JP2012227104A - Fuel battery cell device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel battery cell device configured to suppress separation between a collector member and a fuel battery cell.SOLUTION: The fuel battery cell device includes: a fuel battery cell; a collector member 4 having recesses 15 in the surface thereof; and a conductive bonding material which is disposed partially inside the recesses 15, and bonds the fuel battery cell and the collector member 4. When the recesses 15 are viewed in an optional cross-section including individual openings of the recesses 15, each of the recesses 15 includes an inflow part behind a surface thereof located inwardly of the opening and around the opening. A part of the conductive bonding material is stored in the inflow part.

Description

  The present invention relates to 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 ° C. to 1000 ° C. using a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air, etc.) are installed through current collecting members. 2. Description of the Related Art There are known fuel cell devices that are installed and electrically connected in series. 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).

JP 2005-339904 A

  However, when the fuel cell and the current collecting member are joined via the conductive joining material, the surface of the current collecting member is flat, so the joining strength between the current collecting member and the conductive joining material is weak, There has been a problem that the current collecting member and the fuel cell are peeled off when the fuel cell device is manufactured or transported.

  The fuel battery cell device of the present invention comprises a fuel battery cell, a current collecting member having a recess on the surface, and a conductive bonding material partly provided in the recess and joining the fuel battery cell and the current collecting member. The recessed portion has an inflow portion located behind the surface around the opening portion inward of the opening portion when viewed in cross section in an arbitrary cross section including the opening portion of the recessed portion. A part of the bonding material is accommodated.

  ADVANTAGE OF THE INVENTION According to this invention, the joining strength of a current collection member and an electroconductive joining material can be improved, and peeling with a current collection member and a fuel cell can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the fuel cell apparatus which is one Embodiment of this invention, (a) is a side view which shows a fuel cell apparatus roughly, (b) is a top view which expands and shows a part of (a) It is. It is a perspective view which extracts and shows the current collection member shown in FIG. (A) is the sectional view on the AA line of the current collection member shown in FIG. 2, (b) is the sectional view on the BB line of the current collection member shown in FIG. It is an expanded sectional view which expands and shows the current collection part of the current collection member shown in FIG.3 (b). It is a longitudinal cross-sectional view which shows the joining state of the fuel cell and current collection member in the fuel cell apparatus shown in FIG. It is a longitudinal cross-sectional view which shows the joining state of the fuel cell and current collection member in the fuel cell apparatus which concerns on other embodiment of this invention. It is an expanded sectional view which expands and shows the current collection part of the current collection member which comprises the fuel cell apparatus which is other embodiment of this invention. It is a longitudinal cross-sectional view which extracts and shows a part of fuel cell apparatus comprised using the current collection member shown in FIG. It is an external appearance perspective view which decomposes | disassembles and shows the fuel cell module formed by accommodating the fuel battery cell 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. 9 in an exterior case.

  A fuel cell device 1 according to a first embodiment of the present invention will be described with reference to FIG.

  The fuel cell device 1 (hereinafter sometimes referred to as a cell stack device 1) has a gas flow path 12 inside and has a pair of opposed main surfaces as a whole in a columnar conductive support. A fuel cell including a power generation unit in which a fuel electrode layer 8 that is an inner electrode layer, a solid electrolyte layer 9, and an air electrode layer 10 that is an outer electrode layer are laminated in this order on one main surface of the body 7. 3. The fuel cell 3 has a columnar shape (hollow flat plate shape) formed by laminating the interconnector 11 at a portion of the other main surface where the outer electrode layer is not formed. By arranging the current collecting member 4 between the adjacent fuel cells 3 arranged in a row, the cell stack 2 is provided in which the fuel cells 3 are electrically connected 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.

  Further, a P-type semiconductor layer (not shown) can be provided on the outer surface of the interconnector 11. By connecting the current collecting member 4 to the interconnector 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 air electrode layer 10.

  And the lower end of each fuel cell 3 constituting the cell stack 2 is connected to a gas tank 6 for supplying fuel gas to the fuel cell 3 via the gas flow path 12 provided inside the fuel cell 3. It is fixed by a sealing material (not shown) such as glass.

  In the cell stack device 1 shown in FIG. 1, the hydrogen-containing gas flows through the gas flow path 12 of the fuel cell 3 as a fuel gas, and the inside of the current collecting member 4 disposed between the fuel cells 3 An oxygen-containing gas (air) flows. 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 air electrode layer 10 through the inside of the current collecting member 4, thereby generating power in the fuel cell 3. In the following description, the outer electrode layer is described as the air electrode layer 10 and the inner electrode layer is described as the fuel electrode layer 8.

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

  Below, each member which comprises the fuel cell 3 shown in FIG. 1 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 another material etc.

The air electrode layer 10 is not particularly limited as long as it is generally used. For example, the air electrode layer 10 can be formed of a conductive ceramic made of a so-called ABO ₃ type perovskite oxide. The air electrode layer 10 needs to have gas permeability, and can have an open porosity of 20% or more, particularly 30 to 50%.

Although the interconnector 11 can be formed from conductive ceramics, it needs to have reduction resistance and oxidation resistance because it comes in contact with a fuel gas (hydrogen-containing gas) and an oxygen-containing gas (air, etc.). Therefore, lanthanum chromite (LaCrO ₃ ) can be used. The interconnector 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 is preferably 93% or more, particularly 95% or more.

  The conductive support 7 is required to be gas permeable in order to permeate the fuel gas up to the fuel electrode layer 8 and to be conductive in order to collect current through the interconnector 11. The Therefore, as the conductive support 7, it is necessary to use a material that satisfies this requirement, and for example, conductive ceramics, cermets, and the like can be used.

  When the fuel cell 3 is manufactured, in the case where the conductive support 7 is manufactured by co-firing with the fuel electrode layer 8 or the solid electrolyte layer 9, the conductivity is made from the iron group metal component and the specific rare earth oxide. A support 7 can be formed. 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 11, for example, lanthanum manganite (LaSrMnO ₃ ), lanthanum ferrite (LaSrFeO ₃ ) in which Mn, Fe, Co, etc. exist at the B site. P-type semiconductor ceramics made of at least one of lanthanum cobaltite (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 can be formed using conductive ceramics or the like. As the conductive ceramics, the same ceramics as those forming the air electrode layer 10 can be used. When the conductive ceramic is formed of the same component as the air electrode layer 10, the bonding strength between the air electrode layer 10 and the conductive bonding material 13 is increased. Since it becomes high, it is preferable to form with the same component as the air electrode layer 10.

Specifically, LaSrCoFeO ₃ , LaSrMnO ₃ , LaSrCoO ₃ or the like can be used. These materials may be produced using a single material, or the conductive bonding material 13 may be produced by combining two or more kinds.

Further, the conductive bonding material 13 may be made of different materials having different particle diameters, or may be made of different materials having the same particle diameter. Furthermore, it may be composed of the same material having different particle diameters, or may be composed of the same material having the same particle diameter. When different particle diameters are used, it is preferable that the fine particle diameter is 0.1 to 0.5 μm and the coarse particle diameter is 1.0 to 3.0 μm. Moreover, when comprising the electroconductive joining material 13 with the same particle size, it is preferable that a particle size shall be 0.5-3 micrometers.

  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 FIGS. In FIG. 2, the recess 15 provided on the surface of the current collecting member 4 is omitted. The first direction is indicated by an arrow.

  A current collecting member 4 shown in FIG. 2 includes a plurality of first current collecting pieces 4 a joined to one adjacent fuel cell 3 and a plurality of second current collecting joined to the other adjacent fuel cell 3. A piece 4b, a first connecting portion 4c for connecting ends of the plurality of first current collecting pieces 4a and a plurality of second current collecting pieces 4b, a plurality of first current collecting pieces 4a and a plurality of second current collecting pieces The second connecting portion 4d that connects the other ends of 4b is a unit, and a plurality of sets of these units are connected in the longitudinal direction of the fuel cell 3 by the conductive connecting piece 4e. . The 1st current collection piece 4a and the 2nd current collection piece 4b show the part joined to fuel cell 3, and these parts serve as current collection part 4f which takes out electric power by the power generation of fuel cell 3.

  In the fuel cell 3, as described above, the portion where the fuel electrode layer 8 and the air 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 outer 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, for example, an alloy, conductive ceramics, cermet, or the like. 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 fuel cell device 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. Moreover, you may provide also on the surface of the inner wall which comprises the recessed part 15. FIG. Even in that case, exposure of the surface of the current collecting member 4 to a high-temperature oxidizing atmosphere can be suppressed.

  When the current collecting member 4 is made of an alloy containing Cr, a Cr diffusion suppression layer (not shown) is coated on the coating in order to reduce the diffusion of Cr contained in the alloy into the fuel cell 3. May be formed. As the Cr diffusion suppressing layer, a Zn oxide or a perovskite oxide containing La and Sr can be used. It is preferable to produce the Cr diffusion suppression layer after forming a concave portion to be described later.

As shown in FIG. 3, the first current collecting piece 4a and the second current collecting piece 4b have a first surface 4g, a second surface 4h, and a third surface 4i that intersect at different angles with respect to the first direction. doing. In other words, it has the 1st surface 4g which opposes the fuel cell 3, and the 2nd surface 4h and the 3rd surface 4i which adjoin the both sides of the 1st surface 4g. And the some recessed part 15 is provided in the 2nd surface 4h and the 3rd surface 4i of the 1st current collection piece 4a and the 2nd current collection piece 4b, respectively. As shown in FIGS. 3B and 4, the recess 15 is formed in a tapered shape toward the inside, and is opposite to the first surface 4 g with respect to the first surface 4 g facing the fuel cell 3. It is provided obliquely toward the side.

  Therefore, the recess 15 provided in the second surface 4h is inward of the opening 15a and behind the surface located around the opening 15a when viewed in a cross section including the opening 15a of the recess 15. An inflow portion 15b is provided. Similarly, the recess 15 provided in the third surface 4i is behind the surface located around the opening 15a inwardly of the opening 15a when viewed in cross section including the opening 15a of the recess 15. Has an inflow portion 15b.

  Further, the concave portion 15 has a tapered shape as it goes inward from the surface of the current collecting portion 4f. In addition, as shown in FIG. 4, the recessed part 15 becomes the taper shape which carried out the cross sectional view and made the acute-angled substantially triangular shape, and the angle 15c where the recessed part 15 is tapered shall be 10-30 degrees. Is preferred. Moreover, although the cross-sectional view including the opening 15a shows a substantially triangular example, the shape of the concave portion 15 is not limited to the triangular shape. In addition, the tapered shape may be gradually reduced as it goes inward of the current collecting member 4, instead of the gradually narrowing shape.

  Here, when viewed in a cross-section in an arbitrary cross section including the opening 15a, the inflow portion is located behind the surface located inward of the opening 15a and around the second surface 4h and the third surface 4i. Then, as shown in FIG. 4, the wall of the recess located behind the surface around the second surface 4h or the third surface 4i and the opening 15a provided in the second surface 4h or the third surface 4i It means a region surrounded by a vertical line indicated by a two-dot chain line drawn from the periphery.

  The concave portion 15 is preferably provided at a depth of 5 to 100 μm (L shown in FIG. 4) from the second surface 4 h of the current collecting portion 7 f toward the inside from the viewpoint of bonding strength with the conductive bonding material 13. The opening 15a of the recess 15 is preferably provided with a size of 5 to 50 μm (W shown in FIG. 4). As a result, as described later, when a part of the conductive bonding material 13 is filled into the recess 15, it becomes easier to fill the recess 15, and the current collecting member 4 and the conductive bonding material 13 due to the anchor effect It is possible to improve the bonding strength.

  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 4 shown in FIG. 2 is producible by pulling out the site | part between the slits used as the 1st current collection piece 4a and the 2nd current collection piece 4b alternately. Then, the concave portion 15 is formed by pressing a member having a convex portion corresponding to the concave portion 15 against the second surface 4h and the third surface 4i so as to be recessed. By forming the recess 15 in a tapered shape, the recess 15 can be easily provided in the current collecting member 4.

  In addition, a convex portion corresponding to the concave portion 15 is formed on the surface facing the second surface 4h and the third surface 4i of the member that is pulled out across the portion between the slits serving as the first current collecting piece 4a and the second current collecting piece 4b. It is also possible to pull out alternately while forming the concave portion 15 by inserting the convex portion when forming and pulling out.

  Next, the joining state of the current collecting member 4 and the fuel cell 3 by the conductive joining material 13 will be described with reference to FIG.

As shown in FIG. 5, the current collecting member 4 and the fuel cell 3 are joined via a conductive joining material 13. That is, the current collecting member 4 and the fuel cell 3 are electrically and mechanically connected by the conductive bonding material 13. The conductive bonding material 13 is provided so as to be in contact with the first surface 4g, the second surface 4h, and the third surface 4i of the current collector 4f, and is in contact with the second surface 4h and the third surface 4i. A large number 13 is arranged on the side of the fuel cell 3 to be joined. Alternatively, the conductive bonding material 13 may be provided so as to completely cover the current collector 4f by covering the entire circumference of the current collector 4.

  The conductive bonding material 13 is arranged to bond the fuel cell 3 and the current collecting member 4, and is provided on the air electrode layer 10 side of the fuel cell 3 over the entire surface of the air electrode layer 10. Yes. On the interconnector 11 side of the fuel cell 3, a conductive bonding material 13 is provided over the entire surface of the interconnector 11. Note that the conductive bonding material 13 may be provided only in part of the air electrode layer 10 and the interconnector 11 to bond the current collecting member 4 and the fuel cell 3.

  Therefore, as shown in FIG. 5, the conductive bonding material 13 is accommodated in the concave portion 15, and the conductive bonding material 13 is also accommodated in the inflow portion. The bonding strength with the conductive bonding material 13 can be improved.

  The concave portion 15 is inward of the opening portion 15a and has an inflow portion behind the surface located around the opening portion 15a, and a part of the conductive bonding material 13 is accommodated in the inflow portion. . In other words, a part of the recess 15 is provided in a region outside the opening 15a as seen through the second surface 4h or the third surface 4i where the opening 15a of the current collecting member 4 is provided. The conductive bonding material 13 is also accommodated in a part of the recess 15.

  Therefore, the current collecting member 4 can improve the bonding strength between the current collecting member 4 and the fuel cell 3 in the first direction with respect to the first surface 4g, and the current collecting member 4 in the direction along the first surface 4g. The joining strength between the electric member 4 and the fuel cell 3 can be improved. Thereby, it can be set as the fuel cell apparatus 1 with improved connection reliability.

  In addition, the current collecting member 4 includes a plurality of current collecting portions 4 f for joining with adjacent fuel cells 3, and one adjacent current collecting portion joined with one fuel cell 3. The second surface 4h of 4f and the third surface 4i of the other current collector 4f adjacent to each other are arranged to face each other. And the recessed part 15 is provided in the 2nd surface 4h of the one current collection part 4f, and the 3rd surface 4i of the other current collection part 4f. In other words, the recess 15 is provided on the surface where the plurality of current collectors 4f face each other. And the recessed part 15 provided in the 2nd surface 4h and the recessed part 15 provided in the 3rd surface 4i are formed in the state inclined toward the other side of the 1st surface 4g.

  Since the recess 15 is provided on the second surface 4h of the one current collector 4f and the third surface 4i of the other current collector 4f, the arrangement direction of the current collector 4f (the direction along the first surface 4g) ), The bonding strength between the fuel cell 3 and the current collecting member 4 can be improved. Further, since the recesses 15 provided in the second surface 4h and the third surface 4i are formed in a state inclined toward the opposite side of the first surface 4g, for example, provided in the second surface 4h. Even when stress is applied in a direction extending from the opening 15a of the recessed portion 15 toward the bottom side of the recessed portion 15, the current collecting member 4 and the conductive bonding material 13 are formed by the recessed portion 15 provided on the third surface 4i. Can be prevented from peeling.

  Moreover, since the recessed part 15 is not provided in the 1st surface 4g and the recessed part 15 is provided in the 2nd surface 4h and the 3rd surface 4i, respectively, it cross | intersects a 1st direction rather than the 1st surface 4g. Many concave portions 15 are provided on the second surface 4h and the third surface i arranged along the direction in which the corners are reduced. In other words, the current collector 4f is provided with more recesses 15 on the surface having a smaller intersection angle with the first direction than on the surface having a larger intersection angle with the first direction.

Thereby, the number of recesses 15 provided on the first surface 4g facing the fuel cell 3 is
This is less than the number of recesses 15 provided on the other surface (for example, the second surface 4h or the third surface 4i) of the current collector 4f. Therefore, it is possible to improve the bonding strength between the current collecting member 4 and the conductive bonding material 13 without disturbing the current flowing in the first direction. That is, an increase in electrical resistance in the current collecting member 4 can be suppressed.

  The recesses 15 provided on each surface of the current collector 4f can be appropriately set in shape and number depending on the shape and size of the current collecting member 4. For example, when the recess 15 is provided on the first surface 4g, The opening 15a is preferably provided so as to be 1 to 5% of the area of the first surface 4g. In that case, it is preferable to provide the recess 15 provided on the second surface 4h and the third surface 4i so as to be 3 to 10% of the area of each surface.

  When the recess 15 is provided on the first surface 4g, the total area of the openings 15a of the respective recesses 15 is the sum of the areas of the openings 15a of the respective recesses 15 provided on the second surface 4h and the third surface 4i. It is preferable to provide a smaller size. Thereby, an increase in electrical resistance of the current collector 4f in the first direction can be suppressed. Furthermore, by making the depth L of the concave portion 15 provided on the first surface 4g deeper than the concave portion 15 on the other surface, the bonding strength between the current collecting member 4 and the conductive bonding material 13 is strengthened, and the electric resistance is reduced. The increase can be suppressed.

  The intersection angle between the first direction and the first surface 4g or the second surface 4h is an angle formed by the first surface 4g or the second surface 4h and a straight line along the first direction. Here, the second surface having a small intersection angle with the first direction includes those arranged obliquely with respect to the first direction, and also includes a second surface parallel to the first direction.

  Although FIG. 5 shows an example in which the recesses 15 are not provided on the first surface 4g, the recesses 15 are provided on the first surface 4g less than the recesses 15 provided on the second surface 4h or the third surface 4i. May be. Thereby, the joint strength in the first direction can be improved.

  A fuel cell device 17 (cell stack device 17) according to a second embodiment of the present invention will be described with reference to FIG.

  The cell stack device 17 is different from the cell stack device 1 in the arrangement and inclination directions of the recesses 15 provided in the current collecting member 18, and the other configuration is the same as that of the cell stack device 1. Hereinafter, similar members are denoted by the same reference numerals.

  In the current collecting member 18, the concave portion 15 provided in the second current collecting piece 18b on the side to be joined to the air electrode 10 of the fuel cell 3 is opposite to the first surface 18g of the second surface 18h and the third surface 18i. It is provided on the surface side. Further, the configuration is different from that of the current collecting member 4 in that the concave portion 15 is inclined toward the first surface 18g. That is, in the second current collecting piece 18b, the recess 15 is not provided on the first surface 18g side of the second surface 18h, and the recess 15 is on the opposite side of the second surface 18h from the first surface 18g. It is provided on a certain surface side. Similarly, the concave portion 15 provided on the third surface 18i is also provided on the surface side of the third surface 18i opposite to the first surface 18g. In the second current collecting piece 18b, the third surface 18i is provided. Of these, no recess 15 is provided on the first surface 18g side. Even in this case, the bonding strength between the conductive bonding material 13 and the current collecting member 4 can be improved.

  A current collecting member 4 ′ constituting the cell stack device 19 according to the third embodiment of the present invention will be described with reference to FIGS.

When viewed in a cross section with an arbitrary cross section including the recess 15 ', the recess 15' has a trapezoidal shape with the opening 15'a as the top surface and the bottom (not shown) as the bottom surface. The side wall which comprises comprises the taper shape which spreads outside as it goes inside. Therefore, the inflow portion 15 ′ b located inward of the opening 15 ′ a is formed on the second surface 4 ′ h or the third surface of the current collecting member 4 ′.
Located behind the periphery of the surface 4'i. In addition, the conductive bonding material 13 is filled and accommodated in the recess 15 ′.

Therefore, the filled conductive bonding material 13 is caught in the recess 15 ′ with respect to the stress generated in the conductive bonding material 13 and the current collecting member 4 ′, and the fuel cell 3 and the current collecting member 4 are bonded to each other. Strength can be improved. Also, the inflow portions 15'b in the extending direction of the first surface 4'g, respectively.
Therefore, the joining strength between the fuel cell 3 and the current collecting member 4 can be further improved.

  The bottom of the recess 15 ′ may be larger than the opening 15′a, and is preferably 1.5 to 2.5 times the size of the diameter of the opening 15′a (W shown in FIG. 7). Moreover, it is preferable that the depth (L shown in FIG. 7) of recessed part 15 'is 5-100 micrometers. Accordingly, the contact area between the conductive bonding material 13 and the inner wall of the recess 15 can be increased, and the bonding strength between the current collecting member 4 and the conductive bonding material 13 can be improved.

  Next, a joined state between the current collecting member 4 ′ and the fuel battery cell 3 will be described with reference to FIG. 8.

  The cell stack device 19 shown in FIG. 8 is different from the cell stack device 17 according to the second embodiment in that the current collecting member 4 ′ is used, and the other points are the same as the cell stack device 17.

  The current collecting member 4 ′ has a recess 15 ′ provided in the second current collecting piece 4 ′ b on the side where the fuel cell 3 is joined to the air electrode 10, and the second surface 4 of the second current collecting piece 4 ′ b. The concave portion 15 'is not provided on the first surface 4'g side of' h and the third surface 4'i, and the first surface 4'g of the second surface 4'h and the third surface 4'i The configuration is different from the current collecting member 4 in that it is provided on the opposite side. The concave portion 15 ′ provided in the current collecting member 4 ′ has a trapezoidal shape when viewed in cross section with an arbitrary cross section including the opening 15 a.

  Since the concave portion 15 'has a trapezoidal shape, the inflow portion 15'b of the concave portion 15' is inside of the opening 15'a when viewed in cross section so as to include the opening portion 15'a. Since the conductive bonding material 13 is filled, the bonding strength between the current collecting member 4 ′ and the conductive bonding material 13 can be further improved.

  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.

  The fuel cell module 20 shown in FIG. 9 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 circulation pipe 23, and a gas flow path (not shown) provided inside the fuel battery cell 3 through the gas tank 6. To be supplied.

  FIG. 9 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. 9, 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 arranged between the cell stacks 2 juxtaposed in the gas tank 6 in FIG. 9, and the oxygen-containing gas is adapted to the flow of the fuel gas. Thus, an oxygen-containing gas is supplied to the lower end portion side of the fuel cell 3 so that the fuel cell 3 flows laterally from the lower end portion side (one end portion side) toward the upper end portion side (the other end portion side). It is configured as follows. The surplus fuel gas (fuel offgas) that has not been used for power generation discharged from the gas flow path of the fuel battery cell 3 is burned above the upper end of the fuel battery cell 3, so that the temperature of the cell stack 2 is increased. As a result, the cell stack device 1 can be started up quickly. In addition, the fuel gas that has not been used for power generation discharged from the gas flow path of the fuel cell 3 is burned above the upper end of the fuel cell 3, thereby improving the fuel cell 3. The quality device 22 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. 10 has a module housing chamber 29 in which the inside of an exterior case composed of a support column 26 and an exterior plate 27 is vertically divided by a partition plate 28 and the upper side thereof houses the above-described fuel cell module 20. 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 and shown.

  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 device 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. Alternatively, an oxygen-containing gas may be supplied to the fuel cell 3 and the fuel gas may be supplied to the outside of the fuel cell 3. In that case, what is necessary is just to set it as the fuel cell 3 of the structure which makes an inner side electrode layer the air electrode layer 10, and makes an outer side electrode layer the fuel electrode layer 8. FIG. In this case, the bonding strength between the fuel electrode layer 8 as the outer electrode layer and the conductive bonding material 13 can be improved by setting the components of the conductive bonding material 13 to the same composition as that of the fuel electrode layer 8. .

  The current collection member 4 should just have the recessed part 15 in a part of surface, and the shape of the recessed part 15 is not limited. For example, even when the recess 15 has a shape such as a dent or dent, the bonding strength between the current collecting member 4 and the conductive bonding material 13 can be improved by the anchor effect, and the current collecting member 4 and the fuel cell 3 can be improved. Peeling can be suppressed.

  Furthermore, in the present specification, an example of the current collecting member 4 configured by a plurality of current collecting portions 4f formed in the longitudinal direction is shown, but the current collecting member 4 is configured by one current collecting portion 4f. Also good.

1, 17, 19: Fuel cell device 2: Cell stack 3: Fuel cell 4, 4 ', 18: Current collecting member 4a, 4'a, 18a: First current collecting piece 4b, 4'b, 18b: 2nd current collection piece 4f, 4'c, 18f: Current collection part 4g, 4'd, 18g: 1st surface 4h, 4'e, 18h: 2nd surface 4i, 4'f, 18i: 3rd surface 6 : Gas tank 13: Conductive bonding material 15, 15 ': Recess 15a, 15'a: Opening 15b, 15'b: Inflow part 20: Fuel cell module 25: Fuel cell device

Claims (2)

A fuel cell;
A current collecting member having a recess on the surface;
A part is provided in the recess, and includes a conductive bonding material that bonds the fuel cell and the current collecting member,
When the concave portion is viewed in cross section at an arbitrary cross section including the opening of the concave portion,
It has an inflow portion behind the surface located around the opening, inward of the opening, and a portion of the conductive bonding material is accommodated in the inflow portion. A fuel cell device. A plurality of the fuel cells are arranged in the first direction with the current collecting member interposed therebetween,
The current collecting member includes a first surface facing the fuel battery cell, and a second surface arranged along a direction in which an intersection angle with the first direction is smaller than the first surface,
2. The fuel cell device according to claim 1, wherein more of the recesses are provided on the second surface than on the first surface.

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