JP2000348753A - Fuel cell and its use method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell capable of easily processing water produced in a positive electrode and to provide its use method. SOLUTION: This fuel cell 10 is so structured that a negative electrode, a positive electrode and an electrolytic part arranged between the electrodes are interposed between first plates P1-P5 each having a groove part for oxygen gas used as an oxygen gas passage formed and second plates P2-P6 each provided with a groove part for hydrogen gas used as a hydrogen gas passage. The groove parts for oxygen gas are shaped into a form capable of passing the oxygen gas toward the peripheral part of the first plates P1-P5. Preferably, the groove parts for hydrogen gas of the second plates P2-P6 are also shaped into a form capable of passing hydrogen gas toward the peripheral parts of the second plates P2-P6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a fuel cell having a structure in which a positive electrode, a negative electrode, and an electrolytic portion are sandwiched between a pair of plates, and a method of using the same.

[0002]

2. Description of the Related Art In a fuel cell, after hydrogen as a negative electrode active material is brought into contact with a catalyst such as platinum (platinum) to dissociate it into electrons and hydrogen ions, the hydrogen ions are reacted with oxygen as a positive electrode active material. Water is obtained from the reaction mechanism. That is, in a fuel cell, an electromotive force is generated by the movement of electrons released from hydrogen. Based on such a principle, a chemical energy change can be directly converted into electric energy, so that the energy efficiency is extremely high as compared with other power generation methods. This means that the fuel cell has less energy loss than the internal combustion engine based on the Carnot cycle, and is useful as a battery of a motor for an electric vehicle as an alternative to the internal combustion engine. In a fuel cell, the exhaust gas is mainly water vapor, and harmful gases such as nitrogen compounds, hydrocarbons, and carbon monoxide are not emitted unlike an internal combustion engine. There is a demand for practical use of such electric vehicles.

Here, a schematic configuration of a fuel cell conventionally employed is shown in FIG. 7 and FIG. The fuel cell 6 shown in these figures is a so-called solid polymer type in which a solid polymer membrane 7 is employed as an electrolyte. Specifically, an ion exchange membrane 7 as a solid polymer membrane is interposed between a pair of plates 70 and 71 in a state where a negative electrode catalyst layer 7A and a positive electrode catalyst layer 7B are formed on both surfaces thereof, respectively. I have. Further, between the ion exchange membrane 7 and each of the plates 70 and 71, a negative electrode current collector 80 and a positive electrode current collector 81 are further disposed.

[0004] One of the plates 70 and 71 is provided with a hydrogen gas groove 70A serving as a flow path for supplying hydrogen gas as a negative electrode active material to the negative electrode catalyst layer 7A. Oxygen gas groove 70 serving as a flow path when oxygen gas as a positive electrode active material is supplied to positive electrode catalyst layer 7B.
B is provided. Each of the current collectors 80 and 81 is formed to be porous, and allows passage of hydrogen gas and oxygen gas. That is, the hydrogen gas from the hydrogen gas groove 70A passes through the negative electrode current collector 80 and reaches the negative electrode catalyst layer 7A, and the oxygen gas from the oxygen gas groove 71A passes through the positive electrode current collector 81 and It reaches the catalyst layer 7B. The negative electrode catalyst layer 7A is obtained by supporting a catalyst such as palladium on carbon powder. In the negative electrode catalyst layer 7A, hydrogen gas is dissociated into hydrogen ions and electrons. The hydrogen ions pass through the ion exchange membrane 7 to reach the cathode catalyst layer 7B, and the electrons pass from the anode current collector 80 via the external circuit 9 to the cathode catalyst layer 7B.
Reach At this time, electric energy due to the movement of the electrons is extracted in the external circuit 9. The cathode catalyst layer 7B is
For example, palladium and rhodium are co-supported on carbon powder. In this positive electrode catalyst layer 7B, hydrogen ions, electrons and oxygen gas react to generate water.

[0005]

SUMMARY OF THE INVENTION The fuel cell 6 having the above configuration
Then, it is necessary to treat the water generated in the positive electrode catalyst layer 7B. That is, if the generated water stays in the oxygen gas groove 71A of the plate 71, the supply of oxygen gas to the positive electrode is hindered. If the generated water stays in the positive electrode catalyst layer 7B or the positive electrode current collector 81, the positive electrode It obstructs the passage of oxygen gas and its reaction.

SUMMARY OF THE INVENTION The present invention has been made under the above circumstances, and has as its object to provide a fuel cell capable of easily treating water generated at a positive electrode and a method of using the same. I have.

[0007]

DISCLOSURE OF THE INVENTION In order to solve the above-mentioned problems, the present invention takes the following technical means.

That is, the fuel cell provided by the first aspect of the present invention provides a positive electrode, which reacts oxygen gas, which is a positive electrode active material, with hydrogen ions and electrons to generate water. A cathode that dissociates into hydrogen ions and electrons, and an electrolysis section that is disposed between these electrodes and that allows the transfer of hydrogen ions from the negative electrode to the positive electrode; And a second plate provided with an oxygen gas groove serving as a flow path for oxygen gas, wherein the first plate is provided with An oxygen gas supply means connected to the oxygen gas groove is provided at the center portion, and the oxygen gas groove is adapted to transfer oxygen gas introduced from the oxygen gas supply means to a peripheral portion of the first plate. Towards It is characterized in that it is formed in the form to be circulated.

In a preferred embodiment, the second
A hydrogen gas supply means connected to the hydrogen gas groove is provided at a central portion of the plate, and the hydrogen gas groove is configured to transfer hydrogen gas introduced from the hydrogen gas supply means to the second plate. Is formed in such a form as to be circulated toward the peripheral edge portion.

The positive electrode includes, for example, a positive electrode catalyst layer and a positive electrode current collector, and the negative electrode includes, for example, a cathode catalyst layer and a negative electrode current collector. Of course, as an electrode having both the function as a catalyst layer and the function as a current collector, an electrode corresponding to the catalyst layer and a electrode corresponding to the current collector may be integrally formed.

The positive electrode catalyst layer and the negative electrode catalyst layer may have a structure in which a catalyst is supported on a porous carrier, for example, or may be formed directly on the surface of the electrolytic portion.

The catalyst layer having the former configuration is formed by solidifying catalyst particles in which a catalyst is previously supported on carbon powder or the like to form a porous matrix. Alternatively, after forming a porous matrix by solidifying carbon powder or the like, the matrix may be impregnated with a solution containing a catalyst component and then heat-treated.

[0013] The catalyst layer having the latter structure is prepared by, for example, screen printing or the like using a paste or suspension of a carbon powder as a carrier supporting a catalyst with an organic solvent or a mixture of the catalyst and the carbon powder with an organic solvent. It is formed by applying to the electrolytic part by a technique and evaporating the solvent component. Further, a carbon thin film to be a catalyst layer may be formed on a water-repellent sheet made of a fluororesin or the like by a method such as screen printing and drying, and then this may be thermally transferred to an electrolytic portion to form a catalyst layer.

Since it is necessary to react oxygen gas with hydrogen ions and electrons in the positive electrode catalyst portion, the catalyst constituting the catalyst portion may be, for example, platinum, gold, silver, or the like.
Rhodium is used. On the other hand, since it is necessary to dissociate hydrogen gas into hydrogen ions and electrons in the negative electrode catalyst portion, for example, platinum, gold, nickel, tungsten carbide, or the like is used as a catalyst constituting the catalyst portion.

[0015] The positive electrode current collector has a function of passing oxygen gas to reach the positive electrode catalyst layer and supplying electrons to the positive electrode catalyst layer. On the other hand, the negative electrode current collector has a function of passing hydrogen gas to reach the negative electrode catalyst layer and collecting electrons generated in the negative electrode catalyst layer. For this reason, the negative electrode current collector and the positive electrode current collector are required to have appropriate porosity and be a good electronic conductor. Of course, it is also required to have excellent mechanical strength and to be hardly affected by the electrolyte. The constituent materials of the current collector satisfying such requirements include carbon-based materials (carbon powder such as carbon black, graphite, carbon fiber, etc.), nickel,
Nickel-chromium alloy, nickel-cobalt alloy, silver,
Titanium, tantalum, oxide semiconductors, and the like are given.

The electrolysis section contains an electrolyte that permits the transfer of hydrogen ions, such as a solid polymer,
Examples include an alkaline solution, a solution of a super strong acid or phosphoric acid, a carbonate, or a solid oxide.

The solid polymer is formed, for example, in the form of a film or a sheet to form an electrolytic portion. A polystyrene-based cation exchange membrane, for example, a perfluorosulfonic acid polymer is preferably used. This polymer exhibits proton conductivity when wetted with water, and protons (hydrogen ions) generated by dissociation of hydrogen gas in the negative electrode catalyst layer pass through the electrolytic portion by permeation in a hydrated state, and It is adapted to move to the catalyst layer.

Examples of the alkaline solution include potassium hydroxide solution. Examples of the super-strong acid solution include fluoroethanedisulfonic acid solution, difluoromethanedisulfonic acid solution, difluoromethanediphosphonic acid solution, trifluoromethanesulfonic acid solution, trifluoromethanesulfonic acid solution and trifluoromethanesulfonic acid solution. An ethanesulfonic acid solution, a tetrafluoroethanedisulfonic acid solution, a tetrafluoropropanesulfonic acid solution, or the like can be given.

The alkaline solution, the superacid solution or the phosphoric acid solution is used as an electrolytic part by impregnating and holding a powder such as silicon carbide in a porous matrix bound with a resin such as polytetrafluoroethylene.

Examples of the carbonate include sodium carbonate, potassium carbonate, lithium carbonate and the like. These may be used alone, or a plurality of kinds may be mixed and used as a mixed molten salt. The carbonate is mixed with, for example, lithium aluminate particles and hot-pressed at a temperature about 10 ° C. lower than the melting point of the carbonate, or impregnated into a lithium aluminate plate to form an electrolytic part. In this electrolysis part, the carbonate is melted by operating at a high temperature to become a carbonate ion conductor.

As the solid oxide, zirconium oxide,
Examples include calcium oxide, yttrium oxide, ytterbium oxide, scandium oxide, neodymium oxide, gadolinium oxide, and lanthanum oxide. Among these solid oxides, zirconium oxide is particularly preferably used, and zirconium oxide in zirconium oxide may be partially substituted with other solid oxide constituent atoms to form a solid solution.

The first plate and the second plate are:
A region that functions as a battery is defined between these plates, and not only is provided to secure the region, but also a groove is formed in each of the plates to be used when supplying oxygen gas or hydrogen gas. It is formed in a rectangular or circular shape by using a material having excellent heat resistance and high mechanical strength, for example, various metals and alloys (titanium, stainless steel, titanium alloy, and the like).

The groove formed in each plate is formed, for example, as a spiral extending continuously from the center of the plate to the peripheral portion, or as a plurality of individual grooves extending radially from the center to the peripheral portion. Is done. The gas flow path formed by the oxygen gas groove is preferably open at the peripheral portion of the first plate and communicates with the outside of the fuel cell. The gas flow path formed by the hydrogen gas groove is preferably used. Is preferably closed at the periphery of the second plate. In other words, while releasing oxygen gas to the outside of the fuel cell is not so problematic, releasing hydrogen gas to the outside of the fuel cell is not preferable from the viewpoint of safety. Need to be done. Note that in a configuration in which oxygen gas is released to the outside of the fuel cell, it is expected that water generated at the positive electrode will be eliminated accompanying the released oxygen gas.

Preferably, the inner surfaces of the hydrogen gas groove and the oxygen gas groove are subjected to a water-repellent treatment. As the water repellent treatment, for example, a method of coating a fluororesin is employed. Examples of the fluororesin include polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-ethylene copolymer, polyvinylidene fluoride, and tetrafluoroethylene-tetrafluoropropylene copolymer.

The hydrogen gas supply means and the oxygen gas supply means
For example, this is achieved by a pipe, and a propulsive force is applied by the pressure of a compressor or the like, and the gas is circulated in the pipe to supply hydrogen gas or oxygen gas to the groove of the first or second plate.

The fuel cell according to the present invention can be used as a fuel cell stack by stacking a plurality of fuel cells in series. In a fuel cell stack, the same plate can be shared between adjacent fuel cells. In this case, a groove for hydrogen gas is provided on one side of the shared plate, and a groove for oxygen gas is provided on the other side. Also, the hydrogen gas grooves of each plate are communicated with each other, and the oxygen gas grooves are communicated with each other.If hydrogen gas is supplied from one location, hydrogen gas flows through all the hydrogen gas grooves of each plate, and so on. Alternatively, if the oxygen gas is supplied from one location, the oxygen gas may flow through all the oxygen gas grooves of each plate. Further, the shared plate may be formed of a conductor and may be configured to conduct to both the positive electrode current collector of one fuel cell and the negative electrode current collector of the other fuel cell. In this configuration,
The electrons collected in the negative electrode current collector of the other fuel cell are supplied to the positive electrode current collector of one fuel cell through a shared plate, and the electrons are used to generate water in the positive electrode catalyst layer of one fuel cell. It will contribute to the reaction.

According to a second aspect of the present invention, there is provided any one of the above-described first aspects of the present invention.
There is provided a method of using one fuel cell, comprising rotating the fuel cell.

In the above-described fuel cell according to the first aspect of the present invention, at least the oxygen gas groove of the first plate is configured to extend from the center of the plate toward the peripheral edge. Therefore, the oxygen gas supplied to the oxygen gas groove portion flows from the center of the plate toward the peripheral portion. And when the fuel cell is rotated,
Due to the centrifugal force, a greater force acts on the oxygen gas toward the periphery of the plate. Further, water generated in the positive electrode tends to accumulate in the oxygen gas groove, but when the fuel cell is rotated, centrifugal force also acts on the water accumulated in the oxygen gas groove. That is, due to the action of the centrifugal force and the flow of the oxygen gas, the water collected in the oxygen gas groove flows along the groove. Moreover,
Since the centrifugal force acting on the water increases as the distance from the center of the first plate increases, and the flow rate of the oxygen gas also increases, the water in the groove surely reaches the peripheral edge of the first plate. Since the groove for oxygen gas can be configured to communicate with the outside of the fuel cell at the periphery of the first plate, this water is positively removed to the outside of the fuel cell. . Further, when the water repellent treatment is performed on the inner surface of the oxygen gas groove, since the resistance between water moving in the groove and the inner surface of the groove is reduced,
The elimination of water from the groove can be performed even better.

On the other hand, the hydrogen gas groove formed in the second plate can also be formed so as to extend from the center of the plate toward the peripheral edge. In this configuration, however, every corner of the hydrogen gas flow path is formed. Hydrogen gas can be spread well up to this point. In other words, the hydrogen gas is difficult to spread to the part farther from the center of the plate due to the greater pressure loss up to that part, but if the fuel cell is rotated, the hydrogen gas is generated by the centrifugal force. Propulsion is given,
Further, the greater the distance from the center, the greater the propulsive force is applied, so that the hydrogen gas can be spread to every corner of the hydrogen gas flow path.

In rotating the fuel cell,
Although a driving mechanism may be separately provided, it is preferable to use a rotating member or mechanism, if any, in the vicinity of the location of the fuel cell. For example, when a fuel cell is mounted on an automobile, the fuel cell is integrated or connected to a rotating member such as a drive shaft or a tire wheel of the automobile, and the fuel cell is operated together with the rotating member or in conjunction with the rotation of the rotating member. May be rotated. in this case,
The energy loss of the entire system including the fuel cell is smaller as compared with the configuration in which the drive mechanism is separately provided, and the efficiency of the entire system is not significantly reduced as compared with the case where the fuel cell is not rotated.

Other features and advantages of the present invention will become more apparent from the detailed description that follows.

[0032]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be specifically described below with reference to the drawings. 1 is an overall perspective view showing an example of a fuel cell stack comprising the fuel cell according to the present invention, FIG. 2 is a cross-sectional view of the fuel cell stack of FIG. 1, and FIG. 3 is an enlarged view of a region surrounded by a solid line in FIG. FIGS. 4 (a) and 4 (b) are views for explaining the form of the groove of the plate constituting the fuel cell of the present invention, and FIG. 5 is FIG.
FIG. 4 is an enlarged perspective view of a main part of a joint pipe as a means for supplying hydrogen gas or oxygen gas to the plate shown in FIG. In the present embodiment, a polymer electrolyte fuel cell will be described as an example.

As shown in FIG. 1 and FIG. 2, the fuel cell stack 1 has a plurality of bolts B in a state in which a plurality of fuel cells 10 sharing one plate between adjacent ones are arranged in series. , And is sandwiched between two end plates 1A and 1B.

Each fuel cell 10 is shown in FIGS.
As before, two plates P_m, P_{m + 1}(M is 1 to 5
Integer) and these plates P_m, P_{m + 1}Intervene between
Exchange membrane 2 as an electrolytic part, and this ion exchange membrane
2 and each plate P_n(N is an integer from 1 to 6, the same applies hereinafter)
A negative electrode current collector 3 or a positive electrode current collector 4 interposed between
As a gas supply means penetrating the center of each of the above members
And a joining pipe 5 of the above.

As shown in FIGS. 2 and 4, each plate _Pn is entirely formed of a disc made of a conductor such as titanium or stainless steel, and has a central portion penetrating in the thickness direction. Through holes 12 are provided.
Further, a plurality of bolt holes 11 are provided in the peripheral portion so as to be arranged at a constant interval in the circumferential direction.

The plate P ₁ located at the right end in FIG.
As shown in FIG. 4 (a), an oxygen gas groove 13 is provided on one surface Pa side in a spiral form in a direction opposite to the rotation direction of the fuel cell stack 1 (see FIG. 1). ing. The oxygen gas groove 13, starting 13a along with leading to the through-hole 12, terminating 13b is open to the outside of the plate P _1.

The plate P ₆ located at the left end in FIG.
4B, the rotation direction of the fuel cell stack 1 (the direction of arrow A in the figure) is on the other surface Pb side, as is clearly shown in FIG.
The groove 14 for hydrogen gas is provided in the form of a spiral swirl in the opposite direction. The oxygen gas groove 14 has a starting end 14a.
Is connected to the through hole 12 and the terminal end 13b is closed. In the state of the fuel cell 10, the plate P ₁
And the plate P ₆ , when viewed in the axial direction, each groove 1
The starting ends 13a and 14a of the plates 3 and 14 are fixed to face each other with the axes of the plates P ₁ and P ₆ interposed therebetween.

The other plates P _{2 to} P ₅ are used commonly by the adjacent fuel cells 10, and are provided with an oxygen gas groove 13 in the form shown in FIG. On the other surface Pb side, a hydrogen gas groove 14 having the form shown in FIG. 4B is provided. In this case, the starting end 13a of the oxygen gas grooves 13 of each plate P ₂ to P _5, the starting end 4a of the hydrogen gas groove 14, the plate P ₂ to P ₅
Are provided so as to be opposed to each other with the axis of.

Although not shown in the drawing, the inner surfaces of the grooves 13 and 14 are subjected to a water-repellent treatment using a fluororesin or the like.

The ion exchange membrane 2 has a circular sheet shape as a whole, and is provided with a negative electrode catalyst layer 20 and a positive electrode catalyst layer 21 on both surfaces, respectively, as best seen in FIG. In addition, a through hole 2 through which the joining pipe 5 is inserted is provided at a central portion of the ion exchange membrane 2, and a peripheral portion thereof is
A plurality of bolt holes 22 into which the bolts B are inserted are provided.

The ion exchange membrane 2 has proton conductivity and selectively allows hydrogen ions to pass therethrough. As such an ion exchange membrane 2, for example, a perfluorosulfonic acid polymer which is a polystyrene-based cation exchange membrane is employed. This polymer exhibits conductivity when wetted with water, and the hydrogen ions pass through in a hydrated state.

The anode catalyst layer 20 is a porous layer composed of, for example, catalyst particles having platinum supported on the surface of carbon particles, and is capable of passing hydrogen molecules and hydrogen ions. In the anode catalyst layer 20, the supplied hydrogen gas is dissociated into hydrogen ions and electrons. On the other hand, the positive electrode catalyst layer 21 is, for example, a porous layer composed of catalyst particles in which platinum and rhodium coexist and are supported on the surface of carbon particles, and is capable of passing oxygen molecules. In the positive electrode catalyst layer 21, hydrogen ions react with oxygen and electrons to generate water.

The positive electrode current collector 3 is provided outside the fuel cell 10 including the positive electrode current collector 3 (the negative electrode current collector 4 of the adjacent fuel cell 10).
And from outside the fuel cell stack 1)
It is necessary to supply the electrons to the cathode catalyst layer 20 and to pass the oxygen gas so that the supplied oxygen gas reaches the cathode catalyst layer 20. For this reason, for example, the porous body is made of a carbon-based material (carbon powder such as carbon black, graphite, carbon fiber, etc.), nickel, a nickel-chromium alloy, a nickel-cobalt alloy, silver, titanium, tantalum, an oxide semiconductor, or the like. Is formed as Among these, a carbon-based material is particularly preferably used.

The negative electrode current collector 4 collects the electrons dissociated from the hydrogen gas in the negative electrode catalyst layer 21, and the outside of the fuel cell 10 including the negative electrode current collector 4 (the positive electrode current collector 3 of the adjacent fuel cell 10, It is necessary to make it possible to take out the hydrogen gas so that the supplied hydrogen gas can reach the negative electrode catalyst layer 21. Formed by material.

Around the positive electrode current collector 3 and the negative electrode current collector 4
Represents the ion exchange membrane 2 and each plate P as shown in FIG.
_iAnd the adjacent plate P_m,
P_{m + 1}Gasket 3 to improve sealing between
0 and 40 are provided. The gaskets 30, 40
Although not clearly shown on the drawing, the current collector 3,
The openings 31 and 41 having the same area as 4 are provided.
It has a circular frame shape, and each bolt B is inserted.
Bolt holes 32 and 42 are provided.

The joining pipe 5 supplies oxygen gas to the oxygen gas groove 13 formed in each plate _Pn and supplies hydrogen gas to the hydrogen groove 14. More specifically, as shown in FIGS. 2 and 5, a pipe 50 for feeding oxygen gas (air) and a pipe 51 for feeding hydrogen gas are joined. Each of the pipes 50 and 51 includes curved portions 50b and 51b and flat portions 50c and 51c, and has a semicircular hollow cross section. The pipes 50 and 51 are connected to each other by the flat portions 50c and 5
1c, they are joined together, and the joining pipe 5 has a circular shape having two hollow sections. On the curved surfaces of the pipes 50 and 51, at regular intervals,
Flow holes 50a and 51a penetrating in the radial direction are provided. These flow holes 50a, 51a are
Are formed so as to correspond to the starting ends 13a and 14a of the grooves provided in each plate _Pn . That is, the gas flowing through the pipes 50 and 51 is supplied to the grooves 13 and 14 via the communication holes 50a and 51a.

The fuel cell stack 1 having the above configuration
Is usually used by rotating the joint pipe 5 in the direction of the arrow indicated by the symbol A in FIGS. That is, while the fuel cell stack 1 is rotated, air or hydrogen gas containing oxygen gas flows through each of the pipes 50 and 51 constituting the joint pipe 5 (see FIGS. 2 and 3). At this time, the flow holes 5 of the pipes 50 and 51
Oxygen gas or hydrogen gas is supplied to the oxygen gas groove 13 to the hydrogen gas groove 14 via the holes 0a and 51a.

Since the hydrogen gas groove 14 is formed in a spiral shape (see FIG. 4B), the groove 14 is formed.
Supplied oxygen gas flows toward the periphery from the center of the plate P ₂ to P _6. At this time, since the fuel cell stack 1 is rotated, centrifugal force is applied to the hydrogen gas. Moreover, as the distance is large portion from the center of the plate P ₂ to P _6, a larger centrifugal force is applied, and from the inner surface of the groove portion 14 is water-repellent treatment, each plate P ₂ to P ₆ Hydrogen gas can be satisfactorily spread to a portion relatively far from the center of the device. Then, part of the hydrogen gas in the hydrogen gas groove 14 passes through the negative electrode current collector 3 and reaches the negative electrode catalyst layer 20. In the anode catalyst layer 20, hydrogen gas is dissociated into hydrogen ions and electrons (reaction formula (1) below).

[0049]

Embedded image

The electrons generated during this reaction are collected on the negative electrode current collector 3, and the electrons are usually transferred to the positive electrode current collector 4 of the adjacent fuel cell 10 sharing the negative electrode current collector 3. Supplied (see FIG. 2). In addition, hydrogen ions generated during the reaction in the anode catalyst layer 20 pass through the ion exchange membrane 2 in a hydrated state (reaction formula (2) below), and move to the cathode catalyst layer 21 of the same fuel cell 10.

[0051]

Embedded image

On the other hand, the oxygen gas groove 13 has a spiral shape, and the terminal end 13b has a plate P _1.
Since it is open to the outside of the fuel cell 10 in the periphery of the to P _5, the oxygen gas supplied to the groove portion 13 flows toward the end 13b which is set on the periphery of the plate P ₁ to P _5, the It is discharged from the terminal end 13b.

As described above, in normal use, the fuel cell stack 1 is rotating, and the oxygen gas groove 13
Is subjected to a water-repellent treatment, the oxygen gas flows along the surface of the groove 13 for oxygen gas having a reduced flow resistance while the centrifugal force is applied to the plates P _{1 to} P _5.
Will flow toward the periphery of. At this time, a part of the oxygen gas reaches the cathode catalyst layer 21 through the cathode current collector 4. The positive electrode catalyst layer 21 further includes plates P ₂ to
Electrons are supplied from the negative electrode current collector 3 of the adjacent fuel cell 10 or the outside of the fuel cell stack 1 sharing P _5, and hydrogen ions dissociated in the negative electrode current collector 3 via the ion exchange membrane 2 Supplied. In this way oxygen gas,
In the cathode catalyst layer 21 to which the electrons and the hydrogen ions are supplied, they react to generate water (reaction formula (3) below).

[0054]

Embedded image

Incidentally, water generated in the positive electrode catalyst layer 21 tends to collect in the hydrogen gas groove 13. In the present embodiment, since the fuel cell stack 1 is rotated and used, centrifugal force acts on the water in the groove 13.
For this reason, the water on which the centrifugal force equal to or more than the predetermined value acts due to the rotation, spirals along the groove 13 to form the plates P ₁ to P ₁ .
Moves toward the peripheral portion of P _5. And ultimately,
It is eliminated to the outside of the plate P ₁ to P ₅ (the fuel cell 10). Further, since the inner surface of the groove 13 is subjected to a water-repellent treatment to reduce the surface resistance against the movement of water,
Due to the effect of the smaller centrifugal forces, the water is displaced and eliminated. As described above, in the fuel cell stack 1 (fuel cell 10) of the present embodiment, the water generated in the positive electrode catalyst layer 21 can be preferably removed.

As described above, the fuel cell having the above configuration
In the pond stack 1, the negative electrode current collector 3 of one fuel cell 10
The collected electrons are usually collected on the same plate P_Two~ P_FiveTo
It is supplied to the positive electrode current collector 4 of the adjacent fuel cell 10 to be shared.
You. Then, the most downstream in the electron flow direction (the plate P
₆Side) of the fuel cell 10 located on the
The collected electrons flow through an external circuit (not shown)
(Plate P ₁Side) located fuel cell
It is supplied to 10 positive electrode current collectors 4. That is, the fuel cell
In the stack 1, electrons are in a certain direction as a whole.
(Plate P₁From plate P₆Side)
From the downstream fuel cell 10 to the most upstream fuel cell 10,
So that the electrons can be circulated through the circuit
I have. At this time, take out energy in the external circuit
It is made to use.

In this embodiment, each of the plates P ₁ to P ₁
The fuel cell 10 or the fuel cell stack 1 in which the groove portions 13 and 14 of P ₆ are formed in a spiral shape has been described. However, as the groove shape of each plate, for example, the shape shown in FIG. 6 can be adopted. . In the plate P ₁ to P ₆ shown in the figure, a plurality of individual grooves 13A extending linearly toward the peripheral portion (14A) is formed from the center, as a whole groove is a radial form. Even in such a groove configuration, the supplied oxygen gas and hydrogen gas, and further, water generated on the positive electrode side are suitably removed by centrifugal force due to rotation of the fuel cell stack (fuel cell). Further, in the groove form of the plate shown in FIG.
A form in which some or all of the plurality of individual groove portions 13A (14A) are branched on the way, or a plurality of individual groove portions 13A (1A).
A form in which part or all of 4A) is bent in the middle may be adopted.

[Brief description of the drawings]

FIG. 1 is an overall perspective view illustrating an example of a fuel cell stack including a fuel cell according to the present invention.

FIG. 2 is a cross-sectional view of the fuel cell stack of FIG.

FIG. 3 is an enlarged view of a region surrounded by a solid line in FIG.

4A is a plan view of a plate constituting the fuel cell of the present invention, and FIG. 4B is a bottom view thereof.

FIG. 5 is an enlarged view of a main part of a joining pipe as a means for supplying hydrogen gas or oxygen gas to the plate shown in FIG. 4;
It is the perspective view which was cross section.

FIG. 6 is a plan view of a plate showing a different form of a groove formed in the plate.

FIG. 7 is a cross-sectional view illustrating an example of a conventional fuel cell.

8 is an exploded view of the fuel cell of FIG.

[Explanation of symbols]

1 (as a gas supply means) the fuel cell stack 10 fuel cell 2 ion exchange membrane (as an electrolyte portion) 20 cathode catalyst layer 21 negative electrode catalyst layer 3 cathode collector 4 the anode current collector 5 junction pipe P ₁ to P ₆ plate

Claims (7)

[Claims] 1. A cathode for dissociating hydrogen gas as a negative electrode active material into hydrogen ions and electrons, a positive electrode for reacting oxygen gas as a positive electrode active material with hydrogen ions and electrons to generate water, and between the electrodes. And an electrolytic unit that allows the transfer of hydrogen ions from the negative electrode to the positive electrode, a first plate provided with an oxygen gas groove that forms an oxygen gas flow path, and a hydrogen gas flow A fuel cell sandwiched between a second plate provided with a hydrogen gas groove constituting a passage, wherein a central portion of the first plate includes oxygen connected to the oxygen gas groove. A gas supply unit is provided, and the oxygen gas groove is formed in such a form that the oxygen gas introduced from the oxygen gas supply unit is caused to flow toward the peripheral portion of the first plate. the above 1
A fuel cell, wherein the fuel cell communicates with the outside of the plate. 2. A hydrogen gas supply means connected to the hydrogen gas groove is provided at a central portion of the second plate, and the hydrogen gas groove is provided with hydrogen introduced from the hydrogen gas supply means. 2. The fuel cell according to claim 1, wherein the fuel cell is formed in a form in which gas flows toward a peripheral portion of the second plate. 3. 3. The plate according to claim 1, wherein at least one of the oxygen gas groove and the hydrogen gas groove is formed in a spiral shape extending continuously from a center of the plate toward a peripheral edge of the plate. Fuel cell. 4. The plate according to claim 1, wherein at least one of the groove for oxygen gas and the groove for hydrogen gas comprises a plurality of individual grooves extending radially from the center of the plate toward the peripheral edge. Fuel cell. 5. The fuel cell according to claim 1, wherein at least one of the inner surfaces of the oxygen gas groove and the hydrogen gas groove is subjected to a water-repellent treatment. . 6. A method of using a fuel cell according to claim 1, wherein the fuel cell is rotated. 7. The fuel cell is mounted on a vehicle, and the fuel cell is integrated or connected to a rotating member of the vehicle, and the fuel cell is integrated with the rotating member or in conjunction with the rotation of the rotating member. The method of using the fuel cell according to claim 6, wherein the fuel cell is rotated.