JP2000285937A - Fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reinforce strength without increasing film thickness of a solid polymer film by forming a catalyst portion for an electrode with remaining fixing edges on both surfaces of the solid polymer film, arranging plates on both sides of the solid polymer film to structure a cell, and forming a reinforcing metal layers on the fixing edges. SOLUTION: Electrode catalyst portions 3c and 3e are integrally formed leaving fixing edges 51 to a substrate with a rib on both surfaces of a solid polymer film 3d. The electrode catalyst portions 3c and 3e are formed by scouring catalyst such as platinum and carbon into a paste shape and applying or thermally crimping it onto both surfaces of the solid polymer film 3d. Reinforcing metal layers 53 with thicknesses similar to thicknesses of the electrode catalyst portions 3c and 3e on the fixing edges 51 on both surfaces of the solid polymer film 3d. As the metal layers 53, metal materials high in conductivity and strength are used. Thus, since electrode catalyst portions are formed on the entire region of both surfaces of the solid polymer film including the fixing edges, reinforcement is performed without increasing film thickness of the solid polymer film, and fuel gas and the catalyst abut to each other thanks to recesses or projections on the electrode catalyst portions, and power generation performance is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell having a fuel cell stack for generating electric power by reacting fuel with oxygen in air.

[0002]

2. Description of the Related Art Generally, an electrode catalyst section is formed on both sides of a solid polymer membrane while leaving a fixed margin, and cells are arranged on both sides of the solid polymer membrane by arranging plates. 2. Description of the Related Art A fuel cell in which a plurality of fuel cells are stacked to constitute a fuel cell stack is known.

[0003] In this type of catalyst, a catalyst such as platinum is kneaded into a paste and carbon is kneaded into a paste. Part is formed.

[0004]

As the thickness of the solid polymer membrane becomes thinner, the power generation performance of the fuel cell can be improved.

Therefore, conventionally, in order to reinforce the strength of the solid polymer film, fibers are mixed into the solid polymer film at the manufacturing stage, or a plurality of solid polymer films are laminated. In this case, However, there is a problem that the film pressure is necessarily increased.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art and to reinforce the strength of the solid polymer film without greatly increasing the film pressure of the solid polymer film. To provide a fuel cell.

[0007]

According to the first aspect of the present invention,
An electrode catalyst section is formed on both sides of the solid polymer membrane, leaving a fixed margin, and a cell configured by arranging plates on both sides of the solid polymer membrane is provided. Wherein a reinforcing metal layer is formed in the fixing margin.

According to the present invention, since the reinforcing metal layer is formed in the fixing margin, the strength can be reinforced without significantly increasing the film pressure of the solid polymer film.

The invention according to a second aspect of the present invention comprises a cell comprising a catalyst section for an electrode formed on both sides of a solid polymer membrane while leaving a fixed margin, and plates disposed on both sides of the solid polymer membrane. In a fuel cell in which a plurality of these cells are stacked to form a fuel cell stack, the electrode catalyst portion is formed on substantially the entire area of both surfaces of the solid polymer film including the fixing margin. .

In the present invention, since the electrode catalyst portion is formed on substantially the entire surface of both surfaces of the solid polymer film including the fixing allowance, the strength of the fixing allowance portion is improved, and the film pressure of the solid polymer film is greatly increased. Strength reinforcement can be achieved without increasing the thickness.

[0011] The invention according to claim 3 is the invention according to claim 1 or 2.
In the above description, the electrode catalyst portion formed leaving a fixed margin is formed unevenly.

In the present invention, since the electrode catalyst portion is formed unevenly, the contact area between the fuel gas and the catalyst during power generation is increased, and the power generation performance can be improved.

According to a fourth aspect of the present invention, there is provided a cell comprising a catalyst portion for an electrode formed on both sides of a solid polymer film while leaving a fixed margin, and plates arranged on both sides of the solid polymer film. In a fuel cell in which a fuel cell stack is formed by laminating a plurality of these cells, the electrode catalyst portion is formed to be uneven.

According to the present invention, since the electrode catalyst portion is formed unevenly, the contact area between the fuel gas and the catalyst during power generation increases, and the power generation performance can be improved.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes an outer case of a fuel cell. In the outer case 1, a polymer electrolyte fuel cell stack 3 for generating electric power by reacting fuel with oxygen in the air is provided. A fuel supply system 10 and an air supply system 20 are connected to the fuel cell stack 3.

The fuel supply system 10 has a fuel supply unit 11 for a fuel cell. The fuel supply unit 11 generates hydrogen from methane, propane, methanol and the like. , A carbon monoxide converter, a carbon monoxide remover, and the like. This fuel cell fuel supply unit 11 is connected to the fuel supply side of the fuel cell stack 3 via a fuel supply pipe 12. The air supply system 20 includes an air fan 21. The air fan 21 is connected to the air supply side of the fuel cell stack 3 via an air supply pipe 22.

The polymer electrolyte fuel cell stack 3
The fuel exhaust line 30 and the air exhaust line 40 are connected to the exhaust side of the fuel cell.

As shown in FIG. 2, the fuel cell stack 3 includes a gas separator 3a, a ribbed substrate 3b, a hydrogen electrode (anode) 3c, an electrolyte 3d, an oxygen electrode (cathode) 3e, and a ribbed substrate. 3f and cell 1
00, and each cell 100 is laminated.

Then, hydrogen is supplied to a hydrogen electrode (anode) 3c as shown by an arrow X1, and oxygen is supplied to an oxygen electrode (cathode) 3e as shown by an arrow X2. As shown in FIG. And hydrogen, the electron ions flow from the hydrogen electrode 3c to the oxygen electrode 3e, and as a result, electric power is output.

In order to facilitate the flow of electron ions from the hydrogen electrode 3c to the oxygen electrode 3e, it is desirable to reduce the thickness of the electrolyte 3d.

In this embodiment, the ribbed substrate 3b corresponds to a plate, the electrolyte 3d corresponds to a solid polymer film,
The hydrogen electrode 3c and the oxygen electrode 3e correspond to an electrode catalyst portion that is thermocompression-bonded to both surfaces of the solid polymer film.

That is, as shown in FIG.
A hydrogen electrode 3c and an oxygen electrode 3e (hereinafter, a hydrogen electrode catalyst section and a hydrogen electrode catalyst section) are fixed on both sides of a hydrogen polymer electrode 3c (hereinafter, referred to as a plate) on both sides of the substrate 3b (hereinafter, referred to as a plate). (Referred to as an oxygen electrode catalyst portion). Each catalyst part is formed by kneading a catalyst such as platinum and carbon into a paste, and applying or kneading the catalyst kneaded into a paste on both surfaces of the solid polymer film 3d. Solid polymer membrane 3
The thickness of d is about 10 to 20 microns, and the thickness of each of the catalyst parts 3c and 3e is about 10 to 20 microns.

A packing (not shown) is addressed to the fixing margin 51 when the cells 100 are stacked. In this embodiment,
As shown in FIG. 5, for the membrane reinforcement, a fixing margin 51 on both sides of the solid polymer membrane 3d has a thickness of about 10 to 20 μm, which is about the same as the thickness of the catalyst parts 3c and 3e. A metal layer 53 is formed.

The metal layer 53 is made of an inexpensive metal material (for example, a stainless metal) which has excellent conductivity, is several times stronger than the solid polymer film 3d, and is inexpensive. This metal material is formed on the fixed margin 51 on both surfaces of the solid polymer film 3d by a method such as electroless plating, thermal spraying, or deposition. The metal layer 53 is formed of the solid polymer film 3d.
Instead of being formed on the fixed margins 51 on both sides, it may be formed on the fixed margin 51 on one side.

According to this, even if the thickness is about 10 to 20 microns, the material strength of the metal layer 53 is high, so that sufficient film strength can be maintained.

FIG. 6 shows another embodiment.

In this embodiment, electrode catalyst portions 3c and 3e having a thickness of about 10 to 20 microns are formed on substantially the entire surface of both surfaces of the solid polymer film 3d including the fixing margin 51. According to this, since the strength of the portion of the fixing margin 51 is improved as compared with the related art, the strength of the solid polymer film 3d can be enhanced correspondingly.

FIGS. 7 to 9 show another embodiment.

In this embodiment, the catalyst portions 3c and 3e formed in portions other than the fixed allowance 51 are formed unevenly. In FIG. 7, the catalyst portions 3c and 3e are formed in a comb shape, and in FIG. 8, the catalyst portions 3c and 3e are formed in a spherical shape. In any case, since the catalyst portions 3c and 3e are formed unevenly, the contact area between the fuel gas and the catalyst during power generation increases, and the power generation performance can be improved. In the embodiment shown in FIG. 9, the reinforcing metal layer 53 formed on the fixing allowance 51 is formed using an inexpensive metal material as compared with the embodiment shown in FIG.

Although the present invention has been described based on one embodiment, it is apparent that the present invention is not limited to this.

[0032]

According to the first aspect of the present invention, since the reinforcing metal layer is formed in the fixing margin, the strength can be reinforced without increasing the film pressure of the solid polymer film.

According to the second aspect of the present invention, since the catalyst portion for the electrode is formed in substantially the entire area on both sides of the solid polymer film including the fixing allowance, the strength of the fixing allowance portion is improved, and the solid polymer film is formed. Strength reinforcement can be achieved without increasing the pressure.

In the third aspect of the present invention, since the electrode catalyst portion is formed unevenly, the contact area between the fuel gas and the catalyst during power generation increases, and the power generation performance can be improved.

According to the fourth aspect of the present invention, since the electrode catalyst portion is formed unevenly, the contact area between the fuel gas and the catalyst during power generation increases, and the power generation performance can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a fuel cell according to the present invention.

FIG. 2 is a schematic configuration diagram of a fuel cell stack.

FIG. 3 is a diagram illustrating the principle of a fuel cell.

FIG. 4 is a plan view of a solid polymer film.

FIG. 5 is a side view of a solid polymer film.

FIG. 6 is a diagram corresponding to FIG. 5, showing another embodiment.

FIG. 7 is a diagram corresponding to FIG. 5, showing another embodiment.

FIG. 8 is a diagram corresponding to FIG. 5, showing another embodiment.

FIG. 9 is a diagram corresponding to FIG. 5, showing another embodiment.

[Description of Signs] 3 Fuel cell stack 3b Substrate (plate) with ribs 3c, 3e Catalyst part for electrode 3d Electrolyte (solid polymer membrane) 51 Stationary allowance 53 Metal layer 100 Cell

Claims (4)

[Claims] An electrode catalyst section is formed on both sides of a solid polymer membrane while leaving a fixed margin, and a cell is formed by arranging a plate on both sides of the solid polymer membrane. A fuel cell comprising a fuel cell stack, wherein a reinforcing metal layer is formed in the fixing margin. 2. A cell comprising an electrode catalyst section formed on both sides of a solid polymer film while leaving a fixed margin, and a cell configured by disposing plates on both sides of the solid polymer film. A fuel cell comprising a fuel cell stack, wherein the electrode catalyst section is formed in substantially the entire area of both surfaces of the solid polymer film including the fixing margin. 3. The electrode catalyst part formed leaving the fixed margin is formed unevenly.
Or the fuel cell according to 2. 4. An electrode catalyst section is formed on both sides of a solid polymer membrane, leaving a fixed margin, and a cell constituted by arranging plates on both sides of the solid polymer membrane is provided. A fuel cell comprising a fuel cell stack as described above, wherein the electrode catalyst portion is formed unevenly.