JP2019075247A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently suppress bending of a laminated body. SOLUTION: A plurality of unit cells 10 are stacked, and a unit body 10 in which a unit cell 10a on one end side of the plurality of unit cells 10 is positioned above a unit cell 10b on the other end side in the gravity direction, and a layered body. The outer peripheral member 16 provided to face the side surface 24 of the laminated body 12 along the laminating direction, and the side surface 24 of the laminated body 12 provided between the side surface 24 of the laminated body 12 and the outer peripheral member 16 so as to be assembled to the outer peripheral member 16. And a support member 18 that is pressed to the side to support the stacked body 12, and the support member 18 has a larger force for supporting the stacked body 12 in the direction of gravity higher than the center of the stacked body 12 in the stacking direction. Thus, the fuel cell stack provided between the side surface of the laminate 12 and the outer peripheral member 16. [Selection diagram] Figure 1

Description

  The present invention relates to a fuel cell stack.

  There is known a fuel cell stack having a stack structure in which unit cells having an electrolyte membrane and electrodes sandwiching the electrolyte membrane are stacked. In the fuel cell stack, a force applied from the outside may cause a laminate in which a plurality of single cells are stacked to be bent, which may cause a gap between the single cells. Then, in order to control the gap between single cells, a configuration is known in which a gap adjusting mechanism is provided to adjust the gap between the stacked body in which a plurality of single cells are stacked and the case for storing the stacked body (for example, , Patent Document 1).

JP 2005-71869 A

  In patent document 1, the gap adjustment mechanism is provided at equal intervals in the stacking direction of the plurality of unit cells to suppress the deviation between the unit cells. However, the improvement is achieved in that the bending of the laminate is efficiently suppressed with respect to a laminate in which a plurality of unit cells are stacked and the unit cell on one end side is positioned above the unit cell on the other end side in the gravity direction. There is room for

  This invention is made in view of the said subject, and it aims at suppressing a bending of a laminated body efficiently.

  In the present invention, a stacked body in which a plurality of single cells are stacked, and a single cell on one end side of the plurality of single cells is positioned above the single cell on the other end side in the gravity direction, and a stacking direction of the stacked body Between the outer peripheral member provided opposite to the side surface along the side, the side surface of the laminate and the outer peripheral member, and assembled by being attached to the outer peripheral member, and pressed against the side surface of the laminate; A supporting member for supporting the laminated body, and the supporting member is provided with a side surface of the laminated body such that a force for supporting the laminated body is larger toward a gravity direction upper side than a center in the laminated direction of the laminated body. It is a fuel cell stack provided between the outer peripheral member.

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

FIG. 1 is a transparent side view of a fuel cell stack according to a first embodiment. 2 (a) is a transparent perspective view of the fuel cell stack according to Embodiment 1, and FIG. 2 (b) and FIG. 2 (c) are cross-sectional views at the corners of the laminate. FIG. 3 is a perspective view of the support member. FIG. 4 (a) is a see-through side view of a fuel cell stack according to a comparative example, and FIG. 4 (b) is a view for explaining problems that occur in the fuel cell stack according to the comparative example. FIG. 5 is a transparent perspective view of a fuel cell stack according to a modification of the first embodiment. 6 (a) is a transparent side view of a fuel cell stack according to a second embodiment, and FIG. 6 (b) is a transparent side view of a fuel cell stack according to a modification of the second embodiment. FIG. 7 is a transparent side view of a fuel cell stack according to a third embodiment. FIG. 8 is a transparent side view of a fuel cell stack according to a fourth embodiment.

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

  FIG. 1 is a transparent side view of a fuel cell stack according to a first embodiment. As illustrated in FIG. 1, the fuel cell stack 100 according to the first embodiment includes a stack 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 stacked body 12 is formed by stacking a plurality of single cells 10 in the direction of gravity. That is, the unit cell 10a on one end side of the plurality of unit cells 10 is positioned above the unit cell 10b on the other end side in the direction of gravity. In addition, as long as the single cell 10a is positioned above the single cell 10b in the direction of gravity, the stacking direction of the stacked body 12 is not limited to the case where the direction of gravity completely coincides with the direction of gravity. It may be

  The unit cell 10 is a polymer electrolyte fuel cell that receives power from a fuel gas (for example, hydrogen) and an oxidant gas (for example, air) as a reaction gas to generate electric power. The single cell 10 includes a pair of separators and a membrane electrode gas diffusion layer assembly (MEGA). The pair of separators are formed by members having gas barrier properties and electron conductivity, and form a fuel gas flow path through which the fuel gas supplied to the MEGA flows and an oxidant gas flow path through which the oxidant gas flows.

  MEGA includes a membrane electrode assembly (MEA: Membrane Electrode Assembly) including an electrolyte membrane and a pair of catalyst layers disposed on both sides of the electrolyte membrane. The electrolyte membrane is a solid polymer membrane formed of a fluorocarbon resin material or a fluorocarbon resin material having a sulfonic acid group, and has good proton conductivity in a wet state. One pair of catalyst layers includes carbon particles supporting a catalyst for promoting an electrochemical reaction, and an ionomer having a sulfonic acid group and being a solid polymer and having good proton conductivity in a wet state. A pair of gas diffusion layers are disposed on both sides of the MEA. The MEGA is formed by the MEA and the pair of gas diffusion layers. The pair of gas diffusion layers is formed by a member having gas permeability and electron conductivity.

  The end plate 14 is provided on both sides of the laminate 12 in the stacking direction. The end plate 14 presses the stacked body 12 in the stacking direction to bring the single cells 10 into close contact with each other. The end plate 14 is formed of, for example, a metal such as stainless steel or an aluminum alloy. A terminal for taking out the electric power generated by the fuel cell to the outside, an insulator for insulating the single cell 10 and the end plate 14 or the like may be provided between the end plate 14 and the laminate 12.

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

  The support member 18 is assembled to the outer peripheral member 16 between the side surface 24 of the laminate 12 and the outer peripheral member 16. The support member 18 is provided closer to the upper side in the direction of gravity than the central line 30 obtained by dividing the laminate 12 into two in the stacking direction. That is, when the upper end in the gravity direction of the laminate 12 is one end 50 and the lower end in the gravity direction is the other end 52, the support member 18 is closer to the one end 50 of the laminate 12 than the central line 30 of the laminate 12. It is provided close to In other words, the central line 32 obtained by dividing the support member 18 in the laminating direction of the laminate 12 is closer to one end 50 of the laminate 12 than the central line 30 of the laminate 12. As an example, the length in the stacking direction of the stack 12 of the support member 18 is 30 mm, and the center line 32 of the support member 18 is shifted 15 mm toward the one end 50 of the stack 12 than the center line 30 of the stack 12 There is. The support member 18 is pressed to 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.

  2 (a) is a transparent perspective view of the fuel cell stack according to Embodiment 1, and FIG. 2 (b) and FIG. 2 (c) are cross-sectional views at the corners of the laminate. FIG.2 (b) is sectional drawing in the area | region in which the supporting member was provided among the corner | angular parts of a laminated body, FIG.2 (c) is sectional drawing in the area | region in which the supporting member is not provided. . As shown in FIG. 2A, the support member 18 has an L-shaped shape, and is provided at four corner portions of the side surface 24 of the laminate 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 a resin (polypropylene or the like). The metal portion 40 is provided to cover the elastic portion 42. Therefore, the elastic portion 42 of the support member 18 abuts on the side surface 24 of the laminate 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, the length L, and the height H of the support member 18 are, for example, 30 mm. The support member 18 may be formed of only the metal portion 40 or may be formed of only the elastic portion 42. Since the support member 18 includes the elastic portion 42, the elastic portion 42 can absorb the displacement when the outer peripheral member 16 is deformed, and the influence on the laminate 12 can be suppressed.

  As shown in FIG. 2B and FIG. 2C, the outer peripheral member 16 protrudes outward in the portion where the support member 18 is assembled as compared with the other portions. Thus, a space in which the support member 18 is provided between the side surface 24 of the laminate 12 and the outer peripheral member 16 is secured. The support member 18 is pressed against the side surface 24 of the laminate 12 by a fixing member 44 such as a screw provided on the outer peripheral member 16.

  Here, in describing the effects of the fuel cell stack of Example 1, the fuel cell stack of the comparative example will be described. FIG. 4 (a) is a see-through side view of a fuel cell stack according to a comparative example, and FIG. 4 (b) is a view for explaining problems that occur 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 stack 12 and the outer peripheral member 16. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  In the fuel cell stack 500 of Comparative Example 1, a plurality of single cells 10 are stacked in the direction of gravity to form a stack 12. Therefore, for example, when an automobile equipped with the fuel cell stack 500 accelerates or decelerates or collides with another automobile etc., as shown in FIG. 4B, the inertial force in the direction crossing the stacking direction of the stack 12 Will work on the stack 12. The inertial force may cause the laminate 12 to bend, and when this deflection is large, misalignment may occur between the single cells 10. The deflection of the laminate 12 is more likely to occur on one end 50 side (upper side in the gravity direction) of the laminate 12 than the central line 30 obtained by dividing the laminate 12 in the laminating direction. This is due to the following reasons.

  That is, in the multilayer body 12 in which a plurality of single cells 10 are stacked in the direction of gravity, the weight of the single cell 10 on the upper side in the direction of gravity is applied to the single cell 10 closer to the lower side in the direction of gravity. For this reason, the unit cell 10 on the lower side in the direction of gravity of the laminate 12 has a compressive load larger than that of the unit cell 10 on the upper side in the direction of gravity. When a force in a direction intersecting the stacking direction of the stack 12 is applied to the stack 12, the gas diffusion layer having a relatively low rigidity in the single cell 10 is deformed, and this deformation causes the stack 12 to bend. . The deformation of the unit cell 10 is unlikely to occur in the unit cell 10 on the lower side in the direction of gravity of the laminate 12 to which a large compressive load is applied, and is likely to occur in the unit cell 10 on the upper side of the laminate 12 in the direction of gravity. . Therefore, when a force in a direction intersecting the stacking direction of the stacked body 12 is applied to the stacked body 12, the upper side in the gravity direction of the stacked body 12 is more easily bent than the lower side in the gravity direction, and the amount of deformation tends to be large. From such a reason, as shown in FIG. 4B, when an inertial force in a direction intersecting the stacking direction of the stacked body 12 is applied to the stacked body 12, one end of the stacked body 12 than the central line 30 of the stacked body 12 Deflection easily occurs 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, between the side surface 24 of the laminate 12 and the outer peripheral member 16, the support is pressed against the side surface 24 of the laminate 12 to support the laminate 12. A member 18 is provided. The supporting member 18 is provided closer to one end 50 side (upper side in the direction of gravity) of the central line 30 of the laminated body 12 than the central line 30, and the force supporting the laminated body 12 is greater than that of the central line 30 of the laminated body 12. It is larger on the upper side in the gravity direction than on the lower side in the gravity direction. That is, the force for supporting the stack 12 by the support member 18 is larger on the upper side in the direction of gravity than the center of the stack 12 in the stacking direction. Thus, the portion of the laminate 12 on the upper side in the direction of gravity, in which bending easily occurs, can be intensively supported by the support member 18, and the bending of the laminate 12 can be efficiently suppressed. For example, the bending of the laminate 12 is suppressed while reducing the number of parts of the support member 18 as compared to the case where the support members 18 are provided on the side surface 24 of the laminate 12 in a dotted manner throughout the laminate direction of the laminate 12 be able to.

  FIG. 5 is a transparent perspective view of a fuel cell stack according to a modification of the first embodiment. As shown in FIG. 5, in the fuel cell stack 110 according to the modification of the first embodiment, the support members 18 are provided not on the four corners of the side surface 24 of the stack 12 but on the flat portions of the side surfaces 24. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  The support member 18 may be provided at the corner of the side surface 24 of the laminate 12 as in the first embodiment, or provided at the flat portion of the side surface 24 of the laminate 12 as in the modification of the first embodiment. It is also good.

  6 (a) is a transparent side view of a fuel cell stack according to a second embodiment, and FIG. 6 (b) is a transparent side view of a fuel cell stack according to a modification 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 stack 12 at intervals in the stacking direction of the stack 12. The support member 18 positioned on the one end 50 side of the laminate 12 is from the trisection line 34 positioned on the one end 50 side of the laminate 12 among the three equally dividing lines 34 obtained by equally dividing the laminate 12 in the lamination direction. Are disposed close to one end 50 of the laminate 12. The supporting member 18 positioned on the other end 52 side of the laminate 12 is a portion of the lamination line 34 of the laminate 12 that is located on the other end 52 side of the lamination 12 of the laminate 12. It is disposed close to one end 50 side. That is, the central line 32 obtained by dividing the support member 18 into two in the stacking direction of the stacked body 12 is closer to the one end 50 side of the stacked body 12 than the three-part dividing line 34 of the stacked body 12. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  As shown in FIG. 6B, in the fuel cell stack 210 according to the modification of the second embodiment, the stack 12 on one end 50 side of the stack 12 than the central line 30 obtained by dividing the stack 12 into two in the stacking direction. Two supporting members 18 are provided on the side surface 24 of the housing 12 at intervals in the stacking direction of the stack 12. One support member 18 is provided in the stacking direction of the stacked body 12 on the side surface 24 of the stacked body 12 on the other end 52 side of the stacked body 12 with respect to the central line 30 of the stacked body 12. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  As in the second embodiment, the two support members 18 provided side by side in the stacking direction of the stacked body 12 are closer to one end 50 side (upper side in the gravity direction) of the three dividing lines 34 of the stacked body 12 It may be provided close to you. As in the modification of the second embodiment, a plurality of support members 18 are provided side by side in the stacking direction of the stacked body 12, and on one end 50 side (upper side in the gravity direction) of the stacked body 12 than the central line 30 of the stacked body 12. The number of support members 18 provided may be greater than the number of support members 18 provided on the other end 52 side (lower side in the direction of gravity). Even in these cases, since the force for supporting the laminate 12 by the support member 18 becomes larger toward the upper side in the direction of gravity than the center of the laminate 12 in the lamination direction, the deflection of the laminate 12 can be efficiently suppressed. it can.

  FIG. 7 is a transparent side view of a fuel cell stack according to a third embodiment. As shown in FIG. 7, in the fuel cell stack 300 of the third embodiment, supporting members 18 a and 18 b are provided on the side surface 24 of the stack 12 at intervals in the stacking direction of the stack 12. The supporting member 18a is disposed on the side surface 24 of the laminate 12 at a portion of 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 in the laminating direction. It is provided. The support member 18 b is provided on the side surface 24 of the laminate 12 at, for example, the portion of the trisection line 34 located on the other end 52 side of the trisection line 34 of the laminate 12. For example, the central line 32a obtained by dividing the support member 18a into two in the stacking direction of the stacked body 12 coincides with the trisection line 34 located on one end 50 side of the stacked body 12, and the supporting member 18b is stacked in the stacked direction of the stacked body 12 The central line 32 b divided into two at the same time coincides with the three-part dividing line 34 located on the other end 52 side of the laminate 12.

  The support member 18 a is longer than the support member 18 b in the stacking direction of the stack 12. For example, while the length in the stacking direction of the stacked body 12 is 30 mm in the support member 18 b, it is 50 mm in the support member 18 a. Therefore, the area in which the support member 18 a abuts on the side surface 24 of the laminate 12 is larger than the area in which the support member 18 b abuts on the side surface 24 of the laminate 12. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  As in the third embodiment, the area in which the support member 18 b provided on the other end 52 side (lower side in the gravity direction) of the laminated body 12 abuts on the laminated body 12 on the one end 50 side (upper side in the gravity direction) of the laminated body 12 A support member 18a may be provided that abuts on a larger area than that. Even in this case, since the force for supporting the laminate 12 by the support members 18a and 18b becomes larger toward the upper side in the direction of gravity than the center in the lamination direction of the laminate 12, the deflection of the laminate 12 is efficiently suppressed. Can.

  FIG. 8 is a transparent side view of a fuel cell stack according to a fourth embodiment. As shown in FIG. 8, in the fuel cell stack 400 according to the fourth embodiment, among the dividing lines 34 obtained by dividing the laminated body 12 in the laminating direction into three equally dividing lines 34, the equal dividing line 34 located on one end 50 side of the laminated body 12. The supporting member 20 is provided on the side surface 24 of the laminated body 12 at the position of. A support member 22 is provided on the side surface 24 of the laminate 12 at a portion of the trisection line 34 located on the other end 52 side of the laminate 12 among the trisection lines 34 of the laminate 12. For example, a central line 32 c obtained by dividing the support member 20 in the stacking direction of the laminate 12 and a central line 32 d obtained by dividing the support member 22 into two coincide with the trisection line 34 of the laminate 12. The support member 20 has a hardness (eg, high Vickers hardness) higher than that of the support member 22. For example, the support member 20 is formed of a metal such as stainless steel, and the support member 22 is formed of a resin such as polypropylene. The other configuration is the same as that of the first embodiment, and hence the description is omitted.

  As in the fourth embodiment, the support member 20 provided on one end 50 side (upper side in the gravity direction) of the laminate 12 is closer to the other end 52 side (lower side in the gravity direction) of the laminate 12 than the support member 22. It may be hard. Even in this case, since the force for supporting the laminate 12 by the support members 20 and 22 becomes larger at the upper side in the gravity direction than at the center in the lamination direction of the laminate 12, deflection of the laminate 12 is efficiently suppressed. Can.

  As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not limited to such a specific embodiment, and various modifications may be made within the scope of the present invention described in the claims. Changes are possible.

10 to 10 b Single-cell 12 laminated body 14 end plate 16 outer peripheral member 18 to 22 supporting member 24 side surface 30 central line 32 to 32 d central line 34 3 equal line 40 metal part 42 elastic part 44 fixing member 50 one end 52 other end 100 to 500 fuel cell stack

Claims (1)

A stacked body in which a plurality of single cells are stacked, and a single cell on one end side of the plurality of single cells is positioned above a single cell on the other side in a gravity direction.
An outer peripheral member provided opposite to a side surface along the stacking direction of the stacked body;
And a supporting member which is provided between the side surface of the laminate and the outer peripheral member and assembled to the outer circumferential member and is pressed against the side surface of the laminate to support the laminate.
The support member is provided between a side surface of the laminate and the outer peripheral member such that a force for supporting the laminate is larger on a gravity direction upper side than a center of the laminate in the lamination direction. Fuel cell stack.

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