include a plurality of the through holes in a cross section perpendicular to the axial direction of the through holes. The total cross-sectional area may be different. Furthermore, the plurality of single-chamber solid oxide fuel cells may be arranged so that the total cross-sectional area of the through-holes increases in order from one side of the axial direction to the other side. The cross-sectional area of the through hole refers to the cross-sectional area of the cavity formed by stacking the first electrode, the electrolyte, and the second electrode on the partition wall. The total cross-sectional area is the sum of the cross-sectional areas of a plurality of through holes in one single-chamber solid oxide fuel cell.

  In such a configuration, in the plurality of single-chamber solid oxide fuel cells, the total cross-sectional areas of the plurality of through holes are different from each other, so that the areas of the electrodes in contact with the mixed gas are different. Thereby, the output in each single-chamber solid oxide fuel cell is different. That is, in the single-chamber solid oxide fuel cell in which the total cross-sectional area of the through holes is relatively small, the output can be relatively suppressed because the electrode area is relatively small. On the other hand, in the single-chamber solid oxide fuel cell in which the total cross-sectional area of the through holes is relatively large, the output can be relatively increased because the electrode area is relatively large. Therefore, according to such a configuration, by supplying the mixed gas from the single-chamber solid oxide fuel cell on one side in the axial direction, the output of the mixed gas in a high concentration state is relatively low It can be supplied to a single-chamber solid oxide fuel cell. And after the density | concentration of mixed gas becomes low, this mixed gas can be supplied to a single chamber type solid oxide fuel cell with a relatively high output. As a result, the output of the single-chamber solid oxide fuel cell can be adjusted according to the concentration of the mixed gas, so that the entire single-chamber solid oxide fuel cell stack can generate power in a well-balanced manner. Therefore, the temperature of the entire single chamber type solid oxide fuel cell stack can be made uniform, so that the single chamber type solid oxide fuel cell can be prevented from being destroyed.

  In the single-chamber solid oxide fuel cell stack, the interconnector can have various structures. For example, if the interconnector is formed in a mesh shape, the mixed gas permeates, so the single-chamber solid oxide fuel cell. It can arrange | position to the whole surface of both the end surfaces. Therefore, the current collection efficiency is increased and a high output can be obtained.

  According to the present invention, even in a single chamber type, the number of cell stages in the stack can be suppressed, and high output can be achieved while being small.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, a single single-chamber solid oxide fuel cell, that is, a single cell will be described. FIG. 1 is a perspective view of a single-chamber solid oxide fuel cell (hereinafter simply referred to as a fuel cell) according to an embodiment of the present invention. 1A is a perspective view of a state in which one side of the fuel cell faces forward, and FIG. 1B is a perspective view of a state in which the other side of the fuel cell faces forward. 2A is a cross-sectional view taken along line XX in FIG. 1, and FIG. 2B is a cross-sectional view taken along line YY in FIG.

  As shown in FIGS. 1 and 2, the fuel cell 1 includes an insulating support 2. The support body 2 includes a plurality of partition walls 20 extending in the coaxial direction. The plurality of partition walls 20 are made of a porous material and are arranged in a lattice shape. Further, the support 2 includes a plurality of through holes 3 formed by partitioning with a plurality of partition walls 20, and the through holes 3 extend in the same direction as the partition walls 20. In the present embodiment, the support 2 has four rectangular through holes 3 arranged in a lattice pattern.

  A fuel electrode 4 (first electrode) is disposed on the surface of each partition wall 20. As shown in FIG. 2, the fuel electrode 4 covers the side surface of the partition wall 20, and extends from this side surface to one end portion (the lower end surface in FIG. 2A) of the partition wall 20. Thereby, the one end surface of the support body 2 is covered with the fuel electrode 4, and the fuel electrode 4 is exposed.

  An electrolyte 5 made of a porous material is disposed on the surface of the fuel electrode 4. As shown in FIG. 2, the electrolyte 5 covers the fuel electrode 4 on the side surface side of the partition wall 20, and extends from there to the other end of the partition wall 20 (upper end surface in FIG. 2A). Further, the electrolyte 5 covers the side surface and the end of the fuel electrode 4 so that the fuel electrode 4 and the air electrode 6 do not come into contact with each other.

  An air electrode 6 (second electrode) is disposed on the surface of the electrolyte 5. As shown in FIG. 2, the air electrode 6 covers the electrolyte 5 on the side surface side of the partition wall 20, and extends from there to the other end of the partition wall 20 (upper end surface in FIG. 2A). Thereby, the other end part of the support body 2 is covered with the air electrode 6, and the air electrode 6 is exposed.

  All of the partition wall 20, the fuel electrode 4, the electrolyte 5, and the air electrode 6 described above have gas permeability.

  Next, a configuration including a plurality of fuel cells, that is, a single-chamber solid oxide fuel cell stack will be described. FIG. 3 is a perspective view of a single-chamber solid oxide fuel cell stack (hereinafter simply referred to as a fuel cell stack) according to an embodiment of the present invention. In FIG. 3, each member is shown in a separated state in order to easily show each configuration of the fuel cell stack. 4 is a cross-sectional view taken along the line XX of FIG. FIG. 4 shows a state in which each member of the fuel cell stack is coupled.

  As shown in FIGS. 3 and 4, the fuel cell stack 10 is configured by connecting a plurality of fuel cells 1 (single cells). The plurality of fuel cells 1 are arranged side by side along the axial direction of the through hole 3 and are arranged so that the through holes 3 of the adjacent fuel cells 1 communicate with each other. Adjacent fuel cells 1 are arranged such that the fuel electrode 4 exposed at one end of one fuel cell 1 and the air electrode 6 exposed at the other end of the other fuel cell 1 face each other. ing. In the embodiment shown in FIG. 4, the fuel electrode 4 exposed at the end of the fuel cell 1 is arranged to face the right direction, and the exposed air electrode 6 is arranged to face the left direction.

  An interconnector 7 is disposed between adjacent fuel cells 1, and the adjacent fuel cells 1 are electrically connected to each other by the interconnector 7. More specifically, the interconnector 7 is in contact with the fuel electrode 4 of one fuel cell 1 and the air electrode 6 of the other fuel cell 1 in the adjacent fuel cell 1. The plurality of fuel cells 1 are connected in series. The interconnector 7 is formed in a mesh shape and is configured to allow gas to pass therethrough.

  Among the plurality of fuel cells 1, the fuel cell 1 disposed at one end in the axial direction includes a closing member 11 that closes the through hole 3 at one end of the support 2. In the present embodiment, the fuel cell 1 arranged at the right end in FIG. The closing member 11 is fixed to the fuel cell 1 so as to cover one end of the through hole 3. The closing member 11 can be fixed using a sealing material (not shown).

  Subsequently, materials constituting the fuel cell will be described.

  The material of the support 2 is not particularly limited as long as it is an insulating material. For example, a ceramic material such as an alumina material, a silica material, and a zirconia material can be preferably used. Moreover, it is preferable that the support body 2 has heat resistance. Moreover, the support body 2 can also be formed by coat | covering a metal with the above ceramic materials from a viewpoint of improving mechanical strength. In this case, for example, SUS can be used as the metal. Further, the ceramic material can be coated using, for example, a thermal spraying method or the like.

  As the material of the electrolyte 5, those known as electrolytes for single-chamber solid oxide fuel cells can be used. For example, ceria oxide doped with samarium or gadolinium, lanthanum doped with strontium or magnesium, etc. -Oxygen ion conductive ceramic materials such as galide oxides, zirconia oxides containing scandium and yttrium can be used. The electrolyte 5 is made of a porous material.

  The fuel electrode 4 and the air electrode 6 can be formed of a ceramic powder material. The average particle size of the powder used at this time is preferably 10 nm to 100 μm, more preferably 50 nm to 50 μm, and particularly preferably 100 nm to 10 μm. In addition, an average particle diameter can be measured according to JISZ8901, for example.

  The fuel electrode 4 can use, for example, a mixture of a metal catalyst and a ceramic powder material made of an oxide ion conductor. As the metal catalyst used at this time, a material that is stable in a reducing atmosphere, such as nickel, iron, cobalt, or a noble metal (platinum, ruthenium, palladium, etc.) and has hydrogen oxidation activity can be used. In addition, as the oxide ion conductor, one having a fluorite structure or a perovskite structure can be preferably used. Examples of those having a fluorite structure include ceria-based oxides doped with samarium, gadolinium, and the like, and zirconia-based oxides containing scandium and yttrium. In addition, examples of those having a perovskite structure include lanthanum galide oxides doped with strontium and magnesium. Among the above materials, it is preferable to form the fuel electrode with a mixture of an oxide ion conductor and nickel. The mixed form of the ceramic material made of the oxide ion conductor and nickel may be a physical mixed form, or may be a powder modification to nickel or a nickel modification to ceramic material. Good. Moreover, the ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types. The fuel electrode 4 can also be configured using a metal catalyst alone.

As the ceramic powder material forming the air electrode 6, for example, a metal oxide made of Co, Fe, Ni, Cr, Mn, or the like having a perovskite structure or the like can be used. Specifically, (Sm, Sr) CoO ₃ , (La, Sr) MnO ₃ , (La, Sr) CoO ₃ , (La, Sr) (Fe, Co) O ₃ , (La, Sr) (Fe, Co , Ni) O _{3 and the} like, and (La, Sr) (Fe, Co) O ₃ is preferable. The ceramic material mentioned above can be used individually by 1 type or in mixture of 2 or more types.

  The fuel electrode 4, the electrolyte 5, and the air electrode 6 can be formed by, for example, a wet coating method. Examples of the wet coating method include a spray method, a dispenser coating method, and a dip coating method. At that time, the fuel electrode 4, the electrolyte 5, and the air electrode 6 need to be paste-like, and are formed by adding appropriate amounts of a binder resin, an organic solvent, and the like with the above-described material as a main component. More specifically, it is preferable to add a binder resin or the like so that the main component is 50 to 95% by weight in the mixing of the main component and the binder resin.

The interconnector 7 is made of, for example, a conductive metal material such as Pt, Au, Ag, Ni, Cu, and a stainless steel material, or La (Cr, Mg) O ₃ , (La, Ca) CrO ₃ , (La, Sr). It can be formed of a lanthanum / chromite-based conductive metal oxide material such as CrO _3, and one of these may be used alone, or a mixture of two or more may be used. Good.

  The material of the closing member 11 is not particularly limited as long as it has gas impermeability. For example, a metal material such as SUS, a ceramic material such as an alumina material, a silica material, and a zirconia material. Can be preferably used. Moreover, it is preferable that the closure member 11 has heat resistance.

  The material of the sealing material for fixing the closing member 11 to the fuel cell 1 is not particularly limited as long as it has gas impermeability. For example, Pyrex glass ("Pyrex" is a registered trademark), soda glass, and the like Glass materials and ceramic bonds can be used.

  Next, an example of a method for manufacturing the fuel cell configured as described above will be described. First, the manufacturing method of the support body 2 is demonstrated. First, the powder material of the support 2 described above and a binder are kneaded, and extrusion molding is performed so that a plurality of rectangular through holes 3 are formed. Then, the support body 2 is created by sintering the extruded product at a predetermined temperature.

  Subsequently, a fuel electrode paste, an electrolyte paste, and an air electrode paste are prepared. And after masking the outer peripheral surface of the support body 2 and the surface which forms the air electrode 6, the support body 2 is immersed in the container which accommodated the fuel electrode paste from one end part, and a fuel electrode paste is surfaced on the surface of the support body 2 Apply to. Thereafter, the fuel electrode 4 is formed by drying and sintering at a predetermined temperature for a predetermined time.

  Next, the support body 2 on which the fuel electrode 4 is formed is immersed from the other end in a container containing the electrolyte paste, and the electrolyte paste is applied to the surface of the fuel electrode 4. At this time, it is preferable to mask the portion where the electrolyte paste is not applied. Thereafter, the electrolyte 5 is formed by drying and sintering at a predetermined temperature for a predetermined time.

  Next, the support body 2 on which the electrolyte 5 is formed is immersed from the other end in a container in which the air electrode paste is accommodated, and the air electrode paste is applied to the surface of the electrolyte 5. At this time, it is preferable to mask the portion where the air electrode paste is not applied. Thereafter, the air electrode 6 is formed by drying and sintering at a predetermined temperature for a predetermined time. Thus, the fuel cell is completed.

  In the fuel cell and the fuel cell stack configured as described above, power generation is performed as follows. First, as shown in FIGS. 3 and 4, the mixed gas G is supplied from one end side (left side in FIG. 4) of the fuel cell stack 10 to the through hole 3 of the leftmost fuel cell 1. The mixed gas G is a mixture of hydrogen or a fuel gas composed of a hydrocarbon such as methane or ethane and an oxidant gas such as air. Part of the supplied mixed gas G diffuses in the radial direction of the through hole 3 and passes through the air electrode 6, the electrolyte 5, the fuel electrode 4, and the partition wall 20 as indicated by arrows in FIG. 4. . A part of the mixed gas G is introduced into the adjacent through hole 3, and the other part flows out of the fuel cell 1. In this process, the mixed gas G is consumed at the air electrode 6 and the fuel electrode 4, and oxygen ion conduction through the electrolyte 1 occurs between the air electrode 6 and the fuel electrode 4, thereby generating power. Since the mixed gas G is supplied to the fuel electrode 4 after the oxidizing gas is consumed at the air electrode 6, the ratio of the fuel gas is high in the fuel electrode 4. Therefore, the output can be increased.

  A part of the mixed gas G in the through hole 3 goes straight in the axial direction of the through hole 3, passes through the mesh-like interconnector 7, and is introduced into the through hole 3 adjacent in the axial direction. . As described above, a part of the mixed gas G in the through hole 3 diffuses in the radial direction of the through hole 3, and as indicated by arrows in FIG. 4, the air electrode 6, the electrolyte 5, the fuel electrode 4, And it passes through the partition wall 20. As a result, power is also generated in the adjacent fuel cell 1. Further, the mixed gas G flowing in the axial direction of the through-hole 3 finally diffuses in the radial direction of the through-hole 3 by colliding with the closing member 11.

  According to the fuel cell 1 and the fuel cell stack 10 according to the present embodiment, as described above, the plurality of through holes 3 are formed by the partition wall 20, and the fuel electrode 4, the electrolyte 5, and the air electrode 6 are formed in the partition wall 20. Since it is formed, the output can be improved by increasing the number of the partition walls 20 and the through holes 3. Further, by making the through hole 3 small, the fuel cell 1 and the fuel cell stack 10 can be reduced in size.

  Further, by providing the closing member 11, the mixed gas G collides with the closing member 11 and diffuses in the radial direction of the through hole 3, so that the mixed gas G can flow reliably toward the partition wall 20. Thereby, power generation can be performed reliably.

  As mentioned above, although one Embodiment of this invention was described, the specific aspect of this invention is not limited to the said embodiment.

  For example, in the present embodiment, the first electrode arranged on the surface of the partition wall 20 is constituted by the fuel electrode 4, and the second electrode arranged on the surface of the electrolyte 5 is constituted by the air electrode 6. However, it is not limited to this configuration, and the positions of the fuel electrode 4 and the air electrode 6 may be exchanged. That is, the air electrode 6 (first electrode) may be disposed on the surface of the partition wall 20, and the fuel electrode 4 (second electrode) may be disposed on the surface of the electrolyte 5.

  Moreover, in this embodiment, although the external shape of the support body 2 was a rectangular parallelepiped, a shape can be changed suitably and a cylindrical shape, a pentagonal shape, a hexagonal cylindrical shape, etc. may be sufficient. Furthermore, although the through-hole 3 is also rectangular, for example, the cross-sectional shape of each opening may be an isosceles triangle, a regular triangle, a regular pentagon, a regular hexagon, or the like. In addition, a design in which openings having different shapes such as a regular triangle and a regular hexagon are adjacent to each other is possible. Further, the number of through holes 3 is not particularly limited.

  The cross-sectional area of the through hole 3 can be changed as appropriate. FIG. 5 is a cross-sectional view of a fuel cell stack according to another embodiment of the present invention. 5, the same components as those in FIG. 4 are denoted by the same reference numerals and description thereof is omitted. 6 is (a) an XX sectional view in FIG. 5, (b) a YY sectional view in FIG. 5, and (c) a ZZ sectional view in FIG. 5 and 6, the fuel cell disposed on one end side in the axial direction (left side in FIGS. 5 and 6) among the plurality of fuel cells disposed along the axial direction of the through hole 3 is the first fuel. The fuel cell disposed on the other end side (the right side in FIGS. 5 and 6) is referred to as a third fuel cell c3, and the fuel cell disposed between them is referred to as a second fuel cell c2.

  As shown in FIGS. 5 and 6, the first fuel cell c <b> 1, the second fuel cell c <b> 2, and the third fuel cell c <b> 3 have different cross-sectional areas of the through holes 3. In the present specification, the cross-sectional area of the through hole 3 refers to a cross-sectional area of a hollow portion formed by laminating the fuel electrode 4, the electrolyte 5, and the air electrode 6 on the partition wall 20. That is, it refers to the cross-sectional area of the cavity portion formed inside the inner surface of the second electrode (in this embodiment, the air electrode 6).

  As shown in FIG. 6, in the first fuel cell c1, in the cross section perpendicular to the axial direction of the through hole 3 (the XX cross section in FIG. 5), one through hole 3 has a cross-sectional area m1. . Further, since the first fuel cell c1 includes the four through holes 3, the total cross-sectional area M1 of the plurality of through holes 3 in a cross section perpendicular to the axial direction of the through hole 3 is (one through hole 3). Of the cross section: m1) × (number of through holes 3: 4).

  Similarly, in the second fuel cell c2, in the cross section perpendicular to the axial direction of the through hole 3 (YY cross section in FIG. 5), one through hole 3 has a cross-sectional area m2. Further, the total cross-sectional area M2 of the plurality of through-holes 3 in a cross section perpendicular to the axial direction of the through-hole 3 is (cross-sectional area of one through-hole 3: m2) × (number of through-holes 3: 4). Further, similarly, in the third fuel cell c3, in the cross section perpendicular to the axial direction of the through hole 3 (the ZZ cross section in FIG. 5), one through hole 3 has a cross-sectional area m3. Further, the total cross-sectional area M3 of the plurality of through-holes 3 in a cross section perpendicular to the axial direction of the through-hole 3 is (cross-sectional area of one through-hole 3: m3) × (number of through-holes 3: 4).

  The total cross-sectional areas M1, M2, and M3 of the through holes 3 in the first fuel cell c1, the second fuel cell c2, and the third fuel cell c3 are increased in this order. That is, M1 <M2 <M3.

  The first fuel cell c1, the second fuel cell c2, and the third fuel cell c3 are arranged in order from one side of the through hole 3 in the axial direction to the other side. That is, the plurality of fuel cells are arranged so that the total cross-sectional area of the through-holes 3 increases in order from one side in the axial direction to the other side. The mixed gas G is supplied from the first fuel cell c1.

  According to such a configuration, the total cross-sectional area of the through hole 3 increases in the order of the first fuel cell c1, the second fuel cell c2, and the third fuel cell c3. The area also increases in order. Thereby, in the 1st fuel cell c1, the area of the electrode which the mixed gas G contacts can be made relatively small with respect to the 2nd fuel cell c2 and the 3rd fuel cell c3. Moreover, in the 2nd fuel cell c2 and the 3rd fuel cell c3, the area of the electrode which the mixed gas G contacts with respect to the 1st fuel cell c1 can be enlarged relatively in order. Therefore, power generation can be performed with a relatively small electrode area on the upstream side of the mixed gas G, and power generation can be performed with a relatively large electrode area on the downstream side. Thereby, on the upstream side where the concentration of the mixed gas G is high, the output can be suppressed relative to the downstream side. On the other hand, on the downstream side where the concentration is low, the output can be increased relative to the upstream side. As described above, since the relative output can be adjusted according to the concentration of the mixed gas G, the fuel cell stack 10 as a whole can generate power in a well-balanced manner. Therefore, the temperature of the entire fuel cell stack 10 can be made uniform, so that the fuel cell 1 can be prevented from being destroyed.

  FIG. 7 is a cross-sectional view of a fuel cell stack according to still another embodiment of the present invention. As shown in FIG. 7, the fuel cell 1 may include a combustion catalyst 12 disposed on the outer periphery of the support 2. The combustion catalyst 12 is applied to the outer peripheral surface of the support 2. The material of the combustion catalyst 12 is preferably one that can generate thermal energy by reacting the mixed gas G with oxygen in the air on the catalyst surface, and specifically, a metal catalyst such as Ni, Ru, Pt, Rh is preferable. . These metal catalysts can be used in a state of being supported by a carrier such as alumina. The combustion catalyst 12 can be formed by, for example, a spray coating method. That is, first, masking is performed on a portion of the fuel cell 1 where the combustion catalyst 12 is not formed. Subsequently, a combustion catalyst paste is prepared, and the combustion catalyst paste is applied to the fuel cell 1 by spraying. The combustion catalyst paste can be manufactured by mixing a binder and a solvent with a powder such as Pt which is a material of the combustion catalyst 12. Thereafter, the combustion catalyst 12 is formed by drying and sintering at a predetermined temperature for a predetermined time.

  According to such a configuration, the mixed gas G passes through the partition wall 20 and then contacts the combustion catalyst 12 to generate thermal energy. Thereby, the fuel cell 1 can be kept at a high temperature, and the power generation efficiency can be increased.

1 is a perspective view of a single chamber type solid oxide fuel cell according to an embodiment of the present invention. (A) XX sectional drawing in FIG. 1, (b) YY sectional drawing in FIG. 1 is a perspective view of a fuel cell stack according to an embodiment of the present invention. It is sectional drawing of the fuel cell stack which concerns on one Embodiment of this invention. It is sectional drawing of the fuel cell stack which concerns on other embodiment of this invention. (A) XX sectional view in FIG. 5, (b) YY sectional view in FIG. 5, (c) ZZ sectional view in FIG. FIG. 6 is a perspective view of a fuel cell stack according to still another embodiment of the present invention.

Explanation of symbols

G Mixed Gas 1 Single-chamber Solid Oxide Fuel Cell 2 Support 3 Through Hole 4 Fuel Electrode 5 Electrolyte 6 Air Electrode 7 Interconnector 11 Blocking Member 12 Combustion Catalyst 20 Bulkhead

Claims (6)

An insulating support in which a plurality of through-holes extending in the coaxial direction are formed by being partitioned by a plurality of porous partition walls extending in the coaxial direction; and
A first electrode formed of one of said plurality of porous fuel electrode and an air electrode disposed on the surface of the partition wall,
A porous electrolyte disposed on the surface of the first electrode;
A single-chamber solid oxide fuel cell, comprising a second electrode made of the other of the fuel electrode and the air electrode disposed on the surface of the electrolyte, and generating electric power with a mixed gas of fuel gas and oxidant gas.   The single-chamber solid oxide fuel cell according to claim 1, further comprising a gas-impermeable blocking member that blocks the through hole at one end of the support.   The single-chamber solid oxide fuel cell according to claim 1 or 2, further comprising a combustion catalyst disposed on an outer periphery of the support. By partitioning with a plurality of porous partition walls extending in the coaxial direction, an insulating support having a plurality of through-holes extending in the coaxial direction, a fuel electrode disposed on the surfaces of the plurality of porous partition walls, and A first electrode composed of one of the air electrodes , a porous electrolyte disposed on the surface of the first electrode, and a second electrode composed of the other of the fuel electrode and the air electrode disposed on the surface of the electrolyte A plurality of single-chamber solid oxide fuel cells comprising
Either one of the first electrode and the second electrode extends to one axial end of the porous partition, and the other of the two electrodes extends to the other axial end of the porous partition. Extended,
The plurality of single-chamber solid oxide fuel cells are arranged along the axial direction of the through hole such that one end and the other end face each other.
A single-chamber solid oxide, further comprising at least one interconnector that is disposed between adjacent single-chamber solid oxide fuel cells adjacent to each other and electrically connects the first electrode and the second electrode; Physical fuel cell stack.   Each of the plurality of single-chamber solid oxide fuel cells has a cross-sectional area perpendicular to the axial direction of the through-holes, the total cross-sectional areas of the plurality of through-holes being different, and one side in the axial direction. 5. The single-chamber solid oxide fuel cell stack according to claim 4, wherein the through-holes are arranged so that a total cross-sectional area gradually increases from the first side toward the other side.   The single-chamber solid oxide fuel cell stack according to claim 4 or 5, wherein the interconnector is formed in a mesh shape.

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