JP2005216581A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell wherein a current density distribution is uniformized to stabilize a power generation current by spreading a supply gas throughout electrodes with uniform concentration, and a gas leakage prevention measure is facilitated by equalizing pressure in a gas passage. <P>SOLUTION: Each separator 4 for holding electrodes 3 is composed of a first separator 5 and a second separator 6; a part contacting the electrodes 3 is recessed on a surface contacting the electrode 3 of each first separator 5 to form a first gas storage space 7; a second gas storage space 8 having nearly the same shape as that of the first gas storage space 7 is formed on a joint surface between each first separator 5 and the corresponding second separator 6; and the first gas storage space 7 is made to communicate with the second gas storage space 7 through multiple communication holes 9, whereby the supply gas introduced into the second gas storage space 8 can be run into the first gas storage space 7 through the communication holes 9 and supplied to each electrode 3. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to the shape of a gas flow path of a fuel cell.

The power generation capacity of a fuel cell is proportional to the area where chemical reaction of the electrode has occurred, and in order to continue stable power generation, it is desirable to supply gas at a uniform concentration throughout the electrode. In order to increase the size of the gas flow path, a meandering flow path is used. (For example, refer to Patent Document 1).
JP 2002-83610 A (FIG. 1)

  However, because of the shape of the meandering channel, it is difficult to supply the supply gas to the entire electrode at a uniform concentration, it is difficult to generate power stably, and the pressure in the gas channel is not uniform, thus preventing gas leakage There was a problem that measures were difficult.

  According to the first aspect of the present invention, a fuel cell is constructed by sandwiching both surfaces of an electrolyte membrane with electrodes and sandwiching the outside of the electrode with a separator, and supplying fuel gas to one electrode. In the fuel cell for supplying the oxidant gas to the other electrode, the separator is composed of a first separator stacked on the outer side of the electrode and a second separator stacked on the outer side of the first separator. A first gas storage space that is recessed over a wide range is formed on the surface in contact with the electrode, and a second gas storage space having substantially the same shape as the first gas storage space is formed on the joining surface of the first separator and the second separator. The first gas storage space and the second gas storage space are communicated with each other through a large number of communication holes so that the gas flows from the second gas storage space toward the first gas storage space.

  According to a second aspect of the present invention, in the fuel cell according to the first aspect, a gas discharge through-hole penetrating in the thickness direction is formed in the vicinity of two diagonal corners of the first separator and the second separator. A gas introduction through hole is formed in the inner surface of the first separator, the gas exhaust groove communicating with the gas exhaust through hole of the first separator facing from the first gas storage space, and penetrating in the thickness direction in the center of the second separator. When the fuel cell is continuously provided on the outer side surface of the second separator, a gas introduction groove is formed in which the gas introduction through hole communicates with the gas discharge through hole of another fuel cell.

  In the fuel cell of the present invention, the supply gas spreads over the entire electrode at a uniform concentration, so that the current density distribution is uniform, the generated current is stable, and the pressure in the gas flow path is uniform, so that gas leakage prevention measures are taken. The effect is easy.

  A separator for sandwiching the electrode is composed of a first separator and a second separator, and a portion in contact with the electrode is formed on the surface of the first separator in contact with the electrode to form a first gas storage space. A second gas storage space having substantially the same shape as the first gas storage space is formed on the joint surface with the two separators, and the first gas storage space and the second gas storage space are communicated with each other through a plurality of communication holes; The supply gas introduced into the storage space flows through the communication hole to the first gas storage space and can be supplied to the electrode.

  A fuel cell according to a first embodiment of the present invention will be described with reference to the accompanying drawings of FIGS.

  The fuel cell is formed by laminating a plurality of fuel battery cells 1 including an electrolyte membrane 2, an electrode 3 that sandwiches both surfaces of the electrolyte membrane 2, and a separator 4 that sandwiches the outside of the electrode 3. The fuel gas is supplied to the electrode 3 on one side of the electrolyte membrane 2 through the gas flow path formed in the separator 4, and the oxidant gas is supplied to the electrode 3 on the other side.

  The separator 4 includes a first separator 5 stacked on the outside of the electrode 3 and a second separator 6 stacked on the outside of the first separator 5. In the first separator 5, the portion in contact with the electrode 3 is formed in a circular shape on the surface in contact with the electrode 3 to form a first gas storage space 7, and the first gas is formed in the joint surface between the first separator 5 and the second separator 6. A second gas storage space 8 is formed by being recessed substantially in the same shape as the storage space 7, and a large number of communication holes 9 communicating between the first gas storage space 7 and the second gas storage space 8. Are formed at appropriate intervals in the whole part.

  Further, gas discharge through holes 10 penetrating in the thickness direction are formed in the vicinity of two opposite corners of the first separator 5 and the second separator 6, and face the inner side surface of the first separator 5 from the first gas storage space 7. A gas discharge groove 11 communicating with the gas discharge through hole 10 of the first separator 5 is formed, a gas introduction through hole 12 penetrating in the thickness direction of the central portion of the second separator 6 is formed, and the outer surface of the second separator 6 A gas introduction groove 13 is formed through which the gas introduction through hole 12 communicates with the gas discharge through hole 10 of another fuel battery cell 1 when the fuel cell 1 is continuously provided. In the electrolyte membrane 2, a hole 14 is formed at a portion facing the gas discharge through hole 10.

  As a result, the gas introduced from the gas introduction through-hole 12 temporarily accumulates in the second gas storage space 8 and flows from the second gas storage space 8 through the many communication holes 9 to the first gas storage space 7 to be uniform over the entire electrode. Spread by concentration. Then, the gas flows through the gas discharge groove 11 to the gas discharge through hole 10 and then flows into the gas introduction groove 13 of the next fuel cell 1. Thus, in the fuel cell, gas flows through all the fuel cells 1. As for the gas, fuel gas is supplied from one separator 4, and oxidant gas is supplied from the other separator 4.

  The through holes 15 formed at the top and bottom of the center of the fuel cell 1 are for flowing cooling water, and the eight through holes 16 formed in the vicinity of the four corners of the fuel cell 1 are a plurality of fuel cells. The guide pin used for connecting 1 is inserted.

The fuel cell which concerns on this invention is shown, (a) is a front view, (b) is a right view. It is the sectional view on the AA line of FIG. 1 is an exploded perspective view showing a fuel cell according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel cell 2 Electrolyte membrane 3 Electrode 5 1st separator 6 2nd separator 7 1st gas storage space 8 2nd gas storage space 9 Communication hole 10 Gas discharge through-hole 11 Gas discharge groove 12 Gas introduction through-hole 13 Gas introduction groove

Claims (2)

  In a fuel cell in which both surfaces of an electrolyte membrane are sandwiched between electrodes and the outside of the electrode is sandwiched between separators to form a fuel cell, fuel gas is supplied to one electrode, and oxidant gas is supplied to the other electrode The separator is composed of a first separator laminated on the outside of the electrode and a second separator laminated on the outside of the first separator, and is recessed over a wide range on the surface in contact with the electrode of the first separator. A first gas storage space is formed, a second gas storage space having substantially the same shape as the first gas storage space is formed on a joint surface between the first separator and the second separator, and the first gas storage space is formed. And the second gas storage space are communicated with each other through a large number of communication holes so that gas flows from the second gas storage space toward the first gas storage space.   A gas discharge through hole penetrating in the thickness direction is formed in the vicinity of two opposite corners of the first separator and the second separator, and the first separator facing the inner surface of the first separator from the first gas storage space is formed. A gas discharge groove communicating with the gas discharge through hole is formed, a gas introduction through hole penetrating in the thickness direction is formed in a central portion of the second separator, and the fuel cell is connected to an outer surface of the second separator. 2. The fuel cell according to claim 1, wherein a gas introduction groove is formed in which the gas introduction through hole communicates with a gas discharge through hole of another fuel cell when the gas introduction through hole is provided.

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