JP6290676B2 - Fuel cell - Google Patents

Description

  The present invention relates to a solid oxide fuel cell.

  As a solid oxide fuel cell, a fuel cell stack having a plurality of stacked solid oxide fuel cells and an electrode provided at an end portion in the stacking direction of the plurality of fuel cells were overlapped Some have a current collector (see, for example, Patent Document 1). In order to increase the output voltage in such a fuel cell, it is required to increase the degree of adhesion between the electrode and the current collector plate and reduce the power transmission loss between the electrode and the current collector plate.

  Further, as a technique for increasing the degree of adhesion between members in such a fuel cell, for example, there is a pressurizing mechanism described in Patent Document 2. The pressurizing mechanism includes a compression spring provided on the fuel cell stack via a pressing plate, a plate provided on the compression spring, a heat insulating plate and a pressing plate provided below the fuel cell stack, and an upper side. And a connecting rod for connecting the lower heat insulating plate and the presser plate.

JP 2007-250281 A JP 2006-339035 A

  However, in the pressurizing mechanism described in Patent Document 2, a compression spring is used. Moreover, in order to ensure the heat resistance and corrosion resistance of the compression spring, a ceramic made mainly of silicon nitride, which is generally expensive, is used for the compression spring. For this reason, the cost increases and the size is increased by using the compression spring.

  Therefore, an object of the present invention is to provide a fuel cell that can be reduced in size while suppressing an increase in cost.

In order to achieve the above object, a fuel cell according to claim 1 includes a fuel cell stack having a plurality of stacked solid oxide fuel cells, and end portions in the stacking direction of the plurality of fuel cells. A base portion that is spaced apart from the electrode provided in the stacking direction and extending from the base portion toward the fuel cell stack, and a tip portion that connects the electrode in the fuel cell stack. It is comprised by the extension part fixed to the electrode holding | maintenance part to hold | maintain, and the metal current collecting plate superimposed on the said electrode , or the said current collecting plate, an insulating material, and the said current collecting plate are said A metal plate overlapped with an insulating material interposed between the electrode and the base portion, and during the heat generation of the fuel cell stack, thermal expansion of the current collector plate, or The current collector and The collector plate in accordance with the thermal expansion of the serial metal plate and a intermediate portion which is pressed against the electrode.

According to this fuel cell, the tip of the extending portion that extends from the base portion toward the fuel cell stack is an electrode holding portion that holds the electrodes provided at the ends in the stacking direction of the plurality of fuel cells. The electrode holding part is restrained with respect to the base part by this extending part. Further, an interposition part is interposed between the electrode and the base part, and the interposition part is constituted by a metal current collecting plate superimposed on the electrode, or a current collecting plate, It is comprised with an insulating material and the metal plate piled up on the current collection board via the insulating material. The interposed portion is configured such that the current collector plate is pressed against the electrode along with the thermal expansion of the current collector plate or the thermal expansion of the current collector plate and the metal plate when the fuel cell stack generates heat.

Therefore, when the power generation heat generation of the fuel cell stack, in a state where the electrode holding portion is constrained to the base unit, the current collector plate is pressed against the electrode. Thereby, since the adhesion degree of an electrode and a current collecting plate can be raised, the power transmission loss between an electrode and a current collecting plate can be reduced.

  In addition, as described above, the current collector plate can be brought into close contact with the electrode without using a compression spring. Therefore, it is possible to reduce the size while suppressing an increase in cost because the compression spring is unnecessary.

  The fuel cell according to claim 2, further comprising a manifold that supplies fuel gas and air gas to the plurality of fuel cells, wherein the manifold includes the base portion and the extension. It is set as the structure which has a part.

  According to this fuel cell, since the base portion and the extension portion are provided in the manifold, the structure can be simplified as compared with the case where the base portion and the extension portion are provided separately from the manifold. .

The fuel cell according to claim 3 is the fuel cell according to claim 1 or 2, wherein the interposition portion is provided with the current collector plate, the insulating material, and the current collector plate via the insulating material. It is comprised by the said metal plate piled up .

  According to this fuel cell, the interposition part has a metal plate in addition to the current collector plate. Therefore, when the fuel cell stack generates heat, the metal plate is heated and thermally expanded in addition to the current collector plate, so that the current collector plate can be pressed against the electrode. Therefore, since the current collector plate, which is generally expensive such as being plated, can be reduced in thickness by having the metal plate, the cost can be reduced.

  The fuel cell according to claim 4 is the fuel cell according to claim 3, wherein at least one of the current collector plate and the metal plate is formed of a material having a higher coefficient of thermal expansion than the extension portion. Has been.

  According to this fuel cell, at least one of the current collector plate and the metal plate is formed of a material having a higher coefficient of thermal expansion than the extending portion. Accordingly, when the fuel cell stack generates heat, the amount of thermal expansion of the current collector plate and the metal plate is larger than the amount of thermal expansion of the extension portion, so that the current collector plate can be pressed more reliably against the electrode.

  The fuel cell according to claim 5 is the fuel cell according to any one of claims 1 to 4, wherein the extending portion is provided on a side of the current collector plate. .

  According to this fuel cell, since the extension portion is provided on the side of the current collector plate, it is possible to eliminate the need to provide a cutout or a hole in the current collector plate to avoid the extension portion. . Thereby, since the magnitude | size of a current collector plate can be ensured, the connection area of an electrode and a current collector plate can be ensured.

  A fuel cell according to a sixth aspect is the fuel cell according to any one of the first to fifth aspects, wherein the extending portion is provided on both sides of the current collector plate. ing.

  According to this fuel cell, since the extending portion is provided on both sides of the current collector plate, the electrode holding portion is placed on the base portion on both sides of the current collector plate by the pair of extending portions. Can be restrained against. Therefore, during power generation heat generation of the fuel cell stack, the electrode holding part is restrained with respect to the base part on both sides of the current collector plate by the extension part, and the current collector positioned between the extension parts is The plate can be pressed against the electrode. Thereby, compared with the case where an electrode holding part is restrained only by the extension part of one side, the contact degree of an electrode and a current collecting plate can be raised further, for example.

  The fuel cell according to claim 7 is the fuel cell according to any one of claims 1 to 6, wherein the extension portion is formed along a peripheral edge of the current collector plate. Yes.

  According to this fuel cell, since the extension portion is formed along the periphery of the current collector plate, the extension portion ensures a long restraint length of the electrode holding portion along the periphery of the current collector plate. can do. Thereby, since a current collecting plate can be pressed on an electrode over the circumferential direction of a current collecting plate, the adhesion degree of an electrode and a current collecting plate can be improved further.

  The fuel cell according to claim 8 is the fuel cell according to any one of claims 1 to 7, wherein a connection area between the electrode and the current collector plate is the extension portion and the electrode holding portion. It is set as the structure larger than the connection area.

  According to this fuel cell, since the connection area between the electrode and the current collector plate is larger than the connection area between the extension part and the electrode holding part, when the fuel cell stack generates power, the fuel cell stack extends from the fuel cell stack to the extension part. More heat can be transferred from the electrodes to the current collector than is transferred. Thereby, since a current collecting plate can be thermally expanded more efficiently, a current collecting plate can be pressed by an electrode with a still higher load.

  The fuel cell according to claim 9 is the fuel cell according to any one of claims 1 to 8, wherein the base portion, the extension portion, and the interposition portion are provided on one side of the fuel cell stack. It is set as the structure provided only in.

  According to this fuel cell, since the base portion, the extension portion, and the interposition portion are provided only on one side of the fuel cell stack, the degree of adhesion between the electrode on one side and the current collector plate in the fuel cell stack is increased. However, the structure can be simplified.

  The fuel cell according to claim 10 is the fuel cell according to any one of claims 1 to 9, wherein the base portion, the extension portion, and the interposition portion are on both sides of the fuel cell stack. It is set as the structure provided in each.

  According to this fuel cell, since the base portion, the extension portion, and the interposition portion are provided on both sides of the fuel cell stack, the degree of adhesion between the electrodes on both sides of the fuel cell stack and the current collector plate is set respectively. Can be increased.

In order to achieve the above object, a fuel cell according to claim 11 includes a fuel cell stack having a plurality of stacked solid oxide fuel cells and one of the stacking directions of the plurality of fuel cells. A first base portion provided apart from the first electrode provided at the end portion in the stacking direction and an end portion on the other side in the stacking direction of the plurality of fuel cells. A second base portion provided apart from the second electrode in the extending direction of the stacking direction, and extending from the first base portion to the fuel cell stack side, with a tip portion in the fuel cell stack A first extension portion fixed to an electrode holding portion for holding the first electrode; and a second portion extending from the second base portion toward the fuel cell stack, and a tip portion of the first base portion and the first extension portion. At least one of the exit A second extending portion which is constant, or is constituted by the first current collector plate made of metal that is superimposed on the first electrode, or, with the first collector plate, and the first insulating material, said first And a first metal plate superimposed on the current collector through the first insulating material , interposed between the first electrode and the first base portion , and of the fuel cell stack The first current collector plate is pressed against the first electrode along with the thermal expansion of the first current collector plate or the thermal expansion of the first current collector plate and the first metal plate during power generation heat generation . It is comprised by the metal current collector plate overlapped with the interposition part and the second electrode , or the second current collector plate, the second insulating material, and the second current collector plate It is constituted by a second metal plate superimposed over the second insulating material, between the second base portion and the second electrode Is interposed, and, when the power generation heat generation of the fuel cell stack, the thermal expansion of the second collector plate, or the second collector plate in accordance with the thermal expansion of the second collector plate and the second metal plate Comprises a second interposition part pressed against the second electrode .

According to this fuel cell, the tip of the first extending portion that extends from the first base portion to the fuel cell stack side is the first provided at the end on one side in the stacking direction of the plurality of fuel cells. The electrode holding portion is fixed to the electrode holding portion that holds the electrode, and the electrode holding portion is restrained with respect to the first base portion by the first extending portion. Further, a first interposition part is interposed between the first electrode and the first base part, and the first interposition part is constituted by a metal first current collecting plate superimposed on the first electrode. Or it is comprised by the 1st current collecting plate, the 1st insulating material, and the 1st metal plate piled up on the 1st current collecting plate via the 1st insulating material. The first interposer is configured so that the first current collector plate is first in association with the thermal expansion of the first current collector plate or the first current collector plate and the first metal plate during the heat generation of the fuel cell stack. It is the structure pressed against an electrode.

Therefore, when the power generation heat generation of the fuel cell stack, in a state where the electrode holding portion is constrained to the first base portion, the first collector plate is pressed against the first electrode. Thereby, since the close_contact | adherence degree of a 1st electrode and a 1st current collecting plate can be raised, the electric power transmission loss between a 1st electrode and a 1st current collecting plate can be reduced.

Furthermore, the tip of the second extending portion that extends from the second base portion to the fuel cell stack side is fixed to at least one of the first base portion and the first extending portion, and this second extending portion The second base portion is restrained by at least one of the first base portion and the first extension portion by the portion. Further, a second interposition part is interposed between the second electrode and the second base part, and the second interposition part is constituted by a metal second current collecting plate superimposed on the second electrode. Or it is comprised by the 2nd current collecting plate, the 2nd insulating material, and the 2nd metal plate piled up on the 2nd current collecting plate via the 2nd insulating material. The second intermediate portion is configured such that the second current collector plate is secondly expanded in accordance with the thermal expansion of the second current collector plate or the second current collector plate and the second metal plate during the heat generation of the fuel cell stack. It is the structure pressed against an electrode.

Therefore, during power generation heat generation of the fuel cell stack , the electrodes in the plurality of fuel cells are pressed against each other with the second base portion being restrained against at least one of the first base portion and the first extension portion. At the same time, the second current collector plate is pressed against the second electrode. Thereby, while being able to raise the close_contact | adherence degree of the electrodes in a some fuel cell, the close contact degree of a 2nd electrode and a 2nd collector plate can be improved. As a result, it is possible to reduce the power transmission loss between the electrodes in the plurality of fuel cells and the power transmission loss between the first electrode and the first current collector plate.

  In addition, as described above, since each member can be brought into close contact without using a compression spring, it is possible to reduce the size while suppressing an increase in cost because the compression spring is unnecessary.

  As described in detail above, according to the fuel cell of the present invention, it is possible to reduce the size while suppressing an increase in cost.

1 is a longitudinal sectional view of a fuel cell according to a first embodiment of the present invention. FIG. 2 is a plan view of a first current collector plate and a manifold shown in FIG. 1. It is a longitudinal cross-sectional view of the fuel cell which concerns on 2nd embodiment of this invention. It is a longitudinal cross-sectional view of the fuel cell which concerns on 3rd embodiment of this invention. It is a longitudinal cross-sectional view of the fuel cell which concerns on a comparative example. It is a figure which shows the result of the verification experiment performed about 1st embodiment of this invention.

[First embodiment]
First, a first embodiment of the present invention will be described.

  As shown in FIG. 1, the fuel cell 10 according to the first embodiment of the present invention includes a fuel cell stack 12, a manifold 14, a first current collector plate 16, a second current collector plate 18, and an insulating material. 20 and a metal plate 22.

  The fuel cell stack 12 includes a plurality of solid oxide fuel cells 24 stacked. In the present embodiment, as an example, the fuel cell stack 12 includes three layers of fuel cells 24, but the number of layers of the fuel cells 24 can be arbitrarily selected.

  Each fuel cell 24 includes an electrolyte layer 26 formed of a flat solid oxide, a fuel electrode 28 and an air electrode 30 respectively laminated on the front and back surfaces of the electrolyte layer 26, the electrolyte layer 26, and the fuel electrode 28. And a flat plate-like separator 32 for holding the air electrode 30. The fuel electrode 28 of one fuel cell 24 and the air electrode 30 of the other fuel cell 24 that are overlapped with each other are connected via a conductive material (not shown).

  In the separator 32, a fuel conveyance path 34 and an air conveyance path 36 extending in the thickness direction of the separator 32 on the side of the fuel electrode 28 and the air electrode 30, and a fuel conveyance groove 38 extending from the fuel conveyance path 34 along the fuel electrode 28. And an air conveyance groove 40 extending from the air conveyance path 36 along the air electrode 30 is formed.

  The manifold 14 is provided only on one side (for example, the fuel electrode 28 side) of the fuel cell stack 12. The manifold 14 includes a flat base portion 42 and a wall-like extension portion 44. The fuel electrode 28 provided at one end in the stacking direction H of the plurality of fuel cells 24 is an example of the “electrode provided at the end in the stacking direction of the plurality of fuel cells” in the present invention. The base portion 42 is provided so as to be separated from the fuel electrode 28 in the extending direction of the stacking direction H.

  The extending part 44 extends from the base part 42 to the fuel cell stack 12 side. A distal end portion 44A of the extending portion 44 is fixed to a separator 32 provided on one side in the above-described stacking direction H via a connection member 46 such as ceramic glass. The separator 32 is an example of the “electrode holding part” in the present invention.

  As shown in FIG. 2, more specifically, the extension portion 44 includes a pair of first wall portions 48 provided on both sides of the first current collector plate 16 and a first current collector plate. 16 and a second wall portion 50 that is provided on the side of 16 and connects the pair of first wall portions 48. The pair of first wall portion 48 and second wall portion 50 extend along the peripheral edge 16 </ b> A of the first current collector plate 16 formed in a rectangular flat plate shape and surround the first current collector plate 16. It has a shape.

  As shown in FIG. 1, a fuel supply path 54 and an air supply path 56 are formed in the manifold 14. The fuel supply path 54 communicates with the fuel conveyance path 34 described above, and the air supply path 56 communicates with the air conveyance path 36 described above.

  A fuel gas containing hydrogen and carbon monoxide is supplied to the fuel supply path 54 from the outside, and the fuel gas supplied to the fuel supply path 54 is supplied to the fuel electrode 28 through the fuel transfer path 34 and the fuel transfer groove 38. The On the other hand, air gas containing oxygen is supplied to the air supply path 56 from the outside, and the air gas supplied to the air supply path 56 is supplied to the air electrode 30 through the air transfer path 36 and the air transfer groove 40.

  In the air electrode 30, as shown by the following formula (1), oxygen and electrons in the air gas react to generate oxygen ions. The oxygen ions reach the fuel electrode 28 through the electrolyte layer 26.

(Air electrode reaction)
1 / 2O ₂ + 2e ⁻ → O ²⁻ (1)

  On the other hand, in the fuel electrode 28, as shown by the following formulas (2) and (3), oxygen ions that have passed through the electrolyte react with hydrogen and carbon monoxide in the fuel gas, and thereby water (steam) and carbon dioxide. Carbon and electrons are generated. Electrons generated at the fuel electrode 28 reach the air electrode 30 through an external circuit. Then, the electrons move from the fuel electrode 28 to the air electrode 30 in this manner, whereby electric power is generated in each fuel cell 24. Further, each fuel cell 24 generates heat with the above reaction during power generation.

(Fuel electrode reaction)
H ₂ + O ²⁻ → H ₂ O + 2e ⁻ (2)
CO + O ²⁻ → CO ₂ + 2e ⁻ (3)

  The first current collector plate 16 and the second current collector plate 18 are made of metal. The first current collecting plate 16 is an example of the “current collecting plate” in the present invention, and is superimposed on the fuel electrode 28 provided on one side in the stacking direction H. On the other hand, the second current collecting plate 18 is superimposed on the air electrode 30 provided on the other side in the stacking direction H (the side opposite to the first current collecting plate 16 side).

  In the following description of the present embodiment, when the fuel electrode 28 and the separator 32 are simply described, the fuel electrode 28 and the separator 32 are provided on one side (the first current collector plate 16 side) in the stacking direction H. The fuel electrode 28 and the separator 32 are indicated. Similarly, when the air electrode 30 is simply described, the air electrode 30 indicates the air electrode 30 provided on the other side in the stacking direction H (the side opposite to the first current collector plate 16 side).

  Conductive plates (not shown) may be provided between the fuel electrode 28 and the first current collector plate 16 and between the air electrode 30 and the second current collector plate 18. As shown in FIG. 2, each of the first current collector plate 16 and the second current collector plate 18 is provided with an electrical extraction portion 58 that protrudes from the opening of the extension portion 44 formed in a U-shape. Yes.

  Further, in this embodiment, each part is configured such that the connection area between the fuel electrode 28 and the first current collector plate 16 shown in FIG. 1 is larger than the connection area between the extension part 44 and the separator 32. Yes.

  When the fuel electrode 28 and the first current collector plate 16 are overlapped via the conductive plate, the connection area between the fuel electrode 28 and the first current collector plate 16 is the relationship between the fuel electrode 28 and the first current collector plate 16. This corresponds to the plane area of the conductive plate disposed between them. On the other hand, when the fuel electrode 28 and the first current collector plate 16 are directly overlapped, the connection area between the fuel electrode 28 and the first current collector plate 16 is the contact area between the fuel electrode 28 and the first current collector plate 16. It corresponds to. Further, when the extension portion 44 and the separator 32 are connected via the connection member 46, the connection area between the extension portion 44 and the separator 32 corresponds to the plane area of the connection member 46.

  In addition to the first current collector plate 16 described above, an insulating material 20 and a metal plate 22 are provided between the base portion 42 provided on the manifold 14 and the fuel electrode 28. The metal plate 22 is superposed on the first current collector plate 16 via the insulating material 20 from the base portion 42 side. The first current collecting plate 16 and the metal plate 22 are formed of a material having a higher coefficient of thermal expansion than the entire manifold 14 including the extending portion 44. The first current collector plate 16, the insulating material 20, and the metal plate 22 constitute an interposition part 60 that is interposed between the above-described fuel electrode 28 and the base part 42.

  In the fuel cell 10 according to the first embodiment, the first current collecting plate 16 and the metal plate 22 are heated when the fuel cell stack 12 generates heat. At this time, the first current collecting plate 16 and the metal plate 22 are thermally expanded in a state where the separator 32 is restrained with respect to the base portion 42 by the extending portion 44. And with this thermal expansion, the first current collector plate 16 is pressed against the fuel electrode 28, and the degree of adhesion between the fuel electrode 28 and the first current collector plate 16 increases.

  It should be noted that at least one of the first current collector plate 16 and the metal plate 22 is made of a material and a material so that the amount of thermal expansion in the stacking direction H is larger than that of the extending portion 44 when the fuel cell stack 12 generates heat. At least one of the volumes is set. As an example of this material, the first current collecting plate 16 is made of, for example, SUS310, the metal plate 22 is made of, for example, SUS316, and the manifold 14 including the extending portion 44 is made of, for example, ZMG232L (manufactured by Hitachi Metals). : Zr, La added to Fe-22Cr alloy).

  Next, the operation and effect of the first embodiment of the present invention will be described.

As described above in detail, according to the fuel cell 10 according to the first embodiment, the distal end portion 44A of the extending portion 44 extending from the base portion 42 to the fuel cell stack 12 side is fixed to the separator 32. The separator 32 is restrained with respect to the base portion 42 by the extending portion 44. Further, an interposition part 60 is interposed between the fuel electrode 28 and the base part 42, and the interposition part 60 is constituted by the metal first current collecting plate 16 and the metal plate 22 .

  Therefore, when the first current collector plate 16 and the metal plate 22 are heated during the heat generation of the fuel cell stack 12, the first current collector plate 16 and the separator 32 are restrained with respect to the base portion 42. The metal plate 22 is thermally expanded. The first current collecting plate 16 is pressed against the fuel electrode 28 along with the thermal expansion. Thereby, since the adhesion degree of the fuel electrode 28 and the 1st current collecting plate 16 can be raised, the electric power transmission loss between the fuel electrode 28 and the 1st current collecting plate 16 can be reduced.

  In addition, as described above, the first current collector plate 16 can be brought into close contact with the fuel electrode 28 without using a compression spring. Therefore, the size reduction can be achieved while suppressing the cost increase because the compression spring is unnecessary. Can do.

  In addition, according to the fuel cell 10, since the base portion 42 and the extension portion 44 are provided in the manifold 14, compared with the case where the base portion 42 and the extension portion 44 are provided separately from the manifold 14. The structure can be simplified.

  In addition, the interposition part 60 has a metal plate 22 in addition to the first current collector plate 16. Accordingly, when the fuel cell stack 12 generates heat, the metal plate 22 is heated and thermally expanded in addition to the first current collector plate 16 so that the first current collector plate 16 can be pressed against the fuel electrode 28. Therefore, since the first current collecting plate 16 that is generally expensive, such as being plated, can be made thinner by having the metal plate 22, the cost can be reduced.

  Further, both the first current collector plate 16 and the metal plate 22 are formed of a material having a higher coefficient of thermal expansion than the entire manifold 14 having the extending portion 44. Therefore, when the fuel cell stack 12 generates heat, the amount of thermal expansion of the first current collecting plate 16 and the metal plate 22 is larger than the amount of thermal expansion of the extending portion 44, so that the first current collecting plate 16 can be more securely attached. It can be pressed against the fuel electrode 28.

  Further, since the pair of the first wall portion 48 and the second wall portion 50 constituting the extension portion 44 are both provided on the side of the first current collector plate 16, It is possible to eliminate the necessity of providing a notch or a hole for avoiding the protruding portion 44. Thereby, since the size of the first current collector plate 16 can be ensured, the connection area between the fuel electrode 28 and the first current collector plate 16 can be ensured.

  In addition, the pair of first wall portions 48 of the extending portion 44 are respectively provided on both sides of the first current collector plate 16. The separator 32 can be restrained with respect to the base portion 42 on both sides of the plate 16. Therefore, when the fuel cell stack 12 generates heat, the pair of first wall portions 48 keeps the separator 32 from being bound to the base portion 42 on both sides of the first current collector plate 16. The first current collector plate 16 positioned between the first wall portions 48 can be pressed against the fuel electrode 28. Accordingly, for example, the degree of adhesion between the fuel electrode 28 and the first current collector plate 16 can be further increased as compared with the case where the separator 32 is restrained only by the first wall portion 48 on one side.

  Moreover, the whole extension part 44 which has a pair of 1st wall part 48 and the 2nd wall part 50 is formed along the peripheral edge 16A of the 1st current collecting plate 16 (refer FIG. 2). Accordingly, the extended portion 44 can ensure a long restraint length of the separator 32 along the peripheral edge 16 </ b> A of the first current collector plate 16. Thereby, since the 1st current collecting plate 16 can be pressed against the fuel electrode 28 over the circumferential direction of the 1st current collecting plate 16, the adhesion degree of the fuel electrode 28 and the 1st current collecting plate 16 is raised further. be able to.

  Further, since the connection area between the fuel electrode 28 and the first current collector plate 16 is larger than the connection area between the extension portion 44 and the separator 32, the fuel cell stack 12 extends from the fuel cell stack 12 during heat generation. More heat than the heat transmitted to the portion 44 can be transmitted from the fuel electrode 28 to the first current collector plate 16. As a result, the first current collecting plate 16 can be thermally expanded more efficiently, so that the first current collecting plate 16 can be pressed against the fuel electrode 28 with a higher load.

  Further, since the manifold 14 having the base portion 42 and the extending portion 44 and the interposition portion 60 including the first current collecting plate 16 and the metal plate 22 are provided only on one side of the fuel cell stack 12, the fuel electrode 28 is provided. The structure can be simplified while increasing the adhesion between the first current collector plate 16 and the first current collector plate 16.

  Next, a verification experiment performed on the first embodiment of the present invention will be described.

  In this verification experiment, as shown in FIG. 5, a fuel cell 310 according to a comparative example is used. The fuel cell 310 according to this comparative example is different from the fuel cell 10 according to the first embodiment described above in that the insulating material 20 and the metal plate 22 (see FIG. 1) are omitted, instead of the metal rod 312, the compression spring 314, And the support member 316 is provided.

  A hole 318 is formed in the center of the base portion 42, and the metal bar 312 is inserted into the hole 318. One end of the metal bar 312 is in contact with the first current collector plate 16, and the compression spring 314 is in contact with the other end of the metal bar 312. The support member 316 is fixed to both side portions of the hole 318 in the base portion 42, and a compression spring 314 is interposed between the support member 316 and the metal rod 312 in a compressed state.

  In the fuel cell 310 according to this comparative example, the configuration other than the above is the same as that of the fuel cell 10 according to the first embodiment described above. In the comparative example, the same reference numerals are used for the same configurations as those in the first embodiment.

FIG. 6 shows, as a result of the verification experiment performed on the first embodiment of the present invention, the fuel cell 10 according to the first embodiment (see FIG. 1) and the fuel cell 310 according to the comparative example (FIG. 5). The measurement results during power generation are shown for. The horizontal axis indicates current density [A / cm ² ], and the first vertical axis and the second vertical axis indicate voltage [V] and resistance [Ω], respectively.

  The graph G1 shows the voltage between the first current collector plate 16 and the second current collector plate 18 in the fuel cell 10 according to the first embodiment, and the graph G2 is the first current collector in the fuel cell 10 according to the first embodiment. The resistance between the current plate 16 and the second current collector 18 is shown. On the other hand, the graph G3 shows the voltage between the first current collector plate 16 and the second current collector plate 18 in the fuel cell 310 according to the comparative example, and the graph G4 shows the first current collector plate in the fuel cell 310 according to the comparative example. The resistance between 16 and the 2nd collector plate 18 is shown.

  As shown in FIG. 6, the graph G1 substantially overlaps the graph G3, and the graph G2 substantially overlaps the graph G4. From the above, it can be said that the fuel cell 10 according to the first embodiment has the same output performance as the fuel cell 310 according to the comparative example using the compression spring 314.

  Next, a modification of the first embodiment of the present invention will be described.

  In the first embodiment, the base portion 42 and the extending portion 44 shown in FIG. 1 are formed on the manifold 14, but may be formed on a member other than the manifold 14. Moreover, the base part 42 and the extension part 44 may be assembled together after being separated.

  In the first embodiment, the separator 32 is used as an example of the “electrode holding portion” in the present invention, but an electrode holding member other than the separator 32 may be used.

  Further, at one end in the stacking direction H of the plurality of fuel cells 24, a fuel electrode 28 is provided as an example of “electrodes provided at the ends in the stacking direction of the plurality of fuel cells” in the present invention. The first current collecting plate 16 was provided so as to overlap the fuel electrode 28. However, the air electrode 30 may be provided at one end in the stacking direction H of the plurality of fuel cells 24, and the first current collector plate 16 may be superimposed on the air electrode 30.

Moreover, although the interposition part 60 had the metal plate 22, it does not need to have the metal plate 22. FIG. Further, the interposition part 60 may have only the first current collector plate 16 . Moreover, when the interposition part 60 has only the 1st current collecting plate 16 (when the interposition part 60 is comprised by the 1st current collecting plate 16), at least the base part 42 among the manifolds 14 is formed with the insulating material. Also good.

  Further, the first current collector plate 16 and the metal plate 22 are both formed of a material having a higher thermal expansion coefficient than the entire manifold 14 having the extending portion 44. However, if the first current collector plate 16 can be pressed against the fuel electrode 28 during the heat generation of the fuel cell stack 12 as described above, either the first current collector plate 16 or the metal plate 22 is not connected to the manifold 14. It may be formed of the same material as at least the extension portion 44 or a material having a lower coefficient of thermal expansion than the extension portion 44. That is, for example, the metal plate 22 may be formed of SUS310, and the first current collector plate 16 and the manifold 14 may be formed of ZMG232L.

  Further, the first current collecting plate 16 and the metal plate 22 may be formed of the same material as at least the extending portion 44 of the manifold 14. In this case, the heat is most transmitted to the first current collecting plate 16 when the fuel cell stack 12 generates heat, so that the first current collecting plate 16 can be thermally expanded from the extending portion 44. As a result, the first current collector plate 16 can be pressed against the fuel electrode 28 along with this thermal expansion, so that the degree of adhesion between the fuel electrode 28 and the first current collector plate 16 can be increased.

  Moreover, although a pair of 1st wall part 48 and the 2nd wall part 50 were provided in the side of the 1st current collecting plate 16 (refer FIG. 2), places other than the side of the 1st current collecting plate 16 May be provided. Further, any one of the pair of first wall portions 48 may be omitted from the extending portion 44, and the second wall portion 50 shown in FIG. 2 may be omitted. In addition, as shown in FIG. 2, the pair of first wall portion 48 and second wall portion 50 are formed in a wall shape extending along the peripheral edge 16 </ b> A of the first current collector plate 16. For example, it may be formed in a shape other than the wall shape.

  Further, as shown in FIG. 1, the connection area between the fuel electrode 28 and the first current collector plate 16 is larger than the connection area between the extension portion 44 and the separator 32. However, if the first current collector plate 16 can be pressed against the fuel electrode 28 during the heat generation of the fuel cell stack 12 as described above, the connection area between the fuel electrode 28 and the first current collector plate 16 is extended. The connection area between the portion 44 and the separator 32 may be the same as or smaller than the connection area between the extension portion 44 and the separator 32.

  In the first embodiment, when the fuel cell stack 12 generates heat, the first current collector plate 16 and the metal plate 22 are thermally expanded, and the first current collector plate 16 is pressed against the fuel electrode 28 along with the thermal expansion. It was supposed to be. However, for example, the extension part 44 is formed to have a shorter dimension in the height direction than the interposition part 60, so that each part is elastically deformed, whereby the first current collector plate 16 is pressed against the fuel electrode 28 in advance. The first current collecting plate 16 may be configured to be pressed against the fuel electrode 28 before the heat generation of the fuel cell stack 12 is generated.

  In the first embodiment, the internal manifold type fuel cell stack 12 including the fuel conveyance path 34 and the air conveyance path 36 is used. However, the fuel cell 10 includes the fuel conveyance path 34 and the air conveyance path. A separator having 36 or the like may be provided outside the fuel cell stack 12.

  Moreover, the modification which can be combined among the said several modification in 1st embodiment may be implemented combining suitably.

[Second Embodiment]
Next, a second embodiment of the present invention will be described.

  The fuel cell 110 according to the second embodiment of the present invention shown in FIG. 3 is modified as follows with respect to the fuel cell 10 (see FIG. 1) according to the first embodiment of the present invention described above. Yes. In 2nd embodiment of this invention, the same code | symbol is used about the structure similar to the above-mentioned 1st embodiment.

  A restraining member 114 is added to the fuel cell 110 according to the second embodiment. The restraining member 114 is configured such that the fuel supply path 54 and the air supply path 56 are omitted from the manifold 14 described above. The restraining member 114 has the same configuration as that of the manifold 14 except that the fuel supply path 54 and the air supply path 56 are omitted, and includes a flat plate-like base portion 142 and a wall-like extension portion 144. ing. The base portion 142 and the extension portion 144 have the same configuration as the base portion 42 and the extension portion 44 provided in the manifold 14 described above.

  The base portion 142 is provided apart from the air electrode 30 provided on the other side in the stacking direction H in the extending direction of the stacking direction H. Further, the extending portion 144 extends from the base portion 142 to the fuel cell stack 12 side. The distal end portion 144A of the extending portion 144 is fixed to a separator 32 provided on the other side in the stacking direction H via a connecting member 146 such as ceramic glass.

  In addition to the second current collector plate 18 described above, the insulating material 120 and the metal plate 122 are interposed between the air electrode 30 provided on the other side in the stacking direction H and the base portion 142 provided on the restraining member 114. Is provided. The metal plate 122 is superimposed on the second current collector plate 18 from the base portion 142 side through the insulating material 120.

  As an example, the second current collecting plate 18 and the metal plate 122 are made of the same material as the first current collecting plate 16 and the metal plate 22 described above, and are formed from the entire restraining member 114 including the extending portion 144. Is also made of a material having a high coefficient of thermal expansion. The second current collecting plate 18, the insulating material 120, and the metal plate 122 constitute an interposition part 160 interposed between the air electrode 30 and the base part 142 described above.

  In the fuel cell 110 according to the second embodiment, the first current collector plate 16, the second current collector plate 18, and the metal plates 22 and 122 are heated when the fuel cell stack 12 generates heat. At this time, the separator 32 provided on one side in the stacking direction H is restrained with respect to the base portion 42 by the extending portion 44, and the separator 32 provided on the other side in the stacking direction H is extended by the extending portion 144. The base portion 142 is restrained. Further, the first current collector plate 16, the second current collector plate 18, and the metal plates 22 and 122 are thermally expanded in a state where the separators 32 are restrained in this way.

  As the first current collector plate 16 and the metal plate 22 are thermally expanded, the first current collector plate 16 is pressed against the fuel electrode 28, and the degree of adhesion between the fuel electrode 28 and the first current collector plate 16 is increased. Similarly, the second current collecting plate 18 is pressed against the air electrode 30 as the second current collecting plate 18 and the metal plate 122 are thermally expanded, and the degree of adhesion between the air electrode 30 and the second current collecting plate 18 is increased.

  Note that at least one of the second current collecting plate 18 and the metal plate 122 described above has a larger amount of thermal expansion in the stacking direction H than the extending portion 144 of the restraining member 114 when the fuel cell stack 12 generates heat. At least one of the material and the volume is set.

  Thus, according to the second embodiment, the base portions 42 and 142, the extension portions 44 and 144, and the interposition portions 60 and 160 are provided on both sides of the fuel cell stack 12, respectively. 28 and the first current collector plate 16 and the close contact between the air electrode 30 and the second current collector plate 18 can be increased. Thereby, the power transmission loss between the fuel electrode 28 and the first current collector plate 16 and the power transmission loss between the air electrode 30 and the second current collector plate 18 can be reduced.

  Further, as described above, the first current collector plate 16 can be brought into close contact with the fuel electrode 28 without using a compression spring, and the second current collector plate 18 can be brought into close contact with the air electrode 30. Thereby, since the compression spring is unnecessary, it is possible to reduce the size while suppressing an increase in cost.

  In addition, in this 2nd embodiment, about the structure similar to the above-mentioned 1st embodiment, there can exist an effect similar to 1st embodiment.

  In the second embodiment, the base portion 142 and the extending portion 144 provided on the restraining member 114 may be assembled separately after being separated.

Moreover, although the interposition part 160 had the metal plate 122, it does not need to have the metal plate 122. FIG. Further, the interposition part 160 may have only the second current collector plate 18 . Moreover, when the interposition part 160 has only the 2nd current collector plate 18 (when the interposition part 160 is comprised with the 2nd current collector plate 18), at least the base part 142 among the restraint members 114 is formed with an insulating material. May be.

  Further, the second current collector plate 18 and the metal plate 122 are both made of a material having a higher coefficient of thermal expansion than the entire restraining member 114 having the extending portion 144. However, as described above, if the second current collector plate 18 can be pressed against the air electrode 30 during power generation heat generation of the fuel cell stack 12, either the second current collector plate 18 or the metal plate 122 may be the restraining member 114. Of these, at least the extension portion 144 may be formed of the same material or a material having a lower coefficient of thermal expansion than the extension portion 144.

  Further, in the present embodiment, the second current collector plate 18 and the metal plate 122 are thermally expanded during the heat generation of the fuel cell stack 12, and the second current collector plate 18 is pressed against the air electrode 30 along with the thermal expansion. It was like that. However, for example, the extension portion 144 is formed to have a shorter dimension in the height direction than the interposition portion 160, so that each portion is elastically deformed, whereby the second current collector plate 18 is pressed against the air electrode 30 in advance. The second current collecting plate 18 may be configured to be pressed against the air electrode 30 before the heat generation of the fuel cell stack 12 is generated.

  In the second embodiment, the same modification as in the first embodiment may be adopted for the same configuration as in the first embodiment described above.

  Moreover, the modification which can be combined among the said several modification in 2nd embodiment may be implemented combining suitably.

[Third embodiment]
Next, a third embodiment of the present invention will be described.

  The fuel cell 210 according to the third embodiment of the present invention shown in FIG. 4 is configured as follows with respect to the fuel cell 110 (see FIG. 3) according to the second embodiment of the present invention described above. Yes. In 3rd embodiment of this invention, the same code | symbol is used about the structure similar to the above-mentioned 2nd embodiment.

  In the fuel cell 210 according to the third embodiment, the distal end portion 144A of the extending portion 144 provided in the restraining member 114 is connected to the distal end portion 44A of the extending portion 44 provided in the manifold 14 via the connecting member 46. It is fixed. Further, the extending portion 144 is separated from the fuel cell stack 12.

  In the fuel cell 210 according to the third embodiment, the fuel electrode 28 provided at one end in the stacking direction H of the plurality of fuel cells 24 is “one of the stacking directions in the plurality of fuel cells” according to the present invention. The air electrode 30 provided on the other side in the stacking direction H is an example of the “first electrode provided at the end on the side”, and the “electrode on the other side in the stacking direction in the plurality of fuel cells” in the present invention. It is an example of a “second electrode provided”.

  The base part 42 and the extension part 44 provided in the manifold 14 are examples of the “first base part” and the “first extension part” in the present invention, and the base part 142 provided in the restraining member 114. The extension portion 144 is an example of the “second base portion” and the “second extension portion” in the present invention. Further, the interposition part 60 provided on one side of the fuel cell stack 12 is an example of the “first interposition part” in the present invention, and the interposition part 160 provided on the other side of the fuel cell stack 12 is the present invention. Is an example of a “second intervening portion”.

According to the fuel cell 210 according to the third embodiment, the distal end portion 44A of the extending portion 44 that extends from the one base portion 42 to the fuel cell stack 12 side is provided on one side in the stacking direction H. The separator 32 is fixed to the separator 32 holding the fuel electrode 28, and the separator 32 is restrained with respect to the base portion 42 by the extending portion 44. Further, an interposition part 60 is interposed between the fuel electrode 28 and the base part 42, and the interposition part 60 is constituted by the metal first current collecting plate 16 and the metal plate 22 .

Accordingly, when the first current collecting plate 16 and the metal plate 22 are heated during the power generation heat generation of the fuel cell stack 12, the separators 32 are restrained with respect to the base portion 42, and the intervening portion 60 is configured . The current collector plate 16 and the metal plate 22 are thermally expanded. The first current collecting plate 16 is pressed against the fuel electrode 28 along with the thermal expansion. Thereby, since the adhesion degree of the fuel electrode 28 and the 1st current collecting plate 16 can be raised, the electric power transmission loss between the fuel electrode 28 and the 1st current collecting plate 16 can be reduced.

Furthermore, the distal end portion 144A of the extending portion 144 extending from the other base portion 142 to the fuel cell stack 12 side is fixed to one extending portion 44, and the other extending portion 144 allows the other end portion 144A to be The base portion 142 is restrained with respect to the one extending portion 44. Further, an interposition part 160 is interposed between the air electrode 30 and the base part 142, and the interposition part 160 is constituted by a metal second current collector plate 18 and a metal plate 122 .

Therefore, when the second current collecting plate 18 and the metal plate 122 are heated during the power generation heat generation of the fuel cell stack 12, the other base portion 142 is constrained with respect to the one extending portion 44 and is interposed. The second current collecting plate 18 and the metal plate 122 constituting the part 160 are thermally expanded. In association with this thermal expansion, the fuel electrode 28 and the air electrode 30 that overlap each other in the plurality of fuel cells 24 are pressed against each other, and the second current collector plate 18 is pressed against the air electrode 30.

  As a result, the degree of adhesion between the overlapping fuel electrode 28 and air electrode 30 can be increased, and the degree of adhesion between the air electrode 30 and the second current collector plate 18 can be increased. As a result, the power transmission loss between the overlapping fuel electrode 28 and the air electrode 30 and the power transmission loss between the air electrode 30 and the second current collector plate 18 can be reduced.

  As described above, according to the third embodiment, not only can the first current collecting plate 16 be brought into close contact with the fuel electrode 28, but also the second current collecting plate 18 can be brought into close contact with the air electrode 30. The fuel electrode 28 and the air electrode 30 that overlap each other in the fuel cell 24 can be brought into close contact with each other.

  In addition, as described above, since each member can be brought into close contact without using a compression spring, it is possible to reduce the size while suppressing an increase in cost because the compression spring is unnecessary.

  In addition, in this 3rd embodiment, there can exist an effect similar to 1st and 2nd embodiment about the structure similar to the above-mentioned 1st and 2nd embodiment.

  In the third embodiment, the distal end portion 144A of the extending portion 144 provided on the restraining member 114 may be fixed to the base portion 42 instead of the extending portion 44. It may be fixed to both of the protruding portions 44.

  In the third embodiment, the same modification as in the first and second embodiments may be adopted for the same configuration as in the first and second embodiments described above.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above, and it is needless to say that various modifications can be made without departing from the spirit of the present invention. is there.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell, 12 ... Fuel cell stack, 14 ... Manifold, 16 ... First collector plate (an example of a collector plate), 16A ... Periphery, 18 ... Second collector plate, 20 ... Insulating material, 22 ... Metal Plate, 24 ... Fuel cell, 26 ... Electrolyte layer, 28 ... Fuel electrode (an example of an electrode provided at the end in the stacking direction of a plurality of fuel cells and an example of the first electrode), 30 ... Air electrode (first electrode) An example of two electrodes), 32... Separator (an example of an electrode holding portion), 34... A fuel conveyance path, 36... An air conveyance path, 38. ), 44... Extension portion (an example of the first extension portion), 44 A... Tip portion, 46 .. connection member, 48... First wall portion, 50. ... Air supply path, 58 ... Electric extraction part, 60 ... Interposition part (an example of a first interposition part), 110 ... Fuel electricity , 114 ... restraining member, 120 ... insulating material, 122 ... metal plate, 142 ... base part (an example of the second base part), 144 ... extension part (an example of the second extension part), 144A ... tip part, 146 ... connecting member, 160 ... interposition part (an example of the second interposition part), 210 ... fuel cell

Claims (11)

A fuel cell stack having a plurality of stacked fuel cells in solid oxide form;
A base portion provided apart from an electrode provided at an end portion in the stacking direction of the plurality of fuel cells in the extending direction of the stacking direction;
An extension part extending from the base part to the fuel cell stack side, and a tip part fixed to an electrode holding part for holding the electrode in the fuel cell stack;
It is constituted by a metal current collecting plate superimposed on the electrode , or is constituted by the current collecting plate, an insulating material, and a metal plate superimposed on the current collecting plate via the insulating material. And the thermal expansion of the current collector plate or the thermal expansion of the current collector plate and the metal plate during the heat generation of the fuel cell stack interposed between the electrode and the base portion An interposition part where the current collector plate is pressed against the electrode ;
A fuel cell. A manifold for supplying fuel gas and air gas to the plurality of fuel cells;
The manifold includes the base portion and the extension portion.
The fuel cell according to claim 1. The interposition part is configured by the current collector plate, the insulating material, and the metal plate superimposed on the current collector plate via the insulating material ,
The fuel cell according to claim 1 or 2. At least one of the current collector plate and the metal plate is formed of a material having a higher coefficient of thermal expansion than the extending portion.
The fuel cell according to claim 3. The extending portion is provided on a side of the current collector plate,
The fuel cell according to any one of claims 1 to 4. The extension part is provided on the side of both sides of the current collector plate,
The fuel cell according to any one of claims 1 to 5. The extension part is formed along the periphery of the current collector plate,
The fuel cell according to any one of claims 1 to 6. The connection area between the electrode and the current collector plate is larger than the connection area between the extension part and the electrode holding part,
The fuel cell according to any one of claims 1 to 7. The base part, the extension part, and the interposition part are provided only on one side of the fuel cell stack,
The fuel cell according to any one of claims 1 to 8. The base part, the extension part, and the interposition part are provided on both sides of the fuel cell stack,
The fuel cell according to any one of claims 1 to 9. A fuel cell stack having a plurality of stacked fuel cells in solid oxide form;
A first base portion provided apart from the first electrode provided at one end in the stacking direction of the plurality of fuel cells in the extending direction of the stacking direction;
A second base portion provided apart from the second electrode provided at the end portion on the other side in the stacking direction of the plurality of fuel cells, in the extending direction of the stacking direction;
A first extension portion extending from the first base portion toward the fuel cell stack side, and a tip portion fixed to an electrode holding portion for holding the first electrode in the fuel cell stack;
A second extending portion extending from the second base portion toward the fuel cell stack, and having a tip portion fixed to at least one of the first base portion and the first extending portion;
It is constituted by a metal first current collecting plate superimposed on the first electrode , or the first current collecting plate, the first insulating material, and the first current collecting plate on the first insulating material And the first current collector plate is interposed between the first electrode and the first base portion , and when the fuel cell stack generates heat, the first current collector plate. Or a first interposition part in which the first current collector plate is pressed against the first electrode in accordance with the thermal expansion of the first current collector plate and the first metal plate ;
It is comprised by the metal 2nd current collector plate piled up by said 2nd electrode , or said 2nd current collector plate, a 2nd insulating material, and said 2nd current collector plate to said 2nd insulating material And the second current collector plate is interposed between the second electrode and the second base portion , and when generating heat from the fuel cell stack, the second current collector plate. Or a second interposition part in which the second current collector plate is pressed against the second electrode in accordance with the thermal expansion of the second current collector plate and the second metal plate ,
A fuel cell.

Images