JPH0963599A - Separator for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separator for a fuel cell capable of supporting the whole surface of a cell for performing cell reaction in the same portion, producing in large quantities by press working, and remarkably reducing the cost. SOLUTION: A separator for a fuel cell has a flow path which supports an electrode and lets gas flow along the surface of the electrode, formed with a press, and the inlet side and the outlet side of gas except for the flow path are symmetrically formed. The flow path is arranged from the inlet side to the outlet side in order, and consists of even numbered electrode recessed and projecting parts A, B, C, and D formed in wave form in the direction perpendicularly crossing to the flow of gas. Each electrode recessed and projecting part 13a, when the separators are stacked by alternately turning round the inlet side and the outlet side, positions the cell with the top of the wave form so as to support the cell between the separators in the same portion from upper and lower parts.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell separator for directly converting chemical energy of a fuel into electric energy, and more particularly to a parallel flow internal manifold type separator for a molten carbonate fuel cell. Is.

[0002]

2. Description of the Related Art In a molten carbonate fuel cell (FIG. 7A), a thin flat electrolyte plate (tile) 1 is used as a fuel electrode (anode).
2 and an air electrode (cathode) 3 sandwiched between flat electrodes 4, and a conductive bipolar plate (separator) 5
Consists of Since the voltage of the separator 5 is low (about 0.8 V) in the single cell 1, the separator 5 is used to form a battery in which these are stacked in multiple stages. Stacked batteries are called a stack.

As shown in FIG. 7B, the fuel gas (anode gas) 6 and the oxidizing gas (cathode gas) 7 are supplied to both sides of each cell in the stack as shown in FIG. 7B. There is a flow (b) and a counterflow (c), but there is a parallel flow in terms of cooling by the process gas (anode gas, cathode gas) of the fuel cell and thermal stress generated in the separator,
Particularly cocurrent (b) is considered to be advantageous.

Further, as a means for supplying the process gas to each cell in the stack, as shown in FIG. 7C, an external manifold system (a) for directly supplying the process gas from the side surface of the stack and a through hole perpendicular to the separator itself are used. There is an internal manifold system (b) which is provided with a manifold 8 and supplies process gas to each cell via this manifold. However, the internal manifold system is not affected by a change in stack height or unevenness of the stack side surface. Are considered excellent.

The present invention relates to such a parallel flow internal manifold type separator.

[0006]

As described above, the fuel cell separator is composed of a partition plate for partitioning the anode gas and the cathode gas, a current collector for connecting the cells, and a gas for supplying the anode gas and the cathode gas to the cells, respectively. It has multiple functions such as a manifold, heat resistance to withstand high temperatures of about 700 ° C or higher, corrosion resistance to highly corrosive molten carbonate, and electrolyte plates (tiles) containing molten carbonate between separators. In addition, the flatness and flexibility of forming a wet seal, and low electric resistance that lowers the internal resistance of the battery are required. In order to meet these requirements, fuel cell separators have conventionally been manufactured by precision machining, but in order to reduce power generation costs,
It is desired to mold each component of the fuel cell separator by press working.

However, since the flow path (reaction part) of the separator formed by pressing usually has a continuous waveform as shown in FIG. 8, when a laminated battery (stack) is constructed using this separator, the cell 4 is There was a problem that it could not be supported in the same place from above and below. That is, in the corrugated portion formed by the press working, the positions of the peaks and the troughs are the same in each separator, so that the cells 4 are supported horizontally at the apex of the peaks and are pressed and sandwiched at the troughs at their intermediate positions. Therefore, the bending force may act on the cells 4 (anode, cathode, tile) that are extremely brittle in use, and cracks may occur in them.

In order to solve this problem, it is conceivable that, for example, two kinds of separators having different waveforms are prepared, and the separators are turned over every one cell. Since it is necessary to manufacture two sets of molds, it is very expensive to manufacture the molds, and it is practically impossible to match the molding shapes of the two sets of molds (the molding accuracy is ± About 0.1 mm is required). In addition, in order to improve the corrosion resistance of the fuel cell, it is necessary to use different materials on the anode side and the cathode side, which means that the separator cannot be turned over and used.

The present invention was created to solve such a problem. That is, an object of the present invention is to provide a fuel cell separator capable of supporting the whole cell surface for cell reaction at the same position from above and below, capable of mass production by press working, and capable of significant cost reduction. .

[0010]

According to the present invention, in a fuel cell separator in which a flow path for supporting an electrode and a flow of gas along the surface is press-molded, the gas inlet side is excluded except for the flow path. And the outlet side are formed symmetrically, and the flow path is composed of an even number of electrode irregularities that are sequentially arranged from the gas inlet side to the gas outlet side and are corrugated in the direction orthogonal to the gas flow. The concavo-convex portion is positioned in a corrugated shape so that when the separators are laminated by alternately inverting the inlet side and the outlet side, the corrugations are positioned so as to support the cells at the same position from above and below between them. A separator is provided.

According to the structure of the present invention, the gas inlet side and the gas outlet side are formed symmetrically except for the flow path, so that the inlet side and the outlet side are alternately inverted and laminated to form a stack. be able to. Further, in this case, since the corrugations of each electrode uneven portion are positioned so as to support the cell at the same position from above and below between them, by alternately inverting the inlet side and the outlet side to form a stack, In addition, it is possible to support the entire surface of the cell that performs the battery reaction at the same location from above and below.

According to a preferred embodiment of the present invention, a plurality of internal manifolds are provided on the inlet side and the outlet side,
In addition, the internal manifold is provided at the same position on the inlet side and the outlet side so that the separators can be laminated by alternately inverting the inlet side and the outlet side. With this configuration, even when the separators are alternately inverted and laminated on the inlet side and the outlet side, the stack can be configured as it is without the position of the internal manifold being displaced.

Further, according to the present invention, there is provided a fuel cell separator in which a cathode mask, a cathode collector, a center plate, an anode collector, and an anode mask, each of which has a substantially rectangular flat plate shape, are components and are sequentially stacked. , Each of the components has a plurality of through holes for cathode gas and through holes for anode gas along two opposing sides, and the through holes for gas are at the same position on the gas inlet side and the gas outlet side. The cathode mask and the anode mask each have an opening for accommodating an electrode in the central portion, and the cathode collector and the anode collector have a large number of through holes at least at positions corresponding to the openings, and The plate includes a plurality of electrode irregularities that support the anode and the cathode, and a plurality of electrodes that support the cathode mask and the anode mask. Each electrode uneven portion is press-formed into a waveform in a direction orthogonal to the gas flow, and this waveform is positioned by inverting the peaks and valleys alternately from the gas inlet side to the gas outlet side. The center plate, the anode mask, and the cathode mask have separator outer peripheral portions, the center plate and the cathode mask have anode gas through holes, and the center plate and the anode mask have cathode gas through holes. There is provided a fuel cell separator, characterized in that its ends are hermetically connected to each other.

According to the structure of the present invention, the cathode mask, the cathode collector, the center plate, the anode collector, and the anode mask each having a substantially rectangular flat plate shape are provided.
The separator can be completed only by connecting the components of the sheet by welding or the like, and the cost and time required for assembly can be significantly reduced. Further, the center plate having the electrode uneven portion and the mask uneven portion can be easily formed by pressing a highly flexible thin plate, so that the flexibility can be maintained and the plane accuracy can be improved. In addition, it is highly productive and can be mass-produced, resulting in a significant cost reduction.

Further, each gas through hole is provided at the same position on the gas inlet side and the gas outlet side, and each electrode uneven portion is
It is press-formed into a corrugated shape in the direction orthogonal to the gas flow, and this corrugated material is positioned so that the peaks and valleys are alternately inverted from the gas inlet side to the gas outlet side. By inverting and stacking to form a stack, it is possible to form the stack as it is without shifting the position of the internal manifold, and in the meantime, it is possible to support the entire cell where the battery reaction occurs from the top and bottom at the same location. it can.

[0016]

Preferred embodiments of the present invention will be described below with reference to the drawings. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted. FIG. 1 is a cathode side plan view of a separator according to the present invention, FIG. 2 is an exploded view of the separator of FIG. 1, and FIG. 3 is a cathode side plan view of a center plate constituting the separator. In these figures, the upper side is the cathode side and the lower side is the anode side, but the present invention is not limited to this, and the upper side may be the anode side and the lower side may be the cathode side.

Referring to FIG. 1, a separator 1 according to the present invention.
Reference numeral 0 is a parallel-flow internal manifold type separator, which has a recessed portion into which the cathode 3 (and the anode 2) is fitted in the central portion of both surfaces of the separator, and the anode manifold 8a and the cathode manifold 8b which penetrate the separator in the upper and lower portions in the figure. Is provided. In the separator 10 of the present invention, the inlet side and the outlet side of the gas are formed symmetrically, except for the flow paths described later, so that the inlet side and the outlet side of the separator 10 can be alternately inverted and laminated. Further, the anode manifold 8a and the cathode manifold 8b are also provided at the same position on the inlet side and the outlet side. Therefore, in this figure, for the following explanation, the upper manifold is
The lower manifold is called the outlet side, but it is also possible to turn the figure upside down so that the lower manifold is the inlet side and the upper manifold is the outlet side. As for the gas flow, both gases may flow in the same direction or may flow in opposite directions.

As shown in FIG. 2, the separator 1 of the present invention.
0 is a substantially rectangular flat plate-shaped cathode mask 11,
The cathode collector 12, the center plate 13, the anode collector 14, and the anode mask 15 are used as components, and these are sequentially stacked. In addition, each of the component parts 11, 12, 13, 14, and 15 faces each other.
A plurality of cathode gas through holes 16 and a plurality of anode gas through holes 17 are provided along the sides (upper and lower sides in the figure).
In this figure, the cathode gas through holes 16 are larger round holes provided with four holes each on the upper and lower sides, and the anode gas through holes 17 are similarly provided with two small holes each. It is a round hole. The arrangement of the gas through holes 16 and 17 is not limited to this figure, and can be set freely.

Further, the plurality of cathode gas through holes 16 and the plurality of anode gas through holes 17 are arranged at the same position on the inlet side and the outlet side so that the separator 10 can be laminated by alternately inverting the inlet side and the outlet side. It is provided. Further, in FIG. 2, the cathode mask 11 and the anode mask 15 have openings 11a and 15a for accommodating electrodes respectively in the central portions, and the cathode 3 and the anode 2 are fitted into these portions, respectively. In addition, the cathode collector 12
And the anode collector 14 has at least the openings 11a, 1
5a has a large number of through holes at positions corresponding to 5a, and the process gas supplied to both surfaces of the center plate 13 from the manifolds 8a and 8b (see FIG. 1) is supplied to the cathode 3 and the anode 2 located in the openings 11a and 15a. It is supposed to do.

As shown in FIG. 3, the center plate 13
Is an even number (four in this figure) of electrode irregularities 13a supporting the anode and cathode formed by press working.
And two mask irregularities 13b supporting the cathode mask 11 and the anode mask 15. The electrode concavo-convex portion 13a is press-formed into a corrugated shape in a direction (lateral direction) orthogonal to the gas flow (from top to bottom).
A flow path is formed which supports the electrode and along which the gas flows. Further, the mask uneven portion 13b includes an uneven portion radially provided around each of the gas through holes 16 and 17, and
The openings 11a and 15a are formed of uneven portions provided at the gas outflow portions. With this configuration, the upper gas through holes 16 and 1
7 through the gas through holes 16 and 17 on the lower side, so that the cathode collector 12 and the anode collector 14
The process gas can be supplied to the cathode 3 and the anode 2 located in the openings 11a and 15a through the through holes.

Furthermore, when the separator 10 is laminated by alternately inverting the inlet side and the outlet side, the corrugated portions 13a are positioned so that the cells are supported at the same position from above and below between them. There is. That is, in this figure, assuming that the electrode concavo-convex portions 13a are A, B, C, and D from the top, the waveforms of A, B, C, and D are alternately inverted from the gas inlet side to the gas outlet side. Have been positioned.

FIGS. 4A and 4B are a sectional view taken along the line A and a sectional view taken along the line B in FIG. 1, respectively. The sectional view A corresponds to the portion A in FIG. Equivalent to. In addition, FIG.
FIG. 4 is a cross-sectional view showing a use state of the separator according to the present invention, which is a portion A and a portion D of FIG. 3 when the separator 10 is alternately inverted and laminated to form a stack (a laminated battery). The cell 4 (the upper part is the A part and the lower part is the D part) sandwiched between the two.

As is clear from FIGS. 4 and 5, A of the electrode uneven portion 13a supporting the cathode 3 and the anode 2 is
As described above, in the waveform of the D portion, the peaks and troughs are inverted and positioned, so that A is the position of the trough and D is the peak, and the upper and lower surfaces of the separator are left unchanged as shown in FIG. When the inlet side and the outlet side are alternately inverted and stacked, when the upper part is the A part and the lower part is the D part, the cell is sandwiched by the valley of the A part and the peak of the D part as shown by the arrow in FIG. And then
Moreover, since the peaks and valleys of the A section and the D section are reversed, each part of the cell can be supported at the same position from above and below. Similarly, at the positions of B and C, the peaks of B and the valleys of C coincide with each other, so that each part of the cell can be supported at the same position from above and below. Can be supported in place.

FIGS. 6 (A) and 6 (B) are sectional views taken along the line C and D of FIG.
It is sectional drawing. As shown in this figure, the separator outer peripheral portions (A in FIG. 5) of the center plate 13, the anode mask 15, and the cathode mask 11, and the anode gas through holes 1 of the center plate 13 and the cathode mask 11.
An inner end portion (B portion in FIG. 5) of 7 and an inner end portion (C portion in FIG. 5) of the through hole 16 for the cathode gas of the center plate 13 and the anode mask 14 are airtightly connected to each other. These connections may be made by any means, such as welding,
It is good to use brazing, adhesion, or caulking.

With this configuration, the cathode manifold 8
The cathode gas supplied from b is supplied to the center plate 1
3 and the cathode mask 11, and the anode gas supplied from the anode manifold 8a can be supplied between the lower surface of the center plate 13 and the anode mask 15. Further, as shown in FIG. 1, the cathode gas and the anode gas respectively supplied to the upper and lower surfaces of the center plate 13 flow downward through the electrode uneven portion 13a (see FIG. 3) of the center plate 13, and the cathode collector 12 and the anode collector Cathode 3 located in openings 11a and 15a through the through hole of collector 14.
And reach the anode 2 where they react and generate electricity. Further, the unreacted gas and the reaction product flow further downward and are discharged to the outside from the lower manifolds 8a and 8b, respectively.

As described above, according to the configuration of the present invention,
The separator 10 can be completed only by connecting the five components of the substantially rectangular flat plate-shaped cathode mask 11, cathode collector 12, center plate 13, anode collector 14, and anode mask 15 by welding or the like. The cost and time required for assembly can be significantly reduced.

Further, the center plate 13 having the electrode uneven portion and the mask uneven portion can be easily formed by pressing a highly flexible thin plate.
The flexibility can be maintained, the plane accuracy can be improved, the productivity is high, the mass production is possible, and the cost can be greatly reduced. It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various changes can be made without departing from the spirit of the present invention.

[0028]

As described above, the fuel cell separator of the present invention can support the entire cell surface for cell reaction at the same position from the top and bottom, and can be mass-produced by press working, resulting in a significant cost reduction. It has excellent effects such as

[Brief description of drawings]

FIG. 1 is a cathode side plan view of a separator according to the present invention.

FIG. 2 is an exploded view of the separator of FIG.

FIG. 3 is a plan view on the cathode side of a center plate forming a separator.

FIG. 4 is a cross-sectional view taken along the line A and the line B of FIG.

FIG. 5 is a cross-sectional view showing a usage state of the separator according to the present invention.

6 is a cross-sectional view taken along the line C and the line D of FIG.

FIG. 7 is an explanatory diagram of a conventional molten carbonate fuel cell.

FIG. 8 is a schematic view of a conventional separator manufactured by pressing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrolyte plate (tile) 2 Fuel electrode (anode) 3 Air electrode (cathode) 4 Single cell 5 Bipolar plate (separator) 6 Fuel gas (anode gas) 7 Oxidizing gas (cathode gas) 8 Manifold 8a Anode manifold 8b Cathode manifold 9 Anode gas opening 10 Separator 11 Cathode mask 11a Opening 12 Cathode collector 13 Center plate 13a Electrode uneven portion 13b Mask uneven portion 14 Anode collector 15 Anode mask 15a Opening 16 Cathode gas through hole 17 Anode gas through hole

Claims (3)

[Claims] 1. A fuel cell separator in which a flow path through which an electrode is supported and a gas flows along a surface of the electrode is press-molded, and a gas inlet side and a gas outlet side are formed symmetrically except the flow path, The flow path is sequentially arranged from the gas inlet side to the gas outlet side,
It consists of an even number of electrode concavo-convex portions formed in a waveform in the direction orthogonal to the gas flow. The fuel cell separator is characterized in that the corrugations are positioned so as to support the same at the same position. 2. A plurality of internal manifolds are provided on the inlet side and the outlet side, and the internal manifolds are the same on the inlet side and the outlet side so that the separators can be laminated by alternately inverting the inlet side and the outlet side. The fuel cell separator according to claim 1, wherein the separator is provided at a position. 3. A fuel cell separator in which a cathode mask, a cathode collector, a center plate, an anode collector, and an anode mask each having a substantially rectangular plate shape are used as constituent parts, and these are sequentially stacked. A plurality of cathode gas through-holes and anode gas through-holes are provided along two opposing sides, and each gas through-hole is provided at the same position on the gas inlet side and the gas outlet side, The cathode mask and the anode mask each have an opening for accommodating an electrode in the central portion, the cathode collector and the anode collector have a large number of through holes at least at positions corresponding to the openings, and the center plate includes the anode and the cathode. A plurality of electrode irregularities supporting the cathode mask and the anode mask. Each of the electrode concavo-convex portions is press-molded into a waveform in a direction orthogonal to the flow of gas, and the waveform is positioned such that peaks and valleys are alternately inverted from the gas inlet side to the gas outlet side, The separator, the outer peripheral portion of the plate, the anode mask, and the cathode mask, the inner end portion of the through hole for the anode gas of the center plate and the cathode mask, and the inner end portion of the through hole for the cathode gas of the center plate and the anode mask are respectively Airtightly connected,
A fuel cell separator characterized by the above.