JP2014072035A - Cell stack, fuel battery module, and fuel battery device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cell stack capable of improving strength, a fuel battery module, and a fuel battery device.SOLUTION: In a cell stack, an oxygen electrode layer 10 and a collector member 4 of a fuel battery cell 3, and an interconnector layer 11 and the collector member 4 of the fuel battery cell 3 are joined with a conductive joining material 13 comprising a material system same as a material comprising the oxygen electrode layer 10, and the thickness of a conductive joining material 13a joining the interconnector layer 11 and the collector member 4 is thicker than the thickness of a conductive joining material 13b joining the oxygen electrode layer 10 and the collector member 4.

Description

  The present invention relates to a cell stack, a fuel cell module, and a fuel cell device.

  In recent years, as next-generation energy, a plurality of fuel cells that generate power at a high temperature of 600 to 1000 ° C. using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air, etc.) are electrically connected via a current collecting member. In general, cell stacks connected in series are known. And it is known to join a fuel battery cell and a current collection member using a conductive joining material (see, for example, Patent Document 1).

  The cell stack of Patent Document 1 is configured to have an interconnector layer on one side of the fuel battery cell and an oxygen electrode layer on the other side, and the interconnector layer side of the fuel battery cell and the current collecting member And between the oxygen electrode layer side of the fuel cell and the current collecting member are joined by a conductive joining material.

JP 2005-339904 A

  Conventionally, when producing a cell stack, a portion where the interconnector layer side of the fuel cell and the current collecting member are joined via a conductive joining material, the oxygen electrode layer side of the fuel cell and the current collecting member, There is a portion where the two are bonded via a conductive bonding material. For this reason, the joining strength between the current collector and the current collecting member may be different between the one side and the other side of the fuel cell, and there is a risk of peeling at the portion where the joining strength between the fuel cell and the current collecting member is the lowest. There is a problem that the strength of the cell stack is lowered.

  An object of this invention is to provide the cell stack which can improve an intensity | strength, a fuel cell module, and a fuel cell apparatus.

  A cell stack device according to the present invention includes a plurality of fuel cells having an oxygen electrode layer on one side of a solid electrolyte layer and a fuel electrode layer on the other side, and an interconnector layer electrically connected to the fuel electrode layer. And a current collecting member that is arranged between the plurality of fuel cells and electrically connects the adjacent fuel cells, the oxygen electrode layer of the fuel cells, the current collecting member, and the The interconnector layer of the fuel cell and the current collecting member are joined by a conductive joining material made of the same material system as the material constituting the oxygen electrode layer, and the interconnector layer and the current collecting member The thickness of the conductive bonding material for bonding the electrode is larger than the thickness of the conductive bonding material for bonding the oxygen electrode layer and the current collector.

  The fuel cell module of the present invention is characterized in that the cell stack is stored in a storage container.

  The fuel cell device of the present invention is characterized in that the fuel cell module and an auxiliary machine for operating the fuel cell module are housed in an outer case.

  According to the cell stack of the present invention, the oxygen electrode layer and the current collecting member of the fuel cell and the interconnector layer and the current collecting member of the fuel cell are made of the same material system as the material constituting the oxygen electrode layer. Since the bonding strength between the oxygen electrode layer and the current collecting member is higher than the bonding strength between the interconnector layer and the current collecting member, the bonding strength between the interconnector layer and the current collecting member is increased. Although it tends to be relatively low, the thickness of the conductive bonding material for bonding the interconnector layer and the current collecting member is larger than the thickness of the conductive bonding material for bonding the oxygen electrode layer and the current collecting member. In addition, the bonding strength between the interconnector layer and the current collecting member is improved, and the bonding strength between the oxygen electrode layer and the current collecting member can be approached. As a whole, the strength of the cell stack can be improved and the long-term reliability can be improved. Thereby, a fuel cell module and a fuel cell device with improved long-term reliability can be provided.

The cell stack apparatus is shown, (a) is a side view, (b) is an enlarged cross-sectional view showing a part of (a). FIG. 2 shows a fuel cell of the cell stack device of FIG. 1, wherein (a) is a cross-sectional view, and (b) is a side view of the state where the interconnector layer is omitted as viewed from the interconnector layer side. FIG. 2 is an excerpt of a current collecting member of the cell stack device of FIG. 1, (a) is a perspective view, and (b) is a cross-sectional view taken along line BB of (a). (A) is a cross-sectional view showing a state in which a pair of fuel cells are electrically connected by a current collecting member, (b) is an explanatory view showing an application region of a conductive bonding layer in an oxygen electrode layer, (c) ) Is an explanatory view showing an application region of a conductive bonding layer in an interconnector layer. It is a longitudinal cross-sectional view which shows the state which joined a pair of fuel battery cell with the electroconductive joining material through the current collection member. It is an external appearance perspective view which decomposes | disassembles and shows the fuel cell module formed by accommodating the cell stack apparatus shown in FIG. 1 in a storage container. It is a perspective view which shows the fuel cell apparatus formed by accommodating the fuel cell module shown in FIG. 6 in an exterior case.

  FIG. 1 shows a cell stack device 1, and the cell stack device 1 has a cell stack 2. 1 to 7, in order to facilitate understanding, the cross-sectional view shows the thickness enlarged and reduced, and the side view shows the length and width enlarged and reduced.

  The cell stack device 1 includes a fuel electrode layer 8 that is an inner electrode layer on one main surface of a generally columnar conductive support 7 having a pair of opposing main surfaces, a solid electrolyte layer 9, It has a solid oxide fuel cell 3 provided with a power generation section in which an oxygen electrode layer 10 as an outer electrode layer is laminated in this order. A plurality of gas flow paths 12 are provided inside the conductive support 7.

  The fuel cell 3 has a columnar shape (hollow flat plate shape) in which the interconnector layer 11 is laminated on a portion of the other main surface where the oxygen electrode layer 10 is not formed. By arranging the current collecting members 4 between adjacent fuel cells 3 in a single row, a cell stack 2 is formed by electrically connecting the fuel cells 3 in series.

  Although the fuel cell 3 and the current collecting member 4 will be described in detail later, the fuel cell 3 and the current collecting member 4 are joined via a conductive joining material 13, whereby a plurality of fuel cells 3 are electrically connected via the current collecting member 4. And the cell stack 2 is formed by mechanically joining.

Also, a P-type semiconductor layer (not shown) can be provided on the outer surface of the interconnector layer 11. By connecting the current collecting member 4 to the interconnector layer 11 via the P-type semiconductor layer, the contact between them becomes an ohmic contact, and the potential drop can be reduced. This P-type semiconductor layer may also be provided on the outer surface of the oxygen electrode layer 10.

  That is, as can be understood from the shape shown in FIG. 2, the conductive support 7 includes a pair of parallel flat surfaces n and arcuate surfaces (side surfaces) m that connect the pair of flat surfaces n respectively. It consists of Both surfaces of the flat surface n are formed substantially parallel to each other, and a porous fuel electrode layer 8 is provided so as to cover one flat surface n (lower surface) and the arcuate surfaces m on both sides. A dense solid electrolyte layer 9 is laminated so as to cover the electrode layer 8. A porous oxygen electrode layer 10 is laminated on the solid electrolyte layer 9 so as to face the fuel electrode layer 8.

  In other words, the fuel electrode layer 8 and the solid electrolyte layer 9 are connected to the other flat surface n (upper surface) from one flat surface n of the conductive support 7 via the arcuate surfaces m at both ends of the conductive support 7. The both ends of the interconnector layer 11 are joined to the upper side of the both ends of the solid electrolyte layer 9, surround the conductive support 7 with the solid electrolyte layer 9 and the interconnector layer 11, and circulate inside. The fuel gas is configured not to leak to the outside.

  And the lower end part of each fuel cell 3 which comprises the cell stack 2 is in the gas tank 6 for supplying fuel gas to the fuel cell 3 via the gas flow path 12 provided in the inside of the fuel cell 3 The cell stack device 1 is configured by being fixed by a sealing material (not shown) such as glass.

  In the cell stack device 1 shown in FIG. 1, a hydrogen-containing gas flows as fuel gas in the gas flow path 12 of the fuel cell 3, and an oxygen-containing gas (for example, air) flows between the fuel cells 3. It becomes. As a result, the fuel gas is supplied from the gas tank 6 to the fuel electrode layer 8, and the oxygen-containing gas is supplied to the oxygen electrode layer 10 through the inside of the current collecting member 4, thereby generating power in the fuel cell 3.

  The cell stack device 1 includes an elastically deformable conductive member 5 having a lower end fixed to a gas tank 6 so as to sandwich the cell stack 2 from both ends in the arrangement direction x of the fuel cells 3. Here, the conductive member 5 shown in FIG. 1 has a flat plate portion 5 a provided so as to be positioned at both ends of the cell stack 2 and a shape extending outward along the arrangement direction x of the fuel cells 3. And a current extraction part 5b for extracting a current generated by the power generation of the cell stack 2 (fuel cell 3). The arrangement direction x of the fuel cells 3 is also the flow direction of the current generated by the cell stack device 1.

Below, each member which comprises the fuel cell 3 is demonstrated. As the fuel electrode layer 8, generally known ones can be used. Porous conductive ceramics such as ZrO ₂ (referred to as stabilized zirconia) in which a rare earth element is dissolved and Ni and / or NiO are used. And can be formed from

The solid electrolyte layer 9 has a function as an electrolyte that bridges electrons between the electrodes, and at the same time, has to have a gas barrier property in order to prevent leakage between the fuel gas and the oxygen-containing gas. , 3 to 15 mol% of rare earth elements are formed from ZrO ₂ as a solid solution. In addition, as long as it has the said characteristic, you may form using other materials, such as a lanthanum gallate.

The oxygen electrode layer 10 is not particularly limited as long as it is generally used. For example, the oxygen electrode layer 10 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The oxygen electrode layer 10 needs to have gas permeability, and can have an open porosity of 20% or more, particularly 30 to 50%. The oxygen electrode layer 10 can be formed from at least one of lanthanum manganese-based (LaSrMnO ₃ ), lanthanum ferrite-based (LaSrFeO ₃ ), lanthanum cobalt-based (LaSrCoO ₃ ), etc., in which Mn, Fe, Co, etc. are present at the B site. .

The interconnector layer 11 can be formed from conductive ceramics, but since it is in contact with a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air or the like), the interconnector layer 11 needs to have reduction resistance and oxidation resistance. Yes, lanthanum chromite (LaCrO ₃ ) can therefore be used. The interconnector layer 11 is made of a material system different from the material constituting the oxygen electrode layer 10 and is not limited to a lanthanum chromite material.

  The interconnector layer 11 is dense in order to prevent leakage of fuel gas flowing through the plurality of gas flow paths 12 formed in the conductive support 7 and oxygen-containing gas flowing outside the conductive support 7. The relative density should be 93% or more, particularly 95% or more.

  The conductive support 7 needs to be gas permeable in order to allow the fuel gas to pass to the fuel electrode layer 8 and further to be conductive in order to collect current through the interconnector layer 11. Is done. Therefore, as the conductive support 7, it is necessary to use a material that satisfies this requirement. For example, conductive ceramics or cermet can be used.

  In the production of the fuel battery cell 3, when the conductive support 7 is produced by simultaneous firing with the fuel electrode layer 8 or the solid electrolyte layer 9, an iron group metal component and an inorganic oxide such as a specific rare earth The conductive support 7 can be formed from the oxide. Further, the conductive support 7 preferably has an open porosity of 30% or more, particularly 35 to 50% in order to have the required gas permeability, and the conductivity is 50 S / cm or more. Further, it may be 300 S / cm or more and 440 S / cm or more.

Furthermore, as a P-type semiconductor layer (not shown), a layer made of a transition metal perovskite oxide can be exemplified. Specifically, those having higher electron conductivity than lanthanum chromite constituting the interconnector layer 11, for example, lanthanum manganese-based (LaSrMnO ₃ ), lanthanum ferrite-based (LaSrFeO) in which Mn, Fe, Co, etc. are present at the B site. ₃ ), P-type semiconductor ceramics composed of at least one of lanthanum cobalt (LaSrCoO ₃ ) and the like can be used. In general, the thickness of such a P-type semiconductor layer is preferably in the range of 30 to 100 μm.

  The conductive bonding material 13 is provided for bonding the fuel cell 3 and the current collecting member 4, and is made of the same material system as the material forming the oxygen electrode layer 10. The phrase “consisting of the same material system as that of the oxygen electrode layer 10” not only includes the same material system but also includes the case where other inorganic oxides are added thereto. Thereby, the bonding strength between the oxygen electrode layer 10 and the conductive bonding material 13 is increased.

  Specifically, the conductive bonding material 13 may be lanthanum manganese, lanthanum ferrite, lanthanum cobalt, or the like. These materials may be used as a single material, or two or more types may be combined to produce the conductive bonding material 13. Furthermore, lanthanum manganese-based, lanthanum ferrite-based, lanthanum cobalt-based, and the like may be used in which other inorganic oxides are added in order to improve strength.

The conductive bonding material 13 may have a particle size of 0.5 to 3 μm. You may comprise by the same material system from which a particle size differs. If a different particle size is used, the particle size of the fine particles is 0
. It is preferable that the particle diameter is 1 to 0.5 μm and the coarse particle diameter is 1.0 to 3.0 μm. Thus, by producing the conductive bonding material 13 using materials having different particle sizes, coarse particles having a large particle size improve the strength of the conductive bonding material 13, and fine particles having a small particle size are made conductive. The sinterability of the bonding material 13 can be improved.

  Next, the current collecting member 4 will be described with reference to FIG. The current collecting member 4 includes a plurality of plate-like first cell facing portions 4a1 joined to one adjacent fuel cell 3 and plates extending from both sides of the first cell facing portion 4a1 so as to be separated from the fuel cells. First plate-like separation portion 4a2, a plurality of plate-like second cell facing portions 4b1 joined to the other adjacent fuel cell 3, and from both sides of the second cell facing portion 4b1 so as to be separated from the fuel cells. And an extended plate-like second separation portion 4b2.

  Further, the first connecting portion 4c that connects one ends of the plurality of first spacing portions 4a2 and the plurality of second spacing portions 4b2, and the other ends of the plurality of first spacing portions 4a2 and the plurality of second spacing portions 4b2. The second connecting portion 4d to be connected is a set of units, and a plurality of sets of these units are connected in the longitudinal direction of the fuel cell 3 by a conductive connecting piece 4e. As shown in FIG. 4A, the first cell facing portion 4a1 and the second cell facing portion 4b1 are portions that are joined to the fuel cell 3 and these portions allow the power generation current of the fuel cell 3 to enter and exit. It is a part to do.

  That is, the fuel cell 3 and the first and second cell facing portions 4a1, 4b1 of the current collecting member 4 are joined by the conductive joining materials 13a, 13b. FIG. 4A shows a state in which a pair of fuel cells 3 are joined by a current collecting member 4.

  As shown in FIG. 4C, the conductive bonding materials 13a and 13b are formed in the surface region of the interconnector layer 11, and the formation area of the conductive bonding material 13b formed in the oxygen electrode layer 10 is as follows. The formation area of the conductive bonding material 13a formed on the interconnector layer 11 is larger. Further, the thickness of the conductive bonding material 13a that joins the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 is such that the oxygen electrode layer 10 and the second cell facing portion 4b1 of the current collecting member 4 are joined. It is thicker than the thickness of the conductive bonding material 13b. 4B, the state in which the second cell facing portion 4b1 of one current collecting member 4 is bonded to the conductive bonding material 13b on the oxygen electrode layer 10 is shown in FIG. The state which the 1st cell facing part 4a1 of the one current collection member 4 has joined to the electroconductive joining material 13a on the interconnector layer 11 is shown.

  That is, the fuel electrode layer 8 and the solid electrolyte layer 9 extend from one flat surface n of the conductive support 7 to the other flat surface n (upper surface) via the arcuate surfaces m at both ends of the conductive support 7. In order to make the power generation part as wide as possible, the oxygen electrode layer 10 formed on the solid electrolyte layer 9 is formed on one flat surface of the conductive support 7 as shown in FIG. The conductive support 7 is formed on the entire surface except for both ends in the length direction L, and the conductive bonding material 13 b is also formed on the entire oxygen electrode layer 10. Since the formation area of the conductive bonding material 13b is large, the conductive bonding material 13b is firmly bonded to the oxygen electrode layer 10 and the bonding strength between the oxygen electrode layer 10 and the current collecting member 4 can be improved.

  In addition, since the conductive bonding material 13b is made of the same material system as the oxygen electrode layer 10, the conductive bonding material 13b also functions as an oxygen electrode layer and can improve conductivity and the like. Further, the porous oxygen electrode layer 10 side of the conductive bonding material 13b is porous, but the current collecting member 4 side is denser than the oxygen electrode side, so that the bonding strength with the current collecting member 4 is increased. While being able to improve, the electroconductive joining material 13b has cushioning properties and can suppress peeling of the current collecting member 4 from the fuel cell 3.

On the other hand, the interconnector layer 11 is formed over the entire length direction L of the conductive support 7 on a part of the other flat surface n of the conductive support 7 as shown in FIG. Has been. Since the interconnector layer 11 is electrically connected to the fuel electrode layer 8, it is necessary to provide the interconnector layer 11 on the conductive support 7. For this reason, the interconnector layer 11 is formed on a part of the other flat surface n of the conductive support 7. ing. Furthermore, since conductive ceramics such as lanthanum manganese, lanthanum ferrite, and lanthanum cobalt, which are the same material system as the oxygen electrode layer 10, are used as the conductive bonding material, the conductive bonding material is removed from the surface region of the interconnector layer 11. When it protrudes and is formed on the solid electrolyte layer 9, a power generation portion is formed in this portion, and the power generation amount of the fuel cell is reduced. Except for the portion, a layer of the conductive bonding material 13b is formed.

  Thereby, the width in the width direction B of the conductive support 7 of the conductive bonding material 13 b provided on the oxygen electrode layer 10 is the same as that of the conductive bonding material 13 a provided on the interconnector layer 11. 7 is formed wider than the width in the width direction B.

  And the thickness of the layer of the conductive bonding material 13a for bonding the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 to the oxygen electrode layer 10 as shown in FIG. 4 (a) and FIG. And the second cell facing portion 4b1 of the current collecting member 4 are formed thicker than the thickness of the layer of the conductive bonding material 13b.

  In other words, the distance between the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 is wider than the distance between the oxygen electrode layer 10 and the second cell facing portion 4b1 of the current collecting member 4.

  According to such a cell stack, since the conductive bonding materials 13a and 13b are made of the same material system as the material constituting the oxygen electrode layer 10, the second cell of the oxygen electrode layer 10 and the current collecting member 4 is used. Although the bonding strength between the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 tends to be smaller than the bonding strength between the facing portion 4b1, the first of the interconnector layer 11 and the current collecting member 4 tends to be smaller. The thickness of the layer of the conductive bonding material 13a that bonds the cell facing portion 4a1 is larger than the thickness of the layer of the conductive bonding material 13b that bonds the oxygen electrode layer 10 and the second cell facing portion 4b1 of the current collector 4. Since it is thick, the bonding strength between the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 is improved, and the bonding strength between the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 is reduced to the oxygen electrode. Second layer of layer 10 and current collecting member 4 Can be brought close to the bonding strength between the facing portion 4b1, it can improve the strength of the cell stack 2 as a whole, can be improved long-term reliability. Thereby, a fuel cell module and a fuel cell device with improved long-term reliability can be provided.

  Further, since the formation area of the conductive bonding material 13 a formed on the oxygen electrode layer 10 is larger than the formation area of the conductive bonding material 13 a formed on the interconnector layer 11, the oxygen electrode layer 10 and the current collecting member 4. In order to correspond to this, the thickness of the conductive bonding material 13a for bonding the interconnector layer 11 and the first cell facing portion 4a1 of the current collecting member 4 to the oxygen electrode layer 10 is increased. It is possible to improve the bonding strength between the interconnector layer 11 and the current collecting member 4 by making it thicker than the thickness of the conductive bonding material 13b that joins the second cell facing portion 4b1 of the current collecting member 4.

  In the fuel cell 3, as described above, the portion where the fuel electrode layer 8 and the oxygen electrode layer 10 face each other through the solid electrolyte layer 9 is a portion that generates power. Therefore, in order to efficiently collect the current generated by the power generation unit of the fuel cell 3, the length of the current collecting member 4 along the longitudinal direction of the fuel cell 3 is the oxygen electrode layer in the fuel cell 3. It is preferable that the length is equal to or greater than 10 in the longitudinal direction.

  The current collecting member 4 needs to have heat resistance and conductivity, and can be made of a metal or an alloy. In particular, the current collecting member 4 can be produced from an alloy containing Cr at a rate of 4 to 30% because it is exposed to a high-temperature oxidizing atmosphere, such as an Fe—Cr alloy or an Ni—Cr alloy. Can be produced.

  Further, since the current collecting member 4 is exposed to a high-temperature oxidizing atmosphere when the cell stack apparatus 1 is operated, an oxidation-resistant coating may be applied to the surface of the current collecting member 4. Thereby, deterioration of the current collecting member 4 can be reduced. It is preferable to apply the oxidation resistant coating to the entire surface of the current collecting member 4. Thereby, it can suppress that the surface of the current collection member 4 is exposed to high temperature oxidation atmosphere.

  Here, a method for producing the current collecting member 4 will be described. A single rectangular plate member is pressed to form a plurality of slits extending in the width direction of the plate member in the longitudinal direction of the plate member. And the current collection member shown in FIG. 3 is made to protrude alternately by the site | part between the slits used as the 1st cell facing part 4a1, the 1st cell separation part 4a2, the 2nd cell facing part 4b1, and the 2nd cell separation part 4b2. 4 can be produced.

  Next, the fuel cell module 20 in which the cell stack device 1 is stored in the storage container 21 will be described with reference to FIG.

  A fuel cell module 20 shown in FIG. 6 includes a reformer 22 for reforming raw fuel such as natural gas or kerosene to generate fuel gas in order to obtain fuel gas used in the fuel cell 3. It is arranged above the cell stack 2. The fuel gas generated by the reformer 22 is supplied to the gas tank 6 through the gas flow pipe 23 and supplied to the gas flow path 12 provided inside the fuel battery cell 3 through the gas tank 6. .

  FIG. 6 shows a state in which a part (front and rear surfaces) of the storage container 21 is removed and the cell stack device 1 and the reformer 22 housed inside are taken out rearward. Here, in the fuel cell module 20 shown in FIG. 6, the cell stack device 1 can be slid and stored in the storage container 21.

  Further, the oxygen-containing gas introduction member 24 provided inside the storage container 21 is disposed between a pair of cell stacks 2 juxtaposed in the gas tank 6 in FIG. 6, and the oxygen-containing gas flows into the fuel gas. Accordingly, the oxygen-containing gas is supplied to the lower end side of the fuel cell 3 so that the fuel cell 3 flows laterally from the lower end side toward the upper end side. The surplus fuel gas (fuel offgas) that has not been used for power generation discharged from the gas flow path 12 of the fuel cell 3 is burned above the fuel cell 3, thereby effectively increasing the temperature of the cell stack 2. And the activation of the cell stack device 1 can be accelerated. Further, the reformer 22 disposed above the cell stack 2 is burned above the fuel cell 3 by burning the fuel gas discharged from the gas flow path 12 of the fuel cell 3 and not used for power generation. Can be warmed. Thereby, the reforming reaction can be efficiently performed in the reformer 22.

  Next, a fuel cell device 25 in which the fuel cell module 20 and an auxiliary machine (not shown) for operating the fuel cell module 20 are housed in an outer case will be described with reference to FIG.

  The fuel cell device 25 shown in FIG. 7 has a module housing chamber in which an outer case made up of struts 26 and an outer plate 27 is vertically divided by a partition plate 28 and the upper side of the fuel cell module 20 is housed above. 29, and the lower side is configured as an auxiliary equipment storage chamber 30 for storing auxiliary equipment for operating the fuel cell module 20. In addition, the auxiliary machine accommodated in the auxiliary machine storage chamber 30 is abbreviate | omitted.

Further, the partition plate 28 is provided with an air circulation port 31 for flowing the air in the auxiliary machine storage chamber 30 to the module storage chamber 29 side, and a part of the exterior plate 27 constituting the module storage chamber 29 An exhaust port 32 for exhausting air in the module storage chamber 29 is provided.

  Although the present invention has been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention.

  For example, in the cell stack apparatus 1 described above, the example in which the fuel gas is supplied to the gas flow path 12 of the fuel battery cell 3 and the oxygen-containing gas is supplied to the outside of the fuel battery cell 3 has been shown. An oxygen-containing gas may be supplied and the fuel gas may be supplied to the outside of the fuel battery cell. In that case, a fuel battery cell having an inner electrode layer as an oxygen electrode layer and an outer electrode layer as a fuel electrode layer may be used. In this case, the bonding strength between the fuel electrode layer as the outer electrode layer and the conductive bonding material can be improved by setting the components of the conductive bonding material to the same composition as that of the fuel electrode layer.

  Furthermore, although the hollow flat plate fuel cell 3 is used in the above embodiment, a cylindrical fuel cell or a flat plate fuel cell can also be used.

  Moreover, in the said form, although the current collection member 4 as shown in FIG. 3 was used, it is not limited to this. Although it has the 1st connection part 4c and the 2nd connection part 4d in FIG. 3, the case where it has any one connection part may be sufficient.

1: cell stack device 2: cell stack 3: fuel cell 4: current collecting member 4a1: first cell facing portion 4b1: second cell facing portion 6: gas tank 8: fuel electrode layer 9: solid electrolyte layer 10: oxygen electrode Layer 11: interconnector layers 13, 13a, 13b: conductive bonding material 20: fuel cell module 25: fuel cell device

Claims (4)

  A plurality of fuel cells each having an oxygen electrode layer on one side of the solid electrolyte layer, a fuel electrode layer on the other side, and an interconnector layer electrically connected to the fuel electrode layer, and the plurality of fuel cells A current collecting member that is disposed between and adjacent to each other and electrically connects the fuel cells, and an oxygen electrode layer of the fuel cells, the current collecting member, and an interconnector layer of the fuel cells The conductive bonding material is bonded to the current collecting member by a conductive bonding material made of the same material system as the material constituting the oxygen electrode layer, and joins the interconnector layer and the current collecting member. The cell stack is characterized by being thicker than the thickness of the conductive bonding material for bonding the oxygen electrode layer and the current collecting member.   The cell stack according to claim 1, wherein a formation area of the conductive bonding material formed on the oxygen electrode layer is larger than a formation area of the conductive bonding material formed on the interconnector layer.   A fuel cell module comprising the cell stack according to claim 1 stored in a storage container.   4. A fuel cell device comprising: the fuel cell module according to claim 3; and an auxiliary machine for operating the fuel cell module, housed in an outer case.

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