JPH07123048B2 - Fuel cell - Google Patents

Description

Description: TECHNICAL FIELD OF THE INVENTION The present invention is intended to surely prevent gas leakage and liquid leakage from a side portion of a battery cell in a fuel cell in which battery cells are stacked in multiple stages via separators. It relates to a fuel cell.

[Prior art]

Fuel cells have a structure in which multiple layers of battery cells are formed by sandwiching an electrolyte layer such as an electrolyte matrix impregnated with an electrolyte solution such as phosphoric acid between a positive electrode plate and a negative electrode plate, and hydrogen is supplied to the negative electrode plate side of each battery cell. At the same time, air (oxygen) is supplied to the positive electrode plate side to cause both to react with each other to generate water and electric energy. When the battery cells are stacked in multiple stages as described above, a gasket for sealing is arranged around the battery cells to prevent the electrolytic solution, gas such as air and hydrogen from leaking from the side edges.

However, in a conventional fuel cell, when a stack of battery cells stacked in multiple stages is tightened from above and below, the gasket tends to slip laterally in the plane direction and escape, and the escape of this gasket has a sealing effect against electrolyte and gas leakage. There was a shortcoming that it would be insufficient.

[Object of the Invention]

An object of the present invention is to provide a fuel cell capable of reliably sealing electrolyte and gas leaking from the side edges of battery cells.

[Structure of Invention]

The present invention to achieve the above object, a gasket for sealing is arranged around a battery cell constituted by sandwiching an electrolyte layer between a positive electrode plate and a negative electrode plate, and a plurality of these battery cells are laminated in multiple stages with a separator interposed. In the fuel cell, the mating surface between the gasket and the separator is provided with a convex portion on one surface and a concave portion on the other surface, and the convex portion and the concave portion are in the same plane as the mating surface. Continuously extending on both side edges parallel to the existing gas passage in a direction parallel to the gas passage, while fitting the convex portion and the concave portion to each other, the peripheral portion of the electrolyte layer and the positive electrode plate It is characterized in that the negative electrode plate is retracted inwardly from the peripheral edge portion, the convex portion provided on the inner peripheral surface of the gasket is inserted and fitted into the recessed concave portion, and integrally tightened and fixed in this state. is there.

〔Example〕

In FIG. 1, reference numeral 1 denotes a battery cell, which is formed by sandwiching an electrolyte layer 4 composed of a plate-shaped electrolyte matrix impregnated with an electrolytic solution such as phosphoric acid between a positive electrode plate 2 and a negative electrode plate 3. There is. A gasket 9 made of a material having excellent heat resistance and corrosion resistance, such as tetrafluoroethylene or fluorine rubber, is arranged around the battery cell 1 and a plurality of battery cells 1 are separated in this state. 5 are stacked in multiple stages. The gasket 9 is designed to spread in the surface direction when the laminated body is clamped and fixed, and is a surface formed by abutting the upper and lower surfaces of the inner peripheral side protruding portion with the upper surface of the positive electrode plate 2 and the lower surface of the negative electrode plate 3. The positive seal plate 2 side and the negative electrode plate 3 side are hermetically sealed by the directional seal portion.

Further, current collector plates 6 and 6 are arranged at both ends of the laminated body 10, and end plates 8 and 8 are applied to the outside of the laminate 10 via insulating plates 7 and 7 made of polytetrafluoroethylene, fluorine rubber, or the like. ,
In that state, the fuel cell body is constituted by integrally fastening and fixing with a fastening tool (not shown). The collector plate 6 is provided with a collector terminal 6a for taking out electricity, and the collector terminal 6a penetrates through the holes 7a, 8a provided in the insulating plate 7 and the end plate 8 at the time of tightening and solidifying to the outside. It is projected.

The separator 5 has a large number of guide grooves (gas passages) 5a, ... 5a on the side facing the positive electrode plate 2, and a large number of guide grooves 5b, ... 5b on the side facing the negative electrode plate 3. , Both guide grooves 5a and 5
b and the relationship are orthogonal to each other. However, among these separators, the outermost separator has a guide groove 5a or 5b on only one surface, and the separators arranged at several points on the way have a passage through which a cooling fluid such as water or air flows in the middle part. It is configured with 12.

Further, the separator 5 has concave grooves 10a, 10a continuously extending in a direction parallel to the guide groove 5a on both side edges of the surface on the side where the guide groove 5a is present and parallel to the guide groove 5a. , Guide groove 5 again
On the opposite side surface where the guide groove 5b having a relationship orthogonal to a exists and parallel to the guide groove 5b, the concave grooves 10b and 10b continuously extended in the direction parallel to the guide groove 5b are also formed. have.
On the other hand, the gasket 9 includes the concave grooves 10a, 10 of the separator 5 described above.
The ridges 11a and 11a are formed on the portions facing the a, and the ridges 11b and 11b are formed on the portions of the separator 5 facing the concave grooves 10b and 10b. These groove 10a, ridge 11a and groove 10b
The ridges 11b and the ridges 11b are fitted to each other when the battery cell stack is clamped and fixed, thereby preventing the gasket from slipping laterally in both the lateral direction and the front-back direction.

In addition, the peripheral portions of the positive electrode plate 2, the negative electrode plate 3, and the electrolyte layer 4 are recessed in such a manner that the side edges of the electrolyte layer 4 are recessed inward from the peripheral portions of the positive electrode plate 2 and the negative electrode plate 3 on both sides. With respect to this recessed recess, a protrusion 9a provided on the inner peripheral surface of the gasket 9
Are inserted and fitted. By thus inserting the convex portion 9a of the gasket 9 into the concave portion between the positive electrode plate 2 and the negative electrode plate 3, not only the gas leak seal is made more reliable but also the electrolyte layer 4 is tightened more than necessary. By doing so, damage is prevented.

The ridges 11a, 11a and the recessed grooves 10a, 10a described above have ridges 11a, 11b on the side of the separator 5 as in the embodiment shown in FIG.
You may make it provide the recessed groove 10a, 10b in the gasket 9 side. Further, the convex and concave shapes of the convex stripes and the concave grooves are not limited to the above-mentioned circles and squares, and may be any other shape such as an oval or a triangle.

Oxygen (air) is supplied to the guide grooves 5a and 5b of the separator 5 facing the positive electrode plate 2 side, and hydrogen is supplied to the guide groove 5b facing the negative electrode plate 3. . The gas supplied to each is decomposed by the electrolytic solution of the electrolyte layer 4, oxygen takes out electrons from the positive electrode plate 2 to become oxygen ions, and hydrogen releases electrons to the negative electrode plate 3 to become hydrogen ions. Both ions combine to form water, and water and electric energy are generated by this reaction.

Now, in the above-mentioned fuel cell, the gasket 9 and the separator 5 are continuously joined to the mating surface and to the both side edges of the guide grooves 5a and 5b existing in the same plane as the mating surface, and are fitted to each other. It has convex ridges 11a and 11b and concave grooves 10a and 10b which are in contact with each other, and by positively engaging them, lateral displacement of the gasket 9 in the surface direction is prevented. Therefore, the gasket 9 maintains a predetermined position to reliably seal gas leakage of the electrolytic solution, air, hydrogen and the like.

In addition, by inserting and fitting the convex portion 9a protruding from the inner peripheral surface of the gasket 9 into the concave portion in which the side end of the electrolyte layer 4 is recessed inward from the peripheral portions of the positive electrode plate 2 and the negative electrode plate 3, gas leakage is caused. The seal is made more reliable and the electrolyte layer 4 is prevented from being damaged due to excessive tightening pressure.

〔The invention's effect〕

As described above, in the fuel cell of the present invention, a gasket for sealing is arranged around a battery cell constituted by sandwiching an electrolyte layer between a positive electrode plate and a negative electrode plate, and a plurality of these battery cells are interposed with a separator. In a multi-layered fuel cell stack, a mating surface between the gasket and the separator is provided with a convex portion on one surface and a concave portion on the other surface,
Further, the convex portion and the concave portion are continuously extended in both side edges parallel to the gas passage existing in the same plane as the mating surface in a direction parallel to the gas passage, and the convex portion and the concave portion are mutually formed. By fitting, the gasket maintains a predetermined position and surely seals gas leakage of electrolyte, air, hydrogen, etc., and the side edges of the electrolyte layer are further inside than the peripheral portions of the positive electrode plate and the negative electrode plate. Since the convex portion provided on the inner peripheral surface of the gasket was inserted and fitted into the recessed concave portion,
The gas leak seal should be made more reliable, and the electrolyte layer should be prevented from being damaged due to excessive tightening pressure.

[Brief description of drawings]

FIG. 1 is a perspective view showing a fuel cell having a sealing structure according to an embodiment of the present invention in an exploded state before the members are fastened together and solidified, and FIG. 2 is a side edge of a battery cell in the fuel cell. Sectional drawing which shows the sealing structure of a part in the state before tightening, FIG. 3 is sectional drawing which shows the other embodiment of the same sealing structure. 1 ... Battery cell, 2 ... Positive electrode plate, 3 ... Negative electrode plate, 4 ...
Electrolyte layer, 5 ... Separator, 5a, 5b ... Guide groove, 9 ...
... Gasket, 9a ... projection, 10a, 10b ... recessed groove (recess), 11a, 11b ... projection (projection).

Claims (1)

[Claims] 1. A fuel cell in which a gasket for sealing is arranged around a battery cell constituted by sandwiching an electrolyte layer between a positive electrode plate and a negative electrode plate, and a plurality of these battery cells are laminated in multiple stages with a separator interposed. A gas passage in which a convex portion is provided on one surface and a concave portion is provided on the other surface between the gasket and the separator, and the convex portion and the concave portion are present in the same plane as the mating surface. Are continuously extended on both side edges parallel to the gas passage in a direction parallel to the gas passage, and the convex portion and the concave portion are fitted to each other, while the peripheral edge portion of the electrolyte layer is the peripheral edge portion of the positive electrode plate and the negative electrode plate. The fuel cell is characterized in that it is retracted inward from the portion, the convex portion provided on the inner peripheral surface of the gasket is inserted and fitted into the recessed concave portion, and in this state, the convex portion is integrally tightened and fixed.