JP2010160937A - Fuel cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a downsized fuel cell in which fuel supply to a fuel electrode and oxidizer supply to an oxidizer electrode can be made efficient, and output density per volume can be improved. <P>SOLUTION: As for the fuel cell, respective single cells 4 are pinched by a sheet-like fuel supply sheet part 5 and an oxidizer supply sheet part 6 having flexibility, and can be bent at a coupling part 7 between the two-dimensionally arranged respective single cells 4. In the fuel supply sheet part 5, since fuel moves from a flow passage 14A of a first flow passage F1 by capillary flow in a porous structure in the flow passages 15A, 16C, 17A, 18A, respective flow passages are never blocked by air bubbles or the like. Moreover, in the oxidizer supply sheet part 6, since the flow passages 24A, 22A, 23, 20A forming a fourth flow passage F4 by a groove form a three-dimensional flow passage as a communication flow passage, compared with a planar flow passage layout, an oxidizer can be supplied more efficiently via the shortest and the optimal route by respective regions on the single cells 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell capable of increasing power density and a method for manufacturing the same.

  A fuel cell is a power generator that generates power when fuel and an oxidant are supplied. Since a fuel cell can normally use air as an oxidant, it can continuously generate power by continuously supplying and replacing the fuel. For this reason, fuel cells are attracting much attention because they can be used not only as stationary power sources but also as portable power sources.

  In general, when a fuel cell is used as a stationary power source or the like, hydrogen or a gas containing hydrogen is used as a fuel. On the other hand, when a fuel cell is used as a portable power source, it is necessary to generate power for a long time with a certain volume that can be carried. Therefore, the fuel is a liquid fuel having a high energy density per volume. This is more advantageous than the gas described above.

  It is also possible to construct a system in which a fuel cell is equipped with a reformer that reforms liquid fuel into hydrogen, and hydrogen is generated from the liquid fuel and supplied as fuel. However, since the entire fuel cell system becomes complicated, it is considered that it is easier to directly supply liquid fuel to the fuel cell in order to reduce the size of the fuel cell system.

  Conventionally, as a fuel cell to which liquid fuel is directly supplied, for example, a direct methanol fuel cell using a mixture of methanol and water as a fuel has been disclosed (for example, Japanese Patent Application Laid-Open No. 11-510311). Gazette) and patent document 2 (Japanese Patent Laid-Open No. 6-188008).

  Here, FIG. 11 is a diagram schematically showing a direct methanol fuel cell in which a power generation cell 100 including a fuel electrode 103, an oxidant electrode 102, and an electrolyte membrane 101 is laminated in a housing 116. Hereinafter, a description will be given with reference to FIG.

  The direct methanol fuel cell is formed by laminating a power generation cell 100 including a fuel electrode 102, an oxidant electrode 103, and an electrolyte membrane 101 in a housing 116. The operation of this direct methanol fuel cell will be described. First, fuel obtained by mixing methanol and water is supplied to the fuel introduction path 108 from a fuel tank (not shown) by a supply means such as a supply pump. The fuel supplied to the fuel introduction path 108 is supplied to the fuel electrode chamber 106 formed in the separator 105 in the direction indicated by the arrow 110. The fuel supplied into the fuel electrode chamber 106 penetrates into the fuel electrode 103 and reacts to generate protons (hydrogen ions), electrons, and carbon dioxide. Usually, a porous material is used as the material of the fuel electrode 103, and the reaction of the fuel electrode 103 occurs in a layer in which a catalyst near the interface between the fuel electrode 103 and the electrolyte membrane 101 is supported.

  Protons generated at the fuel electrode 103 pass through the electrolyte membrane 101 from the fuel electrode 103 and move to the oxidant electrode 102, and electrons flow from the fuel electrode 103 via an external circuit (not shown) to the oxidant electrode 102. Flowing into. This electron is used as the output of the battery. On the other hand, carbon dioxide is discharged from the fuel electrode 103 through the fuel electrode chamber 106 together with unreacted fuel.

  Further, oxygen is supplied to the oxidant electrode chamber 104 formed in the separator 105 in the direction indicated by the arrow 111, and oxygen diffuses from the oxidant electrode chamber 104 into the oxidant electrode 102. The oxygen reacts with protons diffused from the fuel electrode 103 to generate water. The generated water is normally converted into water vapor and discharged from the oxidant chamber 104 together with unreacted oxygen from the outlet side in the direction indicated by the arrow 112. In this example, oxygen is used as the oxidizing agent, but it can also be supplied by air containing oxygen.

  By the way, in the conventional direct methanol fuel cell, as shown in FIG. 11, when the power generation cells 100 are stacked, the fuel and the oxidant are placed in the very narrow fuel chamber 106 and the oxidant chamber 104 formed in the separator 105. Must be supplied. In order to stack the power generation cell 100 in a smaller housing, the fuel chamber 106 and the oxidant chamber 104 are further narrowed. Therefore, in order to supply the fuel and the oxidant to the power generation cell 100, more supply capability is provided. A supply means such as a pump is required.

  Therefore, the power required for driving the supply means such as a pump is consumed, so that the output that can be used from the fuel cell is substantially reduced, which hinders miniaturization of the fuel cell. Further, if the forcible supply means such as a pump is eliminated, the supply efficiency of the oxidant is lowered, which causes a decrease in the output of the fuel cell.

Japanese National Patent Publication No. 11-510311 JP-A-6-188008

  SUMMARY OF THE INVENTION An object of the present invention is to provide a small-sized fuel cell that can improve the efficiency of the supply of fuel to the fuel electrode and the supply of oxidant to the oxidant electrode and improve the output density per volume.

In order to solve the above problems, a fuel cell according to the present invention includes a fuel electrode that generates cations and electrons from supplied fuel, and a cation from the fuel electrode that is disposed so as to face the fuel electrode. A plurality of single cells in which a permeating electrolyte membrane and an oxidant electrode arranged to face the electrolyte membrane and reacting with the cation permeated through the electrolyte membrane and a supplied oxidant are stacked;
A fuel supply sheet portion disposed to face the fuel electrode of the single cell and having a flow path for supplying the fuel to the fuel electrode;
An oxidant supply sheet portion disposed so as to face the oxidant electrode of the single cell and having a flow path for supplying the oxidant to the oxidant electrode;
A first array part in which a plurality of the single cells are continuously arrayed by a flexible connecting part connecting at least one of the fuel supply sheet part or the oxidant supply sheet part; and in the direction of the stacking A plurality of adjacent single cells arranged have at least one of the fuel supply sheet part and the second array part sharing at least one of the oxidant supply sheet part.

  According to the fuel cell of the present invention, the fuel supply sheet portion or the oxidant supply sheet portion can be bent at the flexible connecting portion of the first arrangement portion, so that it matches the shape of the place to be stored. It is possible to realize an optimal storage form. Further, in the second arrangement portion, the plurality of adjacent single cells share the fuel supply sheet portion or the oxidant supply sheet portion, so that the size can be reduced when the plurality of single cells are stacked. Therefore, it is possible to improve the power density per volume in the fuel cell.

  In one embodiment, the fuel supply sheet portion and the oxidant supply sheet portion are joined around the single cell while sandwiching the single cell.

  According to the fuel cell of this embodiment, it is not necessary to individually perform fine processing for sealing on the side surface of the single cell, and it is not necessary to insert the single cell into a housing or the like. Therefore, the cut out single cells can be arranged as they are in the first and second arrangement portions, and the manufacturing process can be simplified.

  Further, in the fuel cell according to an embodiment, the fuel supply sheet portion and the oxidant supply sheet portion are electrically connected to either the fuel electrode or the oxidant electrode of the single cell at a location where the fuel supply sheet portion and the oxidant supply sheet portion are joined around the single cell. Wiring for connection is provided.

  According to the fuel cell of this embodiment, the fuel supply sheet part is not exposed to the outside of the fuel supply sheet part and the oxidant supply sheet part, and the wiring connected to the fuel electrode or oxidant electrode of the single cell is exposed. And it can arrange | position inside an oxidizing agent supply sheet | seat part.

Moreover, in the fuel cell of one embodiment, the first wiring that electrically connects the oxidant electrodes of the two adjacent single cells,
A second wiring for electrically connecting the fuel electrodes of the two adjacent single cells;
At least one of the fuel electrode of one unit cell of the two adjacent unit cells and the third wiring that electrically connects the oxidant electrode of the other unit cell is the first array. It arrange | positions along the said connection part of a part.

  According to the fuel cell of this embodiment, while maintaining the flexibility of the connecting portion, the first to third wires connect the fuel electrode and the oxidant electrode of the two adjacent single cells. A desired electrical connection can be made.

In the fuel cell of one embodiment, the fuel supply sheet portion is
Having a plurality of fuel supply sheet lamination members laminated in the direction of lamination,
The plurality of fuel supply sheet laminated members are
Including a flow path portion penetrating in the direction of the lamination and the flow path portion is formed of a hollow or porous material,
A flow path portion made of a porous material of the plurality of fuel supply sheet laminate members communicates to form a first flow path for supplying the fuel to the fuel electrode;
A hollow flow path portion of the plurality of fuel supply sheet laminated members or a flow path portion made of a porous material communicates to form a second flow path for discharging the discharge from the fuel electrode.

  According to the fuel cell of this embodiment, in the first flow path of the fuel supply sheet portion, the fuel moves by capillary flow in the porous structure, so that it is stable without using liquid feeding means such as a pump. Fuel can be supplied. Furthermore, since the first flow path is formed by a flow path portion that penetrates a plurality of stacked fuel supply sheet stacking members in the stacking direction, the first flow path can be a three-dimensional flow path. Compared with the road layout, the fuel can be efficiently supplied to each region of the single-cell anode through a shorter optimum path.

  Further, the second flow path is also formed by communicating the flow path portions of the plurality of fuel supply sheet lamination members, so that it can be a three-dimensional flow path, compared to a planar flow path layout. Thus, the exhaust from each region of the single-cell fuel electrode can be efficiently discharged by a shorter optimum route.

  In one embodiment, the fuel supply sheet laminate member has a fluid impermeable portion adjacent to the flow path portion, and the fluid impermeable portion is filled with a filler. The fuel and the exhaust from the fuel electrode cannot permeate.

  According to the fuel cell of this embodiment, the fuel supply sheet laminated member in which the fluid non-permeable portion and the flow path portion adjacent to the fluid non-permeable portion are formed, the sheet-like porous material is filled with the filler. It can be produced simply by introducing.

  In the fuel cell of one embodiment, at least a part of the first flow path is separated from the second flow path by the fluid non-permeable portion of the fuel supply sheet stacking member.

  According to the fuel cell of this embodiment, not only can the fuel electrode discharge, particularly carbon dioxide, be efficiently discharged by the second flow path, but also the flow of the discharged flow of fuel in the first flow path. Can be inhibited. Therefore, the supply efficiency of the fuel to the fuel electrode by the first flow path can be increased, and the output density of the single cell can be increased.

In the fuel cell of one embodiment, the first channel is
In the stacking direction, the fuel supply sheet stacking member is disposed upstream of the fuel supply sheet stacking member at one end on the fuel electrode side and has a supply suppressing structure that suppresses the flow of the fuel.

  According to the fuel cell of this embodiment, since the flow of the fuel in the first flow path is suppressed by the supply suppressing structure arranged in the first flow path, The pressure drop along the fuel flow direction can be suppressed, the fuel can be distributed in the first flow path, and the fuel can be supplied uniformly by the entire single cell.

In one embodiment, the fuel cell includes a plurality of adjacent single cells arranged in the stacking direction,
Furthermore, it has a fuel flow path that communicates each first flow path of each fuel supply sheet portion disposed opposite to each single cell on the upstream side of the supply suppression structure,
The fuel passage is closed at one end in the stacking direction.

  According to the fuel cell of this embodiment, fuel can be supplied from the fuel passage to the first flow path of the plurality of adjacent single cells, and the amount of fuel supplied to the first flow path of each single cell can be increased. The use efficiency of the supplied fuel for power generation can be further improved by equalization.

In the fuel cell of one embodiment, the fuel supply sheet portion is
A third flow path for supplying water for diluting the fuel supplied to the first flow path to the first flow path;
The third flow path is
The fuel supply sheet stacking member at one end on the fuel electrode side joins the first flow path on the upstream side.

  According to the fuel cell of this embodiment, water can be supplied from the third flow path that joins the first flow path, and the fuel supplied to the first flow path can be diluted. The fuel can be stored in the fuel tank in a high concentration state. Therefore, when the fuel cell is operated with the same tank capacity, the fuel cell can be operated for a longer time than when the fuel diluted to the optimum concentration from the beginning is used.

  In the fuel cell of one embodiment, the 3rd channel which the above-mentioned fuel supply sheet part has is connected over a plurality of single cells.

  According to the fuel cell of this embodiment, water for fuel dilution can be supplied from the third flow path communicating between the plurality of single cells to the first flow path of each single cell. Further, for example, when water collected from the fifth flow path (flow path for discharging water generated at the oxidizer electrode) of each single cell is passed through the third flow path, each single cell Even if there is a variation in the amount of water collected from the water, since the third flow path communicates with each single cell, the collected water can be efficiently used in the whole of the plurality of single cells.

In the fuel cell of one embodiment, the second flow path is
The first array portion communicates with at least one of the plurality of single cells of the second array portion and communicates with the outside of the fuel supply seat portion.

  According to the fuel cell of this embodiment, the second exhaust gas such as carbon dioxide discharged from the fuel electrode of each single cell arranged two-dimensionally or three-dimensionally is communicated around the plurality of single cells. Can be discharged out of the area of each single cell arranged two-dimensionally or three-dimensionally through the shortest path from the flow path. This can prevent a decrease in output of each single cell.

In the fuel cell of one embodiment, the oxidant supply sheet portion is
Having a plurality of oxidant supply sheet laminate members laminated in the direction of lamination,
The plurality of oxidant supply sheet laminated members are:
Including a flow path portion penetrating in the direction of the lamination and the flow path portion is formed of a hollow or porous material,
A hollow flow path portion of the plurality of oxidant supply sheet laminated members or a flow path portion made of a porous material communicates to form a fourth flow path for supplying an oxidant to the oxidant electrode. ,
A hollow flow path portion of the plurality of oxidant supply sheet laminated members or a flow path portion made of a porous material communicates to form a fifth flow path for discharging the effluent from the oxidant electrode. Yes.

  According to the fuel cell of this embodiment, the fourth flow path of the oxidant supply sheet portion is formed by a flow path portion that penetrates a plurality of stacked oxidant supply sheet lamination members in the stacking direction. A three-dimensional flow path can be formed, and the oxidant can be efficiently supplied to each region of the oxidant electrode of the single cell with a shorter optimal path than in the planar flow path layout.

  In addition, the fifth flow path can be formed as a three-dimensional flow path because the flow path portions of the plurality of oxidant supply sheet laminated members are formed in communication with each other. In comparison, the waste from each region of the oxidizer electrode of the single cell can be efficiently discharged by a shorter optimum route.

Moreover, in the fuel cell of one embodiment, the oxidant supply sheet laminated member is
The fluid non-permeating part is adjacent to the flow path part, and the fluid non-permeating part is filled with a filler so that the oxidant and the effluent from the oxidant electrode cannot permeate.

  According to the fuel cell of this embodiment, the oxidation in which the fluid non-permeable portion and the flow path portion adjacent to the fluid non-permeable portion are formed simply by introducing a filler into the sheet-like porous material. An agent supply sheet laminated member can be produced.

  In the fuel cell according to the embodiment, at least a part of the fourth flow path is separated from the fifth flow path by the fluid non-permeable portion of the oxidant supply sheet stacking member.

  According to the fuel cell of this embodiment, not only can the discharge (water) of the oxidant electrode be efficiently discharged by the fifth flow path, but also the flow of this discharge can flow out of the oxidant in the fourth flow path. Inhibiting the flow can be suppressed. Therefore, the supply efficiency of the oxidant to the oxidant electrode by the fourth channel can be increased, and the output density of the single cell can be increased.

In the fuel cell of one embodiment, the fourth flow path is
The first array part and the second array part communicate with each other between the plurality of single cells and communicate with the outside of the oxidant supply sheet part.

  According to the fuel cell of this embodiment, the oxidant (air) is supplied from the fourth flow path around the plurality of single cells arranged two-dimensionally or three-dimensionally to the oxidant electrode of each single cell. Can be supplied by the shortest route. In addition, from the outside of each single cell region arranged two-dimensionally or three-dimensionally, through the fourth flow path three-dimensionally connected around each single cell, the region of the single cell Ventilation through the outside can be secured by multiple routes. For this reason, it can prevent that an oxidizing agent (air) stagnates around a single cell, and the supply of oxygen to each single cell falls, and the output reduction of each single cell can be prevented.

  In the fuel cell according to the embodiment, the fifth flow path may include the third flow path at a joint portion where the fuel supply sheet portion and the oxidant supply sheet portion around the single cell are joined. It communicates with the flow path.

  According to the fuel cell of this embodiment, the effluent (water) generated at the oxidant electrode is collected through the fifth flow path, supplied to the fuel electrode side through the third flow path, and used for fuel dilution. can do.

In the fuel cell of one embodiment, the fifth flow path is
The plurality of unit cells communicate with each other in at least one of the first array section or the second array section.

  According to the fuel cell of this embodiment, since the fifth flow path communicates with each single cell, even if the amount of discharge (water) at the oxidant electrode of each single cell varies, The amount of water that can be collected in the fifth channel can be stabilized. Therefore, the water for fuel dilution can be stably supplied from the fifth channel to the third channel.

In the fuel cell manufacturing method of one embodiment, a material layer containing a filler is formed on the convex portion of the transfer substrate,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is Transferred to a sheet-like member,
The region of the sheet-like member on which the convex portions are overlapped is filled with the filler so that the region becomes a fluid non-permeable portion through which the fuel and the discharge from the fuel electrode cannot permeate. Forming a flow path part that is adjacent to the part and through which the fuel and the discharge from the fuel electrode can pass,
A substantially monolithic laminated structure comprising a plurality of the sheet-like members on which the flow path part and the fluid non-permeation part are stacked, and at least one communication flow path communicating with the flow path part. The body fuel supply sheet portion is formed.

  According to the fuel cell manufacturing method of this embodiment, unlike the case where the porous channel is formed by packing the porous material into the channel groove formed in the substrate, the porous channel and the channel There is no gap between the fluid impermeable portion and the wall surface defining the flow path portion. Therefore, the fluid does not permeate more than the permeability coefficient of the porous material through the gap at the interface between the flow channel portion made of the porous material and the flow channel wall.

  In one embodiment of the method for manufacturing a fuel cell, the sheet-like member is formed of a porous material that allows fluid to pass through the convex portion of the transfer substrate on which the material layer containing the filler is formed. When the material containing the filler is transferred onto the sheet-like member, the porous material is impregnated with the filler by annealing.

  According to the manufacturing method of the fuel cell of this embodiment, the filler can be sufficiently distributed in the porous structure of the sheet-like member as compared with the case where the material layer containing the filler is transferred to the region only by pressing. And leakage of fuel from the flow path can be reliably suppressed.

In the fuel cell manufacturing method of one embodiment, a material layer containing a filler is formed on the convex portion of the transfer substrate,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is Transferred to a sheet-like member,
The region of the sheet-like member on which the convex portions are overlapped is filled with the filler, and the region becomes a fluid non-permeable portion through which the discharge from the oxidant and the oxidant electrode cannot permeate. Forming a flow path section that is adjacent to the non-permeable section and through which the oxidant and the discharge from the oxidizer electrode can pass,
A substantially monolithic laminated structure comprising a plurality of the sheet-like members on which the flow path part and the fluid non-permeation part are stacked, and at least one communication flow path communicating with the flow path part. The body oxidant supply sheet portion is formed.

  According to the fuel cell manufacturing method of this embodiment, unlike the case where the porous channel is formed by packing the porous material into the channel groove formed in the substrate, the porous channel and the channel There is no gap between the wall surface defining the flow path. Therefore, the fluid does not permeate more than the permeability coefficient of the porous material through the gap at the interface between the flow channel portion made of the porous material and the flow channel wall.

  In one embodiment of the method for manufacturing a fuel cell, the sheet-like member is formed of a porous material that allows fluid to pass through the convex portion of the transfer substrate on which the material layer containing the filler is formed. When the material containing the filler is transferred onto the sheet-like member, the porous material is impregnated with the filler by annealing.

  According to the fuel cell manufacturing method of this embodiment, the filler is contained in the porous structure of the sheet-like member as compared with the case where the material layer containing the filler is transferred to the region of the sheet-like member only by pressing. The fuel leakage from the flow path can be reliably suppressed.

  In one embodiment of the fuel cell manufacturing method, the convex portion of the transfer substrate is pressed against the material layer of the material substrate on which the material layer containing the filler is formed, and the filler is applied to the convex portion. The containing material is transferred, and a material layer containing the filler is formed on the convex portion of the transfer substrate.

  According to the fuel cell manufacturing method of this embodiment, the material layer containing the filler can be easily laminated only on the convex portion of the transfer substrate.

  In the fuel cell manufacturing method of one embodiment, when the single cell is sandwiched between the fuel supply sheet portion and the oxidant supply sheet portion and joined around the single cell, the fluid impermeability is prevented by annealing. The fuel supply sheet part and the oxidant supply sheet part are bonded together by impregnating the joining region between the adjacent fuel supply sheet part and the oxidant supply sheet part.

  According to the fuel cell manufacturing method of this embodiment, the filler-impregnated region can be formed in the joint region between the fuel supply sheet portion and the oxidant supply sheet portion. Thereby, while seat parts are joined, it can control that fuel etc. leak along the interface between seat parts.

  In the fuel cell manufacturing method of one embodiment, when the single cell is sandwiched between the fuel supply sheet portion and the oxidant supply sheet portion and joined around the single cell, the fluid impermeability is prevented by annealing. The side surface of the unit cell, the fuel supply sheet unit, and the oxidant supply sheet are impregnated between the fuel supply sheet unit or the oxidant supply sheet unit adjacent to the side surface of the unit cell. Paste the parts together.

  According to the method for manufacturing a fuel cell of this embodiment, the side surface of the single cell, the fuel supply sheet portion, and the oxidant supply sheet portion can be bonded together, and at the interface between the side surface of the single cell and the sheet portion. It can suppress that fuel etc. leak along.

  According to the fuel cell of the present invention, the fuel supply sheet portion or the oxidant supply sheet portion can be bent at the flexible connecting portion of the first arrangement portion, so that it is optimal for the shape of the place to be stored. Can be realized. Further, in the second arrangement portion, the plurality of adjacent single cells share the fuel supply sheet portion or the oxidant supply sheet portion, so that the size can be reduced when the plurality of single cells are stacked. Therefore, it is possible to improve the power density per volume in the fuel cell.

1 is a schematic plan view showing a first embodiment of a fuel cell according to the present invention. It is typical sectional drawing which shows the said 1st Embodiment. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 13 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 14 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 15 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 16 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 17 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the fuel supply sheet | seat laminated member 18 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the single cell 4 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the oxidizing agent supply sheet | seat laminated member 20 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the oxidizing agent supply sheet | seat laminated member 21 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the oxidizing agent supply sheet | seat laminated member 22 with which the said 1st Embodiment is provided. It is a typical top view which shows the shape of the oxidizing agent supply sheet | seat laminated member 24 with which the said 1st Embodiment is provided. It is typical sectional drawing which shows the three-dimensional connection of the single cell in the modification of the said embodiment. It is typical sectional drawing which shows the serial connection form of the adjacent single cell in the modification of the said embodiment. It is typical sectional drawing which shows the parallel connection form of the adjacent single cell in the modification of the said embodiment. It is typical sectional drawing which shows the connection form of the fuel supply path in the modification of the said embodiment. It is a figure which shows an example of the output result of a fuel cell when it produces electric power using the fuel cell of the said embodiment. It is a figure which shows another example of the output result of a fuel cell when it produces electric power using the fuel cell of the said embodiment. It is a figure which shows another example of the output result of a fuel cell when it produces electric power using the fuel cell of the said embodiment. It is typical sectional drawing which shows 2nd Embodiment of the fuel cell of this invention. It is B-B 'sectional drawing of FIG. 8A. It is C-C 'sectional drawing of FIG. 8A. It is D-D 'sectional drawing of FIG. 8A. It is a typical top view which shows 3rd Embodiment of the fuel cell of this invention. It is sectional drawing which shows the E-E 'cross section of FIG. 9A. It is sectional drawing which shows the F-F 'cross section of FIG. 9A. It is sectional drawing which shows the G-G 'cross section of FIG. 9A. It is sectional drawing which shows the H-H 'cross section of FIG. 9A. It is a top view which shows the structure where the several single cell 44 arrange | positioned two-dimensionally in the said 3rd Embodiment couple | bonded together. It is process sectional drawing which shows 1 process of 4th Embodiment which is a manufacturing method of the fuel supply sheet | seat part with which the fuel cell of this invention is provided. It is process sectional drawing which shows 1 process of the said 4th Embodiment. It is process sectional drawing which shows 1 process of the said 4th Embodiment. It is a figure which shows typically the direct type | mold methanol fuel cell by which the electric power generation cell provided with the fuel electrode, the oxidizing agent electrode, and the electrolyte membrane was laminated | stacked in the conventional housing.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are denoted by the same reference numerals, and description thereof will not be repeated. In addition, dimensional relationships such as length, size, and width in the drawings are changed as appropriate for clarity and simplification of the drawings, and do not represent actual dimensions.

(First embodiment)
FIG. 1A is a schematic plan view showing a first embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing the first embodiment. 2A to 2G are schematic plan views showing the shapes of the fuel supply sheet lamination members 13 to 18 included in the first embodiment. 3A to 3D are schematic plan views illustrating the shapes of the oxidant supply sheet lamination members 20 to 24 included in the first embodiment. Hereinafter, the fuel cell according to the first embodiment will be described with reference to FIGS. 1A, 1B, 2A to 2G, and 3A to 3D.

  The fuel cell according to the first embodiment has a fuel electrode 1 that generates cations and electrons from supplied fuel, and is disposed so as to face the fuel electrode 1 so that cations from the fuel electrode 1 can pass therethrough. A plurality of unit cells 4 each including an electrolyte membrane 2 and an oxidant electrode 3 that is disposed so as to face the electrolyte membrane 2 and reacts with the cation that has passed through the electrolyte membrane 2 and the supplied oxidant are provided. .

  In addition, the fuel cell according to the first embodiment is arranged to face the fuel electrode 1 of the single cell 4 and includes a plurality of flow paths (first flow paths F1) for supplying fuel to the fuel electrode 1. The fuel supply sheet portion 5 in which the flow path is formed and the flow path (fourth flow path) for supplying the oxidant to the oxidant electrode 3 are disposed so as to face the oxidant electrode 3 of the single cell 4. An oxidant supply sheet portion 6 having a plurality of flow paths including F4) is provided. The first flow path F1 will be described later with reference to FIGS. 2A to 2F. The fourth flow path F4 will be described later with reference to FIGS. 3A to 3D.

  Moreover, in this 1st Embodiment, the adjacent single cell 4 has connected the fuel supply sheet | seat part 5 and the oxidizing agent supply sheet | seat part 6 with the flexible connection part 7. FIG. Thereby, the several single cell 4 is arrange | positioned two-dimensionally. Furthermore, by laminating the plurality of single cells 4 arranged two-dimensionally, it is possible to arrange them three-dimensionally.

  In this embodiment, the fuel supply sheet unit 5 and the oxidant supply sheet unit 6 are both connected to the adjacent unit cell 4, but only one of the fuel supply sheet unit 5 and the oxidant supply sheet unit 6 is connected. The single cells 4 can be two-dimensionally arranged even if they are connected between the adjacent single cells 4 and the other is not connected between the adjacent single cells 4. Further, the single cells 4 arranged two-dimensionally can be stacked to easily arrange the single cells 4 three-dimensionally. When only the fuel supply sheet portion 5 is connected between the adjacent single cells 4 and the single cells 4 are two-dimensionally arranged, it is necessary to separately form a flow path for transporting fuel to the adjacent single cells 4. The fuel can be easily fed through the connected fuel supply sheet portion 5.

  Further, two-dimensionally adjacent single cells 4 are connected by the oxidant supply sheet portion 6 and a fuel supply path 50A is arranged in the three-dimensionally stacked direction as will be described later with reference to FIG. By connecting to the fuel supply sheet portion, the fuel supply path to each single cell 4 can be shortened, the decrease in fuel supply pressure can be suppressed, and fuel can be supplied to each single cell more uniformly. Become.

  A porous material such as carbon paper, a sintered body of carbon, a sintered metal such as nickel, a foam metal, or porous silicon can be used for the base of the fuel electrode 1 and the oxidant electrode 3 of the single cell 4. As the catalyst of the fuel electrode 1, for example, platinum-gold, platinum-osmium, platinum-rhodium, or other alloys such as a platinum-ruthenium alloy can be used.

  Further, the same catalyst as that of the fuel electrode 1 can be used for the oxidant electrode 3, and the material of the oxidant electrode 3 and the material of the fuel electrode 1 may be the same. The electrolyte membrane 2 may be an organic material or an inorganic material as long as it is a proton-conductive heat-resistant and acid-resistant material. For example, a sulfonic acid group-containing perfluorocarbon having an organic fluorine-containing polymer as a skeleton (Nafion 117 ( DuPont) (registered trademark)) can be used.

  The electrolyte membrane 2 only needs to have a proton-conducting function, and may be one in which the electrolyte membrane is embedded in another base material. The membrane electrode assembly comprising the electrolyte membrane 2, the fuel electrode 1, and the oxidant electrode 3 of the fuel cell of the present invention can be obtained by a conventionally known method. For example, the electrolyte membrane obtained as described above 2, the fuel electrode 1 and the oxidant electrode 3 can be manufactured by hot press bonding. Furthermore, this invention does not limit the structure and material of the single cell 4 to said form, and it cannot be overemphasized that it may be comprised with another material.

  The size of each single cell 4 is about 5 mm to 25 mm on a side in a typical example in this embodiment, but in this invention, the size of the single cell is the fuel supply sheet portion 5 or the oxidizer. The size is relatively determined by the size of the flow path formed in the supply sheet 6 and the space between the stacked single cells 4, and the size is not particularly limited to the above dimensions.

  As the liquid fuel supplied to the fuel electrode 1, a mixture of methanol and water can be used. The fuel is not limited to this, and a hydrocarbon-based organic fuel such as ethanol or dimethyl ether can be used instead of methanol.

Further, air that originally contains oxygen as an oxidizing agent can be used as it is, but oxygen itself can also be used. The fuel supplied into the fuel supply sheet unit 5 reaches the fuel electrode 1 and reacts to generate cations (H ⁺ ), electrons, and carbon dioxide as exhaust gas. The cation (H ⁺ ) reaches the oxidant electrode 3 via the electrolyte membrane 2. On the other hand, the electrons are guided from the fuel electrode 1 to the oxidant electrode 3 via an external circuit (not shown). Further, exhaust gas such as carbon dioxide generated at the fuel electrode 1 passes through the fuel supply sheet unit 5 and is discharged out of the fuel supply sheet unit 5.

On the other hand, air as an example of the oxidant introduced from the outside into the oxidant supply sheet unit 6 diffuses into the oxidant electrode 3, and the cation (H ⁺ ) and electrons from the fuel electrode 1 in the oxidant electrode 3. Reacts with water to produce water vapor, and this water vapor is discharged out of the oxidant supply sheet portion 6.

  In the fuel cell according to this embodiment, each single cell 4 is sandwiched by a thin and flexible sheet-like fuel supply sheet portion 5 and an oxidant supply sheet portion 6 in which a flow path is formed. It is possible to bend at the connecting portion 7 between the single cells 4 arranged in a regular manner. Further, even when three-dimensionally stacked, the entire battery can be deformed as schematically shown in FIG. 4, so that it can be optimally stored according to the shape of the place to be stored. .

  4 indicates one power generation unit in which the single cell 4 is sandwiched between the fuel supply sheet portion 5 and the oxidant supply sheet portion 6. Furthermore, as shown in FIG. 1A, a space 8 can be secured around the connecting portion 7 between the single cells 4 as a supply path for an oxidant and a discharge path for water vapor as a reaction product.

  Therefore, as in the conventional example shown in FIG. 11, the oxidant can be supplied more efficiently to the stacked single cells 4 than when the supply path is secured in only one direction. . In addition, even when supplying the oxidant to each single cell 4 using a supply means such as a pump, the supply path to each single cell 4 is shortened, reducing the load on the supply means and suppressing power consumption. Can do. Therefore, it is possible to improve the power density per volume in the small fuel cell when the plurality of single cells 4 are stacked.

  Furthermore, in this embodiment, as shown in FIG. 1B, the fuel supply sheet portion 5 and the oxidant supply sheet portion 6 of each single cell 4 are joined around the single cell 4 while sandwiching each single cell 4. Yes. Here, it is necessary to seal the side surface 4A of each unit cell 4 so that the fuel on the fuel electrode 1 side does not leak from the side surface of the unit cell 4 and diffuse to the oxidant electrode 3, but in this embodiment, it is thin. Utilizing the flexibility of the fuel supply sheet portion 5 and the oxidation supply sheet portion 6, the fuel supply sheet portion 5 and the oxidation supply sheet portion 6 wrap around the side surfaces of the unit cells 4 and join them. Reference numeral 55 denotes a sealing resin.

  As a result, the side surface 4A of the single cell 4 can be easily sealed, so there is no need to individually perform fine processing for sealing on the side surface 4A of each single cell 4 or to insert a housing or the like. Since the cut out single cells 4 can be arranged as they are, the manufacturing method is simplified and the cost can be reduced.

  Further, by joining the fuel supply sheet portion 5 and the oxidant supply sheet portion 6, the connecting portion 7 between the single cells 4 can be thinned. Therefore, while improving the flexibility of the connection part 7, the space 9 connected to the said space 8 can be ensured around the connection part 7 between each single cell 4, and supply of the oxidizing agent to each single cell 4 is possible. Can be made more efficient.

  Further, in this embodiment, as shown in FIG. 1B, the connecting portion 10 where the fuel supply sheet portion 5 and the oxidant supply sheet portion 6 are joined around the single cell 4 is arranged along the oxidant supply sheet portion 6. In addition, a wiring 12A for electrical connection with the oxidant electrode 3 is provided. The wiring 12A electrically connects the oxidant electrodes 3 of the adjacent single cells 4. Further, the connecting portion 10 may include a wiring 11 </ b> A for electrically connecting the fuel electrodes 1 of the adjacent single cells 4 along the fuel supply sheet portion 5.

  For example, in this embodiment, the wiring 12A shown in FIG. 2F is an example of a wiring for connecting to the fuel electrode 1, and the wiring 12B shown in FIG. 3A is an example of a wiring for connecting to the oxidant electrode 3. The wiring 12 </ b> A in FIG. 2F is provided on the fuel supply sheet stacking member 18. Moreover, the wiring 12B of FIG. 3A is provided in the oxidant supply sheet laminated member 20.

  Thus, the wiring is bent in the stacking direction and is electrically connected to the fuel electrode 1 and the oxidant electrode 3 of each single cell 4 without exposing the wiring in the space 9 around the connecting portion 7 serving as a passage for the oxidant or the like. Therefore, the wirings 12A and 12B can be easily pulled out to the wiring 11A of the connecting portion 10.

  As a result, while maintaining flexibility in the connecting portion 7 and without exposing the wirings 12A, 12B, and 11A to the space 9 around the connecting portion 7 serving as a passage for oxidizing agent, water vapor, etc., the adjacent unit The fuel electrode 1 or the oxidant electrode 3 of the cell 4 can be electrically connected.

  In the example shown in FIG. 1B, the two-dimensionally arranged single cells 4 and 4 can be electrically connected in parallel by wirings 12A and 11A. Furthermore, in the example shown in FIG. 5A, the two-dimensionally arranged single cells 4 and 4 can be electrically connected in series with the wirings 11A, 12A, and 12B covered with the connection portion 10B. In the example of FIG. 5A, the two-dimensionally arranged single cells 4, 4 are stacked and arranged three-dimensionally. As shown in FIG. 5A, in this example, the unit cells 4 and 4 adjacent to each other in the stacking direction are arranged to face each other so that the fuel electrode 1 faces each other, and the respective fuel supply sheet portions 5 face each other. The pair of fuel supply sheet portions 5 arranged opposite to each other share the fuel supply sheet stacking member 14.

  Furthermore, as shown in FIG. 5B, the single cells 4 and 4 adjacent in the stacking direction can be easily electrically connected in series with the wirings 11C, 12A, and 12B covered with the connection portion 10C. In the example of FIG. 5B, unlike the example of FIG. 5A described above, the single cells 4 and 4 adjacent in the stacking direction are arranged in the same direction. In the example shown in FIG. 5B, an example in which the single cells 4 and 4 adjacent in the stacking direction are connected in series is shown. However, it is easy to connect the adjacent single cells 4 and 4 in parallel. Can understand.

  Next, the laminated structure of the fuel supply sheet portion 5 of the fuel cell of this embodiment will be described. The fuel supply sheet portion 5 shown in FIG. 1B is formed by laminating fuel supply sheet lamination members 13, 14, 15, 16, 17, and 18 shown in FIGS. 2A to 2F.

  As shown in FIG. 2A, the fuel supply sheet laminate member 13 has a flow path 13A formed of a through groove and a fluid non-passing portion 13B that partitions the flow path 13A. As shown in FIG. 2B, the fuel supply sheet laminate member 14 includes a through channel 14A formed of a porous material, a through channel 14C formed of a through groove, and the through channels 14A and 14C. Fluid non-passing part 14B. As shown in FIG. 2C, the fuel supply sheet laminate member 15 includes a through passage 15A formed of a porous material, a through passage 15C formed of a through groove, and the through passages 15A and 15C. A fluid non-passing portion 15B is defined. The porous material is a porous material through which the fuel or the discharge from the fuel electrode 1 can pass. On the other hand, the fluid non-passage portions 13B, 14B, and 15B cannot pass the fuel and the discharge from the fuel electrode 1.

  Further, as shown in FIG. 2D, the fuel supply sheet laminate member 16 includes a through channel 16A, 16C formed of a porous material, a through channel 16D formed of a through groove, and the through channel 16A, It has a fluid non-passing part 16B that partitions 16C and 16D. As shown in FIG. 2E, the fuel supply sheet laminate member 17 includes a through channel 17A formed of a porous material, a through channel 17C formed of a through groove, and the through channels 17A and 17C. It has a fluid non-passing part 17B. Further, as shown in FIG. 2F, the fuel supply sheet laminate member 18 has a through passage 18A formed of a porous material and a fluid non-passing portion 18B that partitions the through passage 18A. The fuel supply sheet stacking member 18 at one end in the stacking direction is disposed so as to face the fuel electrode 1. The porous material is a porous material through which the fuel or the discharge from the fuel electrode 1 can pass. On the other hand, the fluid non-passing portions 16B, 17B, and 18B cannot pass the fuel and the discharge from the fuel electrode 1.

The flow path 14A, the flow path 15A, the flow path 16C, and the flow paths 17A and 18A formed of the porous material communicate with each other in the stacking direction to form a first flow path F1 that supplies fuel to the fuel electrode 1. is doing. Further, the through-flow passages 13A, 14C, 15C, 16D, and 17C formed by the through-grooves communicate with the flow passage 18A formed of the porous material in the stacking direction, and the discharge (CO ₂ ), the second flow path F2 is formed.

  Further, the through flow path 16A formed of the porous material communicates with the through flow paths 17A and 18A formed of the porous material to form a third flow path F3. The third flow path F3 is a flow path for supplying water for diluting the fuel.

According to the first flow path F1 made of the porous material formed in the fuel supply sheet portion 5 as described above, the fuel introduced into the flow path 14A communicates by the absorption capacity and the capillary action of the porous structure. The fuel is introduced into the flow paths 15A, 16C, 17A, and 18A made of a porous material in order, and the fuel diffused in the flow path 18A reaches the fuel electrode 1 and reacts to generate cations (H ⁺ ) and electrons. it can.

  In the fuel supply sheet portion 5 of the fuel cell, the fuel is moved by the capillary flow in the porous structure in the flow paths 15A, 16C, 17A, and 18A from the flow path 14A of the first flow path F1. Each flow path is not blocked. Therefore, the fuel can be stably supplied without using a liquid feeding means such as a pump. Furthermore, since the flow paths 14A, 15A, 16C, 17A, and 18A forming the first flow path F1 form a three-dimensional flow path as a communication flow path, the flow path 14A, 15A, 16C, 17A, and 18A are more The fuel can be efficiently supplied to each region on the single cell 4 by a short optimum route.

  In this embodiment, as the fuel supply sheet lamination members 13 to 18 constituting the fuel supply sheet portion 5, for example, porous silicon, carbon paper, a sintered body of carbon, a sintered metal such as nickel, a porous polyimide resin, etc. A porous material having chemical resistance such as porous PTFE (polytetrafluoroethylene) can be used.

  The porous structure of the flow paths 14A, 15A, 16A, 16C, 17A, and 18A made of the porous material of each sheet laminated member may be a structure that induces capillary flow of fluid, and may be a fiber structure. Good. In order to easily induce capillary flow, those porous agents that have been subjected to a hydrophilic treatment are preferred.

  In a typical example in this embodiment, the thickness of the fuel supply sheet laminate members 13 to 18 is about 30 μm to 200 μm, and the pore diameter of the porous material is about 0.01 μm to 10 μm. Further, the width of the channel is, for example, about 10 μm to 200 μm in the channel 16C.

  In the present invention, the pore diameter of the porous material, which is the passage region, and the width of each flow path are relatively determined by the size of the single cell, the diffusion rate of the fuel supply sheet laminate member, etc. It is not limited to the above dimensions. In addition, the present invention is not limited to the number and layout of the flow paths to the embodiments shown in FIGS. 1A and 1B and FIGS. 2A to 2G, and these flow paths may be branched. Needless to say.

  In a more preferable example, the fluid non-permeable portions 13B, 14B, 15B, 16B, 17B, and 18B of the fuel supply sheet lamination members 13, 14, 15, 16, 17, and 18 constitute the first flow path F1. It is formed by filling the same structural portion as the porous material forming the flow paths 14A, 15A, 16C, 17A, and 18A. Thereby, each fuel supply sheet member 14, 15, 16, 17, 18 can define the flow paths 14A, 15A, 16A, 16C, 17A, 18A by the fluid non-permeable portions 14B, 15B, 16B, 17B, 18B. Thereby, the porous through-channels 14A to 18A can be easily formed simply by introducing the filler into the sheet-like porous material. As the filler, a resin such as PTFE (polytetrafluoroethylene), acrylic, or polyimide can be used.

  More preferably, the communication channel including the channel 18A formed in the fuel supply sheet stacking member 18 at one end in the stacking direction is from the channel 14A for supplying fuel to the channel 18A to the channels 15A, 16C, and 17A. A first flow path F1 that continues to the flow path, and a second flow path F2 that continues from the flow path 13A to the flow paths 14C, 15C, 16D, and 17C and discharges the fuel electrode 1 from the flow path 18A. The first flow path F1 and the second flow path F2 are separated.

  As a result, not only the discharge from the fuel electrode 1, particularly carbon dioxide, can be efficiently discharged from the second flow path F2, but also carbon dioxide stays in the flow path 18A and the fuel from the first flow path F1 flows. Inhibition of the flow can be suppressed, fuel supply efficiency to the fuel electrode 1 can be increased, and the output density of the single cell 4 can be increased.

  Here, in the state where the fuel supplied from the flow path 17A constituting the first flow path F1 and the carbon dioxide generated in the fuel electrode 1 are present in the flow path 18A, An equation indicating the balance of meniscus force formed at the interface between the fuel (liquid) and carbon dioxide (gas) is expressed as the following equation (1).

Pf = σ · cos (π−α) / d + Pg (1)
In equation (1), Pf is the pressure of the fuel, Pg is the pressure of carbon dioxide, σ is the surface tension, α is the angle between the meniscus and the inner wall of the micropore, and d is the inner diameter of the micropore. That is, the fuel can enter the fine holes up to the inner diameter of the value d satisfying the equation (1) when the fuel pressure is Pf. That is, in the vicinity of the flow path 17A where the fuel supply pressure is high, the fuel can permeate into the flow path 18A.

  On the other hand, since the flow path 17C side on the second flow path F2 side is opened and the pressure Pg of carbon dioxide is suppressed from increasing in the flow path 18A, the carbon dioxide is on the first flow path F1 side. Cannot flow backward to the vicinity of the flow path 17A. Further, in the vicinity of the flow path 17C on the second flow path F2 side, the fuel supply pressure is sufficiently low, so that the fuel is fine up to the inner diameter of the value d satisfying the expression (1) indicating the balance position of the meniscus. It is possible to prevent the fuel from entering the hole and discharging the fuel to the second flow path F2.

  In this embodiment, the flow paths 13A to 14C, 15C, 16D, and 17C constituting the second flow path F2 are formed by grooves formed in the fuel supply sheet stacking members 13, 14, 15, 16, and 17. However, it is needless to say that a porous material may be used as long as it has a transmittance that can maintain the pressure Pg of the formula (1) sufficiently low.

  Further, in this embodiment, the first flow path F1 includes a supply suppressing structure on the upstream side with respect to the flow path 18A formed in the fuel supply sheet stacking member 18 at one end in the stacking direction. That is, in this embodiment, the flow paths 15A and 16C have a sufficiently small cross-sectional area with respect to the upstream flow path 14A, and constitute a supply suppressing structure. Thereby, the pressure drop along the flow direction in the upstream flow path 14A is suppressed, and the fuel can be uniformly supplied to the entire single cell 4 through the flow path 15A and the flow path 16C of each single cell 4.

  The supply suppression structure may be configured by forming the flow paths 15A and 16C with a material that is less permeable to fuel than the material forming the flow path 14A. For example, when the channel 15A is made of a porous material, the channel 15A may be formed of a porous material having a lower transmittance than the porous material forming the channel 14A. However, in order to supply the fuel uniformly by the fuel electrode 1, it is preferable to form the flow paths 14A, 15A, and 16C with a porous material with little variation in local flow rate. Further, to reduce the permeation rate of the porous material, it can be achieved by reducing the pore diameter, but the pore diameter is relatively determined according to the film thickness and the pore diameter of the flow path 14A, is not particularly limited, For example, a film having a film thickness of about 1 μm to 30 μm and a porous material having a pore diameter of about 0.01 μm to 1 μm can be used. Preferably, the permeation speed of the flow path 15A is preferably lower than the permeation speed of the flow path 14A by, for example, about one to two orders of magnitude when the air permeability is measured by the Gurley tester method.

  Further, the permeation speed of the porous material in the flow path 15A of the fuel supply sheet laminate member 15 can be set to the permeation speed of the porous material in the flow path 14A by filling a part of the porous material with the filler. Can be reduced by one or two digits. In this case, it is not necessary to use a porous material different from the flow channel 14A as the flow channel 15A, and there is an advantage that the same porous material can be used for the flow channel 15A and the flow channel 14A. As the filler, a resin such as PTFE (polytetrafluoroethylene), acrylic, or polyimide can be used.

  More preferably, the first flow path F1 of the single cell 4 is adjacent to and shares the fuel supply sheet portion 5 in the flow path 14A on the upstream side of the flow path 15A of the supply suppression structure. The single channel 4 is connected to the first flow path F1. One end of the flow path 14 </ b> A of the connected first flow path F <b> 1 on the upstream side of the supply suppressing structure is closed by the single cell 4 arranged on the most downstream side of the connected single cells 4. According to this structure, the end in the flow path 14A of the single cell 4 is not directly connected to other locations in the fuel cell except that it is connected to the flow path 14A of the adjacent single cell 4. Further, the diffusion of fuel to the fuel electrode 1 of each single cell 4 is restricted by the flow path 15A of the supply suppression structure. Thereby, the fuel fills the flow path 14A, and the pressure drop in the first flow path F1 can be minimized.

  Then, the fuel can be supplied more uniformly from the flow path 15A facing the flow path 14A to the fuel electrode 1 of each single cell 4 little by little through the communication flow paths 16C, 17A, 18A of each single cell 4. At this time, as described above, since the fuel is not easily discharged from the flow path 18A to the flow path 17C on the second flow path F2 side, the fuel is discharged from the second flow path F2 in an unreacted state. The fuel supplied in each single cell can be reacted efficiently and without waste. That is, it is possible to further improve the utilization efficiency of the fuel supplied per unit area of each single cell for power generation.

  Further, in the structure in which the end of the flow path 14A of the first flow path F1 for supplying the fuel is closed, the supply pressure of the fuel in the flow path 14A is lower than in the case where the end of the flow path 14A is not closed. The fuel supply pressure in the vicinity of the flow path 17A on the first flow path F1 side of each unit cell 4 can be further increased. Therefore, when carbon dioxide generated in the fuel electrode 1 is discharged from the flow path 18A to the flow path 17C of the second flow path F2, the carbon dioxide is flowed from the flow path 18A to the first flow path F1 side. In the vicinity of 17A, the fuel supply from the flow path 17A to the flow path 18A is prevented from being hindered, and the fuel can be supplied more efficiently.

In general, the liquid fuel necessary for the reaction at the fuel electrode 1 is about several μl / min per unit area assuming, for example, a power generation of about 150 mW / cm ^{2 in a} fuel cell using methanol and water as fuel. is there. Therefore, even if more fuel is supplied, the excess fuel can be used to discharge the fuel filled in the vicinity of the fuel electrode unreacted, or it can diffuse through the electrolyte membrane and cause a decrease in output. Thus, the fuel utilization efficiency is further reduced. In other words, the reaction of the fuel electrode is not rate-determined by the amount of fuel supplied, and the reaction proceeds in a reaction-controlled state. Therefore, by providing the supply suppression structure as in this embodiment, it is possible to efficiently supply the fuel necessary for the reaction and continue the reaction with the minimum necessary supply.

  Next, FIG. 6 shows an example in which the flow paths 14A forming the first flow paths F1 of the fuel supply sheet portion 5 of each unit cell 4 adjacent in the stacking direction are connected. In this example, a fuel supply sheet stacking member 50 including a flow path 50A for sending fuel in the stacking direction is provided. The fuel supply sheet laminate member 50 includes a flow path 50A made of a porous material that can permeate fuel and a non-permeate portion 50B for fuel.

  A flow path 14A forming the first flow path F1 of each single cell 4, 4, 4, 4 is connected to the flow path 50A to form a communication flow path. As a result, one end of the flow path 50A is closed by the most downstream non-permeating portion 50B, and the fuel supplied from the flow path 50A passes through the flow path 50A and the first flow path F1 of each unit cell 4. The flow path 14A is filled, and the fuel can be supplied to each single cell 4 more uniformly. The flow path 14A of each single cell 4 connected to the flow path 50A in the stacking direction does not necessarily need to be connected to both sides of the flow path 50A, and is connected only to one side of the flow path 50A as shown in FIG. May be.

  Next, FIG. 7A shows an example of the output result of the fuel cell when power is generated using the fuel cell of the present embodiment. The output result of FIG. 7A is obtained by recording the output of a single cell 4 having a side of 23 mm using a 3M aqueous methanol solution as fuel. Here, a porous carbon material is used for the base of the fuel electrode 1 and the oxidant electrode 3 of the single cell 4, a platinum-ruthenium alloy is used for the catalyst of the fuel electrode 1, and platinum is used for the catalyst of the oxidant electrode 3. Is used. As the electrolyte membrane 2, Nafion 117 (manufactured by DuPont: registered trademark) is used. Hydrophilic porous PTFE (polytetrafluoroethylene: manufactured by Sumitomo Electric Fine Polymer Co., Ltd.) was used for the fuel supply sheet laminate members 13 to 18 constituting the fuel supply sheet portion 5. The average pore diameter of this hydrophilic porous PTFE is 0.45 μm. Further, acrylic resin is used as a filler for the fluid non-permeable portions 13B, 14B, 15B, 16B, 17B, and 18B of the fuel supply sheet laminate members 13 to 18. By the fuel supply sheet portion 5, the fuel is introduced without using a liquid feeding means such as a pump by the absorption power and capillary action of the porous PTFE, and is supplied to the fuel electrode 1 so that the single cell 4 can be operated. In addition, the carbon dioxide generated in the fuel electrode 1 is communicated with the flow paths 13A, 14C, 15C, 16D, and 17C formed by through grooves formed in the fuel supply sheet laminate members 13, 14, 15, 16, and 17. It is confirmed that the gas is discharged through the flow path F2.

  Therefore, according to the fuel cell of this embodiment, the fuel can be efficiently supplied without waste without using a pump or the like, and a high output can be obtained even if it is downsized.

  Furthermore, in this embodiment, the first flow path F1 is upstream of the flow path 18A formed in the fuel supply sheet stacking member 18 at one end in the stacking direction, from the flow path 16A to the flow path 17A. It merges with the third flow path F3 that communicates. The third flow path F3 is a flow path for supplying water for diluting the fuel and communicates with a flow path 18A formed in the fuel supply sheet stacking member 18 at one end in the stacking direction. .

  With this third flow path F3, the fuel introduced from the flow path 14A of the first flow path F1 can be diluted in the fuel supply sheet portion 5 and supplied to the fuel electrode 1. High concentration fuel can be supplied. Therefore, according to the fuel cell of this embodiment, the fuel can be stored in a high concentration state without putting the fuel diluted to the optimum concentration from the beginning into a fuel tank (not shown). That is, according to this embodiment, when the fuel cell is operated with the same tank capacity, the fuel cell is operated for a longer time than when the fuel diluted to the optimum concentration from the beginning is stored in the fuel tank and used. Can do.

  Next, in FIG. 7B, the fuel mixed with water introduced from the third flow path F3 in the fuel supply sheet portion 5 by introducing 100% methanol from the first flow path F1 into the fuel cell of this embodiment. Shows the output result of the fuel cell when power is supplied to the fuel electrode 1 to generate power. The output result of FIG. 7B is obtained by recording the output of a single cell 4 having a side of 23 mm as in the case of obtaining the output result of FIG. 7A. The material of the single cell 4 and the fuel supply sheet stacking members 13 to 18 of the fuel supply sheet portion 5 are under the same conditions as when the output result of FIG. 7A was obtained. The water to be diluted is introduced into the channel 16A without using a pump or other liquid feeding means due to the absorption power and capillary action of the porous PTFE, and mixed with methanol introduced from the first channel F1 in the channel 17A. Then, the unit cell 4 is supplied to the fuel electrode 1 and can be operated for power generation. Moreover, the output equivalent to the output result of FIG. 7A in which the diluted fuel is introduced from the beginning is obtained, and it can be confirmed that the fuel cell can be operated for a long time using a high concentration fuel. It was.

  More preferably, the third flow path F3 is connected to the third flow path F3 of the adjacent another single cell 4 that shares or connects the fuel supply sheet portion 5. And the flow path for supplying the water for dilution to each single cell 4 by supplying the water collect | recovered from each single cell 4 to each single cell 4 as the water for dilution from the 3rd flow path F3. Even if it does not form separately, the flow path for supplying the water for dilution in the fuel supply sheet | seat part 5 can be arrange | positioned. Furthermore, even if there is a variation in the amount of water that can be recovered from each single cell 4, the third flow path F3 is connected between each single cell 4, so that the entire plurality of single cells 4 that have been arranged are recovered. Water can be used efficiently.

  More preferably, the second flow path F2 communicates with the outside of the fuel supply sheet portion 5, and the single cells 4 are arranged two-dimensionally or three-dimensionally. The second flow path F2 that is three-dimensionally connected to discharge exhaust gas from the fuel electrode 1 is formed. As a result, the shortest amount of exhaust gas such as carbon dioxide discharged from the fuel electrode 1 of each single cell 4 arranged two-dimensionally or three-dimensionally from the second flow path F2 around the single cell 4 communicates. It can discharge | emit out of the area | region of each single cell 4 arrange | positioned by the path | route two-dimensionally or three-dimensionally. Therefore, the carbon dioxide is prevented from staying in the vicinity of the single cell 4, and the pressure of the exhaust gas in the flow path 17C of the second flow path F2 in the fuel supply sheet portion 5 of each single cell 4 is increased. It is possible to prevent the output of each single cell 4 from decreasing.

  Next, the laminated structure of the oxidant supply sheet portion 6 of the fuel cell according to this embodiment will be described. The oxidizing agent supply sheet 6 shown in FIG. 1B is formed by laminating the oxidizing agent supply sheet laminate members 20, 21, 22, and 24 shown in FIGS. 3A to 3D.

  As shown in FIG. 3A, the oxidant supply sheet laminate member 20 includes a through flow path 20A formed of a porous material, and a fluid non-permeable portion 20B that partitions the through flow path 20A. As shown in FIG. 3B, the oxidant supply sheet laminate member 21 has a through flow path 21A formed of a porous material, a fluid non-permeable portion 21B, and a flow path 23 formed of a groove. As shown in FIG. 3C, the oxidant supply sheet laminate member 22 includes a through channel 22A formed by a groove and a fluid non-permeable portion 22B that partitions the through channel 22A. As shown in FIG. 3D, the oxidant supply sheet laminate member 24 includes a through channel 24A formed by grooves and a fluid non-permeating portion 24B that partitions the through channel 24A.

  The porous material is a porous material through which the oxidant and the effluent from the oxidant electrode 3 can pass. On the other hand, the fluid non-permeating portions 20B, 22B, and 24B cannot transmit the oxidant and the effluent from the oxidant electrode 3.

  A flow path including grooves communicating from the through flow path 24A to the through flow path 22A, the flow path 23, and the flow path 20A constitutes a fourth flow path F4 for supplying the oxidant to the oxidant electrode 3. ing. Further, the through flow path 21A formed of the porous material of the oxidant supply sheet laminated member 21 constitutes a fifth flow path F5 for discharging the discharge (water) generated at the oxidant electrode 3. ing.

  The communication flow path forming the fourth flow path F4 of the oxidant supply sheet unit 5 includes a flow path 20A formed in the oxidant supply sheet lamination member 20 at one end in the stacking direction, and oxidation at one end in the stacking direction. The agent supply sheet laminate member 20 is disposed so as to face the oxidant electrode 3.

Thereby, in the oxidant supply sheet portion 6, the oxidant (air in this embodiment) introduced into the through flow path 24A opened by the fourth flow path F4 formed of the communication flow path formed by the groove is Furthermore, it is introduced into the flow path 20A through the flow path 22A and the flow path 23 that communicate with each other. Then, oxygen in the air diffused into the flow path 20A reacts with cations (H ⁺ ) and electrons from the fuel electrode 1 at the oxidant electrode 3 to generate water vapor. Since the flow paths 24A, 22A, 23, and 20A forming the fourth flow path F4 form a three-dimensional flow path as a communication flow path, the flow path 24A, 22A, 23, and 20A is on the single cell 4 as compared with the planar flow path layout. Each region can efficiently supply the oxidant through the shortest optimum route.

  In this embodiment, as the oxidant supply sheet laminate members 20, 21, 22, and 24 constituting the oxidant supply sheet unit 6, for example, porous silicon, carbon paper, a sintered body of carbon, sintering of nickel, etc. A porous material having chemical resistance such as metal, porous polyimide resin, and porous PTFE (polytetrafluoroethylene) can be used. In addition, the porous structure of the flow paths 20A and 21A made of the porous material of each of the sheet laminated members 20, 21, 22, and 24 may be a structure that induces capillary flow of fluid, and may be a fiber structure. . In order to easily induce capillary flow, these porous materials may be hydrophilized.

  In a typical example in this embodiment, the thickness of the oxidant supply sheet laminate members 20 and 21 is about 30 μm to 200 μm, and the pore diameter of the porous material is about 0.01 μm to 10 μm. Is about 100 μm to 2000 μm in the flow path 21A, for example.

  In the present invention, the pore size of the porous material that is the passage region and the width of each flow path are relatively determined by the size of the single cell, the diffusion rate in the oxidant supply sheet laminate member, etc. The size is not limited to the above dimensions. Further, the present invention is not limited to the number and layout of the flow paths to the embodiments shown in FIGS. 1A, 1B, 2A to 2F, and 3A to 3D. Needless to say.

  More preferably, the oxidant supply sheet laminate members 20, 21, 22, and 24 are adjacent to the flow paths 20A, 21A, 23, 22A, and 24A, and are fluids that cannot transmit oxidant and effluent from the oxidant electrode. In the non-permeable portions 20B, 21B, 22B, and 24B, a fluid non-permeable portion is formed by filling the same structural portion as the porous material serving as the flow path with a filler. Thereby, in each oxidizing agent supply sheet member 20, 21, 22, 24, the flow paths 20A, 21A, 23, 22A, 24A can be defined by the fluid non-permeable portions 20B, 21B, 22B, 24B. Thereby, the porous through channels 20A and 21A can be easily formed simply by introducing the filler into the sheet-like porous material. As the filler, a resin such as PTFE (polytetrafluoroethylene), acrylic, or polyimide can be used.

  In this embodiment, the oxidant supply sheet section 6 has an oxidant supply sheet laminated member at one end in the stacking direction from the flow path 24A through the flow paths 22A and 23 as a communication flow path for supplying the oxidant. And a fifth flow path F5 composed of a fourth flow path F4 that reaches the flow path 20A formed in 20 and a flow path 21A for discharging water generated in the oxidizer electrode 3 from the flow path 20A. Further, the fourth flow path F4 and the fifth flow path F5 are separated.

  Thereby, not only can the water as the reaction product of the oxidant electrode 3 be efficiently discharged from the fifth flow path F5, but also the water stays in the flow path 20A and the oxidant from the fourth flow path F4 is removed. Inhibition of the flow can be suppressed, the supply efficiency of the oxidant to the oxidant electrode 3 can be increased, and the output density of the single cell 4 can be increased.

  In this embodiment, the fuel supply sheet laminating member 13 and the oxidant supply sheet laminating member 24 do not have a porous material through-flow passage, and only the flow passage 13A and the flow passage 24A formed by grooves are formed. It has not been. Therefore, the laminated members 13 and 24 are not necessarily made of a porous material, and may be ordinary resin sheets. Thereby, for example, as shown in FIG. 1B, the mechanical strength of the entire fuel cell can be ensured by using a thick dense member that is not porous for the oxidant supply sheet laminate member 24.

  Next, in FIG. 7C, in the fuel cell of this embodiment, the air is taken in from the fourth flow path F4, and the power generation operation is performed while collecting the water generated in the oxidizer electrode 3 from the fifth flow path F5. The output result of the fuel cell is shown. The output result of FIG. 7C is obtained by recording the output of the single cell 4 having a side of 23 mm, similarly to the case of obtaining the output results of FIGS. 7A and 7B. The material of the single cell 4 is the same as that obtained when the output results of FIGS. 7A and 7B are obtained. Further, hydrophilic porous PTFE (polytetrafluoroethylene: manufactured by Sumitomo Electric Fine Polymer Co., Ltd.) was used for the oxidant supply sheet laminated member of the oxidant supply sheet portion 6. The hydrophilic porous PTFE has an average pore size of 0.45 μm. Further, acrylic resin is used as a filler for the fluid non-permeable portions 20B, 21B, 22B, and 24B of the oxidant supply sheet laminated members 20, 21, 22, and 24.

  The water produced at the oxidant electrode 3 is recovered without using a pumping means such as a pump due to the absorption capacity and capillary action of the porous PTFE, and the air supply to the oxidant electrode 3 is also carried out like a pump. A single cell could be operated for power generation without using any means. Therefore, even if the fuel cell of this embodiment is not supplied by a pump or the like, the water generated in the oxidant electrode 3 can be efficiently recovered and high output can be obtained even if the size is reduced.

  More preferably, the fourth flow path F4 communicates with the outside of the oxidant supply sheet portion 6, and the plurality of single cells 4 are arranged two-dimensionally or three-dimensionally, whereby the single cell The fourth flow path F4 that is three-dimensionally connected to supply the oxidizing agent to the four oxidizing agent electrodes 3 is formed. As a result, the single cell is passed from the outside of the region of each single cell 4 arranged two-dimensionally or three-dimensionally through the fourth flow path F4 three-dimensionally connected around each single cell. Ventilation through the outside of the area 4 can be secured by a plurality of routes. Therefore, it is possible to prevent air from staying around the single cell 4 and decrease the supply of oxygen to each single cell, and to prevent a decrease in output of each single cell.

  More preferably, as shown in FIGS. 3B and 2D, the flow path 21 </ b> A of the fifth flow path F <b> 5 is formed by joining the fuel supply sheet portion 5 and the oxidant supply sheet portion 6 around the single cell 4. The part 26 communicates with the flow path 16A of the third flow path F3. Thereby, the water produced | generated by the oxidizing agent electrode 3 can be collect | recovered through the 5th flow path F5, can be supplied to the fuel electrode 1 side through the 3rd flow path F3, and can be utilized for dilution of a fuel.

  More preferably, the fifth flow path F5 is connected to the fifth flow path F5 of the adjacent single cells 4 that share or connect the oxidant supply sheet portion 6. As a result, the water collected through the fifth flow path F5 of each single cell 4 can be shared with the adjacent single cell 4 as dilution water, and the amount of water that can be recovered from each single cell 4 varies. Even if it exists, the efficiency supply according to the usage-amount of the water by the fuel electrode 1 side of each single cell 4 is attained.

(Second embodiment)
In the above description, each single cell 4 of the fuel cell has been described centering on the example shown in FIGS. 1A to 3D in which the fuel electrode 1 and the oxidant electrode 2 are arranged in the same direction. It is not necessary that the pole 1 and the oxidant electrode 2 are arranged in the same direction. That is, as in the second embodiment shown in the cross-sectional views of FIGS. 8A to 8D, in the single cells 4, 4, 4, 4 adjacent in the stacking direction, the fuel electrode 1 and the fuel electrode 1 face each other, and the oxidant electrode The single cells 4 may be three-dimensionally arranged so that the electrode 3 and the oxidant electrode 3 face each other. In the second embodiment, as shown in FIGS. 8A to 8D, a plurality of unit cells 4 adjacent in the stacking direction can share a part of the fuel supply sheet portion 5 or the oxidant supply sheet portion 6. 8B shows a BB ′ section in FIG. 8A, FIG. 8C shows a CC ′ section in FIG. 8A, and FIG. 8D shows a DD ′ section in FIG. 8A.

  Hereinafter, the second embodiment will be described with reference to FIGS. 8A to 8D. In the second embodiment, the basic configuration and operation of the unit cell 4, the fuel supply sheet unit 5, and the oxidant supply sheet unit 6 are the same as those in the first embodiment. On the other hand, in the second embodiment, two unit cells 4 adjacent in the stacking direction use the fuel supply sheet stacking member 14 or the oxidant supply sheet stacking member 24, and the fuel supply sheet stacking member 13 is unnecessary. become. Therefore, according to this 2nd Embodiment, the usage-amount of a laminated member can be reduced.

  In the second embodiment, as in the example shown in FIG. 8A, the single cell 4 that is in communication with the adjacent single cell 4 and that is adjacent to the stacking direction in the flow path 14A to which the high concentration fuel is supplied at a sufficient supply pressure. Share on. Thereby, the total extension of the flow path 14A in the entire fuel cell can be shortened, and the fuel can be used for power generation more efficiently. Also, as shown in FIG. 8B, the pressure drop in the flow path 14A is reduced by joining the fuel supply sheet 5 and the oxidant supply sheet 6 so that the flow path 14A is not bent near the joint 25. In addition, the flow path 14A can be easily filled with fuel, the space 9 around the joint portion 25 can be further secured, and ventilation (ventilation) for supplying the oxidant can be easily secured. In the first embodiment shown in FIG. 1B, the fuel supply sheet 5 and the oxidant supply sheet 6 can be joined so as not to bend the flow path 14A. When 4 is laminated in the same direction, the flow path 14A cannot be used, so the space 9 around the joint becomes smaller than the configuration shown in FIG. 5A.

  Further, in the second embodiment, as shown in FIG. 8C, the flow path 16A constituting the third flow path F3 is communicated between the single cells 4 and 4 adjacent to each other in the plane direction orthogonal to the stacking direction. . Further, the flow path 21A constituting the fifth flow path F5 communicates between the single cells 4 and 4 adjacent in the planar direction. Therefore, water for fuel dilution can be supplied from the third flow path F3 communicating between the plurality of single cells 4 to the first flow path F1 of each single cell 4. Further, for example, when water collected from the fifth flow path F5 (flow path for discharging water generated by the oxidizer electrode 3) of each unit cell 4 is passed through the third flow path F3. Even if there is a variation in the amount of water collected from each single cell 4, the third flow path F3 communicates with each single cell 4, so that the collected water can be efficiently collected throughout the plurality of single cells. Can be used. Further, since the fifth flow path F5 communicates with each single cell, the fifth flow path can be obtained even if the amount of discharge (water) in the oxidant electrode 3 of each single cell 4 varies. The amount of water that can be recovered to F5 can be stabilized. Therefore, water for fuel dilution can be stably supplied from the fifth flow path F5 to the third flow path F3.

  Further, in the second embodiment, as shown in FIG. 8D, the second flow path F2 communicates between the single cells 4 and 4 adjacent in the stacking direction and between the single cells 4 and 4 adjacent in the plane direction. Yes. Therefore, the exhaust gas such as carbon dioxide discharged from the fuel electrode 1 of each single cell 4 arranged two-dimensionally or three-dimensionally from the second flow path F <b> 2 connected around the plurality of single cells 4. It can discharge | emit out of the area | region of each single cell 4 arrange | positioned in the said two-dimensional or three-dimensional by the shortest path | route. This can prevent a decrease in the output of each single cell 4.

  Further, in the second embodiment, as shown in FIG. 8D, the flow that forms the fourth flow path F4 between the single cells 4 and 4 adjacent in the stacking direction and between the single cells 4 and 4 adjacent in the planar direction. The path 23 communicates. Therefore, the oxidant (air) is transferred to the oxidant electrode 3 of each single cell 4 from the fourth flow path F4 communicating around the plurality of single cells 4 arranged two-dimensionally or three-dimensionally through the shortest path. Can supply. In addition, from the outside of the region of each single cell 4 arranged two-dimensionally or three-dimensionally, it passes through the fourth flow path F4 three-dimensionally connected around each single cell 4, and the single unit Ventilation through the outside of the cell 4 area can be secured by a plurality of paths. For this reason, it can prevent that an oxidizing agent (air) stagnates around the single cell 4, and the supply of oxygen to each single cell 4 falls, and the output reduction of each single cell 4 can be prevented.

(Third embodiment)
In the first and second embodiments described above, the two-dimensionally arranged single cells 4 are separated from each other, but the single cells 4 do not necessarily have to be separated. That is, as in the third embodiment shown in FIGS. 9A to 9F, a structure in which a plurality of two-dimensionally arranged single cells 44 are combined and integrated may be used. Alternatively, the single cells 44 may be arranged three-dimensionally by stacking a plurality of single cells 44 in an integrated structure.

  FIG. 9A is a plan view of the fuel cell according to the third embodiment as viewed from above the oxidant supply sheet laminate member 24, FIG. 9B is a cross-sectional view showing a cross section EE ′ of FIG. 9A, and FIG. 9A is a cross-sectional view showing the FF ′ cross section of FIG. 9A, FIG. 9D is a cross-sectional view showing the GG ′ cross section of FIG. 9A, and FIG. 9E is a cross-sectional view showing the HH ′ cross section of FIG. . FIG. 9F is a plan view showing a structure in which a plurality of single cells 44 arranged two-dimensionally are combined and integrated.

  A range surrounded by a one-dot chain line in FIGS. 9A and 9F is one power generation unit 70 in a single-cell repetitive structure. In the third embodiment, the basic configuration and operation are the same as those in the first and second embodiments described above. On the other hand, in the third embodiment, as shown in FIG. 9F, the electrolyte membrane 42, the fuel electrode 41, and the oxidant electrode 43 included in the single cell 44 that forms one power generation unit have a shape in which four corners of a square are cut. There is a difference from the electrolyte membrane 2, fuel electrode 1, and oxidant electrode 3 of the first and second embodiments described above. In the third embodiment, the basic configuration and operation are the same as those of the fuel supply sheet unit 5 and the oxidant supply sheet unit 6 in the first and second embodiments except for the shape corresponding to the single cell 44. A fuel supply sheet part and an oxidant supply sheet part are provided. Therefore, in the third embodiment, the fuel supply sheet portion, the oxidant supply sheet portion, each fuel supply sheet lamination member, and the oxidant supply sheet lamination member will be described using the same reference numerals as those in the first and second embodiments. To do.

  In the third embodiment, the fuel electrode 41, the electrolyte membrane 42, and the oxidizer electrode 43 of the plurality of single cells 44 that are two-dimensionally arranged are continuously planar cells between the adjacent single cells 44. Is configured. Adjacent single cells 44 arranged two-dimensionally are continuous on one side of the quadrangular shape with the four corners cut off, and fuel is supplied on the adjacent side (side surface 44A of the single cell 44). The sheet part 5 and the oxidant supply sheet part 6 are joined to form a joined part.

  As shown in FIG. 9F, the space 88 around the joint portion can be secured at locations corresponding to the four corners of the square, and is more square than the space 8 around the connecting portion 7 of the first embodiment shown in FIG. 1A. Or it is a cross-sectional shape close | similar to a circle | round | yen, and reduction of the flow path loss of the gas which passes can be aimed at. Further, since the continuous portions X of the plurality of single cells 44 are continuously integrated with the adjacent single cells, the mounting density can be increased while ensuring the electrode area of the single cells 44 to the maximum.

  Furthermore, in the third embodiment, since the single cells 44 arranged two-dimensionally are not separated, the single cells arranged two-dimensionally in the manufacturing stage can be stacked together. Accordingly, the manufacturing process can be simplified as compared with the case where the individually separated single cells are arranged two-dimensionally or three-dimensionally. In this embodiment, since the plurality of single cells 44 arranged two-dimensionally are integrated, wiring for connecting the fuel electrode and the oxidant electrode of adjacent single cells to each other is not necessary.

  In the third embodiment, all the two-dimensionally arranged single cells 44 are connected in parallel, and the two-dimensionally arranged single cells cannot be connected in series as shown in FIG. Since it becomes unnecessary, the manufacturing process can be simplified.

(Fourth embodiment)
Next, based on FIG. 10A-FIG. 10C, the manufacturing method of the fuel supply sheet | seat part with which the fuel cell of this invention is provided is demonstrated. FIG. 10A to FIG. 10C are process cross-sectional views schematically showing, in order, steps for producing a fuel supply sheet laminated member constituting the fuel supply sheet portion.

  In this method of manufacturing a fuel supply sheet laminated member, first, as shown in FIG. 10A, a transfer substrate 82 is disposed on a sheet-like member 84 having a porous structure formed of a porous material. The transfer substrate 82 has convex portions 82A, 82B, and 82C, and material layers 83A, 83B, and 83C containing a filler are laminated on the convex portions 82A, 82B, and 82C. The protrusions 82A, 82B, and 82C are patterned so that the material layer 83 can be transferred to a region where the filler is to be filled in the porous sheet-like member 84.

  Next, as shown in FIG. 10B, the convex portion 82A on which the material layer 83 of the transfer substrate 82 is laminated is overlapped with the region of the sheet-like member 84 which is the fluid non-permeable portion 85A, 85B, 85C. Press. As a result, the material including the filler of the material layer 83 is transferred to the sheet-like member 84, and the filler is filled in the areas to be the fluid non-permeable portions 85A, 85B, 85C as shown in FIG. 10C. Thus, the fluid impermeable portions 85A, 85B, 85C are formed. Further, porous flow paths 86 and 87 are formed which are adjacent to the fluid non-permeable portions 85A, 85B and 85C and through which the fluid can pass.

  According to the manufacturing method of this embodiment, the porous sheet-like member 84 is filled with the filler to form the porous flow paths 86 and 87 and the fluid non-permeable portions 85A, 85B, and 85C. . Therefore, in the manufacturing method of this embodiment, unlike the case where the porous structure flow path is formed by packing the porous material in the flow path groove formed on the substrate, the porous structure flow paths 86 and 87 and the flow path are formed. There is no gap between the fluid non-permeable portions 85A, 85B, and 85C that define the path. Therefore, the fluid does not permeate more than the permeability coefficient of the porous material through the gap at the interface between the channels 86 and 87 made of the porous material and the channel wall, and the fluid has the permeability coefficient of the porous material. Can be controlled stably.

  As described above, porous silicon, carbon paper, sintered carbon, sintered metal such as nickel, porous polyimide resin, and porous PTFE are used as the porous material constituting the sheet-like member 84. Is possible. Here, an example of conditions when using porous PTFE having an average pore diameter of 0.05 μm and a thickness of about 30 μm as the porous material will be described. As the material layers 83A to 83C containing the filler, an acrylic resin dissolved in a solvent so as to be easily applied was used. Moreover, the film thickness of the material layers 83A to 83C containing the filler was set to about 50 μm. Since the film thickness of the material layers 83A to 83C containing the filler is set according to the film thickness of the sheet-like member 84, it is not limited to the above value, but from one time the film thickness of the sheet-like member 84. It should be about 3 times. If the film thickness of the material layers 83A to 83C containing the filler is too small, the filler cannot be sufficiently filled in the sheet-like member 84 having a porous structure. On the other hand, if the film thickness of the material layers 83A to 83C is too large, the fluid non-permeable portions (filled regions) 85A to 85C spread too much in the direction along the plane perpendicular to the thickness direction, The flow paths 86 and 87, which are fluid permeable regions, are too narrow.

  In this embodiment, as shown in FIG. 10B, the transfer substrate 82 is superposed on the porous sheet-like member 84, and the material layers 83 </ b> A to 83 </ b> C containing the filler are transferred from the transfer substrate 82 to the porous structure. It is preferable to impregnate the porous structure into the porous structure by annealing in the process of transferring the filler to the regions to be the fluid impermeable portions 85A to 85C. By performing this annealing, the filler is removed from the fluid of the sheet-like member 84 as compared with the case where the material layers 83A to 83C including the filler are transferred to the regions that are the fluid non-permeable portions 85A to 85C by pressing alone. It can be sufficiently distributed in the porous structure as the transmission parts 85A to 85C. Therefore, fuel leakage from the porous flow paths 86 and 87 can be reliably suppressed.

  As for the annealing conditions, for example, if annealing is performed at a temperature of about 80 to 120 ° C. for about 10 to 60 minutes, the PTFE porous structure can be sufficiently impregnated with the filler. The annealing temperature and annealing time depend on the film thickness and average pore diameter of the sheet-like member 84, the viscosity of the filler, and the like, but are not limited to this. Under the conditions of this embodiment, the annealing temperature is If the temperature is less than 80 ° C., the solvent used for applying the material containing the filler does not volatilize sufficiently, and the filler may not be firmly fixed in the sheet-like member 84.

  Moreover, when the annealing temperature exceeds 120 ° C., the material containing the filler in the sheet-like member 84 diffuses rapidly, and there is a possibility that it is difficult to apply to a fine flow path pattern. In order to suppress the diffusion of the filler and securely fix the filler in the sheet-like member 84, the temperature is gradually increased over a period of about 30 minutes, and then annealed at a temperature of 100 ° C. or more for about 10 minutes. Good.

  Next, a fuel of a substantially monolithic laminated structure having at least one communication channel by aligning and laminating a plurality of fuel supply sheet laminated members produced in the same process as in FIGS. 10A to 10C. A supply sheet portion can be formed. Note that annealing is preferably performed after the above alignment and lamination. By performing this annealing, the filler in each fuel supply sheet laminate member is also impregnated in the interface between each fuel supply sheet laminate member. Thereby, the filler-impregnated region can be formed at the interface. Thereby, while each fuel supply sheet lamination | stacking member is joined, it can suppress that a fuel leaks along the interface between each fuel supply sheet | seat lamination member.

  Next, an example of a method for manufacturing the transfer substrate 82 will be described. First, a substrate on which a material layer containing a filler is formed is prepared separately, and a transfer substrate 82 having convex portions 82A to 82C is disposed so as to face the material layer of the substrate. Next, the convex portions 82A to 82C of the transfer substrate 82 are pressed against a material layer containing a filler formed on the surface of the substrate. Thereby, the material layers 83A to 83C containing the filler can be laminated on the convex portions 82A to 82C of the transfer substrate 82.

  Note that the substrate on which the material layer including the filler is formed is not particularly limited, but it is preferable to use a flexible and highly flat substrate. Here, a PET (polyethylene terephthalate) sheet was used. Since PET is flexible, it can be easily peeled off from the transfer substrate 82. Moreover, since PET has high flatness, the material layers 83A to 83C including the filler are easily peeled off from the substrate of the PET sheet. Thereby, the film thickness of the material layers 83A to 83C including the filler transferred to the transfer substrate 82 can be sufficiently ensured.

  Moreover, it can be understood that the oxidant supply sheet laminated member of the oxidant supply sheet portion can also be produced by the same manufacturing method as the fuel supply sheet laminated member produced by the embodiment shown in FIGS. 10A to 10C.

  More preferably, when joining the fuel supply sheet portion and the oxidant supply sheet portion, the fuel supply sheet lamination member and the oxidant supply sheet lamination member are aligned and laminated before annealing is performed. . By performing this annealing, the filler impregnated in the fluid non-permeable portion of the fuel supply sheet laminated member or the fluid non-permeable portion of the oxidant supply sheet laminated member is also impregnated in the interface between the two sheet laminated members. Thereby, the filler-impregnated region can be formed at the interface. Accordingly, both the sheet members are joined to each other, and the fuel and the like can be prevented from leaking along the interface between the both sheet members.

  More preferably, when the fuel supply sheet portion and the oxidant supply sheet portion are joined around the single cell, annealing is performed after alignment and lamination. By performing this annealing, the fuel supply sheet laminated member or the oxidant supply adjacent to the side surface of the single cell is filled with the filler impregnated in the fluid non-permeable portion of the fuel supply sheet laminated member or the oxidant supply sheet laminated member. It is also impregnated at the interface between the sheet portions. Thereby, while the side surface of the said single cell, the said fuel supply sheet | seat part, and the said oxidizing agent supply sheet | seat part can be bonded together, it can suppress that a fuel etc. leak along the interface between a single cell side surface and a sheet | seat member.

  As mentioned above, although embodiment of this invention was described, it should be thought that the said disclosed embodiment is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 Fuel electrode 2 Electrolyte membrane 3 Oxidant electrode 4, 44 Single cell 5 Fuel supply sheet | seat part 6 Oxidant supply sheet | seat part 7 Connection part 8 Space around a connection part 9 Space 10, 10B, 10C Connection part 11A, 11B, 11C Adjacent Wirings 12A, 12B for connecting the single cells to be connected Wirings 13-18, 50, 84 for connecting the adjacent single cells 13A, 14A, 14C, 15A, 15C, 16C, 16D, fuel supply sheet laminate members 17A, 17C, 18A Flow path 13B, 14B, 15B, 16B, 17B, 18B Fluid non-permeating part 19 Communication flow path 20, 21, 22, 24 Oxidant supply sheet laminated member 20A, 21A, 23, 22A, 24A Flow path 20B, 21B, 22B, 24B Fluid impermeable portion 25 Joint portion 50A Fuel supply path 56, 70 Power generation unit 82 Transfer substrate 82A-82C Convex portion 83A-83C Including filler Material layer 84 Sheet-like members 85A, 85B, 85C having a porous structure Fluid non-permeable portions 86, 87 Flow paths having a porous structure

Claims (25)

A fuel electrode that generates cations and electrons from the supplied fuel, an electrolyte membrane that is disposed so as to face the fuel electrode and allows cations from the fuel electrode to pass therethrough, and so as to face the electrolyte membrane A plurality of unit cells each having a stack of an oxidant electrode arranged to react with the supplied oxidant and the cation disposed and permeated through the electrolyte membrane;
A fuel supply sheet portion disposed to face the fuel electrode of the single cell and having a flow path for supplying the fuel to the fuel electrode;
An oxidant supply sheet portion disposed so as to face the oxidant electrode of the single cell and having a flow path for supplying the oxidant to the oxidant electrode;
A first array part in which the plurality of single cells are continuously arrayed by a flexible connecting part that connects at least one of the fuel supply sheet part or the oxidant supply sheet part;
A plurality of adjacent single cells arranged in the stacking direction have at least one of the second arrangement part sharing at least one of the fuel supply sheet part or the oxidant supply sheet part. A fuel cell. The fuel cell according to claim 1, wherein
The fuel cell, wherein the fuel supply sheet portion and the oxidant supply sheet portion are joined around the single cell while sandwiching the single cell. The fuel cell according to claim 2, wherein
A wiring for electrically connecting to either the fuel electrode or the oxidant electrode of the single cell is disposed at a location where the fuel supply sheet unit and the oxidant supply sheet unit are joined around the single cell. A fuel cell characterized by comprising: The fuel cell according to any one of claims 1 to 3,
A first wiring that electrically connects the oxidant electrodes of the two adjacent single cells;
A second wiring for electrically connecting the fuel electrodes of the two adjacent single cells;
At least one of the fuel electrode of one unit cell of the two adjacent unit cells and the third wiring that electrically connects the oxidant electrode of the other unit cell is the first array. A fuel cell, wherein the fuel cell is disposed along the connecting portion of the portion. The fuel cell according to any one of claims 1 to 4, wherein
The fuel supply sheet is
Having a plurality of fuel supply sheet lamination members laminated in the direction of lamination,
The plurality of fuel supply sheet laminated members are
Including a flow path portion penetrating in the direction of the lamination and the flow path portion is formed of a hollow or porous material,
A flow path portion made of a porous material of the plurality of fuel supply sheet laminate members communicates to form a first flow path for supplying the fuel to the fuel electrode;
A hollow flow path portion of the plurality of fuel supply sheet laminated members or a flow path portion made of a porous material communicates to form a second flow path for discharging the discharge from the fuel electrode. A fuel cell. The fuel cell according to claim 5, wherein
The fuel supply sheet laminated member is
It has a fluid non-permeating part adjacent to the flow path part, and the fluid non-permeating part is filled with a filler and cannot pass through the fuel and the discharge from the fuel electrode. Fuel cell. The fuel cell according to claim 5 or 6,
The fuel cell according to claim 1, wherein at least a part of the first flow path is separated from the second flow path by a fluid non-permeable portion of the fuel supply sheet stacking member. The fuel cell according to claim 7, wherein
The first flow path is
A fuel cell comprising a supply suppressing structure that is disposed upstream of the fuel supply sheet stacking member at one end on the fuel electrode side in the stacking direction and suppresses the flow of the fuel. The fuel cell according to claim 8, wherein
Comprising a plurality of adjacent single cells arranged in the direction of the stack,
Furthermore, it has a fuel flow path that communicates each first flow path of each fuel supply sheet portion disposed opposite to each single cell on the upstream side of the supply suppression structure,
The fuel cell is characterized in that one end in the stacking direction is closed. The fuel cell according to any one of claims 7 to 9,
The fuel supply sheet is
A third flow path for supplying water for diluting the fuel supplied to the first flow path to the first flow path;
The third flow path is
A fuel cell characterized in that it joins the first flow path upstream of the fuel supply sheet laminated member at one end on the fuel electrode side. The fuel cell according to claim 10, wherein
3. The fuel cell according to claim 1, wherein the third flow path of the fuel supply sheet portion communicates between a plurality of single cells. The fuel cell according to any one of claims 5 to 11,
The second flow path is
A fuel cell characterized in that it communicates across a plurality of single cells of at least one of the first array part and the second array part and communicates with the outside of the fuel supply sheet part. The fuel cell according to any one of claims 1 to 12,
The oxidant supply sheet portion is
Having a plurality of oxidant supply sheet laminate members laminated in the direction of lamination,
The plurality of oxidant supply sheet laminated members are:
Including a flow path portion penetrating in the direction of the lamination and the flow path portion is formed of a hollow or porous material,
A hollow flow path portion of the plurality of oxidant supply sheet laminated members or a flow path portion made of a porous material communicates to form a fourth flow path for supplying an oxidant to the oxidant electrode. ,
A hollow flow path portion of the plurality of oxidant supply sheet laminated members or a flow path portion made of a porous material communicates to form a fifth flow path for discharging the effluent from the oxidant electrode. A fuel cell characterized by comprising: The fuel cell according to claim 13, wherein
The oxidant supply sheet laminated member is
It has a fluid non-permeation part adjacent to the flow path part, and the fluid non-permeation part is filled with a filler and cannot pass the oxidant and the effluent from the oxidant electrode. A fuel cell. The fuel cell according to claim 13 or 14,
The fuel cell, wherein the fourth flow path is at least partially separated from the fifth flow path by the fluid non-permeable portion of the oxidant supply sheet laminate member. The fuel cell according to claim 15, wherein
The fourth flow path is
A fuel cell characterized in that it communicates between a plurality of single cells of the first array section and the second array section and communicates with the outside of the oxidant supply sheet section. The fuel cell according to claim 15 or 16,
The fifth flow path communicates with the third flow path at a joint portion where the fuel supply sheet portion and the oxidant supply sheet portion around the single cell are joined. A fuel cell. The fuel cell according to any one of claims 15 to 17,
The fifth flow path is
A fuel cell characterized in that it communicates across a plurality of single cells of at least one of the first array section or the second array section. A method for manufacturing a fuel cell according to any one of claims 1 to 18, comprising:
Form a material layer containing a filler on the convex part of the transfer substrate,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is Transferred to a sheet-like member,
The region of the sheet-like member on which the convex portions are overlapped is filled with the filler so that the region becomes a fluid non-permeable portion through which the fuel and the discharge from the fuel electrode cannot permeate. Forming a flow path part that is adjacent to the part and through which the fuel and the discharge from the fuel electrode can pass,
A substantially monolithic laminated structure comprising a plurality of the sheet-like members on which the flow path part and the fluid non-permeation part are stacked, and at least one communication flow path communicating with the flow path part. A fuel cell manufacturing method comprising forming a fuel supply sheet portion of a body. The method of manufacturing a fuel cell according to claim 19,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is When transferring to a sheet-like member
A method for producing a fuel cell, wherein the porous material is impregnated with the filler by annealing. A method for manufacturing a fuel cell according to any one of claims 1 to 18, comprising:
Form a material layer containing a filler on the convex part of the transfer substrate,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is Transferred to a sheet-like member,
The region of the sheet-like member on which the convex portions are overlapped is filled with the filler, and the region becomes a fluid non-permeable portion through which the discharge from the oxidant and the oxidant electrode cannot permeate. Forming a flow path section that is adjacent to the non-permeable section and through which the oxidant and the discharge from the oxidizer electrode can pass,
A substantially monolithic laminated structure comprising a plurality of the sheet-like members on which the flow path part and the fluid non-permeation part are stacked, and at least one communication flow path communicating with the flow path part. A method of manufacturing a fuel cell, comprising forming an oxidant supply sheet portion of a body. The method of manufacturing a fuel cell according to claim 21,
The convex portion of the transfer substrate on which the material layer containing the filler is formed is superimposed on the sheet-like member formed of a porous material through which fluid can pass, and the material containing the filler is When transferring to a sheet-like member
A method for producing a fuel cell, wherein the porous material is impregnated with the filler by annealing. In the manufacturing method of the fuel cell according to any one of claims 19 to 22,
The convex part of the transfer substrate is pressed against the material layer of the material substrate on which the material layer containing the filler is formed, and the material containing the filler is transferred to the convex part, and the convex part of the transfer substrate And forming a material layer containing the filler on a fuel cell. The method for manufacturing a fuel cell according to any one of claims 19 to 23,
The fuel supply sheet portion adjacent to the filler in the fluid non-permeating portion by annealing when the fuel supply sheet portion and the oxidant supply sheet portion are joined around the single cell while sandwiching the single cell. The fuel supply sheet portion and the oxidant supply sheet portion are bonded together by impregnating the joining region between the oxidant supply sheet portion and the oxidant supply sheet portion. The method for producing a fuel cell according to claim 24,
When the single cell is sandwiched between the fuel supply sheet portion and the oxidant supply sheet portion and joined around the single cell, the filler in the fluid non-permeable portion is adjacent to the side surface of the single cell by annealing. Manufacturing the fuel cell, wherein the side surface of the single cell is bonded to the fuel supply sheet portion and the oxidant supply sheet portion by impregnation between the fuel supply sheet portion or the oxidant supply sheet portion. Method.

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