JPH0660905A - Collected fuel cell - Google Patents

Abstract

PURPOSE:To provide a thin and lightweight collected fuel cell without using the overall pressure contact method having problems on the strength of the fuel cell and an increase of contact resistance in constituting the collected fuel cell built up with multiple unit cells. CONSTITUTION:A unit cell 2 has a fuel electrode chamber 15 in common with a unit cell 1, and the unit cell 2 is laminated with the fuel electrode chamber 15, a fuel electrode 23, an electrolyte chamber 21, an oxidant electrode 22, and an oxidant electrode chamber 24 in this order. The oxidant electrode chamber 24 is used in common with a unit cell 3 arranged in succession. Unit cells are connected together via collecting connectors 100, and external extracting terminals of adjacent unit cells are connected to form a collected unit. Multiple units are likewise connected via external terminals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell in which unit cells are connected in series and assembled.

[0002]

2. Description of the Related Art FIG. 5 shows an example of the configuration of a known unit cell of a methanol fuel cell. Reference numeral 1 is an electrolyte layer, and a methanol electrode 2 and an air electrode 3 are arranged on both sides of the electrolyte layer 1 with the electrolyte layer 1 in between. A grooved current collector plate 4 is further arranged on both of these electrodes. Grooves serving as passages for anolite or air are formed on both surfaces of the grooved current collector plate 4, and this one grooved current collector plate 4 is used for the anolite room of the adjacent cell, that is, A fuel electrode chamber or an air chamber, that is, an oxidant electrode chamber is secured. The electrolyte layer 1, the methanol electrode 2, the air electrode 3, and the grooved current collector plate 4 are pressed against each other to form one unit cell.

Usually, a plurality of the cells are stacked in series by pressure contact and assembled to form a cell stack (Japanese Utility Model Laid-Open No. 3-121659).

[0004]

In order to collect current from the electrodes in the assembled fuel cells having the above-mentioned conventional structure, that is, the cell stack, the current is collected from the grooved current collector plates pressed against the electrodes. There is. In the pressure contact between the current collector plate and the electrode, the contact pressure needs to be as high as possible in order to reduce the contact resistance. When a large number of unit cells are stacked as an assembled fuel cell, high pressure is applied to the entire fuel cell. In this case, if the strength of the current collector plate itself is not uniform, the current collector plate is damaged, which is an obstacle in promoting the reduction in size and weight of the fuel cell.
Further, when the assembled fuel cells are configured by pressure contact, there is a problem that contact resistance increases due to variations in contact surface pressure between each current collector plate and the electrode.

In view of the above, the present invention does not rely on the full pressure welding method, which is problematic in increasing the strength and contact resistance of the fuel cell in constructing a fuel cell in which a plurality of unit cells are built up and assembled, Moreover, it is an object of the present invention to provide an assembled fuel cell which is thin and lightweight.

[0006]

In order to solve the above-mentioned problems, the present invention relates to a unit cell constructed by stacking a fuel electrode chamber, a fuel electrode, an electrolyte, an oxidant electrode and an oxidant electrode chamber in this order. In a fuel cell in which a plurality of cells are assembled, the cells are arranged so that at least one of the fuel electrode chambers and the oxidant electrode chambers of the adjacent cells are shared, and each electrode has an external lead terminal and The electrical connection between the cells is made into an assembled fuel cell, which is characterized by connecting external lead terminals.

[0007]

In the assembled fuel cell of the present invention, the same electrode of each of two adjacent unit cells can share one fuel electrode chamber or one oxidant electrode chamber, so that two fuel electrodes can be shared. The polar chamber can be narrower than the volume of the chamber or the oxidant polar chamber.

[0008]

Embodiment 1 FIG. 1 shows an example of one unit of an assembled fuel cell of the present invention, and FIG. 2 shows a sectional view taken along line AA of FIG. This unit is configured by combining four unit cells of unit cell 1, unit cell 2, unit cell 3, and unit cell 4. The unit cell 1 includes an oxidant electrode chamber 14, an oxidant electrode 12,
It is composed of an electrolyte 11, a fuel electrode 13, and a fuel electrode chamber 15. Subsequently, the unit cell 2 includes a fuel electrode chamber 15, a fuel electrode 23,
It is composed of an electrolyte 21, an oxidant electrode 22, and an oxidant electrode chamber 24. The other unit cells 3 and 4 have the same configuration.

These unit cells are stacked back to back so that the fuel electrode chambers or the oxidant electrode chambers of the adjacent unit cells are shared with each other so that the fuel electrode chambers or the oxidant electrode chambers are shared with each other. Together, they form one fuel electrode chamber or one oxidant electrode chamber. That is, the unit cell 2 has the fuel electrode chamber 15
Is shared with the unit cell 1, and the unit cell 2 is configured such that the fuel electrode chamber 15, the fuel electrode 23, the electrolyte 21, the oxidant electrode 22,
The oxidant electrode chambers 24 are laminated in this order, and the oxidant electrode chambers 24 are shared by the unit cells 3 arranged subsequently.

The structure of the electrodes used in each cell is shown in FIG. 3 as an example. FIG. 3 is a configuration diagram of the oxidizer electrode 22 of the unit cell 2 and the fuel electrode 33 of the unit cell 3, in which each electrode has current collectors 221 and 331 each having a grid-like opening and an electrode reactant 223,
It is configured by joining with 333. Each current collector 22
External lead-out terminals 222, 332 for electrically connecting the cells to each other are provided at two points of the current collector 1, 331 in a point-symmetrical manner on one current collector. The configuration of the electrodes is the same in other unit cells.

Further, as shown in FIG. 1, an external lead-out terminal 132 is provided at the edge of the fuel electrode 13 of the unit cell 1, and in the unit cell 4, an external lead-out terminal 422 is provided at the oxidizer electrode 42. It is shown that it is being done. These external lead terminals 132, 422 can be connected to adjacent units of the assembled fuel cell. Adjacent single cells are connected in series by a current collector connector 100 at each external lead terminal provided on each electrode. A connection block or a cable made of a good conductor metal is used for the current collector / connector 100, and is connected by forming a bridge-shaped route. Current collecting connector 1 illustrated in FIGS. 1 and 2.
For U00, a U-shaped flat cable is used, and by fixing the foot portion of this flat cable as a leaf spring to the external lead-out terminal by screwing, adjacent unit cells can be crimped and fixed. . The electrical connection is
External lead-out terminals of different kinds of electrodes of adjacent unit cells form bridge-shaped paths. Routes that are close to each other are arranged so that their positions are far from each other, that is,
They are arranged so as to be shifted, and by separating the connection positions from each other in this way, it has an effect of preventing electrical interference caused by the external lead terminals of the same polarity of the adjacent cells.

As shown in FIG. 3, the current collector 221 has two external lead terminals 222 and 222, and the current collector 3
Similarly, 31 has two external lead terminals 332, 332. When connecting a plurality of cells, in order to reduce the contact resistance between adjacent cells, two external lead terminals 222, 22 formed on both sides of the periphery of the current collector plate.
Both 2, 332 and 332 need to be connected to other cells. FIG. 2 shows that the external lead-out terminals on both sides of the current collector plate are electrically connected by the current collector connector 100.

FIG. 4 is a perspective view of the whole unit of this assembled fuel cell. A fuel discharge / oxidant supply manifold 51 is provided in the upper portion of this unit, and a fuel supply / oxidant discharge manifold 52 is provided in the lower portion of this unit. Further, external lead-out terminals 132, 422 are exposed at both ends of this unit, so that the unit can be connected to another adjacent unit to expand the overall size of the further assembled fuel cell.

[0014]

Since the present invention is constructed as described above,
Two adjacent same poles can share one fuel electrode chamber or one oxidant electrode chamber, allowing a narrower electrode chamber than two fuel electrode chambers or oxidant electrode chambers. Therefore, it is possible to reduce the thickness and the weight of the assembled fuel cells as a whole.

In addition, even in the case of connecting units made up of a plurality of cells, as in the case of connecting the cells, they can be connected using the external lead terminals of each unit, so that they can be assembled at any scale. The fuel cell can be easily manufactured.

[Brief description of drawings]

FIG. 1 shows an example of one unit of an assembled fuel cell of the present invention.

2 shows a cross-sectional view of AA of FIG.

FIG. 3 shows a structure of an electrode used in the present invention.

FIG. 4 shows a perspective view of the entire unit of the assembled fuel cell of the invention.

FIG. 5 shows a configuration example of a known methanol fuel cell unit cell.

[Explanation of symbols]

11,21,31,41 Electrolyte 12,22,32,42 Oxidant electrode 13,23,33,43 Fuel electrode 14,24,44 Oxidant electrode chamber 15,35 Fuel electrode chamber 51 For fuel discharge and oxidant supply Manifold 52 Fuel supply / oxidant discharge manifold 100 Current collectors 221, 331 Current collectors 132, 222, 332, 422 External extraction terminals 223, 333 Electrode reactant

Claims (1)

[Claims] 1. A fuel cell in which a plurality of unit cells configured by stacking a fuel electrode chamber, a fuel electrode, an electrolyte, an oxidizer electrode, and an oxidizer electrode chamber in this order are assembled: (1) Fuel of adjacent unit cells The unit cells are arranged so that at least one of the polar chambers and the oxidant polar chamber is shared, (2) each electrode has an external lead terminal, and (3) electrical connection between adjacent unit cells is external. An assembled fuel cell, characterized in that it is carried out by connecting lead terminals.