JPH05174861A - Structure for solid electrolyte type fuel cell module - Google Patents

Abstract

PURPOSE:To provide a module structure which enables output to be detected every single cell. CONSTITUTION:Single cells 21 are arranged on the outer circumference of a conductive center current collector 27, and the interconnectors 26 of the cells are electrically continued to the center current collector 27. The single cells 21 are housed in the inside of a holding member 28 which connects six conductors 29 in a cylindrical shape with insulating connectors 30, and the fuel cells 25 formed by the respective single cells 21 are electrically continued to each corresponding conductor 29.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell using a solid electrolyte, and more particularly to a structure of a module in which a plurality of cylindrical single cells are combined.

[0002]

2. Description of the Related Art A solid oxide fuel cell is an air electrode (anode) made of, for example, a perovskite-type lanthanum-based composite oxide with a solid electrolyte such as yttria-stabilized zirconia (YSZ) or calcia-stabilized zirconia (CSZ) interposed therebetween. And a fuel electrode (cathode) composed mainly of nickel and the like are provided, and an electromotive force is obtained by a redox reaction between the fuel gas and air through the solid electrolyte. In this type of fuel cell, it is necessary to separate the fuel gas flow path and the air flow path in an airtight state. Therefore, the solid electrolyte may be formed in a cylindrical shape, and the electrodes may be provided on the inner peripheral surface and the outer peripheral surface thereof. preferable. In addition, since the electric power obtained by a single cell is small, conventionally, a plurality of single cells are connected in series and parallel to form a module, and a plurality of these are used to obtain the required electric power.

FIG. 3 is a sectional view of a module composed of six cylindrical single cells 1. Each single cell 1 shown here has an air electrode 3 formed on the inner peripheral surface of a cylindrical solid electrolyte 2. In addition, the fuel electrode 4 is formed on the outer peripheral surface of the solid electrolyte 2 in a partially cut-out state, and the interconnector 5 that is electrically connected to the air electrode 3 is provided so as to project at the cut-out portion of the fuel electrode 4. .. These unit cells 1 are arranged in close contact with each other on the outer periphery of the anode side current collector 6, and each interconnector 5 is electrically connected to the conductive felt 7 provided on the outer peripheral surface of the anode side current collector 6. Making contact. Further, all of them are housed in a cylindrical cathode-side current collector 8, and the fuel electrode 4 of each unit cell 1 is electrically connected to a conductive felt 9 provided on the inner peripheral surface of the cathode-side current collector 8. Touching the condition. The central portion of each unit cell 1 serves as an air flow passage 10, and the outer peripheral portion of each unit cell 1 serves as a fuel gas flow passage 11 for hydrogen gas or the like.

The module shown in FIG. 4 is constructed by arranging nine unit cells 1 between a pair of current collector plates 12 and 13 in a matrix of 3 columns and 3 rows. The unit cells 1 in each row arranged in the vertical direction have their interconnectors 5 electrically connected to the outer peripheral surface of the fuel electrode 4 of the adjacent unit cell 1 via the conductive felt 14, and further in FIG. In the unit cells 1 in each row arranged in the direction, the fuel electrodes 4 are electrically connected to each other via the conductive felt 14.

[0005]

Therefore, in the module shown in FIG. 3, electric power can be taken out from each of the current collectors 6 and 8 by flowing air or fuel gas into each of the flow paths 10 and 11, and FIG. Also in the module shown in FIG.
Electric power can be obtained by using the upper current collector plate 12 as an anode and the lower current collector plate 13 as a cathode. The output thus obtained is the sum of the outputs of the individual unit cells 1.
Has different power generation efficiency depending on the temperature, the supply state of air or fuel gas to the surface of the solid electrolyte 2, the degree of deterioration of the solid electrolyte 2, and so on, it is necessary to manage each single cell 1 in order to increase the output of each module. .. However, with the conventional module described above, only the output as a whole can be known, so even if the power generation efficiency of any single cell is poor, air or fuel gas will flow evenly to each single cell. Therefore, energy efficiency may deteriorate,
Further, when the output of the module as a whole is lowered due to the poor power generation efficiency of any one of the cells, the entire module has to be replaced, which results in an increase in maintenance cost.

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a structure of a fuel cell module capable of knowing the output status of each single cell constituting the module. .

[0007]

In order to achieve the above-mentioned object, the present invention has one of an air electrode and a fuel electrode formed on the inner peripheral surface of a cylindrical solid electrolyte, and the other Electrodes are formed on the outer peripheral surface of the solid electrolyte,
And in the structure of the solid electrolyte type fuel cell module consisting of a plurality of single cells provided with an interconnector that is electrically connected to the electrode on the inner peripheral side and is not electrically connected to the electrode on the outer peripheral side and is provided to project to the outer peripheral side in the radial direction Each unit cell is arranged around a conductive center current collector by electrically connecting each interconnector to the center current collector, and these unit cells are surrounded by a cylindrical holding material. In addition, the holding material is provided with a conductor that is electrically independent for each single cell and is electrically connected to the electrode on the outer peripheral side of each single cell.

[0008]

In the unit cell constituting the module of the present invention, one of air and fuel gas is caused to flow in the central part and the other is caused to flow to the outer peripheral side, whereby an oxidation-reduction reaction occurs via the solid electrolyte, and electromotive force is generated. Cause The electrode on the inner peripheral side of each unit cell is electrically connected to the central current collector through the interconnector, but the electrode on the outer peripheral side is electrically connected to the electrically independent conductor for each unit cell. Since they are conducting, the output from each unit cell is individually performed via the central current collector and the conductor provided in the holding material. If the conductors on the outer peripheral side are combined at one end, the output of the module as a whole can be obtained, but since the conductor on the outer peripheral side and the central current collector can output each single cell. The output state of each single cell can be known and managed individually.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing an embodiment of the present invention. A fuel cell module 20 shown here is constituted by six single cells 21. Has been done. The unit cell 21 has a structure similar to that of a conventional unit cell, and its sectional shape is shown in FIG. That is, calcia-stabilized zirconia (C
The air electrode 23 is formed on the entire outer peripheral surface of the support tube 22, which is a porous tube made of SZ) or alumina (Al203), and the solid electrolyte 24 is formed on the outer periphery in a partially cut state. Further, the fuel electrode 25 is formed in a state where a part thereof is cut out on the outer periphery thereof. Then, the interconnector 26 is formed in the notched portion of the solid electrolyte 24 so as to straddle both ends thereof.

The six unit cells 21 are composed of a central current collector 27.
Are arranged on the circumference centered on the center and each of the interconnectors 26 is electrically connected to the central collector 27 thereof. The central collector 27 is made of, for example, nickel (Ni).
) A rod and a Ni felt, and by arranging the Ni felt on the outer periphery of the Ni rod, each interconnector 26 is in contact with the central current collector 27 via the Ni felt having a buffering action.

As described above, the six unit cells 21 equally arranged around the central current collector 27 have the cylindrical holding member 2 in that state.
8 is housed inside and fastened so as to be integrated.
This holding material 28 is, for example, Ni or Ni and ZrO2.
Six conductors 29 having a substantially arc-shaped cross section consisting of and are connected in a cylindrical shape by a connecting tool 30 made of an insulator such as alumina. A certain fuel electrode 25 is electrically connected to the inner peripheral surface of a corresponding conductor 29 via a Ni felt 31.

The central portion of each unit cell 21 is the air flow path 3
2, and the cavity on the outer peripheral side of each unit cell 21 serves as a fuel gas passage 33 for hydrogen gas or the like. Therefore, the module 20 shown in FIG. 1 operates with the central current collector 27 as an anode and each conductor 29 as a cathode.

That is, when air is flown through the air flow path 32 and hydrogen gas, for example, is flowed through the fuel gas flow path 33, a redox reaction occurs via the solid electrolyte 24. In that case, since oxygen ions move the solid electrolyte 24 from the air electrode 23 side to the fuel electrode 25 side, in each single cell 21, the air electrode 23
Is the anode, and the fuel electrode 25 is the cathode. Therefore, in the module 20 as a whole, the central current collector 27 is the anode and each conductor 29 is the cathode. Since the conductor 29 serving as the cathode is independent for each single cell 21, if the conductors 29 are combined into one, the conductor 29 becomes the cathode in the module 20, while each conductor 29 is divided into one. If so, it can be output for each single cell 21. In other words, in the module shown in FIG. 1, the electromotive force of each single cell 21 can be known, and the energy efficiency can be increased by adjusting the air supply amount of each single cell 21 based on the measurement result. In addition, it is possible to determine pass / fail for each single cell 21.

In the above embodiment, an example in which a part of the holding material 28 is constituted by the conductor 29 has been shown, but the present invention is not limited to the above embodiment, and the outer periphery of the unit cell is not limited. The conductors that are electrically connected to the side electrodes may be individually provided on the inner peripheral surface of the cylindrical holding member so as to correspond to the individual cells.

[0015]

As described above, according to the present invention,
Since it is possible to know the electromotive force and operating status of each unit cell that composes the module, it is possible to manage the air supply amount and replacement time for each unit cell, resulting in efficient power generation. In addition, management and maintenance costs can be reduced.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view of the unit cell.

FIG. 3 is a sectional view of a conventional cylindrical module.

FIG. 4 is a cross-sectional view of a conventional module in which single cells are arranged in a matrix.

[Explanation of symbols]

20 ... Module, 21 ... Single cell, 23 ... Air electrode, 24 ... Solid electrolyte, 25 ... Fuel electrode, 26 ... Interconnector, 27 ... Central current collector, 28 ... Holding material, 29 ... Conductor.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takenori Nakajima 1-5-1 Kiba, Koto-ku, Tokyo Fujikura Electric Line Co., Ltd.

Claims (1)

[Claims] 1. An air electrode or a fuel electrode is formed on the inner peripheral surface of a cylindrical solid electrolyte, and
The other electrode is formed on the outer peripheral surface of the solid electrolyte, and a plurality of interconnectors, which are electrically connected to the electrode on the inner peripheral side and not connected to the electrode on the outer peripheral side, are provided so as to protrude in the outer peripheral side in the radial direction. In the structure of the solid oxide fuel cell module consisting of single cells, each single cell is arranged around a conductive central current collector with each interconnector electrically connected to the central current collector, and These unit cells are surrounded by a cylindrical holding member, and the holding member is provided with a conductor that is electrically independent for each unit cell and is electrically connected to an electrode on the outer peripheral side of each unit cell. A structure of a solid oxide fuel cell module characterized by the above.