JPS61206176A - Fuel cell - Google Patents

Abstract

PURPOSE:To prevent displacement caused by a horizontal load such as earthquake by installing holes in each separator and mounting pins to form a stacked structure. CONSTITUTION:A cathode electrode (air electrode) 2 on the upper side of an electrolyte retaining plate 1 and an anode electrode (fuel electrode) 3 on its lower side are placed between separator 4 and they are stacked to assemble a stacked cell. Grooves which cross at right angle each other are installed on the upper and lower surfaces of the separator 4, and grooves on the upper surface form air passage 5 and grooves on the lower surface form fuel passages. Holes 8 are installed diagonally in the separator 4 and pins 9 are inserted into the holes for stacking. A wet sealing part 14 is formed in the circumference of the electrolyte retaining plate 1 to prevent the movement of electrolyte, caused by pressure difference, which is retained by surface tension in the pores of the electrolyte retaining plate 1 and also prevent gas leakage.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fuel cell, and particularly to an electrolyte seal structure suitable for improving electrolyte retention and a structure that prevents separators from shifting due to lateral loads.

[Background of the invention]

In conventional fuel cells, as a method for preventing positional shift during cell stacking, as shown in Japanese Patent Application Laid-Open No. 59-75567, a seal packing is double interposed between the cell stack and the manifold. Some manifolds maintain airtightness by providing recesses or protrusions to prevent misalignment, but this structure has two sealing pads interposed, making it difficult to maintain structural integrity. However, it was complicated and the workability of the packing was poor.

[Purpose of the invention]

The purpose of the present invention is to prevent gas leakage from the outer peripheral end face by using a wet seal of the electrolyte plate, thereby prolonging the service life, and to prevent shifting due to horizontal loads such as earthquakes during cell stacking. [Summary of the Invention] The electrolyte of a fuel cell is held in the pores of an electrolyte holding plate using the surface tension of the electrolyte. Therefore, when a pressure difference occurs, the electrolyte flows out and the battery performance deteriorates. Furthermore, by increasing the reactant gas pressure, the fuel cell has higher power generation efficiency, and the gas flow path area can also be reduced, making it easier to downsize. When fuel cells are stacked, misalignment of separators affects the flow in the vertical direction.

The present invention is characterized in that each separator is provided with a hole, and an electrically insulating pin is attached to the hole to form a laminated structure.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples in which the structure of the present invention is applied to a molten carbonate fuel cell will be described below with reference to the accompanying drawings.

FIG. 1 shows a part of a battery stack using the structure of the present invention.

A cathode electrode (air electrode) 2 is provided on the upper surface of the electrolyte holding plate 1, and an anode electrode (fuel electrode) 3 is provided on the lower surface. That 2
A stacked battery is constructed by sandwiching two separators 4 and stacking them.

The separator 4 has perpendicular grooves on its upper and lower surfaces, the grooves on the upper surface forming air passages 5 and the grooves on the lower surface forming fuel passages 6. In addition, the separator 4 has, diagonally,
Providing the pin 68 has the effect of preventing positional displacement during stacking.

The outer peripheral end surface of the electrolyte holding plate 1 forming the gas flow passages 5 and 6 of the separator 4 is structured to prevent gas leakage by a wet seal 14, which has the effect of measuring airtightness.

FIG. 2 is a sectional view of a structural embodiment of the present invention.

A feature of the present invention is that by providing a wet seal portion 14 on the outer peripheral end surface of the electrolyte holding plate 1, movement of the electrolyte held by surface tension in the pores of the porous electrolyte holding plate 1 due to the pressure difference is prevented. , the electrolyte holding power of the electrolyte holding plate 1 is improved, and the high performance and long life of the fuel cell becomes possible.

Further, the bottle 9 sandwiched between the upper and lower separators 4 needs to have electrical insulation properties, and also needs to have heat resistance and corrosion resistance since the battery operating temperature is high and in a corrosive atmosphere. Such a member is made of ceramic alumina material. Also.

The electrolyte holding plate 1 is designed to be set inside the pin 9. Furthermore, it is desirable to improve the mutual density of the battery components (separator 4, electrodes 2, 3, electrolyte holding plate 1) to reduce internal resistance and increase battery efficiency. Furthermore, in order to maintain these conditions, it is necessary to consider a structure that will not cause lateral slippage in the event of an earthquake force. A pin 9 is inserted into a pin 68 between two separators 4 to stack them. This method is repeated to increase the height.

FIG. 3 is a cross-sectional view of a structural embodiment of the present invention.

A feature of the present invention is that holes 15 are provided in the vicinity of the outer peripheral end surface of the electrolyte holding plate 1 for pins to pass through during stacking.

By providing the through holes 15, the shape of the separator 4 can be made more compact. The through hole 15 is provided with a certain distance from the pin 9. By setting the nine through holes in consideration of the movement of the electrolyte holding plate during an earthquake, cracking of the electrolyte holding plate 1 can be prevented.

Furthermore, in the future, it will be effective as an earthquake-resistant structure related to lamination technology.

FIG. 4 is a sectional view of an embodiment of the laminated structure of the present invention. A feature of the present invention is that the device has a structure in which pins 9 are arranged on the outside of the electrolyte holding plate 1 shown in FIG.
By using the laminated support 7 instead of the pin 9, the structure has better earthquake resistance than the pin 9 structure.

The rest of the structure is a laminate of the structure shown in FIG.

The fifth tooth shows a schematic diagram of a laminated embodiment of the structure of the present invention (FIG. 1).

In this embodiment, the structures shown in FIG. 1 are stacked. Separator 4 is laminated.

There is an upper tightening plate 10 on its upper surface, and a lower tightening plate 13 on its lower surface. To the tightening plates 10 and 13.

A stacked battery is constructed by passing the bolt 12 through and tightening the nut 11. In such a shape, uniform gas flow has the effect of increasing battery efficiency.

〔Effect of the invention〕

According to the present invention, leakage from the outer peripheral end face can be prevented by using the wet seal portion of the electrolyte retaining plate, thereby providing a fuel cell with improved performance and long life.

Furthermore, since the structure is such that the separators are prevented from shifting relative to each other during cell stacking, the gas flow in the vertical and horizontal directions can be made uniform. From these points, it is possible to stabilize the gas flow and prevent leakage from the outer peripheral end surface of the electrolyte holding plate, which will have a great effect on increasing the size of cells and establishing stacking technology in the future.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of an embodiment of the structure of the present invention, Fig. 2 is a cross-sectional view of an embodiment of the structure of the present invention, Fig. 3 is a sectional view of an embodiment of the structure of the present invention, and Fig. 4 is a schematic diagram of an embodiment of the structure of the present invention. A cross-sectional view of a laminated structure example,
FIG. 5 is a schematic diagram of the laminated state of the structure of the present invention. 1... Electrolyte holding plate, 2... Cathode, 3... 7
node, 4... separator, 5... fuel flow path, 6...
...Air flow path. 13... Lower tightening plate, 14... Wet seal part.

Claims (1)

[Claims] 1. On the upper and lower surfaces of a porous electrolyte plate, there are electrodes that are porous and have good diffusion of reactive gases, and the electrolyte holding plate and both electrodes are sandwiched between separators from above and below, and a reactive gas flow path is created between the separators and the electrodes. What is claimed is: 1. A fuel cell having a structure in which each separator has a hole, and a pin having electrical insulation properties is attached to the hole to form a laminated structure.