JP6309151B1 - End current collecting member and cell stack device - Google Patents

Abstract

An end current collecting member is prevented from being short-circuited due to contact with a metal part. An end current collecting member is configured to take out electric power from a fuel cell. The end current collecting member 3 includes a joining portion 31, a drawing portion 32, and an insulating layer 33. The joining portion 31 is configured to be joined to the fuel cell. The lead portion 32 extends from the joint portion 31. The insulating layer 33 covers the lead portion 32. [Selection] Figure 7

Description

  The present invention relates to an end current collecting member and a cell stack device.

  The cell stack device includes a housing, a fuel cell, and a manifold (Patent Document 1). The fuel battery cell and the manifold are disposed in the housing. The fuel cell extends upward from the manifold. The manifold supplies fuel gas to the gas flow path of the fuel battery cell. In addition, oxygen-containing gas (such as air) is supplied to the outer surface of the fuel cell. The fuel cell generates electric power using fuel gas and air. The electric power generated by the fuel battery cell is taken out to an external circuit by an end current collecting member electrically connected to the fuel battery cell.

Japanese Patent Application Laid-Open No. 2006-171064

  The end current collecting member extends from the inside of the housing to the outside. Since the casing is generally made of a metal material, there is a possibility that problems such as a short circuit may occur when the end current collecting member comes into contact with the casing. Moreover, the problem of a short circuit may occur similarly when the end current collecting member comes into contact with a metal part other than the casing.

  An object of the present invention is to prevent an end current collecting member from short-circuiting due to contact with a metal part.

  The end current collecting member according to the first aspect of the present invention is configured to extract electric power from the fuel cell. The end current collecting member includes a joint portion, a lead portion, and an insulating layer. The joining portion is configured to be joined to the fuel battery cell. The drawer portion extends from the joint portion. The insulating layer covers the drawer portion.

  According to this configuration, the drawer portion extends from the joint portion for connection to an external circuit. And the insulating layer is formed so that this drawer | drawing-out part may be covered. For this reason, an insulating layer contacts metal parts, such as a housing | casing, and a drawer | drawing-out part does not contact directly. As a result, it is possible to prevent a short circuit due to contact of the end current collecting member with the metal part. Moreover, since the drawer part is covered with the insulating layer, oxidation of the drawer part can be suppressed. As a result, it is possible to suppress an increase in resistance in the drawer portion due to oxidation.

  Preferably, the end current collecting member further includes a conductive layer covering the joint portion. When the joint portion is made of a material containing chromium such as stainless steel, the power generation element portion of the fuel cell may be poisoned by chromium volatilized from the joint portion. On the other hand, since the joining portion is covered with the conductive layer, the volatilization of chromium is suppressed, and as a result, poisoning of the power generation element portion of the fuel cell can be suppressed.

  Preferably, the insulating layer is made of an insulating ceramic.

  Preferably, the joining portion is made of a metal material containing iron and chromium.

  Preferably, the joint portion and the drawer portion are configured by one member.

  Preferably, the joining portion and the drawing portion are made of a single metal plate. For example, when the joining portion and the drawer portion are composed of different members, a location where the joint portion and the drawer portion are joined is generated. Then, a power loss due to the generation of resistance at this junction becomes a problem. On the other hand, when a junction part and a drawer | drawing-out part are comprised from the metal plate of 1 sheet, the junction location as mentioned above does not arise. For this reason, the resistance in a joining location does not generate | occur | produce and the power loss at the time of taking out an electric current from a fuel battery cell outside can be reduced more.

  The cell stack device according to the second aspect of the present invention includes a housing, a manifold, a fuel cell, and any one of the end current collecting members. The housing has an extraction hole. The manifold is disposed in the housing. The fuel cell is disposed in the housing and extends upward from the manifold. The end current collecting member is electrically connected to the fuel battery cell. The lead-out portion of the end current collecting member extends to the outside of the housing through the take-out hole of the housing.

  Preferably, the drawer has a second portion extending along the upper surface of the manifold. And the 2nd part is inclined and extended so that it may leave | separate from the upper surface of a manifold as it leaves | separates from a junction part.

  Preferably, the drawer has a second portion extending along the upper surface of the manifold. And the 2nd part inclines and extends so that it may approach the upper surface of a manifold as it leaves | separates from a junction part.

  Preferably, the joining portion and the drawing portion have an oxide film on the surface. And the oxide film of a drawer | drawing-out part is thinner than the oxide film of a junction part. According to this configuration, the end current collecting member can be protected by the oxide film. Moreover, the electrical resistance in a drawer part can be made low by making the oxide film of a drawer part thin.

  Preferably, the cell stack device further includes a first bonding material for bonding the fuel cell and the bonding portion. The joining portion has a base material made of an alloy containing Cr and a chromium oxide film covering the base material. In a cross section perpendicular to the outer surface of the fuel cell, the joint includes a first surface having an angle with respect to the outer surface, a second surface having an angle with respect to the outer surface, a first surface, and a second surface. And a corner portion formed by. The corner portion is closer to the outer surface than each of the first surface and the second surface.

  According to the present invention, it is possible to prevent the end current collecting member from being short-circuited by coming into contact with the metal part.

The perspective view of a cell stack apparatus. Sectional drawing of a cell stack apparatus. The perspective view of a fuel cell. Sectional drawing of a fuel cell. The expanded sectional view of a cell stack device. The perspective view of an edge part current collection member. Sectional drawing of an edge part current collection member. The perspective view of the edge part current collection member which concerns on a modification. The side sectional view of the end current collection member concerning a modification. The perspective view of the edge part current collection member which concerns on a modification. The perspective view of the edge part current collection member which concerns on a modification. The perspective view of the edge part current collection member which concerns on a modification. The expanded sectional view of the cell stack apparatus concerning a modification. The side sectional view of the end current collection member concerning a modification. The side sectional view of the end current collection member concerning a modification. The side sectional view of the end current collection member concerning a modification. The side sectional view of the end current collection member concerning a modification.

[Cell stack equipment]
Embodiments of an end current collecting member and a cell stack device according to the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, the cell stack device 100 includes a plurality of fuel cells 1, a manifold 2, and a pair of end current collecting members 3. The cell stack apparatus 100 is covered with a casing 90. The housing 90 is made of a metal material. For example, the housing 90 is made of ferritic stainless steel, austenitic stainless steel, Ni-based alloy, or the like.

[Manifold]
The manifold 2 is configured to distribute gas to each fuel cell 1. The manifold 2 is hollow and has an internal space. A gas such as fuel gas is supplied to the internal space of the manifold 2 through the introduction pipe 201. The manifold 2 has a plurality of through holes 27 that allow the internal space to communicate with the outside.

  The manifold 2 supports each fuel cell 1. The manifold 2 includes a manifold body 21 and an upper wall 22. The manifold body 21 and the upper wall 22 are separate members and are joined to each other. The manifold body 21 and the upper wall 22 may be integrally formed. The manifold body 21 and the upper wall 22 define an internal space of the manifold 2.

  The manifold body 21 has a rectangular parallelepiped shape and has an internal space whose upper surface is open. Specifically, the manifold body 21 has a bottom wall 23 and a side wall 24. The side wall 24 extends upward from the peripheral edge of the bottom wall 23. The introduction pipe 201 is attached to the side wall 24 and communicates with the internal space of the manifold 2. The introduction pipe 201 extends upward, for example.

For example, the manifold body 21 is formed of a metal having heat resistance or insulating ceramics. More specifically, the manifold body 21 is made of ferritic stainless steel, austenitic stainless steel, Ni-based alloy, MgO (magnesium oxide), Al ₂ O ₃ (aluminum oxide), MgAl ₂ O ₄ (magnesia alumina spinel), It is formed of at least one selected from the group consisting of MgO · SiO ₂ (steatite) and 2MgO · SiO ₂ (forsterite).

  The upper wall 22 is attached to the manifold body 21 so as to block the upper surface of the manifold body 21. For example, the upper wall 22 and the manifold body 21 are joined by crystallized glass or the like. The upper wall 22 can be formed from at least one of the materials of the manifold body 21 described above.

  The upper wall 22 is configured such that each fuel cell 1 is attached. Specifically, the upper wall 22 has a plurality of through holes 27. Each through hole 27 extends in the width direction (y-axis direction) of the manifold 2. Moreover, each through-hole 27 is arrange | positioned at intervals in the sequence direction (z-axis direction).

[Fuel battery cell]
Each fuel cell 1 extends upward from the manifold 2. Specifically, each fuel cell 1 extends upward from the upper wall 22 of the manifold 2. The lower end portion of the fuel battery cell 1 is inserted into the through hole 27. The lower end portion of the fuel cell 1 may protrude downward from the upper wall 22. The length of the fuel cell in the longitudinal direction (x-axis direction) can be, for example, about 100 to 300 mm. In the state where the lower end portion of the fuel cell 1 is inserted into the through hole 27, a gap is formed between the outer peripheral surface of the lower end portion of the fuel cell 1 and the inner wall surface of the through hole 27. This gap may be filled with a third bonding material 103 described later.

  The fuel cells 1 are arranged at intervals from each other along the arrangement direction (z-axis direction). In addition, although it is preferable that each fuel cell 1 is arrange | positioned at equal intervals along the sequence direction, it does not need to be arrange | positioned at equal intervals.

  As shown in FIG. 3, the fuel cell 1 includes a plurality of power generation element portions 11 and a support substrate 12.

[Support substrate]
The support substrate 12 extends upward from the manifold 2. That is, the support substrate 12 extends in the vertical direction. The support substrate 12 has a plurality of gas flow paths 121 extending in the longitudinal direction (x-axis direction) of the support substrate 12 inside. The gas flow paths 121 are arranged at intervals from each other in the width direction (y-axis direction) of the support substrate 12. The gas flow path 121 communicates with the internal space of the manifold 2.

  The longitudinal direction (x-axis direction) of the support substrate 12 is the same direction as the longitudinal direction of the fuel cell 1. Each gas channel 121 extends substantially parallel to each other. Each gas flow path 121 is open at both end faces in the longitudinal direction of the support substrate 12.

  As shown in FIG. 4, the support substrate 12 has a plurality of first recesses 123. Each first recess 123 is formed on both surfaces of the support substrate 12. The first recesses 123 are arranged at intervals in the longitudinal direction of the support substrate 12.

The support substrate 12 is made of a porous material that does not have electronic conductivity. The support substrate 12 can be made of, for example, CSZ (calcia stabilized zirconia). Alternatively, the support substrate 12 may be composed of NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia), or composed 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 12 is, for example, about 20 to 60%.

[Power generation element]
Each power generating element portion 11 is supported on both surfaces of the support substrate 12. Each power generation element unit 11 may be supported only on one side of the support substrate 12. The respective power generation element portions 11 are arranged in the longitudinal direction (x-axis direction) of the fuel battery cell 1. That is, the respective power generation element portions 11 are arranged in the vertical direction. The fuel cell 1 according to the present embodiment is a so-called horizontal stripe fuel cell.

  Each power generation element portion 11 includes a power generation element main body portion 110 and an electrical connection portion 111. The power generation element main body 110 includes a fuel electrode 13, an electrolyte 14, and an air electrode 15. Each power generation element unit 11 further includes a reaction preventing film 16. The fuel electrode 13 is a fired body made of a porous material having electron conductivity. The fuel electrode 13 includes a fuel electrode current collector 131 and a fuel electrode active part 132.

  The fuel electrode current collector 131 is disposed in the first recess 123. Specifically, the fuel electrode current collector 131 is filled in the first recess 123 and has the same outer shape as the first recess 123. Each fuel electrode current collector 131 has a second recess 131a and a third recess 131b. The anode active part 132 is disposed in the second recess 131a. Specifically, the fuel electrode active part 132 is filled in the second recess 131a.

The fuel electrode current collector 131 can be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode current collector 131 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 131 and the depth of the first recess 123 are about 50 to 500 μm.

  The fuel electrode active part 132 can be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode active part 132 may be composed of NiO (nickel oxide) and GDC (gadolinium-doped ceria). The thickness of the fuel electrode active part 132 is 5 to 30 μm.

  The electrolyte 14 is disposed so as to cover the fuel electrode 13. Specifically, the electrolyte 14 extends between the adjacent interconnectors 112 in the longitudinal direction. That is, the electrolyte 14 and the interconnector 112 are alternately arranged in the longitudinal direction of the fuel cell 1.

  The electrolyte 14 is a fired body made of a dense material that has ionic conductivity and no electronic conductivity. The electrolyte 14 can be composed of, for example, YSZ (8YSZ) (yttria stabilized zirconia). Or the electrolyte 14 may be comprised from LSGM (lanthanum gallate). The thickness of the electrolyte 14 is, for example, about 3 to 50 μm.

  The reaction preventing film 16 is a fired body composed of a dense material. The reaction preventing film 16 is disposed between the electrolyte 14 and the air electrode 15. The reaction preventing film 16 suppresses occurrence of a phenomenon in which a reaction layer having a large electric resistance is formed at the interface between the electrolyte 14 and the air electrode 15 due to a reaction between YSZ in the electrolyte 14 and Sr in the air electrode 15. Is provided.

The reaction preventing film 16 is made of a material containing ceria containing a rare earth element. The reaction preventing film 16 can be made of, for example, GDC = (Ce, Gd) O ₂ (gadolinium-doped ceria). The thickness of the reaction preventing film 16 is, for example, about 3 to 50 μm.

The air electrode 15 includes an air electrode active part 151 and an air electrode current collector 152. The air electrode active part 151 is disposed on the reaction preventing film 16. The air electrode active part 151 is a fired body made of a porous material having electronic conductivity. The air electrode active part 151 can be composed of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode active portion 151 may have LSF = (La, Sr) FeO ₃ (lanthanum strontium ferrite), LNF = La (Ni, Fe) O ₃ (lanthanum nickel ferrite), or LSC = (La, Sr) CoO. ₃ (lanthanum strontium cobaltite) or the like. The air electrode active part 151 may be configured by two layers of a first layer (inner layer) composed of LSCF and a second layer (outer layer) composed of LSC. The thickness of the air electrode active part 151 is, for example, 10 to 100 μm.

  The air electrode current collector 152 is disposed on the air electrode active part 151. The air electrode current collector 152 extends from the air electrode active part 151 toward the adjacent power generation element part 11. Specifically, the air electrode current collector 152 extends to the interconnector 112 that is the electrical connection 111 of the adjacent power generation element 11. The air electrode current collector 152 is a fired body made of a porous material having electronic conductivity.

The air electrode current collector 152 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode current collector 152 may be made of LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite). Or the air electrode current collection part 152 may be comprised from Ag (silver) and Ag-Pd (silver palladium alloy). The thickness of the air electrode current collector 152 is, for example, about 50 to 500 μm.

  Among the power generation element units 11, the remaining power generation element units 11 excluding the lower power generation element unit 11 a arranged at the lowermost side have an interconnector 112 as an electrical connection unit 111. The interconnector 112 is configured to electrically connect adjacent power generation element main body portions 110 to each other.

The interconnector 112 is disposed in the third recess 131b. Specifically, the interconnector 112 is embedded (filled) in the third recess 131b. The interconnector 112 is a fired body composed of a dense material having electronic conductivity. The interconnector 112 can be composed of, for example, LaCrO ₃ (lanthanum chromite). Alternatively, the interconnector 112 may be made of (Sr, La) TiO ₃ (strontium titanate). The thickness of the interconnector 112 is, for example, 10 to 100 μm.

  As shown in FIG. 5, among the power generation element portions 11, the lower power generation element portion 11 a disposed at the lowermost side includes a power generation element main body portion 110 and an electrical connection portion 111. In addition, when the power generation element unit 11 is disposed on both surfaces of the support substrate 12, the lower power generation element unit 11 a is disposed on each of both surfaces of the support substrate 12. The electrical connection portion 111 is electrically connected to the power generation element main body portion 110. Further, the electrical connection portion 111 extends downward from the power generation element main body portion 110. The electrical connection portion 111 of the lower power generation element portion 11 a includes a first connection portion 113 and a second connection portion 114.

  The 1st connection part 113 has the structure similar to the interconnector 112 mentioned above. That is, the first connection portion 113 is disposed in the third recess 131 b of the fuel electrode current collector 131. The 1st connection part 113 is comprised from the precise | minute material which has electronic conductivity. The first connection portion 113 can be formed of any of the materials for the interconnector 112 described above.

  The second connection portion 114 can be formed of any of the materials for the air electrode current collector 152 described above. The second connection part 114 is electrically connected to the first connection part 113. In addition, the second connection portion 114 extends downward from the first connection portion 113.

  The lower end of the fuel cell 1 is covered with a dense film 18. Specifically, the dense film 18 covers the support substrate 12. The dense film 18 extends downward from between the second connection portion 114 and the support substrate 12.

  The dense membrane 18 exhibits a gas seal function that prevents mixing of the fuel gas flowing in the space inside the dense membrane 18 and the air flowing in the space outside the dense membrane 18. In order to exhibit this gas sealing function, the porosity of the dense film 18 is, for example, 10% or less. The dense film 18 is made of insulating ceramics.

  Specifically, the dense film 18 can be constituted by the electrolyte 14 and the reaction preventing film 16 described above. The electrolyte 14 constituting the dense film 18 covers the support substrate 12 and extends from the first connecting portion 113 to the vicinity of the lower end of the support substrate 12. Further, the reaction preventing film 16 constituting the dense film 18 is disposed between the electrolyte 14 and the second connection portion 114. The dense film 18 may be composed of only the electrolyte 14 or may be composed of a material other than the electrolyte 14 and the reaction preventing film 16.

[End current collector]
As shown in FIGS. 1 and 2, the pair of end current collecting members 3 are configured to extract electric power from a cell stack including a plurality of fuel cells 1. Each end current collecting member 3 is attached to each fuel cell 1 disposed at both ends in the arrangement direction (z-axis direction) of each fuel cell 1. The pair of end current collecting members 3 are only different in attachment positions and are substantially the same in structure. Therefore, only one end current collecting member 3 will be described below.

  As shown in FIG. 5, the end current collecting member 3 is electrically connected to the lower power generation element portion 11a of the fuel cell 1 disposed at the end in the arrangement direction (z-axis direction). Specifically, the end current collecting member 3 is connected to the electrical connection portion 111 of the lower power generation element portion 11a.

  As shown in FIGS. 6 and 7, the end current collecting member 3 includes a joint portion 31 and a drawer portion 32. The end current collecting member 3 further includes an insulating layer 33 and a conductive layer 34. The joint portion 31 is covered with a conductive layer 34, and the lead portion 32 is covered with an insulating layer 33.

  The joining part 31 and the drawer | drawing-out part 32 are comprised by one member. For example, the joining part 31 and the drawer | drawing-out part 32 are comprised from one metal plate. The plate thickness of the joining portion 31 and the drawing portion 32 can be set to about 0.1 to 2.0 mm, for example.

  The joining part 31 and the drawer | drawing-out part 32 are comprised from the metal material. The joining part 31 and the drawer | drawing-out part 32 contain iron and chromium. Preferably, the joining part 31 and the drawer | drawing-out part 32 are comprised from stainless steel material. Specifically, the joining part 31 and the lead-out part 32 are made of ferritic stainless steel, austenitic stainless steel, or a Ni-based alloy.

[Joint part]
The joining portion 31 is configured to be joined to the fuel battery cell 1. Specifically, the joint portion 31 is joined to the fuel cell 1 via the conductive layer 34. The joining part 31 is plate-shaped. Specifically, the joint portion 31 has a rectangular shape when viewed in the arrangement direction (viewed in the z-axis direction). The width W1 of the joint portion 31 can be set to be approximately the same as the width of the lower power generation element portion 11a, for example.

As shown in FIG. 5, the joint portion 31 is joined to the lower power generation element portion 11a. Specifically, the joint portion 31 is joined to the electrical connection portion 111. For example, the joining portion 31 is joined to the lower power generation element portion 11 a by the first joining material 101. The first bonding material 101 is at least one selected from, for example, (Mn, Co) ₃ O ₄ , (La, Sr) MnO ₃ , and (La, Sr) (Co, Fe) O _3. .

[Drawer part]
As shown in FIG. 6, the drawer portion 32 extends from the joint portion 31. The lead-out part 32 extends in a direction (z-axis direction) orthogonal to the surface direction of the joint part 31 as a whole. Preferably, the drawer | drawing-out part 32 is extended from the lower end center part of the junction part 31, for example. The width W <b> 2 of the lead portion 32 is smaller than the width W <b> 1 of the joint portion 31. In addition, width W1, W2 of each part of the edge part current collection member 3 means the dimension in a 1st direction (y-axis direction).

  The drawer part 32 has a first part 321 and a second part 322. The first portion 321 extends in a direction along the surface direction of the joint portion 31. That is, the main surface of the first portion 321 and the main surface of the joint portion 31 are disposed on substantially the same surface. The first portion 321 extends from the joint portion 31 in the second direction (x-axis direction). The second direction is a direction orthogonal to the first direction in the same plane. In a state where the end current collecting member 3 is attached to the fuel cell 1, the first portion 321 extends downward from the joint portion 31.

  The second portion 322 is bent and extends from the first portion 321. That is, the second portion 322 extends from the lower end portion of the first portion 321. The second portion 322 extends along a direction (z-axis direction) orthogonal to the surface direction of the joint portion 31. That is, the second portion 322 extends in a direction orthogonal to the main surface of the joint portion 31.

  In a state where the end current collecting member 3 is attached to the fuel cell 1, the second portion 322 extends horizontally from the lower end portion of the first portion 321. Specifically, the second portion 322 extends in a direction away from the fuel cell 1.

  As shown in FIG. 5, the second portion 322 extends along the upper wall 22. The second portion 322 extends at a distance from the upper wall 22. In order to ensure insulation between the second portion 322 and the upper wall 22, an electrically insulating member may be disposed between the second portion 322 and the upper wall 22.

  As shown in FIG. 2, the leading end of the drawer portion 32 extends beyond the housing 90 to the outside of the housing 90. Specifically, the tip of the second portion 322 extends to the outside of the housing 90. The housing 90 has an extraction hole 91, and the drawer portion 32 extends to the outside of the housing 90 through the extraction hole 91. A lead wire of an external circuit or the like is attached to the leading end portion of the drawer portion 32. For example, an attachment hole or an attachment recess for attaching a lead wire is formed at the tip of the drawer portion 32.

[Insulation layer]
As shown in FIG. 7, the insulating layer 33 covers the lead portion 32. The insulating layer 33 can be made of an insulating material. For example, the insulating layer 33 can be made of insulating ceramics. More specifically, the insulating layer 33 can be made of alumina, silica, zirconia, magnesia, crystallized glass, or the like. The insulating layer 33 does not need to cover the entire surface of the drawer portion 32, and may cover at least a portion of the drawer portion 32 that may come into contact with the housing 90. In addition, the drawer portion 32 is connected to a lead wire or bus bar of an external circuit. The insulating layer 33 does not cover this connecting portion of the lead portion 32. The film thickness of the insulating layer 33 is, for example, about 1 to 200 μm. More preferably, the thickness of the insulating layer 33 can be 10 μm or more. The resistivity of the insulating layer 33 can be set to 1 to 600 MΩ · cm at 750 ° C., for example.

[Conductive layer]
The conductive layer 34 covers the joint portion 31. The conductive layer 34 preferably covers the entire joint portion 31. The conductive layer 34 can be made of a conductive material. For example, the conductive layer 34 can be composed of (Mn, Co) ₃ O ₄ , (La, Sr) MnO ₃ , (La, Sr) (Co, Fe) O _3, or the like. The conductive layer 34 is preferably a dense layer. For example, the porosity of the conductive layer 34 is about 10% or less. The film thickness of the conductive layer 34 is about 0.1 to 20 μm. The conductive layer 34 may cover the first portion 321 of the lead portion 32 instead of the insulating layer 33.

[Current collector between cells]
As shown in FIG. 2, each fuel cell 1 is electrically connected to each other via an inter-cell current collecting member 4. The inter-cell current collecting member 4 is disposed between the fuel cells 1 and electrically connects the adjacent fuel cells 1. The inter-cell current collecting member 4 is formed of a conductive material. For example, the inter-cell current collecting member 4 is formed of a sintered body of oxide ceramics or a metal. The inter-cell current collecting member 4 is joined to each fuel cell 1 by the second joining material 102. For example, the second bonding material 102 can be made of any of the materials mentioned as the material of the first bonding material 101.

[Front and back connection members]
In each fuel cell 1, the power generation element portion 11 formed on one surface of the support substrate 12 and the power generation element portion 11 formed on the other surface of the support substrate 12 are electrically connected by the front / back connection member 5. ing. Specifically, the front / back connection member 5 electrically connects the power generating element portions 11 disposed at the uppermost positions on one side and the other side of the support substrate 12.

[Third bonding material]
Each fuel cell 1 is fixed to the manifold 2 by a third bonding material 103. The third bonding material 103 joins the fuel battery cell 1 and the upper wall 22 of the manifold 2. The third bonding material 103 joins the lower end portion of the fuel battery cell 1 and the upper wall 22 of the manifold 2. As shown in FIG. 5, the third bonding material 103 is in contact with the dense film 18.

The third bonding material 103 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 may 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%. As the material of the third bonding material 103, amorphous glass, brazing material, ceramics, or the like may be employed. Specifically, the third bonding material 103 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. .

[Power generation method]
The cell stack device 100 configured as described above generates power as follows. By flowing a fuel gas (hydrogen gas or the like) through the manifold 2 into the gas flow path 121 of each fuel battery cell 1 and exposing both surfaces of the support substrate 12 to a gas (air or the like) containing oxygen, An electromotive force is generated by a difference in oxygen partial pressure generated between the two side surfaces. When this cell stack device 100 is connected to an external load using the end current collecting member 3, an electrochemical reaction shown in the following formula (1) occurs in the air electrode 15, and shown in the following formula (2) in the fuel electrode 13. An electrochemical reaction occurs and current flows.
(1/2) · O ₂ + 2e ⁻ → O ²⁻ (1)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (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 above embodiment, the fuel electrode current collector 131 has the second recess 131a and the third recess 131b, but the configuration of the fuel electrode current collector 131 is not limited to this. For example, the fuel electrode current collector 131 does not have to have recesses such as the second recess 131a and the third recess 131b. In this case, the anode active portion 132 is formed on the anode current collecting portion 131 and is not embedded in the anode current collecting portion 131. Further, the interconnector 112 and the first connection portion 113 are formed on the anode current collector 131 and are not embedded in the anode current collector 131.

Modification 2
In the said embodiment, although the 1st part 321 of the edge part current collection member 3 is extended in the direction along the surface direction of the junction part 31, the structure of the 1st part 321 is not limited to this. For example, as shown in FIG. 8, the surface direction of the first portion 321 may be inclined with respect to the surface direction of the joint portion 31. Specifically, the first portion 321 is inclined so as to move away from the fuel cell 1 as it goes downward. As shown in FIG. 9, the angle α formed by the main surface of the joint portion 31 and the main surface of the first portion 321 can be about 100 to 170 °.

Modification 3
As shown in FIG. 10, the drawer part 32 may have a drawer body part 323 and an intermediate part 324. The drawer main body 323 corresponds to the second portion 322 of the above embodiment, and the intermediate portion 324 corresponds to the first portion 321 of the above embodiment.

  The intermediate portion 324 is disposed between the drawer main body portion 323 and the joint portion 31. The intermediate portion 324 extends downward from the joint portion 31. The width W3 of the intermediate part 324 is smaller than the width W1 of the joint part 31 and larger than the width W4 of the drawer main body part 323. Note that the width W3 of the intermediate portion 324 decreases as the distance from the joint portion 31 increases. That the width W3 of the intermediate portion 324 is larger than the width W4 of the drawer main body portion 323 means that the width W3 at the upper end portion of the intermediate portion 324 is larger than the width W3 of the drawer main body portion 323. The width W4 of the drawer body 323 is smaller than the width W1 of the joint 31.

  Note that the width W <b> 3 of the intermediate portion 324 does not have to decrease as the distance from the joint portion 31 increases. For example, as shown in FIG. 11, the width W3 of the intermediate portion 324 may be constant.

Modification 4
In the said embodiment, although the drawer | drawing-out part 32 had the 1st part 321 and the 2nd part 322, the structure of the drawer | drawing-out part 32 is not limited to this. For example, as shown in FIG. 12, the drawer portion 32 may not have the first portion 321. In this case, the second portion 322 extends directly from the joint portion 31.

Modification 5
In the said embodiment, although the edge part current collection member 3 is joined to the electrical connection part 111 of the lower power generation element part 11a, it is not limited to this in particular. For example, as shown in FIG. 13, the end current collecting member 3 may be joined to the power generation element main body 110 of the lower power generation element portion 11a. In this case, the lower power generation element portion 11a may not have the electrical connection portion 111.

Modification 6
In the said embodiment, although the edge part current collection member 3 is joined to the lower power generation element part 11a, you may be joined to power generation element parts 11 other than the lower power generation element part 11a.

Modification 7
In the said embodiment, although the 2nd part 322 is extended substantially parallel to the upper surface of a manifold, it is not limited to this in particular. For example, as shown in FIG. 14, the second portion 322 may be inclined and extended away from the upper surface of the upper wall 22 of the manifold as it is away from the first portion 321. Further, as shown in FIG. 15, the second portion 322 may be inclined and extended so as to approach the upper surface of the upper wall 22 of the manifold 2 as the distance from the first portion 321 increases. At this time, the angle θ of the second portion 322 with respect to the upper surface of the upper wall 22 of the manifold 2 is not particularly limited, but may be, for example, about 0.5 to 20 degrees.

Modification 8
As shown in FIG. 16, the joining part 31 and the drawer | drawing-out part 32 may have the oxide film 300 on the surface. In this case, the insulating layer 33 and the conductive layer 34 cover the lead portion 32 and the joint portion 31 from above the oxide film 300. Note that the conductive layer 34 may not be formed.

  The oxide film 300 of the lead portion 32 is thinner than the oxide film 300 of the joint portion 31. Specifically, the thickness of the oxide film 300 of the joint portion 31 is, for example, about 0.5 to 40 μm, and the thickness of the oxide film 300 of the lead portion 32 is, for example, about 0.1 to 20 μm. . Note that the oxide film 300 may or may not be provided on the surface of the bonding portion 31 that is in contact with the first bonding material 101.

  The thickness of the oxide film 300 of the joint portion 31 can be measured, for example, by cutting the central portion of the joint portion 31 along a plane orthogonal to the joint portion 31. Moreover, the thickness of the oxide film 300 of the drawer | drawing-out part 32 can be cut | disconnected by the surface orthogonal to the 2nd part 322 in the arbitrary positions of the 2nd part 322, and can be measured in the cut surface.

  In this modification, the joining part 31 and the drawer | drawing-out part 32 are comprised by the alloy etc. which contain Cr (chromium), for example. As such an alloy, Fe—Cr alloy steel (stainless steel, etc.), Ni—Cr alloy steel, or the like can be used. Moreover, as the oxide film 300 described above, a chromium oxide film or the like can be exemplified. By heat-treating the drawing portion 32 at a lower temperature than the bonding portion 31, the oxide film 300 of the drawing portion 32 can be made thinner than the oxide film 300 of the bonding portion 31.

Modification 9
In the said embodiment, although the junction part 31 of the edge part current collection member 3 is extended substantially parallel to the outer surface S of the lower side power generation element part 11a, it is not limited to this, It is set as the following structures. Can do.

  As shown in FIG. 17, the joining portion 31 of the end current collecting member 3 is joined to the outer surface S of the lower power generation element portion 11 a via the first joining material 101. The junction 31 has a chromium oxide film 301Y on the surface. Specifically, the joint portion 31 includes a base material 301X and a chromium oxide film 301Y.

  The substrate 301X is formed in a plate shape. The thickness of the base material 301X is not particularly limited, but can be, for example, 0.1 to 4.0 mm.

  The substrate 301X is made of an alloy containing Cr (chromium). As such an alloy, Fe—Cr alloy steel (stainless steel, etc.), Ni—Cr alloy steel, or the like can be used. Although the content rate of Cr in the base material 301X is not particularly limited, it can be, for example, 4 to 30% by mass.

The base material 301X may contain Ti (titanium) or Al (aluminum). The content ratio of Ti in the base material 301X is not particularly limited, but is 0.01 to 1.0 at. %. Although the content rate of Al in the base material 301X is not particularly limited, for example, 0.01 to 0.4 at. %. The base material 301X may contain Ti as TiO ₂ (titania) or may contain Al as Al ₂ O ₃ (alumina).

  The chromium oxide film 301Y is formed on the base material 301X. The chromium oxide film 301Y covers the base material 301X. The chromium oxide film 301Y preferably covers the entire surface of the substrate 301X, but may not partially cover the surface of the substrate 301X. The thickness of the chromium oxide film 301Y is not particularly limited, but can be, for example, 1 μm to 20 μm.

The chromium oxide film 301Y contains chromium oxide (Cr ₂ O ₃ ) as a main component. Specifically, the chromium oxide film 301Y contains 50 wt% or more of chromium oxide. The chromium oxide film 301Y may contain Mn, Fe, Cr, Mo, Si, or the like as impurities. The chromium oxide film 301Y can be formed by depositing an oxide by reacting with a reactive gas (for example, oxygen) by sputtering an Cr target using an RF (radio-frequency) magnetron sputtering apparatus.

  As shown in FIG. 17, the base material 301X includes a first surface Y1, a second surface Y2, and a corner portion Y3 in a cross section perpendicular to the outer surface S of the lower power generation element portion 11a.

  The first surface Y1 has an angle with respect to the outer surface S of the lower power generation element portion 11a. That is, the first surface Y1 is not parallel to the outer surface S but is inclined with respect to the outer surface S. The first surface Y1 is closer to the outer surface S toward the corner Y3. The angle θ1 of the first surface Y1 with respect to the outer surface S is not particularly limited, but can be, for example, 0.5 degrees to 45 degrees. In the example shown in FIG. 17, the first surface Y1 is formed flat, but in actuality, minute unevenness may be formed.

  In the first surface Y1, the chromium oxide film 301Y preferably covers the base member 301X. The thickness of the chromium oxide film 301 </ b> Y formed on the first surface Y <b> 1 may be formed thicker as it approaches the corner Y <b> 3.

  The second surface Y2 is continuous with the first surface Y1. The second surface Y2 has an angle with respect to the outer surface S of the lower power generation element portion 11a. That is, the second surface Y2 is not parallel to the outer surface S but is inclined with respect to the outer surface S. The second surface Y2 approaches the outer surface S toward the corner Y3 side. The angle θ2 of the second surface Y2 with respect to the outer surface S is not particularly limited, but can be, for example, 45 degrees to 135 degrees.

  The second surface Y2 has an angle with respect to the first surface Y1. That is, the second surface Y2 is not parallel to the first surface Y1, but is inclined with respect to the first surface Y1. The angle θ3 of the second surface Y2 with respect to the first surface Y1 is not particularly limited, but can be, for example, 30 degrees to 135 degrees. In the example shown in FIG. 17, the second surface Y2 is formed flat. However, actually, minute unevenness may be formed.

  In the second surface Y2, the chromium oxide film 301Y preferably covers the base material 301X. The thickness of the chromium oxide film 301Y formed on the second surface Y2 may be formed thicker as it approaches the corner Y3.

  The corner Y3 is formed by the first surface Y1 and the second surface Y2. In the present embodiment, “formed by the first surface Y1 and the second surface Y2” means “defined by the first surface Y1 and the second surface Y2”, “the first surface Y1 and the second surface. It means at least one of “partitioned by Y2” and “provided between the first surface Y1 and the second surface Y2.”

  The corner portion Y3 may be formed such that the first surface Y1 and the second surface Y2 are bent so that the first surface Y1 and the second surface Y2 are one or more other surfaces (curved). (A surface or a bent surface).

  In the corner portion Y3, the chromium oxide film 301Y preferably covers the base member 301X. The chromium oxide film 301Y formed at the corner portion Y3 may be formed thicker than the other portions around the corner portion Y3.

  The corner portion Y3 is closer to the outer surface S of the lower power generation element portion 11a than the first surface Y1 and the second surface Y2. The corner portion Y <b> 3 is provided at the first tip portion 301 a of the end current collecting member 3. In the present modification, the corner Y3 is a portion of the end current collecting member 3 that is closest to the outer surface S of the lower power generation element portion 11a. The distance D from the corner Y3 to the outer surface S is not particularly limited, but can be 0.5 to 2000 μm.

  The current flowing from the lower power generating element portion 11a to the end current collecting member 3 is concentrated on the corner Y3 of the end current collecting member 3 that is close to the outer surface S of the lower power generating element portion 11a. When the current concentrates on the corner Y3, the temperature of the corner Y3 increases, so the temperature of the chromium oxide film 301Y formed in the corner Y3 increases, and the electrical resistance of the chromium oxide film 301Y decreases. As a result, since a current can flow smoothly from the lower power generating element portion 11a to the end current collecting member 3, the electrical connectivity between the lower power generating element portion 11a and the end current collecting member 3 can be improved. Can do.

  Further, since each of the first surface Y1 and the second surface Y2 forming the corner portion Y3 has an angle with respect to the outer surface S, when the corner portion Y3 is inserted into the first conductive bonding material 102a. In addition, bubbles in the first conductive bonding material 102a can be excluded from the periphery of the corner Y3. As a result, the electrical connectivity between the lower power generation element portion 11a and the end current collecting member 3 can be further improved.

  The end current collecting member 3 according to this modification does not have the conductive layer 34, but may have the conductive layer 34. In this case, the conductive layer 34 can be configured to cover the bonding portion 31 from above the chromium oxide film 301Y.

  The present invention will be described more specifically with reference to the following examples and comparative examples. In addition, this invention is not limited to the following Example.

  A plurality of end current collecting members 3 having a shape as shown in FIG. 6 were produced. In detail, the metal plate was pressed and the insulating layer 33 was formed so that the drawer | drawing-out part 32 might be covered. The insulating layer 33 was formed on the extraction portion 32 by dip coating or thermal spraying. The insulating layer 33 is changed in material and thickness for each sample. The material, thickness, and resistivity of the insulating layer 33 are as shown in Table 1. In addition, the insulating layer 33 and the conductive layer 34 are not formed in the bonding portion 31. Sample 21 is a comparative example, and the insulating layer 33 is not formed on the lead portion 32. The resistivity of each material was measured with reference to the direct current three-terminal method (JIS C2141). An insulating layer 33 was formed on a metal plate simulating the end current collecting member 3, and a main electrode and a guard electrode were formed on the insulating layer side, and a counter electrode was formed on the metal plate side with platinum. About the produced sample, volume resistivity was measured at 750 degreeC in air | atmosphere, and what removed the resistance of the metal plate was made into the resistivity of each material.

  The end current collecting member 3 produced in this way was joined to the power generation element part 11 of the fuel cell 1 via the first joining material 101. In this state, the distance between the insulating layer 33 covering the lead-out portion 32 of the end current collecting member 3 and the upper wall 22 of the manifold 2 was about 10 mm.

(Evaluation method)
Each sample produced as described above was evaluated for the possibility of short circuit prevention with the casing of the insulating layer 33. Specifically, an electronic load device is connected to each lead-out portion 32 of the end current collecting member 3 joined to the power generation element portion 11 on both surfaces of the fuel cell 1 via a lead wire so that power generation can be evaluated. . Further, a U-shaped metal piece simulating the casing was brought into contact with the drawer portion 32, and the energization test of the fuel cell was performed by simulating the state where the casing was in contact. Specifically, an alumina block having a height of 10 mm is placed on the upper wall 22 of the manifold 2, and a U-shaped metal piece is placed on the block and brought into contact with the drawer portion 32. went. This energization test was performed with 5 samples per level. In Table 1, among the five samples, the ones that could carry out the energization test without any defects were evaluated as “◎”. In addition, even in one of the five samples, a case where a short circuit was formed between the lead portion 32 and the metal piece to generate a large current and evaluation was impossible was evaluated as “good”. On the other hand, when the evaluation was impossible with all five, “x” was given as no short-circuit prevention effect. Table 1 shows the numbers that could not be evaluated at each level.

  As shown in Table 1, it was found that the one that formed the insulating layer 33 had a short-circuit preventing effect compared to the one that did not form the insulating layer 33. Further, it has been found that the short circuit between the lead portion 32 and the housing can be more reliably prevented by setting the resistivity of the insulating layer 33 to 1 MΩ or more and the film thickness to 10 μm or more.

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Manifold 3 End current collection member 31 Junction part 32 Drawer part 33 Insulation layer 34 Conductive layer 90 Case 91 Extraction hole 100 Cell stack apparatus

Claims (10)

A housing having an extraction hole;
A manifold disposed within the housing;
A fuel cell disposed within the housing and extending upward from the manifold;
And the end portion current collector that will be connected the fuel cells electrically,
With
The end current collecting member is
A joint configured to be joined to the fuel cell;
A drawer extending from the joint;
An insulating layer covering the lead portion;
Have
The lead-out portion of the end current collecting member extends to the outside of the casing through the extraction hole of the casing.
Cell stack device.
  The end current collecting member further includes a conductive layer covering the joining portion.
The cell stack device according to claim 1.
  The insulating layer is made of insulating ceramics.
The cell stack apparatus according to claim 1 or 2.
  The joint is made of a metal material containing iron and chromium.
The cell stack device according to claim 1.
  The joint portion and the drawer portion are configured by one member.
The cell stack device according to claim 1.
  The joint part and the drawer part are composed of a single metal plate,
The cell stack device according to claim 1.
The drawer has a second portion extending along an upper surface of the manifold;
The second portion extends obliquely away from the top surface of the manifold as it moves away from the joint.
The cell stack device according to claim 1 .
The drawer has a second portion extending along an upper surface of the manifold;
The second portion extends at an angle so as to approach the upper surface of the manifold as it moves away from the joint.
The cell stack device according to claim 1 .
The joint and the drawer have an oxide film on the surface,
The oxide film of the drawer part is thinner than the oxide film of the joint part,
The cell stack device according to claim 1 .
A first bonding material for bonding the fuel cell and the bonding portion;
The joint has a base material made of an alloy containing Cr, and a chromium oxide film covering the base material,
In a cross section perpendicular to the outer surface of the fuel cell, the joint includes a first surface having an angle with respect to the outer surface, a second surface having an angle with respect to the outer surface, and the first surface. And a corner formed by the second surface,
The corner is closer to the outer surface than each of the first surface and the second surface;
The cell stack device according to claim 1 .

Images