JP2010140870A - Fuel battery cell stack, and end plate for fuel battery - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an end plate for a fuel battery on which a fuel battery cell can be stacked easily. <P>SOLUTION: The insulator 60 is provided with a flat surface section 61 in an approximately rectangular plate state that is orthogonal to the stacked direction of the fuel cell stack 20. Wall surfaces 62 to 65 formed toward the end plate 130 side are provided over the whole outer edge section of the insulator 60. Furthermore, wall surfaces 62 to 65 are provided with stacking reference surfaces 71 to 76. The end plate 130 is provided with stacking reference surfaces 141 to 146 in positions corresponding to the stacking reference surfaces 71 to 76. The stacking reference surfaces 141 to 146 have cut end sections on the insulator 60 side and the stacking reference surfaces 71 to 76 and the stacking reference surfaces 141a to 146a which are portions not cut among the stacking reference surfaces 141 to 146 respectively become one plane when the insulator 60 and the end plate 130 are stacked. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell end plate.

  A fuel cell is configured, for example, by laminating a plurality of power generation bodies in which an electrolyte membrane / electrode assembly, a gas diffusion layer, a separator, and the like are laminated, and fastening a fuel cell stack sandwiched between terminals, insulators, and end plates on both sides. The In such a fuel cell stack, in order to reduce the thickness of the insulator while ensuring an insulation distance, the shape of the insulator is a shape in which a wall surface is formed on the outer edge of the plate-like flat portion toward the adjacent end plate side. In this case, the end plate is laminated by being fitted into a recess formed by the planar portion and the wall surface of the insulator. However, since the outer shape of the insulator is larger than that of the end plate, it is not easy to stack the fuel cell stack along one stacking reference plane.

JP-A-10-189025

  In view of at least a part of the above problems, the problem to be solved by the present invention is to facilitate stacking of fuel cell stacks.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1] A fuel cell stack, in which a plurality of power generators are stacked, a current collector plate disposed at both ends of the power generator stack in the stacking direction, A plate-like plane portion disposed outside the stacking direction and orthogonal to the stacking direction; a wall surface formed on an outer edge of the plane portion in a direction opposite to the current collector plate; and the wall surface An end plate that is fitted and disposed in a recess formed by an insulator having a first laminated reference surface recessed inward, and the flat portion and the wall surface, and other than the laminated surface of the end plate Of the side surface of the first laminated reference plane is recessed at the inner side at a position corresponding to the first laminated reference plane, and the bottom surface at the end of the recess is at least a depth greater than the wall height of the wall surface of the first laminated reference plane, and at least In the first laminated reference plane And an end plate having a second lamination reference plane cut out at a depth equal to or greater than the thickness of the wall surface, and the second lamination reference plane is arranged in the cutout portion. A fuel cell stack that is flush with the reference plane.

  In the fuel cell stack having such a configuration, the end plate has a second laminated reference surface cut out, and the first laminated reference surface of the insulator is disposed in the cutout portion. The not-cut surface is flush with the first laminated reference surface. Therefore, the constituent members of the fuel cell stack can be easily stacked along the stacking reference plane that is flush with each other. As a result, the jig used for stacking can be simplified.

  In addition to the configuration as a fuel cell stack, the present invention can also be realized as an end plate for a fuel cell according to Application Example 2.

Application Example 2 An end plate for a fuel cell, which is a laminated reference surface that is recessed inwardly on a side surface in the thickness direction of the end plate, and a bottom surface of the laminated reference surface is formed at an end of the laminated reference surface An end plate for a fuel cell having a laminated reference surface having a notched portion.

A. Example:
Examples of the present invention will be described.
A-1. Schematic configuration of the fuel cell stack 20:
A schematic configuration of a fuel cell stack 20 as an embodiment of the present invention is shown in FIG. The fuel cell stack 20 is a polymer electrolyte fuel cell, in which a plurality of power generators 30 are stacked and sandwiched between terminals 42 and 44, insulators 50 and 60, and end plates 100 and 130 disposed at both ends in the stacking direction. Composed.

  The power generator 30 includes a gas diffusion layer on both surfaces of an electrolyte membrane / electrode assembly including a cathode electrode and an anode electrode on the surface of an electrolyte membrane which is a thin film of a solid polymer material exhibiting good proton conductivity in a wet state. Further, the flow path member and the separator are laminated (not shown).

  The terminals 42 and 44 are current collector plates that extract electricity generated by the power generator 30 from an output terminal (not shown). The terminals 42 and 44 can be formed using various conductive members, but in this embodiment, copper members formed in a plate shape are used.

  The insulators 50 and 60 are insulating members that insulate the terminals 42 and 44 from the end plates 100 and 130. The insulators 50 and 60 can be formed using various insulating members. In this embodiment, the insulators 50 and 60 are made of nylon and EVOH (ethylene / vinyl alcohol copolymer resin). In the present embodiment, the insulator 50 has a plate-like shape, but the insulator 60 has a wall surface portion folded to the terminal 44 side or the insulator 60 side in addition to the plate-like shape. In this embodiment, the shape of the insulator 60 is formed by vacuum forming. Details of the shape will be described later. The insulators 50 and 60 are provided with a stacking reference plane for stacking the members of the fuel cell stack 20, but are not shown in FIG.

  The end plates 100 and 130 are members for pressurizing the fuel cell stack 20 from both ends in the stacking direction. The end plates 100 and 130 can be formed of various metal members having corrosion resistance and rigidity. In the present embodiment, the end plates 100 and 130 are made of stainless steel. Although the end plate 130 has the same thickness in the stacking direction as the end plate 100, the end plate 130 is inserted inside the wall surface of the insulator 60 described above. It appears that the thickness of 130 is smaller than the thickness of the end plate 100. The actual end portion of the end plate 130 on the insulator 60 side is a portion indicated by a dotted line. Note that the end plates 100 and 130 include a stacking reference surface for stacking the members of the fuel cell stack 20, but are not shown in FIG.

  The fuel cell stack 20 is fastened and fastened in the stacking direction by fastening members 111 to 116 including fastening shafts and bolts. Specifically, the end plates 100 and 130 and the insulators 50 and 60 have six through holes communicating with each other on the outer periphery thereof, and the terminals 42 and 44 and the power generator 30 correspond to the through holes. A recess is provided at the position. The fuel cell stack 20 is fastened through the end plates 100 and 130 by passing the fastening shafts of the fastening members 111 to 116 through such through holes and recesses, pressurizing them in the stacking direction and fixing them with bolts.

  Further, the end plate 100 has holes 121 and 122 for supplying and discharging hydrogen as a fuel gas to and from the power generation body 30, and holes 123 and 124 for supplying and discharging air as an oxidizing gas to and from the power generation body 30. Holes 125 and 126 for supplying and discharging the cooling water to and from the power generator 30 are provided. These holes communicate with holes (not shown) provided in the insulator 50, the terminal 42, and the power generation body 30 to form a manifold, and serve to circulate hydrogen, air, and cooling water. The hydrogen, air, and cooling water supplied to the fuel cell stack 20 are supplied from the end plate 100 side, folded back by the power generator 30 adjacent to the terminal 44, and discharged from the end plate 100 side. And the end plate 130 does not have the above-mentioned hole.

A-2. Insulator 60 shape:
The overall shape of the insulator 60 described above is shown in FIG. In the insulator 60 shown in the drawing, the terminal 44 is stacked on the upper side of the drawing and the end plate 130 is stacked on the lower side of the drawing in the stacked positional relationship shown in FIG. As shown in the drawing, the insulator 60 includes a substantially rectangular plate-shaped flat portion 61 that is orthogonal to the stacking direction of the fuel cell stack 20. The insulator 60 includes wall surfaces 62 to 65 formed toward the end plate 130 (the lower side in FIG. 2) over the entire outer edge portion.

  Insulator 60 is provided with openings 91 to 96 at the four corners of the substantially rectangular shape at the outer edge and the central part of the long side. Wall surfaces 81 to 86 are formed on the outer edge portions of the openings 91 to 96 toward the terminal 44 side over the entire outer edge portion. The openings 91 to 96 are through holes through which the fastening shafts of the fastening members 111 to 116 described above are passed. The wall surfaces 81 to 86 are formed integrally with the wall surfaces 62 to 65 formed on the outer edge portion of the insulator 60, but are described here as virtually separated wall surfaces for convenience of explanation.

  Moreover, the insulator 60 has the recessed part dented inward in the wall surfaces 62-65. The bottom surface of the recess is referred to as a stacking reference surface 71-76. The stacking reference surfaces 71 to 76 are provided to align the stacking surfaces when the members of the fuel cell stack 20 are stacked. The stacking reference surfaces 71 to 76 correspond to the first stacking reference surface of the claims.

A-3. End plate 130 shape:
The overall shape of the end plate 130 described above is shown in FIG. In the illustrated end plate 130, the insulator 60 is stacked on the upper side of the drawing in the stacked positional relationship shown in FIG. 1. As shown in the figure, the end plate 130 has a substantially rectangular plate shape smaller than the inner dimension of the insulator 60 shown in FIG. Further, the end plate 130 includes through holes 131 to 136 through which the fastening shafts of the fastening members 111 to 116 described above are passed at positions corresponding to the openings 91 to 96 of the insulator 60.

  Further, the end plate 130 has a concave portion recessed inward on a side surface other than the laminated surface. The bottom surface of the concave portion is referred to as a laminated reference surface 141 to 146. The stacking reference surfaces 141 to 146 are provided so as to align the stacking surfaces when the members of the fuel cell stack 20 are stacked by being flush with the stacking reference surfaces 71 to 76 described above. Therefore, the stacking reference surfaces 141 to 146 are provided at positions corresponding to the stacking reference surfaces 71 to 76 of the insulator 60. Further, since the end plate 130 is fitted to the inner dimension of the insulator 60, the width of the laminated reference surfaces 141 to 146 is larger than the laminated reference surfaces 71 to 76.

  The laminated reference surfaces 141 to 146 have a shape in which an end portion on the insulator 60 side is notched. In this embodiment, the notch depth (y direction in FIG. 3) is formed to be equal to the wall height of the laminated reference surfaces 71 to 76 (wall surfaces 62 to 65). Further, the notch depth (z direction in FIG. 3) is formed to be equal to the thickness of the wall surfaces 62 to 65. For ease of explanation, “a” is added to the reference of the stacking reference surface in the not-cut portion of the stacking reference surfaces 141 to 146, and the stacking reference is added to the notched portion. It is expressed by adding “b” to the code of the surface. For example, the lamination reference surface 142 includes a lamination reference surface 142a that is not cut out and a lamination reference surface 142b that is cut out. The stacking reference surfaces 141 to 146 correspond to the second stacking reference surface of the claims.

A-4. Laminated state of insulator 60 and end plate 130:
FIG. 4 shows a stacked state of the insulator 60 and the end plate 130 on the cut surface based on the cutting instruction line AA shown in FIGS. As shown in the drawing, the insulator 60 is laminated on the end plate 130 side so that the end plate 130 fits into a recess formed by the flat surface portion 61 and the wall surfaces 64 and 65 formed toward the end plate 130 side. The The insulator 60 is laminated together with the terminal 44 and the power generator 30 at the same level as the inner dimensions of the wall surfaces 64 and 65 on the terminal 44 side. In this embodiment, the thickness of the insulator 60 is 2 mm, and the length of the wall surfaces 63 and 65 in the stacking direction is the insulation distance ID1 (8 mm in this embodiment) necessary for insulating the end plate 130 and the terminal 44 from each other. It was. As described above, the insulator 60 has a flat surface portion while ensuring an insulation distance by making the insulation distance ID2 (creeping distance) between the terminal 44 and the end plate 130 equal to or greater than the necessary insulation distance ID1 by the wall surfaces 63 and 65. The thickness of 61 in the stacking direction can be reduced.

  Further, FIG. 5 shows a stacked state of the insulator 60 and the end plate 130 on the cut surface based on the cutting instruction line BB shown in FIGS. As shown in the figure, the insulator 60 ends on the end plate 130 side in a recess formed by the flat surface portion 61 and the wall surfaces 63 and 65 formed toward the end plate 130 side, similarly to the AA cross section described above. The plates 130 are stacked so as to fit. Further, the insulator 60 is laminated on the terminal 44 side so that the terminal 44 and the power generator 30 are fitted in a recess formed by the flat surface portion 61 and the wall surfaces 81 and 82 formed toward the terminal 44 side. . Insulating sheets 151 and 152 are provided in the gap between the wall surface 81 and the power generation body 30 and the fastening member 111 and in the gap between the wall surface 82 and the power generation body 30 and the fastening member 116, respectively. In such a laminated state, the insulation distance ID3 (creeping distance) between the terminal 44 and the power generating body 30 and the end plate 130 is set to be equal to or greater than the necessary insulation distance ID1 by the wall surfaces 81 and 82 even in the vicinity of the openings 91 and 92. can do.

  As described above, the insulator 60 can reduce the thickness of the insulator while ensuring a sufficient insulation distance between the power generation body 30 and the terminal 44 and the end plate 130. As a result, the fuel cell stack 20 can be made compact.

  Further, FIG. 6 shows a stacked state of the insulator 60 and the end plate 130 on the cut surface based on the cutting instruction line CC shown in FIGS. The cut surface is a cross section including the lamination reference surface 72 of the insulator 60 and the lamination reference surface 142 of the end plate 130. As shown in the drawing, on the wall surface 65 side that does not have the lamination reference surfaces 72 and 142, it is the same as the lamination state shown in FIG.

  On the other hand, on the side of the lamination reference surfaces 72 and 142, the insulator 60 and the end plate 130 are in contact with the inner dimension of the wall surface 63 and the lamination reference surface 142b, so that the wall surface 63 fits in the cutout portion of the lamination reference surface 142. Is laminated. At this time, the lamination reference surfaces 72 and 142a are flush with each other.

  A laminated state of the insulator 60 and the end plate 130 is shown in a perspective view in FIG. The hatched display portion in the figure shows the insulator 60. Also, the dotted line in the figure indicates the part of the outline of the end plate 130 that is blinded by the insulator 60, and the thick line in the figure indicates the part in which the outline of the insulator 60 and the outline of the end plate 130 appear to overlap. ing. As shown in the drawing, the end plate 130 is laminated so as to fit within the inner dimensions of the insulator 60 at portions other than the lamination reference surfaces 72 and 142. That is, the wall surface 63 of the insulator 60 projects outward from the end plate 130. On the other hand, it can be seen that in the portions of the stacking reference surfaces 72 and 142, the stacking reference surface 72 and the stacking reference surface 142a are in contact with each other at the end portions and are flush with each other. The reason why the stacking reference surface 72 and the stacking reference surface 142a are in contact with each other at this end is that the depth D of the cutout portion of the stacking reference surface 142 is equal to the wall height of the wall surface 63 as described above. .

  In addition, although description is abbreviate | omitted, it becomes the positional relationship similar to the lamination | stacking reference plane 72 and the lamination | stacking reference plane 142 which were mentioned also about the lamination | stacking reference planes 71 and 73-76 and the lamination | stacking reference planes 141 and 143-146.

  Since the fuel cell stack 20 having such a configuration includes cutout portions on the stacking reference surfaces 141 to 146, the stacking reference surfaces 71 to 76 of the insulator 60 are arranged in the cutout portions when the fuel cell stack 20 is stacked. By doing so, the stacking reference surfaces 71 to 76 and the stacking reference surfaces 142a to 146a can be flush with each other. Therefore, the constituent members of the fuel cell stack 20 can be easily laminated along the laminated reference plane that is flush with the other. As a result, the jig used for stacking can be simplified. In addition, since the end plate 130 is only cut out to the minimum necessary, a decrease in strength of the end plate 130 can be suppressed to a level that does not cause a problem.

B: Modification:
A modification of the above embodiment will be described.
B-1. Modification 1:
The shape of the insulator 60 is not limited to the shape shown in FIG. 2, and a wall surface formed toward the end plate 130 side is provided on at least a part of the outer edge portion of the flat surface portion 61, and the wall surface portion is further provided. Any shape may be used as long as the laminated reference surface is provided on the surface. For example, as shown in FIG. 8, it is good also as a shape which provided the wall surface 67 formed in the part of the plane part 61 toward the terminal 44 side, or the shape which does not have the wall surfaces 81-86 and 91-96. Also good.

  Similarly, the end plate 130 is not limited to the shape shown in FIG. 3, and may be any shape provided with a laminated reference surface provided with a notch of a predetermined shape. For example, in the shape of the end plate 130 shown in FIG. 3, it is good also as a shape which does not have the through-holes 131-136.

  Further, the number of reference planes of the insulator 60 and the end plate 130 is not limited to six as shown in the embodiment, and may be set as appropriate in consideration of the convenience of the stacking operation. For example, a configuration including a total of four stacking reference planes, one on each side of a substantially rectangular outer shape, or a configuration including a total of eight stacking reference planes, two on each side may be employed.

B-2. Modification 2:
In the above-described embodiment, only the insulator 60 of the insulators 50 and 60 constituting the fuel cell stack 20 has the shape shown in FIG. 2, and only the end plate 130 of the end plates 100 and 130 is shown in FIG. The reason is that the insulator 50 needs to be provided with holes communicating with the holes 121 to 126, and the sealing performance of the holes needs to be taken into consideration. The shape shown in FIG. 2 is adopted for the insulator 50 as well as the end plate 100 as long as the sealing member is suitably attached around these hole portions so as to ensure a sealing property. Alternatively, the shape shown in FIG. 3 may be adopted.

B-3. Modification 3:
In the above-described embodiment, the stacking reference surfaces 71 to 76 and the stacking reference surfaces 141a to 146a are in contact with each other at the end portions and are flush with each other. It is not always necessary to contact the surfaces 141a to 146a at the ends. For example, as shown in FIG. 9, there may be a gap C1 between the end portion of the stacking reference surface 72 and the end portion of the stacking reference surface 142a. That is, it is only necessary that the depth of the cutout portion of the stacking reference surface 142 is greater than the wall height of the wall surface 63. Moreover, in the above-mentioned embodiment, although the structure which the inner dimension of the wall surface 63 and the lamination | stacking reference plane 142b contacted was shown, these do not necessarily need to contact. For example, as shown in FIG. 9, there may be a gap C2 between the inner dimension of the wall surface 63 and the lamination reference surface 142b. That is, the depth of the cutout of the laminated reference surface 142 only needs to be larger than the thickness of the wall surface 63. Even in such a shape, the stacking reference surface 72 and the stacking reference surface 142a are flush with each other, so that the same effect as in the embodiment can be obtained.

  The embodiment of the present invention has been described above, but the present invention is not limited to such an example, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, the present invention is not limited to the polymer electrolyte fuel cell shown in the embodiments, but can be applied to various fuel cells such as a direct methanol fuel cell and a phosphoric acid fuel cell.

2 is an explanatory diagram showing a schematic configuration of a fuel cell stack 20. FIG. It is explanatory drawing which shows the shape of the insulator 60. FIG. It is explanatory drawing which shows the shape of the end plate 130. FIG. It is sectional drawing (AA cross section) which shows the lamination | stacking state of the insulator 60 and the end plate 130. FIG. It is sectional drawing (BB cross section) which shows the lamination | stacking state of the insulator 60 and the end plate 130. FIG. It is sectional drawing (CC cross section) which shows the lamination | stacking state of the insulator 60 and the end plate 130. FIG. It is a perspective view which shows the lamination | stacking state of the insulator 60 and the end plate 130. FIG. It is sectional drawing which shows the shape of the insulator 60 as a modification. It is sectional drawing which shows the lamination | stacking state of the insulator 60 and the end plate 130 as a modification.

Explanation of symbols

DESCRIPTION OF SYMBOLS 20 ... Fuel cell stack 30 ... Power generation body 42, 44 ... Terminal 50, 60 ... Insulator 61 ... Planar part 62-65, 67, 81-86 ... Wall surface 71-76, 141-146, 142a, 142b ... Stacking reference plane 91 ... 96 ... Opening part 100,130 ... End plate 111-116 ... Fastening member 121-126 ... Hole part 131-136 ... Through hole 151,152 ... Insulation sheet ID1-ID3 ... Insulation distance C1-C2 ... Gap

Claims (2)

A fuel cell stack,
A power generator stacking unit in which a plurality of power generators are stacked;
Current collector plates disposed at both ends in the stacking direction of the power generator stack,
A plate-shaped plane portion that is disposed outside the stacking direction of the current collector plate and is orthogonal to the stacking direction, and a wall surface that is formed on the outer edge of the plane portion in a direction opposite to the current collector plate side. And an insulator comprising a first laminated reference surface recessed inward on the wall surface;
An end plate that is fitted and disposed in a recess formed by the flat portion and the wall surface, and is located on an inner side at a position corresponding to the first stacking reference surface on a side surface other than the stacking surface of the end plate. The bottom surface at the end of the recess is at least a depth equal to or greater than the wall height of the wall surface at the first lamination reference plane, and at least a depth equal to or greater than the thickness of the wall surface at the first lamination reference plane. An end plate with a second laminated reference plane cut out,
The second stacking reference plane is flush with the first stacking reference plane disposed in the cutout portion. An end plate for a fuel cell,
A lamination reference surface that is recessed inwardly on the side surface in the thickness direction of the end plate, and is provided with a lamination reference surface having a notch formed by cutting out the bottom surface of the lamination reference surface at the end of the lamination reference surface. End plate for fuel cell.

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