JPH07176320A - Connecting method for flat plate type solid electrolyte fuel cell - Google Patents

Abstract

PURPOSE:To provide the connecting method for flat plate type solid electrolyte fuel cells capable of compactly arranging and connecting a plurality of flat plate type solid electrolyte fuel cells for current collection. CONSTITUTION:Flat plate-like unit cells 1, 2, 3... each arranged with a fuel electrode and an air electrode for sandwiching a flat plate type solid electrolyte layer and separators connecting the adjacent unit cells in series and distributing the fuel gas and air to the unit cells are laminated and arranged at the same height in turn, and a plurality of flat plate type solid electrolyte fuel cells are connected. The first fuel cell 1 and the adjacent second fuel cell 2 are connected by a conducting plate 4 at their upper sections, the second fuel cell 2 and the adjacent third fuel cell 3 are connected by a conducting plate 5 at their lower sections, and all fuel cells are connected in series.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for connecting flat plate type solid oxide fuel cells.

[0002]

2. Description of the Related Art Recently, fuel cells, which use oxygen and hydrogen as oxidants and fuels respectively, to directly convert the chemical energy originally possessed by the fuels into electric energy have attracted attention from the viewpoints of resource saving and environmental protection. . Flat-type solid electrolyte fuel cells using zirconia doped with yttria or the like as an electrolyte layer and using lanthanum chromite oxide or heat-resistant metal as a separator have a high operating temperature,
R & D is progressing because of high power generation efficiency, high overall efficiency by utilizing high temperature waste heat, and low vibration and noise.

In the flat plate type solid electrolyte fuel cell, a flat plate type cell in which a fuel electrode and an air electrode are arranged so as to sandwich a flat plate type solid electrolyte layer and an adjacent unit cell are electrically connected in series and each unit cell is connected. A stacked cell is formed by alternately stacking separators for distributing fuel gas and oxidant gas (air) on the battery. In particular, the internal manifold type solid electrolyte fuel cell has a compact integrated structure in which the cell constituent material such as a separator has the functions of supplying and discharging, distributing and electrically connecting an oxidant and a fuel gas. A gas supply / exhaust hole is opened in the peripheral portion of the separator, both gas are supplied / exhausted to both electrode surfaces of the unit cell from this hole, and further, in order to evenly distribute both gas to each corner of both electrode surfaces, Furthermore, gas connection grooves are formed on both electrode surfaces in order to connect adjacent batteries in series.

On the other hand, holes for gas supply / exhaust are made in the surface portion of the solid electrolyte layer of the unit cell where the electrodes are not attached, and these holes are connected in the process of stacking the cells, and the supply gas passage is provided inside the finished stack. And the exhaust gas passage is formed. If fuel and oxidant gas leak to the outside of the stack or mix inside the stack, the efficiency of the fuel cell will not only be reduced, but combustion due to mixing will cause a local temperature rise, resulting in an uneven thermal stress distribution. Uniformity shortens stack life. To prevent this, a spacer is interposed between the unit cell and the separator, and if necessary, sealing means such as a sealant is provided between these constituent members. It is covered with to improve the gas sealability.

[0005]

Recently, it is becoming necessary to operate a plurality of flat plate type solid oxide fuel cells having such a compact structure in a lump to extract a large amount of electric power. However, although the structure of a flat plate solid oxide fuel cell has been proposed and developed in many ways, when using a plurality of flat plate solid oxide fuel cells at the same time, how to arrange and connect them to operate and generate high power. About collecting current,
No full-scale study and development has been done yet.

The present invention has been made in view of the above points, and provides a method for connecting a flat plate type solid electrolyte fuel cell capable of compactly disposing and connecting a plurality of flat plate type solid electrolyte fuel cells. The purpose is to do.

[0007]

In order to solve the above-mentioned problems, the present invention electrically connects a flat battery cell in which a fuel electrode and an air electrode are arranged so as to sandwich a flat plate type solid electrolyte layer and an adjacent battery cell. In a method of connecting a plurality of flat plate type solid electrolyte fuel cells, which are connected in series and in which separators for distributing fuel gas and air are alternately laminated to each unit cell and are juxtaposed at the same height, the polarities are increased and decreased. It is characterized in that a conductive plate is placed under the two reversed fuel cells and connected in series. In the present invention, the polarities in the height direction of the fuel cell are reversed from each other, and the first fuel cell and the upper fuel cells of the second fuel cell adjacent to the first fuel cell, and the second fuel cell and the third fuel cell adjacent to the second fuel cell. It is characterized in that the lower parts of the fuel cells are connected to each other by a conductive plate and all the fuel cells are connected in series. Also,
The present invention relates to the upper parts of the first fuel cell and the second fuel cell, the second
Characteristically, the connection between the upper and lower comrades of two adjacent fuel cells such as the fuel cell and the lower comrade of the third fuel cell and the upper comrade of the third fuel cell and the fourth fuel cell is alternately repeated a plurality of times.

[0008]

The two flat plate type solid electrolyte fuel cells arranged side by side can be connected in series by one conductive plate (upper part or lower part). A combination of these three members serves as a basic unit, and by increasing the number of basic units, it is possible to connect as many flat plate solid oxide fuel cells in series as possible to take out a large voltage.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings.

FIG. 1 is an exploded view for explaining a method of connecting a flat plate type solid electrolyte fuel cell of the present invention.

In FIG. 1, flat plate type solid electrolyte fuel cells 1, 2, 3, ... Are arranged in parallel in the horizontal direction. These flat plate type solid oxide fuel cells 1, 2, 3 ... Are formed by stacking the same number of flat plate single cells and flat plate separators in the vertical direction, respectively, and therefore have the same height. Flat plate solid oxide fuel cell 1, 3 (odd number)
The upper part has-polarity and the lower part has + polarity, and the flat plate type solid electrolyte fuel cells 2, 4 (even number) have upper part with + polarity and lower part have-polarity. A conductive plate 4 is placed on top of the flat plate type solid oxide fuel cells 1 and 2 to connect these cells 1 and 2. Further, a conductive plate 5 is laid under the flat plate type solid oxide fuel cells 2 and 3 to connect these cells. In this way, the conductive plate 4 and the conductive plate 5 are used up and down differently to connect the adjacent flat plate type solid electrolyte fuel cells. In this way, all or the required number of flat plate solid oxide fuel cells are connected in series. In FIG. 1, the conductive plates 4, 5, ... Are illustrated as separated from the flat-plate solid electrolyte fuel cells 1, 2, 3, .. Although not shown, the conductive plates 4, 5, ...
Has holes for supplying and discharging the oxidant and the fuel gas to the air electrode and the fuel electrode of the unit cell, respectively.

The flat-plate type solid oxide fuel cell group, that is, the fuel cell system having the above-described structure operates as follows. When the oxidant gas and the fuel gas are supplied to the separator of the fuel cell through the holes provided in the conductive plates 4, 5, ..., They flow all over the air electrode and the fuel electrode of the unit cell, and the chemical energy of the fuel is held. Is directly converted into electric energy, and an electromotive force is generated between the upper and lower parts of the laminated stack. This electromotive force is collected by the conductive plate.

[0013]

As described above, according to the present invention, the polarities in the height direction of a plurality of flat plate type solid electrolyte fuel cells juxtaposed at the same height are reversed to each other, and Since the upper part of the adjacent second fuel cell and the lower part of the third fuel cell adjacent to the second fuel cell are connected by the conductive plates respectively, all the fuel cells are connected in series. Such an excellent effect can be obtained. (1) Since the internal manifold type solid electrolyte fuel cell has a compact structure, a large-capacity fuel cell power generation system can be manufactured by arranging a large number of these in parallel. (2) Since a plurality of fuel cells can be connected in series, a high voltage can be obtained.

[Brief description of drawings]

FIG. 1 is an exploded view illustrating a method for connecting a flat plate type solid electrolyte fuel cell of the present invention.

[Explanation of symbols]

 1 1st flat plate solid electrolyte fuel cell 2 2nd flat plate solid electrolyte fuel cell 3 3rd flat plate solid electrolyte fuel cell 4 Conductive plate 5 Conductive plate

Claims (3)

[Claims] 1. A flat plate type cell in which a fuel electrode and an air electrode are disposed so as to sandwich a flat plate type solid electrolyte layer and an adjacent cell unit are electrically connected in series, and fuel gas and air are supplied to each cell unit. In a method of connecting between a plurality of flat plate type solid electrolyte fuel cells which are alternately laminated with separators to be distributed and juxtaposed at the same height, a conductive plate is provided under two fuel cells whose polarities are inverted. A method for connecting a flat plate type solid electrolyte fuel cell, characterized in that the cells are placed in series and connected in series. 2. A flat plate type single cell in which a fuel electrode and an air electrode are arranged so as to sandwich a flat plate type solid electrolyte layer and an adjacent single cell are electrically connected in series, and fuel gas and air are supplied to each single cell. In a method for connecting a plurality of flat plate type solid electrolyte fuel cells, which are alternately laminated with separators to be distributed and juxtaposed at the same height, the polarities in the height direction of the fuel cells are reversed to each other, and A fuel cell and an upper part of a second fuel cell adjacent to the fuel cell and a lower part of the second fuel cell and a lower part of a third fuel cell adjacent to the second fuel cell are connected to each other by a conductive plate to connect all the fuel cells in series. A method for connecting a flat plate type solid oxide fuel cell, which is characterized. 3. A plate-shaped unit cell in which a fuel electrode and an air electrode are arranged so as to sandwich a plate-type solid electrolyte layer, and adjacent unit cells are electrically connected in series, and fuel gas and air are supplied to each unit cell. A method of connecting between a plurality of flat plate type solid electrolyte fuel cells, which are alternately stacked with separators to be distributed and juxtaposed at the same height, in which the first fuel cell and the upper part of the second fuel cell, and the second fuel cell And a lower part of the third fuel cell, and an upper part and a lower part of two adjacent fuel cells, such as the upper part of the third fuel cell and the fourth part of the fourth fuel cell, are alternately and repeatedly connected a plurality of times. Solid electrolyte fuel cell connection method.