JP2006172850A - Fuel cell stack - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell stack capable of achieving a small size. <P>SOLUTION: The fuel cell stack has laminated unit cells 14 and end plates 11a, 11b installed which tightens so as to impress a prescribed surface pressure on the unit cells at both ends of the laminated unit cells. A cover 15 is installed which is made of an insulating material to cover the fuel cell stack and a wiring 16 is arranged at the inner face of the cover, and a cell side contact terminal 18 for detecting power generation characteristics of the unit cells is installed at a prescribed unit cell. This cell side contact terminal and the wiring installed at the inner face of the cover are constructed so as to be connected, and using the wiring, the power generation characteristics of the unit cells is detected. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell stack, and more particularly to downsizing of a fuel cell stack.

  A fuel cell system is a device that directly converts chemical energy contained in fuel into electrical energy, and supplies a fuel gas containing hydrogen to the anode of a pair of electrodes provided on both surfaces of an electrolyte layer made of a solid polymer membrane. At the same time, an oxidant gas containing oxygen is supplied to the other cathode, and electric energy is taken out from the electrode by utilizing the following electrochemical reaction that occurs on the surface of the pair of electrodes on the polymer film side ( For example, see Patent Document 1).

Anodic reaction: H ₂ → 2H ⁺ + 2e ⁻ (1)
Cathodic reaction: 2H ⁺ + 2e ⁻ + (1/2) O ₂ → H ₂ O (2)
Here, as a fuel gas supplied to the anode, a method of directly supplying from a hydrogen storage device or a method of supplying a reformed hydrogen-containing gas by reforming a fuel containing hydrogen is known. Examples of the hydrogen storage device include a high-pressure gas tank, a liquefied hydrogen tank, and a hydrogen storage alloy tank. As the fuel containing hydrogen, natural gas, methanol, gasoline or the like can be considered. Air is generally used as the oxidant gas supplied to the cathode.

  A vehicle that travels by a motor as a drive source using electric power from the fuel cell has been researched and developed. In such a fuel cell system mounted on a vehicle, it is required to reduce the weight and size of the fuel cell system.

  In addition, in order to control the flow rate of the fuel gas and oxidant gas that controls the power generation amount of the cell, and to protect the motor when an abnormal voltage of the cell is detected, the output of each cell constituting the fuel cell A voltage is detected.

As a means for detecting the output voltage of each cell, there is a technology for providing a voltage contact retainer for restraining the voltage contact provided in the cell as a separate component and detecting the output voltage by connecting the voltage contact retainer and the voltage contact of the cell. (See Patent Document 2).
JP-A-8-106914 JP 2003-86205 A

  However, since a voltage contact retainer connected to the voltage contact of the cell is newly added to the constituent parts of the fuel cell, there is a problem that the size of the fuel cell is increased.

  The present invention has been made paying attention to such conventional problems, and an object of the present invention is to provide a fuel cell stack that suppresses an increase in size for detecting an output voltage of a cell.

  The present invention provides a fuel cell stack provided with a pair of end plates for fastening stacked single cells in the stacking direction, a cover made of an insulating material covering the fuel cell stack, and the power generation characteristics of the single cell in the predetermined single cell. A cell-side contact terminal for detection; wiring is provided on the inner surface of the cover; and the cell-side contact terminal and the wiring provided on the inner surface of the cover are connected to each other. Detect the power generation characteristics.

  In the present invention, since the wiring connected to the contact terminal of the single cell is provided on the inner surface of the cover, it is not necessary to provide a separate part for connecting to the contact as in the prior art, and the fuel cell stack is reduced in size and weight. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a cross-sectional view showing a configuration of a fuel cell stack configured by stacking a plurality of cells 14, and a pair of end plates 11a and 11b are installed so as to sandwich the stacked cells 14 from both sides. The The end plates 11a and 11b hold the stacked cells 14 at a predetermined surface pressure by a fastening member (not shown). Here, the cell 14 is a so-called single cell. The single cell is a polymer electrolyte membrane (not shown), a membrane / electrode assembly including an anode and a cathode that sandwich the membrane, and a membrane / electrode assembly. Separator.

  As shown in the drawing, an insulating plate 12 and a current collecting plate 13 are disposed between the end plates 11 a and 11 b and the cell 14. Further, a cover 15 made of a thin plate-like insulating material is provided so as to cover the whole unit cell 14 or a part of the stacked unit cell 14 and is fixed between the end plates 11a and 11b at both ends.

  As shown in FIG. 2, the cover 15 is formed with a printed wiring 16a for detecting the output voltage of each single cell of the fuel cell stack. Here, the printed wiring refers to wiring formed by printing a conductive pattern on the surface or surface of an insulating substrate (insulating member) and the inside thereof in order to connect components based on circuit design. The end of the printed wiring 16a is connected to the wiring-side contact terminal 17a via an insulated wire 16b. The wiring side contact terminal 17 a is connected to a cell side contact terminal 18 provided in the cell 14. As shown in FIG. 3, in order to insulate the printed wiring 16a formed on the cover 15, an insulating coating 19 is applied on the printed wiring 16a.

  Cell-side contact terminals 18 are installed in the stacked cells 14 for each predetermined number of cells, connected to the wiring-side contact terminals 17a, and the output voltage of the cells 14 is detected externally through the printed wirings 16a to the fuel cell stack. It is used to control the amount of fuel gas supplied and to detect cell abnormalities.

  Thus, since the printed wiring is provided on the cover 15 that covers the stack in order to detect the output voltage of the cells 14 of the fuel cell stack, there is no need to provide wiring and wiring fixing members as separate members, and the fuel cell can be downsized. In addition, the weight can be reduced.

  Further, by using the printed wiring, the work of attaching the single wiring to the fixing member is omitted, so that the workability can be improved. Further, by using the printed wiring, it is possible to eliminate the possibility of erroneous wiring, and it is possible to improve the reliability of the fuel cell by detecting an appropriate cell output voltage.

  The printed wiring 16a and the electric wire 16b can be connected by a connector or soldering, or the electric wire 16b can be an extension of the printed wiring 16a. Further, instead of the printed wiring, the electric wire 16b can be extended and attached to the cover 15.

  FIG. 3 is a diagram illustrating an example of the configuration of the wiring-side contact terminal. In this embodiment, the wiring side contact terminal 17b is configured to be fixed inside the cover 15, and the shape is set so as to be connected to the cell side contact terminal 18 in a fixed state.

  In this embodiment, since the wiring side contact terminal 17b is fixed to the cover 15, it can be directly connected to the printed wiring 16a. By omitting the electric wire 16b, the number of parts, the weight, and the cost can be reduced. In addition, the power density at the time of assembling the fuel cell stack can be improved.

  FIG. 4 is a diagram illustrating another example of the configuration of the wiring-side contact terminal. The wiring side contact terminal 17c shown in FIG. 4 is fixed to the cover 15 similarly to the wiring side contact terminal of FIG. The wiring side contact terminal 17c is in sliding contact with the cell side contact terminal 18 in the stacking direction. The contact area of the wiring side contact terminal 17c is larger than the contact area of the cell side contact terminal 18 by a predetermined dimension. . Thus, the contact between the contact terminals is facilitated by increasing the contact area of one of the contact terminals. Therefore, by providing a dimensional margin for the contact area of one of the contact terminals, it becomes possible to absorb errors in the dimensions of components and assembly errors, improving the efficiency of assembly work and providing reliable contact terminals. Can be improved.

  FIG. 5 shows an example of the arrangement of the contact terminal portions. The cell-side contact terminal 18 that comes into contact with the wiring-side contact terminal 17c is provided on a predetermined surface of the outer peripheral surface of the cell. However, the cell-side contact terminal 18 does not have to be formed linearly with respect to the stacking direction. The outer peripheral surfaces may be formed offset from each other in a direction orthogonal to the stacking direction. By placing the contact terminals offset in this way, it is possible to arrange the contact terminals in consideration of assembly errors due to cell stacking, and it is possible to install the contact terminals in each adjacent cell, The output voltage at the cell can be detected.

  The present invention is not limited to the embodiment described above, and various modifications and changes can be made within the scope of the technical idea, and it is obvious that these are equivalent to the present invention.

It is a block diagram of the fuel cell stack of a present Example. It is a block diagram of a contact terminal part. It is a block diagram of a wiring side contact terminal part. It is detail drawing of a wiring side contact terminal part and a cell side contact terminal part. It is an example of arrangement | positioning of a wiring side contact terminal part and a cell side contact terminal part.

Explanation of symbols

11a End plate 11b End plate 12 Insulating plate 13 Current collecting plate 14 Single cell 15 Cover 16a Printed wiring 16b Electric wire 17a Wiring side contact terminal 17b Wiring side contact terminal 18 Cell side contact terminal 19 Insulating coating

Claims (9)

A single cell comprising a polymer electrolyte membrane, a membrane / electrode assembly comprising an anode and a cathode sandwiching the polymer electrolyte membrane, and a separator sandwiching the membrane / electrode assembly;
In a fuel cell stack comprising a pair of end plates that clamp the stacked single cells in the stacking direction,
A cover made of an insulating material covering the stacked single cells;
A cell-side contact terminal for detecting power generation characteristics in the predetermined single cell;
Wiring is applied to the inner surface of the cover, and the cell side contact terminal and the wiring applied to the inner surface of the cover are configured to be connected,
A fuel cell stack, wherein power generation characteristics of a single cell are detected using the wiring.   The fuel cell stack according to claim 1, wherein the wiring is a printed wiring.   The fuel cell stack according to claim 1, wherein the wiring is insulated.   The fuel cell stack according to claim 1, wherein a wiring side contact terminal is provided at an end of the wiring, and the wiring side contact terminal and the cell side contact terminal are connected.   The fuel cell stack according to claim 4, wherein the wiring side contact terminal is integrally fixed to the inner surface of the cover and is in contact with the cell side contact terminal.   6. The fuel cell stack according to claim 5, wherein an area of a contact surface between the wiring side contact terminal and the cell side contact terminal is larger than that of one contact terminal.   2. The cell-side terminal is provided on a predetermined outer peripheral surface of the single cell, and each cell-side terminal is provided offset from each other in a direction orthogonal to the stacking direction of the single cells. Or 5. The fuel cell stack according to 4.   The fuel cell stack according to claim 1, wherein the cover is spanned between the end plates and fixed. The fuel cell stack according to claim 1, wherein the end plate is fastened so that a predetermined surface pressure is generated in the single cell.

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