JPS62165874A - Fuel cell stack - Google Patents

Abstract

PURPOSE:To enable a cell to laminate intensively and besides obtain the high performance and long life of the cell by dividing the stack in a container into minor stacks, tightening the minor stacks in each at a predetermined facial pressure and at the same time supporting them so that the self-weight of each minor stack may not effect on the other minor stacks. CONSTITUTION:A laminated cell 1 laminating multiple unit cells, each of which is composed of an anode and a cathode facing each other interposing an electrolytic plate between themselves, is tightened by two cell tightening plates 2 arranged at the top and bottom of the cell and four tightening bolts 3 at a predetermined facial pressure, using tightening springs 4 and tightening nuts 5 and these form a minor stack 6. The tightening springs 4 act as to lessen the change of the tightening facial pressure of the laminated cell 1 owing to the height change caused by the thermal deformation of the minor stack 6. The multiple, for example three, minor stacks 6 formed in such a way are laminated in the direction of the height in such a condition that the self-weight of each minor stack is supported by three minor stack supporting plates 7 and four supporting bolts 8 using supporting nut 9 and form a cell stack 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a fuel cell stack, and relates to a fuel cell stack having a structure suitable for stacking up to 1%.

[Background of the invention]

Conventional fuel cell stack structures include, for example, Japanese Patent Application Laid-Open No. 58-115772 and Japanese Patent Application Laid-open No. 58-16416.
As described in No. 8, there is a structure in which the stack is divided into small blocks and each small block is tightened and laminated, and a liquid-tight container that communicates with each other between the intermediate plate and end plate of the small block and the small block. The sandwiched structure is known.

However, in conventional fuel cell stacks with such a structure, the surface pressure when tightening the cells cannot be set to less than the surface pressure due to the stack's own weight.
When cells are stacked, there is a problem in that the surface pressure of the cells near the bottom becomes too high, resulting in performance deterioration due to cracking of the solute and compression creep of the electrodes.

[Purpose of the invention]

An object of the present invention is to provide a fuel cell stack having a structure in which surface pressure can be uniformly set to an appropriate value when tightening the cells in order to improve the performance and extend the life of the cells.

[Summary of the invention]

In the present invention, when stacking a single fuel tank to a high degree, if the unit cells are stacked as they are, the surface pressure for tightening the cells at the bottom of the stack will be too high due to the weight of the cells, so the stack is divided into multiple small stacks. By dividing the stack, supporting the stack so that the weight of each small stack does not apply to other small stacks, and tightening each small stack independently,
This fuel cell stack has a structure that reduces the influence of surface pressure due to the weight of the cells, and allows the surface pressure to be set evenly to an appropriate value when tightening the cells.

[Embodiments of the invention]

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a side view showing a first embodiment of a fuel cell stack according to the present invention. In FIG.

1 is a stacked battery, 2 is a plate for battery tightening, 3 is a bolt for battery tightening, 4 is a battery tightening spring, 5 is a nut for battery tightening, 6 is a small stack, 7 is a small stack support plate, 8 is a small Stack support bolt, 9 is a small stack support nut, 10 is a stack support stand, 11 is a battery container.

12 is a battery container 7, and 13 is a battery container support stand.

14 is a battery stack.

'Flip!' in Figure 1! A stacked battery 1 is made by stacking a plurality of unit batteries consisting of an anode and a cathode sandwiched between lubricant plates and facing each other with a separator having a gas flow path in between. The second and fourth bolts are tightened to a predetermined surface pressure using bolts 3, springs 4, and nuts 5 to form a small stack 6. Note that the tightening spring 4 here functions to alleviate changes in surface pressure due to tightening of the laminated battery 1 due to changes in height due to thermal deformation of the small stack 6 or the like.

A plurality of small stacks 6, for example, three small stacks 6 formed in this way are supported by three small stack support plates 7 and four support bolts 8, respectively, and are moved in the height direction using support nuts for 9 minutes. The battery stack 14 is constructed by being stacked and housed in a battery container 11 having a battery container 7 flange 12 and a battery container support 13 while being supported by a stack support 10 .

According to this embodiment, the number of laminated batteries l in each small stack 6 that divides the battery stack 14 into a plurality of pieces is not too large, and the dead weight of other small stacks 6 is not added to each small stack 6. Therefore, the surface pressure of the stacked battery 1 can be set to an appropriate value, and cracking of the electrolyte plate and creep of the electrodes of the stacked battery 1 can be prevented, and higher performance and longer life of the fuel cell can be achieved. In addition, by dividing the TA mistack 1 into small stacks 6, it becomes easier to follow height changes due to thermal deformation of the laminated battery 1, simplifying the tightening structure. The size of the battery is also small, making it stable and easy to assemble. Also, in the event of a failure, the other small stacks 6 can be tightened and the failed small stack 6 can be replaced without changing the surface pressure, making maintenance management easy. .

FIG. 2 is a side view showing a second embodiment of the fuel cell stack according to the present invention. The battery stack 14 in FIG. 2 omits the small stack support plate 7, support bolts 8, and support nuts 9 in FIG. Bolt 3 extends to the long bolt common to stack 1, and the battery tightening made of this long bolt is bolt 3.
However, each battery is tightened together with the plate 2 and the tightening spring 4, and the tightening nut 5 serves both to tighten the laminated battery 1 of each small stack 6 and to support its own weight, and moreover, each small stack 6
The structure is such that its own weight is not added to other small stacks 6.

According to this embodiment, in addition to the plate 2 for battery tightening and the bolt 3 for battery tightening, the stack support plate 7 and stack support bolt 8 shown in FIG. 1 are not required, so the number of required parts is reduced. The structure can be simplified.

FIG. 3 is a side view showing the J3 embodiment of the fuel cell stack according to the present invention. The battery stack 14 in FIG. 3 omits the small stack support bolt 8, support nut 9, and stack support stand 1o in FIG. The support plate 7 is extended, and the small stack support plate 7 and battery container 11 support the weight of each stack 6, and the weight of each small stack 6 is not added to other small stacks 6.

According to this embodiment, since the battery container 11 is divided into each small stack 6, when a gas leak occurs, it is easy to determine which small stack 6 is the cause of the gas leak. The influence of other small stacks 6
In addition, the temperature distribution in the height direction inside the battery container 11 is made uniform, which helps improve battery performance.

〔Effect of the invention〕

Therefore, it is possible to make batteries highly laminated, and to achieve higher performance and longer life.In addition, since the number of stacked batteries to be tightened is small, assembly and maintenance inspection are also facilitated.

[Brief explanation of drawings]

The first panel is a side view showing a first embodiment of the fuel cell stack according to the present invention, FIG. 2 is a side view showing the second embodiment, and FIG. 3 is a side view showing the third embodiment. It is. 1...Stacked battery, 2...Battery tightening plate, 3...Battery tightening bolt, 4...Battery tightening spring, 5...Battery tightening nut, 6...Small Stack, 7...Small stack support plate. 8... Small stack support bolt, 9... Small stack support nut, 10... Stack support base, 11... Battery container. Pre-30

Claims (1)

[Claims] 1. In a fuel cell stack in which a stack consisting of a plurality of unit cells, each consisting of an anode and a cathode facing each other with an electrolyte plate sandwiched therebetween, is laminated with a separator having a gas flow path in between, the stack in the container is housed. A fuel cell stack that is divided into at least two or more small stacks, tightened to a predetermined surface pressure for each small stack, and supported so that the weight of each small stack does not act on other small stacks. .