JP6801624B2 - Fuel cell stack - Google Patents

Description

The present invention relates to a fuel cell stack.

A fuel cell stack in which a single cell having an electrolyte membrane and an electrode sandwiching the electrolyte membrane is laminated to form a stack structure is known. In the fuel cell stack, when a force is applied from the outside, the laminated body in which a plurality of single cells are laminated may be bent, and a gap may occur between the single cells. Therefore, in order to suppress the deviation between the single cells, a configuration is known in which a gap adjusting mechanism for adjusting the gap between the laminated body in which a plurality of single cells are laminated and the case for storing the laminated body is provided (for example). , Patent Document 1).

Japanese Unexamined Patent Publication No. 2005-71869

In Patent Document 1, gap adjusting mechanisms are provided at equal intervals in the stacking direction of a plurality of single cells to suppress deviation between the single cells. However, it is improved in that the deflection of the laminated body is efficiently suppressed with respect to the laminated body in which a plurality of single cells are laminated and the single cell on one end side is located on the upper side in the gravity direction with respect to the single cell on the other end side. There is room for.

The present invention has been made in view of the above problems, and an object of the present invention is to efficiently suppress bending of a laminated body.

In the present invention, a plurality of single cells are laminated, and the single cell on one end side of the plurality of single cells is located on the upper side in the gravity direction with respect to the single cell on the other end side, and the stacking direction of the laminated body. The outer peripheral member is provided so as to face the side surface along the side surface, and the outer peripheral member is assembled between the side surface of the laminated body and the outer peripheral member, and is pressed against the side surface side of the laminated body. The support member is provided with a support member for supporting the laminated body, and the support member is provided with a side surface of the laminated body so that the force for supporting the laminated body is biased upward in the gravity direction from the center of the laminated body. It is a fuel cell stack provided between the outer peripheral member and the outer peripheral member.

According to the present invention, the bending of the laminated body can be efficiently suppressed.

FIG. 1 is a perspective side view of the fuel cell stack according to the first embodiment. FIG. 2A is a perspective perspective view of the fuel cell stack according to the first embodiment, and FIGS. 2B and 2C are cross-sectional views at corners of the laminated body. FIG. 3 is a perspective view of the support member. FIG. 4A is a perspective side view of the fuel cell stack according to the comparative example, and FIG. 4B is a diagram illustrating a problem that occurs in the fuel cell stack according to the comparative example. FIG. 5 is a perspective perspective view of the fuel cell stack according to the modified example of the first embodiment. FIG. 6A is a perspective side view of the fuel cell stack according to the second embodiment, and FIG. 6B is a perspective side view of the fuel cell stack according to the modified example of the second embodiment. FIG. 7 is a perspective side view of the fuel cell stack according to the third embodiment. FIG. 8 is a perspective side view of the fuel cell stack according to the fourth embodiment.

Hereinafter, examples of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective side view of the fuel cell stack according to the first embodiment. As shown in FIG. 1, the fuel cell stack 100 of the first embodiment includes a laminated body 12, an end plate 14, an outer peripheral member 16, and a support member 18. The fuel cell stack 100 is mounted on, for example, a fuel cell vehicle or an electric vehicle.

The laminated body 12 is formed by laminating a plurality of single cells 10 in the direction of gravity. That is, the single cell 10a on one end side of the plurality of single cells 10 is located above the single cell 10b on the other end side in the direction of gravity. If the single cell 10a is located above the single cell 10b in the direction of gravity, the stacking direction of the laminated body 12 is not limited to the case where it completely coincides with the direction of gravity, and the direction is inclined diagonally with respect to the direction of gravity. It may be.

The single cell 10 is a polymer electrolyte fuel cell that generates electricity by being supplied with a fuel gas (for example, hydrogen) and an oxidant gas (for example, air) as reaction gases. The single cell 10 includes a pair of separators and a membrane electrode gas diffusion layer assembly (MEGA). The pair of separators is formed of a member having gas blocking property and electron conductivity, and forms a fuel gas flow path through which the fuel gas supplied to MEGA flows and an oxidant gas flow path through which the oxidant gas flows.

MEGA includes a membrane electrode assembly (MEA) comprising an electrolyte membrane and a pair of catalyst layers arranged on both sides of the electrolyte membrane. The electrolyte membrane is a solid polymer membrane formed of a fluorine-based resin material or a carbon-based resin material having a sulfonic acid group, and has good proton conductivity in a wet state. The pair of catalyst layers contains carbon particles carrying a catalyst for advancing an electrochemical reaction, and an ionomer which is a solid polymer having a sulfonic acid group and has good proton conductivity in a wet state. A pair of gas diffusion layers are arranged on both sides of the MEA. MEGA is formed by the MEA and a pair of gas diffusion layers. The pair of gas diffusion layers is formed by members having gas permeability and electron conductivity.

The end plate 14 is provided so as to sandwich the laminated body 12 from the laminating direction. The end plate 14 presses the laminated body 12 in the laminating direction to bring the single cells 10 into close contact with each other. The end plate 14 is made of a metal such as stainless steel or an aluminum alloy. In addition, between the end plate 14 and the laminated body 12, a terminal for taking out the electric power generated by the fuel cell and an insulator for insulating the single cell 10 and the end plate 14 may be provided.

The outer peripheral member 16 is provided so as to face the side surface 24 along the laminating direction of the laminated body 12. The outer peripheral member 16 is fixed to, for example, an end plate 14 and is provided so as to cover the side surface 24 of the laminated body 12. The outer peripheral member 16 is made of a metal such as stainless steel or an aluminum alloy.

The support member 18 is provided so as to be assembled to the outer peripheral member 16 between the side surface 24 of the laminated body 12 and the outer peripheral member 16. The support member 18 is provided closer to the upper side in the gravity direction than the central line 30 in which the laminated body 12 is bisected in the stacking direction. That is, when the upper end of the laminated body 12 in the gravity direction is one end 50 and the lower end in the gravity direction is the other end 52, the support member 18 is closer to one end 50 of the laminated body 12 than the central line 30 of the laminated body 12. It is provided near. In other words, the central line 32 obtained by dividing the support member 18 into two equal parts in the stacking direction of the laminated body 12 is closer to one end 50 side of the laminated body 12 than the central line 30 of the laminated body 12. As an example, the length of the laminated body 12 of the support member 18 in the stacking direction is 30 mm, and the central line 32 of the support member 18 is shifted by 15 mm from the central line 30 of the laminated body 12 toward one end 50 side of the laminated body 12. There is. The support member 18 is pressed toward the side surface 24 side of the laminate 12 by a fixing member 44 such as a screw provided on the outer peripheral member 16 to support the laminate 12.

FIG. 2A is a perspective perspective view of the fuel cell stack according to the first embodiment, and FIGS. 2B and 2C are cross-sectional views at corners of the laminated body. FIG. 2B is a cross-sectional view of the corner portion of the laminated body in the region where the support member is provided, and FIG. 2C is a cross-sectional view in the region where the support member is not provided. .. As shown in FIG. 2A, the support member 18 has an L-shape and is provided at four corners of the side surface 24 of the laminated body 12.

FIG. 3 is a perspective view of the support member. As shown in FIG. 3, the support member 18 is formed of, for example, a metal portion 40 such as stainless steel and an elastic portion 42 such as resin (polypropylene or the like). The metal portion 40 is provided so as to cover the elastic portion 42. Therefore, the elastic portion 42 of the support member 18 comes into contact with the side surface 24 of the laminated body 12. The thickness t1 of the metal portion 40 and the thickness t2 of the elastic portion 42 are, for example, 3 mm. The width W, length L, and height H of the support member 18 are, for example, 30 mm. The support member 18 may be formed only by the metal portion 40 or may be formed only by the elastic portion 42. Since the support member 18 includes the elastic portion 42, the displacement when the outer peripheral member 16 is deformed can be absorbed by the elastic portion 42, and the influence on the laminated body 12 can be suppressed.

As shown in FIGS. 2 (b) and 2 (c), the outer peripheral member 16 projects outward in the portion where the support member 18 is assembled as compared with the other portions. As a result, a space for providing the support member 18 is secured between the side surface 24 of the laminated body 12 and the outer peripheral member 16. The support member 18 is pressed against the side surface 24 of the laminated body 12 by a fixing member 44 such as a screw provided on the outer peripheral member 16.

Here, in explaining the effect of the fuel cell stack of the first embodiment, the fuel cell stack of the comparative example will be described. FIG. 4A is a perspective side view of the fuel cell stack according to the comparative example, and FIG. 4B is a diagram illustrating a problem that occurs in the fuel cell stack according to the comparative example. As shown in FIG. 4A, in the fuel cell stack 500 of the comparative example, the support member 18 is not provided between the side surface 24 of the laminated body 12 and the outer peripheral member 16. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

In the fuel cell stack 500 of Comparative Example 1, a plurality of single cells 10 are laminated in the direction of gravity to form a laminated body 12. Therefore, for example, when an automobile equipped with the fuel cell stack 500 accelerates or decelerates or collides with another automobile or the like, an inertial force in a direction intersecting the stacking direction of the laminated body 12 as shown in FIG. 4B. Will work on the laminate 12. Due to this inertial force, the laminated body 12 is bent, and when the bending is large, a deviation may occur between the single cells 10. The bending of the laminated body 12 is more likely to occur on one end 50 side (upper side in the gravity direction) of the laminated body 12 than the central line 30 in which the laminated body 12 is bisected in the stacking direction. This is due to the following reasons.

That is, in the laminated body 12 in which a plurality of single cells 10 are laminated in the gravity direction, the weight of the single cell 10 on the lower side in the gravity direction of the laminated body 12 is applied to the single cell 10 on the upper side in the gravity direction. Therefore, the single cell 10 on the lower side in the gravity direction of the laminated body 12 has a larger compressive load than the single cell 10 on the upper side in the gravity direction. When a force intersecting the stacking direction of the laminated body 12 is applied to the laminated body 12, the gas diffusion layer having a relatively low rigidity in the single cell 10 is deformed, and this deformation causes the laminated body 12 to bend. .. Deformation of the single cell 10 is unlikely to occur in the single cell 10 on the lower side in the gravity direction of the laminate 12 to which a large compressive load is applied, and is likely to occur in the single cell 10 on the upper side in the gravity direction of the laminate 12 having a small compressive load. .. Therefore, when a force in the direction intersecting the stacking direction of the laminated body 12 is applied to the laminated body 12, the upper side of the laminated body 12 in the gravity direction is more likely to bend than the lower side in the gravity direction, and the amount of deformation is likely to be large. For this reason, as shown in FIG. 4B, when an inertial force in a direction intersecting the stacking direction of the laminated body 12 is applied to the laminated body 12, one end of the laminated body 12 is more than the central line 30 of the laminated body 12. Deflection is likely to occur on the 50 side (upper side in the direction of gravity).

On the other hand, according to the first embodiment, as shown in FIG. 1, a support that supports the laminated body 12 by being pressed toward the side surface 24 side of the laminated body 12 between the side surface 24 of the laminated body 12 and the outer peripheral member 16. A member 18 is provided. The support member 18 is provided closer to one end 50 side (upper side in the gravity direction) of the laminated body 12 than the central line 30 of the laminated body 12, and the force for supporting the laminated body 12 is from the central line 30 of the laminated body 12. It is larger on the upper side in the direction of gravity than on the lower side in the direction of gravity. That is, the force of the support member 18 to support the laminated body 12 is biased to the upper side in the gravity direction from the center of the laminated body 12 in the stacking direction. As a result, the portion of the laminated body 12 on the upper side in the gravity direction where bending is likely to occur can be supported intensively by the support member 18, and the bending of the laminated body 12 can be efficiently suppressed. For example, as compared with the case where the support members 18 are scattered on the side surfaces 24 of the laminate 12 over the entire stacking direction of the laminate 12, the number of parts of the support members 18 is reduced and the bending of the laminate 12 is suppressed. be able to.

FIG. 5 is a perspective perspective view of the fuel cell stack according to the modified example of the first embodiment. As shown in FIG. 5, in the fuel cell stack 110 of the modified example of the first embodiment, the support member 18 is provided not on the four corners of the side surface 24 of the laminate 12, but on the flat portion of each side surface 24. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

The support member 18 may be provided at the corner of the side surface 24 of the laminated body 12 as in the first embodiment, or may be provided on the flat portion of the side surface 24 of the laminated body 12 as in the modified example of the first embodiment. May be good.

FIG. 6A is a perspective side view of the fuel cell stack according to the second embodiment, and FIG. 6B is a perspective side view of the fuel cell stack according to the modified example of the second embodiment. As shown in FIG. 6A, in the fuel cell stack 200 of the second embodiment, the support members 18 are provided on the side surface 24 of the laminated body 12 side by side at intervals in the stacking direction of the laminated body 12. The support member 18 located on the one end 50 side of the laminate 12 is from the three equal division line 34 located on the one end 50 side of the laminate 12 among the three equal division lines 34 in which the laminate 12 is divided into three equal parts in the lamination direction. Is also arranged closer to one end 50 side of the laminated body 12. The support member 18 located on the other end 52 side of the laminate 12 is a laminate 12 rather than the trisection line 34 located on the other end 52 side of the laminate 12 among the trisection lines 34 of the laminate 12. One end is arranged closer to the 50 side. That is, the central line 32 in which the support member 18 is bisected in the stacking direction of the laminated body 12 is closer to one end 50 side of the laminated body 12 than the trisecting line 34 of the laminated body 12. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

As shown in FIG. 6B, in the fuel cell stack 210 of the modified example of the second embodiment, the laminated body 12 is located at one end 50 side of the laminated body 12 with respect to the central line 30 in which the laminated body 12 is bisected in the stacking direction. On the side surface 24 of the above, two support members 18 arranged at intervals in the stacking direction of the laminated body 12 are provided. One support member 18 is provided on the side surface 24 of the laminated body 12 on the other end 52 side of the laminated body 12 with respect to the central line 30 of the laminated body 12 in the laminating direction of the laminated body 12. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

As in the second embodiment, the two support members 18 provided side by side in the stacking direction of the laminated body 12 are located on one end 50 side (upper side in the gravity direction) of the laminated body 12 with respect to the trisection line 34 of the laminated body 12. It may be provided close to each other. As in the modified example of the second embodiment, a plurality of support members 18 are provided side by side in the stacking direction of the laminated body 12, and one end 50 side (upper side in the gravity direction) of the laminated body 12 is provided with respect to the central line 30 of the laminated body 12. The number of the support members 18 provided may be larger than the number of the support members 18 provided on the other end 52 side (lower side in the direction of gravity). Even in these cases, the force of the support member 18 to support the laminated body 12 is biased to the upper side in the gravity direction from the center of the laminated body 12, so that the bending of the laminated body 12 can be efficiently suppressed. it can.

FIG. 7 is a perspective side view of the fuel cell stack according to the third embodiment. As shown in FIG. 7, in the fuel cell stack 300 of the third embodiment, support members 18a and 18b arranged at intervals in the stacking direction of the laminated body 12 are provided on the side surface 24 of the laminated body 12. The support member 18a is, for example, on the side surface 24 of the laminated body 12 at a position of the three equal divided lines 34 located on the one end 50 side of the laminated body 12 among the three equal divided lines 34 obtained by dividing the laminated body 12 into three equal parts in the stacking direction. It is provided. The support member 18b is provided on the side surface 24 of the laminated body 12, for example, at the position of the three equal divided lines 34 located on the other end 52 side of the laminated body 12 among the three equal divided lines 34 of the laminated body 12. For example, the central line 32a obtained by dividing the support member 18a into two equal parts in the stacking direction of the laminated body 12 coincides with the trisecting line 34 located on one end 50 side of the laminated body 12, and the support member 18b is divided into three equal parts in the stacking direction of the laminated body 12. The central line 32b bisected by the above coincides with the trisecting line 34 located on the other end 52 side of the laminated body 12.

In the stacking direction of the laminated body 12, the support member 18a is longer than the support member 18b. For example, the length of the laminated body 12 in the stacking direction is 30 mm for the support member 18b, whereas it is 50 mm for the support member 18a. Therefore, the area where the support member 18a abuts on the side surface 24 of the laminated body 12 is larger than the area where the support member 18b abuts on the side surface 24 of the laminated body 12. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

Area where the support member 18b provided on one end 50 side (upper side in the gravity direction) of the laminated body 12 and the other end 52 side (lower side in the gravity direction) of the laminated body 12 abuts on the laminated body 12 as in the third embodiment. A support member 18a that comes into contact with a larger area may be provided. Even in this case, the force of the support members 18a and 18b to support the laminated body 12 is biased to the upper side in the gravitational direction from the center of the laminated body 12, so that the bending of the laminated body 12 is efficiently suppressed. Can be done.

FIG. 8 is a perspective side view of the fuel cell stack according to the fourth embodiment. As shown in FIG. 8, in the fuel cell stack 400 of the fourth embodiment, the trisection line 34 located on one end 50 side of the laminate 12 among the trisection lines 34 obtained by dividing the laminate 12 into three equal parts in the stacking direction. A support member 20 is provided on the side surface 24 of the laminated body 12 at the above location. A support member 22 is provided on the side surface 24 of the laminated body 12 at a position of the three equal divided lines 34 located on the other end 52 side of the laminated body 12 among the three equal divided lines 34 of the laminated body 12. For example, the central line 32c in which the support member 20 is bisected in the laminating direction of the laminated body 12 and the central line 32d in which the support member 22 is bisected in the laminating direction coincide with the trisecting line 34 of the laminated body 12. The support member 20 has a higher hardness (for example, higher Vickers hardness) than the support member 22. For example, the support member 20 is made of a metal such as stainless steel, and the support member 22 is made of a resin such as polypropylene. Since other configurations are the same as those in the first embodiment, the description thereof will be omitted.

As in the fourth embodiment, the support member 20 provided on one end 50 side (upper side in the gravity direction) of the laminated body 12 is from the support member 22 provided on the other end 52 side (lower side in the gravity direction) of the laminated body 12. May be hard. Even in this case, the force of the support members 20 and 22 to support the laminated body 12 is biased to the upper side in the gravitational direction from the center of the laminated body 12, so that the bending of the laminated body 12 is efficiently suppressed. Can be done.

Although the examples of the present invention have been described in detail above, the present invention is not limited to such specific examples, and various modifications and modifications are made within the scope of the gist of the present invention described in the claims. It can be changed.

10 to 10b Single cell 12 Laminated body 14 End plate 16 Outer peripheral member 18 to 22 Support member 24 Side surface 30 Central line 32 to 32d Central line 34 3 Equal division line 40 Metal part 42 Elastic part 44 Fixing member 50 One end 52 The other end 100 to 500 fuel cell stack

Claims (1)

A laminated body in which a plurality of single cells are laminated, and the single cell on one end side of the plurality of single cells is located above the single cell on the other end side in the direction of gravity.
An outer peripheral member provided so as to face the side surface of the laminated body along the laminating direction,
A support member that is assembled and provided on the outer peripheral member between the side surface of the laminated body and the outer peripheral member and is pressed against the side surface side of the laminated body to support the laminated body is provided.
The support member is provided between the side surface of the laminated body and the outer peripheral member so that the force for supporting the laminated body is biased toward the upper side in the gravity direction with respect to the center of the laminated body. Fuel cell stack.

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