JPH11339828A - Fuel cell stack with cell voltage measurement terminal - Google Patents

Abstract

(57) Abstract: Provided is a fuel cell stack having a terminal for measuring an individual cell voltage suitable for a thin separator. SOLUTION: As a terminal for voltage measurement of each cell of the fuel cell, it is integrated with the separator on the end face of the separator, or is pin-shaped by joining by soldering, projection welding or the like.
A fuel cell stack with a cell voltage measuring terminal, wherein a terminal having a projecting shape such as an L-shape is provided. The terminal is provided with a + terminal on the first end face of the anode side separator and a − terminal on the third end face of the cathode side separator, or a + terminal of the anode side separator and a − terminal of the cathode side separator. Displace them on the same end face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a fuel cell stack.

[0002]

2. Description of the Related Art Fuel cells use a fuel gas (main component: hydrogen).
And electrochemical reaction between oxygen and air to obtain an electromotive force. The electromotive force of each individual cell is at most 0.7 V
Therefore, one fuel cell stack is generally constructed and used by stacking tens to hundreds of cells.

[0003] As means for knowing whether or not each cell constituting the fuel cell stack is in a normal state, measurement of each cell voltage is performed. If one cell is damaged during operation of the fuel cell, the voltage of that cell drops significantly, so measuring the voltage of individual cells indicates that an abnormality has occurred, and immediately stops the operation of the cell can do. If the detection of the occurrence of the abnormality is delayed, the damage may spread.

The prior art is disclosed in Japanese Patent Application Laid-Open No. 9-283166.
The publication discloses a structure in which a relatively thick carbon material separator is provided with a round hole and a banana clip is inserted.

[0005]

The above-mentioned prior art method can be used when the separator is thick to some extent, but cannot cope with the case where the separator is made thin to reduce the size of the fuel cell. The present invention provides a fuel cell stack having a cell voltage measuring terminal suitable for a thin separator.

[0006]

Means for Solving the Problems In order to solve the above technical problems, the technical means taken in claim 1 of the present invention comprises an electrode unit and a separator, and comprises a fuel gas containing hydrogen as a main component. A fuel cell stack for converting oxygen or air into electricity by reacting in the electrode unit, wherein a protruding voltage measuring terminal is provided on the separator. .

An advantage of this technical means is that it is not necessary to make a hole in the end face of the separator, so that a terminal for voltage measurement can be attached even when the thickness of the separator becomes thin.

According to a second aspect of the present invention, there is provided the fuel with a cell voltage measuring terminal according to claim 1, wherein said terminal is a pin-shaped projection perpendicular to an end face of the separator. It is a battery stack.

An advantage of this technical means is that a socket of a lead wire for measuring a voltage can be easily connected to a terminal.

According to a third aspect of the present invention, there is provided a fuel cell with a cell voltage measuring terminal according to the first aspect, wherein the terminal is an L-shaped projection with respect to an end face of the separator. It is a stack.

An advantage of this technical means is that the amount of protrusion of the socket connected to the terminal can be suppressed, and the outer size of the stack can be reduced.

[0012] The technical measures taken in claim 4 of the present invention are as follows: the terminal is connected to the first end face of the separator on the anode side by +
The fuel cell stack with cell voltage measuring terminals according to claim 1, wherein a terminal is disposed at a third end face of the separator on the cathode side.

The effect of this technical means is that even if the battery cells become thinner and the separators approach each other, the measuring terminals come into contact with each other and the possibility of short-circuiting decreases.

According to a fifth aspect of the present invention, in the above-mentioned method, the terminals are arranged such that a positive terminal of the anode-side separator and a negative terminal of the cathode-side separator are shifted from each other on the same end face. A fuel cell stack with a cell voltage measuring terminal according to claim 1.

The effect of this technical means is to reduce the possibility that the measuring terminals come into contact with each other and cause a short circuit, and at the same time, the voltage measurement wiring can be taken out from only one of the side surfaces of the stack. Of the fuel cell stack can be miniaturized.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described.
This will be described with reference to the drawings.

FIG. 1 is an external view of a polymer electrolyte fuel cell stack 1 provided with a voltage measuring terminal according to the present invention. Many cells 2 are stacked. An L-shaped voltage measuring terminal 3 is provided on a side surface in front of the fuel cell stack 1. The terminal may be integrated with the separator, or may be separately manufactured and joined by soldering, projection welding, or the like.

The fuel cell stack 1 is of a type in which a positive terminal is disposed on a first end face of a separator on the anode side and a negative terminal is disposed on a third end face of the separator on the cathode side. Is attached with a negative terminal.

Here, the first end face may be any of the four end faces of the separator. In addition, although the third end face is an end face opposite to the first end face, a negative terminal may be arranged on the second and third end faces.

FIG. 2 is an AA sectional exploded view of FIG. 1 for explaining the arrangement of the separator and the electrode unit. In this sectional exploded view, two cells are configured as one unit with three types of separators.

Between the separator 4a and the separator 4b, an electrode unit 5a is provided.
The electrode unit 5b is disposed between the two.

Between the separator 4a and the electrode unit 5b,
Air flows between the separator 4b and the electrode unit 5a, and hydrogen flows between the separator 4a and the electrode unit 5a and between the separator 4c and the electrode unit 5b.

There is no electrode unit between the separators 4b and 4c, and cooling water flows. The voltage measuring terminals 3 are arranged at the ends of the separators 4a and 4c.

The electrode units 5a and 5b have a structure in which a polymer ion exchange membrane 8 as an electrolyte is sandwiched between two electrodes, a hydrogen electrode 6 as a cathode and an air electrode 7 as an anode. The separators 4a, 4b, and 4c are formed with grooves serving as passages for air, hydrogen, or cooling water.

Normally, one cooling water passage 16 is included in one unit as in this embodiment. Of course, the cooling water passages 16 may be arranged for each cell, or a dedicated cooling water passage may not be provided.

Since the voltage measuring terminal 3 of this embodiment can be manufactured with a thickness equal to or less than the thickness of the separator 4, it can be attached even if the separator 4 is thin. or,
Since the + terminal and the-terminal are provided on the opposite side surface of the fuel cell stack 1, an electric short circuit does not occur and the terminal is safe.

The + terminal and the-terminal can be provided on the same side surface of the fuel cell stack 1 so as to be shifted vertically. In this case, the possibility of an electrical short can be reduced, and at the same time, the lead wires of the + terminal and the-terminal can be combined, so that the fuel cell stack can be downsized.

There are various methods for attaching the voltage measuring terminal. 3 to 5 show a separator 4 having a voltage measuring terminal.
FIG. The separator 4 of these embodiments is made of a metal such as aluminum or stainless steel.

In the separator 4, an air supply passage 9, a cooling water passage 10, a hydrogen supply passage 11, an air exhaust passage 12, and a hydrogen exhaust passage 13 are formed.

The four end surfaces of the separator 4 are a first end surface 17a, a second end surface 17b, and a third end surface 17b, respectively.
c, name fourth end face 17d.

FIG. 3 is a plan view of the separator 4 in which the pin-shaped voltage measuring terminal 3a is welded to the first end face by projection welding or the like. Here, the term “pin” refers to a rod-like shape protruding in a straight line, and may be a plate-like shape or a columnar shape such as a circle or a polygon.

FIG. 4 shows an L-shaped voltage measuring terminal 3b in FIG.
FIG. 10 is a plan view of the case 4 and the separator 4 integrally formed on the third end surface. Here, the L shape is obtained by bending the pin shape into an L shape.

FIG. 5 shows the pin-shaped voltage measuring terminal 11 as shown in FIG.
FIG. 10 is a plan view of the case 4 and the separator 4 integrally formed on the third end surface.

FIG. 6 shows a pin-shaped voltage measuring terminal 3d as shown in FIG.
Is an explanatory view in the case where the L-shaped voltage measuring terminal 3a is joined to the separator 4 by projection welding or the like.
It is a part of.

6 and 7 show the state before welding, and the lower figures show the state after welding. When produced integrally with the separator, a large amount of useless material is produced, but there is no such material in joining, and the cost can be reduced.

FIGS. 8 and 9 are explanatory diagrams showing a state in which a socket 15 having a lead wire 14 for measuring a voltage is attached to an L-shaped voltage measuring terminal 3b and a pin-shaped voltage measuring terminal 3c, respectively. FIG. 6 is an enlarged view of a part of the separator 4 shown in FIGS. Thus, the structure is such that the lead wire can be easily attached.

With the L-shaped voltage measuring terminal 3b, the projecting amount of the connected socket can be suppressed as compared with the pin-shaped voltage measuring terminal 3c.

[0038]

As described above, the present invention provides a fuel cell comprising an electrode unit and a separator, wherein a fuel gas containing hydrogen as a main component and oxygen or air are reacted in the electrode unit to convert the fuel gas into electricity. Since the fuel cell stack with the cell voltage measuring terminals is provided with a protruding voltage measuring terminal on the separator in the stack, it is a terminal suitable for a thin separator corresponding to miniaturization of the fuel cell. By connecting to the terminal with a socket or the like and measuring the voltage of each cell during fuel cell operation,
An abnormality in each cell can be detected quickly.

[Brief description of the drawings]

FIG. 1 is an external view of a fuel cell stack according to an embodiment of the present invention.

FIG. 2 is an exploded cross-sectional view illustrating an arrangement of a separator and an electrode unit.

FIG. 3 is a plan view of a separator having a pin-shaped voltage measurement terminal by bonding.

FIG. 4 is a plan view of a separator integrally provided with an L-shaped voltage measuring terminal.

FIG. 5 is a plan view of a separator integrally provided with a pin-shaped voltage measurement terminal.

FIG. 6 is an explanatory view of joining a pin-shaped voltage measurement terminal to a separator.

FIG. 7 is an explanatory view of joining an L-shaped voltage measuring terminal to a separator.

FIG. 8 is an explanatory view in which a socket is attached to an L-shaped voltage measuring terminal.

FIG. 9 is an explanatory view in which a socket is attached to a pin-shaped voltage measurement terminal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Fuel cell stack 2 ... Cell 3, 3a, 3b, 3c, 3d ... Voltage measurement terminal 4, 4a, 4b, 4c ... Separator 5a, 5b ... Electrode 6 ... Hydrogen electrode 7 ... Air electrode 8 ... Polymer ion exchange membrane 14 Lead wire 15 Socket 16 Cooling water passage 17a, 17b, 17c, 17d Separator end face

Claims (5)

[Claims] 1. A fuel cell stack comprising an electrode unit and a separator, wherein a fuel gas containing hydrogen as a main component reacts with oxygen or air in the electrode unit to convert the gas into electricity. A fuel cell stack with a cell voltage measuring terminal, comprising a voltage measuring terminal. 2. The fuel cell stack according to claim 1, wherein the terminal is a pin-shaped protrusion perpendicular to an end face of the separator. 3. The terminal according to claim 1, wherein said terminal is L
2. The fuel cell stack with cell voltage measuring terminals according to claim 1, wherein the fuel cell stack is shaped like a letter. 4. The terminal has a positive terminal on the first end face of the separator on the anode side and a negative terminal on the third end face of the separator on the cathode side.
The fuel cell stack with cell voltage measuring terminals according to claim 1, wherein terminals are arranged. 5. The fuel with a cell voltage measuring terminal according to claim 1, wherein the terminals are arranged such that the positive terminal of the anode side separator and the negative terminal of the cathode side separator are shifted on the same end face side. Battery stack.