JP2000235861A - Stack structure for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing costs further by decreasing kinds of required press-molding and lessening portions to be bonded. SOLUTION: In a stack structure for a fuel cell, wherein a cell 4 is sandwiched between separators 5 so as to be laminated the separators, comprise a center plate 10 composed of press-molded single thin plate and collectors 9a, 9c fitted into an anode side and a cathode side of the center plate 10. The center plate 10 has flushed outer flat portions 11a, 11c provided entire periphery while swelling toward an anode and cathode side, respectively, so as to be brought into direct contact with an electrolytic plate 1 and then to form a wet seal. The center plate 10 also has crest portions 12a, 12c swelling toward the anode and cathode side, respectively, so as to support the collectors 9a, 9c. Manifold holes 13a, 13c are arranged at the crest portions located at the both ends of the anode and cathode and the cell 4 to be brought into contact therewith is provided with manifold holes 13a and 13c so as to therethrough supply an anode gas and cathode gas to each cells.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stack structure of a molten carbonate fuel cell.

[0002]

2. Description of the Related Art In a molten carbonate fuel cell (FIG. 4A), a thin plate-like 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 4, the separator 5 is used to form a battery in which the separators are stacked in multiple stages. The stacked batteries are called a stack.
Further, as means for supplying the process gas to each cell in the stack 6, as shown in FIG. 4B, an external manifold system (a) for directly supplying the process gas from the side of the stack, and a through manifold 8 perpendicular to the separator itself.
And an internal manifold system (b) for supplying a process gas to each cell via this manifold.

The above-described fuel cell separator has a plurality of functions such as a partition plate for separating anode gas and cathode gas, a current collector for connecting each cell, and a gas manifold for supplying anode gas and cathode gas to each cell. Heat resistance to withstand high temperatures of about 700 ° C. or higher, corrosion resistance to withstand molten carbonates, flatness and flexibility to form a wet seal between separators with an electrolyte plate (tile) containing molten carbonate, Low electrical resistance, which lowers the internal resistance of the battery, is required. In order to satisfy these demands and reduce costs, instead of conventional precision machining, a corrugated separator in which the flow path is formed by a corrugated plate, and a press-type separator in which each part is formed by pressing, Already developed.

[0004]

The corrugated separator has the advantage that the corrugated plate is adhered to both surfaces of the central flat plate to form the flow path, so that it is excellent in flatness accuracy and flexibility and can be easily enlarged. However, on the other hand, there is a problem that the cost of processing the corrugated plate and the cost of assembling the separator are high, and mass production cannot be performed at low cost. On the other hand, in the press-type separator, since both flow paths are integrally formed by press working, there is a high possibility that the processing cost and the assembly cost can be significantly reduced. For this reason, press-type separators that can be mass-produced by press working have been proposed, and some of them have already been implemented (for example, Japanese Patent Application Laid-Open No. 9-63 by the present applicant).
599).

FIG. 5 is a cathode side plan view of a press-type separator disclosed in Japanese Patent Application Laid-Open No. 9-63599, and FIG.
3 is a partial cross-sectional view taken along line AA of FIG. In these figures, 8a and 8b are an anode manifold and a cathode manifold, respectively, and A and C in the figures are an anode gas flow path and a cathode gas flow path, respectively. That is,
This press-type separator includes three press-formed products (center plate 5b, cathode mask plate 5c, anode mask plate 5a) and two perforated plates (cathode collector 9c, anode collector 9a). The structure was such that the periphery of the molded product and the manifold were joined and integrated. As a result, cell 4
The structure is sandwiched between the cathode collector 9c and the anode collector 9a.

However, even with the above-mentioned press-type separator, three press-formed products are necessary, and there are many joining portions for joining thin plates. There is a problem that tools and pre- and post-processing are required, and as a result, the manufacturing cost is still high.

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 stack structure capable of further reducing the number of types of required press-formed products and the number of joints, thereby further reducing manufacturing costs.

[0008]

According to the present invention, there is provided a fuel cell stack structure in which a cell (4) is sandwiched between separators (5), wherein the separator is a press-formed single unit. Center plate made of thin plate (10)
And an anode collector (9a) and a cathode collector (9c) fitted respectively on the anode side and the cathode side of the center plate. The cell comprises an electrolyte plate (1), an anode (2) sandwiching the electrolyte plate (1), and an anode (2). The center plate is swelled on the anode side and is provided with a flush anode outer peripheral flat portion (11a) provided on the entire periphery of the outer edge portion, and the center plate is swelled on the cathode side and is formed on the entire inner periphery of the anode outer peripheral flat portion. And a flat outer surface of the cathode (11c) provided on the anode plate, each of which is in direct contact with the electrolyte plate to form a wet seal therebetween, and the center plate further swells to the anode side to form the anode collector (9).
a) and an anode ridge (12c) supporting the cathode collector (9c) bulging to the cathode side. The anode ridge located at both ends of the anode and the cell in contact therewith are provided. Is a fuel cell stack structure, characterized in that an anode manifold hole (13a) is provided, and a cathode peak located at both ends of the cathode and a cell in contact with the cathode peak are provided with a cathode manifold hole (13c). Is provided.

According to the structure of the present invention, the separator is substantially one press-formed product (center plate).
Since the anode collector and cathode collector are only fitted on both sides, there is no thin plate joining process.
Flatness accuracy and flexibility can be easily secured, and almost no jigs or pre-processing and post-processing are required, so that manufacturing costs can be greatly reduced. Further, the anode outer peripheral flat portion (11a) and the cathode outer peripheral flat portion (11c) are respectively provided on the electrolyte plate (1).
Therefore, a wet seal is formed therebetween, and an anode space and a cathode space which are hermetically held by the wet seal can be formed on both surfaces of the center plate (10). Furthermore, the anode peak (12
Since a) and the cathode peak (12c) support the anode collector (9a) and the cathode collector (9c), respectively, the surface pressure acting on the cell can be supported and a flow path can be formed therebetween. An anode manifold hole (13a) is provided in an anode crest located at both ends of the anode and a cell in contact therewith, and a cathode manifold hole (13a) is provided in a cathode crest located at both ends of the cathode and a cell in contact therewith. Since 13c) is provided, the anode gas and the cathode gas can be supplied to both surfaces of each center plate through the respective manifold holes to cause a battery reaction.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS 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 partial plan view on the cathode side of a stack structure according to the present invention, in which an anode collector, a cathode collector, and cells, which will be described later, are omitted, and only a center plate 10 is substantially shown. Also, FIG.
FIG. 3 is a cross-sectional view taken along the line BB of FIG. 1 and FIG. 3 is an exploded explanatory view of FIG. 2. In these figures, the anode collector, the cathode collector, and the cell are shown. In each of the drawings, common portions are denoted by the same reference numerals, and redundant description will be omitted.

As shown in FIG. 3, in the fuel cell stack structure of the present invention, a stack is formed by sandwiching and stacking cells 4 between separators 5. Cell 4
Electrolyte plate 1 and anode 2 and cathode 3 sandwiching the same
Consists of

The separator 5 includes a center plate 10 made of a single thin plate formed by press molding, and an anode collector 9a fitted on the anode side (lower side in the figure) and the cathode side (upper side in the figure) of the center plate 10, respectively. And a cathode collector 9c.

As shown in FIGS. 1 to 3, the center plate 10 swells on the anode side and is flush with the outer periphery flat portion 11a provided on the entire periphery of the outer edge portion. And a flat surface 11c on the outer periphery of the cathode provided on the entire periphery, and each is in direct contact with the electrolyte plate 1 to form a wet seal therebetween. With this configuration, it is possible to form the anode space A and the cathode space C airtightly held by wet sealing on both surfaces of the center plate 10.

The center plate 10 further includes an anode ridge 12a supporting the anode collector 9a swelling on the anode side and a cathode ridge 12c supporting the cathode collector 9c swelling on the cathode side. Mountain part 12a,
12c is preferably formed flat and the collector 9
When the anode 2 and the cathode 3 having the same shape as those a and 9c are fitted on the surface, the height is set to be flush with the outer peripheral flat portions 11a and 11c. With this configuration, the surface pressure acting on the cell 4 can be supported by the peaks 12a and 12c, and a flow path for the anode gas and the cathode gas can be formed between the cell 4 and the surface pressure.

Further, as shown in FIG. 1, the anode peaks 12a located at both ends of the anode and the cells 4
Is provided with an anode manifold hole 13a, and a cathode peak portion 12c located at both ends of the cathode and a cell 4 in contact with the cathode peak portion 12c are provided with a cathode manifold hole 13c. With this configuration, each manifold hole 13
The anode gas and the cathode gas are supplied from a lower (or upper) holder or the like (not shown) through a and 13c, and the anode gas and the cathode gas can be supplied to both surfaces of each center plate to cause a battery reaction.

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

[0017]

According to the above-described structure, the separator can be formed by press-forming substantially one thin plate.
The material cost (yield of 40% or less) and processing cost of the conventional mask plate can be significantly reduced. In addition, since the periphery of the cell is more flexible than in the conventional structure, it is possible to prevent performance degradation due to thermal deformation. Therefore, the fuel cell stack structure of the present invention has excellent effects such as greatly reducing the number of types of required press-formed products and reducing the number of joints, thereby greatly reducing manufacturing costs. .

[Brief description of the drawings]

FIG. 1 is a partial plan view on the cathode side of a stack structure according to the present invention.

FIG. 2 is a sectional view taken along line BB of FIG.

FIG. 3 is an exploded explanatory view of FIG. 2;

FIG. 4 is an explanatory view of a conventional molten carbonate fuel cell.

FIG. 5 is a diagram illustrating a stack structure of a conventional fuel cell.

6 is a sectional view taken along line AA of FIG.

[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) 5a anode mask plate 5b center plate 5c cathode mask plate 6 stack 8 internal manifold 8a anode manifold 8b cathode manifold 9a Anode collector 9c Cathode collector 10 Center plate 11a Anode outer peripheral flat portion 11c Cathode outer peripheral flat portion 12a Anode peak portion 12c Cathode peak portion 13a Anode manifold hole 13c Cathode manifold hole

Claims (1)

[Claims] 1. A fuel cell stack structure in which cells (4) are sandwiched between separators (5) and stacked, wherein the separator comprises a center plate (10) made of a single press-formed thin plate. An anode collector (9a) and a cathode collector (9c) fitted respectively on the anode side and the cathode side of the center plate,
The cell comprises an electrolyte plate (1), an anode (2) and a cathode (3) sandwiching the electrolyte plate, and the center plate swells toward the anode side and is flush with the outer peripheral flat portion provided on the entire outer periphery. (11a)
And a flattened outer peripheral flat portion (11c) provided on the entire circumference inside the flat outer peripheral portion of the anode on the cathode side, each of which is in direct contact with the electrolyte plate to form a wet seal therebetween. The plate further comprises an anode ridge (12a) supporting the swelling anode collector (9a) on the anode side and a cathode ridge (12c) supporting the swelling cathode collector (9c) on the cathode side. An anode manifold hole (13a) is provided in the anode ridge and the cell that contacts the anode ridge, and a cathode manifold hole (13c) is provided in the cathode ridge located at both ends of the cathode and the cell that contacts the anode ridge. And a fuel cell stack structure.