JP6891777B2 - Fuel cell single cell - Google Patents

Description

The present invention relates to a single cell of a fuel cell.

It is known that a fuel cell single cell constitutes a fuel cell stack by being laminated along a fastening member. In the fuel cell single cell described in Patent Document 1, a cushioning member made of an insulating resin or the like is provided in a recess where the fastening member at the end of each separator is fitted. When stacking the fuel cell single cells, the cushioning member comes into contact with the fastening member to regulate the positions of the fastening member and the fuel cell single cell, so that the misalignment during stacking can be reduced.

Japanese Unexamined Patent Publication No. 2013-211240

However, when a cushioning member is provided on each separator as a separate member, the work of attaching the cushioning member to the separator becomes complicated. Therefore, a fuel cell single cell capable of reducing the complexity of work has been desired.

The present invention has been made to solve the above-mentioned problems, and can be realized as the following forms.
According to one embodiment of the present invention, a fuel cell single cell for forming a fuel cell stack is provided. This fuel cell single cell is abbreviated so as to sandwich a power generator plate having a power generation body including a membrane electrode assembly and a frame-shaped resin sheet joined around the power generation body, and the power generation body plate. A pair of rectangular separators are provided, the pair of separators have first recesses provided on a pair of short sides or a pair of long sides, respectively, and the resin sheet comprises the pair of separators and the power generation. When viewed from the stacking direction of the body plate, it has a second recess extending toward the inner peripheral side of the first recess from the first recess at a position facing the first recess, and the second recess. A convex portion is provided on at least a part of a pair of surfaces which is the inner circumference of the concave portion and is connected to the open end of the second concave portion. The present invention can also be realized in the following forms.

According to one embodiment of the present invention, a fuel cell single cell for forming a fuel cell stack is provided. This fuel cell unit has a generator plate including a generator including a membrane electrode assembly and a frame-shaped resin sheet joined around the generator; a substantially rectangular shape so as to sandwich the generator plate. The pair of separators have a first recess provided on each of a pair of short sides or a pair of long sides; the resin sheet comprises the pair of separators and the power generator. When viewed from the stacking direction of the plates, it has a second recess extending toward the inner peripheral side of the first recess from the first recess at a position facing the first recess; the second recess. A convex portion is provided on at least a part of the inner circumference of the. According to the fuel cell single cell of this form, the convex portion provided in the second concave portion and the guide member inserted into the first concave portion when stacking the plurality of fuel cell single cells come into contact with each other to provide fuel for the guide member. Regulate the position of a single battery cell. Since this convex portion is provided in the second concave portion of the resin sheet, the work at the time of laminating can be simplified as compared with the conventional case. Therefore, the complexity of the work can be reduced.

The present invention can be realized in various forms, for example, as a fuel cell stack or a fuel cell in which a plurality of fuel cell single cells are stacked, or as a method for manufacturing a fuel cell single cell. It is possible to realize with.

It is explanatory drawing of the fuel cell single cell in one Embodiment of this invention. It is sectional drawing in the case of stacking a plurality of fuel cell single cells. It is an enlarged view of the part A of FIG. It is explanatory drawing of an example in which a fuel cell single cell is laminated. It is an enlarged view of the part A of FIG. 1 in another embodiment. It is an enlarged view of the part A of FIG. 1 in still another embodiment. It is an enlarged view of the part A of FIG. 1 in still another embodiment.

A. First Embodiment:
FIG. 1 is an explanatory diagram of a fuel cell single cell 100 according to an embodiment of the present invention. The fuel cell single cell 100 is a fuel cell single cell for forming a polymer electrolyte fuel cell stack that generates electricity by receiving the supply of hydrogen and oxygen as reaction gases. The fuel cell single cell 100 includes a pair of separators 40a and 40b that sandwich the power generator plate 25 having the power generator 10 and the resin sheet 20. FIG. 1 shows the x-axis, y-axis, and z-axis that are orthogonal to each other. These axes correspond to the axes shown in FIGS. 2 and later.

The power generator 10 includes an electrolyte membrane (not shown), a catalyst layer (not shown) formed adjacent to both sides of the electrolyte membrane, and a gas diffusion layer (not shown). The electrolyte membrane is a solid polymer thin film that exhibits good proton conductivity in a wet state. The electrolyte membrane is composed of, for example, an ion exchange membrane of a fluororesin. The catalyst layer includes a catalyst that promotes a chemical reaction between hydrogen and oxygen, and carbon particles that carry the catalyst. The electrolyte membrane and the catalyst layer are collectively referred to as a membrane electrode assembly (MEA (Membrane Electrode Assembly)).

Each gas diffusion layer is provided adjacent to the surface on the catalyst layer side. The gas diffusion layer is a layer that diffuses the reaction gas used for the electrode reaction along the surface direction of the electrolyte membrane, and is composed of a porous diffusion layer base material. As the base material for the diffusion layer, a porous base material having conductivity and gas diffusivity such as a carbon fiber base material, a graphite fiber base material, and a foam metal is used. The electrolyte membrane, catalyst layer, and gas diffusion layer are collectively referred to as a membrane electrode gas diffusion layer conjugate (MEGA (Membrane Electrode Gass-diffusion-layer Assembly)).

The resin sheet 20 is a frame-shaped resin member arranged around the power generator 10 including the membrane electrode assembly. The resin sheet 20 is preferably made of an insulating resin. In this embodiment, for example, polypropylene (PP) is used. However, as the resin sheet 20, various other resin members such as polyethylene naphthalate (PEN) and polyphenylene sulfide (PPS) can also be used. Flexural rigidity is preferably 0.002Pa · m ³ or more resin sheets 20, 0.004Pa · m ³ or more is more preferable. Further, the bending rigidity of the resin sheet 20 is preferably 0.09 Pa · m ³ or less, more preferably 0.04 Pa · m ^3. Further, in the present embodiment, the thickness of the resin sheet 20 is about 0.1 to 0.3 mm.

The pair of separators 40a and 40b are substantially rectangular members that sandwich the generator plate 25. The separators 40a and 40b are formed, for example, by press-molding a metal plate made of stainless steel, titanium, or an alloy thereof. In the present embodiment, the separator 40a and the separator 40b are collectively referred to as a separator 40.

The resin sheet 20 and the separator 40 have a manifold hole 30. Reaction gas or cooling water flows through the manifold hole 30. The separator 40 has a first recess 50a provided on each of the pair of short sides. Further, the resin sheet 20 has a second recess 50b at a position facing the first recess 50a when viewed from the stacking direction (z-axis direction) of the pair of separators 40 and the generator plate 25. The positions facing each other when viewed from the stacking direction mean that the positions in the plane direction (x-axis direction and y-axis direction) are substantially the same. In the present embodiment, the first recess 50a and the second recess 50b are collectively referred to as a recess 50. The recesses 50 may be provided on each of the pair of long sides.

FIG. 2 is a cross-sectional view when a plurality of fuel cell single cells 100 are stacked. A gasket 45 is provided between the separator 40a of one fuel cell single cell 100 and the separator 40b of the other fuel cell single cell 100 between adjacent fuel cell single cells 100. The gasket 45 is formed of, for example, silicone rubber. A cooling flow path through which cooling water flows from the manifold hole 30 is formed between adjacent fuel cell single cells 100, and this cooling flow path is sealed by a gasket 45.

As shown in FIG. 2, in the present embodiment, the ends of the resin sheet 20 on the long sides (x-axis direction) are extended from the ends of the separators 40a and 40b on the long sides (x-axis direction), respectively. There is. Similarly, the resin sheet 20 may be stretched more than the separator 40 at the end portion on the short side (y-axis direction).

FIG. 3 is an enlarged view of a portion A when the resin sheet 20 of FIG. 1 and the pair of separators 40 are joined. The fuel cell single cell 100 has a cell conversion reference unit 70 that penetrates the resin sheet 20 and the separator 40. The cellification reference unit 70 is a hole provided at a position opposite to each other in the stacking direction of the resin sheet 20 and the separator 40. A positioning pin is inserted into the cellization reference unit 70, for example, when the resin sheet 20 and the separator 40 are laminated. As a result, it is possible to prevent misalignment from occurring when the resin sheet 20 and the separator 40 are laminated to form the fuel cell single cell 100.

As shown in FIG. 3, the resin sheet 20 is hatched, and the second recess 50b extends from the first recess 50a to the inner peripheral side of the first recess 50a. In the present embodiment, the second concave portion 50b has a convex portion 60 on the side L1 extending in the x-axis direction on the −y axis side of the inner circumference of the second concave portion 50b. The convex portion 60 is formed of the same member as the resin sheet 20. The convex portion 60 has a lower bending rigidity than the portion of the side L2 of the opposite second concave portion 50b.

FIG. 4 is an explanatory diagram of an example in which the fuel cell single cells 100 of the present embodiment are stacked. FIG. 4 will be described with reference to an enlarged view of a portion A shown in FIG. In the present embodiment, the fuel cell single cell 100 is guided and laminated by using the laminated rail 80. The laminated rail 80 is also referred to as a "guide member". In the example of FIG. 4, the laminated rail 80 is a long member having a rectangular cross section. By fitting the laminated rail 80 into the recess 50 of the fuel cell single cell 100, it is possible to suppress the occurrence of misalignment when the fuel cell single cell 100 is laminated. The laminated rail 80 may be a fastening member.

As shown in FIG. 4, when the laminated rail 80 is fitted into the concave portion 50, the convex portion 60 of the fuel cell single cell 100 receives a force F from the laminated rail 80 in the arrow direction, and the opposite side L2 is the laminated rail. Pressed against 80. Therefore, without pressing the fuel cell single cell 100 against the laminated rail 80 by applying an external force, the space between the laminated rail 80 and the recess 50, more specifically, the side L2 of the laminated rail 80 and the second recess 50b. It is possible to suppress the formation of a gap between them. Further, since the convex portion 60 flexes flexibly and is not easily plastically deformed, the laminated rail 80 can be smoothly slid.

According to the fuel cell single cell 100 of the present embodiment described above, the laminated rail inserted into the first concave portion 50a when the convex portion 60 provided in the second concave portion 50b and the plurality of fuel cell single cells are laminated. The contact with the 80 regulates the position of the fuel cell single cell 100 with respect to the laminated rail 80. Since the convex portion 60 is provided in the second concave portion 50b of the resin sheet 20, the work at the time of laminating can be simplified as compared with the conventional case. Therefore, the complexity of the work can be reduced.

B. Other embodiments:
FIG. 5 is an enlarged view of a portion A when the resin sheet 20 of FIG. 1 and the pair of separators 40 are joined in another embodiment. In the above embodiment, only one convex portion 60 is provided on the side L1 of the second concave portion 50b in the x-axis direction. Instead, as shown in FIG. 5, a plurality of convex portions 60x may be provided on the side L1 of the second concave portion 50b. Further, the convex portion 60y may be provided on the side L3 of the second concave portion 50b. The convex portion 60 may be provided on at least one side of the second concave portion 50b, and may not be provided on the side L1.

FIG. 6 is an enlarged view of a portion A when the resin sheet 20 of FIG. 1 and the pair of separators 40 are joined in still another embodiment. In the above embodiment, the first concave portion 50a at the position corresponding to the second concave portion 50b where the convex portion 60 is provided is not provided at all. Instead, as shown in FIG. 6, the first concave portion 50a at a position corresponding to the second concave portion 50b provided with the convex portion 60 may be provided with the convex portion 60a.

FIG. 7 is an enlarged view of a portion A when the resin sheet 20 of FIG. 1 and the pair of separators 40 are joined in still another embodiment. In the embodiments of FIGS. 3 to 6, the recess 50 has a substantially rectangular shape having sides. Instead, as shown in FIG. 7, the recess 51 may have an arc shape. As can be understood from these embodiments, it is preferable that the convex portion 60 is provided in at least a part of the concave portion 50 (or 51) of the resin sheet 20.

The present invention is not limited to the above-described embodiment, and can be realized with various configurations within a range not deviating from the gist thereof. For example, the technical features in the embodiments corresponding to the technical features in each form described in the column of the outline of the invention are for solving the above-mentioned problems or for achieving a part or all of the above-mentioned effects. In addition, it is possible to replace or combine them as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be appropriately deleted.

10 ... Generator 20 ... Resin sheet 25 ... Generator plate 30 ... Manifold holes 40, 40a, 40b ... Separator 45 ... Gasket 50, 51 ... Recess 50a ... First recess 50b ... Second recess 60, 60a, 60x, 60y ... Convex part 70 ... Cellification reference part 80 ... Laminated rail 100 ... Fuel cell single cell L1, L2, L3 ... Side

Claims (1)

A fuel cell single cell for forming a fuel cell stack.
A generator plate having a generator including a membrane electrode assembly and a frame-shaped resin sheet bonded around the generator.
A pair of substantially rectangular separators are provided so as to sandwich the generator plate.
The pair of separators have first recesses provided on a pair of short sides or a pair of long sides, respectively.
The resin sheet extends toward the inner peripheral side of the first recess from the first recess at a position facing the first recess when viewed from the stacking direction of the pair of separators and the generator plate. Has a second recess that is
A fuel cell single cell in which a convex portion is provided on at least a part of a pair of surfaces connected to an open end of the second concave portion, which is the inner circumference of the second concave portion.

Images