JP6578415B1 - Metal member for electrochemical cell, cell stack and cell stack apparatus - Google Patents

Abstract

An object of the present invention is to provide a metal member for an electrochemical cell, a cell stack, and a cell stack device capable of suppressing peeling of a coating film. A current collecting member includes a base material made of an alloy material containing chromium and a coating film that covers the base material. The base material 302 has a base material main body 302a having a first surface S1 and a first arm part 302b extending from the base material main body 302a. The first arm portion 302b faces the first surface S1 in a cross section perpendicular to the first surface S1. [Selection] Figure 10

Description

  The present invention relates to a metal member for an electrochemical cell, a cell stack, and a cell stack apparatus.

  2. Description of the Related Art Conventionally, a cell stack device is known that includes a cell stack in which a plurality of fuel cells are electrically connected by a current collecting member, and a manifold that supports each fuel cell (see Patent Documents 1 and 2). . A metal member is used for the current collecting member and the manifold.

  In Patent Document 1, in order to suppress the volatilization of Cr (chromium) from a base material composed of stainless steel, a metal member having a coating film covering the surface of the base material is used as a current collecting member. .

  In Patent Document 2, a metal member having a coating film that covers the surface of the base material is used as a manifold in order to suppress the volatilization of Cr from the base material made of stainless steel.

International Publication No. 2013/172451 Japanese Patent Laying-Open No. 2015-035418

  However, in the metal members described in Patent Documents 1 and 2, when the operation / non-operation of the cell stack device is repeated, the coating film may be stressed and peeled from the substrate.

  The present invention has been made in view of the above-described situation, and an object thereof is to provide a metal member for an electrochemical cell, a cell stack, and a cell stack device that can suppress peeling of a coating film.

  The metal member for an electrochemical cell according to the present invention includes a base material composed of an alloy material containing chromium and a coating film that covers the base material. The base material has a base material body portion having a first surface and a first arm portion extending from the base material body portion. The first arm portion faces the first surface in a cross section perpendicular to the first surface.

  ADVANTAGE OF THE INVENTION According to this invention, the metal member for electrochemical cells which can suppress peeling of a coating film, a cell stack, and a cell stack apparatus can be provided.

The perspective view of a cell stack apparatus. Sectional drawing of a cell stack apparatus. The perspective view of a fuel manifold. The perspective view of a fuel cell. Sectional drawing of a fuel cell. The elements on larger scale of FIG. The perspective view of a current collection member. AA sectional drawing of FIG. The enlarged view of area | region R1 of FIG. The enlarged view of area | region R2 of FIG.

  Hereinafter, an embodiment of a cell stack device using a current collecting member according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of the cell stack apparatus 100. FIG. 2 is a cross-sectional view of the cell stack apparatus 100.

  As shown in FIGS. 1 and 2, the cell stack device 100 includes a fuel manifold 200 and a plurality of fuel cells 300 (an example of an “electrochemical cell”).

[Fuel manifold]
FIG. 3 is a perspective view of the fuel manifold 200.

  As shown in FIG. 3, the fuel manifold 200 is configured to distribute fuel gas (for example, hydrogen) to each fuel cell 300. The fuel manifold 200 is hollow and has an internal space. Fuel gas is supplied to the internal space of the fuel manifold 200 through the introduction pipe 201. The fuel manifold 200 has a plurality of insertion holes 202 arranged at intervals. Each insertion hole 202 is formed in the top plate 203 of the fuel manifold 200. Each insertion hole 202 communicates with the internal space of the fuel manifold 200 and the outside.

[Fuel battery cell]
As shown in FIG. 2, each fuel cell 300 extends from the fuel manifold 200. Specifically, each fuel cell 300 extends upward (x-axis direction) from the top plate 203 of the fuel manifold 200. That is, the longitudinal direction (x-axis direction) of each fuel cell 300 extends upward. The length of each fuel cell 300 in the longitudinal direction (x-axis direction) can be about 100 to 300 mm.

The base end portion of each fuel cell 300 is inserted into the insertion hole 202 of the fuel manifold 200. Each fuel cell 300 is fixed to the insertion hole 202 by a bonding material 101. The fuel battery cell 300 is fixed to the fuel manifold 200 by the bonding material 101 in a state of being inserted into the insertion hole 202. The bonding material 101 is filled in a gap between the fuel battery cell 300 and the insertion hole 202. Examples of the bonding material 101 include crystallized glass, amorphous glass, brazing material, and ceramics. With crystallized glass, the ratio of “volume occupied by crystal phase” to the total volume (crystallinity) is 60% or more, and the ratio of “volume occupied by amorphous phase and impurities” to the total volume is less than 40%. Glass. Examples of such crystallized glass include SiO ₂ —B ₂ O ₃ system, SiO ₂ —CaO system, and SiO ₂ —MgO system.

  Each fuel cell 300 is formed in a plate shape extending in the longitudinal direction (x-axis direction) and the width direction (y-axis direction). The fuel cells 300 are arranged at intervals in the arrangement direction (z-axis direction). The interval between two adjacent fuel cells 300 is not particularly limited, but can be about 1 to 5 mm. Two adjacent fuel cells 300 are electrically connected by a current collecting member 301. A plurality of fuel cells 300 are connected by a current collecting member 301 to form a cell stack. The configuration of the current collecting member 301 will be described later.

  The fuel cell 300 includes a plurality of power generation element units 10 and a support substrate 20.

[Support substrate]
FIG. 4 is a perspective view of the fuel battery cell 300. FIG. 5 is a cross-sectional view of the fuel battery cell 300.

  As shown in FIG. 4, the support substrate 20 has a plurality of gas passages 21 extending along the longitudinal direction (x-axis direction) of the support substrate 20. Each gas flow path 21 extends from the proximal end side of the support substrate 20 toward the distal end side. Each gas channel 21 extends substantially parallel to each other. The base end side means the gas supply side of the gas flow path. Specifically, when the fuel battery cell 300 is attached to the fuel manifold 200, the side close to the fuel manifold 200 is meant. Further, the tip side means the side opposite to the gas supply side of the gas flow path. Specifically, when the fuel cell 300 is attached to the fuel manifold 200, it means the side far from the fuel manifold 200. For example, in the example shown in FIG. 2, the lower side is the proximal end side, and the upper side is the distal end side.

  As shown in FIG. 5, the support substrate 20 has a plurality of first recesses 22. In the present embodiment, each first recess 22 is formed on both main surfaces of the support substrate 20, but may be formed only on one main surface. The first recesses 22 are arranged at intervals in the longitudinal direction of the support substrate 20.

The support substrate 20 is made of a porous material that does not have electronic conductivity. The support substrate 20 can be made of, for example, CSZ (calcia stabilized zirconia). Alternatively, the support substrate 20 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 20 is, for example, about 20 to 60%.

[Power generation element]
Each power generation element unit 10 is supported by a support substrate 20. In the present embodiment, each power generating element unit 10 is formed on both main surfaces of the support substrate 20, but may be formed only on one main surface. The power generation element units 10 are arranged at intervals in the longitudinal direction of the support substrate 20. That is, the fuel cell 300 according to the present embodiment is a so-called horizontal stripe fuel cell. The power generating element portions 10 adjacent in the longitudinal direction are electrically connected to each other by an interconnector 31.

  The power generation element unit 10 includes a fuel electrode 4, an electrolyte 5, and an air electrode 6. In addition, the power generation element unit 10 further includes a reaction preventing film 7.

[Fuel electrode]
The fuel electrode 4 is a fired body made of a porous material having electron conductivity. The fuel electrode 4 includes a fuel electrode current collector 41 and a fuel electrode active part 42.

  The fuel electrode current collector 41 is disposed in the first recess 22. Specifically, the fuel electrode current collector 41 is filled in the first recess 22 and has the same outer shape as the first recess 22. The fuel electrode current collector 41 has a second recess 411 and a third recess 412. A fuel electrode active portion 42 is disposed in the second recess 411. Further, the interconnector 31 is disposed in the third recess 412.

  The fuel electrode current collector 41 has electronic conductivity. The fuel electrode current collector 41 preferably has higher electron conductivity than the fuel electrode active part 42. The fuel electrode current collector 41 may or may not have oxygen ion conductivity.

The fuel electrode current collector 41 can be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode current collector 41 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 41 and the depth of the first recess 22 are about 50 to 500 μm.

  The fuel electrode active portion 42 has oxygen ion conductivity and electronic conductivity. The anode active part 42 has a higher content of oxygen ion conductive material than the anode current collector 41. Specifically, the volume ratio of the substance having oxygen ion conductivity with respect to the total volume excluding the pore portion in the fuel electrode active portion 42 is determined by the oxygen ion conduction in the total volume excluding the pore portion in the fuel electrode current collector 41. It is larger than the volume ratio of the substance having the property.

  The fuel electrode active part 42 may be composed of, for example, NiO (nickel oxide) and YSZ (8YSZ) (yttria stabilized zirconia). Alternatively, the fuel electrode active part 42 may be composed of NiO (nickel oxide) and GDC (gadolinium-doped ceria). The thickness of the fuel electrode active part 42 is 5 to 30 μm.

[Electrolytes]
The electrolyte 5 is disposed so as to cover the fuel electrode 4. Specifically, the electrolyte 5 extends in the longitudinal direction from one interconnector 31 to the adjacent interconnector 31. That is, the electrolyte 5 and the interconnector 31 are alternately and continuously arranged in the longitudinal direction (x-axis direction) of the support substrate 20. The electrolyte 5 is configured to cover the first main surface 23 a and the second main surface 23 b of the support substrate 20.

  The electrolyte 5 is a fired body made of a dense material that has ionic conductivity and no electronic conductivity. The electrolyte 5 can be made of, for example, YSZ (8YSZ) (yttria stabilized zirconia). Or the electrolyte 5 may be comprised from LSGM (lanthanum gallate). The thickness of the electrolyte 5 is, for example, about 3 to 50 μm.

[Reaction prevention film]
The reaction preventing film 7 is a fired body composed of a dense material. The reaction preventing film 7 is disposed between the electrolyte 5 and the air electrode active part 61. The reaction preventing film 7 suppresses occurrence of a phenomenon in which YSZ in the electrolyte 5 and Sr in the air electrode 6 react to form a reaction layer having a large electric resistance at the interface between the electrolyte 5 and the air electrode 6. Is provided.

The reaction preventing film 7 is made of a material containing ceria containing a rare earth element. The reaction preventing film 7 can be made of, for example, GDC = (Ce, Gd) O ₂ (gadolinium-doped ceria). The thickness of the reaction preventing film 7 is, for example, about 3 to 50 μm.

[Air electrode]
The air electrode 6 is a fired body composed of a porous material having electron conductivity. The air electrode 6 is disposed on the opposite side of the fuel electrode 4 with respect to the electrolyte 5. The air electrode 6 includes an air electrode active part 61 and an air electrode current collector 62.

  The air electrode active part 61 is disposed on the reaction preventing film 7. The air electrode active part 61 has oxygen ion conductivity and electron conductivity. The air electrode active part 61 has a higher content of a substance having oxygen ion conductivity than the air electrode current collecting part 62. Specifically, the volume ratio of the substance having oxygen ion conductivity with respect to the total volume excluding the pore portion in the air electrode active portion 61 is determined by the oxygen ion conductivity in the air electrode current collector 62 with respect to the total volume excluding the pore portion. It is larger than the volume ratio of the substance having the property.

The air electrode active part 61 can be composed of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode active part 61 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 61 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 61 is, for example, 10 to 100 μm.

  The air electrode current collector 62 is disposed on the air electrode active part 61. The air electrode current collector 62 extends from the air electrode active part 61 toward the adjacent power generation element part. The fuel electrode current collector 41 and the air electrode current collector 62 extend from the power generation region to opposite sides. The power generation region is a region where the fuel electrode active part 42, the electrolyte 5, and the air electrode active part 61 overlap.

  The air electrode current collector 62 is a fired body made of a porous material having electronic conductivity. The air electrode current collector 62 preferably has higher electron conductivity than the air electrode active part 61. The air electrode current collector 62 may or may not have oxygen ion conductivity.

The air electrode current collector 62 can be made of, for example, LSCF = (La, Sr) (Co, Fe) O ₃ (lanthanum strontium cobalt ferrite). Alternatively, the air electrode current collector 62 may be made of LSC = (La, Sr) CoO ₃ (lanthanum strontium cobaltite). Or the air electrode current collection part 62 may be comprised from Ag (silver) and Ag-Pd (silver palladium alloy). The thickness of the air electrode current collector 62 is, for example, about 50 to 500 μm.

[Interconnector]
The interconnector 31 is configured to electrically connect the power generating element portions 10 adjacent in the longitudinal direction (x-axis direction) of the support substrate 20. Specifically, the air electrode current collector 62 of one power generation element unit 10 extends toward the other power generation element unit 10. Further, the fuel electrode current collector 41 of the other power generating element unit 10 extends toward the one power generating element unit 10. The interconnector 31 electrically connects the air electrode current collector 62 of one power generating element unit 10 and the fuel electrode current collector 41 of the other power generating element unit 10. The interconnector 31 is disposed in the third recess 412 of the fuel electrode current collector 41. Specifically, the interconnector 31 is embedded in the third recess 412.

The interconnector 31 is a fired body composed of a dense material having electronic conductivity. The interconnector 31 can be made of, for example, LaCrO ₃ (lanthanum chromite). Alternatively, the interconnector 31 may be made of (Sr, La) TiO ₃ (strontium titanate). The thickness of the interconnector 31 is, for example, 10 to 100 μm.

[Current collecting member]
FIG. 6 is a partially enlarged view of FIG. FIG. 6 shows the vicinity of the base end portion of each fuel cell 300 in the cell stack apparatus 100.

  As shown in FIG. 6, two adjacent fuel cells 300 (first fuel cell 300 a and second fuel cell 300 b) are electrically connected by a current collecting member 301. The current collecting member 301 is an example of a metal member for an electrochemical cell.

  The current collecting member 301 is disposed between the first fuel cell 300a and the second fuel cell 300b. The current collecting member 301 is arranged closer to the base end side than the base end side power generating element part 10a arranged closest to the base end side among the plurality of power generating element parts 10 arranged on both main surfaces of the support substrate 20. Yes.

  The current collecting member 301 is joined to the base end sides of the first fuel cell 300a and the second fuel cell 300b. Specifically, the current collecting member 301 includes the electrical connection part 110 extending from the base-end power generation element part 10a of the first fuel cell 300a and the base of the second fuel battery cell 300b via the conductive bonding material 102. It is joined to the air electrode current collector 62 extending from the end-side power generating element portion 10a.

As the conductive bonding material 102, known conductive ceramics or the like can be used. For example, the conductive bonding material 102 is composed of at least one selected from (Mn, Co) ₃ O ₄ , (La, Sr) MnO ₃ , and (La, Sr) (Co, Fe) O _3. Can do.

  Here, FIG. 7 is a perspective view of the current collecting member 301, and FIG. 8 is a cross-sectional view taken along the line AA of FIG. FIG. 7 shows a state where the current collecting member 301 is joined to the first fuel cell 300a. In FIG. 7, the second fuel battery cell 300b is omitted, but actually, the second fuel battery cell 300b is arranged so as to face the first fuel battery cell 300a.

  The current collecting member 301 includes a first joint part a1, a second joint part a2, a first connection part b1, and a second connection part b2.

  The first joint part a1 is joined to the first fuel cell 300a. Specifically, the first joint portion a1 is joined to the electrical connection portion 110 that extends from the base-end-side power generation element portion 10a (see FIG. 6) of the first fuel cell 300a by the conductive joint material 102. The electrical connection unit 110 includes a first connection unit 111 and a second connection unit 112. The 1st connection part 111 can be set as the structure and material similar to the interconnector 31 mentioned above. The second connection portion 112 can be made of the same material as the air electrode current collector 62 described above. The second connection portion 112 is electrically connected to the first connection portion 111 and extends downward. As shown in FIG. 8, the first joint a1 has a main surface Sa that faces the outer surface Ta of the first fuel cell 300a.

  The 1st junction part a1 is formed in flat form. Although the thickness in particular of 1st junction part a1 in az axis direction is not restrict | limited, For example, it can be set as 0.1-2.0 mm. In the present embodiment, the first joint portion a1 is formed in a rectangular shape extending in the width direction, but the shape of the first joint portion a1 is not particularly limited, and is a triangle or more polygon, a circle, an ellipse, or Other complicated shapes may be used.

  A plurality of first through holes c1 are formed in the first joint portion a1. As shown in FIG. 8, each first through hole c <b> 1 has an inner wall surface Sc that is continuous with the main surface Sa. Each first through-hole c1 is filled with the conductive bonding material 102. Thereby, the joining force of the 1st junction part a1 with respect to the 1st fuel cell 300a can be improved. The conductive bonding material 102 may protrude outward from each first through hole c1, and may further spread on the outer surface of the first bonding portion a1.

  In the present embodiment, each first through-hole c1 is formed in a rectangular shape extending along the width direction, but the shape of each first through-hole c1 is not particularly limited, and is more than a circle, an ellipse, a triangle or more It may be a polygon or a complex shape other than these. In the present embodiment, three first through holes c1 are provided, but the number and position of the first through holes c1 can be changed as appropriate.

  The second joint a2 is electrically connected to the first joint a1. The second joint portion a2 is joined to the second fuel cell 300b. Specifically, the second joint portion a2 is joined to the air electrode current collector 62 extending from the base-end-side power generation element portion 10a (see FIG. 6) of the second fuel cell 300b by the conductive joint material 102. The second joint part a2 faces the first joint part a1 in the arrangement direction.

  The 2nd junction part a2 is formed in flat form. Although the thickness in particular of 2nd junction part a2 in az axis direction is not restrict | limited, For example, it can be set as 0.1-2.0 mm. In the present embodiment, the second joint part a2 has the same shape as the first joint part a1, but may have a different shape from the first joint part a1. There is no restriction | limiting in particular in the shape of 2nd junction part a2, Polygon more than a triangle, circular, an ellipse, or complicated shapes other than these may be sufficient.

  A plurality of second through holes c2 are formed in the second joint portion a2. Each second through-hole c2 is filled with the conductive bonding material 102. Thereby, the joining force of the 2nd junction part a2 with respect to the 2nd fuel cell 300b can be improved. The conductive bonding material 102 may protrude outward from each second through hole c2, and may further spread on the outer surface of the second bonding portion a2.

  In the present embodiment, each second through hole c2 is formed in a rectangular shape extending along the width direction, but the shape of each second through hole c2 is not particularly limited, and may be a circle, an ellipse, or a triangle or more. It may be a polygon or a complex shape other than these. In the present embodiment, three second through holes c2 are provided, but the number and position of the second through holes c2 can be changed as appropriate.

  The first and second connection parts b1 and b2 are connected to the first joint part a1 and the second joint part a2, respectively. In the present embodiment, the first and second connecting portions b1 and b2 are curved, but are not limited thereto. Each of the first and second connecting portions b1 and b2 may have a flat plate shape or a shape that bends at least at one place.

  In the present embodiment, the first and second connecting portions b1 and b2 are disposed at both ends of the current collecting member 301, but the positions of the first and second connecting portions b1 and b2 are not particularly limited.

[Internal structure of current collector]
Next, a detailed configuration of the current collecting member 301 will be described with reference to the drawings. FIG. 9 is an enlarged view of a region R1 in FIG.

  The current collecting member 301 includes a base material 302, a chromium oxide film 303, and a coating film 304.

  The base material 302 is made of an alloy material containing Cr (chromium). As such a metal material, Fe—Cr alloy steel (such as stainless steel) and Ni—Cr alloy steel can be used. Although the content rate of Cr in the base material 302 is not particularly limited, it can be 4 to 30% by mass.

The base material 302 may contain Ti (titanium) or Al (aluminum). The Ti content in the substrate 302 is not particularly limited, but is 0.01 to 1.0 at. %. The Al content in the substrate 302 is not particularly limited, but is 0.01 to 0.4 at. %. The base material 302 may contain Ti as TiO ₂ (titania) or may contain Al as Al ₂ O ₃ (alumina).

  The chromium oxide film 303 is formed on the base material 302. The chromium oxide film 303 covers the base material 302. The chromium oxide film 303 may cover a part of the substrate 302 or may cover the entire substrate 302.

  The chromium oxide film 303 is composed of chromium oxide. The thickness of the chromium oxide film 303 is not particularly limited, but can be, for example, 0.5 to 10 μm.

  The covering film 304 is formed on the chromium oxide film 303. The coating film 304 covers the substrate 302. Specifically, the coating film 304 covers the chromium oxide film 303 formed on the base material 302. The coating film 304 may cover a part of the substrate 302 or may cover the entire substrate 302. The coating film 304 preferably covers a region of the substrate 302 that comes into contact with the oxidant gas during the operation of the cell stack apparatus 100.

  The coating film 304 suppresses Cr poisoning in the air electrode 6 of each fuel cell 300 by suppressing the volatilization of Cr from the base material 302. As a material constituting the coating film 304, a ceramic material can be used. The specific type of the ceramic material can be appropriately selected according to the application location. In the present embodiment, since the current collecting member 301 is required to have conductivity, the ceramic material is composed of a perovskite complex oxide containing La and Sr, and a transition metal such as Mn, Co, Ni, Fe, and Cu. Spinel type complex oxide can be used. However, the coating film 304 only needs to be able to suppress the volatilization of Cr, and its constituent material is not limited to a ceramic material. The thickness of the coating film 304 is not particularly limited, but can be, for example, 1 to 200 μm.

[Structure of substrate]
Next, the structure of the base material 302 in the current collecting member 301 will be described with reference to the drawings. FIG. 10 is an enlarged view of a region R2 in FIG.

  The base material 302 has a base material main body 302a, a first arm 302b, and a second arm 302c.

  The base material main body 302 a is a main body that occupies most of the base material 302. The base body 302a has a first surface S1. The first surface S1 is an outer surface of the base body main body 302a. As shown in FIG. 10, the area | region which opposes the 1st arm part 302b among 1st surface S1 is formed diagonally toward the inner side of the base-material main-body part 302a. Similarly, the area | region which opposes the 2nd arm part 302c among 1st surface S1 is formed diagonally toward the inner side of the base-material main-body part 302a. In addition, between the region (upper side in FIG. 10) of the first surface S1 connected to the second arm 302c and the region (lower side of FIG. 10) of the first surface S1 connected to the first arm 302b. , A step is formed.

  The first arm part 302b is connected to the base body part 302a. The first arm portion 302b is formed integrally with the base material main body portion 302a. The 1st arm part 302b is extended from the base-material main-body part 302a. The proximal end portion of the first arm portion 302b is a fixed end, and the distal end portion of the first arm portion 302b is a free end. The proximal end portion of the first arm portion 302b is an end portion of the first arm portion 302b on the side connected to the base body main body portion 302a, and the distal end portion of the first arm portion 302b is the proximal end portion. The opposite end.

  As shown in FIG. 10, the first arm portion 302b faces the first surface S1 of the base body portion 302a in a cross section perpendicular to the first surface S1. That is, the first arm 302b is laid on the first surface S1 of the base body 302a. Accordingly, if the first surface S1 is viewed in plan, the first arm portion 302b is observed so as to overlap the first surface S1.

  As described above, since the first arm portion 302b extending from the substrate main body portion 302a overlaps the substrate main body portion 302a, when the cell stack apparatus 100 is repeatedly activated / deactivated, the coating film 304 is stressed. Accordingly, the first arm 302b can move minutely together with the coating film 304. As a result, stress applied to the coating film 304 can be relieved, so that the coating film 304 can be prevented from being peeled off from the substrate 302.

  It is preferable that at least a part of the first arm portion 302b is separated from the first surface S1. That is, it is preferable that there is a gap between the base body portion 302a and the first arm portion 302b. Accordingly, the mobility of the first arm portion 302b can be improved, so that the peeling of the coating film 304 can be further suppressed. In FIG. 10, the coating film 304 enters the gap between the base body main part 302 a and the first arm part 302 b, but the chromium oxide film 303 may be filled or a gap may be formed. However, there may be no gap between the substrate body 302a and the first arm 302b.

  The total length L1 of the first arm portion 302b is preferably larger than the maximum thickness T1 of the first arm portion 302b. Accordingly, the mobility of the first arm portion 302b can be improved, so that the peeling of the coating film 304 can be further suppressed. As shown in FIG. 10, the total length L1 of the first arm portion 302b is the x-axis when the boundary between the base body portion 302a and the first arm portion 302b is defined by a virtual line X1 parallel to the x-axis direction. It is the length of the line which connected the midpoint of the 1st arm part 302b in the direction parallel to a direction. The maximum thickness T1 of the first arm portion 302b is a direction parallel to the x-axis direction when the boundary between the base material main body portion 302a and the first arm portion 302b is defined by a virtual line X1 parallel to the x-axis direction. This is the maximum thickness of the first arm portion 302b. The total length L1 of the first arm portion 302b is particularly preferably at least twice the maximum thickness T1 of the first arm portion 302b. Thereby, the mobility of the first arm portion 302b can be particularly improved. Although the total length L1 of the 1st arm part 302b is not restrict | limited in particular, For example, it can be set as 5-100 micrometers. Although the maximum thickness T1 of the 1st arm part 302b is not restrict | limited in particular, For example, it can be set as 1-20 micrometers.

  Such a 1st arm part 302b can be formed by making a damage | wound on the 1st surface S1 of the base-material main-body part 302a diagonally, for example by press work. Alternatively, the first arm portion 302b is formed by forming a convex portion protruding from the first surface S1 by blasting or pressing, and extending the convex portion from the proximal end side to the distal end side of the first arm portion with a roller or the like. it can.

  The second arm part 302c is connected to the base body part 302a. The second arm portion 302c is formed integrally with the base body portion 302a. The second arm part 302c extends from the base body part 302a. The proximal end portion of the second arm portion 302c is a fixed end, and the distal end portion of the second arm portion 302c is a free end.

  As shown in FIG. 10, the second arm portion 302c faces the second surface S2 of the first arm portion 302b in a cross section perpendicular to the first surface S1. That is, the second arm portion 302c is laid on the second surface S2 of the first arm portion 302b. Therefore, the second arm portion 302c is disposed so as to overlap the second surface S2 of the first arm portion 302b when the first surface S1 of the base body portion 302a is viewed in plan. The second surface S2 of the first arm portion 302b is an outer surface of the first arm portion 302b opposite to the base body portion 302a.

  As described above, since the second arm portion 302c extending from the substrate main body portion 302a overlaps the first arm portion 302b, when stress is applied to the coating film 304, not only the first arm portion 302b but also the second arm portion 302b. The arm portion 302 c can also move with the coating film 304. As a result, the stress applied to the coating film 304 can be further relaxed, so that the coating film 304 can be further prevented from peeling off from the substrate 302.

  In the present embodiment, the distal end side of the second arm portion 302c faces the second surface S2 of the first arm portion 302b, and the proximal end portion side of the second arm portion 302c faces the first surface S1 of the base body portion 302a. However, the entire second arm 302c may be opposed to the second surface S2 of the first arm 302b.

  It is preferable that at least a part of the second arm portion 302c is separated from the second surface S2 of the first arm portion 302b. That is, it is preferable that a gap exists between the first arm portion 302b and the second arm portion 302c. Accordingly, the mobility of the second arm portion 302c can be improved, so that the peeling of the coating film 304 can be further suppressed. In FIG. 10, the coating film 304 enters the gap between the first arm portion 302b and the second arm portion 302c, but may be filled with a chromium oxide film 303 or may be a void. However, there may be no gap between the first arm portion 302b and the second arm portion 302c.

  The total length L2 of the second arm portion 302c is preferably larger than the maximum thickness T2 of the second arm portion 302c. Accordingly, the mobility of the second arm portion 302c can be improved, so that the peeling of the coating film 304 can be further suppressed. The full length L2 and the maximum thickness T2 of the second arm portion 302c are defined in the same manner as the full length L1 and the maximum thickness T1 of the first arm portion 302b described above. The total length L2 of the second arm portion 302c is particularly preferably at least twice the maximum thickness T2 of the second arm portion 302c. As a result, the mobility of the second arm 302c can be particularly improved. Although the total length L2 of the 2nd arm part 302c is not restrict | limited in particular, For example, it can be set as 5-100 micrometers. Although the maximum thickness T2 of the 2nd arm part 302c is not restrict | limited in particular, For example, it can be set as 1-20 micrometers.

  Such a 2nd arm part 302c can be formed by making a damage | wound on the 2nd surface S2 of the 1st arm part 302b diagonally by press work, for example. Or the 2nd arm part 302c can be formed by arranging the convex part which protruded from 1st surface S1 side by side by blast processing or press work, and extending a convex part from the base end side of an arm part to the front end side with a roller etc. .

  Although not shown in FIG. 10, the base material 302 is preferably provided with a plurality of arm portions having the same configuration as the first arm portion 302b. Each of the plurality of arm portions acts so as to relieve the stress applied to the coating film 304, similarly to the first arm portion 302b. The plurality of arm portions are preferably arranged in a predetermined direction (for example, the y-axis direction or the z-axis direction) when the first surface S1 of the base body portion 302a is viewed in plan. Accordingly, when stress in a predetermined direction (for example, the y-axis direction or the z-axis direction) is likely to be applied to the coating film 304, the stress can be effectively relaxed by the plurality of arm portions. The peeling of 304 can be particularly suppressed. The plurality of arm portions are not limited to the y-axis direction and the z-axis direction, and may be arranged in a direction inclined with respect to the y-axis direction, for example.

(Modification of the embodiment)
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-described embodiment, the case where the metal member for an electrochemical cell according to the present invention is applied to the current collecting member 301 of a horizontally striped fuel cell is described. can do. Vertically-striped fuel cells are arranged on the other main surface of the conductive support substrate, the power generation unit (fuel electrode, solid electrolyte layer, and air electrode) disposed on one main surface of the support substrate. Interconnector. The metal member for an electrochemical cell according to the present invention can be applied to a solid oxide electrochemical cell including a solid oxide electrolytic cell in addition to a fuel cell.

[Modification 2]
In the above embodiment, the case where the electrochemical cell metal member according to the present invention is applied to the current collecting member 301 has been described, but the present invention can also be applied to the fuel manifold 200. However, since the insulating property is required for the fuel manifold 200, for example, alumina, silica, zirconia, crystallized glass, or the like can be used as a ceramic material constituting the coating film 304. The metal member for an electrochemical cell according to the present invention can also be applied to peripheral members of the cell stack device 100 (for example, fuel piping, air piping, air manifold, etc.).

[Modification 3]
In the said embodiment, although the metal member for electrochemical cells which concerns on this invention was applied to the current collection member 301, the specific structure of the current collection member 301 can be changed suitably. For example, the current collecting member 301 may have three or more joint portions, and a through hole may not be formed in the joint portion.

[Modification 4]
In the above embodiment, referring to FIGS. 9 and 10, the first arm portion 302b and the second arm portion formed in the region facing the first through hole c1 on the first surface S1 of the base body portion 302a. Although 302c was demonstrated, the position in which the 1st arm part 302b and the 2nd arm part 302c are formed is not restricted especially. For example, the 1st arm part 302b and the 2nd arm part 302c may be formed in the area | region which faced the fuel cell 300 among 1st surface S1 of the base-material main-body part 302a.

[Modification 5]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and side surfaces continuous to the first main surface and the second main surface. The side surface includes a first region on the first fuel cell 300a side and a second region on the opposite side to the first fuel cell 300a. The first region occupies a range of about 10 to 90% of the side surface. The second region occupies a range of about 10 to 90% of the side surface.

  Here, the surface roughness in the second region can be made larger than the surface roughness in the first region. According to this configuration, the covering film 304 is more easily formed on the side surface of the current collecting member 301 in the second region than in the first region. As a result, since the second region is surely covered with the coating film 304, even if the oxidizing gas is supplied to the outer surface of the first fuel cell 300a, the oxidation in the second region can be suppressed.

  In this modification, it is preferable that the thickness of the coating film 304 in the second region is larger than the thickness of the coating film 304 in the first region. By comprising in this way, oxidation can be further suppressed in a region that is easily exposed to the oxidant gas. The thickness of the coating film 304 in the first region is preferably thicker than the thickness of the coating film 304 in the second region. By comprising in this way, when the base-material main-body part 302a is the metal containing chromium, by suppressing the volatilization of chromium from a main-body part in the area | region near the 1st fuel cell 300a, it is 1st. Chromium poisoning in the fuel cell 300a can be further suppressed. In addition, the surface roughness in the second region is preferably larger than the surface roughness in the first and second main surfaces.

[Modification 6]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and side surfaces continuous to the first main surface and the second main surface. The side surface includes a first region on the first fuel cell 300a side and a second region on the opposite side to the first fuel cell 300a. The first region occupies a range of about 10 to 90% of the side surface. The second region occupies a range of about 10 to 90% of the side surface.

  Here, the surface roughness in the first region can be larger than the surface roughness in the second region. According to this configuration, since the surface roughness in the first region is larger than the surface roughness in the second region among the side surfaces of the current collecting member 301, peeling of the coating film 304 can be suppressed in the first region. . Further, since the surface roughness of the second region is smaller than the surface roughness of the first region, the surface area of the second region, which is easily oxidized when an oxidant gas is flowed to the outer surface of the first fuel cell 300a, is reduced. Can suppress oxidation.

  In this modification, the thickness of the coating film 304 in the first region is preferably larger than the thickness of the coating film 304 in the second region. By comprising in this way, when the base-material main-body part 302a is a metal containing chromium, the chromium poisoning in the 1st fuel cell 300a is suppressed more by suppressing the volatilization of chromium from a main-body part more. be able to. The thickness of the coating film 304 in the second region is preferably thicker than the thickness of the coating film 304 in the first region. By comprising in this way, oxidation can be further suppressed in a region that is easily exposed to the oxidant gas. In addition, the surface roughness in the first region is preferably larger than the surface roughness in the first and second main surfaces.

[Modification 7]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and a pair of side surfaces continuous to the first main surface and the second main surface. .

  Here, the area of the second main surface can be made smaller than the area of the first main surface. According to this configuration, the second main surface on the side exposed to the oxidant gas among the pair of main surfaces of the current collecting member 301 has a smaller area than the first main surface. For this reason, compared with the current collection member 301 which has the 2nd main surface of the same area as a 1st main surface like the past, the 2nd main surface can be covered with the coating film 304 more reliably. Further, since the first main surface has a larger area than the second main surface, the junction area between the current collecting member 301 and the first fuel cell 300a is increased, and the electrical resistance can be reduced.

  In the present modification, in the cross section perpendicular to the first main surface, the pair of side surfaces are preferably inclined so as to approach each other toward the second main surface. According to this configuration, since the bonding area between the pair of side surfaces and the coating film 304 is larger than when the pair of side surfaces are not inclined, the bonding strength with the coating film 304 can be improved. Moreover, it is preferable that the angle which a 2nd main surface and at least one side surface make is an obtuse angle. A corner portion, which is a boundary portion between the second main surface and the side surface, is disposed at a position that is easily exposed to the oxidant gas flowing on the outer surface of the first fuel cell 300a. By making the angle of the corner between the second main surface and the side surface an obtuse angle, the coating film 304 can be easily formed on the corner and the coating film 304 can be more reliably formed.

[Modification 8]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and side surfaces continuous to the first main surface and the second main surface.

  Here, the main body portion further includes a protruding portion protruding in a direction in which the first main surface faces from a corner portion formed by the first main surface and the side surface, and a curved surface connecting the second main surface and the side surface. It may be. According to this configuration, since the main body portion has the protruding portion that protrudes toward the first fuel cell 300a, the adhesion between the main body portion and the coating film 304 can be improved. As a result, peeling of the coating film 304 can be suppressed. Further, since the corner on the opposite side to the protrusion is formed by a curved surface, the coating film 304 can be easily formed, and the coating film 304 can be more reliably formed.

[Modification 9]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and side surfaces continuous to the first main surface and the second main surface.

  Here, the main body further includes a protruding portion that protrudes in a direction in which the second main surface faces from a corner portion formed by the second main surface and the side surface, and a curved surface that connects the first main surface and the side surface. It may be. According to this configuration, since the first main surface and the side surface are connected by the curved surface on the first fuel cell 300a side, the first main surface and the side surface are directly connected to form a corner portion. As compared with the main body portion, current concentration can be suppressed. As a result, oxidation in this part can be suppressed. In addition, since the protruding portion protrudes in a direction in which the second main surface faces from the corner portion formed by the second main surface and the side surface, the protruding portion is preferentially oxidized to suppress oxidation of other portions. it can.

[Modification 10]
The current collecting member 301 has a main body portion constituted by a base material 302 and a chromium oxide film 303. The main body has a first main surface facing the first fuel cell 300a side, a second main surface opposite to the first main surface, and side surfaces continuous to the first main surface and the second main surface. The side surface includes a first region on the first fuel cell 300a side and a second region on the opposite side to the first fuel cell 300a. The first region occupies a range of about 10 to 90% of the side surface. The second region occupies a range of about 10 to 90% of the side surface.

  Here, the side surface may have a step portion formed between the first region and the second region. According to this configuration, the stepped portion can improve the adhesion with the coating film 304, and therefore, peeling of the coating film 304 from the main body portion can be suppressed.

  In this modification, it is preferable that the step portion is oriented in the direction in which the second main surface is oriented. In this case, in the cross section perpendicular to the first main surface, the pair of side surfaces of the main body portion is preferably inclined so as to approach each other toward the second main surface. If the angle formed by the direction in which the step portion faces and the direction in which the second main surface faces is within 45 degrees, it can be said that the step portion faces in the direction in which the second main surface faces. Further, the step portion faces the direction in which the first main surface faces. In this case, in a cross section perpendicular to the first main surface, it is preferable that the pair of side surfaces of the main body portion be inclined so as to approach each other toward the first main surface. If the angle between the direction in which the step portion faces and the direction in which the first main surface faces is within 45 degrees, it can be said that the step portion faces in the direction in which the first main surface faces.

  In this modification, when the side surface is viewed along the direction orthogonal to the side surface, the end portion of the first region on the second main surface side and the end portion of the second region on the first main surface side overlap each other. Thus, it is preferable that the step portion is configured. According to this configuration, since the adhesion between the stepped portion and the coating film 304 is further improved, the peeling of the coating film 304 from the main body portion can be more reliably suppressed.

100 Cell stack 102 Conductive bonding material 200 Fuel manifold 300 Fuel cell 300a First fuel cell 300b Second fuel cell 301 Current collecting member 302 Base material 302a Base body portion S1 First surface 302b First arm portion S2 First 2 surface 302c second arm part 303 chromium oxide film 304 coating film

Claims (8)

A substrate composed of an alloy material containing chromium;
A coating film for coating the substrate;
With
The substrate, in a cross section perpendicular to the surface of the substrate, and the substrate main body, extending from a surface of the substrate main body, and a first arm portion that will be covered by the covering film,
The first arm portion is opposed to the surface of the base body portion in the cross section .
Metal parts for electrochemical cells. At least a portion of said first arm portion, in the cross section, apart from the surface of the substrate main body,
The metal member for an electrochemical cell according to claim 1. The substrate is in the cross section, extending from a surface of the substrate main body, a second arm portion that will be covered by the covering film,
The second arm portion faces the surface of the first arm portion in the cross section .
The metal member for an electrochemical cell according to claim 1 or 2. The base has a plurality of arms including the first arm,
Each of the plurality of arm portions extends from the surface of the base material main body, and faces the surface of the base material main body in the cross section,
The plurality of arm portions are arranged in a predetermined direction in a plan view of the surface of the base body portion .
The metal member for an electrochemical cell according to any one of claims 1 to 3. In the cross section , the total length of the first arm portion is larger than the maximum thickness of the first arm portion,
The metal member for electrochemical cells according to any one of claims 1 to 4. In the cross section , the total length of the first arm portion is not less than twice the maximum thickness of the first arm portion.
The metal member for an electrochemical cell according to claim 5. Two electrochemical cells,
The metal member for an electrochemical cell according to any one of claims 1 to 6,
With
The electrochemical cell metal member is a current collecting member for electrically connecting the two electrochemical cells.
Cell stack. An electrochemical cell;
The metal member for an electrochemical cell according to any one of claims 1 to 6,
With
The electrochemical cell metal member is a manifold that supports a base end of the electrochemical cell.
Cell stack device.

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