JP2002050390A - Fuel cell having stack structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell having a structure in which the length of the whole structure in the direction of the stack has been made shorter by eliminating the separator and the structure of passages has been made simple, and also series or parallel connection between each generating element can be made freely. SOLUTION: Generating elements 2 of three layer structure made of a negative electrode 4, a positive electrode, and a conductor membrane 3 provided in close contact between the negative electrode and the positive electrode are arranged plural pieces in the direction of the layer. In this arrangement, the opposing electrodes between the adjoining generating elements are made to be the same pole, and the only hydrogen gas supply passage is provided between the opposing negative electrodes, and the only air supply passage is provided between the opposing positive electrodes, and hydrogen is supplied to the negative electrodes and air is supplied to the positive electrodes. The opposing electrodes between the adjoining generating elements are connected by an insulator 8 and the hydrogen gas supply passage and the air supply passage are sealed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell having a stack structure, and more particularly to a fuel cell having a stack structure in which a number of power generation elements (cells) are stacked.

[0002]

2. Description of the Related Art A fuel cell is generally used by arranging a plurality of cells called power generation elements and connecting them to form a fuel cell stack. As shown in FIG.
Has a structure in which a polymer conductor film 3 that allows only hydrogen ions to pass through is sandwiched between two electrodes including a cathode 4 and an anode 5, and both sides are further surrounded by separators 102. The cathode 4
There is provided a hydrogen electrode which is in close contact with one surface of the conductor film 3 and a current collector which is in close contact with the hydrogen electrode and in which a through hole for passing hydrogen gas is formed. The anode 5 includes an oxygen electrode that is in close contact with the other surface of the conductor film 3 and a current collector that is in close contact with the oxygen electrode and has a through hole for air passage. A plurality of such power generating elements 2 are arranged in the layer direction, and an anode 5 and a cathode 4 face each other between adjacent power generating elements, and a conductive separator for separating gas is provided between the anode 5 and the cathode 4. 102 is provided. Furthermore, a conductive spacer 103 for sealing the supplied gas is provided between each electrode and the separator 102. An air supply path 107 through which the atmosphere is introduced is formed between the anode 5 and the separator 102, and only the air can be supplied to the anode 5 side. Further, a hydrogen supply path 106 through which hydrogen gas is introduced is formed between the cathode 4 and the separator 102, and the hydrogen gas can be supplied only to the cathode 4 side.

[0003] Air (oxygen) and hydrogen gas are supplied to the separator 1
02, each of the supply paths 106, 10
7 are supplied independently of each other, the hydrogen gas is converted into hydrogen ions by the cathode 4 and passes through the conductor film 3 to form the anode 5.
Move to the side. At this time, hydrogen emits electrons, which generate a potential difference. Although the potential difference is 1 volt or less per cell, which is small, as described above, a high voltage can be obtained by stacking a large number of cells and connecting them in series via the conductive spacer 103 and the conductive separator 102. can get. In the structure in which the hydrogen gas supply path 106 and the air supply path 107 are adjacent to each other as described above, it is advantageous in terms of layout to use water generated on the anode 5 side for humidifying the cathode 4.

[0004]

However, according to the fuel cell 101 having the above-mentioned conventional stack structure, the separator 102 is always required between the adjacent power generation elements 2 and 2. It is necessary to form different gas flow paths 106 and 107, and the flow path structure becomes complicated. In addition, between the adjacent power generation elements 2 and 2, when viewed in the stacking direction, the hydrogen gas supply path 106 and the separator 10
2. The air supply passage 107 has a three-layer structure.
The length of the entire stack structure in the stacking direction increases, which is against the demand for compactness. In addition, in the conventional stack structure, only the connection in series can be realized, which can contribute to the increase in the output of the entire stack structure. Can not respond.

Therefore, the present invention makes it possible to reduce the length of the entire stack structure in the stack direction by eliminating the need for a separator, to simplify the structure of the flow path, and to optionally connect a series or parallel connection between the power generating elements. It is an object of the present invention to provide a fuel cell having a stack structure that can be realized at a high speed.

[0006]

In order to achieve the above object, the present invention provides a cathode having a hydrogen electrode and a current collector, an anode having an oxygen electrode and a current collector, and In order to arrange a plurality of power generating elements having a three-layer structure including a conductor film provided in close contact with each other in the layer direction and to supply hydrogen to the hydrogen electrode and supply oxygen to the oxygen electrode, In a fuel cell stack structure in which a hydrogen gas supply path and an air supply path are arranged between the power generation elements, the respective power generation elements are arranged so that the opposing electrodes between adjacent power generation elements have the same polarity, and the opposing cathodes Only the hydrogen gas supply path is provided between the anodes, and only the air supply path is provided between the opposed anodes. The opposed electrodes between the adjacent power generation elements are connected by an insulator to form the hydrogen gas supply path and the Has a stack structure to seal the air supply path It has to offer fee battery.

Here, between the opposing electrodes between the adjacent power generating elements is connected with an insulator to seal the hydrogen gas supply path and the air supply path, and each power generation element is optionally connected with an external conductor. To optionally provide series or parallel or a combination of series and parallel.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A fuel cell having a stack structure according to an embodiment of the present invention will be described with reference to FIGS. The fuel cell 1 having the stack structure shown in FIG. 1 is an example in which four power generation elements 2 are connected in series.

As shown in FIG. 1, the power generating element 2 has a configuration in which a polymer conductive film 3 that allows only hydrogen ions to pass therethrough is sandwiched between two electrodes including a cathode 4 and an anode 5. The cathode 4
There is provided a hydrogen electrode which is in close contact with one surface of the conductor film 3 and a current collector which is in close contact with the hydrogen electrode and in which a through hole for passing hydrogen gas is formed. The anode 5 includes an oxygen electrode that is in close contact with the other surface of the conductor film 3 and a current collector that is in close contact with the oxygen electrode and has a through hole for air passage. Then, a plurality of such power generating elements 2 are arranged in the layer direction, and the respective power generating elements 2 are arranged such that opposing electrodes between adjacent power generating elements have the same polarity. Only the hydrogen gas supply path 6 is provided between the adjacent cathodes 4, and only the air supply path 7 is provided between the adjacent anodes 5.
Further, between the opposing electrodes between the adjacent power generating elements 2 and 2, the hydrogen gas supply path 6 and the air supply path 7 are respectively sealed by an insulator 8.

Each power generating element 2 has an external conductor 9A-
It is arbitrarily connected at 9C. In the structure using four power generating elements 2 shown in FIG. 1, the cathode 4 of the first power generating element 2 and the anode 5 of the second power generating element 2 are connected by a conducting wire 9A,
The cathode 4 of the second power generation element 2 and the anode 5 of the third power generation element 2
Are connected by a conducting wire 9B, and the cathode 4 of the third power generating element 2
And the anode 5 of the fourth power generation element 2 are connected by a conducting wire 9C, and are connected in series as a whole.

When hydrogen gas is supplied to the hydrogen supply passage 6,
Hydrogen is supplied to the hydrogen electrode through the through holes of the current collectors of the cathodes 4 and 4 of the power generating elements 2 and 2 facing each other. The hydrogen gas is converted into hydrogen ions by the hydrogen electrode, and the hydrogen ions pass through the conductor film 3 and move to the oxygen electrode side. At the same time, since air (oxygen) is supplied to the air supply path 7, oxygen is supplied to the oxygen electrode via the through-hole of the current collector of the anode 5. Then, a reaction between hydrogen ions and oxygen ions occurs at the oxygen electrode, and water is generated. At the same time, hydrogen emits electrons to the hydrogen electrode to generate a potential difference, which becomes an output, and a desired power can be output by the above-described series connection.

In the fuel cell 11 having the stack structure shown in FIG. 2, the arrangement direction of the power generation elements and the arrangement of the hydrogen supply passage 6 and the air supply passage 7 are the same as those of the stack structure of FIG. 19E shows an example in which four power generating elements 2 are connected in parallel. The cathodes 4 of the first to fourth power generation elements 2 are connected by conductors 19A and 19B, and the anodes of the first to fourth power generation elements are connected by conductor 19
By connecting at C, 19D, and 19E, parallel connection can be realized, and it is possible to respond to a demand for a stable supply of low output rather than a demand for an increase in output.

The fuel cell 21 having the stack structure shown in FIG. 3 has the same arrangement direction of the power generating elements and the arrangement of the hydrogen supply path 6 and the air supply path 7 as the stack structure of FIGS. This is an example in which four power generating elements are combined in parallel and in series by conducting wires 29A to 29E. Conductors 29A and 29B are connected in parallel between the anodes and the cathodes of the first and second power generation elements 2, respectively, and the conductors 29C and 29C are also connected between the anodes and the cathodes of the third and fourth power generation elements, respectively.
Connect in parallel with D. Then, the second and third power generation elements are connected in series by the conducting wire 29E. A desired output can be obtained by the combination of series and parallel as described above.

The stack structure of the fuel cell according to the present invention comprises:
The present invention is not limited to the above embodiment, and various modifications and improvements can be made within the scope described in the claims. For example,
The hydrogen electrode of the present invention is impregnated with a fullerene derivative-based proton conductor, and the oxygen electrode is impregnated with an organic proton conductor, so that even when the fuel cell is operated in a non-humidified state, the cathode is Proton conduction of hydrogen ions in the inside can be satisfactorily performed. In this case,
Since it is not necessary to use the water generated at the anode for humidifying the cathode, the configuration of the present invention in which the air supply path and the hydrogen supply path are not close to each other and are separated from each other by each cell, It is advantageous to impregnate a fullerene derivative-based proton conductor. Further, in the oxygen electrode, water is generated by the reaction between hydrogen ions and oxygen ions, so that the oxygen electrode can be humidified with the water. Furthermore, by adopting a structure in which the conductor membrane is impregnated with a fullerene derivative-based proton conductor, hydrogen ion proton conduction can be performed in the conductor membrane even in a non-humidified state.

[0015]

According to the fuel cell having the stack structure according to the first aspect, the power generating elements are arranged such that the electrodes facing each other between the adjacent power generating elements have the same polarity, and between the opposing cathodes. Only the hydrogen gas supply path is provided, and only the air supply path is provided between the opposed anodes. The opposed electrodes between the adjacent power generation elements are connected by an insulator to form the hydrogen gas supply path and the air supply path. , It is not necessary to provide a separator between adjacent power generating elements to separate gas, so that the mechanical configuration of the gas flow path is simplified and the length in the stack direction can be reduced. it can.

According to the fuel cell having the stack structure according to the second aspect, since each power generating element is provided so as to be arbitrarily connectable with the external conductor, not only the direct connection but also the desired parallel or series and parallel Any combination can be provided, the degree of freedom of connection can be increased, and the voltage and current can be changed to desired values.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a fuel cell having a stack structure according to an embodiment of the present invention, which is configured by series connection.

FIG. 2 is a cross-sectional view of a fuel cell having a stack structure according to an embodiment of the present invention, which is configured by parallel connection.

FIG. 3 is a cross-sectional view of a fuel cell having a stack structure according to an embodiment of the present invention, which is configured by a combination of series connection and parallel connection.

FIG. 4 is a cross-sectional view of a fuel cell having a conventional stack structure.

[Explanation of symbols]

 1, 11, 21 Fuel cell having stack structure 2 Cell 3 Conductor film 4 Cathode 5 Anode 6 Hydrogen supply path 7 Air supply path 8 Insulator 9A-9C, 19A-19E, 29A-29E Conductor

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[Procedure amendment]

[Submission date] August 16, 2000 (2008.1.
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claim 1

[Correction method] Change

[Correction contents]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

In order to achieve the above object, the present invention provides a cathode having a hydrogen electrode and a current collector, an anode having an oxygen electrode and a current collector, and In order to arrange a plurality of power generating elements having a three-layer structure including a conductor film provided in close contact with each other in the layer direction and to supply hydrogen to the hydrogen electrode and supply oxygen to the oxygen electrode, In a fuel cell having a stack structure in which a hydrogen gas supply path and an air supply path are arranged between power generation elements, the respective power generation elements are arranged so that opposing electrodes between adjacent power generation elements have the same polarity, and face each other. Only the hydrogen gas supply path is provided between the cathodes, and only the air supply path is provided between the opposed anodes. The opposed electrodes between the adjacent power generation elements are connected by an insulator to form the hydrogen gas supply path and A stack structure for sealing the air supply path And a fuel cell having the same.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction contents]

A fuel cell having a stack structure according to the present invention
The pond is not limited to the embodiments described above, and various modifications and improvements are possible within the scope described in the claims. For example, the hydrogen electrode of the present invention is impregnated with a fullerene derivative-based proton conductor, and the oxygen electrode is impregnated with an organic-based proton conductor, so that even when the fuel cell is operated in a non-humidified state. In addition, proton conduction of hydrogen ions in the cathode can be favorably performed. In this case, since the water generated at the anode does not need to be used for humidifying the cathode, the configuration of the present invention in which the air supply path and the hydrogen supply path are not close to each other but are separated from each other by each cell. Therefore, it is advantageous to impregnate the hydrogen electrode with a fullerene derivative-based proton conductor. Further, in the oxygen electrode, water is generated by the reaction between hydrogen ions and oxygen ions, so that the oxygen electrode can be humidified with the water. Furthermore, by adopting a structure in which the conductor membrane is impregnated with a fullerene derivative-based proton conductor, hydrogen ion proton conduction can be performed in the conductor membrane even in a non-humidified state.

Claims (2)

[Claims] 1. A three-layer structure comprising a cathode having a hydrogen electrode and a current collector, an anode having an oxygen electrode and a current collector, and a conductor film provided in close contact between the cathode and the anode. A plurality of power generating elements having a structure are arranged in the layer direction, and a hydrogen gas supply path and an air supply path are arranged between the power generation elements to supply hydrogen to the hydrogen electrode and supply oxygen to the oxygen electrode. In the fuel cell stack structure, each power generating element is arranged so that the opposing electrodes between adjacent power generating elements have the same polarity, only the hydrogen gas supply path is provided between the opposing cathodes, and between the opposing anodes. Has a stack structure in which only an air supply path is provided, and the opposed electrodes between adjacent power generation elements are connected by an insulator to seal the hydrogen gas supply path and the air supply path. Fuel cell. 2. The fuel cell having a stack structure according to claim 1, wherein each power generating element is arbitrarily connected by an external conductor to provide a series or parallel or a combination of series and parallel. .