JP2007250281A - Fuel cell stack device, fuel cell stack connecting device, and fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack device ensuring connection reliability with a fuel cell stack, reducing power loss in a current drawing out part, preventing peeling off of a current collecting member, and preventing deterioration in power generation output. <P>SOLUTION: In the fuel cell stack device having the fuel cell stack 22 formed by arranging a plurality of solid oxide fuel cells 2 through a current collecting member 3 and electrically connecting them, and an end current collecting member 24 installed at both ends in the arranging direction of the fuel cell, a metallic member 23 is arranged on the outside of the end current collecting member, and the current drawing out part 23 extending in a belt shape from one part of the metallic member toward the outside is installed. One end of the metallic member is joined and fixed to a manifold 11 in an insulated state, and one part of the current drawing out part is fixed to the manifold with an insulating fixing agent. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell stack apparatus including a fuel cell stack in which solid oxide fuel cells are arranged in a row and electrically connected to each other and a current drawing structure from an end thereof.

In recent years, various types of fuel cells in which a stack of a plurality of solid oxide fuel cells is accommodated in a storage container have been proposed as next-generation energy.
FIG. 9A is a side view schematically showing a fuel cell stack apparatus 1 having a conventional fuel cell stack 10. The fuel cell stack 10 is configured by arranging a plurality of solid oxide fuel cells 2, and adjacent fuel cells 2 are electrically connected by an intervening current collecting member 3. It is fixed to the manifold 11. The fuel cell stack device 1 is further configured by disposing current drawing members 3a for taking out current at both ends. The conventional current drawing member 3a is a conductive and relatively flexible wire member attached to the end current collecting members 3b located at both ends.

  FIG. 9B is a partially enlarged plan view of the fuel cell stack device 1 of FIG. Although the cross section of the fuel battery cell 2 is shown, this is an example. The fuel cell 2 includes a fuel electrode 5, a solid electrolyte layer 6, and an oxygen electrode 4 stacked on one flat surface of a columnar conductive support substrate 8 having a pair of flat surfaces, and an interconnector on the other flat surface. 7 is provided. A plurality of fuel gas passages 9 are formed in the conductive support substrate 8 along the axial direction. The current collecting member 3 is in contact with the oxygen electrode of one fuel battery cell 2 and the interconnector 7 of the other fuel battery cell 2 and is fixed with a conductive adhesive. An end current collecting member 3b at the end is provided on the end side of the fuel cell 2 located at the end in the arrangement direction. A current drawing member 3a, which is a relatively flexible conductive wire member, is attached to the end portion current collecting member 3b. Such a conventional current drawing member is disclosed in Patent Document 1, for example.

At both ends of the fuel cell stack 10, pressing plates 13 made of a plate-like insulator are disposed, and the lower ends of the pair of pressing plates 13 are fixed to the side surfaces of the manifold 11, thereby the fuel cell stack. One end of each fuel cell 2 in the axial direction is fixed by a glass sealing material 12 on the upper surface of the manifold 11 in a state where a pressing force is applied to both ends of the fuel cell 10.
JP 2003-308857 A

The end current collecting structure in the conventional fuel cell stack device has the following problems.
The current drawing member, which is a relatively flexible wire, is likely to vibrate and swing, so that an external force is also transmitted to the end current collecting member at the end of the fuel cell stack, and this end current collecting member There was a risk of peeling. As a result, the power generation output decreases.
-The end current collecting member is usually the same as the current collecting member disposed between the cells, and the current collecting member needs to be thin in terms of its structure. The drawer member had to be attached to such a thin end current collector. For this reason, in order to perform reliable electrical connection, the current drawing member cannot be made too thick. As a result, the electric resistance could not be made sufficiently small and the power loss was large.

  SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a fuel cell stack device having an end current collecting structure that can perform reliable electrical connection with a fuel cell stack and has low power loss.

In order to solve the above problems, the present invention provides the following configurations.
(1) A fuel cell stack device according to claim 1 is a fuel cell stack in which a plurality of solid oxide fuel cells are arranged and electrically connected via a current collecting member, and the fuel cell. In the fuel cell stack device having end current collecting members provided at both ends in the arrangement direction of
A metal member is disposed outside the end current collecting member, and a current drawing portion extending in a strip shape from a part of the metal member to the outside is provided.
(2) The fuel cell stack device according to claim 2 has a manifold for fixing one end of the fuel cell in claim 1,
One end of the metal member is bonded and fixed to the manifold in an insulated state.
(3) The fuel cell stack device according to claim 3 has a manifold for fixing one end of the fuel cell according to claim 1 or 2,
A part of the current drawing portion is fixed to the manifold by an insulating adhesive.
(4) The fuel cell stack device according to claim 4 is the fuel cell stack device according to any one of claims 1 to 3, wherein the metal member is opposed to a surface on an end portion side of the fuel cell located at the end. And a pair of side plate portions which are bent from both side edges of the flat plate portion and extend outward.
(5) The fuel cell stack connection device according to claim 5 is arranged such that two or more fuel cell stack devices according to any one of claims 1 to 4 are juxtaposed with the arrangement direction of the fuel cells parallel to each other. In addition, the metal members of each of the fuel cell stack devices are connected to each other by a conductive connecting member.
(6) A fuel cell according to a sixth aspect includes the fuel cell stack device according to any one of the first to fourth aspects or the fuel cell stack connection device according to the fifth aspect in a storage container. A fuel cell characterized by comprising:

  According to the first aspect of the present invention, the metal member is disposed outside the end current collecting member in the fuel cell stack device, and the strip-shaped current extraction member is attached to the outside from a part of the metal member. However, compared with the conventional flexible wire, there is no fear of detachment and it is stable. Further, since the current drawing member does not exert an external force on the end current collecting member, it is possible to eliminate the possibility of the end current collecting member peeling off. Furthermore, since the thickness of the metal member can be set sufficiently thick, the electric resistance can be reduced and the power loss can be reduced.

  In the invention of claim 2, since one end portion of the metal member is fixed to the manifold in an insulated state, the metal member is stably supported while ensuring insulation with the manifold, and the metal member is a fuel cell. It can also serve as a pressing plate that presses the stack from both sides in the cell arrangement direction.

  According to the invention of claim 3, by fixing a part of the current drawing portion to the manifold with an insulating fixing material, the stability of the whole metal member including the current drawing portion can be enhanced and insulation with the manifold can be secured. .

  In the invention of claim 4, the metal member has a shape including a flat plate portion and a pair of side plate portions bent outward from both side edges thereof, so that a rigid and strong structure can be obtained and stable. Can stand up.

  In the invention of claim 5, by connecting the metal members of the fuel cell stacks in a plurality of rows with the conductive connecting member, it is possible to efficiently take out the current while saving space.

  In the invention of claim 6, a stable power generation output can be obtained in the fuel cell in which the fuel cell stack device having the above-described effects is housed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1A is a side view schematically showing a fuel cell stack device 21 having a fuel cell stack 22. The fuel cell stack 22 is configured by arranging a plurality of solid oxide fuel cells 2 in a line, and adjacent fuel cells 2 are electrically connected by an intervening current collecting member 3. . For convenience of explanation, the longitudinal direction of the columnar fuel cell 2 is referred to as an axial direction. In the example shown in the drawing, the end current collecting member 24 connected to the end side surface of the fuel cell 2 located at the endmost part is different from the current collecting member 3 in the middle part. Yes. This will be described with reference to FIG. In FIG. 1A, the current collecting member 3 and the end current collecting member 24 are simplified for convenience.

  In the present invention, the metal member 23 is disposed on the outer side of the end current collecting members 24 provided at both ends of the fuel cell stack 22 so as to face the end side surface of the fuel cell 2 located at the end. Is arranged. The metal member 23 is formed of a heat-resistant alloy that is advantageous in terms of cost. A surface 23 a of the metal member 23 facing the fuel cell stack 22 is electrically connected to the outermost fuel cell 2 via the end current collecting member 24. The connection between the metal member 23 and the end current collecting member 24 may include a conductive ceramic material to prevent local concentration of current.

One end portion of the metal member 23 in the axial direction is erected on the upper surface of the manifold 11 like the one end portion of each fuel cell 2 in the axial direction, and is bonded and fixed by a glass sealing material that is an insulating material. Thereby, electrical insulation between the metal member 23 and the manifold 11 is ensured.
The metal member 23 of the present invention also serves as the conventional presser plate 13 shown in FIG. 9, and the pair of metal members 23 and 23 press the fuel cell stack 22 from both sides in the cell arrangement direction. It is fixed.

  FIG. 1B is a partially enlarged plan view of the fuel cell stack device 1 of FIG. The structure of the fuel cell 2 and the current collecting member 3 are the same as those described with reference to FIG.

  The metal member 23 includes a flat plate portion 23 that comes into contact with the end current collecting member 24, and a pair of side plate portions 23b and 23b that are bent from both side edges of the flat plate portion 23 and extend outward substantially perpendicular to the flat plate portion 23. It comprises. Accordingly, as shown in the plan view of FIG. 1B, the metal member 23 has a U-shaped cross section. This shape is suitable for increasing the rigidity of the metal member 23 and standing up stably.

  Further, a strip-shaped current extraction portion 23c extends from the front end side of one side plate portion 23b in a direction parallel to the arrangement direction of the fuel cells. Since the current extraction part 23c is a part of the metal member 23 and is integrated, the current extraction part 23c is stable with no fear of detachment. A current lead wire is connected to the tip of the current extraction portion 23c.

  In the fuel cell stack device 21 shown in FIG. 1, the current generated by the power generation in the fuel cell stack 22 flows through the metal member 23 from the end current collecting member 24, and from the front end of the current extraction portion 23c to the outside. It is taken out. The metal member 23 can be in contact with the end current collecting member 24 over the entire flat plate portion having a large area and the thickness thereof can be sufficiently increased. Therefore, the resistance can be reduced and the power loss can be reduced.

  2A (a) and 2 (b) are plan views showing examples of the end current collecting member 24, respectively. The end current collecting member 24 is provided such that the spring constant in the cell arrangement direction is smaller than that of the current collecting member 3 in the intermediate portion. Specifically, as a method of reducing the spring constant, for example, in FIG. 2A (a), a current collecting member 24A having a wider distance w and width (vertical direction in the drawing) than the current collecting member 3 is used. Further, in FIG. 2A (b), a current collecting member 24B in which two current collecting members 3 at the intermediate portion are connected in a stacked manner is used. By reducing the spring constant of the end current collecting member 24, the followability to deformation is improved, and peeling of the current collecting member 24 is prevented. This is because the endmost portion is easily affected by external force, and the variation in the distance between the fuel cell 2 at the endmost portion and the metal member 23 tends to be large.

  FIG. 2B is a partially enlarged perspective view of the current collecting member 3 shown in FIG. 2A. Two adjacent fuel cells in the fuel cell stack will be referred to as a first cell and a second cell, respectively, and the current collecting member 3 includes a first conductor piece 301 that contacts the flat surface of the first cell, A second conductor piece 302 extending obliquely from one end of the first cell to the other end of the second cell, a third conductor piece 303 contacting the flat surface of the second cell, and a second A fourth conductor piece 304 extending from one end of the cell to the other end of the first cell is provided as a basic element. The ends of the first to fourth conductor pieces are connected one after another in this order, and further, the conductor pieces are connected repeatedly in this order, so that a continuous current collector extending in the axial direction is obtained. The member 3 is formed. The current collecting member 3 having such a shape is rich in flexibility, has good followability to deformation between cells and in the cell axis direction, and at the same time has excellent air permeability.

  FIG. 3 is a view showing still another embodiment of the metal member 23 of FIG. The metal member 31 also has a substantially U-shaped cross section, and includes a flat plate portion 31a and a pair of side plate portions 31c and 31b that bend and extend from both side edges. A feature of the embodiment of FIG. 3 is that a strip-shaped current extraction portion 32 is bent from the vicinity of the lower end of the flat plate portion 31a so as to protrude perpendicularly to the flat plate portion 31a. Furthermore, the front end portion of the current drawing portion 32 is bent obliquely downward. Furthermore, a pair of vertically extending leg portions 33, 33 are provided at the lower end of the metal member 31, and these leg portions are buried in the sealing material on the manifold so that they can stand up stably. .

  FIG. 4 is a view showing still another embodiment of the metal member 23 of FIG. 1, similarly to FIG. 3. The difference from the metal member 31 of FIG. 3 is the shape of the current extraction portion 42 of the metal member 41. The strip-shaped current extraction portion 42 protrudes and extends perpendicularly to the flat plate portion 41a, bends downward at the middle portion, and then bends again in a direction perpendicular to the flat plate portion 41a. As a result, one step portion 43 is formed in the intermediate portion of the current extraction portion 42.

  FIG. 5 is a view showing a state in which the metal members 31 and 41 shown in FIGS. 3 and 4 are incorporated in the fuel cell stack device 21. 5 (a) is a plan view, FIG. 5 (b) is a front view, FIG. 5 (c) is an enlarged sectional view of part A of FIG. 5 (b), and FIG. 5 (d) is an enlarged sectional view of part B of FIG. FIG. The flat plate portion 31a of the metal member 31 and the flat plate portion 41a of the metal member 41 are fixed to the upper surface of the manifold 11 by the glass sealing material 53 with the fuel cell stack 22 sandwiched from both ends (FIG. 5C). And (d)).

  As shown in FIG. 5C, a part of the lower surface of the strip-shaped current extraction portion 42 extending from the metal member 41 is fixed to the upper portion of the manifold 11 by an insulating fixing material 51. Thereby, the stability of the metal member 41 is strengthened, and the structure is more resistant to vibration and external force. A glass sealing material may be used as the insulating fixing material 51. Since the step portion 43 of the current extraction portion 42 has a shape along the upper outline of the manifold 11, the manifold 11 and the current extraction portion 42 do not come into contact with each other at a constant distance, and insulation is ensured. The

Similarly, as shown in FIG. 5D, a part of the lower surface of the strip-shaped current extraction portion 32 extending from the metal member 31 is also fixed to the upper portion of the manifold by the insulating fixing material 51. The shape of the current extraction portion 32 is also a shape along the upper outline of the manifold 11.
In this way, the shape of the current extraction part is appropriately set so as to follow the upper outline shape of the manifold 11.

  FIG. 6 is a diagram showing an embodiment of an end current collecting member when two fuel cell stacks 22 and 22 are juxtaposed with each other with the arrangement directions of the respective fuel cells parallel to each other. 6 (a) is a plan view, FIG. 6 (b) is a front view, FIG. 6 (c) is a right side view, and FIG. 6 (d) is an illustration of the metal member 41 shown in FIG. FIG. 6E is an enlarged cross-sectional view corresponding to FIG. 5C when used for the portion, and FIG. 6E shows FIG. 5 when the metal member 31 shown in FIG. 3 is used for the end of the fuel cell stack 22. It is an expanded sectional view equivalent to (d).

  As shown in FIG. 6A, the same type of metal members 31 and 41 are used at the end portions on the same side of both fuel cell stacks 22 and 22, respectively. And the end of each metal member 31 is mutually connected by the connection member 54 in the edge part side which provided the metal member 31. FIG. As shown in FIG. 3, a connecting hole is formed at the tip of the metal member 31. As shown in FIG. 6E, screws 55 are inserted and screwed from both ends of the connecting member 54 using this connection hole. In this way, a plurality of fuel cell stacks 22 can be connected in series, and current can be taken out collectively.

  FIGS. 7A to 7D are views showing still another embodiment of the metal member 23 of FIG. FIG. 7E is an enlarged cross-sectional view corresponding to FIG. 5D when the metal member 61 is used at the end of the fuel cell stack 22, and FIG. FIG. 6 is an enlarged cross-sectional view corresponding to FIG. 5 (d) when used at the end of the battery cell stack 22.

  The metal member 61 and the metal member 71 shown in FIG. 7A and FIG. 7B, respectively, are box-shaped with sections forming the flat plate portions 61a and 71a being rectangular. In addition, fixing pieces 62 and 72 for fixing to the manifold 11 extend perpendicularly to the flat plate portions 61a and 71a in the vicinity of the lower end. The manifold 11 is fixed as shown in FIG. In the present embodiment, the current drawing parts 63 and 73 are provided separately from the fixed pieces 62 and 72. In the metal member 61, the current extraction part 63 extends perpendicularly to the flat plate part 61a from the central part of the side surface of the box part. On the other hand, in the metal member 71, the current drawing portion 73 extends in parallel with the flat plate portion 71a from the central portion of the side surface of the box portion.

  The metal member 81 and the metal member 91 shown in FIG. 7C and FIG. 7D, respectively, include only flat plate portions 81a and 91a and no side plate portions. Legs 84 and 94 are provided at the lower end. The fixing pieces 82 and 92 for fixing to the manifold 11 are the same as the metal member 61 and the metal member 71. Further, the same applies to the metal members 61 and 71 for the current drawing portions 83 and 93.

  FIG. 8 is a cross-sectional view in a direction perpendicular to the axial direction, showing an example of a joining form of the end current collecting member 24 of the fuel cell stack and the metal member 101 of the present invention. The end current collecting member 24 and the flat plate portion 101 a of the metal member 101 are bonded with the conductive adhesive 103. At this time, a plurality of holes 102 are formed in advance in the flat plate portion 101 a of the metal member 101. The conductive adhesive 103 passes through the hole 102 and enters the back surface side of the flat plate portion 101a. And it hardens | cures in the state which expanded to the circumference larger than the diameter of the hole 102 and formed the bulging part 104. The hardened bulging portion 104 exhibits the same effect as a rivet, and mechanically and electrically firmly joins the current collecting member 24 and the metal member 101. The structure shown in FIG. 8 can be applied to any of the metal members described above.

(A) is a side view which shows roughly the fuel cell stack apparatus which has a fuel cell stack. It is a partially expanded plan view of the fuel cell stack device of (a). (A) And (b) is a top view which shows the Example of an edge part current collection member, respectively. It is a partial expansion perspective view of the current collection member shown in FIG. 2A. It is a figure which shows another embodiment of the metal member of FIG. It is a figure which shows another embodiment of the metal member of FIG. 1 similarly to FIG. It is a figure which shows the state which assembled the metal member shown in FIG.3 and FIG.4 in the fuel cell stack apparatus, respectively. (A) is a plan view, (b) is a front view, and (c) and (d) are enlarged sectional views of an end portion of a fuel cell stack using a metal member. It is a figure which shows embodiment of a metal member at the time of arranging two fuel battery cell stacks so that the arrangement direction of each fuel battery cell may be mutually parallel. (A) is a plan view, (b) is a front view, (c) is a right side view, and (d) is an enlarged cross-sectional view of an end portion of a fuel cell stack using the metal member shown in FIG. (E) is an expanded sectional view of the edge part of the fuel cell stack using the metal member shown in FIG. (A)-(d) is a figure which shows another embodiment of the metal member of FIG. It is sectional drawing of the direction perpendicular | vertical to an axial direction which shows an example of the joining form of the edge part current collection member of a fuel cell stack, and the metal member of this invention. (A) is a side view which shows roughly the fuel cell stack apparatus which has the conventional fuel cell stack. (B) is a partially enlarged plan view of the fuel cell stack device of (a).

Explanation of symbols

21 Fuel cell stack device 22 Fuel cell stack 23, 31, 41, 61, 71, 81, 91, 101 Metal member

Claims (6)

A fuel cell stack in which a plurality of solid oxide fuel cells are arranged and electrically connected via current collecting members, and end current collecting members provided at both ends in the arrangement direction of the fuel cells, respectively In a fuel cell stack device having
A fuel cell stack device, comprising: a metal member disposed outside the end current collecting member; and a current extraction portion extending outward from a part of the metal member in a band shape. Having a manifold for fixing one end of the fuel cell,
2. The fuel cell stack device according to claim 1, wherein one end portion of the metal member is bonded and fixed to the manifold in an insulated state. Having a manifold for fixing one end of the fuel cell,
3. The fuel cell stack device according to claim 1, wherein a part of the current drawing portion is fixed to the manifold with an insulating adhesive. 4.   The metal member has a flat plate portion disposed to face the end portion side surface of the fuel cell positioned at the end, and a pair of side plate portions that are bent from both side edges of the flat plate portion and extend outward. The fuel cell stack device according to any one of claims 1 to 3, further comprising:   The fuel cell stack device according to any one of claims 1 to 4, wherein two or more fuel cell stack devices are juxtaposed with the arrangement direction of the fuel cells parallel to each other, and the metal members of each of the fuel cell stack devices are A fuel cell stack connection device, wherein the fuel cell stack connection devices are connected to each other by conductive connection members.   A fuel cell comprising the fuel cell stack device according to any one of claims 1 to 4 or the fuel cell stack connection device according to claim 5 accommodated in a storage container.

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