JP3257757B2 - Fuel cell separator - Google Patents

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 the chemical energy of fuel into electric energy, and more particularly to a parallel flow internal manifold type separator for a molten carbonate fuel cell. It is.

[0002]

2. Description of the Related Art In a molten carbonate fuel cell (FIG. 7A), a thin flat electrolyte plate (tile) 1 is provided with a fuel electrode (anode).
2 and a single cell 4 sandwiched between flat electrodes of an air electrode (cathode) 3 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. The stacked batteries are called a stack.

As shown in FIG. 7B, a fuel gas (anode gas) 6 and an oxidizing gas (cathode gas) 7 are supplied to both surfaces of each cell in the stack. Flow (b) and countercurrent (c)), but parallel flow in terms of cooling by the fuel cell process gas (anode gas, cathode gas) and thermal stress generated in the separator;
In particular, cocurrent (b) is considered to be advantageous.

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

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

[0006]

As described above, the fuel cell separator comprises a partition plate for separating the anode gas and the cathode gas, a current collector for connecting each cell, and a gas for supplying the anode gas and the cathode gas to each cell. It has multiple functions such as manifold, etc.
Heat resistance to withstand high temperatures of about 700 ° C or higher, corrosion resistance to withstand highly corrosive molten carbonates, flatness and flexibility to form a wet seal between separators with electrolyte plates (tiles) containing molten carbonate, batteries Low electrical resistance, etc., which lowers the internal resistance of the device. To meet these demands, fuel cell separators have conventionally been manufactured by precision machining.However, in order to reduce power generation costs, it is necessary to form each component of the fuel cell separator by pressing. Have been.

However, since the flow path (reaction portion) of the separator formed by press working usually has a continuous waveform as shown in FIG. 7, if a laminated battery (stack) is formed using this separator, the cell 4 is There was a problem that it could not be supported at the same place from above and below. That is, in the corrugated portion formed by the press working, since the positions of the peaks and the valleys coincide with each other, the cell 4 is horizontally supported at the apex of the peak, and is pressed and sandwiched at the valley at the intermediate position. For this reason, a bending force acts on the cells 4 (anode, cathode, and tile) that are extremely brittle in a use state, and there is a possibility that cracks may occur in these cells.

In order to solve this problem, for example, a method of preparing two types of separators having different waveforms and turning over the separator for each cell may be considered. It is necessary to manufacture two sets of molds, not only is it very expensive to manufacture the molds, but it is virtually impossible to match the molding shapes of the two sets of molds (molding accuracy is ± About 0.1 mm is required). 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, and there is a problem that the separator cannot be used upside down.

The present invention has been made to solve such a problem. That is, an object of the present invention is to provide a fuel cell separator that can support the entire surface of a cell that performs a cell reaction from above and below at the same place, and that can be mass-produced by press working and that can significantly reduce cost. .

[0010]

According to the present invention, a cathode mask (11), a cathode collector (12), a center plate (13), an anode collector (14), and an anode mask (15) each having a substantially rectangular flat plate shape are provided. ) Is a component, and these are sequentially laminated fuel cell separators (10).
A plurality of cathode gas through holes (1
6) and an anode gas through-hole (17), each of which has a separator (10) inlet.
Side and the outlet side are alternately reversed so that each gas through hole (16, 1
7) are provided at the same position on the gas inlet side and the gas outlet side so that the cathode mask (1 ) can be stacked at the same position.
1) and the anode mask (15) have openings (11a, 15a) for accommodating electrodes in the center, respectively. The cathode collector (12) and the anode collector (14) have at least the openings (11a, 15a). The center plate (13) has a large number of through holes at corresponding positions, and the center plate (13) has a plurality of electrode irregularities (13) supporting the anode and the cathode.
a), and a plurality of mask irregularities (13b) supporting the cathode mask (11) and the anode mask (15), and each electrode irregularity (13a) is moved from the entrance side to the exit side.
A plurality of waveforms A, B, C, D extending in the transverse direction orthogonal to the flowing gas flow are press-formed, and the plurality of waveforms A, B, C, D are alternately formed from the gas inlet side to the gas outlet side. The peaks and valleys are positioned in an inverted manner, and the outer peripheral portions of the center plate (13), the anode mask (15) and the cathode mask (11) and the anode gas of the center plate (13) and the cathode mask (11). Inner end of through hole (17) and center plate (13)
And an inner end of the cathode gas through-hole (16) of the anode mask (14) is hermetically connected to each other, thereby providing a fuel cell separator.

According to the structure of the present invention, five plates each of a cathode mask (11), a cathode collector (12), a center plate (13), an anode collector (14) and an anode mask (15) each having a substantially rectangular flat plate shape are provided. The separator (10) can be completed simply by connecting the components described above by welding or the like, and the cost and time required for assembly can be significantly reduced.

The center plate (13) having the electrode irregularities (13a) and the mask irregularities (13b)
It can be easily formed by pressing a highly flexible thin plate, so that flexibility can be maintained, planar accuracy can be increased, and productivity is high, mass production is possible and significant cost reduction is possible. it can.

Further, each gas through hole (16, 17) is
Invert the separator (10) alternately on the inlet side and the outlet side
Each gas through hole (16, 17) can be laminated at the same position
Thus, the gas inlet and outlet sides are provided at the same position, and each electrode uneven portion (13a) is provided from the inlet side to the outlet side.
A plurality of waveforms A, B, C, D extending in the transverse direction orthogonal to the flowing gas flow are press-formed, and the plurality of waveforms A, B, C, D are alternately formed from the gas inlet side to the gas outlet side. Since the valleys are positioned upside down, the separator (1
0) are alternately reversed on the inlet side and the outlet side to form a stack, thereby forming the internal manifold (8a, 8).
The stack can be formed as it is without shifting the position of b), and the whole surface of the cell where the battery reaction is performed can be supported at the same place from above and below.

[0014]

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 denotes a parallel flow internal manifold type separator having a concave portion in which the cathode 3 (and the anode 2) is fitted in both center portions of both surfaces of the separator. Is provided. In the separator 10 of the present invention, the gas inlet side and the gas outlet side are formed symmetrically except for a flow path which will be described later, so that the separator 10 can be stacked with the inlet side and the outlet side alternately reversed. Further, the anode manifold 8a and the cathode manifold 8b are provided at the same position on the inlet side and the outlet side. Therefore, in this figure, for the following description, the upper manifold is set to the inlet side,
The lower manifold is referred to as an outlet side. However, the lower manifold may be turned upside down, and the lower manifold may be an inlet side and the upper manifold may be an outlet side. In addition, as for the gas flow, both gases may flow in the same direction or may flow in opposition.

As shown in FIG. 2, the separator 1 of the present invention
0 is a cathode mask 11 having a substantially rectangular flat plate shape,
The cathode collector 12, the center plate 13, the anode collector 14, and the anode mask 15 are used as constituent components, and are sequentially laminated. Further, each of the constituent parts 11, 12, 13, 14, and 15 is
A plurality of cathode gas through holes 16 and 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 in the upper and lower two sides, each of which is four, and the anode gas through-holes 17 are similarly provided in the two smaller sides. It is a round hole. Note that 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 located at the same position on the inlet side and the outlet side so that the separator 10 can be alternately stacked on the inlet side and the outlet side. Is provided.

In FIG. 2, the cathode mask 11 and the anode mask 15 have openings 11a and 15a for accommodating electrodes in the center, respectively, and the cathode 3 and the anode 2 are fitted into these portions, respectively. . Further, the cathode collector 12 and the anode collector 14
A plurality of through holes are provided at least at positions corresponding to the openings 11a and 15a, 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 located at the openings 11a and 15a and The power is supplied to the anode 2.

As shown in FIG.
Are the even (four in this figure) electrode irregularities 13a that support the anode and cathode formed by pressing.
And two mask concavities and convexities 13b supporting the cathode mask 11 and the anode mask 15. The electrode concavo-convex portion 13a is press-formed into a plurality of waveforms extending in a direction (lateral direction) orthogonal to the flow (top to bottom) of the gas flowing from the inlet side to the outlet side, thereby supporting the electrode and supporting its surface. A flow path along which gas flows is formed. In addition, the mask concave / convex portions 13b are provided with the gas through holes 16 and 17 respectively.
Irregularities radially provided around the periphery of the opening 11a, 1
5a comprises an uneven portion provided at the gas outflow portion. With this configuration, each process gas flows from the upper gas through holes 16 and 17 to the lower gas through holes 16 and 17, and the process gas flows through the through holes of the cathode collector 12 and the anode collector 14 to the openings 11 a and 15 a. It can be supplied to the located cathode 3 and anode 2.

Further, when the separators 10 are alternately inverted and stacked on the inlet side and the outlet side, the corrugated portions 13a of the respective electrodes are positioned so that the cells are supported at the same position from above and below. I have. That is, in this figure, assuming that the electrode uneven portions 13a are A, B, C, and D from above, the waveforms of A, B, C, and D are alternately inverted from the gas inlet side to the gas outlet side. Is positioned.

FIGS. 4A and 4B are a sectional view taken along the line A and a sectional view B in FIG. 1, respectively. The sectional view A corresponds to the portion A in FIG. 3, and the sectional view B corresponds to the portion D in FIG. Is equivalent to Also, FIG.
FIG. 4 is a cross-sectional view illustrating a usage state of the separator according to the present invention, and illustrates a portion A and a portion D in FIG. 3 when a stack (laminated battery) is formed by stacking separators 10 with the inlet side and the outlet side alternately inverted and stacked. Shows the cell 4 (A part above, D part below).

As is apparent from FIGS. 4 and 5, A, A of the electrode uneven portion 13a supporting the cathode 3 and the anode 2 are shown.
As described above, since the peaks and valleys of the waveform of the portion D are inverted, the peaks and valleys are inverted, and the peaks and valleys are set at A, and the upper and lower surfaces of the separator are left as shown in FIG. If the inlet side and the outlet side are alternately reversed, the upper part is the part A and the lower part is the D part. As shown by arrows in FIG. 5, the cell is sandwiched between the valley of the A part and the peak of the D part. That means
Further, since the peaks and valleys of the portion A and the portion D are inverted, each portion of the cell can be supported at the same position from above and below. Similarly, at the positions of B and C, the ridge of B and the valley of C coincide with each other, and each part of the cell can be supported at the same place from above and below. Can be supported at a point.

FIGS. 6A and 6B are cross-sectional views of FIGS.
It is sectional drawing. As shown in this figure, the center plate 13, the anode mask 15, the outer peripheral portion of the separator of the cathode mask 11 (part A in FIG. 5), and the center plate 13 and the anode gas through-hole 1 of the cathode mask 11.
The inner end portion (portion B in FIG. 5) and the inner end portion (portion C in FIG. 5) of the center plate 13 and the cathode gas through hole 16 of the anode mask 14 are air-tightly connected to each other. These connections can be made by any means, such as welding,
It is preferable to use brazing, bonding, caulking, or the like.

With this configuration, the cathode manifold 8
b from the center plate 1
The anode gas supplied from the anode manifold 8 a can be supplied between the upper surface of the center plate 13 and the anode mask 15. 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 irregularities 13a (see FIG. 3) of the center plate 13, and the cathode collector 12 and the anode The cathode 3 located at the openings 11a and 15a through the through hole of the collector 14
And the anode 2 where it reacts to generate electricity. 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 by simply connecting the five components of the cathode mask 11, the cathode collector 12, the center plate 13, the anode collector 14, and the anode mask 15 each having a substantially rectangular flat plate shape by welding or the like, The cost and time required for assembly can be greatly reduced.

The electrode irregularities 13a and the mask irregularities 1
3b can be easily formed by pressing a highly flexible thin plate, so that flexibility can be maintained, planar accuracy can be increased, and productivity is high and large quantities can be produced. Production is possible and significant cost reduction is possible.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously changed without departing from the gist of the present invention.

[0028]

As described above, the fuel cell separator of the present invention can support the entire surface of a cell for performing a cell reaction at the same location from above and below, and can be mass-produced by press working, thereby significantly reducing cost. Has excellent effects such as

[Brief description of the 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 constituting a separator.

4 is a sectional view taken along the line A and B in FIG.

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

6 is a sectional view taken along the line C and D in FIG. 1;

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

FIG. 8 is a schematic view of a separator formed by conventional press working.

[Explanation of symbols]

 Reference Signs List 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 unevenness 13b Mask unevenness 14 Anode collector 15 Anode mask 15a Opening 16 Cathode gas through hole 17 Anode gas through hole

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-3-57162 (JP, A) JP-A-2-168563 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01M 8/00-8/24

Claims (1)

(57) [Claims] 1. A cathode mask (11), a cathode collector (12), a center plate (13), an anode collector (14), and an anode mask (15) each having a substantially rectangular flat plate shape, and these are sequentially laminated. A fuel cell separator (10), wherein each of the components has a plurality of cathode gas through holes (16) and anode gas through holes (17) along two opposing sides, respectively. Each gas through hole (16, 17)
Turns the separator (10) between the inlet and outlet alternately
And the gas through holes (16, 17) are stacked at the same position.
The cathode mask (11) and the anode mask (15) are provided at the same position on the gas inlet side and the gas outlet side.
Openings (11a, 15
a), wherein the cathode collector (12) and the anode collector (14) have at least the openings (11a, 15).
The center plate (13) has a plurality of electrode irregularities (13a) supporting an anode and a cathode, and a cathode mask (11) and an anode mask (15). And a plurality of mask uneven portions (13b) to be supported.
3a) is press-formed into a plurality of waveforms A, B, C, D extending in the transverse direction orthogonal to the flow of gas flowing from the inlet side to the outlet side , and the plurality of waveforms A, B, C, D are: The peaks and valleys are alternately inverted and positioned from the gas inlet side to the gas outlet side, and the center plate (13) and the anode mask (1) are positioned.
5), the outer periphery of the separator of the cathode mask (11), the center plate (13) and the cathode mask (1).
The inner end of the anode gas through hole (1) of 1) and the inner end of the cathode gas through hole (16) of the center plate (13) and the anode mask (14) are airtightly connected to each other. A fuel cell separator.