JP2007066723A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell in which a current can be taken out efficiently from respective hollow type cells, and of which power generation efficiency can be enhanced in the fuel cell connecting two or more modules in series wherein the plurality of hollow type cells are connected in parallel. <P>SOLUTION: This is the fuel cell in which the two or more modules are connected in series wherein the two or more hollow type cells are connected in parallel. The respective modules are provided with an anode side module connecting part for collecting the current by connecting it to anode side current collecting materials of the respective hollow type cells or by connecting it to connecting networks in which the anode side current collecting materials of the respective hollow type cells are mutually connected, and provided with a cathode side module connecting part for similarly collecting the current. These mutually neighboring modules are connected in series, and the current collecting materials or the connecting networks mutually connecting the materials, and the module connecting part are connected via two or more current extracting parts in which connecting positions against the current collecting materials or the connecting networks are dispersedly arranged. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell in which two or more modules in which two or more hollow cells having a hollow electrolyte membrane are connected in parallel are connected in series.

  A fuel cell directly converts chemical energy into electrical energy by supplying fuel and an oxidant to two electrically connected electrodes and causing the fuel to be oxidized electrochemically. Unlike thermal power generation, fuel cells are not subject to the Carnot cycle, and thus exhibit high energy conversion efficiency. Solid polymer electrolyte fuel cells using a solid polymer electrolyte as an electrolyte have advantages such as easy miniaturization and operation at a low temperature. Has been.

In the solid polymer electrolyte fuel cell, when hydrogen is used as the fuel, the reaction of the formula (1) proceeds at the anode.
H ₂ → 2H ⁺ + 2e ⁻ (1)
The electrons generated by the equation (1) reach the cathode after working with an external load via an external circuit. Then, the proton generated in the formula (1) moves by electroosmosis from the anode side to the cathode side in the solid polymer electrolyte membrane in a state of being hydrated with water.

Further, when oxygen is used as the oxidizing agent, the reaction of the formula (2) proceeds at the cathode.
2H ⁺ + (1/2) O ₂ + 2e ⁻ → H ₂ O (2)
The water produced at the cathode mainly passes through the gas diffusion layer and is discharged to the outside.
As described above, the fuel cell is a clean power generation device that has no emissions other than water.

Conventionally, as a solid polymer electrolyte fuel cell, a catalyst layer serving as an anode and a cathode is provided on one surface of a planar solid polymer electrolyte membrane, and the obtained planar membrane / electrode assembly is provided. A flat unit cell has been developed in which gas diffusion layers are further provided on both sides of the substrate and sandwiched between planar separators. A plurality of such flat single cells are stacked and used as a fuel cell stack.
In order to improve the output density of the solid polymer electrolyte fuel cell, a proton conductive polymer membrane having a very thin film thickness is used as the solid polymer electrolyte membrane. This film thickness is already 100 μm or less, and even if a thinner electrolyte membrane is used to further improve the power density, the thickness of the single cell cannot be dramatically reduced from the present one. Similarly, the catalyst layer, the gas diffusion layer, the separator, and the like have been made thinner, but there is a limit to improving the output density per unit volume even by making all these members thinner. Therefore, it is expected that it will not be possible to meet the demand for miniaturization in the future.

Moreover, the sheet-like carbon material excellent in corrosivity is normally used for the said separator. In the separator, the carbon material itself is expensive, and a gas flow channel groove for uniformly distributing the fuel gas and the oxidant gas over the entire surface of the planar membrane / electrode assembly is formed by fine processing. Therefore, it has become very expensive. As a result, the manufacturing cost of the fuel cell was pushed up.
In addition to the above problems, for flat single cells, the periphery of single cells stacked in multiple layers should be securely sealed so that fuel gas and oxidant gas do not leak from the gas flow path. However, there are a number of problems such as technical difficulties, and power generation efficiency may be reduced due to deflection or deformation of the planar membrane / electrode assembly.

In recent years, a solid polymer electrolyte fuel cell has been developed in which a hollow cell in which an electrode is provided on each of an inner surface side and an outer surface side of a hollow electrolyte membrane is used as a basic power generation unit (for example, Patent Document 1). .
Since the fuel cell having such a hollow cell has a gas flow path inside the hollow cell, a member corresponding to a separator used in a flat type is not necessary. Since different types of gas are supplied to the inner surface and the outer surface for power generation, it is not necessary to form a gas flow path. Therefore, cost reduction is expected in the manufacture. Further, since the cell has a three-dimensional shape, the specific surface area with respect to the volume can be increased as compared with the flat single cell, and the power generation output density per volume can be expected to be improved.

JP-T-2004-505417

In a fuel cell having hollow cells, usually, a plurality of hollow cells are connected in parallel in order to obtain a large voltage. In order to obtain a large current, a plurality of hollow cell groups (modules) in which hollow cells are connected in parallel are further connected in series.
The hollow cell has current collectors (anode-side current collector and cathode-side current collector) connected to electrodes provided on the inner surface and the outer surface of the hollow electrolyte membrane, respectively, and the current of each cell is taken out therefrom. When connecting multiple hollow cells in parallel, connect them to the anode-side current collector of each cell and aggregate the current of the cells, and connect to the cathode-side current collector of each cell. And a cathode-side module connecting portion that collects currents of a plurality of cells. These module connection portions normally function as connection portions (terminals) when a plurality of modules are connected in series.

  A conventional fuel cell having a hollow cell has an anode-side module connection portion on one end side of a hollow cell group including a plurality of hollow-type cells connected in parallel and a cathode-side module connection on the other end side. It is common to have a structure in which adjacent modules are connected in series by these module connection portions (see Patent Document 1).

  Thus, when an anode side module connection part is provided at one end of the hollow cell and a cathode side module connection part is provided at the other end, the electrode region located on the end side opposite to the one end provided with the module connection part However, since the path to the module connection part is long, it is difficult to take out the current, and the current collection efficiency is lowered.

At this time, the current collection efficiency decreases as the length of the hollow cell in the longitudinal direction increases. This is because when the hollow cell becomes longer, the distance between the electrode region located on the side opposite to the end where the module connection portion is provided and the module connection portion increases, and the current collection path becomes longer.
Further, when the length of the hollow cell is increased, the electrode area of each hollow cell is enlarged and the power generation amount of one cell is increased, so that the contact area between the module connection portion and each hollow cell is increased. It is hoped that.

  The present invention has been accomplished in view of the above circumstances, and in a fuel cell in which two or more modules in which a plurality of hollow cells are connected in parallel are connected in series, an electric current is efficiently extracted from each hollow cell. The purpose is to increase power generation efficiency.

  The fuel cell of the present invention has a hollow electrolyte membrane, a pair of electrodes provided on the inner and outer surfaces of the hollow electrolyte membrane, and a current collector connected to the pair of electrodes, respectively, and at least one end portion is A fuel cell in which two or more open hollow cells connected in parallel are connected in series, and each module is connected to the anode current collector of each hollow cell or each hollow cell Connected to a connection network in which anode-side current collectors of each type cell are connected to each other and connected to the anode-side module collector for collecting current, and connected to the cathode-side current collector of each hollow cell, or the cathode side of each hollow cell A cathode-side module connection part that collects current by connecting to a connection network in which current collectors are connected to each other is provided, and between adjacent modules, the anode-side module connection part of one module Are connected in series with the cathode side module connecting portion of the other module, and in at least one of the modules, at least one of the current collectors of the anode side and the cathode side of each hollow cell, or they are connected to each other The connection network and the module connection portion are connected via two or more current extraction portions in which connection positions with respect to the current collector or the connection network are dispersedly arranged.

  The fuel cell according to the present invention provides a module from a current collector by taking out current from each of the current collectors or connection networks on the anode side and / or cathode side from the current draw parts at two or more locations and consolidating them in the module connection part. It is possible to shorten the current collecting path leading to the connecting portion and suppress the decrease in the current collecting efficiency due to the resistance caused by the current collecting material or the like.

  From the viewpoint of improving the current collection efficiency, in all the modules, at least one of the current collectors on the anode side and the cathode side of each hollow cell, or the connection network connecting them together and the module connection portions, are distributed. It is preferable that they are connected via each of the current drawing portions.

  In general, it is preferable to disperse and arrange the connection positions of the respective current drawing portions arranged in a distributed manner with respect to the module connecting portion at two or more locations on the module connecting portion.

The structure of the said current drawing part is not specifically limited, For example, the said current drawing part and the said module connection part may have an integral structure. Specifically, there may be mentioned a form in which the module connecting portion has a structure in which each of the current drawing portions and a communication portion that electrically communicates each of the current drawing portions are integrally formed.
At this time, the modules that are adjacent and connected in series are such that the communication part of the anode-side module connection part of one module and the communication part of the cathode-side module connection part of the other module face each other. They are in contact and connected in series, and the contact surfaces of the two communication parts are perpendicular to the direction in which the current concentrated in the communication part flows to the communication part of the adjacent module connected to the communication part. It is preferable. Specifically, the module connecting portion is formed by forming a plate-shaped conductive material into a U-shape so that the two plate-shaped current extraction portions are disposed at both ends of the plate-shaped communication portion. And the communication portion is disposed so as to be parallel to the longitudinal direction of the hollow cell, and the current extraction portion approaches the current collector of the hollow cell from the side surface direction of the hollow cell. Are preferably connected.

  The structure of the anode-side current collector and the cathode-side current collector and the arrangement of the current extraction portion with respect to each current collector are not particularly limited. For example, among the anode-side current collector and the cathode-side current collector, the hollow electrolyte membrane The current collector connected to the electrode provided on the outer surface of the electrode comprises a rod-shaped current collector arranged in parallel with the hollow cell, the plurality of hollow cells, and the rod-shaped current collector provided in the plurality of hollow cells. In the case of the braided net current collector, there can be mentioned a mode in which two or more current extraction portions are dispersedly arranged on the rod-shaped current collector of each hollow cell.

  At this time, the farthest position among the respective current extraction portions dispersedly arranged on the rod-shaped current collector of each hollow cell is a half of the total length of the rod-shaped current collector in the longitudinal direction of the hollow cell. It can be arranged with one or more intervals. Further, the most distant positional relationships among the current drawing portions may be provided at both ends of the rod-shaped current collector in the longitudinal direction of the hollow cell.

On the other hand, among the anode side current collector and the cathode side current collector, the current collector connected to the electrode provided on the outer surface of the hollow electrolyte membrane is a connection network made of a net-like current collector knitting the plurality of hollow cells. In some cases, two or more of the current extraction units can be dispersedly arranged on a connection network made of the mesh current collector.
The connection position of each of the current drawn portions arranged in a distributed manner with respect to the current collector or the connection network is determined by each of the current collecting material or each region of the connection network from which the current is drawn by each current draw portion. It is preferable that the generated current amount is a position where the generated current amount is equal to or less than the current capacity when the generated current amount in the region is compared with the current capacity of the current collector or the connection network. Distributing the current extraction parts in this way makes it possible to use a hollow cell having a large amount of generated current (for example, a hollow cell having a long cell length) or a current capacity of the hollow cell to be collected. Even when a small current collector or connection network is used, current can be collected efficiently.

According to the present invention, in a fuel cell including a module in which a plurality of hollow cells are connected in parallel, a current collector for each hollow cell in the module or a connection network in which current collectors for each hollow cell are connected to each other, and By connecting the current collector or the module connection part that collects the current of the connection network via two or more current extraction parts in which the connection positions with respect to the current collector are dispersedly arranged, the current is efficiently supplied from each hollow cell. Therefore, it is possible to provide a fuel cell with excellent current collection efficiency and high power generation efficiency.
In addition, by providing two or more current extraction portions distributed in this way, enabling efficient current extraction, the cell length of the hollow cell is increased (specifically, for example, 600 mm, for example). This is possible. At this time, by using a hollow cell having a long cell length, the power generation current of each hollow cell increases, but since it has a plurality of current extraction parts, each current collector or each connection network and the entire current extraction part It is easy to ensure the contact area of the current, and the cross-sectional area of the entire current extraction part (the cross-sectional area perpendicular to the direction of current flow to the part that becomes the electrical connection part with the adjacent module) is sufficient for the generated current It can be ensured that it can be washed away.

  The fuel cell of the present invention has a hollow electrolyte membrane, a pair of electrodes provided on the inner and outer surfaces of the hollow electrolyte membrane, and a current collector connected to the pair of electrodes, respectively, and at least one end portion is A fuel cell in which two or more open hollow cells connected in parallel are connected in series, and each module is connected to the anode current collector of each hollow cell or each hollow cell Connected to a connection network in which anode-side current collectors of each type cell are connected to each other and connected to the anode-side module collector for collecting current, and connected to the cathode-side current collector of each hollow cell, or the cathode side of each hollow cell A cathode-side module connection part that collects current by connecting to a connection network in which current collectors are connected to each other is provided, and between adjacent modules, the anode-side module connection part of one module Are connected in series with the cathode side module connecting portion of the other module, and in at least one of the modules, at least one of the current collectors of the anode side and the cathode side of each hollow cell, or they are connected to each other The connection network and the module connection portion are connected via two or more current extraction portions in which connection positions with respect to the current collector or the connection network are dispersedly arranged.

  Hereinafter, an embodiment of the fuel cell of the present invention will be described with reference to FIGS. In the following embodiment, the description will focus on a polymer electrolyte fuel cell using hydrogen gas as the fuel and air (oxygen) as the oxidant, but the present invention is not limited to the following embodiment. Absent. 1 to 11 are partially omitted for convenience.

(Hollow cell)
FIG. 1 is a schematic view showing an embodiment of hollow cells that are connected in parallel to form a module in the fuel cell of the present invention, and FIG. 2 is a cross-sectional view of the hollow cell of FIG. 1 and 2, a hollow cell 6 includes a tubular solid polymer electrolyte membrane (perfluorocarbon sulfonic acid resin membrane) 1 and an anode (in this embodiment, a fuel provided on the inner surface side of the solid polymer electrolyte membrane 1). Electrode) 2 and a cathode (air electrode in this embodiment) 3 provided on the outer surface side. Further, a columnar current collector is disposed as the anode-side current collector 4 on the surface of the anode 2, and a net-like (net-shaped) current collector 5 a made of metal wire and a rod-shaped current collector are disposed as the cathode current collector 5 on the surface of the cathode 3. The electric material 5b is arranged.
On the hollow inner surface of the hollow cell having such a structure (substantially, the portion exposed to the inner surface side gas flow path formed by the groove 4a provided on the outer surface of the anode current collector 4), hydrogen gas on the outer surface By circulating air, fuel or an oxidant is supplied to the anode and cathode to generate electricity.

  The hollow cell 6 shown in FIG. 1 has hollow portions open at both ends, and the fuel gas flows from one end into the hollow and flows out from the other end. In the hollow cell 6, if the reaction gas can be sufficiently supplied to the inner surface side of the hollow electrolyte membrane, only one end of the hollow portion may be opened and the other end may be sealed. In particular, as in the present embodiment, when providing a fuel electrode using hydrogen as a fuel as the inner surface side electrode, hydrogen gas containing almost no non-reactive component can be supplied into the hollow of the hollow cell as a fuel gas, In addition, since the diffusibility of hydrogen molecules is high, the reaction gas supplied into the hollow can be consumed, so that the reaction gas can be sufficiently supplied even in the hollow portion with one end sealed. . Examples of the method of sealing one end of the hollow cell include a method of injecting resin or the like into the hollow one end, but is not particularly limited.

  In FIG. 1, the hollow cell 6 has a tubular electrolyte membrane, but the hollow electrolyte membrane in the present invention is not limited to a tubular shape, has a hollow portion, and fuel and an oxidant flow into the hollow portion. By doing so, it is only necessary that the reaction component necessary for the electrochemical reaction can be supplied to the electrode provided in the hollow interior.

The inner diameter, outer diameter, length and the like of the tubular solid polymer electrolyte membrane 1 are not particularly limited, but the outer diameter of the tubular electrolyte membrane is preferably 0.01 to 10 mm, 0.1 More preferably, it is-1 mm, and it is especially preferable that it is 0.1-0.5 mm. At present, it is difficult to manufacture a tubular electrolyte membrane having an outer diameter of less than 0.01 mm due to technical problems. On the other hand, when the outer diameter exceeds 10 mm, the surface area relative to the occupied volume is not so large. The output per unit volume of the obtained hollow cell may not be sufficiently obtained.
The perfluorocarbon sulfonic acid resin membrane is preferably thin from the viewpoint of improving proton conductivity, but if it is too thin, the function of isolating gas is lowered and the permeation amount of aprotic hydrogen is increased. However, compared to conventional fuel cells in which flat single cells for fuel cells are stacked, a fuel cell manufactured by collecting a large number of cells having a hollow shape can take a large electrode area, so a slightly thicker membrane is formed. Even when used, a sufficient output can be obtained. From this viewpoint, the thickness of the perfluorocarbon sulfonic acid resin film is 10 to 100 μm, more preferably 50 to 60 μm, and still more preferably 50 to 55 μm.
Moreover, from the preferable range of said outer diameter and film thickness, the preferable range of an internal diameter is 0.01-10 mm, More preferably, it is 0.1-1 mm, More preferably, it is 0.1-0.5 mm. is there.

  Since the fuel cell of the present invention has a hollow cell, the electrode area per unit volume can be made larger than that of a fuel cell having a flat cell. Therefore, as the solid polymer electrolyte membrane, perfluorocarbon sulfonic acid is used. Even when an electrolyte membrane that does not have a proton conductivity as high as that of a resin membrane is used, a fuel cell having a high output density per unit volume can be obtained. As the solid polymer electrolyte membrane, perfluorocarbon sulfonic acid resin and materials used for the electrolyte membrane of solid polymer fuel cells can be used. For example, fluorine other than perfluorocarbon sulfonic acid resin can be used. One kind of proton exchange groups such as at least sulfonic acid groups, phosphonic acid groups, and phosphoric acid groups, based on hydrocarbons such as polyolefins such as polystyrene ion exchange resins and polystyrene cation exchange membranes having sulfonic acid groups A complex of a basic polymer and a strong acid, which is disclosed in Japanese Patent Application Laid-Open No. 11-503262, etc., in which a basic polymer such as polybenzimidazole, polypyrimidine, and polybenzoxazole is doped with a strong acid And polymer electrolytes such as solid polymer electrolytes. A solid polymer electrolyte membrane using such an electrolyte should be reinforced with a perfluorocarbon polymer in the form of a fibril, a fabric, a non-fabric, or a porous sheet, or the membrane surface can be coated with an inorganic oxide or metal. It can also be reinforced. In addition, examples of the perfluorocarbon sulfonic acid resin membrane include commercially available products such as Nafion manufactured by DuPont and Flemion manufactured by Asahi Glass.

In the present embodiment, a perfluorocarbon sulfonic acid resin membrane, which is a kind of proton conductive membrane and one of solid polymer electrolyte membranes, is described as an electrolyte membrane, but it is used in the fuel cell of the present invention. The electrolyte membrane to be used is not particularly limited, and may be proton-conductive or other ion-conductive such as hydroxide ion or oxide ion (O ²⁻ ). The proton conductive electrolyte membrane is not limited to the solid polymer electrolyte membrane as described above, but a porous electrolyte plate impregnated with an aqueous phosphoric acid solution, a proton conductor made of porous glass, or a hydrogel Phosphated phosphate glass, organic-inorganic hybrid proton conductive membrane having proton conductive functional groups introduced into the surface and pores of nanoporous glass, inorganic metal fiber reinforced electrolyte polymer, etc. can be used. . Depending on the configuration of the fuel cell, for example, when the present invention is applied to a solid oxide fuel cell or to a solid polymer fuel cell using hydroxide ions as charge carriers, oxygen ions or It may be a solid electrolyte membrane that conducts ions serving as other charge carriers such as hydroxide ions.

The electrodes 2 and 3 provided on the inner and outer surfaces of the electrolyte membrane (perfluorocarbon sulfonic acid resin membrane) 1 can be formed using an electrode material such as that used in a polymer electrolyte fuel cell. Usually, an electrode configured by laminating a catalyst layer and a gas diffusion layer in order from the electrolyte membrane side is used.
The catalyst layer includes catalyst particles, and may further include a proton conductive material for increasing the utilization efficiency of the catalyst particles. As the proton conductive material, those used as the material for the electrolyte membrane can be used. As the catalyst particles, catalyst particles in which a catalyst component is supported on a conductive material such as a carbon material such as carbonaceous particles or carbonaceous fibers are preferably used. Since the fuel cell of the present invention has a hollow cell, the electrode area per unit volume can be made larger than that of a fuel cell having a flat cell. Therefore, a catalyst component that is not as catalytic as platinum is used. However, a fuel cell having a high output density per unit volume can be obtained. The catalyst component is not particularly limited as long as it has a catalytic action for hydrogen oxidation reaction at the anode and oxygen reduction reaction at the cathode. For example, platinum (Pt), ruthenium (Ru), iridium (Ir) , Rhodium (Rh), palladium (Pd), osmium (Os), tungsten (W), lead (Pb), iron (Fe), chromium (Cr), cobalt (Co), nickel (Ni), manganese (Mn) , Vanadium (V), molybdenum (Mo), gallium (Ga), aluminum (Al) and other metals, or alloys thereof. Pt and an alloy made of Pt and another metal such as Ru are preferable.

As the gas diffusion layer, a porous conductive material mainly composed of a carbon material such as carbonaceous particles and / or carbonaceous fibers can be used. The sizes of the carbonaceous particles and the carbonaceous fibers may be appropriately selected in consideration of the dispersibility in the solution when the gas diffusion layer is produced, the drainage property of the obtained gas diffusion layer, and the like. The gas diffusion layer is, for example, polytetrafluoroethylene, polyvinylidene fluoride (PVDF), polytetrafluoroethylene, perfluorocarbon alkoxyalkane, ethylene-tetrafluoroethylene polymer, or these from the point of improving the drainage of moisture such as generated water It is preferable to perform water-repellent processing by impregnating a mixture of the above or the like or forming a water-repellent layer using these substances.
In addition, the structure of each electrode provided in the inner surface and outer surface of a hollow electrolyte membrane, the material used for an electrode, etc. may be the same, and may differ.

The method of providing a pair of electrodes on the inner and outer surfaces of the tubular electrolyte membrane is not particularly limited. For example, first, a tubular electrolyte membrane is prepared. The method for preparing the tubular electrolyte membrane is not particularly limited, and a commercially available electrolyte membrane formed in a tube shape can also be used. Then, a solution containing electrolyte and catalyst particles is applied and dried on the inner and outer surfaces of the tubular electrolyte membrane to form a catalyst layer, and carbonaceous particles and / or carbonaceous fibers are contained on the two catalyst layers. The method of apply | coating and drying a solution and forming a gas diffusion layer is mentioned. At this time, the catalyst layer and the gas diffusion layer are formed so that a hollow portion exists on the inner surface of the gas diffusion layer formed on the inner surface side of the electrolyte membrane.
Alternatively, first, a gas material containing a carbon material such as carbonaceous particles and / or carbonaceous fibers and formed into a tube shape (tubular carbonaceous material) is used as the gas diffusion layer of the inner surface side electrode (anode), and the gas diffusion is performed. Applying and drying a solution containing electrolyte and catalyst particles on the outer surface of the layer to form a catalyst layer of the inner surface side electrode to produce the inner surface side electrode, and then applying a solution containing the electrolyte to the outer surface of the catalyst layer. The electrode layer is dried to form a catalyst layer of the outer electrode (cathode) on the outer surface of the electrolyte membrane layer, and a solution containing a carbon material is applied to the outer surface of the catalyst layer and dried to dry the gas of the outer electrode. A method for forming a diffusion layer is also included. The tubular carbonaceous material can be obtained, for example, by dispersing a carbon material such as carbonaceous particles and an epoxy and / or phenolic resin in a solvent to form a tubular shape, thermosetting, and firing.

In addition, the solvent used when forming the electrolyte membrane, the catalyst layer, and the gas diffusion layer may be appropriately selected according to the material to be dispersed and / or dissolved, and the coating method when forming each layer is also as follows. It can be appropriately selected from various methods such as spraying and screen printing.
The hollow cell used in the fuel cell of the present invention is not limited to the configuration exemplified above, and layers other than the catalyst layer and the gas diffusion layer may be provided for the purpose of enhancing the function of the hollow cell. In this embodiment, the anode is provided inside the hollow electrolyte membrane and the cathode is provided outside, but the cathode may be provided inside and the anode may be provided outside.

  An anode side current collector (in this embodiment, an internal current collector disposed on the inner surface side electrode surface) 4 is a columnar current collector having an outer diameter in contact with the inner peripheral surface of the hollow cell. A groove 4a extending in the axial direction (longitudinal direction) of the mold cell is formed. A gap between the groove and the inner surface side electrode 2 becomes a hollow gas passage for supplying hydrogen gas. As the groove 4a, at least one groove extending in the axial direction (longitudinal direction) of the hollow cell is required, and grooves having various patterns or directions are formed on the outer peripheral surface of the hollow cell as necessary. The

  A net-like current collector 5a, which is a part of the cathode-side current collector (in this embodiment, an external current collector disposed on the surface of the outer electrode) 5 is an array of hollow cells and rod-shaped current collectors 5b arranged in parallel. It can be manufactured by braiding a metal wire so as to cover the outer peripheral surfaces of both (see FIG. 7). The rod-shaped current collector 5b may have a tube shape having a hollow portion 5c through which fluid and gas can flow, and a coolant for cooling the cells may be circulated in the hollow portion 5c of the rod-shaped current collector (see FIG. 1). ).

In FIG. 7, a net-like current collector 5a made of a metal wire is formed so that a plurality of hollow cells 6 and a rod-like current collector 5b of each hollow cell are integrated, and the cathode (outside electrode) of each hollow cell. ) And each rod-shaped current collector 5b, a metal wire is knitted so that the mesh-shaped current collector 5a is shared by a plurality of hollow cells. At this time, the cathode side current collectors (5a, 5b) of the hollow cells form a connection network electrically connected to each other.
The form using the mesh current collector is not limited to the above case, and may be a form in which metal wires are woven so as to integrate one hollow cell and one rod current collector (without forming a connection network), Alternatively, a metal wire is knitted so that a plurality of hollow cells and a single rod current collector are integrated, and the current of the plurality of hollow cells is transferred to a single rod current collector through the metal wire of the mesh current collector. You may form the connection network formed so that it may gather.

  Further, as shown in FIG. 3, the external current collector may be only the net-shaped current collector 5a made of a metal wire without using the rod-shaped current collector 5b. At this time, a metal wire may be knitted so as to integrate a plurality of hollow cells, and each hollow cell may share this network current collector (each current collector is connected to each other).

  Examples of the metal used as the cathode side or anode side current collector include at least one metal selected from Al, Cu, Fe, Ni, Cr, Ta, Ti, Zr, Sm, In, and the like, Or their alloys such as stainless steel are preferred. Further, the surface thereof may be coated with Au, Pt, conductive resin or the like. Of these, stainless steel and titanium are preferred because of their excellent corrosion resistance. The thickness of the wire and the braid density, the thickness of the rod-shaped current collector, etc. are not particularly limited.

Here, the columnar internal current collector (anode-side current collector in this embodiment) 4 and the external current collector (a cathode current collector in this embodiment) 5 consisting of a net-like current collector 5a and a rod-like current collector 5b are mainly shown here. As described above, the current collectors 4 and 5 are not particularly limited, and the shape thereof is arbitrary as long as it is made of an electrically conductive material. The current collector may be a columnar shape, a wire shape, a rod shape, a linear shape, or a cylindrical shape. For example, a material made of a sheet material such as a spring-like metal wire, a metal foil, a metal sheet, or a carbon sheet can be applied. Also, on the anode side (hollow cell inner surface side), a connection network in which anode-side current collectors of the respective hollow cells are electrically connected to each other may be formed.
These current collectors are fixed on the electrodes with a conductive adhesive such as a carbon-based adhesive or an Ag paste as necessary.

(Module and fuel cell)
The fuel cell of the present invention is obtained by serially connecting two or more modules in which two or more hollow cells as described above are connected in parallel. Hereinafter, the module according to the present invention will be described with reference to FIGS.
FIG. 4 is a diagram showing an example of a module provided in a fuel cell to which the present invention is applied. FIG. 5 is a partially exploded view of the module of FIG. FIG. 6 is a schematic diagram in which the modules shown in FIG. 4 are connected in series. For convenience, the number of hollow cells, each gas flow path, and the like are partially omitted.

In the module 100 shown in FIGS. 4 and 5, the hollow cell 6 has the structure shown in FIGS. 1 and 2. That is, the cathode side current collector (external current collector) is composed of the rod-shaped current collector 5 b and the net-shaped current collector 5 a, and the anode side current collector (internal current collector) is composed of the columnar current collector 4. Moreover, the rod-shaped current collector 5b and the columnar current collector 4 have a current capacity capable of flowing the generated current of one hollow cell without loss.
The plurality of hollow cells 6 are knitted integrally by the mesh current collector 5a in a state in which the hollow cells 6 and the rod-shaped current collectors 5b of the hollow cells are arranged alternately and in parallel. (See FIG. 7). In the hollow cell group 7, two or more hollow cells 6 are aligned in parallel at a predetermined interval in the longitudinal direction.

  Further, the module 100 includes an anode-side module connection portion 8 that is electrically connected to the anode-side current collector 4 of each hollow cell 6 to collect current, and a rod-shaped current collector of the cathode-side current collector 5 of each hollow cell 6. A cathode-side module connection portion 9 that is electrically connected to the electric material 5b and collects current is provided, and the anode-side module connection portion 8 and the cathode-side module connection portion 9 form each hollow cell group 7 The type cells 6 are connected in parallel.

  In FIG. 4, the anode-side current collector 4 of each hollow cell 6 is exposed to the outer surface at both ends of each hollow cell 6. The anode-side current collector 4 and the anode-side module connecting portion 8 of each hollow cell 6 are arranged in contact with the exposed portions of the anode-side current collector 4 at both ends. They are connected via 8a and 8b.

The comb-shaped anode-side current extraction portions 8a and 8b have a comb-shaped structure 10 having a plurality of grooves 10a and teeth 10b, and the anode-side current collector 4 of each hollow cell 6 is inserted into each groove 10a. Thus, the anode side current collector 4 and the respective current drawing portions 8a and 8b are connected. In the comb-shaped groove 10a, a plurality of anode-side current collectors 4 can be inserted per groove, and each of the inserted anode-side current collectors 4 comes into contact with the teeth 10b, and each anode-side current collector 4 and current draw The portions 8a and 8b are provided at intervals such that they are electrically connected.
The anode-side current extraction portions 8 a and 8 b have a sufficient contact area with the anode-side current collector 4 of each hollow cell 6, and the anode-side current collector of each hollow cell 6 in the hollow cell group 7. It has a current capacity sufficient to extract current from the electric material 4. Further, the anode-side current extraction portions 8a and 8b constitute a part of the anode-side module connection portion 8, and are electrically integrated by the communication portion 8c.
In this way, the anode-side current collector 4 of each hollow cell 6 draws current from the two anode-side current extraction portions 8a and 8b that are connected in a distributed manner at both ends thereof, and each current extraction portion 8a and 8b. The current drawn from the anode-side current collector 4 of each hollow cell 6 is collected at the anode-side module connection part (communication part 8c) 8.

  When current is taken out from a plurality of points of the current collector or connection network as in the present invention, there is unevenness in power generation of each hollow cell, current collection condition at the current extraction position of the current collector or connection network, etc. For this reason, it is preferable that the modules be connected (series connection) after a plurality of current extraction units are aggregated for each module.

On the other hand, the cathode-side rod-shaped current collector 5b disposed on the outer surface of each hollow cell 6 is connected to the cathode-side module via comb-shaped current extraction portions 9a and 9b respectively disposed at both ends of each rod-shaped current collector 5b. Connected to the unit 9.
Like the anode side, the comb-shaped current extraction portions 9a and 9b have a comb structure 11 having a plurality of grooves 11a and teeth 11b, and the cathode side rod-shaped current collector 5b of each hollow cell 6 is inserted into each groove 11b. ing. In the comb-shaped groove 11a, a plurality of cathode-side bar-shaped current collectors 5b can be inserted per groove, and the inserted cathode-side bar-shaped current collectors 5b come into contact with the teeth 10b and each cathode-side bar-shaped current collector 5b And the current drawing portions 9a and 9b are provided at intervals such that they are electrically connected.
Further, the current extraction portions 9 a and 9 b have a sufficient contact area with the cathode-side rod-shaped current collector 5 b of each hollow cell 6, and the cathode-side rod-shaped collector of each hollow cell 6 of the hollow cell group 7. It has a current capacity sufficient to extract current from the electric material 5b. Moreover, the current extraction parts 9a and 9b constitute a part of the cathode side module connection part 9, and are electrically integrated by the communication part 9c.

  As described above, the cathode-side current collector 5 of each hollow cell 6 draws current from the two current draw portions 9a and 9b that are dispersed and connected to both ends of each rod-like current collector 5b, and each current draw portion The current drawn from the cathode-side current collector 5b of each hollow cell 6 by 9a and 9b is collected at the cathode-side module connection part (the communication part 9c in the present embodiment).

  And, the anode side module connection part that collects current by connecting to the anode side current collector of each hollow cell incorporated in the module, and the cathode side that collects current by connecting to the cathode side current collector of each hollow cell The module connecting portion is an electrical connecting portion with an adjacent module, and in the adjacent module, the anode side module connecting portion 8 of one module and the cathode side module connecting portion 9 of the other module are connected. As a result, adjacent modules are connected in series (see FIG. 6). At this time, the contact surface of each module connection part (communication part) which forms the serial connection between adjacent modules is arranged so as to be parallel to the longitudinal direction of the hollow cell in the module.

The fuel cell of the present invention has a great feature in that current is concentrated from the current collectors or connection networks on the anode side and / or cathode side to the module connection portion through two or more current extraction portions. is there. In each current drawing portion, connection positions with respect to each current collector or connection network are distributed.
Here, the connection positions with respect to each current collector or connection network are distributed, and the current collector on the same polarity side of each hollow cell included in the module is electrically independent for each cell. In this case, it is said that the connection points of the current extraction parts are dispersedly arranged at two or more locations on the current collector of each cell, or the current collector on the same polarity side of each hollow cell included in the module. However, when all or some of the cells are electrically connected to form one or a plurality of connection networks, the connection points of the above-described current extraction units are provided at two or more locations on each connection network. Is distributed. Even in the case where a connection network is formed, the current collecting material (this is the net current collecting material 5a in this example) for connecting each hollow cell and the current collecting material distributed to each one or a plurality of cells (this In the example, when there is the rod-shaped current collector 5b), it is preferable that the connection points of the current draw-out portions are dispersedly arranged at two or more locations on each sorted current collector.

  Each current portion lead-out portion is arranged at intervals such that the current collection path from each current collector or connection network to the module connection portion is shortened by providing two or more locations, and current can be efficiently extracted. Specifically, in the present embodiment, the most distant positional relationship among the current extraction parts distributed and arranged in the current collector such as a rod-shaped current collector or a columnar current collector is a hollow cell of the current collector. It arrange | positions with the space | interval of 1/2 or more of the full length in a longitudinal direction. Typically, the most distant positional relationships among the current extraction portions are arranged at both ends of each current collector in the longitudinal direction of the hollow cell. One or more current extraction units may be arranged between the two current extraction units that are located in the farthest position so as to equally divide or divide the two current extraction units. When three or more current extraction parts are provided in this manner, the current extraction is performed so that there is an interval within the range of ± 10% of the distance obtained by equally dividing or equally dividing the two current extraction parts in the farthest positional relationship. It is preferable to arrange the parts.

  It should be noted that in each current extraction portion, a portion perpendicular to the direction in which current flows to a portion (in this example, the communication portions 8c and 9c of the module connection portions 8 and 9) that becomes an electrical connection portion with an adjacent module. The cross-sectional area (hereinafter simply referred to as the cross-sectional area of the conductive path) is the total cross-sectional area of all the current extraction parts connected in a distributed manner to each current collector or connection network, and the current collector or connection network collects current. The power generation current of the cell can be sufficiently passed. That is, the total current capacity of all the current drawing units is equal to or greater than the amount of generated current of the current collecting material connected to these current drawing units or the cell collecting the connection network.

  As described above, the fuel cell of the present invention uses the current of the anode-side current collector (or connection network) and / or the cathode-side current collector (or connection network) of each hollow cell 6 as the current collector (connection network). Compared to the case where current is taken out from only one end of each current collector as in the conventional case, the module is taken out from the current collector at two or more locations where the connection positions to the module are distributed and collected in the module connection part. It is possible to shorten the current collecting path leading to the connecting portion and suppress the decrease in the current collecting efficiency due to the resistance caused by the current collecting material or the like.

As a result, according to the present invention, since the current collection efficiency is low in a conventional fuel cell that draws current from only one end of each current collector, the length in the longitudinal direction that could not be used is long (specifically It is possible to use a hollow cell. In addition, by increasing the length of the hollow cell in the longitudinal direction, the amount of generated current of each hollow cell increases. However, by providing two or more current extraction parts, each current collector or connection network and current extraction Since it is easy to ensure the contact area with the part, current can be efficiently taken out from each current collector or connection network. Further, by providing a plurality of current drawing portions, it is possible to ensure the total cross-sectional area of each current drawing portion so that the generated current of the cell can sufficiently flow. Therefore, a decrease in power generation efficiency due to heat generation or the like in the current extraction unit is unlikely to occur.
Also, by using a hollow cell having a long length in the longitudinal direction, it is possible to secure an electrode area even if the number of hollow cells is reduced as compared with a conventional fuel cell having a short hollow cell. As a result, it is possible to reduce the volume of the gas flow path for the inner surface through which the reaction gas to be supplied to the inner surface of each hollow cell is circulated, and the miniaturization of the fuel cell can be achieved. In addition, since the number of hollow cells is reduced, there is an advantage that the fuel cell can be easily assembled.

In the present embodiment shown in FIGS. 4 to 7, the current extraction portions (8 a, 8 b, 9 a, 9 b) are plate-shaped, and the contact area between each current extraction portion and each current collector is determined by the current extraction portion. Depends on the thickness of the plate to be formed. That is, when providing current drawing portions at two or more places on each current collector as shown in FIGS. 4 to 6, a plate-like current drawing portion having an equivalent thickness is provided only at one end (one place) of each current collecting material. Compared to the case, the contact area between each current collector and the entire current extraction portion is twice or more.
At this time, the cross-sectional area of the conductive path of the current extraction portion is simply doubled by providing the current extraction portions at two or more locations. In other words, the current capacity of the entire current extraction portion is more than double that of the case where the current extraction portion having the same thickness is provided at one place.

  Therefore, by providing two or more current extraction parts, it is possible not only to shorten the current collection path but also to greatly increase the current capacity, and to improve the current collection efficiency from each current collector of each current extraction part. Can do. As a result, it is possible to efficiently extract current from a hollow cell having a length twice or more.

  Furthermore, even if the thickness of each plate-like current extraction portion is reduced, it is possible to sufficiently ensure the contact area and current capacity with each current collector. Thus, by making it possible to reduce the thickness of the plate-like current extraction portion, for example, a plate-like conductive material is formed into a U-shape by bending, and this is shown in FIGS. Thus, it can be used as a module connection portion having a communication portion and two current extraction portions connected to both ends thereof.

  At this time, the communication portions 8c and 9c of the module connection portions 8 and 9 have a flat plate shape having a wide flat surface. Furthermore, these communication parts 8c and 9c are arrange | positioned so that it may oppose in the state pinched | interposed between two modules. And in the communication parts 8c and 9c of each module connection part 8 and 9, adjacent modules contact | abut and surface-contact, and are connected in series. That is, as shown in FIG. 6, the communicating portion 8c of the anode side module connecting portion 8 of the module 100a and the communicating portion 9c of the cathode side module connecting portion 9 of the adjacent module 100b come into contact with each other, and the cathode side module connecting portion of the module 100a. 9 communication portions 9c and the communication portion 8c of the anode side module connection portion 8 of the adjacent module 100c abut, and these three modules 100b, 100a, 100c are connected in series.

  Thus, when the part which contact | abuts with the adjacent module and forms a serial connection (in the above-mentioned example) (communication part) is flat form which forms the whole contact surface with the said adjacent module, adjacent modules mutually Since the contact area is large, the conduction between adjacent modules is excellent.

  Furthermore, in the U-shaped module connection part of FIGS. 4-6, each electric current extraction part 8a, 8b (9a, 9b) approaches the current collection material of the said hollow type cell from the side surface direction of the hollow type cell 6, and connects. Since the angle of the communication portion 8c (9c) is changed by 90 degrees with respect to the current drawing portions 8a and 8b (9a and 9b), the communication portion 8c (9c) is arranged in the longitudinal direction of the hollow cell 6. It is parallel to it. At this time, the direction in which the plane of the communication portion expands is perpendicular to the direction of the conductive path of the communication portion (the direction in which current flows to the module connection portion of the adjacent module). The cross-sectional area of the road. That is, the communication part forming the series connection with the adjacent module has a large cross-sectional area of the conductive path, and a sufficient current capacity is ensured. Moreover, since the resistance at the communication portion is reduced by forming the communication portion with a thin plate-like conductive material, the modules connected in series at the communication portion are excellent in conductivity and excellent in current collection efficiency. Yes.

Specifically, the 150 mm (cell longitudinal length of the effective power generation electrode) generating the effective length, 1 cm ² per 0 power generation performance of the tubular cells of the outer diameter of 1 mm (power generation effective area 4.71cm ^2). Assuming 6V and 0.64A, the total generated current of a module on which 125 tube-type cells are connected in parallel is 125 × 0.64A × 4.71 cm ² = about 377A. At this time, when a copper flat plate having a thickness of 1 mm and a width of 50 mm is bent to form a U-shaped module connection portion as shown in FIG. The cross-sectional area of the conductive path in the portion that becomes the electrical connection portion between the ^two is 50 mm × 150 mm = 7500 mm ² . Copper can be calculated as generally allowing a current of 5 A per mm ² to flow.

That is, when the adjacent modules to each other are completely surface-contact with the communicating portion, the communicating portion, a current can flow to the computational ^{7500mm 2 × 5A / mm 2 =} 37.5kA. Therefore, at this time, a sufficient current capacity is secured between the communication portions forming the electrical connection between the modules.
Further, in this example, the total cross-sectional area of the conductive paths in the two current extraction portions is 1 mm × 50 mm × 2 = 100 mm ² , and a current of up to 500 A can flow through these two current extraction portions, so that the total current A sufficient current capacity is secured in the lead-out portion.
The generated power per module on which 125 hollow cells having the above-described power generation performance (0.6 V per cm ² , 0.64 A) are mounted is 0.6 V × 377 A = about 225 W. At this time, assuming that the maximum voltage of the module is 1V, a fuel cell in which 400 such modules are connected in series exhibits power generation performance of maximum 400V (1V × 400) and 90 kW (225W × 400).

  Here, as shown in FIG. 13, when the connecting portion that aggregates a plurality of current drawing portions and the connecting portion that gathers the current drawing portions of the counter electrodes of the adjacent modules are connected at the module connecting portion, FIGS. Unlike the configuration of 6, the direction of the current flowing in the connecting portion and the module connecting portion (indicated by an arrow) and the direction of the connecting portion and the module connecting portion are the same, so the connecting portion and the module connecting portion are the total current amount of each module. It is necessary to increase the plate thickness of each member to ensure the cross-sectional area of the conductive path. For example, in FIG. 13, each member is such that the cross-sectional area (shaded portion) of the conductive path of the connecting portion and the module connecting portion is at least three times the cross-sectional area (shaded portion) of the conductive path of each current extraction portion. It is necessary to increase the plate thickness.

  Compared with this, when the direction in which the plane of the communication portion (also known as module connection portion) expands is perpendicular to the direction of the conductive path of the communication portion, as in the form of FIGS. As described above, even if the communication portion is formed of a thin conductive material, the cross-sectional area of the conductive path of the communication portion can be ensured, and the communication portion can only flow the concentrated current. Has current capacity. In addition, in the forms of FIGS. 4 to 6, the module connecting portion also serves as the connecting portion. Therefore, compared with the form shown in FIG. 13, the form as shown in FIGS. 4 to 6 has a small volume occupied by current collecting members such as the module connecting part and the connecting part, and can reduce the physique of the entire module. That is, the size of each hollow cell remains the same, and the fuel cell as a whole can be miniaturized, and the power generation output density is increased. Further, the module connecting portion using the thin plate-like conductive material can be easily bent.

  The portion forming the serial connection portion between adjacent modules (the communication portion in the above example) is limited to a flat plate shape as long as the contact area between adjacent modules can be secured so that current can be taken out efficiently. For example, it may be narrow with respect to the left-right direction of the contact surfaces between the modules, or in order to reduce the weight of the module, a flat plate-like one that penetrates like a punch hole A structure may be formed. In addition, in the case of forming a series connection between adjacent modules by surface contact like the above-described communication portion, the contact surfaces facing each other do not have to be flat surfaces, and have an uneven shape that meshes with each other without a gap. May be. In this case, it is preferable that the flat surface obtained by averaging the unevenness is perpendicular to the direction in which the current flows.

  The specific distribution arrangement form of the current extraction part includes the form of the current collector or connection network (material, structure, etc.) provided with the current extraction part, the form of the current extraction part (material, structure, etc.), and the power generation amount of the hollow cell It depends on the etc. Moreover, a form may be restrict | limited depending on whether the current collection material or connection network which arrange | positions an electric current extraction part is provided in the inner surface of the hollow cell, or is provided in the outer surface.

  For example, in FIGS. 4 to 6, there are two current drawing portions 9 a and 9 b connected to the rod-shaped current collector 5 b, and the current draw portions are arranged at both ends of the rod-shaped current collector 5 b. As shown in FIG. 7, each hollow cell 6 constituting the hollow cell group 7 has a rod-shaped current collector 5b as an external current collector (cathode side current collector in the present embodiment), and When the plurality of hollow cells 6 and the rod-shaped current collector 5b are integrally knitted by the mesh-shaped current collector 5a, the rod-shaped current collector 5b in which current is collected by the mesh-shaped current collector 5a in contact with the surface of the cathode is It is easy to make a structure (such as a rod-shaped current collector having a diameter larger than that of the wire of the mesh-shaped current collector 5a) having a cross-sectional area of a conductive path that can efficiently flow the collected current, and it is easy to secure a current capacity. Therefore, the two current extraction parts arranged on the rod-shaped current collector 5b should be arranged with an interval of one half or more of the entire length of the rod-shaped current collector 5b in the longitudinal direction of the hollow cell (the axial direction of the hollow cell). Thus, it is possible to efficiently extract current from the rod-shaped current collector 5b. Even when two current extraction portions are provided without leaving a space of one half or more of the full length of the rod-shaped current collector 5b in the longitudinal direction of the hollow cell, the effect of shortening the current collection path can be obtained, but the rod-shaped current collector In order to efficiently extract the current from 5b, it is preferable to disperse and arrange the current drawing portions at intervals of one-half or more of the total length of the rod-shaped current collector 5b in the cell longitudinal direction.

  When three or more current extraction parts are connected on the rod-shaped current collector 5b as described above, the two current extraction parts that are farthest from each other are in the longitudinal direction of the hollow cell of the rod-shaped current collector 5b. What is necessary is just to arrange | position with the space | interval of 1/2 or more of full length, and can typically arrange | position at equal intervals in three or more places including the both ends of the said rod-shaped collector 5b.

4 to 6, anode-side current collectors 8a and 8b are arranged at two locations on both ends of the anode-side current collector 4 (columnar current collector), which is an internal current collector. In the present embodiment, the columnar current collector used as the anode-side current collector has a larger cross-sectional area than the wire of the mesh current collector 5a, like the rod-shaped current collector 5b, so that it is easy to ensure current capacity. For this reason, the two current extraction portions arranged on the columnar current collector 4 are efficiently arranged from the current collector 4 by disposing the current collector 4 at a distance of one half or more of the total length of the current collector 4 in the longitudinal direction of the hollow cell. The electric current can be taken out. Since the current collector is arranged in the portion where the surface is exposed to the outer surface, the anode is usually arranged at two locations on both ends as shown in FIG. 4 from the viewpoint of preventing the structure from becoming complicated. Side current drawing portions 8a and 8b are arranged.
However, as shown in FIG. 8, in the middle part of the hollow cell, the current collector 18 may be provided by exposing the internal current collector to the outer surface. In addition, for example, in order to further improve the current collection efficiency, or to increase the length of the hollow cell and respond to the increase in the amount of power generation associated therewith, three or more current extraction units may be provided. In that case, from the viewpoint of reducing current collection loss, it is desirable that the current extraction portions be provided at equal intervals at three or more locations including both ends in the longitudinal direction of the hollow cell.

  On the other hand, it is preferable that the connection positions of the respective current extraction units with respect to the module connection unit, that is, the connection points on the module connection unit of the current extraction unit are also distributed at two or more locations of the module connection unit. Usually, the connection positions of the current extraction units to the module connection units may be distributed in the same distributed arrangement form as the connection positions of the current extraction units to the respective current collectors or connection networks. Specifically, in the present embodiment shown in FIGS. 4 to 6, two current extraction parts are dispersedly connected to both ends of the communication part which is a module connection part.

  The structure of each current drawing part is not particularly limited. In addition to the comb structure as shown in FIG. 5, each current drawing part has a hole into which each rod-like or columnar current collector can be inserted, and each rod-like or columnar current collector is inserted into the hole. Thus, a structure in which each current collector and the current drawing portion are electrically connected may be used.

  4 to 6, the anode-side current extraction portions 8a and 8b and the anode-side module connection portion 8, and the cathode-side current extraction portions 9a and 9b and the cathode-side module connection portion 9 are made of a conductive material. The current draw-out part has a structure that is integrated with the module connection part, and each current collector or current collector is mutually connected. May be a part of the connection network connected to the module (see FIGS. 9 and 10), or may be a separate member from the module connection part and the current collector, and the module connection part and the current collector may be the current draw The process which is electrically connected via a part may be performed.

It does not specifically limit as an electroconductive material which forms each electric current extraction part and a module connection part, For example, a metal, a carbon material, electroconductive ceramics, electroconductive resin etc. are mentioned. These conductive materials may be used alone or in combination. Specific examples of the metal material include at least one metal selected from Al, Cu, Fe, Ni, Cr, Ta, Ti, Zr, Sm, In, and the like, or stainless steel (SUS). These alloys are mentioned.
The conductive material forming each current drawing part and module connection part may be appropriately selected depending on the structure of the module, and is SUS or Ti from the point of strength, Al, Ti, conductive from the point of weight reduction. From this point, Cu and Al are preferable. Moreover, the material which forms each current extraction part and module connection part can also be suitably selected according to the environment to which they are exposed. For example, when contacting with hydrogen, it is preferable to select a material having resistance to hydrogen embrittlement in which the metal material becomes brittle due to hydrogen adsorption. Further, when corrosion resistance is required, it is preferable to use Ti, SUS or the like.

In the present embodiment, both the anode-side module connection portion and the anode-side current collector, and the cathode-side module connection portion and the cathode-side current collector are connected via two or more lead portions, In the fuel cell of the present invention, at least one of the anode side and the cathode side of the hollow cell may be such that the module connection part and the current collector or connection network are connected via two or more current extraction parts. In order to further improve the above-mentioned effects obtained by improving the current collection efficiency and the current collection efficiency, it is preferable that both the anode side and the cathode side have the above-described structure.
Further, in order to further improve the above-mentioned effects obtained by improving the current collecting efficiency and improving the current collecting efficiency, all the modules incorporated in the fuel cell of the present invention and connected in series are connected to each hollow cell. On the anode side and / or the cathode side, the current collector or the connection network and the module connection part are preferably connected by the two or more current extraction parts.

In addition, in the present embodiment shown in FIGS. 4 to 6, in addition to the anode-side current collector 4, a cathode-side rod-like current collector 5 b is also inserted in the comb-shaped structure 10 of the anode-side current extraction portions 8 a and 8 b. The anode-side current extraction portions 8a and 8b and the cathode-side rod-shaped current collector 5b are appropriately insulated. Similarly, in the comb-shaped structure 11 of the cathode-side current extraction portions 9a and 9b, the anode-side current collector 4 is inserted in addition to the cathode-side rod-shaped current collector 5b, and the cathode-side current extraction portions 9a and 9b are appropriately connected. Insulation with the anode current collector 4 is performed.
Each anode-side current collector and cathode-side current collector inserted into the comb-shaped structure groove of each current draw-out part is an adhesive while maintaining electrical connection between each module connection part and the current collector as necessary. You may fix using etc.

  8 to 11 show another embodiment of the present invention. FIG. 8 is a perspective view of the module of the present embodiment, and a part thereof is cut out and omitted for convenience. FIG. 9 shows a part of the hollow cell group 7 incorporated in the module of FIG. 8 and only the current extraction parts connected to the hollow cell group.

  FIG. 10 shows a connection state of the mesh current collector (external current collector, cathode side current collector 5a in this embodiment) and the module connection portion (cathode side module connection portion 9 in this embodiment) of FIG. Is a diagram for explaining the above, and a part thereof is omitted. 10 (10A) is a CC sectional view of FIG. 8 (corresponding to the CC sectional view of FIG. 9), and FIG. 10 (10B) is a DD sectional view of FIG. 8 (corresponding to the DD sectional view of FIG. 9).

  FIG. 11 illustrates the connection state of the internal current collector (in this embodiment, the anode-side current collector 4) and the module junction (in this embodiment, the anode-side module connection portion 8) in FIG. It is a figure for doing, Comprising: A part is abbreviate | omitted. 11 (11A) is an AA cross-sectional view of FIG. 8, and FIG. 11 (11B) is a BB cross-sectional view of FIG.

In the module shown in FIG. 8, the anode-side current collector (in this embodiment, the internal current collector) 4 and the anode-side module connection portion 8 of each hollow cell 6 are formed as shown in FIGS. 8 and 11. The current collector 4 is connected to both ends of the current collector 4 via anode-side current extraction portions 18 distributed in a total of five locations, ie, three locations that equally divide the middle portion of the current collector 4 in the cell longitudinal direction (divide into four). ing. In the present embodiment, each hollow cell 6 has the anode-side current collector 4 exposed at both ends thereof, and the anode-side current collector 4 is also present at three locations in the middle part that divides the hollow cell into four equal parts. The anode-side current extraction portion 18 is disposed in these five exposed portions.
Then, the current drawn by the plurality of anode-side current drawing portions 18 distributed and arranged on the anode-side current collector 4 is collected at the anode-side module connection portion 8.

In the present embodiment, as described above, the five current extraction portions 18 are dispersedly arranged in the internal current collector (columnar current collector) 4 that is the anode-side current collector. At this time, the connection position of each of the current drawing portions 18 distributed to the current collector 4 is determined in each region of the electrode where each region of the current collector 4 from which current is drawn by each current drawing portion 18 collects current. When the amount of generated current and the current capacity of the current collector 4 are compared, it is preferable that the generated current amount be in a position where the current capacity is equal to or less than the current capacity.
Here, the amount of generated current in each region of the electrode from which each region of the current collector (or connection network) from which current is drawn by each current extraction unit collects current is defined via the current collector (or connection network). This is the amount of generated current for each region of the electrode from which current is drawn by each current drawing portion. In other words, it is the amount of generated current in each of the areas that are handled by the individual current extraction units. At this time, each region of the current collector (connection network; for example, a net-shaped current collector 5a described later) from which current is drawn by each current lead-out portion is in the form of the current collector (connection network), the shape of the current lead-out portion, the cell itself. It varies depending on unevenness in power generation performance and unevenness in current collection at each current extraction unit. Therefore, although it is difficult to uniquely determine each of the regions, a region of the current collector (connection network) from which current is drawn by a certain current extraction unit is divided into a plurality of currents distributed in the current collector (connection network). Of the drawers, the current collector (the connection network) between the current drawers adjacent to the current drawer may be regarded as an area that is equally divided. For example, in the example of the internal current collector 4 of the present embodiment, the current extraction portion 18a provided in the intermediate portion of the internal current collector has two current extraction portions (18 or 18a) adjacent to the current extraction portion 18a. It can be considered that current is drawn from the region of the internal current collector sandwiched between the midpoints.

Specifically, when a copper columnar body having a diameter of 1 mm (cross-sectional area of about 0.78 mm ² ) is used as the internal current collector 4, generally, copper can pass a current of 5 A per 1 mm ^2. The current capacity of the current collector 4 is about 3.9A. At this time, if each hollow cell is a tube-type cell (power generation effective area 4.71 cm ² ) having an effective power generation length of 150 mm and an outer diameter of 1 mm, and the power generation performance is 0.64 A per 1 cm ² , The amount of current is determined to be about 3A. That is, in the case of a hollow cell having a cell length of 150 mm, even if the current collector 4 is provided in the internal current collector 4, the cell's power generation current can be sufficiently passed. It can be seen that by providing the lead portion, current can be collected efficiently by shortening the current path.
However, when a 600 mm hollow cell having a cell length of 4 times is used, the amount of generated current of the hollow cell is 4 times 12A, so that at least 4 current draw parts are internally connected to each current draw part. By arranging the power generation current in each region of the electrode through which the current is drawn through the current collector 4 so as not to exceed the current capacity of the internal current collector 4, that is, at a position where it is 3.9 A or less, the power generation of the cell The current can be drawn by the current drawing unit without waste. At this time, in order to reliably draw out the generated current by the current extraction unit without waste, five or more current extraction units are equally divided in the cell longitudinal direction between the both ends of the internal current collector 4 and the intermediate portion sandwiched between the two ends. It is preferable to provide in such a position.
At this time, each current drawing portion has a current capacity sufficient to allow a current drawn by each current drawing portion from the internal current collector 4 to flow.

  In the embodiment of FIG. 8, each anode-side current extraction portion 18 has the same comb structure 10 as the current extraction portion of the embodiment shown in FIG. 4, and a plurality of anode-side current collectors per groove 10a. 4 is inserted and electrically connected. The anode-side current collector 4 inserted into the groove 10a may be fixed using an adhesive or the like while maintaining electrical connection with each current drawing portion 18. At this time, the connection portion between the anode-side current collector 4 exposed at the intermediate portion of each hollow cell 6 and the anode-side current extraction portion 18 (18a) connected to the intermediate portion of the anode-side current collector 4 is The reaction gas flowing through the inner surface of the hollow cell to be supplied to the anode and the reaction gas flowing through the outer surface of the hollow cell to be supplied to the cathode are gas-sealed so as not to leak from each other.

  On the other hand, in the module shown in FIG. 8, each hollow cell 6 constituting the hollow cell group 7 includes only a net-like current collector 5 a as a cathode-side current collector (external current collector) (see FIG. 3). A plurality of hollow cells 6 are integrally knitted by the net-like current collector 5a. That is, the plurality of hollow cells 6 share the mesh current collector 5a, and the mesh current collector 5a is a connection network in which the cathode current collectors of the hollow cells 6 are electrically connected to each other.

In the present embodiment, the net-like current collector 5a, which is a connection network of cathode-side current collectors, and the cathode-side module connection portion 9 include a plurality of cathode-side current extraction portions 17 arranged in a distributed manner as shown in FIGS. .., And the current drawn from the cathode-side network current collector 5 a by each current drawing portion 17 is collected at the cathode-side module connecting portion 9.
Each cathode-side current extraction portion 17 is an end portion of the cathode-side network current collector 5a located on the hollow cell 6a arranged at the end of the hollow cell group 7 knitted by the cathode-side network current collector 5a. In other words, they are distributed and arranged in a plurality of locations of a net-like current collector 5 a that functions as a cathode-side current collector shared by a plurality of hollow cells 6. A large number of each current drawing portion 17 is arranged at a short interval as compared with the columnar current collector 4 which is the anode current collector described above. At this time, each current drawing portion 17 is connected to the mesh current collector 5a, which is a connection network of the cathode current collector, so that the current of each hollow cell 6 collected on the mesh current collector 5a can be efficiently extracted. Are distributed.

  Here, in order to efficiently take out the current of each hollow cell 6 collected on the mesh current collector 5a, the connection position of each current drawing portion 17 to the mesh current collector 5a is the conductive path of the mesh current collector 5a. Cross-sectional area (cross-sectional area of the wire constituting the mesh current collector), how to wind the wire of the mesh current collector, the material of the mesh current collector 5a, the power generation performance of each hollow cell, and the hollow cell sharing the mesh current collector It is desirable to consider various factors such as the number of

Specifically, as with the anode side, the connection positions of the respective current extraction units arranged in a distributed manner to the connection network are such that each region of the connection network (current collector 5) from which current is extracted by each current extraction unit 17 is current. When the amount of generated current in each region of the electrode that collects current and the current capacity of the connection network are compared, it is preferable that the amount of generated current be equal to or less than the current capacity.
For example, when the wire constituting the mesh current collector 5a is a copper wire having a diameter of 0.5 mm (cross-sectional area of about 0.196 mm ² ), the copper wire can generally flow a current of 5 A per 1 mm ^2. The current capacity of a copper wire having a diameter of 0.5 mm is 0.98A. At this time, if each hollow cell is a tube-type cell (power generation effective area 4.71 cm ² ) having an effective power generation length of 150 mm and an outer diameter of 1 mm, and the power generation performance is 0.64 A per 1 cm ² , The amount of generated current is determined to be about 3A, and the total amount of generated current of the five hollow cells is 15A. That is, when the net-like current collector 4a composed of the copper wire as described above is shared by five hollow cells, the current draw-out portion 17 that is the end of the copper wire is reticulated by each current draw-out portion 17. By arranging at least 16 locations (15A / 0.98A≈15.3) so that the amount of generated current in each region of the electrode through which current is drawn through the current collector 5a is 0.98 A or less. The generated current of the cell can be drawn out without waste by the current drawing unit.

  As described above, when a plurality of hollow cells 6 share a net-like cathode-side current collector 5a (connection network) as shown in FIG. 9, depending on the number of hollow cells and the power generation performance of each cell, etc. The net-shaped current collector 5a has a small cross-sectional area of the conductive path, and has a smaller current capacity than the rod-shaped current collector 5a or the columnar current collector 4. Therefore, in order to efficiently extract current from the mesh current collector 5a, a current extraction portion interposed between the mesh current collector 5a and the module connection portion is disposed on the rod current collector 5a or the column current collector 4. It is desirable that a large number of them are arranged at a short interval as compared with the current drawing portion.

In the present embodiment, the end of the mesh current collector 5a serving as the cathode-side current extraction portion 17 can use the original end of the wire constituting the mesh current collector 5a, and can hold tension for braiding a plurality of hollow cells. Within the range, the middle part of the wire of the mesh current collector may be appropriately cut to form an end portion, which may be used as a current drawing portion.
There is no particular limitation on the method of connecting the current extraction portion, which is the end portion of the mesh current collector, to the module connection portion. For example, a method for fixing and connecting the current extraction part, which is the end of the wire of the mesh current collector, to the module connection part by soldering or the like, or a hole in which the end of the wire of the mesh current collector can be inserted into the module connection part And a method of inserting an end portion of the wire into the hole.

  As described above, in the present embodiment, by arranging a large number of current extraction parts for connecting the anode side module connection part and the anode side current collector, the cathode side module connection part and the cathode side current collector (connection network), respectively, The current collection path from the current collection material connected to the hollow cell to the module connection is shortened, and the current collection efficiency is improved. Further, the fuel cell of the present embodiment using only the net-like current collector 5a as the cathode-side current collector and not using the rod-like current collector, the above-described implementation using both the rod-like current collector 5b and the net-like current collector 5a as the cathode-side current collector. Compared with the embodiment, there is an advantage that the volume occupied by the current collector can be reduced by the amount of the rod-shaped current collector.

  Further, the connection position of each of the current extraction units arranged in a distributed manner to the connection network indicates the amount of generated current in each region of the current collecting material from which current is extracted by each current extraction unit or each region of the electrode from which each region of the connection network collects current. And the current capacity of the current collector or connection network, if the generated current amount is less than the current capacity, when using a hollow cell with a long cell length, or collecting current Even when a current collector or a connection network having a small current capacity is used for the hollow cell, current can be collected without loss. In this way, the method of distributing and arranging the current extraction parts in consideration of the amount of generated current is used when a hollow cell having a long cell length is used, or a current collector or connection network having a small current capacity with respect to the hollow cell to be collected. In the case of using, it is highly effective and can be suitably applied. This distributed arrangement method can be applied to forms other than the present embodiment, for example, the embodiments shown in FIGS.

In addition, in this embodiment, the dispersion | distribution arrangement | positioning form of the current extraction part connected with a mesh-shaped current collection material is not limited to what is shown in FIGS. 8-10, In addition to the current collection efficiency mentioned above, the structure of a module etc. are considered. And can be designed as appropriate.
In FIG. 8, when the current extraction part is arranged in the net-shaped current collector into which the hollow cells 6 arranged in the second and third stages are arranged in the hollow cell group 7, The resulting wire is extended from the position of the second- and third-stage hollow cells 6 to the module connection portion 9 and connected to the module connection portion 9.

In the present embodiment, the anode-side module connection portion 8 and the cathode-side module connection portion 9 respectively form upper and lower surfaces facing each other in a box-like module, and the adjacent module has an anode-side module of one module. The connecting portion 8 and the cathode-side module connecting portion 9 of the other module are brought into contact with each other and brought into surface contact with each other to be connected in series.
In one module, the anode-side current extraction unit 18 and the anode-side module connection unit 8 and the cathode-side current extraction unit 17 and the cathode-side module connection unit 9 are electrically insulated. ing.

In the fuel cell of the present invention, the method of supplying the reaction gas to the inner surface side and the outer surface side of each hollow cell is not particularly limited.
For example, in FIGS. 4 and 5, the inner surface gas flow paths 12 (12 a, 12 a, 12 b, and 12 b) flow reaction gas (hydrogen gas in the present embodiment) to the inner surfaces of the hollow cells 6 at both ends of the hollow cell group 7. 12b) is provided. Further, on the body side of each hollow cell 6 of the hollow cell group 7, the surface gas flow path 13 through which the reaction gas (air in the present embodiment) flows on the outer surface side of each hollow cell 6. Is provided. These two inner surface gas channels 12a and 12b and the outer surface gas channel 13 form a space on the outer surface side of the hollow cell 6 between both ends and the body of each hollow cell 6 of the hollow cell group 7. Gas partitioning properties are secured by partitioning walls (not shown).

One of the gas flow paths 12a, 12b for the inner surface is a supply path (upstream) for supplying hydrogen gas into the hollow of the hollow cell, and the other is hydrogen gas (a part of hydrogen is consumed from the hollow of the hollow cell) This is a discharge path (downstream) through which (unreacted hydrogen gas) is discharged, and the gas pressure difference determines which is upstream and which is downstream. The hollow cell 6 has one open end connected to the supply path of the inner surface gas flow path 12 and the other open end connected to the discharge path of the inner surface gas flow path 12 so that hydrogen gas flows in the hollow. It has become.
Further, the inner surface gas flow paths 12a and 12b between the modules 100 adjacently connected in series are connected at the inner surface gas flow path connection portions 15a and 15b provided on the surface where the modules 100 come into contact with each other. .

  In the module 100 shown in FIGS. 4 and 5, the outer-surface gas flow path 13 has an opening 13 a in the side surface where the width of the module 100 is narrow, and the reactive gas is supplied and discharged from the opening 13 a into the module 100. It can be done. Further, since the module 100 has contact surfaces 8c and 9c of the flat module connection portions 8 and 9 at the contact surface with the adjacent module, the supply and discharge of the reaction gas can be performed from the narrow side surface portion. However, it is also possible to provide an external gas flow path connection portion (not shown) for each module 100 on the contact surface with the adjacent module, and to communicate the external gas flow paths of the adjacent modules.

  Further, in the present embodiment, air is used as the reaction gas supplied to the outer surface of the hollow cell 6, so the outer surface gas flow path 13 is an open space in which air freely enters and exits from the outside of the module 100. It may be a closed space communicating with an air supply source and a discharge path.

The module 100 shown in FIGS. 4 and 5 is further provided outside the two inner gas flow paths 12a and 12b, and inside the hollow current collector 5b of the external current collector (cathode side current collector in this embodiment) 5. 5c has cooling water flow paths 14a and 14b for circulating the cooling water. One of the cooling water flow paths 14a and 14b is a supply path (upstream) for supplying cooling water to the hollow interior 5c of the rod-shaped current collector 5b, and the other is an exhaust path for discharging cooling water from the hollow interior of the rod-shaped current collector 5b. (Downstream). The rod-shaped current collector 5b has one open end connected to the supply path of the cooling water flow path 14 and the other open end connected to the discharge path of the cooling water flow path 14, so that the cooling water flows through the hollow 5c. . The cooling water is circulated in order to keep the temperature in the module at a predetermined temperature and / or to prevent the temperature from rising excessively.
Moreover, the cooling water flow paths 14a and 14b of the modules 100 adjacently connected in series are connected at the cooling water flow path connection portions 16a and 16b provided on the surface where the modules 100 contact each other.

  In the module shown in FIG. 8, the outer-surface gas flow path 13 has an opening 13a in the side surface where the width of the module is narrow, and the reaction gas can be supplied and discharged from the opening 13a into the module. Yes. The gas passage for the inner surface is omitted.

In the hollow cell group 7, the hollow cells 6 are aligned at a predetermined interval, that is, an interval having a certain regularity, and are usually aligned at a constant interval (equal interval). If the hollow cells are not arranged at equal intervals, the flow of the reaction gas supplied to the outer surface side electrode of the hollow cell will not be uniform. This is because the power generation efficiency of the battery is reduced. In particular, when the interval between the hollow cells in the direction perpendicular to the direction in which the reaction gas supplied to the outer surface of the hollow cell flows is not constant, the flow of the reaction gas tends to be largely biased. It is preferable to align the hollow cells so that the distance between the hollow cells in the direction perpendicular to the direction in which the reaction gas supplied to the outer surface flows is constant.
In addition, in the case of a dead-end type in which the hollow cell is opened at only one end, the gas flow path for the inner surface consists only of a supply path for supplying the reaction gas into the hollow from the open end. An open end is connected to the road.

It is a perspective view which shows one example of a hollow type (tube shape) cell used for this invention. It is sectional drawing of the tubular cell shown in FIG. It is a perspective view which shows one example of the tubular cell used for this invention. It is a figure which shows one example of the module with which the fuel cell of this invention is equipped. FIG. 5 is a partially exploded view of the module of FIG. 4. It is the schematic which shows the state which connected the module shown in FIG. 4 in series. It is a figure which shows the tubular cell group with which the module of FIG. 4 is equipped. It is a figure which shows one example of the module with which the fuel cell of this invention is equipped. It is a figure which shows a part of each current extraction part connected to the hollow type cell group with which the module of FIG. 8 is equipped, and a hollow type cell group. FIG. 10 (10A) is a diagram for explaining a connection state of the mesh current collector (external current collector, in the present embodiment, the cathode side current collector) in FIG. Fig. 10 (10B) is a DD cross-sectional view in Fig. 8. FIG. 11 (11A) is a cross-sectional view taken along the line AA in FIG. 8, illustrating a connection state of the internal current collector (in this embodiment, the anode side current collector) in FIG. FIG. 11 (11B) is a BB cross-sectional view in FIG. It is a figure explaining the current capacity of the communication part in the U-shaped cell module connection part, and the current capacity of a current extraction part. It is a conceptual diagram for demonstrating the relationship between the direction where an electric current flows into an adjacent module from an electric current extraction part, and the cross-sectional area (plate thickness) of a connection part and a module connection part.

Explanation of symbols

1 ... Hollow electrolyte membrane (perfluorocarbon sulfonic acid membrane)
2 ... Anode (inner electrode)
3 ... Cathode (outside electrode)
4 ... Anode-side current collector (internal current collector)
5 ... Cathode side current collector (external current collector)
6 ... Hollow type cell 7 ... Hollow type cell group 8 ... Anode side module connection part 8a, 8b ... Anode side current extraction part 8c ... Communication part 9 ... Cathode side module connection part 9a, 9b ... Cathode side current extraction part 9c ... Communication Part 10: Comb structure (10a: groove, 10b: tooth)
11 ... Comb structure (11a: groove, 11b: tooth)
12 (12a, 12b) ... Gas channel for inner surface 13 ... Gas channel for outer surface 13a ... Opening 14 (14a, 14b) ... Cooling water channel 15 (15a, 15b) ... Gas channel connection portion for inner surface 16 (16a 16b) ... Cooling water gas flow path connection part 17 ... Cathode-side current extraction part 18 ... Anode-side current extraction part 100 (100a, 100b, 100c) ... Module

Claims (11)

A hollow cell having a hollow electrolyte membrane, a pair of electrodes provided on an inner surface and an outer surface of the hollow electrolyte membrane, and a current collector connected to each of the pair of electrodes, and at least one end of which is open A fuel cell in which two or more modules connected in parallel are connected in series,
Each module is connected to the anode side current collector of each hollow cell or connected to a connection network in which the anode side current collector of each hollow cell is connected to each other, and an anode side module connection part for collecting currents; A cathode-side module connecting part that collects current by connecting to a cathode-side current collector of each hollow cell or a connection network in which cathode-side current collectors of each hollow cell are connected to each other is provided.
Between adjacent modules, the anode side module connection part of one module and the cathode side module connection part of the other module are connected and connected in series.
In at least one of the modules, at least one of the current collectors on the anode side and the cathode side of each hollow cell, or the connection network connecting them and the module connection part are dispersed in connection positions with respect to the current collector or connection network. A fuel cell, characterized in that the fuel cell is connected through two or more arranged current drawing parts.   In all the modules, at least one of the current collectors on the anode side and the cathode side of each hollow cell, or the connection network and the module connection portion connecting them together are connected to each other through the distributed current extraction portions. The fuel cell according to claim 1, which is connected.   3. The fuel cell according to claim 1, wherein connection positions of the respective current drawing parts that are dispersedly arranged with respect to the module connecting part are dispersedly arranged at two or more locations on the module connecting part.   The fuel according to any one of claims 1 to 3, wherein the module connection portion has a structure in which each of the current extraction portions and a communication portion that electrically communicates each of the current extraction portions are integrally formed. battery. The modules that are adjacent and connected in series are in surface contact with the communication part of the anode side module connection part of one module and the communication part of the cathode side module connection part of the other module. Connected in series,
5. The fuel cell according to claim 4, wherein the contact surfaces of the two communication portions are perpendicular to a direction in which the current concentrated in the communication portions flows to the communication portions of adjacent modules connected to the communication portions. .   The module connecting portion has a shape obtained by forming a plate-like conductive material into a U-shape so that two plate-like current extraction portions are disposed at both ends of the plate-like communication portion, The communication portion is disposed so as to be parallel to the longitudinal direction of the hollow cell, and the current extraction portion is approached and connected to the current collector of the hollow cell from the side surface direction of the hollow cell. The fuel cell according to claim 5. Among the anode-side current collector and the cathode-side current collector, a current collector connected to an electrode provided on the outer surface of the hollow electrolyte membrane is a rod-shaped current collector disposed in parallel with the hollow cell, and the plurality of the current collectors A hollow cell and a net-like current collector that weaves a rod-shaped current collector provided in the plurality of hollow cells,
The fuel cell according to any one of claims 1 to 6, wherein two or more current extraction portions are dispersedly arranged on each rod-shaped current collector of each hollow cell.   The farthest positions of the respective current extraction portions distributed and arranged on the rod-shaped current collectors of the hollow cells are at least one-half of the total length of the rod-shaped current collectors in the longitudinal direction of the hollow cells. The fuel cell according to claim 7, wherein the fuel cells are arranged at intervals.   9. The fuel cell according to claim 8, wherein among the current drawing portions, those having the farthest positional relationship are provided at both ends of the rod-shaped current collector in the longitudinal direction of the hollow cell.   Among the anode side current collector and the cathode side current collector, the current collector connected to the electrode provided on the outer surface of the hollow electrolyte membrane is a connection network made of a net current collector that weaves the plurality of hollow cells, The fuel cell according to any one of claims 1 to 5, wherein two or more current extraction portions are dispersedly arranged on a connection network made of the mesh current collector.   The connection position of each of the current drawn portions arranged in a distributed manner with respect to the current collector or the connection network is determined by each of the current collecting material or each region of the connection network from which the current is drawn by each current draw portion. The power generation current amount in a region and the current capacity of the current collector or the connection network are compared, and the power generation current amount is a position where the current capacity is equal to or less than the current capacity. Fuel cell.

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