JP2006086045A - Flat fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable to form a series structure or a parallel structure of a plurality of planar cells by removing short circuit of an anode electrode and a cathode electrode and by wiring of low resistance. <P>SOLUTION: This is a fixing tool in which a conductor provided for securing conductivity of the cathode electrode and the anode electrode is a fixing tool in order to fix the end plate, and every end plate is constituted of an insulator or has a surface to which an electric insulating treatment is applied. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell, and more particularly to a planar fuel cell used for a portable power source or the like in which a plurality of single cells are arranged in a row or in a row on a plane and electrically connected in series.

FIG. 9 is a partially sectional side view showing the configuration of a conventional planar fuel cell (see, for example, Patent Document 1). In FIG. 9, 1a to 1c (sometimes represented by 1) are conductive Z-shaped connection plates, 2 is a cathode side end connection plate, 3 is an anode side end connection plate, 4a to 4d (4) (May be represented) is an air electrode, 5a-5d (may be represented by 5) is an electrolyte layer, 6a-6d (may be represented by 6) is a fuel electrode, 7a-7d (represented by 7) The single cells 7a to 7d are configured such that the air electrodes 4a to 4d and the fuel electrodes 6a to 6d face each other with the electrolyte layers 5a to 5d interposed therebetween. 8 is an air electrode side gas seal part, 9 is a fuel electrode side gas seal part, 10 is a fuel electrode side seal material filling part, 11 is an air electrode side seal material filling part, 12a, 12b (may be represented by 12) Are current terminals provided in the single cells 7a and 7d arranged at both ends of the series connection, 12a being an anode side current terminal and 12b being a cathode side current terminal. Reference numeral 13 denotes a fuel manifold box, and reference numeral 14 denotes a fuel manifold lid. The fuel manifold box 13 and the fuel manifold lid 14 constitute a fuel manifold. 15 is a fuel inlet plug, 16 is a fuel outlet plug, 17 is a fastening screw, and 19 is an electrical insulating plate. In FIG. 9, four single cells 7 are arranged in a line on a plane and are electrically connected in series in the horizontal direction by the Z-shaped connecting plate 1. 9 is assembled to each single cell 7a integrated with each gas seal portion 8 and 9 on the fuel manifold in which the fuel manifold box 13 and the fuel manifold lid 14 are joined. ~ 7d and each connecting plate (Z-shaped connecting plates 1a to 1c and anode side and cathode side end connecting plates 2 and 3) are arranged as shown in FIG. In this way, the integrated series connection unit of single cells is placed, and the electrical insulating plate 19 is further placed thereon, and tightened with a predetermined pressure through the fastening screw 17 into the screw hole 23 penetrating each member.
JP 2002-56855 A

  However, in the configuration of the above-mentioned patent document, the fastening screw for fixing the whole cell is a through-hole provided in a Z-shaped connection plate connected to an air electrode (hereinafter referred to as a cathode electrode) in the same single cell. And two through-holes provided in another Z-shaped connecting plate connected to the fuel electrode (hereinafter referred to as the anode electrode), the two connecting plates connected to the same cell are There is a possibility of short circuit.

  Further, if the through hole is enlarged to avoid the short circuit as described above, the assembly accuracy is lowered. Further, in order to improve the assembly accuracy, a bush such as a bush formed of an insulating material according to the diameter of the through hole is used. There is a problem that a hollow cylindrical insulator must be provided, and the number of parts increases.

Then, this invention is made | formed in view of the said subject,
An electrolyte made of a resin having proton conductivity, a membrane electrode assembly comprising two or more sets of catalyst layers arranged in an array on both surfaces of the electrolyte, a gas diffusion layer corresponding to each of the catalyst layers, a current collector In a planar fuel cell composed of an anode electrode and a cathode electrode comprising body layers and arranged in a plane so that the same electrode is aligned on the same surface, the above-described planar fuel cell is pressed from the anode electrode side and the cathode electrode side. A pair of end plates, a conductor installed through the cathode electrode and the anode electrode, and a connector for connecting the conductor and the current collector layer, and one single cell for at least two cells The anode electrode and the cathode electrode of the other single cell are electrically connected in series.

  Also, it is composed of an electrolyte composed of a resin having proton conductivity, a membrane electrode assembly composed of a catalyst layer disposed on both sides of the electrolyte, a gas diffusion layer, and an anode electrode and a cathode electrode each composed of a current collector layer. In a flat type fuel cell in which two or more single cells are arranged in a plane so that the same poles are arranged on the same plane, a pair of end plates that hold and fix the plurality of single cells from the anode side and the cathode side A conductor installed through the cathode electrode and the anode electrode, and a connector for connecting the conductor and the current collector layer, and the anode electrode of one unit cell and the other unit of at least two cells. It is good also as a structure which connects the cathode electrode of a cell electrically in series.

  In the above configuration, the conductor provided for securing the conduction between the cathode electrode of the one single cell and the anode electrode of the other single cell connected in series is a fixture for fixing the end plate, Are either made of an insulator, or are electrically insulated on the surface.

  The above-described fixture is a screw or a bolt for fixing the end plate, or a leaf spring or a rivet for fixing the end plate.

  Further, when a screw or a bolt is used as the fixing tool, the connecting tool may have the function of the washer.

  Further, the end plate described above is characterized in that at least one of the cathode electrode side and the anode electrode side is integrally molded.

  According to the planar fuel cell according to the present invention, the above structure makes it possible to form a series structure of a plurality of planar cells with simple and low resistance wiring. Also, by adding the two functions of the end plate pressing pressure and electrical conduction path to the bolt, the problem of short circuit between the anode and cathode can be eliminated, and the entire structure can be simplified. Realize the reduction of points. Furthermore, by making the anode and cathode separate, assembly and disassembly are facilitated and individual cell adjustments are possible. Also, by changing the connection method, it is possible to easily change from serial connection to parallel connection.

  Hereinafter, embodiments of a planar fuel cell according to the present invention will be described in detail with reference to the drawings. Constituent elements represented by the same reference numerals in the drawings are common to the drawings and indicate the same constituent elements.

  FIG. 1 is a configuration diagram of a planar fuel cell according to the present invention, which is an example of a basic form of the present invention. 1, a planar fuel cell 100 has the same shape as a membrane electrode assembly (hereinafter referred to as MEA) 101 in which a plurality of catalyst layers are formed in an array on the same electrolyte membrane, and the MEA is used as a cathode electrode. A cathode electrode side end plate 102a, an anode electrode side end plate 102b (hereinafter also referred to as an end plate 102), an anode chamber 103, and a current collector layer 104. A gas diffusion layer (not shown) provided for each catalyst layer of the MEA 101 and sandwiched between the current collector layers 104, a packing material 105 for ensuring gas sealability, and a conductive material for fixing the respective constituent members. The fixing device 106 includes a connection device (not shown) that connects the current collector layer 104 and the fixing device 106.

  The fixing device 106 uses bolts in FIG. 1 and is fixed by a nut (not shown) from the anode electrode side. The fixing device 106 is provided with a screw hole on the concave end surface of the anode chamber 103 in accordance with the position of the fixing device 106. A convex portion may be provided and fixed by tightening the bolt and the anode chamber. In addition, as long as the fixing device 106 is a conductive material, the fixing device 106 may have a leaf spring shape that is fixed with the cathode electrode end plate 102a and the anode electrode end plate 102b sandwiched therebetween, or the cathode electrode end plate 102a. And a leaf spring shape that is fixed with the anode chamber 103 interposed therebetween. Further, the fixing device 106 has a pin shape, and in FIG. 1, the cathode electrode end plate 102 to the anode chamber 103 are fixed by an adhesive, and electrical conductivity between the cathode electrode side and the anode electrode side is ensured through the through hole. Any configuration may be used as long as the electrical conductivity of the cathode electrode side and the anode electrode side is ensured and all the components are fixed. The material of the fixture 106 is a material excellent in corrosion resistance, mechanical strength, and electrical conductivity, and preferably stainless steel or the like is employed. Further, the fixing tool may be made hollow and a lead-out path for discharging the aqueous solution or off-gas staying in the anode chamber by power generation may be installed.

  For the current collector layer 104, any material can be used as long as it is excellent in electrical conductivity and gas permeability. Preferably, foam metal is used, and in particular, foam nickel is used. To do.

  Details of the MEA 101, the end plate 102, the anode chamber 103, and the packing material 105 will be described later with reference to FIGS.

  FIG. 2 is a side view of the planar fuel cell of the present invention, and the connection between the fixture and the connection tool and the connection between the cathode electrode and the anode electrode will be described in detail with reference to FIG.

  2, the planar fuel cell of the present invention includes an MEA 201 in which a plurality of catalyst layers are arranged on the same electrolyte membrane, and a current collector layer 202 (described as 202a to 202d in the figure) on both sides of the MEA. , A gas diffusion layer (not shown) sandwiched between the MEA 201 and the current collector layer 202, and a connector 203 (203a and 203b in the figure) connected to the current collector layer 202 and further connected to a bolt 204 described later. Description), bolts 204 and nuts 205 used as fixtures, electrode terminals 206 (described as 206a and 206b in the figure), cathode electrode side end plate 207 formed of an insulator, and also formed of an insulator. The anode electrode side end plate 208, the gas sealing property 209, and an anode chamber (not shown).

  In FIG. 2, bolts 204 and nuts 205 are used in FIG. 2. However, as described in FIG. 1, any fixture can be used as long as it has electrical conductivity and fixes all components. Details are omitted to avoid duplication.

  In FIG. 2, the connector 203 can be applied to any material having excellent electrical conductivity, but is preferably the same type of metal as the current collector layer 202. For example, nickel foam is used as the current collector layer 202. In this case, a nickel wire or a nickel plate is used. In addition, if the connection device 203 is connected to the current collector layer 202 and has a mechanical strength and electrical conductivity, all methods such as connection by solder and connection by a conductive adhesive are applicable. Although possible, it is preferable to avoid contact with dissimilar metals and connect by resistance welding, laser welding, ultrasonic welding, or the like. Also, the connection between the connector 203 and the bolt 204 can be applied as long as the connection method is also excellent in electrical conductivity, such as solder connection, conductive adhesive connection, resistance welding, laser welding, and ultrasonic welding. However, it is preferable that the connector 203 itself becomes a washer for the bolt 204 and the nut 205, or that the connector 203 is connected to the washer by the connection method described above, and the bolt 204 and the nut 205 are securely tightened. The connection tool and the bolt 204 are fixed in contact with each other.

  Details of the MEA 201, the cathode electrode side end plate 207, the anode electrode side end plate 208, and the packing material 209 will be described later with reference to FIGS.

  Hereinafter, the configuration of the series connection using the MEA 201, current collector layers 202a to 202d, connectors 203a and 203b, bolts 204, nuts 205, and electrode terminals 206a and 206b in FIG. 2 will be described in detail.

  In the cell 1 composed of the MEA 201 and the current collector layers 202a and 202c, the current collector layer 202a serves as an anode, and the current collector layer 202c serves as a cathode. The connector 203b and the bolt 204 and the nut 205 that are connected and fixed to the connector 203b. The connecting members 203a connected and fixed to the bolts 204 all have the same potential as the current collector layer 202c. The connection tool 203a is connected to the current collector layer 202b on the anode side of the cell 2 composed of the adjacent MEA 201 and the current collector layers 202b and 202d. As described above, the cell 1 and the cell 2 adjacent to each other are connected in series via the bolt 204, and similarly, the cells adjacent to each other are sequentially connected in series, and power can be obtained from the terminal electrode terminals 206a and 206b. it can.

  Similarly, the current collector layer 202a and the bolt 204 are connected via the connector 203a, the current collector layer 202b and the bolt 204 are connected via the connector 203c (not shown), and the current collector is connected via the connector 203b. By connecting the body layer 202c and the bolt 204 and connecting the current collector layer 202d and the bolt 204 via a connector 203d (not shown), the cells can be easily connected in parallel.

  FIG. 3 is a configuration diagram of the MEA 101 shown in FIG. 1 in the planar fuel cell of the present invention.

  As shown in FIG. 3, the MEA 101 includes an electrolyte membrane 301, a catalyst layer 302 installed in an array on both surfaces of the electrolyte membrane 301, and a through hole 303 through which the fixture is passed. As shown in FIG. 3, the catalyst layers 302 may be arranged side by side in a grid, may be arranged concentrically, or may be installed in any other shape. Further, the catalyst layers 302 may all have the same shape as shown in FIG. 3, or the shape may be changed so as to absorb the variation in the output of each catalyst layer caused by the fuel contact. Further, as shown in FIG. 3, the catalyst layer 302 may be disposed on the same electrolyte membrane 301, or the catalyst layers are respectively disposed on the electrolyte membrane divided by the lattice-like substrate. Also good.

  FIG. 4 is a configuration diagram of the end plates 102a and 102b shown in FIG. 1 in the planar fuel cell of the present invention.

  As shown in FIG. 4, the end plates 102a and 102b fix the base member 401, a pressing bar 402 that comes into contact with the current collector layer to give a pressing force, a through hole 403 through which the fixture is passed, and the pressing bar 402. A groove 404 is formed.

  As the material of the base material 401, any ceramic material such as alumina, epoxy glass material, resin material such as acrylic, polycarbonate, and polyethylene can be used as long as it has an excellent mechanical strength. Preferably, the polyacetal is excellent in bending strength.

  The pressing bar 402 may be a rod-like body as shown in FIG. 4 or a lattice shape, and has a structure that does not impede gas permeation, and the catalyst layer, gas diffusion layer, current collector Any structure can be applied as long as it has a structure that ensures adhesion by applying pressure to the layer and maintains good electron conductivity. Furthermore, as shown in FIG. 4, the pressing rod 402 may be positioned by being fitted into the groove 404, or may be a structure that is joined in advance to the base material 401. The presser bar may be an insulator or a conductor. In particular, in the case of a conductor, any material that is excellent in corrosion resistance, mechanical strength, and electrical conductivity can be applied, and stainless steel is preferably used. In this case, the connecting tool may be connected to the presser bar.

  With regard to the position of the through hole 403, particularly the position of the through hole 403 through which the fixture for connecting the anode and cathode in series is secured, the mechanical strength of the end plate is ensured and the distance between the through holes is short. Although it will not be limited if it is a structure with low resistance, Preferably it is set as the structure densely packed in the center part of the end plate. Furthermore, it is set as the structure which arrange | positions the through-hole which lets through the fixing tool for a connection with the anode chamber mentioned later to a base material outer peripheral part. Further, the positions of all the through holes 403 are arranged symmetrically, and fastening with the same force reduces the in-plane pressing force variation.

  FIG. 5 is a configuration diagram of the anode chamber 103 shown in FIG. 1 in the planar fuel cell of the present invention.

  As shown in FIG. 5, the anode chamber 103 includes a base 501, a supply port 502, a discharge port 503, and a through hole 504 through which a fixture is passed.

  Since the material of the substrate 501 is the same as that of the end plate, it is omitted to avoid duplication.

  Fuel is supplied from the supply port 502, but the planar fuel cell of the present invention can be applied to all fuel cells such as PEFC, DMFC, PAFC, MCFC, and SOFC. Any fuel can be applied to the fuel supplied from the supply port 502 as long as it is a fuel for driving the fuel cell. Preferably, a hydrogen rich gas is supplied from the supply port 502. Further, the discharge port 503 may be a mechanism that is normally closed and opened when discharging an aqueous solution or off-gas that stays in the anode chamber, or is always open and supplied with fuel and the above-described aqueous solution. A mechanism for continuously or intermittently discharging off-gas may be used. Further, a flow path may be provided in the concave portion of the anode chamber so that fuel efficiently and uniformly hits the MEA.

  When the fixture is a bolt, the through hole 504 may be formed with a screw groove.

  FIG. 6 is a configuration diagram of the packing material 105 shown in FIG. 1 in the planar fuel cell of the present invention.

  As shown in FIG. 6, the packing material 105 includes a base 601, a through hole 602, and a through hole through which the fixture is passed.

  The substrate 601 can be applied to any material having gas sealing properties such as silicon rubber and nitrile rubber, but is preferably butyl rubber.

  The through hole 602 is opened in accordance with the position of the catalyst layer of the MEA.

  Since the through hole 603 is the same as the through hole 405 in FIG. 4, the description is omitted to avoid duplication.

  FIG. 7 shows a modification of the planar fuel cell of the present invention. 7, components having the same configuration, function, and operation as those shown in FIG. 2 are denoted by the same reference numerals, and detailed description thereof is omitted to avoid duplication.

  In FIG. 7, an electrolyte membrane 701 (described as 701 a and 701 b in the drawing) is installed for each cell divided by a frame 702. The packing material 703 is installed on the outermost surface of the cell formed in an array.

  As the connection method of each cell in FIG. 7, series connection and parallel connection are the same as the example shown in FIG. 2, and detailed description is omitted to avoid duplication. Further, the configuration and material of the packing material 703 are the same as in the example shown in FIG. 6, and therefore, detailed description is omitted to avoid duplication.

  FIG. 8 is a configuration diagram of the MEA 701 and the frame 702 in FIG. FIG. 8 shows a modification of the MEA 101 shown in FIG. 3, and the same constituent elements as those in FIG. 3 are indicated by the same reference numerals, and detailed description thereof is omitted to avoid duplication.

  In FIG. 8, the electrolyte membrane 801 is divided into frames 802 and installed for each cell, and the catalyst layer 302 is formed on both surfaces. Any material can be used for the frame 802 as long as it is an insulator having excellent mechanical strength, such as ceramic materials such as alumina, epoxy glass materials, resin materials such as acrylic, polycarbonate, and polyethylene. It is a polyacetal excellent in strength.

It is a perspective view which shows the structure of the planar fuel cell of this invention. It is a side view of the planar fuel cell of this invention, and is a figure which shows the electrical connection of a cell. It is a figure which shows the structural example of MEA of the planar fuel cell of this invention. It is a figure which shows the structural example of the end plate of the planar fuel cell of this invention. It is a figure which shows the structural example of the anode chamber of the planar fuel cell of this invention. It is a figure which shows the structural example of the packing material of the planar fuel cell of this invention. It is a side view of the 1st modification of the planar fuel cell of this invention, and is a figure which shows the electrical connection of a cell. It is a figure which shows the structural example of MEA in the 1st modification of the planar fuel cell of this invention. It is a figure which shows the structure of the prior art example of a planar fuel cell.

Explanation of symbols

201 Electrolyte membrane 202a, 202b, 202c, 202d Current collector layer 203a, 203b Connector 204 Bolt 205 Nut 206a, 206b Electrode terminal 207 Cathode pole side end plate 208 Anode pole side end plate 209 Packing material

Claims (8)

An electrolyte made of a resin having proton conductivity, a membrane electrode assembly comprising two or more sets of catalyst layers arranged in an array on both surfaces of the electrolyte, a gas diffusion layer and a current collector respectively corresponding to the catalyst layers In a planar fuel cell comprising an anode electrode and a cathode electrode comprising layers,
A pair of end plates for holding and fixing the planar fuel cell from the anode electrode side and the cathode electrode side, a conductor installed through the cathode electrode and the anode electrode, the conductor and the collector A planar fuel, comprising: a connecting member for connecting electrical layers, wherein the anode electrode of one single cell and the cathode electrode of the other single cell are electrically connected in series with respect to at least two cells. battery. An electrolyte made of a resin having proton conductivity, a membrane electrode assembly made of a catalyst layer disposed on both surfaces of the electrolyte, and an anode electrode and a cathode electrode made of a gas diffusion layer and a current collector layer In a planar fuel cell in which two or more single cells are arranged,
A pair of end plates for holding and fixing the plurality of single cells from the anode electrode side and the cathode electrode side, a conductor installed through the cathode electrode and the anode electrode, the conductor and the collector A planar fuel cell comprising: a connecting member for connecting electrical layers, wherein the anode electrode of one unit cell and the cathode electrode of the other unit cell are electrically connected in series with respect to at least two cells. .   3. The planar type according to claim 1, wherein the conductor is a fixture for fixing the end plate, and each of the end plates has an electrical insulation treatment on an insulator or a surface. Fuel cell.   The planar fuel cell according to claim 3, wherein the fixing tool is a screw or a bolt for fixing the end plate.   The planar fuel cell according to claim 3, wherein the fixture is a leaf spring for fixing the end plate.   The planar fuel cell according to claim 3, wherein the fixture is a rivet for fixing the end plate.   The planar fuel cell according to any one of claims 1 to 4, wherein the connector is a washer.   4. The planar fuel cell according to claim 1, wherein in the end plate, one of the cathode electrode side and the anode electrode side is integrally formed. 5.

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