JPS6132360A - Fuel cell - Google Patents

Abstract

PURPOSE:To enable a liquid electrolyte to be supplied into the matrices by packing an electrolyte-holding material into one end of each of the fuel and the air electrodes and forming an electrolyte supply path in each of the separators. CONSTITUTION:Each unit cell is formed by placing a matrix 3 between a fuel electrodes 2a and an air electrode 2b positioned in such a manner as to locate their gas flow paths 2aS and 2bS perpendicular to each other. When a fuel cell is constituted by stacking thus formed unit cells with separators 4 interposed, a cut is formed in one end of each of the fuel and the air electrodes 2a and 2b and a pasty electrolyte-holding material 6 prepared by mixing a silicon carbide powder into a liquid electrolyte is packed into the cuts. Additionally, joint pipes 7 continuous with an electrolyte container 8 are connected to the separators 4. Because of the above structure, it is possible to easily and securely supply the liquid electrolyte into the matrices 3 from their outside without any necessity of complicated formation of the electrodes 2a and 2b even when they are thin.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to the improvement of fuel cells, and in particular to fuel cells in which a matrix is interposed between the fuel electrode and the air cell, and an electrolyte is reserved in the matrix. This is for improving batteries.

[Background of the invention]

In this type of fuel cell, which has been commonly used in the past, a matrix holding an electrolyte is interposed between the electrodes, that is, between the fuel electrode and the air electrode, and a matrix holding an electrolyte is interposed between the fuel gas supplied from the outside and the air. Electricity is generated while producing water through a reaction with oxygen.

Since this reaction is accompanied by heat generation, the water produced turns into steam. As this water vapor is generated, a portion of the electrolyte in the matrix is dissolved and released to the outside together with the water vapor, gradually reducing the amount of electrolyte and shortening the battery life.

For this reason, conventional methods have been widely adopted in which electrodes are made porous from carbon fiber or the like and the pore spaces are used to reserve electrolyte. However, this method has the problem of easily inhibiting the diffusion of fuel gas and air.
Furthermore, since it is necessary to reduce the density of the entire electrode, the mechanical strength is weakened and the electrode tends to become unstable. Moreover, even if this is done, the amount of electrolyte to be reserved is still limited to a certain extent, so there is a drawback that the service life is also limited. Therefore, it is possible to replenish the stain remover from outside, but if you try to implement it, you will have to realize that the electrode thickness is as thin as 1 to 2 wrrtt, and that the pipes for replenishing the electrolyte are necessary for supplying fuel gas and air. It was difficult to replenish the electrolyte externally, as there was no good idea.

[Purpose of the invention]

The present invention was conceived with this in mind, and its purpose is to provide a flexible fuel that allows easy replenishment of electrolyte even if the electrode thickness is thin, and without special processing of the manifold. °We provide batteries.

[Summary of the invention]

That is, in the present invention, a notch is provided in at least one corner of the fuel electrode and the air electrode, and an electrolytic holding material is embedded in each notch, and a portion of the separator facing the electrolytic holding material is provided with a notch. , an electrolytic replenishment passage communicating with the outside is provided, and the matrix is supplied with electrolyte from the outside.

[Embodiments of the invention]

The present invention will be described in detail below based on the illustrated embodiments.

FIG. 1 shows an exploded perspective view of the main parts of the fuel cell, and FIG. 2 shows a side view thereof. The fuel cell includes a fuel electrode 2a and an air electrode 2b, and a manifold (not shown) is provided on the side thereof.

The fuel electrode 2a and the air electrode 2b sandwich the matrix (electrolyte holding layer) 3, and have respective gas flow paths 2aS and 2b.
The S's are arranged so that they intersect with each other. Furthermore, separators 4 are arranged on the outside (top and bottom in the figure) so as to sandwich these electrodes.

At this time, the direction in which the entrance and exit of the gas flow path is located on the side surface of the fuel electrode 2a is set so that the planar dimension (width dimension) is larger than that of the other pair of air electrodes 2b, and the length and width of the separator 4 are set respectively. Match the dimensions of this larger electrode. That is, a structure is created in which rectangular electrodes are combined so as to cross each other and the outsides are sandwiched between large separators.

As a result, gaps corresponding to the thickness of each electrode are formed at the ends of each electrode, that is, at least at the corner portions. Then, this gap is filled with an electrolyte holding material 6.

Since this electrolytic solution holding material is filled throughout the electrodes 2a and 2b, both electrolytic solution holding materials are overlapped between the separators 4 at the corners of the battery, as shown in the figure. A hole 6b of an appropriate size is bored in the corner of the separator 4 facing this corner, and the top of the hole 6b is connected to an external electrolyte tank 8.
The connecting pipe 7 is connected to the entire connecting pipe 7. The electrolyte is passed from the external electrolyte tank 8 through the connection pipe 7 through the hole in the separator 4 at the top of the battery, and then via the electrolyte holding material 6 from the end of each electrode to the IJ sock between the electrodes. If appropriate pressure is applied at the 3rd end, the electrolyte will always be replenished into the battery and will never run out.

As the dissipating liquid holding material 6, silicone carbide and powder of this composite mixed in paste form with an electrolytic solution are suitable, but the material is not limited to this.
In addition, it is also possible to fill it with fibrous materials such as carbon fiber.

In the above explanation, when forming the space in which the electrolytic holding material 6 is buried, the width of the electrode is narrowed and it is provided only on one side of the electrode, but it is not always necessary to form it in this way. For example, as shown in FIG. 3, electrolytic holding materials 6 may be placed on both sides of the electrode. In particular, when the electrolytic holding material is arranged on both sides of the electrode in this way, the electrolytic solution is replenished from both sides, and the stain remover is replenished evenly throughout, which is very good.

There are various ways to consider creating a space for embedding the electrolytic holding material 6, but the important thing is to arrange the electrolytic holding material at least at the corner of the electrode, and the simplest method is Of course, the same effect can be obtained by providing a notch in the corner of the electrode and placing the electrolytic holding material in this part.

〔Effect of the invention〕

As explained above, the present invention provides a notch in at least one corner of a fuel electrode and an air electrode, and embeds an electrolyte holding material in each of the notches, and the electrolyte holding material of a separator. Since an electrolyte replenishment passage that communicates with the outside is provided in the part facing the manifold, there is no need to provide an electrolyte replenishment passage in the manifold. Even if the electrode is thin, the electrolyte can be easily replenished without any problems.

[Brief explanation of drawings]

FIG. 1 is an exploded perspective view showing the main parts of the fuel cell of the present invention, FIG. 2 is a side view seen from the direction of arrow Q in FIG. 1, and FIG. 3 is an exploded perspective view showing another embodiment of the present invention. Figure 1. 1... Manifold, 2a... Fuel electrode, 2b...
- Air electrode, -3: Matrix, 4 Separator, 6 Electrolyte holding material, 8 External electrolyte tank.

Claims (1)

[Claims] 1. A fuel electrode having a gas flow path, an air electrode overlaid on the fuel electrode and having an air flow path, and a matrix interposed between the air electrode and the fuel electrode. Equipped with
In a fuel cell in which a plurality of unit cells are stacked with separators interposed therebetween, and a manifold for supplying and discharging fuel gas and air is disposed on the side of the stacked cells, the fuel A cutout is provided in at least one corner of the electrode and the air electrode, and an electrolyte holding material is embedded in each cutout, and an external A fuel cell characterized by having an electrolyte replenishment passage communicating with the fuel cell. 2. The fuel cell according to claim 1, wherein the electrolyte holding material is made of a porous material. 3. The fuel cell according to claim 2, wherein the porous material is formed by mixing a fibrous material and an inorganic powder.