JPH0492373A - Gas fuel cell - Google Patents

Abstract

PURPOSE:To reduce the sealing positions widely and to improve the handling efficiency extensively by feeding a moisture from water absorbent polymers to maintain the wet condition when the moisture content of ion exchange membranes is reduced, and preventing the water from leaking when the moisture content reaches a satulation. CONSTITUTION:In this gas fuel cell, when the moisture content of ion exchange membranes 11... is reduced, the moisture is fed from water absorbent polymers 30... to the ion exchange membranes 11... to maintain the wet condition of the ion exchange membranes 11..., and when the moisture content of the water absorbent polymers 30... is reduced, the moisture is fed to the water absorbent polymers 30... from a water supply tank 100 provided outside the cell. As a result, the wet condition of the ion exchange membranes can be maintained without storing a plenty of water in the fuel cell. And since the water absor bent polymers 30... are provided contacting to the ion exchange membranes 11..., the water to feed to the ion exchange membranes 11... is solidified, and the sealing positions are reduced widely. Furthermore, the orientation of installing, the portability, and the handling, of the cell can also extensively be improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a gaseous fuel cell using an ion exchange membrane as an electrolyte, and in particular to a gas fuel cell that uses an ion exchange membrane as an electrolyte. This invention relates to a gaseous fuel cell that can maintain a wet state.

[Prior Art] FIG. 5 is a schematic cross-sectional view of an example of a conventional gas fuel cell using an ion exchange membrane as an electrolyte. This kind of gas fuel cell 1
Now, the anion exchange membrane (SPE) that constitutes the electrolyte
a positive electrode 3 and a negative electrode 4 arranged to sandwich the ion exchange membrane 2; an air supply path 5 that supplies air as an oxidizing gas to the positive electrode 3; and hydrogen as a fuel gas. A cell includes a hydrogen gas supply path 6 that supplies gas to the negative electrode 4. A water trap section 7 is formed at the bottom of the hydrogen gas supply path 6.
Water and hydrogen gas are supplied to the positive electrode 4, the water is stored in the water trap 7, and the hydrogen gas rises along the positive electrode 4 and is discharged.

Since the ion exchange membrane 2 is formed of an anion exchange membrane, as power generation progresses, water is generated at the negative electrode 4 by the reaction between hydrogen and hydroxide ions, and the generated water is absorbed by the ion exchange membrane. Alternatively, the water accumulates in the trap section 7 due to the action of gravity. When the water content of the ion exchange membrane 2 decreases during power generation, water in the trap section 7 is absorbed into the ion exchange membrane 2 as shown by arrow a. When water is trapped in the water trap section 7, hydrogen gas bubbles (
(bubbling) keeps the humidity in the hydrogen gas supply path 6 high. In addition, since the water vapor evaporating from the ion exchange membrane 2 in the direction shown by the arrow B is diffused by the flowing air in the air supply path 5, the humidity inside the path is kept high.

In this way, conventionally, the ion exchange membrane 2 and the electrodes (3, 4) that form the ion exchange membrane 2 are kept moist by the water stored in the water trap section 7. 4) This prevents an increase in the resistance of the ion exchange resin component that has entered the pores.

[Problem to be solved by the invention] However, since conventional gas fuel cells store a large amount of water inside, the water sealing structure has become an important problem, and the direction of battery installation has been unclear. However, there were problems with poor portability and handling. This point will be explained using the seal structure of the water trap section 7 in the conventional example shown in FIG. 5 as an example.

FIG. 6 is an exploded perspective view for specifically explaining the joining structure between the ion exchange membrane 2 and the frame 9 that constitutes the hydrogen gas supply path 6. As shown in this figure, in the past, the ion exchange membrane 2 constituting the electrolyte was made a part of the wall, and the gasket 8
The water trap section 7 is sealed using a water trap. However, the gasket 8
When the ion exchange membrane 2 is a type of plastic film, it has no rigidity, and the ion exchange membrane 2 bends, making it difficult to securely seal with the gasket 8. It has been considered to thermally weld the ion exchange membrane 2 and the gasket 8, but since ion exchange membranes usually undergo thermal decomposition before melting when heated, thermal welding could not be carried out. For the above reasons,
Conventional batteries have had the problem of being cumbersome to seal.

In addition, since there is a large amount of water trapped in the water trap section 7, the posture of the device is naturally limited to one direction (especially in the vertical direction).
There was a problem in that portability and handleability were significantly impaired.

[Means for Solving the Problems] The present invention provides at least one electrode in which a positive electrode to which an oxidant gas is supplied and a negative electrode to which a fuel gas is supplied are arranged with an ion exchange membrane constituting an electrolyte sandwiched therebetween. In the invention according to claim 1, the gas fuel cell is characterized in that a water absorbing body made of a water absorbing polymer is placed in contact with the ion exchange membrane, and water is supplied to the water absorbing body in a manner that prevents water leakage. connecting roads.

In the invention according to claim 2, the water absorbing body is arranged so as to be in contact with the electrode that generates water among the positive electrode and the negative electrode and the surface of the ion exchange membrane on the side of the electrode.

In the invention of claim 3, a control valve that controls the water supply to the water supply channel according to a control signal, a water content detection means that detects the water content of the water absorbing body, and a water content detection means based on the detection signal from the water content detection means. The system further includes a water supply control device that controls the control valve.

In the invention according to claim 4, the water absorbent body is arranged in a water absorbent body storage space formed between the electrode (positive electrode or negative electrode) and the ion exchange membrane. The water-absorbing body storage space is constructed in such a shape that gas does not flow through the water-absorbing body due to expansion when the water-absorbing body can sufficiently supply moisture to the ion exchange membrane. Further, the water content detection means is constituted by a detection gas supply means for supplying a detection gas from one end of the water absorbent storage space and a gas detector that detects the detection gas exiting from the other end of the water absorption body storage space.

In the invention of claim 5, as the detection gas supply means,
A means for supplying gas to the electrode (positive or negative electrode) is used.

In the invention of claim 6, when the battery includes a plurality of cells, the other ends of the water absorbent storage spaces of each cell are connected by a connecting gas passage, and one gas detector is connected to the other end of the water absorbing body storage space of each cell. Place it on the exit side.

[Function of the Invention] As in the invention of claim 1, when a water absorbing body made of a water absorbing polymer is placed in contact with an ion exchange membrane and a water supply channel is connected to the water absorbing body in a manner that prevents water leakage, ion exchange When the water content of the membrane decreases, water is replenished from the water absorber made of a water-absorbing polymer to the ion exchange membrane due to the difference in osmotic pressure, and the ion exchange membrane is maintained in a moist state. Even if a water-absorbing polymer absorbs water from a water supply channel, it only stops absorbing water once it reaches a saturated state, and it does not substantially leak water like a sponge.

Further, as in the invention of claim 2, when the water absorbing body is arranged so as to be in contact with the electrode that generates water among the positive and negative electrodes and the surface of the ion exchange membrane on the electrode side, a part of the generated water is absorbed. It can absorb water with a water absorbent.

According to the third aspect of the invention, the water content of the water absorbing body is detected by the water content detection means, and when the water content of the water absorbing body becomes low, the control valve is opened to supply water to the water absorbing body.

Therefore, according to the present invention, water can be automatically supplied via the control valve, so that backflow from the water supply channel can be prevented.

According to the fourth aspect of the invention, the water content of the water absorbing body can be easily detected without arranging a sensor inside the cell. When the water absorber is unable to supply sufficient water to the ion exchange membrane, the water absorber contracts due to the decrease in water content.
A gap is created between the water absorbent body and the water absorbent body storage space, and the detection gas supplied from the detection gas supply means flows out through the water absorbent body storage space. By detecting this flowing detection gas with a gas detector, the water content of the water absorbing body can be determined.

Generally speaking, it is possible to detect whether the water content of the water absorbing body has fallen below a predetermined level by the presence or absence of outflow of the detection gas.
By detecting the amount of outflowing detection gas per unit time, it is also possible to detect the water content in some detail.

According to the invention of claim 5, since the gas (oxidant gas or fuel gas) supplied to the electrode (positive electrode or negative electrode) is used as the detection gas, a special gas supply means is required for detecting the water content. There is no need to use it. When using an oxidizing gas as the detection gas, an oxygen sensor may be used as the gas detector, and when using fuel gas as the detection gas, a combustible gas sensor is used as the gas detector.

According to the invention of claim 6, when the battery includes a plurality of cells, the water content of the water absorbing body can be detected with one gas detector.

[Example] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic diagram showing the schematic configuration of an embodiment of the gas fuel cell of the present invention, and FIG. 1 schematically shows a state in which three sets of gas fuel cells are connected in series by a current collector. It is shown in Note that FIG. 1 schematically shows only the structure of the cell group, and does not show the structure of the cell fixing part, the fuel gas supply means, etc. In the same figure, 1-Oa to 10c
indicate cells, and these three cells 10a
~10c is a bipolar plate or bipolar current collector 2
connected in series by 0a and 20b, cells 1 on both sides
A unipolar current collector 20c is placed on the outside in the stacking direction of 0a and 10c.
and 20d are arranged.

30... is a water-absorbing polymer constituting the water-absorbing body,
A water supply channel 40 is connected to the water-based winter clothing polymer.

The cells 10a to 10c are composed of positive electrodes 12 and negative electrodes 13 arranged with an ion exchange membrane 11 formed of an anion exchange membrane constituting an electrolyte sandwiched therebetween. . As schematically shown in FIG. 2, the positive electrode 12 consists of three unit positive electrodes 12A to 12C, and the three unit positive electrodes 12A to 12C are arranged vertically at a predetermined interval. . 14 is a groove formed between each unit positive electrode. Similar to the positive electrode 12, the negative electrode 13 is also
The three unit negative electrodes 13A to 13C are arranged in a row in the width direction at a predetermined interval. 15 is a groove formed between each unit negative electrode. In this way, the unit positive electrodes 12A to 12C and the unit negative electrodes 13A to 13C are arranged to be orthogonal to each other with the ion exchange membrane 11 in between.

On the side surfaces of the unipolar current collector 20d and the bipolar current collectors 20a and 20b that are in contact with the positive electrodes 12, unit positive electrodes 12A to 12A are attached.
A plurality of grooves 21 having a U-shaped cross section and opening toward the positive electrode 12 are formed at equal intervals along the longitudinal direction of the electrode 12C. Each of these grooves 21 constitutes an oxidizing gas (air) supply path. In this embodiment, two of the gas supply paths 21... are connected to the groove 1.
It is now compatible with 4. In addition, the unipolar current collector 20
On the side surfaces of the C1 bipolar current collectors 20a and 20b that are in contact with the negative electrodes 13..., there are grooves with a U-shaped cross section that open toward the negative electrodes 13... along the longitudinal direction of the unit negative electrodes 13A to 13C. A plurality of 23... are formed at equal intervals. These grooves 23 each constitute a fuel gas (hydrogen) supply path. In this embodiment, the fuel gas supply path 23...
In this example, two of the gas supply passages correspond to the groove 15, and the space surrounded by the groove 15 and the fuel gas supply passage 23 constitutes the water absorbing body storage space 24. In this case, fuel gas is supplied from the upper fuel gas inlet 23a of the fuel gas supply path 23 toward the lower fuel gas outlet 23b (see FIG. 3). Similarly, the water absorbing body storage space 24... is also connected from the upper detection gas inlet 24a... to the lower detection gas outlet 24b.
The fuel gas is supplied as the detection gas in the direction of flow (see Fig. 3). Inside the water absorbent storage space 24...
When water is absorbed, the water-absorbing polymer 30 expands to such an extent that fuel gas does not pass through the space 24 and comes into contact with the ion exchange membrane 11 and the unit negative electrodes 13A to 13C.
... has been inserted.

The water-absorbing polymer 30 is made of polyacrylic acid-based, polyvinyl alcohol/maleic acid-based, or polyethylene oxide-based polymer. In this embodiment, dry polyacrylic acid polymer powder is made into a paste by absorbing sufficient moisture and is press-fitted into the water-absorbing body storage space 24 to form the water-absorbing polymer 30. Formed. Water is supplied to each water-absorbing polymer 30 from the suction channel 40 without water leakage. In addition, from the suction channel 40, the water-absorbing polymer 30.
An example of a structure for supplying water without leakage will be described in detail later.

FIG. 3 shows the negative electrode 13... side portions of the current collectors 20a, 20b, and 20c corresponding to the cells 1.0a to 10c in FIG. water supply system to the water-absorbing polymer 30... and the negative electrode 13...
It is a diagram schematically representing a schematic configuration of a fuel gas supply system to ... and a water content detection means.

In FIG. 3, parts not shown in FIG. 1 are the fuel gas supply means 50, the water content detection means 60, the water supply control device 70 and the control valve 71, and the water supply tank 100.

The fuel gas supply means 50 includes a fuel gas storage tank 51,
It is composed of a fuel gas supply duct 52 and a fuel gas exhaust duct 53. The fuel gas supply duct 52 includes a fuel gas inlet 23a of a fuel gas supply path constituted by grooves 23 formed in the current collectors 20a to 20c of each cell. 24a...) from the fuel gas storage tank 51.

The fuel gas exhaust duct 53 has a fuel gas outlet 23b...
・(Detected gas inlet 24b of water absorbent storage space 24...
The fuel gas discharged from the fuel tank (excluding the fuel tank) is discharged from a fuel gas discharge port (not shown).

The water supply channel 40 is a water supply tank 1-0 provided outside the battery.
0 via a control valve 71;
A plurality of water supply pipes 42 branch from 1 and run through the fuel gas supply duct 52 so as to be directly connected to the water absorbent polymer 30...
It is composed of...

An example of the structure of the connecting portion between the water supply pipes 42 and the water-absorbing polymers 30 is shown in FIG. As shown in FIG. 5, in this embodiment, the tip of the water supply pipe 42 is inserted into the water-absorbing polymer 30, and the water absorption pipe 42 is provided with a plurality of pores 43. Water is supplied from 43 into the water-absorbing polymer 30. When the water-absorbing polymers 30 expand due to water content, the pores 43 are closed by the expanded polymers 30, and the outflow of water from the pores 43 is stopped. According to this structure, there is no need for a special sealing member, and the water suction pipe 42
water leakage can be prevented. The length of the water absorption pipe 42 may be determined as appropriate depending on the water content of the water absorbent polymer 30.

The water content detection means 60 is basically the water absorbent storage space 24.
means for supplying a detection gas to the detection gas inlet 24a of the detection gas inlet 24a;
It is configured to include a gas detector 61 that detects gas flowing out from the detection gas outlet 24b. In this embodiment, since fuel gas is used as the detection gas, no special means for supplying the detection gas is provided. Further, in this embodiment, a connecting gas passage 63 is provided in order to use one gas detector 61 to detect the outflow of the detection gas from the plurality of water absorbing body storage spaces 24 . The connecting gas passage 63 includes a connecting gas passage main pipe 65 having a gas detection chamber 64 accommodating the gas detector 61 at its outlet, and a plurality of connecting gas passage main pipes 65 connecting the detected gas outlet 24b... and the connecting gas passage main pipe 65. Connecting gas pipe 66
..., and is configured to guide the gas flowing out from the plurality of detection gas outlet ports 24b into the gas detection chamber 64 in which one gas detector 61 is accommodated.

In the figure, the gas detection chamber 64 is shown in an open state, but the structure of the gas detection chamber 64 may be any structure as long as it allows the gas detector 61 to appropriately detect the gas. The gas supplied to the gas detection chamber 64 is processed as appropriate. Further, the connecting gas pipes 66... penetrate the fuel gas exhaust duct 53 in an airtight manner.

The gas detector 61 detects the presence and amount of gas flowing into the gas detection chamber 64 and outputs the result as a detection signal. The detection signal output from the gas detector 61 is input to the water supply control device 70 via the connection line 62. The operation of the water supply control device 70 will be explained later.

When the oxidizing gas is supplied to the positive electrodes 12 . . . and the fuel gas flowing out from the fuel gas storage tank 51 is supplied to the negative electrodes 13 .
A chemical reaction occurs with 1 and the battery starts generating electricity. In the battery of this embodiment, during power generation, the water-absorbing polymer 30 is filled in the water-absorbing body storage space 24 in an expanded state, so that fuel gas does not flow out through the water-absorbing body storage space 24.

Since the ion exchange membrane 11 is formed of an anion exchange membrane, as power generation progresses, water is generated at the negative electrode 13 by the reaction between the fuel and hydroxide ions. This water is the negative electrode 13.
It is absorbed by the water-absorbing polymer 30 through the end face of the water absorbent polymer 30. Further, when the water content of the ion exchange membranes 11... decreases, the water absorbed by the water absorbing polymers 30... is absorbed into the ion exchange membranes 11 due to the difference in osmotic pressure, and water replenishment is performed. As the power generation progresses further, the rate of decrease in the water content of the ion exchange membranes 11 increases, so the amount of water that the ion exchange membranes 11 absorb from the water-absorbing polymers 30 further increases.

The water stored in the water supply pipe 40 is absorbed by the water-absorbing polymer 30.
When the water-absorbing polymer 30 is no longer supplied to...
As the water content decreases, the water-absorbing polymers 30... begin to shrink, and the ion exchange membranes 11... and the water-absorbing body storage space 24...
A gap is formed between the detection gas inlet 24a and the detection gas outlet 24b to communicate with each other. The fuel gas supplied from the fuel gas supply duct 52 passes through this gap, and a portion of the fuel gas flows out into the connecting gas passage 63 as a detection gas.

When the gas detector 61 detects the detection gas, the gas detector 6
The water supply control device 70 is activated by the detection signal from 1,
The control valve 71 is opened in response to a control signal output from the water supply control device 70, and water supply to the water-absorbing polymers 30 is started. When water supply starts, water-absorbing polymer 30.
... expands again.

As the water supply to the water-absorbing polymers 30 progresses and the water content within each water-absorbing polymer reaches a saturated state, the water-absorbing polymers 3
0... completely fills the water absorbing body storage space 24..., so the flow of the detection gas passing through the water absorbing body storage space 24... stops, and the output of the detection signal from the gas detector 61 also stops. be done. The water supply control device 70 stops outputting the control signal in response to the stop of the detection signal, and the control valve 71 is closed. This completes the water supply to the water-absorbing polymer ~30.

Note that the operation mode of the water supply control device 70 is not limited to the above example. For example, the control valve 71 may not be opened immediately after the detection signal is output, but the control valve 71 may be opened after a certain amount of time has elapsed. Further, the control valve 71 may be closed before the output of the detection signal from the gas detector 61 is stopped.

As described above, in the gas fuel cell of this embodiment, when the water content of the ion exchange membranes 11... decreases, water is replenished from the water absorbing polymers 30... to the ion exchange membranes 11... and the ion exchange membranes 11... The moist state of the membrane 11 is maintained,
Furthermore, when the water content of the water-absorbing polymers 30... decreases, water is replenished from the water supply tank 100 provided outside the battery to the water-absorbing polymers 30.... Therefore, the wet state of the ion exchange membrane can be maintained without storing a large amount of water in the fuel cell as in the conventional case. In addition, since the water-absorbing polymer 30... is placed in contact with the ion exchange membrane 11..., it is possible to solidify the water that is refilled to the ion exchange membrane 1..., which greatly reduces the sealing area. In addition, the direction of battery installation, portability, and handling can be greatly improved.

In the gas fuel cell of this embodiment, the fuel gas supplied to the positive electrodes 12 is used as the detection gas, but it goes without saying that a detection gas supply means may be provided separately. In that case, the gas outlet of the separately provided detection gas storage device and the detection gas inlet 24a may be directly connected through a duct or the like.

Furthermore, although the gas fuel cell of this embodiment uses an anion exchange membrane for the ion exchange membranes 11 constituting the electrolyte, a cation exchange membrane may be used for the ion exchange membrane 11.

In that case, the water produced by the reaction is transferred to the positive electrode 12.
Since the water-absorbing polymer 30 is formed on the side of the ion exchange membrane 11 on the side of the positive electrode 12, it is sufficient to fill the groove 21 that does not face the positive electrode. Note that in this case, it is necessary to use a combustible gas sensor as the gas detector 61.

In addition, in a battery that generates a large amount of power, water-absorbing polymers may be placed in contact with both sides of the ion-exchange membrane 11 (positive electrode side and negative electrode side) in order to quickly replenish the ion-exchange membrane with water.

Furthermore, in the above embodiment, one gas detector is provided for a plurality of water absorbing polymers, but it is also possible to provide an individual gas detector for each water supply polymer, or one gas detector is provided for each cell. It is also possible to provide individual gas detectors.

Further, in the above embodiment, the water content of the ion exchange membrane is detected using gas flow, but the water content may be detected using other known detection means. for example,
A humidity sensor or the like can also be used as the moisture content detection means.

[Effects of the Invention] According to the invention of claim 1, when a water absorbing body made of a water absorbing polymer is placed in contact with an ion exchange membrane and a water supply channel is connected to the water absorbing body in a manner that prevents water leakage, ion exchange is possible. When the water content of the membrane decreases, water is replenished from the water-absorbing polymer and the ion exchange membrane can be kept in a moist state.

Moreover, even if the water-absorbing polymer absorbs water from the water supply channel, it will no longer contain water once it reaches a saturated state, so no water will leak out, so it solidifies the water that is refilled to the ion-exchange membrane. This has the advantage that the number of sealing points can be significantly reduced, and the orientation of battery installation, portability, and handling properties can be greatly improved.

Further, according to the invention of claim 2, since the water absorbing body is disposed so as to be in contact with the electrode that generates water among the positive electrode and the negative electrode and the surface of the ion exchange membrane on the side of the electrode, a portion of the generated water is can be absorbed by the water absorber, and the generated water can be used to replenish the ion exchange membrane, saving the amount of water supplied to the water absorber.

According to the third aspect of the invention, the water content of the water absorbing body is detected by the water content detection means, and when the water content of the water absorbing body becomes low, the control valve is opened to supply water to the water absorbing body. Water can be supplied automatically, backflow from the water supply canal can be prevented, and portability and handling can be greatly improved.

According to the invention of claim 4, there is an advantage that the water content of the water absorbing body can be easily detected without arranging a sensor inside the cell.

According to the invention of claim 5, since the gas (oxidant gas, fuel gas) supplied to the electrode (positive electrode or negative electrode) is used as the detection gas, a special gas supply means is required to detect the water content. There is no need to use it, and the manufacturing cost of the liquid fuel cell can be reduced and the structure of the liquid fuel cell can be simplified.

According to the invention of claim 6, when the battery includes a plurality of cells, the water content of the water absorber can be detected with one gas detector, which simplifies the structure of the liquid fuel cell. can do.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a portion where a plurality of cells constituting the gaseous fuel cell of this embodiment are connected in series by a current collector, and FIG. 2 is a perspective view showing the cells of the gaseous fuel cell of this embodiment. FIG. 3 is a diagram schematically showing the configuration of the gas fuel cell of this embodiment and a water supply tank provided outside the cell, and FIG. 4 is a diagram schematically showing the structure of the gas fuel cell of this embodiment. FIG. 5 is a cross-sectional view showing a connection state between a water supply pipe and a water-absorbing polymer that constitute a battery, FIG. 5 is a schematic cross-sectional view of an example of a conventional gas fuel cell, and FIG. 6 is a schematic cross-sectional view of an example of a conventional gas fuel cell. FIG. 2 is an exploded perspective view specifically illustrating a joining structure between an exchange membrane and a frame that constitutes a fuel gas supply path. 1... Gaseous fuel cell, 2,11... Ion exchange membrane,
3.12... Positive electrode, 4, 13... Negative electrode, 5... Oxidizing gas supply path, 6... Fuel gas supply path, 7... Water trap section, 8... Gasket, 9 ···flame,
10 a to 10 c --- cell, 20 a to 20 d
-... Current collector, 21, 23... Groove, 24... Water absorbing body storage space, 30... Water absorbing body, 40... Water supply channel, 50
... Fuel gas supply means, 51 ... Fuel gas storage tank, 52 ... Fuel gas supply duct, 53 ... Fuel gas discharge duct, 60 ... Moisture content detection means, 61 ...
Gas detector, 63... Connecting gas passage, 64... Gas detection chamber, 70... Water supply control device, 71... Control valve,
100...Water tank. Figure Figure

Claims (6)

[Claims] (1) In a gas fuel cell comprising at least one cell in which a positive electrode to which an oxidant gas is supplied and a negative electrode to which a fuel gas is supplied are arranged with an ion exchange membrane constituting an electrolyte in between. A gaseous fuel cell characterized in that: a water absorbent made of a water absorbing polymer is disposed in contact with the ion exchange membrane; and a water supply channel is connected to the water absorbent in a manner that prevents water leakage. (2) The water absorbing body is arranged so as to be in contact with an electrode that generates water among the positive electrode and the negative electrode and a surface of the ion exchange membrane on the electrode side. Gaseous fuel cell. (3) a control valve that controls the water supply to the water supply channel according to a control signal; a water content detection device that detects the water content of the water absorbing body; and a control valve that controls the water content based on the detection signal from the water content detection device. The gas fuel cell according to claim 1 or 2, further comprising a water supply control device that controls a valve. (4) The water absorbing body is arranged in a water absorbing body storage space formed between the electrode and the ion exchange membrane, and the water absorbing body sufficiently supplies moisture to the ion exchange membrane in the water absorbing body storage space. In a possible state, the water absorbent is expanded so that gas does not flow therethrough, and the water content detection means is connected to a detection gas supply means that supplies detection gas from one end of the water absorbent storage space and the water absorbent storage space. The gaseous fuel cell according to claim 3, further comprising a gas detector that detects the detection gas exiting from the other end. (5) The gas fuel cell according to claim 4, wherein the detection gas supply means is a means for supplying gas to the electrode. (6) A plurality of cells are provided, the other end of the water absorbent storage space of each cell is connected by a connecting gas passage, and one of the gas detectors is disposed on the outlet side of the connecting gas passage. The gaseous fuel cell according to claim 4, characterized in that: