JP3072034B2 - Fuel cell separator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a structure of a separator used in a molten carbonate fuel cell.

[0002]

2. Description of the Related Art Molten carbonate fuel cells have features not found in conventional power generators, such as high efficiency and low environmental impact, and have attracted attention as power generation systems following hydro, thermal and nuclear power. Currently, intensive research is underway.

[0003] Since a molten carbonate fuel cell has a low voltage (about 0.8 V) in a single cell, a battery stacked in multiple stages via a separator (bipolar plate) is practically used. This stacked battery is called a stack. FIG. 3 shows a configuration of the laminated battery. 1 indicates a single cell. The unit cell 1 is provided with an electrolyte plate 2 at the center, a cathode 3 (air electrode) on one surface, an anode 4 (fuel electrode) on the other surface, and a separator 5.
Thus, a cathode gas 6 containing oxygen is supplied to the cathode 3 and an anode gas 7 containing hydrogen is supplied to the anode 4. Considering this with the separator 5 as the center, the cathode 3 is provided on one surface, the anode 4 is provided on the other surface, the cathode gas 6 is separated from the cathode 3, and the anode gas 7 is separated from the anode 4. Supply.

[0004] Since the stack is formed by stacking the separators 5 in multiple stages with the electrolyte plate 2 interposed therebetween, the separators 5 occupy a large part of the production cost of the molten carbonate fuel cell. When a large number of separators 5 are manufactured, a press forming method having a thin plate structure is most promising for cost reduction. The separator 5 schematically shown in FIG. 3 is an image produced by shaving out by machining, but when it is formed by pressing, a single plate (this is called a center plate) is corrugated by pressing. And a passage for the cathode gas 6 and the anode gas 7 is provided.

[0005]

In the fuel cell separator 5, both the cathode 3 and the anode 4 and the electrolyte plate 2 are provided.
There is a role to hold. Since the electrodes 3 and 4 and the electrolyte plate 2 are very brittle as compared with metal, if the separator 5 is deformed, the electrodes 3 and 4 and the electrolyte plate 2 may be cracked during assembly. In the case where the center plate, which is a main member of the separator 5, is pressed, the load per unit area is considerably large, so that there is a large possibility that deformation will occur as a whole. For this reason, under the present circumstances, in many cases, heat treatment is performed after pressing the separator 5 to remove the deformation, and thus, there is a problem that the cost is increased and the working time is increased.

The present invention has been made in view of the above problems, and has as its object to suppress deformation of a separator formed by pressing.

[0007]

In order to achieve the above object, according to the first aspect of the present invention, a center plate for separating an anode gas and a cathode gas, and a center electrode having substantially the same external dimensions as the center plate and having a central electrode. Two mask plates having openings and provided in parallel at a predetermined interval with the center plate interposed therebetween and closely attached to the center plate at the outer peripheral end, and the openings for the electrodes in contact with and in parallel with the inner surface of the mask plate. And a punch plate provided so as to cover the center plate, and the center plate is corrugated around an outer peripheral end of the mask plate having a predetermined interval.

By providing a corrugated shape along the outer periphery of the center plate, the rigidity of the periphery is increased and deformation can be prevented.

According to the second aspect of the present invention, the vertical interval between the waveforms is a dimension that fits into the predetermined interval of the mask plate. This allows the center plate to be held around by the mask plate, thereby suppressing deformation.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view showing an embodiment of a separator, partially showing a surface through which a cathode gas flows. In this drawing, components having the same functions as those in FIG. 3 are denoted by the same reference numerals. FIG. 2 shows an AA section, a BB section, and a CC section of FIG. The separator 5 has a substantially square shape, and a central opening is formed in the battery area 10 by the cathode 3 or the anode 4.
Is provided. FIG. 1 shows the surface of the cathode 3 and it is assumed that the lower surface is the anode 4, but the reverse is also possible.
A cathode gas opening 11 for supplying the cathode gas 6 and an anode gas opening 12 for supplying the anode gas 7 are provided on the lower side of the battery region 10, and the upper side is passed through the cathode 3 to perform a battery reaction and discharged. A cathode exhaust gas opening 13 for collecting the cathode exhaust gas 8 and a cathode exhaust gas opening 14 for collecting the anode exhaust gas 9 that has passed through the anode 4 to perform a battery reaction and have been discharged are provided.

The cathode gas passage 15 has four stages, and the gas flow is diffused in a direction perpendicular to the flow direction by slightly shifting each stage. Grooves 16 are provided around the periphery to prevent gas inside from leaking out and to prevent air from entering from outside.

In the AA cross section of FIG. 2, the center plate 20 is pressed into a corrugated shape, and two mask plates 21 are provided in parallel around the center plate 20 in the vertical direction. Punch plates 22 are provided in parallel in contact with the inner surfaces of the upper and lower mask plates 21, and the waveform of the center plate 20 is arranged between the punch plates 22 to support the punch plates 22. The cathode 3 is provided in the battery region 10 on the upper surface of the punch plate 22, and the battery region 1 on the lower surface.
At 0, an anode 4 is provided. Punch plate 2
2 functions to support the electrodes 3 and 4 and to transmit the cathode gas 6 and the anode gas 7 to the electrodes 3 and 4 through a number of openings. The cathode gas 6 flows on the cathode 3 side of the waveform of the center plate 20, and the anode gas 7 flows on the anode 4 side. The gas does not flow at the position of the waveform forming the groove 16. The cross section BB has substantially the same structure as the cross section AA.

The C-C cross section is such that the center plate 20 is provided in a waveform 23 between the upper and lower mask plates 21 over the entire circumference along the outer circumference of the separator 5. By providing the waveform 23 over the entire circumference of the center plate 20 in this manner, the rigidity of the center plate 20 increases, and overall deformation is suppressed. This waveform 23 is shown at the left end in the AA section and the BB section. Note that the waveform 23 can suppress the overall deformation of the separator 5 by fitting between the upper and lower mask plates 21. Although the shape of the waveform is sinusoidal (sine), it may be rectangular.

[0014]

As is apparent from the above description, according to the present invention, a corrugation is provided between the mask plates over the entire circumference of the center plate of the separator, so that the entire deformation caused by the press can be prevented. This eliminates the need for the deformation removal operation by heat treatment, thereby reducing the production cost and the production period of the separator.

[Brief description of the drawings]

FIG. 1 is a plan view of a separator according to an embodiment.

FIG. 2 shows an AA section, a BB section, and a CC section of FIG.

FIG. 3 is a schematic diagram of a fuel cell.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Single cell 2 Electrolyte plate 3 Cathode 4 Anode 5 Separator 6 Cathode gas 7 Anode gas 8 Cathode exhaust gas 9 Anode exhaust gas 10 Battery area 11 Cathode gas opening 12 Anode gas opening 13 Cathode exhaust gas opening 14 Anode exhaust gas opening 15 Cathode gas flow path 16 groove Reference Signs List 20 center plate 21 mask plate 22 punch plate 23 waveform

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-241870 (JP, A) JP-A-7-85880 (JP, A) JP-A-9-63598 (JP, A) JP-A-9-98 63599 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (2)

(57) [Claims] 1. A center plate for separating anode gas and cathode gas, and an opening for an electrode at the center having substantially the same outer dimensions as the center plate, and provided in parallel at a predetermined interval with the center plate interposed therebetween. Two mask plates that are in close contact with the center plate at the ends, and a punch plate that is in contact with the inner surface of the mask plate and that is provided so as to cover the opening for the electrode in parallel with the inner surface of the mask plate; Wherein the center plate is corrugated over the periphery of an outer peripheral end having an interval of. 2. The fuel cell separator according to claim 1, wherein the upper and lower intervals of the waveform have dimensions that fit into the predetermined interval of the mask plate.