JP2011165395A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell with which flooding due to the moisture infiltrating the inside of the fuel cell can be suppressed, and continuous and stable power generation is made possible, even if the fuel cell is placed directed in any directions. <P>SOLUTION: The fuel cell is formed, by laminating a plurality of electrode-electrolyte integrated structures, each of which has a positive electrode, a negative electrode and a solid polymer electrolyte membrane, via separators 10. On a side farther outside to the surface side than the electrode-electrolyte integrated structure located at one of the utmost-end parts out of the plurality of the laminated electrode-electrolyte integrated structures, a drainage mechanism 60 is provided which has the same area as that of the separator 10 in plan view. On the surface side farther out than the electrode-electrolyte integrated structure located at the other utmost end part out of the plurality of the laminated electrode-electrolyte integrated structure, a fuel supply port 80 and a fuel exhaust port 90 are provided, and the drainage mechanism 60, the fuel supply port 80, and the fuel exhaust port 90 are connected to one another by a gas-liquid separation tube, respectively. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel cell that can suppress flooding due to moisture contained in hydrogen as a fuel and can stably generate power continuously.

  In recent years, with the spread of cordless devices such as personal computers and mobile phones, there has been a demand for further downsizing and higher capacity of batteries as power sources. Currently, lithium ion secondary batteries have been put into practical use as secondary batteries that have high energy density and can be reduced in size and weight, and demand for portable power sources is increasing. However, this lithium ion secondary battery has a problem that it cannot guarantee a sufficient continuous use time for some cordless devices.

  In order to solve such problems, development of fuel cells such as a polymer electrolyte fuel cell (PEFC) has been underway. The fuel cell can be used continuously if fuel and oxygen are supplied. An electrode / electrolyte integrated product (hereinafter sometimes referred to as “MEA: Membrane Electron Assembly”) comprising a positive electrode, a negative electrode, and a solid polymer electrolyte as an electrolyte is provided, and the positive electrode active material has oxygen in the air. The PEFC using hydrogen as a negative electrode active material has attracted attention as a battery having a higher energy density than a lithium ion secondary battery.

  In general PEFC, a plurality of MEAs are stacked, and each MEA has two types, a positive electrode side separator that forms an oxygen flow path (oxidant flow path) and a negative electrode side separator that forms a fuel flow path. Are stacked in a state of being sandwiched between the separators. Then, gas (oxygen and hydrogen as fuel) is supplied to each of the oxygen flow path and the fuel flow path of the PEFC, and electricity is generated by causing an electrochemical reaction.

  However, in PEFC, the fuel is usually supplied in a humidified state, but moisture in the fuel is condensed inside the cell, and flooding occurs where the surface of the electrode is blocked by the intrusion water thus generated, resulting in rapid output. There was a risk of lowering. For this reason, it is required to suppress the clogging of the electrode surface caused by the intrusion water.

  In order to meet such demands, attempts have been made to discharge water that has entered the fuel cell. For example, a drainage groove is formed in the separator between the MEAs, a drainage part is provided outside the MEA, Various proposals have been made such as providing a dehumidifying mechanism having a complicated configuration (see Patent Documents 1 to 7).

JP 2002-343382 A JP 2004-327058 A JP 2006-19116 A JP 2006-351323 A Japanese Patent No. 3753013 JP 2004-327059 A Japanese Patent No. 3519987

  It is possible to discharge water that has entered the fuel cell by the conventional method. However, the above conventional method is a water discharge method that assumes operation in a state where the fuel cell is placed in a specified vertical direction, and the water discharge effect when the fuel cell is placed in a direction other than the specified direction is considered. It has not been. For this reason, for example, when the fuel cell is used in a direction opposite to the prescribed vertical direction, flooding may occur, which may cause a rapid output reduction. On the other hand, if such a flooding is to be prevented by the conventional water discharge method, the installation direction of the fuel cell is fixed, and the handling of the fuel cell may be restricted. In particular, when a fuel cell is used as a power source for a portable device, the directionality of the fuel cell is strongly demanded, and stable power generation is possible without causing a sudden decrease in output in any direction. There is a need for a fuel cell capable of.

  The present invention has been made in view of the above circumstances, and provides a fuel cell that can suppress flooding due to moisture that has entered the inside of the fuel cell and can stably generate power even when placed in any direction.

  The fuel cell of the present invention comprises a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane disposed between the positive electrode and the negative electrode. A fuel cell in which a plurality of electrode / electrolyte integrated products are stacked via a separator, and the electrode / electrolyte integrated product located at one end of the plurality of stacked electrode / electrolyte integrated products Also, the outer surface is provided with a drainage mechanism having an area equivalent to that of the separator in plan view, and the outer surface of the stacked plurality of electrode / electrolyte integrated bodies is more outer than the electrode / electrolyte integrated body located at the other end. A fuel supply port and a fuel discharge port are provided on the side, and the drainage mechanism and the fuel supply port and the fuel discharge port are respectively connected by a gas-liquid separation tube.

  ADVANTAGE OF THE INVENTION According to this invention, the flooding by the water | moisture content permeated into the inside of a fuel cell can be suppressed, and the fuel cell which can produce electric power continuously and stably even if it puts a fuel cell in all directions can be provided.

It is a perspective view showing the outline of an example of the fuel cell of this invention. It is a principal part exploded view showing an example of the fuel cell of FIG. It is principal part sectional drawing showing an example of the fuel cell of FIG. FIG. 4 is a cross-sectional view of the main part of a part different from FIG. 3 of the example of the fuel cell of FIG. 1. FIG. 4 is a cross-sectional view of an essential part of another example of the fuel cell of FIG. 1 different from FIG. 3. FIG. 6A is a schematic diagram of an example of a separator according to the fuel cell of the present invention, FIG. 6A is a plan view of the side disposed on the negative electrode diffusion layer, FIG. 6B is a cross-sectional view taken along the line II of FIG. It is a top view of the side arrange | positioned. 7A is a schematic view of an example of a laminate of a positive electrode catalyst layer, a solid polymer electrolyte membrane, and a negative electrode catalyst layer in an electrode / electrolyte integrated product according to the fuel cell of the present invention, FIG. 7A is a plan view, and FIG. It is II sectional view. 8A is a schematic view of an example of a positive electrode diffusion layer in an electrode / electrolyte integrated body according to the fuel cell of the present invention, FIG. 8A is a plan view, and FIG. 8B is a cross-sectional view taken along line III-III in FIG. 8A. FIG. 9A is a schematic view of an example of a negative electrode diffusion layer in an electrode / electrolyte integrated body according to the fuel cell of the present invention, FIG. 9A is a plan view, and FIG. 9B is a cross-sectional view taken along line IV-IV in FIG. FIG. 10A is a plan view, FIG. 10B is a cross-sectional view taken along line VV of FIG. 10A, and FIG. 10C is a cross-sectional view taken along line VI-VI of FIG. 10A. FIG. 11A is a side view of an essential part of an example of a gas-liquid separation tube, and FIG. 11B is a perspective view of an essential part of an example of a connection state between the gas-liquid separation tube and a drainage mechanism. It is a schematic diagram showing an example of the fuel cell power generation system using the fuel cell of the present invention. It is a perspective view showing the outline of an example of the integrated thing of the fuel cell of this invention, and a hydrogen consumption apparatus. It is a schematic diagram showing the other example of the fuel cell power generation system using the fuel cell of this invention. It is a schematic diagram showing the further another example of the fuel cell power generation system using the fuel cell of this invention.

  The fuel cell of the present invention comprises a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane disposed between the positive electrode and the negative electrode. A plurality of electrode / electrolyte integrated products having a plurality of layers are laminated via a separator. In addition, a drainage mechanism having a surface area equivalent to that of the separator in plan view is provided on the outer surface side of the electrode / electrolyte integrated product located at one end of the plurality of stacked electrode / electrolyte integrated products. The fuel supply port and the fuel discharge port are provided on the outer surface side of the electrode / electrolyte integrated product located at the other end of the plurality of stacked electrode / electrolyte integrated products. Further, the drainage mechanism, the fuel supply port, and the fuel discharge port are respectively connected by a gas-liquid separation tube.

  In the fuel cell of the present invention, a drainage mechanism is provided, and the drainage mechanism, the fuel supply port, and the fuel discharge port are each connected by a gas-liquid separation tube. Therefore, in the fuel gas introduced from the fuel supply port Included and intrusion water generated by condensation in the fuel cell remains in the gas-liquid separation tube. For this reason, even if the fuel cell is rotated and used in all directions, the intrusion water does not reach each MEA and can be discharged from the fuel discharge port to the outside of the fuel cell system. On the other hand, the fuel gas itself can be discharged from the gas-liquid separation tube and reach each MEA. As a result, flooding can be suppressed even when the fuel cell is placed in any direction, and continuous and stable power generation is possible.

In addition, the drainage mechanism has the same area in plan view as the separator disposed between the MEAs, and is easy to stack with the MEA stack group. Therefore, the fuel cell can be manufactured easily and easily. Since it is a structure, the increase in the cost of a fuel cell (the productivity fall accompanying it) and the unnecessary volume increase can also be suppressed.
Hereinafter, an example of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view schematically showing an example of the fuel cell of the present invention. In the fuel cell 100 shown in FIG. 1, a plurality of MEAs 20 are vertically stacked with separators 10 interposed therebetween. In addition, a drainage mechanism 60 is disposed on the outer surface side (upper side in FIG. 1) of one endmost part (uppermost part in FIG. 1) of the stacked MEA 20 group. Then, both ends of the laminated body of the MEA 20 group and the drainage mechanism 60 are sandwiched between end plates 70 and 70 and fixed with bolts and nuts. Further, a fuel supply port 80 and a fuel discharge port 90 are provided on the outer surface side (lower side in FIG. 1) of the other endmost part (lowermost part in FIG. 1) of the other MEA 20 group. . Fuel is introduced into the fuel cell from the fuel supply port 80, supplied to the negative electrode of each MEA 20, and used for power generation. Then, the fuel not consumed by each MEA 20 is discharged from the fuel discharge port 90 to the outside of the fuel cell.

  Further, the intrusion water contained in the fuel introduced into each MEA 20 is discharged from the fuel discharge port 90 to the outside of the fuel cell through a gas-liquid separation tube and a drainage mechanism 60 described later.

  FIG. 2 is an exploded view of a main part of an example of the fuel cell of FIG. 1, and FIG. 3 is a cross-sectional view of a main part of an example of the fuel cell of FIG. In the figure, 20a is a laminate in which a negative electrode catalyst layer (24 in FIG. 3), a solid polymer electrolyte membrane (23 in FIG. 3), and a positive electrode catalyst layer (22 in FIG. 3) are laminated in this order from the top. The negative electrode diffusion layer 25 is disposed on the upper side, and the positive electrode diffusion layer 21 is disposed on the lower side to constitute the MEA. Separators 10 and 10 are disposed above and below the MEA. FIG. 3 is a cross-sectional view, but for the purpose of facilitating understanding of the fuel flow path formed by the fuel supply manifold and the fuel discharge manifold of each component, the upper end of the upper separator 10 and the lower separator 10 are illustrated. The back portion is omitted except for the lower end of. Moreover, in FIG. 3, the hatching of the cross section of the gas-liquid separation tube 85 is omitted.

  The separators 10 and 10 are formed with a fuel supply manifold 11 and a fuel discharge manifold 12. The separators 10 and 10 have a quadrangular shape in plan view, and each is composed of one sheet. The fuel supply manifold 11 is formed in the vicinity of one of the four sides forming the quadrangle, and the fuel discharge manifold 12 is formed in the vicinity of the one side facing the one side.

  Moreover, the separators 10 and 10 are formed with a plurality of groove-like oxygen channels 13 on one side and the other side is flat. The oxygen flow paths 13 of the separators 10 and 10 are parallel or substantially parallel to each other so that the fuel supply manifold 11 and the fuel discharge manifold 12 are linearly connected to two sides other than the opposing two sides formed in the vicinity. Is formed.

  Further, in the positive electrode catalyst layer, the solid polymer electrolyte, and the negative electrode catalyst layer related to the laminate 20a, the fuel supply manifold is located at a position corresponding to the fuel supply manifold 11 of the separators 10 and 10, and the fuel discharge manifold 12 is located. Each fuel discharge manifold is formed.

  Further, the positive electrode diffusion layer 21 is disposed so as to cover the entire surface of the formation portion of the oxygen channel 13 in the lower separator 10. A positive electrode gas seal 30 for suppressing inflow of fuel gas is disposed outside the two sides of the positive electrode diffusion layer 21 that are parallel or substantially parallel to the oxygen flow path 13 of the separator 10. A fuel supply manifold is formed at a position corresponding to the fuel supply manifold 11 of the separators 10 and 30, and a fuel discharge manifold is formed at a position corresponding to the fuel discharge manifold 12.

  Further, the negative electrode diffusion layer 25 is in contact with the flat plate surface of the upper separator 10, and a negative electrode gas seal 40 for suppressing the outflow of fuel gas is disposed outside the outer periphery thereof. A fuel supply manifold is formed at a position corresponding to the fuel supply manifold 11 of the separators 10 and 10 of the negative electrode gas seal 40, and a fuel discharge manifold is formed at a position corresponding to the fuel discharge manifold 12.

  Further, gas-liquid separation tubes 85 and 95 are arranged inside each of the fuel supply manifolds and the fuel discharge manifold. The gas-liquid separation tube 85 connects a drainage mechanism described later and the fuel supply port 80 (FIG. 1), and the gas-liquid separation tube 95 connects the drainage mechanism and the fuel discharge port 90 (FIG. 1). is doing.

  The gas-liquid separation tube is not particularly limited as long as it is a tube that is contained in the fuel gas and does not permeate the intrusion water generated by condensation in the fuel cell and permeates only the fuel gas. A ceramic porous tube such as an ethylene porous tube, a polypropylene porous tube, or a porous alumina tube subjected to water repellent treatment can be used.

  2 and 3, the flow of air containing oxygen is indicated by a dotted arrow, and the flow of fuel gas is indicated by a solid arrow. The fuel discharged from the gas-liquid separation tube 85 and introduced from the fuel supply manifold 11 is supplied to the negative electrode catalyst layer 24 through the negative electrode diffusion layer 25. Then, the fuel that is not consumed without being involved in the power generation reaction is discharged to the outside through the negative electrode diffusion layer 25 from the fuel discharge manifold.

  Further, the oxygen flow path 13 included in the separators 10 and 10 is formed so as to linearly connect two opposing sides of the quadrangular separator in a plan view, and both ends thereof are open on the side surface of the separator. Yes. Therefore, for example, air is introduced into the oxygen channel 13 by sending air containing oxygen from the side surface of the fuel cell (the side surface of the separator 10 where the oxygen channel 13 is open) using a fan or the like. The The air (oxygen) introduced into the oxygen flow path 13 is supplied to the positive electrode catalyst layer 22 through the positive electrode diffusion layer 21 of MEA. In addition, oxygen that is not involved in the power generation reaction and that is not consumed and components other than oxygen in the air are open ends of the oxygen flow path 13 on the side surface of the fuel cell (the side surface opposite to the side on which air is fed). Is discharged to the outside.

  As will be described in detail later, the negative electrode diffusion layer according to the negative electrode is generally composed of a material through which fuel can flow, such as a water-repellent porous carbon sheet. Therefore, in the fuel cell of the present invention, the fuel introduced from the fuel supply manifold is supplied to the negative electrode catalyst layer through the holes in the negative electrode diffusion layer, and the unconsumed fuel is supplied to the fuel through the holes in the negative electrode diffusion layer. It is discharged from the discharge manifold. Therefore, as shown in FIG. 2 and FIG. 3, the separator interposed between adjacent MEAs only needs to have an oxygen flow path, and there is no need to form a fuel flow path. The separator can be made thin. Therefore, it is preferable that the fuel cell of the present invention includes such a separator, whereby a more compact structure can be obtained.

In the fuel cell shown in FIGS. 2 and 3, the air passing through the oxygen flow path 13 also acts as a cooling medium. Therefore, since the oxygen flow path 13 also serves as the cooling medium flow path, there is no need to separately form a cooling medium flow path in the separator. Therefore, the separator is formed of a single layer, and the separator is made flat on one side. Even if it is thin, cooling with a cooling medium is possible.

  4 and 5 are cross-sectional views of main parts of other portions of the fuel cell of FIG. The cross-sectional view shown in FIG. 4 shows a portion including a drainage mechanism 60, a fuel supply manifold and a fuel discharge manifold, and gas-liquid separation tubes 85 and 95. 5 shows a portion including the fuel supply port 80 and the fuel discharge port 90. 4 and 5, as in FIG. 3, for the purpose of facilitating understanding of the fuel flow path formed by the fuel supply manifold and the fuel discharge manifold of each component, a part of the back portion is omitted. The hatching of the cross sections of the gas-liquid separation tubes 85 and 95 is omitted.

  In FIG. 4, the positive electrode diffusion layer 21 is disposed on the lower side of the laminate 20a, and the separator 10 is further disposed on the lower side thereof. Further, the negative electrode diffusion layer 25 is disposed on the upper side of the laminate 20a, and further on the upper side, a current collecting plate 50 for taking out the electric power generated from each MEA is disposed. A gas seal 51 is disposed outside the current collector plate. The positive electrode diffusion layer 21, the laminate 20a, and the negative electrode diffusion layer 25 constitute an MEA. This MEA corresponds to the uppermost MEA in the stacked MEA group. A drainage mechanism 60 is disposed further above the current collector plate 50 disposed above the negative electrode diffusion layer 25 of the MEA with a rubber sheet 52 for gas sealing and insulation interposed therebetween. The rubber sheet 52 is also disposed between the drainage mechanism 60 and the end plate 70.

  In FIG. 5, the positive electrode diffusion layer 21 is disposed on the lower side of the laminate 20a, and the separator 10 is disposed on the lower side thereof. Further, the negative electrode diffusion layer 25 is disposed on the upper side of the laminate 20a, and the separator 10 is also disposed on the upper side thereof. The positive electrode diffusion layer 21, the laminate 20a, and the negative electrode diffusion layer 25 constitute an MEA. This MEA corresponds to the lowest MEA in the stacked MEA group. A current collecting plate 50 and an end plate 70 for taking out the electric power generated from each MEA are disposed below the separator 10 disposed below the positive electrode diffusion layer 21 of the MEA. .

  The drainage mechanism 60 is included in the fuel introduced through the gas-liquid separation tube 85, and is a water passage layer for flowing intrusion water generated by condensation in the fuel cell to the fuel supply port 90 through the gas-liquid separation tube 95. 60a, and a gas seal 60b for suppressing gas in and out on the outer periphery of the water passage layer 60a. A fuel supply manifold is formed at a position corresponding to the fuel supply manifold 11 of the separator 10 of the gas seal 60 b, and a fuel discharge manifold is formed at a position corresponding to the fuel discharge manifold 12. In addition, gas-liquid separation tubes 85 and 95 are connected to the end of the water passage layer 60a.

  4 and 5, the flow of the fuel gas is indicated by a solid arrow, but the intrusion water generated by dew condensation in the gas-liquid separation tube 85 is a water passage layer of the drainage mechanism 60 along with the flow of the fuel gas. It passes through 60a, reaches the gas-liquid separation tube 95, and is discharged from the fuel discharge port 90 to the outside. At this time, the fuel that has passed through the fuel discharge passage formed by the separator and the fuel discharge manifold of the MEA without being involved in the power generation reaction is also discharged from the fuel discharge port 90 to the outside. As described above, in the fuel cell of the present invention, the water that has entered with the fuel gas can be efficiently discharged out of the fuel cell, so that flooding due to the intruding water can be effectively suppressed.

  The water passage layer 60a of the drainage mechanism 60 preferably has the same structure as the negative electrode diffusion layer related to the negative electrode. Specifically, like the negative electrode diffusion layer, a water-repellent porous carbon sheet or the like, It is preferable that the inside is comprised with the material which can distribute | circulate a fuel and water. By providing the water passage layer having such a structure, it is not necessary to separately form a water passage groove or the like, and a drainage mechanism having a simple configuration can be obtained.

  FIGS. 2 to 5 show examples of fuel cells having MEAs laminated in this order from the top to the negative electrode, the solid polymer electrolyte membrane, and the positive electrode. In the fuel cell of the present invention, the positive electrode, the solid You may have MEA of the structure laminated | stacked in order of the polymer electrolyte membrane and the negative electrode.

  The drainage mechanism may be arranged above the uppermost MEA in the stacked MEA group, that is, above the MEA farthest from the fuel supply port and the fuel discharge port. Since it is usual to arrange current collector plates on the upper and lower surfaces of the MEA group, the current collector plate (further, for the purpose of gas sealing and insulation) between the drainage mechanism and the uppermost MEA. Or a rubber sheet or the like) may be interposed. Further, for example, as shown in FIG. 4, in the case of a fuel cell having an MEA in which a negative electrode, a solid polymer electrolyte membrane, and a positive electrode are stacked in this order, oxygen is satisfactorily supplied to the positive electrode of the uppermost MEA. Therefore, it is preferable to arrange a separator provided with an oxygen flow path under the uppermost MEA. Therefore, in this case, as shown in FIG. 4, a current collector (or rubber sheet) may be interposed between the drainage mechanism and the uppermost MEA.

  Details of the separator 10 shown in FIGS. 2 to 5 are shown in FIG. 6A is a plan view of the side disposed in the negative electrode diffusion layer where the oxygen channel 13 is not formed, FIG. 6B is a cross-sectional view taken along the line II in FIG. 6A, and FIG. 6C is the oxygen channel 13 formed. It is a top view of the side arrange | positioned at a positive electrode diffusion layer.

  In the separator 10, the fuel supply manifold 11 and the fuel discharge manifold 12 are arranged in the vicinity of two opposite sides of the four sides forming a quadrangle in a plan view. The fuel supply manifold and fuel discharge manifold of the separator are arranged as described above, and the fuel supply manifold and fuel discharge manifold formed in the MEA positive electrode, negative electrode and solid polymer electrolyte membrane, and the drainage mechanism are separated from the fuel supply manifold of the separator and By forming it at a position corresponding to the fuel discharge manifold, it is possible to take a larger area where the fuel flows in the negative electrode, that is, the area sandwiched between the fuel supply manifold and the fuel discharge manifold. It is possible to increase the area of the electrode that can be involved, thereby achieving more efficient power generation.

  Further, one side of the separator 10 is planar (FIG. 6A), and on the other side (FIG. 6C), as described above, the fuel supply manifold 11 and the fuel discharge manifold among the four sides forming a quadrangle in plan view are as described above. A plurality of oxygen flow paths 13 that linearly connect two sides other than the two opposite sides on which 12 is formed are formed in parallel or substantially parallel to each other. The oxygen channel 13 has a groove shape, and ribs 14 exist between adjacent oxygen channels. In FIG. 6C, in order to make it easy to distinguish the oxygen channel 13 and the rib 14, the oxygen channel 13 is shown with dots. In the oxygen flow path related to the separator, “parallel to or substantially parallel to each other” basically means that the respective oxygen flow paths are formed in parallel to each other. It is an acceptable meaning as long as the effect is not impaired.

  The length of the separator in the oxygen flow path direction (the length in the vertical direction in FIGS. 6A and 6C) is preferably 10 mm or more from the viewpoint of ensuring a sufficient electrode area. In addition, as described above, the air passing through the oxygen channel can be used as a cooling medium in addition to supplying oxygen (oxidant), but the separator is too long in the oxygen channel direction. Then, there is a possibility that the heat generated during power generation of the fuel cell cannot be sufficiently cooled by the air passing through the oxygen flow path. Therefore, the length of the separator in the oxygen flow path direction is preferably 100 mm or less.

  The distance between the fuel supply manifold and the fuel discharge manifold in the separator (the shortest distance; the same applies to the distance between the fuel supply manifold and the fuel discharge manifold) is 10 mm from the viewpoint of securing a sufficient electrode area. The above is preferable. Further, if the distance between the fuel supply manifold and the fuel discharge manifold is too long, the fuel flow path becomes long, and the pressure loss of the fuel flow may increase. For this reason, the distance between the fuel supply manifold and the fuel discharge manifold in the separator is preferably 300 mm or less.

  The width of the fuel supply manifold and the fuel discharge manifold in the separator (the length in the lateral direction in FIGS. 6A and 6C) is as large as possible within a range in which gas sealability can be secured in order to reduce the pressure loss during fuel flow. It is preferable to do.

  The fuel supply manifold and the fuel discharge manifold are provided in the vicinity of two opposite sides of the four sides of the rectangular separator in plan view. Specifically, the fuel supply manifold is shown in FIGS. 6A and 6C. In addition, it is preferable that the distance from the vertical side on the left side be as short as possible within a range in which gas sealing properties can be secured. In addition, it is preferable that the fuel discharge manifold be as short as possible from the vertical side on the right side within the range in which the gas sealability can be secured in FIGS. 6A and 6C.

  In the fuel cell of the present invention, the fuel supply manifold and the fuel discharge manifold formed in the MEA positive electrode, negative electrode and solid polymer electrolyte membrane, and the drainage mechanism correspond to the positions of the fuel supply manifold and the fuel discharge manifold of the separator. Place in place. Thereby, the fuel supply manifold of the separator, the MEA and the drainage mechanism overlaps, and the fuel discharge manifold of the separator, the MEA and the drainage mechanism overlaps, so that in the thickness direction of the fuel cell (stacking direction of the separator, MEA and drainage mechanism). A gas-liquid separation tube can be arranged and a fuel flow path is formed.

  In determining the formation positions of the fuel supply manifold and fuel discharge manifold of the positive electrode, the negative electrode, and the solid polymer electrolyte membrane of the MEA, the fuel supply manifold and fuel discharge manifold of the separator, and the fuel supply manifold and fuel discharge manifold of the drainage mechanism, It is preferable to consider the width of the gas seal in the positive electrode gas seal, the negative electrode gas seal, and the drainage mechanism described later.

  In the separator, the width of the oxygen channel (the length in the lateral direction in FIGS. 6B and 6C) is preferably 0.5 mm or more from the viewpoint of improving the air flow, and the strength of the separator. From the viewpoint of suppressing the decrease, the thickness is preferably 5 mm or less.

  The height of the oxygen channel (height of the groove) is preferably 0.5 mm or more from the viewpoint of improving air circulation, and 5 mm or less from the viewpoint of suppressing an increase in the thickness of the separator. It is preferable that

  The width of the rib between the oxygen channels (the length in the lateral direction in FIGS. 6B and 6C) is preferably 0.5 mm or more from the viewpoint of suppressing the strength reduction of the separator. From the viewpoint of improving the flow of air, it is preferable to set it to 5 mm or less.

  The thickness of the thinnest part of the oxygen channel portion (the length from the bottom of the oxygen channel to the other surface) is 0.2 mm or more from the viewpoint of ensuring the strength of the separator and preventing cracking, distortion, and the like. In view of suppressing an increase in the thickness of the separator, the thickness is preferably 5 mm or less.

  The separator material is not particularly limited as long as it has high electron conductivity and corrosion resistance. For example, graphite, a mixture of carbon and resin, stainless steel, stainless steel plated with gold or platinum, titanium Preferred are titanium plated with gold or platinum, stainless steel-copper clad, stainless steel-copper clad plated with gold or platinum, and the like.

  Details of the laminate 20a of the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer shown in FIGS. 2 to 5 are shown in FIG. 7A is a plan view, and FIG. 7B is a sectional view taken along line II-II in FIG. 7A.

  In the fuel cell, the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer constituting the MEA preferably have the same shape in plan view as shown in FIG. Thus, the thickness of the laminate composed of the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer can be made uniform, so that the separator (MEA) via the positive and negative electrode diffusion layers and the positive and negative electrode gas seals can be used. Tightening by the two separators disposed on both sides of the sheet becomes uniform, and gas leakage can be suppressed better. This also eliminates the need to accurately determine the positions of the positive electrode catalyst layer and the negative electrode catalyst layer across the solid polymer electrolyte membrane during the manufacture of the MEA, thereby making it possible to manufacture the MEA and thus the fuel cell. It becomes easy and the productivity can be increased.

  In FIG. 7A, the fuel supply manifold 201 and the fuel discharge manifold 202 are respectively formed in the vicinity of two opposing sides of the four sides of the stacked body 20a forming a quadrangle in a plan view.

  The positive electrode catalyst layer according to MEA of the fuel cell has a function of reducing oxygen diffused through the positive electrode diffusion layer. The positive electrode catalyst layer contains, for example, a carbon powder carrying a catalyst (catalyst-carrying carbon powder) and a proton conductive material, and further contains a binder such as a resin as necessary. Also good.

  The catalyst contained in the positive electrode catalyst layer is not particularly limited as long as it can reduce oxygen, and examples thereof include platinum fine particles. The catalyst may be fine particles composed of an alloy of platinum and at least one metal element selected from the group consisting of iron, nickel, cobalt, tin, ruthenium and gold.

As the carbon powder as the catalyst carrier, for example, carbon black having a BET specific surface area of 10 to 2000 m ² / g and an average particle diameter of 20 to 100 nm is used. The catalyst can be supported on the carbon powder by, for example, a colloid method.

  As a content ratio of the carbon powder and the catalyst, for example, the catalyst is preferably 5 to 400 parts by mass with respect to 100 parts by mass of the carbon powder. This is because such a content ratio can constitute a positive electrode catalyst layer having sufficient catalytic activity. In addition, for example, when the catalyst-supported carbon powder is produced by a method of depositing the catalyst on the carbon powder (for example, a colloid method), the catalyst diameter is as long as the carbon powder and the catalyst have the above content ratio. This is because it does not become too large and sufficient catalytic activity is obtained.

  The proton conductive material contained in the positive electrode catalyst layer is not particularly limited. For example, a resin having a sulfonic acid group such as a polyperfluorosulfonic acid resin, a sulfonated polyether sulfonic acid resin, or a sulfonated polyimide resin is used. be able to. Specific examples of the polyperfluorosulfonic acid resin include “Nafion (registered trademark)” manufactured by DuPont, “Flemion (registered trademark)” manufactured by Asahi Glass, and “Aciplex (trade name) manufactured by Asahi Kasei Kogyo Co., Ltd. Or the like.

  The content of the proton conductive material in the positive electrode catalyst layer is preferably 2 to 200 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. If the proton conductive material is contained in the above amount, sufficient proton conductivity is obtained in the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained. It is.

The binder for the positive electrode catalyst layer is not particularly limited. For example, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), fluoropolymers such as tetrafluoroethylene-ethylene copolymer (E / TFE), polyvinylidene fluoride (PVDF) and polychlorotrifluoroethylene (PCTFE), polyethylene, polypropylene, nylon, polystyrene, polyester, Non-fluorinated resins such as ionomer, butyl rubber, ethylene / vinyl acetate copolymer, ethylene / ethyl acrylate copolymer, and ethylene / acrylic acid copolymer can be used.

  The binder content in the positive electrode catalyst layer is preferably 0.01 to 100 parts by mass with respect to 100 parts by mass of the catalyst-supporting carbon powder. This is because if the binder is contained in the above-mentioned amount, sufficient binding properties can be obtained for the positive electrode catalyst layer, and the electric resistance value does not become too large, and a fuel cell with good battery performance can be obtained.

  The thickness of the positive electrode catalyst layer is preferably 1 to 50 μm.

  The negative electrode catalyst layer has a function of oxidizing a fuel such as hydrogen diffused through the negative electrode diffusion layer. The negative electrode catalyst layer contains, for example, a carbon powder carrying a catalyst (catalyst carrying carbon powder) and a proton conductive material, and may further contain a binder such as a resin if necessary. Good.

  The catalyst related to the negative electrode catalyst layer is not particularly limited as long as it can oxidize a fuel such as hydrogen. For example, each of the catalysts exemplified as the catalyst related to the positive electrode catalyst layer can be used. As for the carbon powder, proton conductive material, and binder related to the negative electrode catalyst layer, the above-described materials exemplified as the carbon powder, proton conductive material, and binder related to the positive electrode catalyst layer can be used.

  The thickness of the negative electrode catalyst layer is preferably 1 to 50 μm.

  The solid polymer electrolyte membrane is not particularly limited as long as it is made of a material that can transport protons and does not exhibit electronic conductivity. Examples of materials that can constitute the solid polymer electrolyte membrane include polyperfluorosulfonic acid resin, specifically, “Nafion (registered trademark)” manufactured by DuPont, and “Flemion (registered trademark)” manufactured by Asahi Glass. “Aciplex (trade name)” manufactured by Asahi Kasei Corporation. In addition, sulfonated polyether sulfonic acid resin, sulfonated polyimide resin, sulfuric acid-doped polybenzimidazole, and the like can also be used as the material for the solid polymer electrolyte membrane.

  The thickness of the solid polymer electrolyte membrane is preferably 5 to 150 μm.

  The rubber sheet 52 shown in FIG. 4 can have the same planar shape as, for example, the laminate 20a shown in FIG. 7A. Therefore, it is preferable to form the fuel supply manifold and the fuel discharge manifold in the rubber sheet 52 at positions corresponding to the fuel supply manifold and the fuel discharge manifold of the separator, for example.

  Details of the positive electrode diffusion layer and the positive electrode gas seal shown in FIGS. 2 to 5 are shown in FIG. 8A is a plan view, and FIG. 8B is a sectional view taken along line III-III in FIG. 8A. As described above, the positive electrode diffusion layer 21 is disposed so as to cover the entire surface of the separator in which the oxygen flow path is formed.

  A positive electrode gas seal 30 for suppressing the outflow of the fuel gas is arranged outside two sides (two vertical sides in FIG. 8A) parallel to or substantially parallel to the oxygen flow path of the separator in the positive electrode diffusion layer 21. The fuel supply manifold 31 and the fuel discharge manifold 32 are preferably formed on the positive electrode gas seal 30. When the positive electrode gas seal is arranged as described above, since the positive electrode gas seal does not exist at the position corresponding to the open end of the oxygen flow path of the separator, the expansion and contraction of the solid polymer electrolyte membrane that may be caused by the pressure or moisture caused by the fuel The stress of can be relieved.

  The position of the interface between the positive electrode diffusion layer 21 and the positive electrode gas seal 30 is preferably set to a position corresponding to the outer side (fuel supply manifold side and fuel discharge manifold side) of the oxygen flow path forming part of the separator. If the interface exists at a position corresponding to the oxygen flow path of the separator or a position of a rib corresponding to the oxygen flow path and the oxygen flow path adjacent to the oxygen flow path, the gas sealing performance may be deteriorated. There is.

  The width of the positive electrode gas seal (the length of a and b in FIG. 8A) is preferably 0.5 mm or more from the viewpoint of improving the gas sealability, and also reduces the loss of the electrode area. From the viewpoint, it is preferably 5 mm or less.

  The thickness of the positive electrode diffusion layer is preferably 100 to 1000 μm. Moreover, it is preferable that the thickness of a positive electrode gas seal is 50-1000 micrometers.

  4 and 5, the layer formed of the current collector plate 50 and the gas seal 51 can have the same planar shape as, for example, the layer formed of the positive electrode diffusion layer 21 and the gas seal 30 illustrated in FIG. 8A. . That is, the positive electrode diffusion layer 21 in FIG. 8A can be replaced with the current collector plate 50, and the gas seal 30 can be replaced with the gas seal 51. Therefore, in plan view, the gas seals 51, 51 disposed at the opposite ends of the current collector 50 are respectively disposed at positions corresponding to, for example, the fuel supply manifold and the fuel discharge manifold of the separator. Preferably a manifold is formed.

  Details of the negative electrode diffusion layer and the negative electrode gas seal shown in FIGS. 2 to 5 are shown in FIG. 9A is a plan view, and FIG. 9B is a sectional view taken along line IV-IV in FIG. 9A. In the fuel cell, the separator is disposed so that the negative electrode diffusion layer 25 is in contact with the plane of the separator (the surface opposite to the surface on which the oxygen channel is formed).

  In the fuel cell of the present invention, as shown in FIG. 9, a negative electrode gas seal 40 for suppressing the outflow of fuel gas is disposed outside the outer periphery of the rectangular negative electrode diffusion layer 25 in plan view. A fuel supply manifold 41 is formed by one of the four sides constituting the quadrangle (the vertical side on the left side in FIG. 9A) and the negative electrode gas seal 40, and faces the one side of the negative electrode diffusion layer 25. The fuel discharge manifold 42 is preferably formed by one side (the vertical side on the right side in FIG. 9A) and the negative gas seal 40.

  As described above, the negative electrode diffusion layer 25 is generally made of a material having pores through which fuel gas can flow, but the negative electrode diffusion layer 25, the negative electrode gas seal 40, the fuel supply manifold 41, and the like. By disposing the fuel discharge manifold 42 as described above, a fuel flow path from the fuel supply manifold 41 to the fuel discharge manifold 42 is formed in the entire negative electrode diffusion layer 25, enabling stable power generation. Become.

  As shown in FIG. 9A, the negative electrode diffusion layer 25 does not need to be formed with a fuel flow path, and as a result, the entire surface comes into contact with the separator, so that the electrical contact resistance can be minimized. It becomes possible.

  The width of the negative electrode gas seal (the length of c and d in FIG. 9A) is preferably 0.5 mm or more from the viewpoint of improving the gas sealability, and also reduces the loss of the electrode area. From the viewpoint, it is preferably 5 mm or less.

  The thickness of the negative electrode diffusion layer is preferably 100 to 1000 μm. Moreover, it is preferable that the thickness of a negative electrode gas seal is 50-1000 micrometers.

  The positive electrode diffusion layer and the negative electrode diffusion layer are made of a porous electron conductive material, and for example, a porous carbon sheet subjected to a water repellent treatment is used. A carbon powder paste containing fluororesin particles (such as PTFE resin particles) is applied to the positive electrode diffusion layer and the catalyst layer side of the negative electrode diffusion layer for the purpose of further improving water repellency and improving the contact property with the catalyst layer. May be.

  As materials for the positive electrode gas seal and the negative electrode gas seal, various materials known as seal materials in the field of fuel cells, for example, silicon rubber, ethylene-propylene-diene rubber, PTFE film, polyimide film, and the like can be used.

  Details of the drainage mechanism shown in FIG. 4 are shown in FIG. 10A is a plan view, FIG. 10B is a cross-sectional view taken along line VV in FIG. 10A, and FIG. 10C is a cross-sectional view taken along line VI-VI in FIG. 10A. As described above, the drainage mechanism is disposed above the uppermost MEA in the stacked MEA group.

  As shown in FIG. 10, in the drainage mechanism, the gas seal 60b for suppressing gas in / out is disposed outside the outer periphery of the quadrilateral water passage layer 60a in plan view, thereby forming the quadrangular shape of the water passage layer 60a. The fuel supply manifold 61 is formed by one of the four sides (the vertical side on the left side in FIG. 10A) and the gas seal 60b, and one side (FIG. 10A) facing the one side of the water passage layer 60a. It is preferable to form the fuel discharge manifold 62 with the middle right vertical side) and the gas seal 60b. Further, on each side surface of the water passage layer 60a on the fuel supply manifold 61 side and the fuel discharge manifold 62 side, a seal plate 60c for suppressing the outflow of water is disposed. An opening 60d for connecting the separation tube to the water passage layer 60a is preferably provided.

  The water passage layer 60a preferably has the same structure as the negative electrode diffusion layer of the MEA. That is, the drainage mechanism preferably has the same structure as the layer constituted by the negative electrode diffusion layer and negative electrode gas seal of the MEA. Since the drainage mechanism has such a structure, as described above, the drainage mechanism has a pressure loss equivalent to that of the MEA that hits the power generation unit, so that the power generation efficiency of the fuel cell can be maintained high.

  Therefore, the water passage layer according to the drainage mechanism is preferably made of a porous electron conductive material, like the negative electrode diffusion layer, and for example, a porous carbon sheet subjected to a water repellent treatment is preferably used. It is done. By configuring the water passage layer with such a material, water (intrusion water in the fuel cell) can pass through the inside of the layer satisfactorily, so there is no need to separately form a water passage groove or the like. For the purpose of further improving water repellency, a carbon powder paste containing fluororesin particles (such as PTFE resin particles) may be applied to the surface of the water passage layer.

  The thickness of the water passage layer is preferably 100 to 1000 μm, like the negative electrode diffusion layer.

  For the gas seal disposed on the outer periphery of the water passage layer, as well as the negative electrode gas seal, various materials known as sealing materials in the fuel cell field etc., for example, silicon rubber, ethylene-propylene-diene rubber, PTFE film, polyimide A film or the like can be used.

  The width of the gas seal disposed on the outer periphery of the water passage layer (the length of e and f in FIG. 10A) is preferably 0.5 mm or more and 5 mm or less, similarly to the negative electrode gas seal. Moreover, it is preferable that the thickness of the gas seal arrange | positioned on the outer periphery outer periphery of a water passage layer is 50-1000 micrometers similarly to a negative electrode gas seal.

  The material of the seal plate disposed on the side surface of the water passage layer on the manifold side is not particularly limited as long as it does not transmit water, and a resin plate such as an acrylic plate can be used. The thickness of the seal plate is not particularly limited, and may be, for example, 50 to 1000 μm.

  The drainage mechanism has the same area in plan view as the separator interposed between the MEAs, thereby facilitating the production of the fuel cell including the drainage mechanism. ”Is only required to be substantially the same. When stacking each layer of the fuel cell including the drainage mechanism and the separator, detailed alignment is required. Although it is the meaning to accept | permit, specifically, the area of a drainage mechanism should just be about 95 to 105% with respect to the area of a separator.

  FIG. 11 shows the gas-liquid separation tube shown in FIGS. 4 and 5 and the connection state between the gas-liquid separation tube and the drainage mechanism. 11A is a side view of the main part of the gas-liquid separation tube, and FIG. 11B is a perspective view of the main part in a state where the gas-liquid separation tube is connected to the drainage mechanism.

  1-10 mm is preferable and, as for the internal diameter of a gas-liquid separation tube, 1-5 mm is more preferable. If the inner diameter is less than 1 mm, the pressure inside the tube will increase, so that the water pressure of the gas-liquid separation tube may be exceeded and the water-liquid separation tube may leak. There is a tendency to form a puddle, and it may be difficult to efficiently send ingress water to the drainage mechanism.

  Further, the water pressure resistance of the gas-liquid separation tube is preferably 10 kPa or more. If it is less than 10 kPa, since water leaks easily from the gas-liquid separation tube, flooding is likely to occur. The upper limit of the water pressure resistance is not particularly limited, but is preferably 10 to 100 kPa, although it depends on the material of the gas-liquid separation tube.

  Although FIG. 11B shows an example in which the gas-liquid separation tube is connected to the substantially central portion of the seal plate, the connection position is not limited to the central portion of the seal plate, and may be a side portion.

  As the material of the gas seal 51 in the layer composed of the current collector 50 and the gas seal 51 shown in FIGS. 4 and 5, various materials known as seal materials in the field of fuel cells and the like as well as the negative electrode gas seal and the positive electrode gas seal. For example, silicon rubber, ethylene-propylene-diene rubber, PTFE film, polyimide film, or the like can be used. Further, silicon rubber or ethylene-propylene-diene rubber can be used as the material of the rubber sheet 52 shown in FIG.

  In the fuel cell of the present invention, in the MEA constituting the fuel cell, the positive electrode and the negative electrode may be configured to be conductive, for example, by connecting them with a lead body via a resistor and a switch. preferable. In the fuel cell having the MEA having such a configuration, when the power generation by the fuel cell is finished, the positive electrode and the negative electrode related to the MEA are short-circuited by, for example, turning on the above-described fuel, and the fuel such as hydrogen remaining in the fuel cell. Can be consumed. Therefore, deterioration of the fuel cell due to fuel remaining in the fuel cell at the end of power generation by the fuel cell can be suppressed.

  In the MEA related to the fuel cell, when the positive electrode and the negative electrode are configured to be conductive through the resistance as described above, examples of the resistance include a system (fuel cell power generation system) having the fuel cell of the present invention. ), After stopping the fuel cell, it is sufficient to use one having a resistance value such that the time required for the voltage between the positive electrode and the negative electrode of the MEA to be 0.1 V or less is within 1 minute, without using the resistance. However, if the voltage between the positive electrode and the negative electrode of the MEA can be lowered as described above in such a time, it is possible to conduct by connecting with a lead body or the like only through a switch without using a resistor. Also good.

  FIG. 12 schematically shows an example of a fuel cell power generation system using the fuel cell of the present invention. In FIG. 12, reference numeral 100 denotes a fuel cell (a fuel cell of the present invention), and 600 denotes a hydrogen supply source for supplying hydrogen as a fuel to the fuel cell 100. The hydrogen supply source 600 is a hydrogen production apparatus having a hydrogen generation container 603 that contains a hydrogen generating substance 604 and a water container 601 that contains water 602. When the water 602 is supplied from the water container 601 to the hydrogen generation container 603 through the pipes 501 and 502 using the pump 201, hydrogen is generated by the reaction between the hydrogen generating substance 604 and the water 602. Condensed water separator) 801 and pipes 504, 505 and 506 are supplied to the fuel cell 100.

  Reference numeral 101 denotes a blower fan for supplying air to the positive electrode of the fuel cell 100, supplying air to the hydrogen consuming device 900, and cooling the fuel cell 100. Moreover, the arrow in FIG. 12 has shown the direction of the flow of the air sent by the ventilation fan 101 (it is the same also in FIG. 14 and FIG. 15 mentioned later). As shown in FIG. 12, the fuel cell power generation system using the fuel cell of the present invention preferably has a blower fan 101.

  The fuel cell power generation system shown in FIG. 12 has exhaust means for discharging the gas in the fuel cell 100 to the outside of the system, and the exhaust means intermittently discharges the gas in the fuel cell 100 to the outside of the fuel cell 100. And a purge valve 310 for discharging the hydrogen gas and a hydrogen consuming device 900 for consuming hydrogen in the gas discharged from the fuel cell 100.

  The exhaust means according to the fuel cell power generation system shown in FIG. 12 includes a pipe 507, a pressure sensor 400, a purge valve 310, a pipe 509, a water container 601, a pipe 510, a hydrogen consumption device 900, and a pipe 514.

  In the fuel cell power generation system shown in FIG. 12, as power is generated by the fuel cell 100, a gas (residual hydrogen not involved in power generation and an impure gas diffused from the positive electrode during power generation) Etc.), and intruded water in the fuel cell 100 is discharged to the pipe 507 side by the drainage mechanism and the gas-liquid separation tube. The inside of the fuel cell 100 and the pipe 507 are discharged by these gases and infiltrated water. When the internal pressure rises to some extent, the purge valve 310 can discharge the gas and the ingress water to the pipe 509 side. As described above, the gas and intrusion water in the fuel cell 100 can be intermittently discharged out of the fuel cell 100 by the action of the purge valve 310.

  The system shown in FIG. 12 includes a pressure sensor 400. While the pressure sensor 400 measures the pressure in the pipe 507, the purge valve 310 is opened in a timely manner so that the gas and the intruded water of the fuel cell 100 are supplied to the pipe 509 side. Can be discharged. Thus, in the fuel cell power generation system, it is preferable to control the opening / closing operation of the purge valve 310 based on the pressure information obtained by measuring the pressure on the negative electrode side of the fuel cell 100 with the pressure sensor 400. The purge valve is desirably controlled so as to open and close when the pressure difference between the pressure of the negative electrode in the fuel cell and the external pressure (for example, atmospheric pressure) reaches 5 to 300 kPa. When the pressure difference is less than 5 kPa, the pressure difference is too small and the ability to discharge water is reduced. When the pressure difference does not open until the pressure exceeds 300 kPa, the internal pressure becomes too high and the MEA may be damaged. .

  With the configuration as described above, it is possible to appropriately generate power while measuring pressure information in the fuel cell, so that the pressure becomes too high and hydrogen leaks from the fuel cell or the fuel cell bursts. Can be suppressed. In addition, it is possible to generate power so that the output can be properly maintained in consideration of the output state of the fuel cell and the pressure information.

  In the system shown in FIG. 12, gas and water (intrusion water) discharged from the fuel cell 100 are introduced from the pipe 509 to the water container 601 of the hydrogen supply source 600. Since the water container 601 also acts as a water trap, the water discharged from the fuel cell 100 is collected by the water container 601. As described above, in the fuel cell power generation system, in order to recover water (intrusion water) contained in the gas discharged from the fuel cell, a water recovery means such as a water trap is provided between the purge valve and the hydrogen consuming device. It is preferable to provide. With such a configuration, the water can be supplied to the hydrogen consuming device after removing water from the gas discharged from the fuel cell, so that the hydrogen consumption efficiency is reduced due to the accumulation of water in the hydrogen consuming device. Can be suppressed, and more efficient hydrogen removal can be achieved.

  In the fuel cell power generation system, it is preferable to use the water (intrusion water) in the fuel cell recovered by the water recovery means for the reaction with the hydrogen generating substance (that is, the production of hydrogen). In the system of FIG. 12, since the water container 601 of the hydrogen supply source 600 also serves as a water recovery means, the water discharged from the fuel cell 100 can be used as water for hydrogen production. With such a configuration, the system can be made compact and the energy utilization rate can be increased.

  In the system shown in FIG. 12, gas from which water (intrusion water) has been removed by the water container 601 (gas discharged from the fuel cell 100) is introduced into the hydrogen consuming apparatus 900 through the pipe 510. The hydrogen consuming apparatus 900 of FIG. 12 has an MEA (not shown) and consumes hydrogen in the gas by the same mechanism as the power generation by the MEA of the fuel cell 100. A pipe 514 connected to the hydrogen consuming apparatus 900 is in contact with outside air, and the gas from which hydrogen has been removed by the hydrogen consuming apparatus 900 is discharged out of the system through the pipe 514. In the system shown in FIG. 12, the outlet of the pipe 514 is arranged so as to be blown from the blower fan 101, so that even if hydrogen remains slightly without being processed by the hydrogen consuming device, it is diluted. Can be discharged out of the system.

  In a fuel cell, in general, when power generation is stopped, deterioration occurs when the state where air is stored in the positive electrode and hydrogen is stored in the negative electrode in the fuel cell continues for a long time. The cause of this is not clear, but in this case, since the voltage is maintained in a higher state than during power generation, it is presumed that the positive and negative carbon and catalyst are oxidized. Therefore, the fuel cell power generation system may be configured to prevent hydrogen from entering the fuel cell at the end of power generation or may be configured to remove hydrogen remaining in the fuel cell. preferable.

  In the system shown in FIG. 12, a three-way valve 302 is provided between a pipe 504 and a pipe 505 for introducing hydrogen from the hydrogen supply source 600 into the fuel cell. Furthermore, this pipe 511 is connected to a pipe 510 installed between the water container 601 and the hydrogen consuming apparatus 900. Therefore, at the end of power generation of the fuel cell 100, the three-way valve 302 is operated to supply the hydrogen from the hydrogen supply source 600 directly to the hydrogen consuming device 900 through the pipes 511 and 510 without being sent to the fuel cell 100. Can be processed. Thus, in the system shown in FIG. 12, when power generation by the fuel cell 100 is completed, hydrogen can be prevented from entering the fuel cell 100 and deterioration of the fuel cell 100 due to the hydrogen can be suppressed.

  In the system shown in FIG. 12, a three-way valve 301 is connected to pipes 501 and 502 that connect a water container 601 and a hydrogen generation container 603 of the hydrogen supply source 600, and the three-way valve 301 is connected to a pipe 512. Are also connected. Further, the pipe 512 is also connected to a pipe 505 and a pipe 506 for supplying hydrogen from the hydrogen supply source 600 to the fuel cell 100 via the three-way valve 303. Therefore, at the end of power generation of the fuel cell 100, the three-way valves 301 and 303 are operated, and the purge valve 310 is further operated, so that the water in the water container 601 can be supplied into the fuel cell 100 through the pipe 512 and the pipe 506. Accordingly, in the system shown in FIG. 12, hydrogen remaining in the fuel cell 100 can be replaced with water at the end of power generation by the fuel cell 100, so that the hydrogen remains in the fuel cell 100. Therefore, the deterioration of the fuel cell 100 can also be suppressed.

  Further, as described above, since water can be stored in the fuel cell 100 at the end of power generation by the fuel cell 100, the solid polymer electrolyte membrane in the MEA of the fuel cell 100 is kept in a wet state. Is possible. Generally, in a polymer electrolyte fuel cell, if it is stopped for a long time, the polymer electrolyte membrane is dried, but in such a state, self-wetting by power generation is required at the time of restart, and the output is reduced. It takes time to get up. However, in the system shown in FIG. 12, since the fuel cell 100 can be filled with water at the end of power generation by the fuel cell 100 as described above, the solid polymer electrolyte membrane is prevented from being dried, and the initial state when restarting is performed. Therefore, it becomes possible to demonstrate a high output.

  Furthermore, in the system shown in FIG. 12, since water supplied into the fuel cell 100 at the end of power generation can be supplied from the water container 601 of the hydrogen supply source 600, there is no need to provide a separate water container or the like. can do. The water supplied into the fuel cell at the end of power generation may be supplied directly from the water recovery means (water trap).

  In the fuel cell power generation system using the fuel cell of the present invention, as a hydrogen supply source for supplying hydrogen to the fuel cell, as shown in FIG. 12, hydrogen generated by the reaction between the hydrogen generating substance and water is supplied. It is preferable that the hydrogen production apparatus have a mechanism for

  The hydrogen production apparatus (hydrogen supply source) 600 according to the system shown in FIG. 12 includes the hydrogen generation container 603 and the water container 601 as described above. The hydrogen generating container 603 contains a hydrogen generating substance 604. Water 602 is supplied from the water container 601 to the hydrogen generating container 603, and the hydrogen generating substance 604 and the water 602 are reacted in the hydrogen generating container 603 to produce hydrogen. Hydrogen generated in the hydrogen generation container 603 is supplied to the fuel cell 100 through a fuel flow path including pipes 503, 504, 505, and 506.

  A water supply pump 201 is provided in the pipes 501 and 502 for supplying water from the water container 601 to the hydrogen generation container 603. The water stored in the water container 601 may be a liquid containing at least water, such as neutral water, an acidic aqueous solution, or an alkaline aqueous solution, and may be selected according to the reactivity with the hydrogen generating material used. That's fine.

  The hydrogen generation container 603 and the water container 602 may be detachable. As a result, when the hydrogen generating material in the hydrogen generating container 603 is completely consumed or when the water in the water container 602 is exhausted, these are removed and the hydrogen generating container 603 filled with the hydrogen generating material or water is filled. By newly attaching the water container 602, hydrogen production can be performed again.

  The hydrogen generating material accommodated in the hydrogen generating vessel 603 is not particularly limited, but is preferably a substance capable of generating hydrogen by reacting with water at a low temperature of 120 ° C. or lower. For example, a metal such as aluminum, silicon, zinc, magnesium; one or more elements selected from aluminum, silicon, zinc, and magnesium are contained in an amount of 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more. Alloys, metal hydrides, and the like can be preferably used.

  The hydrogen generating material composed of the above metal or alloy is stabilized by forming an oxide film on the surface. For this reason, in order to increase the reactivity, it is preferable to make the particle size of the hydrogen generating material as small as possible and increase the reaction area. For example, the average particle diameter of the hydrogen generating substance particles is preferably 100 μm or less, and more preferably 50 μm or less. Further, the particle shape is preferably flaky in order to increase the reaction efficiency. If the particle size is too small, the bulk density is reduced, the packing density is lowered, and handling becomes difficult. Therefore, the particle size of the hydrogen generating material is preferably 0.1 μm or more.

  As a method for measuring the average particle diameter, for example, a laser diffraction / scattering method or the like can be used. Specifically, this is a particle diameter distribution measurement method using a scattering intensity distribution detected by irradiating a measurement target substance dispersed in a liquid phase such as water with laser light. As a particle size distribution measuring apparatus using a laser diffraction / scattering method, for example, “Microtrack HRA” manufactured by Nikkiso Co., Ltd. can be used.

  Examples of the metal hydride that can be used as the hydrogen generating substance include sodium borohydride and potassium borohydride. These metal hydrides are relatively stable in an aqueous alkali solution, but when a catalyst is present, they can rapidly react with water to generate hydrogen. As the catalyst, for example, metals such as Pt and Ni, acids, and the like can be used.

  As the hydrogen generating substance, those exemplified above may be used alone or in combination of two or more.

  In order to increase the reactivity with water, the hydrogen generating substance may be heated in a state of being mixed with water, or heated water may be supplied.

  In addition, by using the above hydrogen generating material together with a heat generating material that generates heat by reacting with water (a material other than the hydrogen generating material), even if low temperature water (for example, about 5 ° C.) is supplied, Heat generation increases the temperature in the reaction system, enabling rapid hydrogen generation.

  The exothermic substance that generates heat by reacting with water, for example, calcium oxide, magnesium oxide, calcium chloride, magnesium chloride, calcium sulfate, etc., becomes a hydroxide by reaction with water, or generates heat when hydrated. Examples include alkali metal or alkaline earth metal oxides, chlorides, sulfate compounds, and the like. In addition, those that generate hydrogen by reaction with water, such as metal hydrides such as sodium borohydride, potassium borohydride, and lithium hydride, can be used as a hydrogen generating substance as described above. However, it can also be used as a heat generating material when the above metal or alloy is used as a hydrogen generating material.

  In particular, when a metal such as aluminum, silicon, zinc, or magnesium or an alloy mainly composed of one or more elements selected from aluminum, silicon, zinc, and magnesium is used as the hydrogen generating substance, the above exothermic substance is used. It is preferable to use together. On the other hand, when the metal hydride is used as a hydrogen generating substance, hydrogen can be produced at a relatively good rate without using the exothermic substance. May be increased.

  The material and shape of the hydrogen generation container 603 are not particularly limited as long as a hydrogen generating substance that generates hydrogen can be stored. However, a material and shape that do not leak water and hydrogen are preferable. As a specific material of the container, a material that does not easily transmit water and hydrogen and that does not break even when heated to about 120 ° C. is preferable. For example, a metal such as aluminum or iron, or a resin such as polyethylene or polypropylene may be used. Can be used. Further, as the shape of the container, a prismatic shape, a cylindrical shape or the like can be adopted.

  There is no restriction | limiting in particular about the water container 601, For example, the tank etc. which accommodate the water similar to what is used for the conventional hydrogen production apparatus are employable.

  When water in the water container 601 is supplied to the hydrogen generation container 603 through the pipes 501 and 502, it reacts with the hydrogen generating substance in the hydrogen generation container 603 to generate hydrogen, but is present in the hydrogen generation container 603. In some cases, unreacted water is mixed into the generated hydrogen, and the mixture of these flows into the fuel cell 100 through the fuel flow path including the pipe 503 and the like.

  Therefore, the hydrogen production apparatus (hydrogen supply source) 600 is preferably provided with a condensed water separator (water trap) 801 in the middle of the fuel flow path for supplying hydrogen to the fuel cell. As shown in FIG. 12, the hydrogen gas discharged from the hydrogen generation vessel 603 is introduced into the condensed water separator 801 through the pipe 503. During this time, the water contained in the hydrogen gas is cooled in the pipe 503 and becomes condensed water. Since condensed water falls to the lower part of the condensed water separator 801 by gravity, hydrogen gas can be separated from water. The separated hydrogen gas is supplied to the fuel cell 100 through the pipe 504 and the like.

  In addition, as shown in FIG. 12, if the condensed water separator 801 and the water container 601 are connected by a water recovery pipe 513, the water separated by the condensed water separator 801 can be recovered in the water container 601. By recovering the separated water, the water supplied for hydrogen generation can be used efficiently, and the water container 601 can be made more compact. A water recovery pipe 513 connecting the condensed water separator 801 and the water container 601 may be provided with a pump 202 for sending water as shown in FIG.

  The hydrogen consuming apparatus according to the fuel cell power generation system is not particularly limited as long as it can consume and remove the hydrogen in the system. And a device having a catalyst capable of oxidizing hydrogen.

  As an apparatus for consuming hydrogen by the same mechanism as the power generation by the MEA related to the fuel cell, specifically, like the MEA constituting the fuel cell shown in FIGS. 2 to 5, a positive electrode diffusion layer, a positive electrode catalyst layer, Hydrogen consumption having MEA having a configuration in which a solid polymer electrolyte membrane, a negative electrode catalyst layer, and a negative electrode diffusion layer are sequentially laminated, and the positive electrode and the negative electrode are connected so as to be conductive through, for example, a switch and a resistor Apparatus.

  Regarding the positive electrode diffusion layer, the positive electrode catalyst layer, the solid polymer electrolyte membrane, the negative electrode catalyst layer, and the negative electrode diffusion layer according to the MEA of the hydrogen consuming apparatus, the positive electrode diffusion layer, the positive electrode catalyst layer, and the solid polymer electrolyte membrane according to the MEA of the fuel cell As the negative electrode catalyst layer and the negative electrode diffusion layer, the same ones as described above can be used.

  In the case of the hydrogen consuming apparatus described above, when it is necessary to consume hydrogen in the gas, a switch is made at the connection between the positive electrode and the negative electrode, and conduction between the positive electrode and the negative electrode of the MEA is performed. Can be consumed. This completely eliminates hydrogen in the gas that is exhausted from the fuel cell and needs to be discharged outside the system, and hydrogen that enters the fuel cell from the hydrogen supply source at the end of power generation by the fuel cell, Alternatively, the amount of hydrogen can be greatly reduced.

  In the hydrogen consuming apparatus having the above MEA, when the positive electrode and the negative electrode of the MEA are connected via a resistor, the resistance is, for example, between the positive electrode and the negative electrode of the MEA after hydrogen is introduced into the hydrogen consuming device. It is sufficient to use a resistor having such a resistance value that the time required for the voltage to be 0.1 V or less is within one minute. Moreover, if the voltage between the positive electrode and the negative electrode of the MEA can be lowered as described above without using a resistor, the positive electrode and the negative electrode of the MEA are only switches without using a resistor. It is good also as a conduction | electrical_connection by connecting with a lead body etc. via this.

  As described above, since the hydrogen consuming apparatus includes the MEA similarly to the fuel cell, for example, a fuel cell having a plurality of MEAs (stack) is used, and a part of the MEAs (for example, one, The fuel cell and the hydrogen consuming apparatus can be integrated with each other in a form in which two, three, etc.) are used as the hydrogen consuming apparatus.

  The fuel cell power generation system shown in FIG. 12 includes an integrated product of the fuel cell 100 and the hydrogen consuming apparatus 900. FIG. 13 is a perspective view schematically showing an example of the integrated product. In FIG. 13, parts common to FIG. In the integrated product shown in FIG. 13, among the plurality of MEAs 20 stacked via the separator 10, the lower part constitutes the fuel cell 100 and the upper part constitutes the hydrogen consuming apparatus 900. Reference numeral 81 denotes a gas supply port of the hydrogen consuming apparatus 900, which is connected to, for example, a pipe 510 in FIG. Reference numeral 91 denotes a gas discharge port of the hydrogen consuming apparatus 900, which is connected to, for example, a pipe 514 in FIG.

  By configuring the fuel cell power generation system using an integrated body of the fuel cell and the hydrogen consuming device, the system can be more easily downsized. In this case, the MEA used as a hydrogen consuming device is not connected to the MEA used for power generation, and the gas from which hydrogen has been removed by the hydrogen consuming device can be efficiently exhausted out of the system, and power can be generated efficiently. The MEA used as the hydrogen consuming device and the MEA used for power generation are configured so that the internal gas cannot pass back and forth.

  FIG. 14 shows a schematic diagram of another example of the fuel cell power generation system using the fuel cell of the present invention. In FIG. 14, the same parts as those of the fuel cell power generation system shown in FIG. In the fuel cell power generation system shown in FIG. 14, a pipe 505 for supplying hydrogen from the hydrogen supply source 600 to the fuel cell 100 and a three-way valve 303 connected to the pipe 506 are further provided with a pipe 515 for taking outside air. It is connected. At the end of power generation by the fuel cell 100, the three-way valve 303 is operated so that air can be taken into the fuel supply port of the fuel cell 100 through the pipe 515. Further, although not shown, the MEA in the fuel cell 100 is configured so that the positive electrode and the negative electrode can conduct as described above, and while taking air into the fuel cell 100, the positive electrode and the negative electrode The hydrogen remaining in the fuel cell 100 can be consumed.

  In the fuel cell power generation system shown in FIG. 14, by the action by taking air into the fuel supply port of the fuel cell 100 and the action by short-circuiting the positive electrode and the negative electrode of the MEA of the fuel cell 100. At the end of power generation by the fuel cell, deterioration of the fuel cell due to hydrogen remaining in the fuel cell can be suppressed.

  FIG. 15 shows a schematic diagram of another example of the fuel cell power generation system using the fuel cell of the present invention. In FIG. 15, the same parts as those of the fuel cell power generation system shown in FIG. The fuel cell power generation system shown in FIG. 15 is an example provided with a hydrogen consuming apparatus 900 having a catalyst capable of oxidizing hydrogen. The hydrogen consuming apparatus 900 is disposed at a position where the air sent from the blower fan 101 can be taken in, and is configured to efficiently consume hydrogen in a small space. Therefore, the fuel cell power generation system having the configuration shown in FIG. 15 can be easily downsized.

  Examples of the hydrogen consuming apparatus having a catalyst that can oxidize hydrogen include a filter containing the catalyst, a cylinder-shaped exterior body filled with the catalyst, and the like. As the catalyst capable of oxidizing hydrogen, for example, various catalysts exemplified above as the catalyst in the negative electrode catalyst layer of MEA can be used.

  So far, the fuel cell of the present invention and the fuel cell power generation system using the fuel cell of the present invention have been described with reference to FIGS. 1 to 15. However, FIGS. The fuel cell power generation system using the fuel cell and only some of the components usable in the system are shown. The fuel cell of the present invention and the fuel cell power generation system using the fuel cell of the present invention However, the present invention is not limited to those shown in these drawings or those having the components shown in these drawings.

  Hereinafter, the present invention will be described in detail based on examples. However, the following examples do not limit the present invention.

Example 1
A fuel cell having the same structure as that shown in FIG. 1 was produced. For the laminate of the positive electrode catalyst layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer, the one shown in FIG. 7 was used. “Nafion (registered trademark) 112” manufactured by DuPont was used for the solid polymer electrolyte membrane 23. Pt-supported carbon (“TEC10E50E” manufactured by Tanaka Kikinzoku Co., Ltd.) and a 5 mass% Nafion solution (manufactured by Aldrich) were mixed in a predetermined amount, and this was applied to one side of a polytetrafluoroethylene sheet and dried. . The polytetrafluoroethylene sheet is stacked on both sides of the solid polymer electrolyte membrane so that the coated surface of the mixture of Pt-supported carbon and Nafion solution is on the solid polymer electrolyte membrane side, and hot-pressed to form a positive electrode catalyst. A laminate of the layer, the solid polymer electrolyte membrane, and the negative electrode catalyst layer was obtained. Thereafter, the laminate was cut out so that the outer shape was 24 mm × 85.5 mm.

  “GDL10DC” (thickness: 470 μm) manufactured by SGL Carbon was cut into a size of 24 mm × 71.5 mm and used for the positive electrode diffusion layer. Further, two 24 mm × 7 mm silicon rubber sheets (thickness 0.3 mm) were prepared for the positive electrode gas seal, and holes (fuel supply manifold and fuel discharge manifold) each having a width of 20 mm × width 3 mm were formed.

  The negative electrode gas seal uses the same silicon rubber sheet as the positive electrode gas seal, has a size of 24 mm × 85.5 mm, and has a width of 20 mm for inserting a negative electrode diffusion layer and constituting a fuel supply manifold and a fuel discharge manifold. X A hole having a size of 81.5 mm in width was formed. For the negative electrode diffusion layer, the same material as that used for the positive electrode diffusion layer was used, and cut into a size of 20 mm × 75.5 mm.

  Twelve MEAs were produced by laminating the above laminate, positive electrode diffusion layer, positive electrode gas seal, negative electrode diffusion layer, and negative electrode gas seal in the order and arrangement shown in FIG.

  A separator made of carbon (thickest portion has a thickness of 2 mm) and having the configuration shown in FIG. 6 was used. The outer shape was 24 mm × 85.5 mm, and the sizes of the fuel supply manifold 11 and the fuel discharge manifold 12 were 20 mm wide × 3 mm wide. The oxygen flow path (oxygen flow path that also serves as a cooling medium flow path) 13 had a width of 1.5 mm and a depth of 1.5 mm, and the rib 14 between the oxygen flow paths had a width of 1 mm.

  For the gas seal of the drainage mechanism, the same silicon rubber sheet as the negative electrode gas seal is cut out to the same size as the negative electrode gas seal, and further, a water passage layer is inserted and a fuel supply manifold and a fuel discharge manifold are configured to be 20 mm wide. X A hole having a size of 81.5 mm in width was formed. Moreover, the same material as the negative electrode diffusion layer was cut into the same size as the negative electrode diffusion layer and used for the water passage layer of the drainage mechanism. Further, an acrylic plate having a thickness of 100 μm was used as a seal plate. Then, the water passage layer, the gas seal and the seal plate were arranged as shown in FIG. 11B to produce a drainage mechanism.

  As the gas-liquid separation tube, two porous tubes made of polytetrafluoroethylene having an inner diameter of 3 mm were used.

  The 12 MEAs are stacked while the separator is interposed between the MEAs so that the oxygen flow path forming surface side is on the positive electrode diffusion layer side, and a drainage mechanism is stacked above the uppermost MEA. The gas-liquid separation tube is connected to the fuel supply port and one side of the water passage layer, and the other gas-liquid separation tube is connected to the fuel discharge port and the other side of the water passage layer. The fuel cell having the structure shown in FIG. 1 was manufactured by sandwiching the upper and lower sides with two end plates (aluminum, size: 38 mm × 90 mm) and fixing them with bolts and nuts.

(Comparative Example 1)
A fuel cell was produced in the same manner as in Example 1 except that the two gas-liquid separation tubes and the seal plate on the side surface of the water passage layer were removed.

(Comparative Example 2)
A fuel cell was produced in the same manner as in Example 1 except that the two gas-liquid separation tubes and the drainage mechanism were removed.

  The fuel cells of Example 1, Comparative Example 1 and Comparative Example 2 were supplied with hydrogen humidified at 90 ° C. and relative humidity of 100% into the gas-liquid separation tube from the fuel supply port, and at room temperature while changing the direction of the fuel cell. A constant voltage (7.0 V) operation was performed, and the power generation state in each direction was confirmed. At this time, air was supplied to the positive electrode using a blower.

  Specifically, the above operation is performed by changing the direction of the fuel cell so that the upper surface, the lower surface, and the four side surfaces (6 surfaces in total) of the fuel cell shown in FIG. The power generation status on each surface when the surface was operated as a stationary surface was inspected. Table 1 shows the number of fuel cells on which stable power generation was possible.

  From Table 1, in the fuel cell of Example 1, stable power generation was possible on all six surfaces. This is because the infiltrated water condensed in the fuel cell is guided to the drainage mechanism by the gas-liquid separation tube and is effectively discharged to the outside, and the fuel is discharged from the gas-liquid separation tube and is evenly guided to each MEA. It seems that it was because of

  On the other hand, in the fuel cell of Comparative Example 1, stable power generation was possible only when the drainage mechanism was placed at the bottom. This seems to be because the infiltration water accumulated in the lower part due to gravity could be removed by the drainage mechanism by making the drainage mechanism at the bottom, but the infiltration water could not be effectively removed in other directions.

  Furthermore, in Comparative Example 2, there was no surface capable of stable power generation. This is probably because the intrusion water cannot be effectively removed on any surface, and the output of the MEA located at the bottom is drastically reduced due to flooding due to the intrusion water accumulated by gravity.

  ADVANTAGE OF THE INVENTION According to this invention, the flooding by the water | moisture content permeated into the inside of a fuel cell can be suppressed, and the fuel cell which can produce electric power continuously and stably even if it puts a fuel cell in all directions can be provided. In the fuel cell of the present invention, the fuel cell itself and the fuel cell power generation system can be easily downsized by adopting the above-described preferred configuration. Therefore, the fuel cell of the present invention can be preferably used in various applications where a conventional fuel cell is used, such as a power supply for a high-performance portable electronic device such as a cordless device such as a personal computer or a mobile phone.

DESCRIPTION OF SYMBOLS 10 Separator 11 Fuel supply manifold 12 Fuel discharge manifold 13 Oxygen flow path 20 Electrode / electrolyte integrated material (MEA)
60 Drainage mechanism 60a Water passage layer 60b Gas seal 60c Seal plate 85, 95 Gas-liquid separation tube 100 Fuel cell

Claims (9)

An electrode / electrolyte integrated product having a positive electrode having a positive electrode catalyst layer for reducing oxygen, a negative electrode having a negative electrode catalyst layer for oxidizing fuel, and a solid polymer electrolyte membrane disposed between the positive electrode and the negative electrode , A fuel cell comprising a plurality of stacked layers via separators,
Among the plurality of stacked electrode / electrolyte integrated products, on the outer surface side of the electrode / electrolyte integrated product located at one end, a drainage mechanism having the same area in plan view as the separator is provided,
Of the plurality of stacked electrode / electrolyte integrated products, a fuel supply port and a fuel discharge port are provided on the outer surface side of the electrode / electrolyte integrated product located at the other end,
The fuel cell, wherein the drainage mechanism, the fuel supply port, and the fuel discharge port are connected by a gas-liquid separation tube, respectively. The electrode / electrolyte integrated product and the shape of the drainage mechanism are quadrangular in plan view,
The separator has a quadrangular shape in plan view and is composed of a single sheet,
Each of the electrode / electrolyte integrated body, the separator, and the drainage mechanism has a fuel supply manifold in the vicinity of one of the four sides forming a quadrangle, and a fuel in the vicinity of the other side facing the one side. A discharge manifold is formed,
The gas-liquid separation tubes are respectively disposed inside the fuel supply manifold and the fuel discharge manifold,
On one surface of the separator, a plurality of oxygen flow paths that linearly connect two sides other than the two opposite sides on which the fuel supply manifold and the fuel discharge manifold are formed are formed in parallel or substantially parallel to each other. And the other surface of the separator is planar,
The separator has a surface having the oxygen channel in contact with the positive electrode of the electrode / electrolyte integrated product, and the other planar surface is adjacent to the electrode / electrolyte integrated product via the separator. The fuel cell according to claim 1, which is in contact with the negative electrode.   The fuel cell according to claim 1, wherein the negative electrode of the electrode / electrolyte integrated product has a negative electrode diffusion layer, and the negative electrode diffusion layer is in contact with the separator. The negative electrode diffusion layer is quadrangular in plan view, and a negative electrode gas seal for suppressing outflow of fuel gas is disposed outside the outer periphery of the negative electrode diffusion layer,
A fuel supply manifold is formed by one of the four sides constituting the quadrangle of the negative electrode diffusion layer and the negative electrode gas seal, and one side facing the one side of the negative electrode diffusion layer and the negative electrode gas The fuel cell according to claim 3, wherein a fuel discharge manifold is formed by the seal. The drainage mechanism is quadrilateral in plan view and has a water passage layer having the same structure as the negative electrode diffusion layer of the electrode / electrolyte integrated body, and suppresses the outflow of fuel gas disposed on the outer periphery of the water passage layer. And a gas seal for
A fuel supply manifold is formed by one of four sides constituting the quadrangle of the water passage layer and the gas seal, and one side of the water passage layer facing the one side and the gas seal The fuel discharge manifold is formed with
A seal plate for suppressing the outflow of water is disposed on each side surface of the water passage layer on the fuel supply manifold side and the fuel discharge manifold side, and the gas-liquid separation tube is disposed on the seal plate. The fuel cell according to claim 4, wherein an opening for connecting to the water passage layer is provided.   The positive electrode of the electrode / electrolyte integrated product has a positive electrode diffusion layer, and the positive electrode diffusion layer is disposed at a location covering the entire surface of the oxygen channel of the separator. The fuel cell according to item. The positive electrode diffusion layer is quadrangular in plan view, and a positive electrode gas seal for suppressing outflow of fuel gas outside the two sides of the positive electrode diffusion layer that are parallel or substantially parallel to the oxygen flow path of the separator. Is placed,
The fuel cell according to claim 6, wherein a fuel supply manifold and a fuel discharge manifold are formed in the positive electrode gas seal.   The fuel cell according to claim 1, wherein an oxygen flow path of the separator also serves as a cooling medium flow path.   The fuel cell according to any one of claims 1 to 8, wherein the positive electrode catalyst layer, the negative electrode catalyst layer, and the solid polymer electrolyte membrane have the same shape in plan view.

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