JP6586504B1 - Cell stack device - Google Patents

Abstract

[PROBLEMS] To suppress the occurrence of cracks in a bonding material. A cell stack device includes a manifold, a plate-shaped fuel cell, and a bonding material. The manifold 2 has a top plate 231 including a through hole. The fuel cell 10 has a base end face 103 that faces the top plate 231 so as to cover the through hole. The bonding material 104 is filled in a gap between the top plate 231 and the base end surface 103 of the fuel cell 10. The bonding material 104 has a center region A1 located at the center in the width direction of the fuel cell 10 and an end region A2 located at the end in the width direction. The pore diameter in the central region A1 is larger than the pore diameter in the end region A2. [Selection] Figure 9

Description

  The present invention relates to a cell stack device.

  The cell stack device has a fuel cell and a manifold. The fuel cell extends upward from the top plate of the manifold. Further, the fuel cell is fixed to the top plate of the manifold by a bonding material.

Japanese Unexamined Patent Publication No. 2016-225035

  In the above-described cell stack device, since the central portion in the width direction of the fuel cell becomes high temperature, there is a problem that stress is likely to be generated in the central region of the bonding material and cracks may occur.

  The subject of this invention is suppressing generation | occurrence | production of the crack in a joining material.

  The cell stack device according to the first aspect of the present invention includes a manifold, a plate-like fuel cell, and a bonding material. The manifold has a top plate including a through hole. The fuel cell has a base end surface facing the top plate of the manifold so as to cover the through hole. The fuel cell extends from the manifold. The bonding material is filled in a gap between the top plate of the manifold and the base end surface of the fuel cell. The joining material joins the manifold and the fuel battery cell. The bonding material has a central region located at the central portion in the width direction of the fuel cell and an end region located at the end portion in the width direction. The pore diameter in the central region is larger than the pore diameter in the end region.

  According to this configuration, since the pore diameter in the central region is larger than the pore diameter in the end region, the central region of the bonding material is more easily deformed than the end region. For this reason, the stress which arises in the center area | region of a joining material can be relieved, and generation | occurrence | production of the crack in a joining material can be suppressed.

  Preferably, the distance between the base end surface of the fuel cell in the center portion in the width direction and the top plate is larger than the distance between the base end surface of the fuel cell in the end portion in the width direction and the top plate.

  Preferably, the distance between the base end face of the fuel cell and the top plate of the manifold gradually increases from both ends in the width direction toward the center.

  Preferably, the base end surface of the fuel cell is curved so that the center portion in the width direction is farther from the top plate than both end portions in the width direction.

  Preferably, the top plate is curved so that the center portion in the width direction is farther from the base end face of the fuel cell than both end portions in the width direction.

  Preferably, the base end surface of the fuel battery cell contacts the top plate at both ends in the width direction.

  Preferably, the porosity in the central region is greater than the porosity in the end region.

  The cell stack device according to the second aspect of the present invention includes a manifold, a plate-like fuel cell, and a bonding material. The manifold has a top plate including a through hole. The fuel cell has a base end surface facing the top plate of the manifold so as to cover the through hole. The fuel cell extends from the manifold. The bonding material is filled in a gap between the top plate of the manifold and the base end surface of the fuel cell. The joining material joins the manifold and the fuel battery cell. The bonding material has a central region located at the central portion in the width direction of the fuel cell and an end region located at the end portion in the width direction. The porosity in the central region is greater than the porosity in the end region.

  According to this configuration, since the porosity in the central region is larger than the porosity in the end region, the central region of the bonding material is more easily deformed than the end region. For this reason, the stress which arises in the center area | region of a joining material can be relieved, and generation | occurrence | production of the crack in a joining material can be suppressed.

  According to the present invention, the occurrence of cracks in the bonding material can be suppressed.

The perspective view of a cell stack apparatus. Sectional drawing of a manifold. The top view of a manifold. Sectional drawing of a cell stack apparatus. The perspective view of a fuel cell. Sectional drawing of a fuel cell. The enlarged plan view of a manifold. The enlarged front view of a cell stack apparatus. The expanded sectional view of a cell stack device. XX sectional drawing of FIG. The figure equivalent to FIG. 9 of the cell stack apparatus which concerns on a modification. The figure equivalent to FIG. 9 of the cell stack apparatus which concerns on a modification. The figure equivalent to FIG. 9 of the cell stack apparatus which concerns on a modification. The figure equivalent to FIG. 10 of the cell stack apparatus which concerns on a modification. Sectional drawing of the cell stack apparatus which concerns on a modification. The figure equivalent to FIG. 3 of the manifold which concerns on a modification.

  Hereinafter, an embodiment of a cell stack device according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a cell stack apparatus. In addition, in FIG. 1, description of some fuel cells is abbreviate | omitted.

[Cell stack equipment]
As shown in FIG. 1, the cell stack device 100 includes a manifold 2, a plurality of fuel cells 10, and a bonding material 104.

[Manifold]
The manifold 2 is configured to supply gas to the plurality of fuel cells 10. The manifold 2 is configured to collect gas discharged from the fuel battery cell 10.

  FIG. 2 is a cross-sectional view of the manifold. In FIG. 2, only a part of the through holes are indicated by imaginary lines. As shown in FIG. 2, the manifold 2 has a gas supply chamber 21 and a gas recovery chamber 22. Fuel gas is supplied to the gas supply chamber 21 from a fuel gas supply source via a reformer or the like. The gas recovery chamber 22 recovers the offgas of the fuel gas used in each fuel cell 10.

  The manifold 2 has a manifold main body 23 and a partition plate 24. The manifold body 23 has a space inside. The manifold main body 23 has a rectangular parallelepiped shape.

  The partition plate 24 partitions the space of the manifold body 23 into a gas supply chamber 21 and a gas recovery chamber 22. Specifically, the partition plate 24 extends in the length direction of the manifold body 23 at a substantially central portion of the manifold body 23. In the present embodiment, the partition plate 24 completely partitions the space of the manifold body 23, but a gap may be formed between the partition plate 24 and the manifold body 23.

  A gas supply port 211 is formed on the bottom surface of the gas supply chamber 21. A gas discharge port 221 is formed on the bottom surface of the gas recovery chamber 22. The gas supply port 211 may be formed on the side surface or the upper surface of the gas supply chamber 21, and the gas discharge port 221 may be formed on the side surface or the upper surface of the gas recovery chamber 22.

  For example, the gas supply port 211 is disposed closer to the first end 201 than the center C of the manifold 2 in the arrangement direction (z-axis direction) described later. On the other hand, the gas discharge port 221 is disposed, for example, on the second end 202 side with respect to the center C of the manifold 2 in the arrangement direction (z-axis direction).

  As shown in FIGS. 2 to 4, the manifold 2 includes a top plate 231, a bottom plate 232, and a side plate 233. The top plate 231, the bottom plate 232, and the side plate 233 constitute the manifold body 23. The bottom plate 232 and the side plate 233 are composed of one member. The top plate 231 is joined to the upper end portion of the side plate 233. The top plate 231 and the side plate 233 may be formed of a single member, and the bottom plate 232 may be joined to the lower end portion of the side plate 233.

  As shown in FIG. 3, the top plate 231 of the manifold 2 has a plurality of through holes 234 and a plurality of crosspieces 235. In addition, the top plate 231 has a plurality of connection reinforcing portions 236. Each through hole 234 communicates the inside and the outside of the manifold 2. Each through hole 234 opens into the gas supply chamber 21 and the gas recovery chamber 22.

  The connection reinforcing portion 236 crosses the through holes 234 in the arrangement direction and connects the pair of crosspieces 235 to each other. That is, the connection reinforcing portion 236 extends from one of the pair of adjacent crosspieces 235 to the other crosspiece 235 across the through hole 234.

  The through hole 234 is divided into a plurality of divided holes by a connection reinforcing portion 236 that crosses the through hole 234. In the present embodiment, each through hole 234 is divided into a first divided hole 234a and a second divided hole 234b.

  As shown in FIG. 2, the first divided hole 234 a communicates with the gas supply chamber 21. The second divided hole 234 b communicates with the gas recovery chamber 22. The connection reinforcing portion 236 is disposed at the boundary between the gas supply chamber 21 and the gas recovery chamber 22. That is, the connection reinforcing portion 236 overlaps with the boundary portion between the gas supply chamber 21 and the gas recovery chamber 22 in plan view (viewed in the x-axis direction). In the present embodiment, the connection reinforcing portion 236 overlaps with the partition plate 24 in plan view (viewed in the x-axis direction).

[Fuel battery cell]
FIG. 4 shows a cross-sectional view of the cell stack device. As shown in FIG. 4, the fuel cell 10 extends upward from the top plate 231 of the manifold 2. The fuel cell 10 is plate-shaped and has a base end portion 101 and a tip end portion 102. The fuel cell 10 has a base end 101 attached to the manifold 2. That is, the manifold 2 supports the base end portion 101 of each fuel cell 10. In the present embodiment, the base end portion 101 of the fuel cell 10 means the lower end portion, and the tip end portion 102 of the fuel cell 10 means the upper end portion.

  As shown in FIGS. 4 and 5, the fuel cell 10 includes a support substrate 4, a plurality of first gas passages 41, a plurality of second gas passages 42, and a plurality of power generation element units 5. . Further, the fuel cell 10 has a communication channel 30.

[Support substrate]
The support substrate 4 extends upward from the manifold 2. The support substrate 4 has a flat shape and has a base end portion 43 and a tip end portion 44. The proximal end portion 43 and the distal end portion 44 are both end portions in the length direction (x-axis direction) of the support substrate 4. In the present embodiment, the base end portion 43 of the support substrate 4 means the lower end portion, and the front end portion 44 of the support substrate 4 means the upper end portion. In the present embodiment, the support substrate 4 is longer in the length direction (x-axis direction) than in the width direction (y-axis direction), but is longer in the width direction than in the length direction. Also good.

  As shown in FIG. 5, the support substrate 4 has a first main surface 45 and a second main surface 46. The first main surface 45 and the second main surface 46 are opposite to each other. The first main surface 45 and the second main surface 46 support each power generating element unit 5. The first main surface 45 and the second main surface 46 face the thickness direction (z-axis direction) of the support substrate 4. Further, each side surface 47 of the support substrate 4 faces the width direction (y-axis direction) of the support substrate 4. Each side surface 47 may be curved.

The support substrate 4 is made of a porous material that does not have electronic conductivity. The support substrate 4 is made of, for example, CSZ (calcia stabilized zirconia). Alternatively, the support substrate 4 may be made of NiO (nickel oxide) and YSZ (8YSZ) (yttria-stabilized zirconia), or made of NiO (nickel oxide) and Y ₂ O ₃ (yttria). Alternatively, MgO (magnesium oxide) and MgAl ₂ O ₄ (magnesia alumina spinel) may be used. The porosity of the support substrate 4 is, for example, about 20 to 60%. This porosity is measured, for example, by Archimedes method or microstructure observation.

  The support substrate 4 is covered with a dense layer 48. The dense layer 48 is configured to prevent the gas diffused into the support substrate 4 from the first gas channel 41 and the second gas channel 42 from being discharged to the outside. In the present embodiment, the dense layer 48 covers the first main surface 45, the second main surface 46, and the side surfaces 47 of the support substrate 4. In the present embodiment, the dense layer 48 is constituted by an electrolyte 7 and an interconnector 91 described later. The dense layer 48 is denser than the support substrate 4. For example, the porosity of the dense layer 48 is about 0 to 7%.

[First and second gas flow paths]
As shown in FIG. 4, the plurality of first gas passages 41 and the plurality of second gas passages 42 are formed in the support substrate 4. The first and second gas flow paths 41 and 42 extend from the base end portion 101 of the fuel cell 10 toward the tip end portion 102. In the present embodiment, the first and second gas flow paths 41 and 42 extend in the vertical direction in the support substrate 4. The first and second gas flow paths 41 and 42 penetrate the support substrate 4.

  The first gas flow paths 41 are arranged at intervals in the width direction (y-axis direction) of the support substrate 4. It is preferable that the first gas flow paths 41 are arranged at substantially equal intervals. Further, the second gas flow paths 42 are arranged at intervals from each other in the width direction (y-axis direction) of the support substrate 4. The second gas flow paths 42 are preferably arranged at substantially equal intervals.

  The first gas channel 41 has a proximal end portion 411 and a distal end portion 412. The base end portion 411 of the first gas channel 41 is located on the manifold 2 side. Further, the distal end portion 412 of the first gas channel 41 is an end portion on the opposite side of the proximal end portion 411. In the present embodiment, the lower end portion of the first gas flow path 41 is the base end portion 411, and the upper end portion of the first gas flow passage 41 is the distal end portion 412.

  The second gas flow path 42 has a proximal end portion 421 and a distal end portion 422. The base end portion 421 of the second gas channel 42 is located on the manifold 2 side. Further, the distal end portion 422 of the second gas flow path 42 is an end portion on the opposite side of the proximal end portion 421. In the present embodiment, the lower end portion of the second gas flow path 42 is the base end portion 421, and the upper end portion of the second gas flow path 42 is the distal end portion 422.

  The first gas channel 41 communicates with the gas supply chamber 21 of the manifold 2 through the first divided hole 234a. The second gas flow path 42 communicates with the gas recovery chamber 22 of the manifold 2 through the second divided hole 234b.

  As shown in FIG. 4, the first gas channel 41 and the second gas channel 42 communicate with each other at the tip 102 of the fuel cell 10. That is, the first gas channel 41 and the second gas channel 42 communicate with each other at the respective tip portions 412 and 422. Specifically, the first gas channel 41 and the second gas channel 42 communicate with each other via the communication channel 30.

Total flow path cross-sectional area of each first gas flow passage 43 may be greater than the total flow path cross-sectional area of each of the second gas flow path 44.

[Power generation element]
As shown in FIG. 5, each power generating element unit 5 is supported by the first main surface 45 and the second main surface 46 of the support substrate 4. The number of power generation element portions 5 formed on the first main surface 45 and the number of power generation element portions 5 formed on the second main surface 46 may be the same or different from each other. Moreover, the magnitude | size of each electric power generation element part 5 may mutually differ.

  Each power generating element unit 5 is arranged along the direction (x-axis direction) in which the first and second gas flow paths 41 and 42 extend. Specifically, the power generating element portions 5 are arranged on the support substrate 4 with a space from each other toward the distal end portion 44 from the proximal end portion 43. That is, the power generating element portions 5 are arranged at intervals along the length direction (x-axis direction) of the support substrate 4. In addition, each electric power generation element part 5 is mutually connected in series by the electrical connection part 9 mentioned later.

  The power generation element unit 5 extends in the width direction (y-axis direction) of the support substrate 4. The power generating element portion 5 is partitioned into a first portion 51 and a second portion 52 in the width direction of the support substrate 4. There is no strict boundary between the first portion 51 and the second portion 52. For example, in a state where the fuel cell 10 is attached to the manifold 2, a portion overlapping with the boundary between the gas supply chamber 21 and the gas recovery chamber 22 in the length direction view (x-axis direction view) of the support substrate 4 is The boundary portion between the first portion 51 and the second portion 52 can be used.

  The first gas channel 41 overlaps the first portion 51 of the power generation element unit 5 in the thickness direction view (z-axis direction view) of the support substrate 4. For this reason, the fuel gas is mainly supplied from the first gas flow paths 41 to the first portion 51 of the power generation element unit 5. Further, the second gas flow path 42 overlaps the second portion 52 of the power generation element unit 5 in the thickness direction view (z-axis direction view) of the support substrate 4. For this reason, the fuel gas is mainly supplied from the second gas passages 42 to the second portion 52 of the power generation element unit 5. In addition, some 1st gas flow paths 41 do not need to overlap with the 1st part 51 among several 1st gas flow paths 41. As shown in FIG. Similarly, some of the second gas passages 42 among the plurality of second gas passages 42 may not overlap the second portion 52.

  FIG. 6 is a cross-sectional view of the fuel battery cell 10 cut along the first gas flow path 41. The cross-sectional view of the fuel cell 10 cut along the second gas flow path 42 is the same as FIG. 6 except that the cross-sectional area of the second gas flow path 42 is different.

  The power generation element unit 5 includes a fuel electrode 6, an electrolyte 7, and an air electrode 8. The power generating element unit 5 further includes a reaction preventing film 11. The fuel electrode 6 is a fired body made of a porous material having electron conductivity. The fuel electrode 6 includes a fuel electrode current collector 61 and a fuel electrode active part 62.

  The fuel electrode current collector 61 is disposed in the recess 49. The recess 49 is formed in the support substrate 4. Specifically, the fuel electrode current collector 61 is filled in the recess 49 and has the same outer shape as the recess 49. Each fuel electrode current collector 61 has a first recess 611 and a second recess 612. The anode active part 62 is disposed in the first recess 611. Specifically, the fuel electrode active part 62 is filled in the first recess 611.

The fuel electrode current collector 61 can be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode current collector 61 may be composed of NiO (nickel oxide) and Y ₂ O ₃ (yttria), or composed of NiO (nickel oxide) and CSZ (calcia stabilized zirconia). Also good. The thickness of the fuel electrode current collector 61 and the depth of the recess 49 are about 50 to 500 μm.

  The fuel electrode active part 62 may be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode active part 62 may be composed of NiO (nickel oxide) and GDC (gadolinium-doped ceria). The thickness of the fuel electrode active part 62 is 5 to 30 μm.

  The electrolyte 7 is disposed so as to cover the fuel electrode 6. Specifically, the electrolyte 7 extends in the length direction from one interconnector 91 to another interconnector 91. That is, the electrolyte 7 and the interconnector 91 are alternately arranged in the length direction (x-axis direction) of the support substrate 4. The electrolyte 7 covers the first main surface 45, the second main surface 46, and the side surfaces 47 of the support substrate 4.

  The electrolyte 7 is denser than the support substrate 4. For example, the porosity of the electrolyte 7 is about 0 to 7%. The electrolyte 7 is a fired body made of a dense material that has ionic conductivity and no electronic conductivity. The electrolyte 7 can be made of, for example, YSZ (8YSZ) (yttria stabilized zirconia). Or you may comprise from LSGM (lantern gallate). The thickness of the electrolyte 7 is, for example, about 3 to 50 μm.

The reaction preventing film 11 is a fired body composed of a dense material. The reaction preventing film 11 has substantially the same shape as the fuel electrode active portion 62 in plan view. The reaction preventing film 11 is disposed at a position corresponding to the fuel electrode active part 62 through the electrolyte 7. The reaction preventing film 11 suppresses occurrence of a phenomenon in which YSZ in the electrolyte 7 and Sr in the air electrode 8 react to form a reaction layer having a large electric resistance at the interface between the electrolyte 7 and the air electrode 8. Is provided. The reaction preventing film 11 can be made of, for example, GDC = (Ce, Gd) O ₂ (gadolinium-doped ceria). The thickness of the reaction preventing film 11 is, for example, about 3 to 50 μm.

The air electrode 8 is disposed on the reaction preventing film 11. The air electrode 8 is a fired body made of a porous material having electron conductivity. The air electrode 8 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, from LSF = (La, Sr) FeO ₃ (lanthanum strontium ferrite), LNF = La (Ni, Fe) O ₃ (lanthanum nickel ferrite), LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite), etc. It may be configured. Moreover, the air electrode 8 may be comprised by two layers, the 1st layer (inner layer) comprised from LSCF, and the 2nd layer (outer layer) comprised from LSC. The thickness of the air electrode 8 is, for example, 10 to 100 μm.

[Electrical connection]
The electrical connection portion 9 is configured to electrically connect adjacent power generation element portions 5. The electrical connection unit 9 includes an interconnector 91 and an air electrode current collector film 92. The interconnector 91 is disposed in the second recess 612. Specifically, the interconnector 91 is embedded (filled) in the second recess 612. The interconnector 91 is a fired body composed of a dense material having electronic conductivity. The interconnector 91 is denser than the support substrate 4. For example, the porosity of the interconnector 91 is about 0 to 7%. The interconnector 91 can be composed of, for example, LaCrO ₃ (lanthanum chromite). Alternatively, it may be composed of (Sr, La) TiO ₃ (strontium titanate). The thickness of the interconnector 91 is, for example, 10 to 100 μm.

  The air electrode current collector film 92 is disposed so as to extend between the interconnector 91 and the air electrode 8 of the adjacent power generation element portions 5. For example, the air electrode current collector is connected so as to electrically connect the air electrode 8 of the power generating element unit 5 arranged on the left side of FIG. 6 and the interconnector 91 of the power generating element unit 5 arranged on the right side of FIG. A membrane 92 is disposed. The air electrode current collector film 92 is a fired body made of a porous material having electron conductivity. The air electrode current collector 82 may or may not have oxygen ion conductivity.

The air electrode current collector film 92 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite) may be used. Or you may comprise from Ag (silver) and Ag-Pd (silver palladium alloy). The thickness of the air electrode current collector film 92 is, for example, about 50 to 500 μm.

[Communication member]
As shown in FIG. 4, the communication member 3 is attached to the distal end portion 44 of the support substrate 4. The communication member 3 has a communication channel 30 that communicates the first gas channel 41 and the second gas channel 42. Specifically, the communication channel 30 communicates the tip portion 412 of each first gas channel 41 and the tip portion 422 of each second gas channel 42. The communication channel 30 is configured by a space extending from each first gas channel 41 to each second gas channel 42. The communication member 3 is preferably joined to the support substrate 4. The communication member 3 is preferably formed integrally with the support substrate 4.

  The communication member 3 is porous, for example. Further, the communication member 3 has a dense layer 31 that constitutes the outer surface thereof. The dense layer 31 is formed more densely than the main body of the communication member 3. For example, the porosity of the dense layer 31 is about 0 to 7%. The dense layer 31 can be formed of the same material as the communication member 3, the material used for the electrolyte 7 described above, crystallized glass, or the like.

  As shown in FIG. 1, each fuel cell 10 is arranged so that the principal surfaces face each other. In addition, the fuel cells 10 are arranged along the arrangement direction (z-axis direction). In the present embodiment, the fuel cells 10 are arranged at equal intervals along the arrangement direction, but may not be at equal intervals.

[Fuel battery cell mounting structure]
As shown in FIG. 4, the base end surface 103 of the fuel cell 10 faces the top plate 231. That is, the base end portion 101 of the fuel cell 10 is not inserted into the through hole 234. As shown in FIG. 7, the base end surface 103 of the fuel battery cell 10 covers the through hole 234. The first divided hole 234 a communicates with the plurality of first gas flow paths 41. The second divided hole 234 b communicates with the plurality of second gas flow paths 42. The connection reinforcing portion 236 is opposed to the region between the first gas flow channel 41 and the second gas flow channel 42 in the base end surface 103 of the fuel cell 10 via the bonding material 104. . In this embodiment, the base end surface 103 of the fuel cell 10 means a lower end surface.

  The through-hole 234 has a dimension in the arrangement direction (z-axis direction) larger than the diameter of each gas flow path 41, 42. Specifically, the first divided holes 234 a have a dimension in the arrangement direction that is larger than the diameter of the first gas channel 41. Further, the second divided hole 234 b has a dimension in the arrangement direction larger than the diameter of the second gas flow path 43. Thus, even if the position of the base end portion 101 of the fuel cell 10 is slightly deviated from the design value due to deformation of the fuel cell 10 or the like, the through hole 234 and each gas flow channel 41 , 42 can be maintained in communication with each other.

  The base end surface 103 of the fuel cell 10 has an outer peripheral edge portion and a central portion surrounded by the outer peripheral edge portion. A central portion of the base end surface 103 faces the through hole 234. That is, the base end surface 103 of the fuel cell 10 is slightly larger than the through hole 234 in plan view (viewed in the x-axis direction).

  As shown in FIG. 8, the base end portion 101 of the fuel battery cell 10 is fixed to the top plate 231 with a bonding material 104. The bonding material 104 is formed in an annular shape along the base end portion 101 of the fuel battery cell 10.

  As shown in FIG. 9, the bonding material 104 is filled in a gap between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2. As shown in FIG. 10, the bonding material 104 is filled between the outer peripheral edge of the base end surface 103 and the top plate 231. The bonding material 104 is not filled between the central portion of the base end surface 103 and the top plate 231. That is, between the first gas flow path 41 and the second gas flow path 42 and the through hole 234 so that the first gas flow path 41 and the second gas flow path 42 and the through hole 234 communicate with each other. The bonding material 104 is not filled.

  As shown in FIG. 9, the bonding material 104 has a central region A1 located at the center in the width direction of the fuel cell 10 and an end region A2 located at the end in the width direction. The central region A1 of the bonding material 104 refers to a region near the center in the width direction of the fuel cell 10 in the bonding material 104 filled between the base end surface 103 of the fuel cell 10 and the top plate 231. Specifically, the central region A1 of the bonding material 104 refers to a central region of the bonding material 104 divided into five equal parts in the width direction (y-axis direction) of the fuel cell 10. Further, the end region A <b> 2 of the joint portion 104 is a region of the end portion of the joint material 104 divided into five equal parts in the width direction of the fuel cell 10.

  The pore diameter in the central region A1 is larger than the pore diameter in the end region A2. For example, the pore diameter in the central region A1 is about 0.01 to 0.95 mm. Further, the pore diameter in the end region A2 is about 0.005 to 0.25 mm. The pore diameter in the central region A1 is about 1.1 to 100 times the pore diameter in the end region A2. The pore diameter in the central area A1 is larger than the pore diameter in the other areas.

  The pore diameter is the value of the equivalent circle diameter of the pores. The value of the equivalent circle diameter of the pores can be obtained by image analysis of the cross-sectional image of the bonding material 104. The equivalent circle diameter means the diameter of a perfect circle corresponding to the pore area determined by image analysis of the cross-sectional image of the bonding material 104.

  Specifically, first, the bonding material 104 filled in the gap between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 is a surface parallel to the main surface of the fuel cell 10 (XY plane). ) To form a cross section of the bonding material 104.

  The cross section of the bonding material 104 is photographed with an FE-SEM to create a cross-sectional image of the bonding material 104. In addition, when image | photographing by FE-SEM, the base end surface 103 of the fuel cell 10 and the top plate 231 are expanded in the range which can be settled in the visual field of FE-SEM.

  The cross-sectional image photographed by this FE-SEM is analyzed by image analysis software HALCON manufactured by MVTec. Note that the entire range of the central area A1 and the end area A2 is analyzed by the image analysis software. Of the pore diameters obtained by analyzing each of the central region A1 and the end region A2, ten are selected in order from the largest pore size in each of the central region A1 and the end region A2. The average of the 10 pore diameters is defined as the pore diameter of each of the central region A1 and the end region A2. Note that the larger the pore diameter, the higher the stress relaxation effect.

  In addition, the pore diameter in the center region A1 and the end region A2 can be controlled, for example, by adjusting the size of the pore former containing an organic component added before the heat treatment.

  As shown in FIG. 4, the bonding material 104 is filled between the connection reinforcing portion 236 and the base end surface 103 of the fuel cell 10. For this reason, it is possible to prevent the fuel gas in the gas supply chamber 21 from flowing into the gas recovery chamber 22 through the gap between the connection reinforcing portion 236 and the base end surface 103 of the fuel cell 10.

The bonding material 104 is, for example, crystallized glass. As the crystallized glass, for example, a SiO ₂ —B ₂ O ₃ system, a SiO ₂ —CaO system, or a SiO ₂ —MgO system can be employed. In this specification, crystallized glass means that the ratio (crystallinity) of “volume occupied by crystal phase” to the total volume is 60% or more, and “volume occupied by amorphous phase and impurities relative to the total volume”. "Indicates a glass having a ratio of less than 40%. Note that amorphous glass, brazing material, ceramics, or the like may be employed as the material of the bonding material 104. Specifically, the bonding material 104 is at least one selected from the group consisting of SiO ₂ —MgO—B ₂ O ₅ —Al ₂ O ₃ and SiO ₂ —MgO—Al ₂ O ₃ —ZnO.

  As shown in FIG. 9, the distance between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 is different in the width direction (y-axis direction) of the fuel cell 10. The distance d1 between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 at the center in the width direction of the fuel cell 10 is the base end surface of the fuel cell 10 at the end of the fuel cell 10 in the width direction. It is larger than the distance d2 between 103 and the top plate 231 of the manifold 2.

  The distance between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 gradually increases from both ends in the width direction (y-axis direction) toward the center. The base end surface 103 of the fuel cell 10 is curved so that the center portion in the width direction (y-axis direction) is farther from the top plate 231 than both end portions in the width direction. For example, the base end surface 103 is formed in an arc shape when the fuel cell 10 is viewed from the front (z-axis direction view).

  In this embodiment, the base end surface 103 of the fuel cell 10 is in contact with the top plate 231 at both ends in the width direction. Specifically, the base end surface 103 of the fuel battery cell 10 is in contact with the top plate 231 at a part of both end portions in the width direction.

  The distance d1 between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 at the center in the width direction of the fuel cell 10 is, for example, about 0.02 to 1 mm. This distance d1 is obtained by, for example, measuring the distance between the base end surface 103 of the center portion of the fuel cell 10 equally divided into 5 in the width direction and the top plate 231 at any three locations and averaging them. .

  The distance d2 between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 at the end in the width direction of the fuel cell 10 is, for example, about 0.01 to 0.3 mm. This distance d2 is obtained by, for example, measuring the distance between the base end surface 103 of the end portion of the fuel cell 10 that is equally divided in the width direction and the top plate 231 at an arbitrary three locations and averaging them. .

[Power generation method]
In the cell stack apparatus 100 configured as described above, a fuel gas such as hydrogen gas is supplied to the gas supply chamber 21 of the manifold 2 and the fuel cell 10 is exposed to a gas containing oxygen such as air. Then, the chemical reaction shown in the following formula (1) occurs in the air electrode 8, the chemical reaction shown in the following formula (2) occurs in the fuel electrode 6, and a current flows.
(1/2) · O ₂ + 2e ⁻ → O ²⁻ (1)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (2)

  Specifically, the fuel gas supplied to the gas supply chamber 21 flows through the first gas flow path 41 of each fuel cell 10, and is expressed by the above formula (2) at the fuel electrode 6 of each power generation element unit 5. A chemical reaction occurs. The unreacted fuel gas in each fuel electrode 6 exits the first gas channel 41 and is supplied to the second gas channel 42 via the communication channel 30. The fuel gas supplied to the second gas flow path 42 again undergoes a chemical reaction represented by the above formula (2) in the fuel electrode 6. The unreacted fuel gas in the fuel electrode 6 in the process of flowing through the second gas flow path 42 is recovered to the gas recovery chamber 22 of the manifold 2.

[Modification]
As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention.

Modification 1
In the said embodiment, although the pore diameter in center area | region A1 is larger than the pore diameter in edge part area | region A2, it is not limited to this. For example, the pore diameter in the central region A1 may be smaller than the pore diameter in the end region A2. In this case, the porosity in the central region A1 is larger than the porosity in the end region A2.

  For example, the porosity in the central region A1 is about 5 to 60%. And the porosity in edge part area | region A2 is about 0.5 to 20%. The porosity in the central region A1 is about 4 to 50% larger than the porosity in the end region A2. Note that the porosity in the central region A1 is larger than the porosity in other regions.

  The porosity is obtained by image analysis of a cross-sectional image of the bonding material 104. Specifically, a cross-sectional image of the bonding material 104 is created by FE-SEM by a method similar to the method for obtaining the pore diameter described above. Then, the cross-sectional image of the bonding material 104 is subjected to image analysis by image analysis software HALCON manufactured by MVTec. On the cross-sectional image after this image analysis, the area occupancy rates of the material portion and the pore portion constituting the bonding material 104 are obtained, and the area occupancy rate of the pore portion is defined as the porosity. The porosity is calculated for the entire range of each of the central region A1 and the end region A2.

  In addition, the porosity in center area | region A1 and edge part area | region A2 can be controlled by adjusting the magnitude | size and volume (volume ratio) of the pore making material containing the organic component added before heat processing, for example.

Modification 2
The pore diameter in the central region A1 may be larger than the pore diameter in the end region A2, and the porosity in the central region A1 may be larger than the porosity in the end region A2.

Modification 3
In the above embodiment, the base end surface 103 of the fuel cell 10 is curved, but the present invention is not limited to this. For example, as shown in FIG. 11, the top plate 231 may be curved. That is, the top plate 231 is curved so that the center portion in the width direction is farther from the base end surface 103 of the fuel cell 10 than both ends in the width direction. For example, when the fuel cell 10 is viewed from the front (as viewed in the z-axis direction), the crosspiece 235 of the top plate 231 is curved in an arc shape.

  As shown in FIG. 12, the base end surface 103 of the fuel battery cell 10 may be curved, and the crosspiece 235 of the top plate 231 may be curved.

Modification 4
In the above embodiment, the distance d1 between the base end surface 103 of the fuel cell 10 and the top plate 231 of the manifold 2 at the center in the width direction of the fuel cell 10 is the fuel cell at the end of the fuel cell 10 in the width direction. Although it is larger than the distance d2 between the base end face 103 of the cell 10 and the top plate 231 of the manifold 2, it is not limited to this.

  For example, as shown in FIG. 13, the distance between the base end surface 103 of the fuel cell 10 and the top plate 231 may be substantially constant in the width direction. Further, the distance between the base end surface 103 of the fuel cell 10 and the top plate 231 may be larger at the end than at the center in the width direction of the fuel cell 10.

Modification 5
In the above embodiment, the connection reinforcing portion 236 faces the base end surface 103 in the boundary region 403 of the fuel cell 10, but is not limited to this. The connection reinforcing portion 236 may be formed at a position facing the base end surface 103 in the first region 401 or the second region 402.

Modification 6
As shown in FIG. 14, the bonding material 104 may protrude between the through hole 234 and the first or second gas flow path 41, 42 so that a part thereof overlaps the through hole 234. A part of the bonding material 104 may cover the inner wall surfaces of the base end portions 411 and 421 of the first or second gas flow paths 41 and 42. The bonding material 104 can improve the strength of the base end portions 411 and 421 of the first or second gas flow paths 41 and 42.

  Further, a part of the bonding material 104 may cover at least a part of the inner wall surface of the through hole 234. Thereby, it can suppress that the joining material 104 peels from the top plate 231. FIG.

Modification 7
As shown in FIG. 15, the cell stack device 100 may not include the communication member 3. In this case, for example, the communication channel 30 may be formed in the support substrate 4. The communication channel 30 extends in the width direction (y-axis direction) at the distal end portion 44 of the support substrate 4.

Modification 8
In the above embodiment, the through hole 234 is divided into a plurality of divided holes 234a, but the configuration of the through hole 234 is not limited to this. For example, as shown in FIG. 16, the through hole 234 may not be divided into a plurality of divided holes 234a. That is, the top plate 231 does not have to include the connection reinforcing portion 236.

Modification 7
The fuel cell 10 of the above embodiment is a so-called horizontal stripe type fuel cell in which the power generation element portions 5 are arranged in the length direction (x-axis direction) of the support substrate 4. The configuration is not limited to this. For example, the fuel battery cell 10 may be a so-called vertical stripe type fuel battery cell in which one power generation element portion 5 is supported on the first main surface 45 of the support substrate 4. In this case, one power generation element portion 5 may be supported on the second main surface 46 of the support substrate 4 or may not be supported.

Modification 8
In the above embodiment, the off gas from the fuel cell 10 is recovered by the gas recovery chamber 22 of the manifold 2, but is not limited thereto. For example, off-gas may be discharged from the tip of the fuel cell 10 and burned. In this case, the manifold 2 does not have the partition plate 24 and may not be divided into the gas supply chamber 21 and the gas recovery chamber 22.

2 Manifold 231 Top plate 234 Through hole 10 Fuel cell 103 Base end face 104 Joining material A1 Central area A2 End area

Claims (8)

A manifold having a top plate including a through hole;
A plate-like fuel cell having a base end surface facing the top plate of the manifold so as to cover the through hole, and extending from the manifold;
Filled in the gap between the top plate of the manifold and the base end surface of the fuel cell, a bonding material for bonding the manifold and the fuel cell,
With
The bonding material has a central region located at a central portion in the width direction of the fuel cell, and an end region located at an end portion in the width direction,
The pore diameter in the central region is larger than the pore diameter in the end region,
Cell stack device.
The distance between the base end surface of the fuel cell in the center portion in the width direction and the top plate is larger than the distance between the base end surface of the fuel cell in the end portion in the width direction and the top plate.
The cell stack device according to claim 1.
The distance between the base end surface of the fuel cell and the top plate of the manifold gradually increases from both ends in the width direction toward the center.
The cell stack apparatus according to claim 2.
The base end surface of the fuel cell is curved so that a center portion in the width direction is farther from the top plate than both end portions in the width direction.
The cell stack device according to claim 2 or 3.
The top plate is curved so that the center portion in the width direction is farther from the base end face of the fuel cell than both ends in the width direction.
The cell stack device according to any one of claims 2 to 4.
The base end surface of the fuel cell contacts the top plate at both ends in the width direction.
The cell stack device according to claim 2.
The porosity in the central region is greater than the porosity in the end region,
The cell stack device according to claim 1.
A manifold having a top plate including a through hole;
A plate-like fuel cell having a base end surface facing the top plate of the manifold so as to cover the through hole, and extending from the manifold;
Filled in the gap between the top plate of the manifold and the base end surface of the fuel cell, a bonding material for bonding the manifold and the fuel cell,
With
The bonding material has a central region located at a central portion in the width direction of the fuel cell, and an end region located at an end portion in the width direction,
The porosity in the central region is greater than the porosity in the end region,
Cell stack device.

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