JPS62110261A - Fuel cell - Google Patents

Abstract

PURPOSE:To make it easy to transport gas expansion electrodes and to handle them in the installation work, by forming a gas flow route converting at react either the width or the depth thereof in a desirable form. CONSTITUTION:At a gas flow passage 1a for a flue gas or air of gas expansion electrodes 1 and 2, a part of the thickness t of the flat plate portion 1b of the electrode 1 or 2 is projected into plural projections of thickness t1. In this case, neighboring passages 1a on both sides shall not be made in a similar projection in the same position. In such a way, the projections furnished at the gas flow passages 1a of the gas expansion electrodes 1 and 2 act each other to improve the bending strength in the direction parallel to the gas flow passages 1a, making it easy to transport the gas expansion electrodes 1 and 2, and to handle them in an installation work, as well as reducing a damage of the gas expansion electrodes 1 and 2 and improving the yield rate of them in the manufacture.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to fuel cells.

[Background of the invention]

FIG. 5 shows a conventional example of a fuel cell.

As shown in the figure, a normal fuel cell main body consists of a pair of gas diffusion electrodes 1 and 2, each having a flow path for fuel and air.
(Fuel electrode 1, air electrode 2) A plurality of unit cells are stacked together with an electrolyte layer 3 sandwiching an electrolyte layer 3 containing an electrolyte such as phosphoric acid interposed therebetween, with a separator 4 intervening to separate and supply fuel gas and air. ing.

In the fuel cell configured as described above, the fuel electrode 1 and the air electrode 2 are made of porous material such as carbon fiber in order to enhance gas diffusion and improve cell reaction. In addition, the separator 4 separates and supplies fuel gas and air into the stacked unit cells as described in 7 above, and is made of a thin, high-density graphite plate with low gas permeability and high conductivity. It's broken.

The gas diffusion electrode 1.2 has a density of 0.45 to 0.65 g to improve gas diffusion, and is also provided with over 100 grooves as gas flow passages. The bending strength in the direction parallel to the direction becomes extremely small.

By the way, it is advantageous to stack many unit cells within a limited stacking height, and the gas diffusion electrode 1.2 and separator 4 need to be thin, but in order to increase the power generation capacity of the fuel cell, the gas The area of the diffusion electrodes 1 and 2 must be increased.

By making the gas diffusion electrodes 1 and 2 thin and thick in this manner, the gas diffusion electrodes 1 and 2 have extremely weak mechanical strength against bending and impact, and are easily damaged. Therefore, there is a problem that not only the yield is poor, but also the work efficiency of transportation, assembly, etc. is degraded due to the necessity of extra arrangement. Regarding this, Japanese Patent Application Laid-Open No. 59-6097
There is Publication No. 1.

[Purpose of the invention]

The present invention was developed in view of the above points, and an object of the present invention is to provide a fuel cell in which the gas diffusion electrode can be easily transported and handled during assembly work.

[Summary of the invention]

In other words, 5 the present invention provides a fuel cell equipped with a pair of gas diffusion cells having a plurality of gas flow passages and a unit cell having a toner solution disposed between the gas diffusion electrodes. The gas diffusion electrode is formed by arbitrarily changing at least one of the width and the depth, whereby the gas diffusion electrode is formed so as to improve its mechanical strength in the direction parallel to the gas flow path. It becomes like this.

[Embodiments of the invention]

The present invention will be explained below based on the illustrated embodiments. FIG. 1 shows an embodiment of the invention. Note that parts that are the same as those in the conventional system are given the same reference numerals, and therefore their explanations will be omitted. In this example, the gas diffusion electrode l.

The depth of the gas flow passage 1a of No. 2 was arbitrarily changed. By doing this, the depth of the gas flow path 1a can be changed arbitrarily, and the gas diffusion electrode 1.2 is formed into a trap so that the mechanical strength in the direction parallel to the gas flow path 1a is improved. The gas diffusion electrode 1.
It is possible to obtain a fuel cell that can be easily handled during (2) transportation and (1) assembly work.

That is, the gas diffusion electrode 1.2 is connected to the fuel gas or air gas flow path 1a of the gas diffusion electrode 1.2. 2 flat plate part 1b
A plurality of protrusions each having a thickness of 1° are provided by protruding a portion of the thickness t. In this case, nine adjacent gas flow passages 1a
Arrange so that there are no protrusions in the same place. By doing so, the gas diffusion electrode 1.2 is connected to the gas flow path 1.
The protruding portions provided in a interact with each other, and the bending strength of the gas diffusion electrode 1.2 in the direction parallel to the gas flow path 1a is improved, making it easier to transport and assemble the gas diffusion electrode 1.2. This makes it easier to handle the gas diffusion electrodes 1 and 2, reducing damage to the gas diffusion electrodes 1 and 2 during handling.
Yield during manufacturing can be improved. Furthermore, by providing the protruding portions of the flat plate portions 1bVc and thickness t of the poles 1 and 2 for gas diffusion', the flow of the fuel gas or tI'i air flowing through the gas flow passage 13 becomes turbulent, and the gas diffusion 1tk1
．． It can be expected that the gas diffusion effect within 2 will be improved.

Furthermore, the provision of protrusions improves the compressive strength of the protrusions LC of the gas diffusion electrodes 1 and 2, making it possible to increase the clamping pressure when stacking unit cells together. Thus, the contact resistance between the stacked unit cells can be reduced. Therefore, loss due to resistance during battery power generation is reduced, and power generation efficiency can be improved.

Another embodiment of the invention is shown in FIG.

In this embodiment, the width of a part of the protrusion IC of the gas diffusion electrode 1.2 is increased, and the gas diffusion electrode 1.2 is provided in the gas flow passage 1a.
．． The thickness 1.2 is obtained by projecting a part of the thickness t of the flat plate portion 1b of No.2.
Multiple protrusions were provided.

By doing so, the mechanical strength of the gas diffusion electrode 1.2 is improved, and the same effect as in the case described above can be achieved.

FIG. 3 shows yet another embodiment of the invention. In this embodiment, the gas flow passages are arranged at equal intervals.

Since the gas flow passage 1d is provided with a narrower width than the other gas flow passages, the mechanical strength of the gas diffusion electrode 1.2 is improved in this case as well, and the same effects as in the above case can be achieved.

FIG. 4 shows yet another embodiment of the invention. In this embodiment, a gas flow passage 1e having a smaller depth than the other gas flow passages is provided among the gas flow passages provided at equal intervals. In this case as well, gas diffusion 11. The mechanical strength of Ul, 2 is improved, and the same effects as in the case described above can be achieved.

〔Effect of the invention〕

As described above, the present invention provides a fuel cell in which the gas diffusion electrode can be easily handled during the transportation and assembly operations, and the gas expansion #kt electrode can be easily handled during the transportation and assembly operations. be able to.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a gas diffusion electrode of an embodiment of the fuel cell of the present invention, and FIGS. 2 to 4 show gas flow passages of the gas diffusion electrode of different embodiments of the fuel cell of the present invention. 5 is a perspective view showing the basic structure of a conventional fuel cell. 1... Gas diffusion electrode (fuel electrode), 1a... Gas flow path. 1b... Gas diffusion 1: flat plate part of the pole, 1c... Projected part of the gas diffusion electrode, ld, le... Gas flow path, 2...
・Gas diffusion electrode (air electrode), 3... Electrolyte layer, 4...
·separator.

Claims (1)

[Claims] 1. A pair of gas diffusion electrodes having a plurality of gas flow passages;
A fuel cell comprising a unit cell having an electrolyte layer disposed between gas diffusion electrodes, wherein at least one of the width and depth of the gas flow passage is arbitrarily changed. . 2. The fuel cell according to claim 1, wherein the depth of each of the gas flow passages is changed.