JP5151194B2 - Fuel cell stack structure - Google Patents

Description

    The present invention relates to a fuel cell stack structure in which solid oxide fuel cells are stacked.

  Conventionally, as the fuel cell stack structure as described above, for example, a fuel cell in which flat single cells are stacked so that the same type of electrodes face each other, and a space formed between the same type of electrodes is used as a gas flow path There is a stack structure, and by arranging the current collector in the gas flow path, all the single cells are electrically connected in parallel, or the single cells that are insulated from each other are electrically connected by an external conductor. There is something.

In addition to the fuel cell stack structure described above, hollow disk-type cells having all of the outer surfaces as air electrodes and all of the inner surfaces as fuel electrodes are stacked, and different types of layers are used in each of the stacked portions. There is a fuel cell stack structure in which electrodes are in electrical contact.
Japanese Patent Application No. 7-214216 JP 2002-50390 A JP 2002-8681 A

  However, in the fuel cell stack structure described above, in the fuel cell stack structure in which the current collector is arranged in the gas flow path formed between the same type of electrodes, all the flat single cells are connected in parallel. On the other hand, a fuel cell stack structure having a configuration in which a single cell that is insulatively connected to each other is electrically connected to each other by an external conductor using a space formed between the same type of electrodes as a gas flow path Then, although either serial connection or parallel connection can be arbitrarily selected, for the convenience of carrying out electrical connection with an external conductor, when the conductor wire diameter is increased to correspond to a large current, In the case where packing is performed at a high density by narrowing the stacking interval, there is a problem that it is difficult to bring the conductor into contact with the single cell.

  In addition, in a fuel cell stack structure in which hollow disk-type cells are stacked and electrodes are arranged at the connection portions between the cells, if the electrodes are made into a thin film, the electrical resistance increases (in the case of series connection). In particular, the electrical resistance increases, and if the electrodes are thickened to avoid this, it is difficult to realize the overall miniaturization. It was an issue.

  The present invention has been made paying attention to the above-described conventional problems, and can be selected from series connection and parallel connection of single cells, that is, both high voltage specifications and large current specifications can be supported. It is an object to provide a fuel cell stack structure that is small and has high output.

The present invention, have a introduction hole and the discharge hole of one gas of fuel gas and air into the central portion with holding the single cell and two cell plates ing a material having electron conductivity A stack structure formed by laminating a plurality of cell units formed by joining the peripheral portions of each of the two through a current collector, and a flow path space of one gas formed between both cell plates of the cell unit. The same type electrodes of each single cell are opposed to each other, and the inward electrodes of these opposed single cells and the cell plate of the cell unit are electrically connected. The configuration of the fuel cell stack structure is used as a means for solving the above-described conventional problems.

  In the fuel cell stack structure of the present invention, in the overlapping cell plates, the same kind of electrodes of the single cells are made to face each other, so that a separator becomes unnecessary, and in addition, current collectors and connections arranged inside and outside between the cell plates By making electrical connection at the terminals, an increase in electrical resistance is suppressed, and as a result, miniaturization is achieved while maintaining high output.

  In addition, by selecting the contact portions of the current collectors and connection terminals arranged inside and outside between the overlapping cell plates, it is possible to easily cope with both series connection and parallel connection, and a high voltage type fuel cell Both the stack structure and the high-current type fuel cell stack structure can be easily designed.

  According to the fuel cell stack structure of the present invention, since it has the above-described configuration, it can be compatible with both high voltage specifications and large current specifications, and can achieve downsizing and high output. It has a very good effect of being possible.

  In the fuel cell stack structure of the present invention, the cell plate is made of a metal, an alloy, a material having electronic conductivity such as a conductive oxide, and as a single cell held by the cell plate, for example, In addition, it is possible to adopt one arranged like a ring-shaped single cell in a continuous manner on the cell plate or one divided like a fan-shaped single cell arranged on the cell plate.

  Further, in the fuel cell stack structure of the present invention, the cell unit is provided with a gas flow path in the stacking direction of the cell unit in the central portion, and has conductivity to supply one gas to the flow path space between both cell plates. The central flow path component can be arranged, and the inward electrodes of the single cells facing each other and the central flow path component can be electrically connected.

  In this case, the plurality of cell units can be stacked by bringing the central flow path components into contact with each other, or the cell plates can be stacked in contact with each other, and the central flow path component of one cell unit and the other. The cell plates of the cell unit can be brought into contact and stacked.

  Here, the electrical connection between each inward electrode of the single cell and the cell plate of the cell unit is performed by arranging the inward electrode of the single cell directly on the cell plate or by arranging in the flow path space of the cell unit. For example, when the cell units are stacked, the cell plate can be used as the electrical connection terminal portion of the inward electrode.

  On the other hand, the electrical connection between each inward electrode of the single cell and the central flow channel component can be performed by joining the central flow channel component to the cell plate. It can be used as the electrical connection terminal part of the orientation electrode, and as such, the increase in electrical resistance can be suppressed by using the central flow path component as the connection terminal part, particularly when connecting in parallel. Therefore, high output can be realized.

  Furthermore, in the fuel cell stack structure of the present invention, it is possible to adopt a configuration in which a single cell prepared in advance is joined to a cell plate, and a single cell arrangement portion of the cell plate of the cell unit is used as a porous support portion. A configuration in which a single cell is formed in the porous support portion can be adopted. With this configuration, in addition to realizing a smaller size and higher output, an improvement in rapid startability can be achieved. .

  The porous support portion is a communicating portion for supplying one of the fuel gas and air introduced into the flow path space between the two cell plates to the single cell, and is made of a metal or alloy porous support. In the case of forming a single cell on the part, the porous support part is not damaged.For example, it is necessary to adopt an oxidation method, a sputtering method, an electron beam method, an aerosol deposition method, a sintering method, Although a method such as a ligation method can be employed, it is not limited to these methods.

  Furthermore, in the fuel cell stack structure of the present invention, a configuration in which a plurality of stacked cell units are electrically connected by a cell plate of the cell unit, a central flow path component, and a current collector disposed between the cell units. Specifically, as the current collector that is disposed between the cell units and contacts the outward electrode of the single cell, a bag-shaped one that covers the cell unit can be used.

  At this time, in order to prevent the bag-shaped current collector, which is placed on the cell unit and brought into contact with the outward electrode, from conducting with the portion around the outward electrode on the cell plate of the cell unit, the bag-shaped current collector is used. An insulating member is disposed between the body and the cell plate, or an insulating film is formed on at least one surface of the current collector and the cell plate. The insulation method is not limited.

  Therefore, in the fuel cell stack structure of the present invention, for example, when a plurality of cell units 1, 2, 3... N are electrically connected in series, the cell unit 1 is covered with an outward electrode. The contacted bag-shaped current collector is connected to the cell plate of the adjacent cell unit 2, and then the bag-shaped current collector brought into contact with the outward electrode of the cell unit 2 is connected to the adjacent cell unit 3. In the same manner, the bag-shaped current collector that is in contact with the outward electrode is connected to the cell plate of the adjacent cell unit N.

  In this case, it is necessary to laminate the overlapping portions of each cell unit in an electrically insulated state, and also to make the adjacent bag-shaped current collectors electrically insulated from each other. In order to join each other in an electrically insulated state, a method of joining with an insulating adhesive or a glass sealing material can be adopted, and a part to be joined or laminated via an insulating member such as alumina ( A method of manufacturing and joining the central flow path component) itself with an insulating material can be adopted, but the method (structure) is not particularly limited.

  Also, in order to electrically insulate adjacent bag-shaped current collectors from each other, an insulating layer (such as a coating or sheet of an insulating material) is provided on the surface of the current collector that does not contact the outward electrode. It is desirable to arrange. This is for ensuring the pressure contact force with respect to an outward electrode by making it adjoin so that adjacent bag-shaped collectors may mutually press. Note that when it is not necessary to press the bag-shaped current collectors against each other, it is not necessary to dispose the insulating layer described above.

  On the other hand, in the fuel cell stack structure of the present invention, for example, when a plurality of cell units 1, 2, 3,... N are electrically connected in parallel, the cell units 1, 2, 3,. ..Both-shaped current collectors that are in contact with the N outward electrodes are electrically connected to each other, and the overlapping portions of each cell unit are stacked in an electrically conductive state.

  As described above, when a configuration in which a plurality of stacked cell units are electrically connected by the cell plate of the cell unit, the central flow path component, and the current collector disposed between the cell units is employed, the electrical resistance increases. In addition, series output and parallel connection can be easily selected simply by changing the contact part of the cell plate and the central flow path component to the adjacent current collector. As a result, the design is easy in both the high voltage type and the large current type specifications.

  Furthermore, in the fuel cell stack structure according to the present invention, a plurality of stacked cell units can be electrically connected at the peripheral edge of the cell unit. In this way, when electrical connection is made at the peripheral part of the cell unit, the cross-sectional area of the current path can be secured larger on the peripheral part side than on the central part side of the cell unit, thereby further increasing the electrical resistance. It can be suppressed to a small extent.

  Specifically, a notch is provided in the peripheral portion of the bag-shaped current collector that contacts the outward electrode, and the notch of the adjacent bag-shaped current collector is shifted so that the cell plate portion exposed from the notch and the bag-shaped current collector This can be implemented by connecting the current collector.

  EXAMPLES Hereinafter, although an Example demonstrates this invention still in detail, specifications, such as a dimension and a material of each component, are not limited to a following example.

[Example 1]
1 to 6 show an embodiment of a fuel cell stack structure according to the present invention. As shown in FIGS. 2 and 3, this fuel cell stack structure has a fuel electrode support having a circular ring shape. A plurality of cell plates 1 formed by joining supports 2 and 3 to the inner peripheral edge and the outer peripheral edge of the single cell 10 of the mold, respectively, and as shown in FIG. While sandwiching the central flow path component 6 between the inner peripheral support members 2 and 2 of the two cell plates 1 and 1 disposed so that the electrodes 11 and 11 face each other, the outer periphery of the outer support members 3 and 3 A set of cell units U is formed by joining the peripheral edges.

  In this case, the space bound between the two cell plates 1 and 1 in the cell unit U is formed as the fuel gas flow path 4, and the inner peripheral side support bodies 2 and 2 of the cell plates 1 and 1 Is formed with a fuel gas introduction hole 2a and a fuel gas discharge hole 2c. On the other hand, as shown in FIG. A gas supply channel 6a in the stacking direction that communicates, a gas distribution channel 6b in the horizontal direction that communicates with the gas supply channel 6a and distributes the fuel gas to the fuel gas channel 4, and the inner peripheral support 2 A fuel gas discharge channel 6c communicating with the fuel gas discharge hole 2c is formed.

  As shown in FIG. 1, an air gas flow path 5 is formed between the overlapping cell units U and U. The fuel gas flow path 4 between the two cell plates 1 and 1 has a circular ring. Current collector 7 is disposed in the air gas flow path 5 between the cell units U, U is disposed in a bag shape current collector 8 that can cover the cell unit U, The inner peripheral support bodies 2 and 2 of the cell plates 1 and 1 in the cell unit U are used as connection terminals for the single cell 10.

  In this example, a fuel electrode supporting cell (fuel electrode 11: Ni-SDC, electrolyte 12: SDC, air electrode 13: SSC) having an outer diameter of 150 mmφ and an inner diameter of 50 mmφ was used as a single cell 10 having a ring shape. Here, the SSC which is the air electrode 13 is formed with an outer diameter of 135 mmφ−an inner diameter of 65 mmφ, and the region of the outer peripheral portion 135 to 150 mmφ where the SSC is not formed is connected to the outer peripheral side support 3 described later. Similarly, the region of the inner peripheral portion 50 to 65 mmφ where the SSC is not formed is the bonding surface with the inner support 2 described later.

  Further, as the inner support 2, SUS430 having an outer diameter of 60 mmφ and a thickness of 100 μm is used, and this is joined to the inner peripheral edge of the electrolyte 12 in the ring-shaped single cell 10 by a glass sealing material. As the side support 3, SUS430 having an outer diameter of 200 mmφ−inner diameter of 140 mmφ and a thickness of 100 μm was used, and this was joined to the outer peripheral edge of the electrolyte 12 in the ring-shaped single cell 10 with a glass sealing material. A cell plate 1 was formed.

  Then, the two cell plates 1 and 1 are arranged so that the fuel electrodes 11 and 11 of the single cell 10 face each other, and a gas supply channel 6a, a gas distribution channel 6b, and a fuel gas discharge channel 6c are provided. While holding the central flow path component 6 made of SUS430 between the inner peripheral supports 2 and 2, the outer peripheral edges of the outer peripheral supports 3 and 3 of the two cell plates 1 and 1 are joined to each other. A set of cell units U was obtained.

  Further, the current collectors 7 and 8 arranged inside and outside the cell unit U are made of Inconel 600, and the cell unit U is positioned in the fuel gas flow path 4 between the two cell plates 1 and 1. The fuel electrodes 11, 11 of the single cell 10 are electrically connected to each other via the current collector 7, and the current collector 7 is connected to the cell plate 1 (inner periphery side support 2, outer periphery side support 3) and The central flow path component 6 was brought into contact. On the other hand, the current collector 8 having a bag shape that covers the cell unit U, that is, the current collector 8 positioned in the air gas flow path 5 is brought into contact with the air electrode 13 of the single cell 10 exposed to the outside of the cell unit U. It was.

  When the cell units U thus obtained are stacked via the current collector 8, the inner peripheral side supports 2 and 2 of the overlapping cell units U are joined together by a ceramic adhesive 9A having sealing properties and insulating properties. The bag-shaped current collector 8 is electrically connected to the inner peripheral side support 2 of the adjacent cell unit 1 on the upper side of FIG. Here, in order to avoid electrical contact between the adjacent bag-shaped current collectors 8, 8, the respective contact surfaces of the current collectors 8, 8 are covered with an insulating material 9 </ b> B to be electrically insulated. To do.

  Further, a bag-shaped current collector 8 placed on the cell unit U and brought into contact with the air electrode 13 is a portion around the air electrode 13 in the cell plate 1 of the cell unit U, that is, the inner peripheral support 2 and In order to prevent conduction with the outer peripheral side support body 3, an insulating coating 9C is formed on the inner peripheral side support body 2 and the outer peripheral side support body 3, and thereafter the bag is brought into contact with the air electrode 13 in the same manner. When the current collector 8 having a shape is connected to the cell plate 1 of the adjacent cell unit U, a fuel cell stack structure in which a plurality of cell units U are electrically connected in series is obtained.

  That is, in the fuel cell stack structure described above, as shown in FIG. 6, the inner peripheral support 2 and the central flow path component 6 in the cell plate 1 of the cell unit U can be used as connection terminals of the cell unit U. It becomes.

[Example 2]
7 to 12 show other embodiments of the fuel cell stack structure of the present invention. As shown in FIG. 7, in the fuel cell stack structure in this example, the same central flow path component 6 as in Example 1 was used. Further, as the cell plate 21, SUS430 having an outer diameter of 120 mmφ and a thickness of 100 μm is used, and this cell plate 21 is partially porous as shown in FIG. After the fuel electrode 31 (Ni-YSZ) is formed on the fan-shaped portion 21a by sputtering, an electrolyte 32 (YSZ) is formed by sputtering as shown in FIG. The cell plate 21 holding the single cell 30 was obtained by forming the air electrode 33 (LSM) in a pattern by sputtering.

  Then, the two cell plates 21 and 21 and the central flow path component 6 were joined in the same manner as in the previous example to obtain a set of cell units U1. In this embodiment, the fuel electrode 31 of the single cell 30 is formed directly on the fan-shaped portion 21a of the cell plate 21, so that the fuel electrode 31 does not require a current collector, and the cell plate 21 and the central flow path. It is in a state of being electrically connected to the component 6. On the other hand, the current collector 28 in contact with the air electrode 33 of the single cell 30 has a bag shape as in the first embodiment, and is disposed at the same position and in the same shape as the electrolyte 32 as shown in FIG. It is.

  When the cell units U1 thus obtained are stacked via the current collector 28, the central flow path component 6 holding portions of the overlapping cell units U1 are joined together by a ceramic adhesive 29A having a sealing property and an insulating property. In this case, as shown in FIG. 11, notches 28a are provided in the outer peripheral edge of the bag-shaped current collector 28, and the notches 28a of the bag-shaped current collectors 28 adjacent to each other are shifted in the circumferential direction so that these Each cell unit U1 is laminated so that the outer peripheral edge portion of the cell plate 21 exposed from the notch 28a and the bag-shaped current collector 28 are connected.

  Here, in order to avoid electrical contact between the adjacent bag-shaped current collectors 28, 28, the respective contact surfaces of the current collectors 28, 28 are covered with an insulating material 29B to be electrically insulated. Thereafter, similarly, when the bag-shaped current collector 28 brought into contact with the air electrode 33 is connected to the outer peripheral edge portion of the cell plate 21 of the adjacent cell unit U1, a plurality of cell units U1 are electrically connected in series. The obtained fuel cell stack structure is obtained. In this embodiment, since the electrolyte 32 is formed on the cell plate 21, the current collector 28 and the cell plate 21 are not in electrical contact.

  That is, also in the fuel cell stack structure in this embodiment, as shown in FIG. 12, the cell plate 21 of the cell unit U1 can be used as the connection terminal of the cell unit U1.

[Example 3]
13 and 14 show still another embodiment of the fuel cell stack structure of the present invention. As shown in FIG. 13, in the fuel cell stack structure in this embodiment, a notch 28a is formed at the outer peripheral edge. A parallel stack unit SU1 was obtained by connecting three sets of cell units U1 in parallel using a current collector 28 similar to the bag-shaped current collector 28 of Example 2 having the above. At this time, in order to connect the cell units U1 in parallel, the adjacent current collectors 28, 28 are electrically connected, and similarly, the central flow path component 6 holding portions of the cell units U1 that overlap each other are also connected. In addition, since it is necessary to be electrically connected, sealing and conductive bonding are performed instead of sealing and insulating bonding.

  On the other hand, three sets of cell units U1 are newly connected in parallel to form one set of parallel stack units SU2, and using the same current collector 28 as the bag-shaped current collector 28 of the second embodiment, The parallel stack units SU1, SU2 are electrically connected in series. At this time, in order to avoid electrical contact between the adjacent bag-shaped current collectors 28, 28, the respective contact surfaces of the current collectors 28, 28 are covered with an insulating material 29B to be electrically insulated. In addition, the central flow path component 6 holding portions of the parallel stack units SU1 and SU2 that overlap each other are joined together by a ceramic adhesive 29A having a sealing property and an insulating property, and thereafter the electrical connection is repeated in the same manner. As shown in FIG. 15, a fuel cell stack in which a plurality of cell stacks U1 are electrically connected in parallel, and two sets of parallel stack units SU1, SU2 are electrically connected in series. A structure is obtained.

  That is, also in the fuel cell stack structure in this embodiment, the cell plate 21 of the cell unit U1 can be used as the connection terminal of the cell unit U1.

1 is a cross-sectional explanatory view of a fuel cell stack structure according to an embodiment of the present invention. Example 1 FIG. 2 is an overall perspective explanatory view of a cell plate of the fuel cell stack structure in FIG. 1. Example 1 FIG. 2 is an exploded perspective view of a cell unit of the fuel cell stack structure in FIG. 1. Example 1 FIG. 2 is a cross-sectional explanatory view of a cell unit of the fuel cell stack structure in FIG. 1. Example 1 FIG. 2 is an explanatory plan view (a), an ab line cross-sectional explanatory view (b), and a cd line cross-sectional explanatory view (c) of the central flow path component of the fuel cell stack structure in FIG. 1. Example 1 FIG. 2 is a circuit explanatory diagram of the fuel cell stack structure in FIG. 1. Example 1 FIG. 4 is a cross-sectional explanatory view of a fuel cell stack structure according to another embodiment of the present invention. (Example 2) FIG. 8 is an explanatory plan view of a cell plate of the fuel cell stack structure in FIG. 7. (Example 2) It is a plane explanatory view of the electrolyte which constitutes the single cell of the fuel cell stack structure in FIG. (Example 2) It is a plane explanatory view of the current collector of the fuel cell stack structure in FIG. (Example 2) It is explanatory drawing of the lamination | stacking point of the cell board of FIG. 8, and the electrical power collector of FIG. (Example 2) It is a circuit explanatory drawing of the fuel cell stack structure in FIG. (Example 2) FIG. 6 is a cross-sectional explanatory view of a fuel cell stack structure according to still another embodiment of the present invention. (Example 3) FIG. 12 is a circuit explanatory diagram of the fuel cell stack structure in FIG. 11. (Example 3)

Explanation of symbols

1,21 cell plate
4,24 Fuel gas channel (channel space)
6 Central flow path parts 6a, 6b Gas supply / discharge holes 8, 28 Current collector 28a Notch of current collector (electrical connection part at the periphery of the cell unit)
10,30 Single cell 11,31 Fuel electrode 12,32 Electrolyte 13,33 Air electrode 21a Fan-shaped part (porous support part)
U, U1 cell unit

Claims (7)

Have a introduction hole and the discharge hole of one gas of fuel gas and air into the central portion with holding the single cell, and the periphery of the two cell plates ing a material having electron conductivity A stack structure formed by stacking a plurality of cell units formed by joining together via a current collector,
The same type of electrodes of each single cell are opposed to each other across the flow path space of one gas formed between the two cell plates of the cell unit, and each inward electrode of these opposing single cells and the cell of the cell unit A fuel cell stack structure characterized in that the plate is electrically connected. In the central part of the cell unit, a central flow path component having a gas flow path in the stacking direction of the cell units and supplying one gas to the flow path space between the two cell plates is arranged opposite to each other. The fuel cell stack structure according to claim 1, wherein each inward electrode of the single cell and the central flow path component are electrically connected. The fuel cell stack structure according to claim 1 or 2, wherein a single cell arrangement portion of the cell plate of the cell unit is a porous support portion, and a single cell is formed on the porous support portion. The fuel cell stack structure according to claim 2 or 3, wherein a plurality of stacked cell units are electrically connected by a cell plate of the cell unit, a central flow path component, and a current collector disposed between the cell units. The fuel cell stack structure according to any one of claims 1 to 4, wherein electrical connection of a plurality of stacked cell units is performed at a peripheral portion of the cell unit. The fuel cell stack structure according to any one of claims 1 to 5, wherein adjacent cell units are electrically connected in series. The fuel cell stack according to any one of claims 1 to 5, wherein adjacent cell units are electrically connected in parallel, and a plurality of the electrically connected cell units are electrically connected in series. Structure.

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