JP6150040B2 - Fuel cell and fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell and a fuel cell stack.

  Conventionally, there has been proposed a fuel cell that can achieve both optimization of the performance of each cell when a fuel cell stack is configured and improvement in durability of the joint between the frame and the membrane electrode structure (patent) Reference 1).

  This fuel cell includes a membrane electrode structure having a frame around it, and two separators sandwiching the frame and the membrane electrode structure, and a gas seal is provided between the frame and the edges of each separator, It is a fuel battery cell which has each diffuser part which distribute | circulates the gas for reaction between a flame | frame and each separator. In the fuel cell, in the diffuser portion on either the cathode side or the anode side, at least one of the opposing surfaces of the frame and the separator is provided with a protrusion that contacts the counterpart side, The frame is separated from the separator in the diffuser portion on the other side. In addition, in the other fuel cell, in the diffuser portion on either the cathode side or the anode side, a protrusion that contacts the mating side is provided on at least one of the opposing surfaces of the frame and the separator, and the other side In the diffuser portion, an elastic body in contact with both is interposed between the frame and the separator. In still another fuel cell, an elastic body that is in contact with both of the diffuser portions on the cathode side and the anode side is interposed between the frame and the separator.

JP 2012-212560 A

  However, in the fuel cell described in Patent Document 1, it is difficult to provide a predetermined size protrusion on the frame or the separator or to insert a plurality of elastic bodies of a predetermined size between the frame and the separator. However, since there was a variation in accuracy, it was not sufficient to reduce the electrical contact resistance between the membrane electrode assembly and the separator and to suppress the frame breakage in the gas distribution part and the gas recovery part, and there was room for improvement.

  The present invention has been made in view of the above-described problems of the prior art. An object of the present invention is to provide a fuel cell and a fuel cell stack that can achieve both a reduction in electrical contact resistance between a membrane electrode assembly and a separator, and suppression of frame breakage in a gas distribution part and a gas recovery part. And

The inventors of the present invention have made extensive studies in order to achieve the above object. As a result, the inventors have found that the above object can be achieved by adopting any one of the following configurations (1) and ( 2 ), and have completed the present invention.

(1) In a predetermined fuel cell, the gas distribution part and the gas recovery part on both the anode side and the cathode side in the thickness direction are in contact with one of the frame and each separator and formed at the base part to constitute a spring function part And a displacement absorbing member for absorbing displacement in the thickness direction.

( 2 ) In a predetermined fuel cell, the gas distribution part and the gas recovery part on both the anode side and the cathode side in the thickness direction are in contact with one of the frame and each separator, and a base part and a plurality of parts formed on the base part A displacement absorbing member for absorbing a displacement in the thickness direction having a spring function portion, and further between at least two film members in the thickness direction and corresponding to at least the gas distribution portion. A displacement absorbing member for absorbing displacement in the thickness direction is provided in a range corresponding to the range and the gas recovery unit.

  That is, the fuel cell of the present invention includes a membrane electrode assembly having a structure in which an electrolyte membrane is sandwiched between an anode and a cathode, and a frame disposed around the membrane electrode assembly and supporting the membrane electrode assembly. The anode side separator in the thickness direction that forms a gas flow path from the anode gas supply unit to the anode gas discharge unit between the frame and the anode, and the cathode gas supply unit from the cathode gas supply unit between the frame and the cathode And a separator on the cathode side in the thickness direction forming the gas flow path up to. In addition, the fuel cell has a gas flow along the gas flow direction between the frame and each separator, and between the anode gas supply unit and the anode and between the cathode gas supply unit and the cathode. A gas distribution section having an increased path width, in the gas flow direction between the frame and each separator, and between the anode and the anode gas discharge section and between the cathode and the cathode gas discharge section; A gas recovery section with a narrow gas flow path width is provided. Further, this fuel cell is formed in the base and the base at the gas distribution part and the gas recovery part on both the anode side and the cathode side in the thickness direction, and is in contact with one of the separators and the spring function part. A displacement absorbing member for absorbing a displacement in the thickness direction.

In another fuel cell of the present invention , a membrane electrode assembly having a structure in which an electrolyte membrane is sandwiched between an anode and a cathode, a membrane electrode assembly, and at least two film members are provided. The anode side in the thickness direction has a laminated structure and forms a gas flow path from the anode gas supply part to the anode gas discharge part between the frame supporting the membrane electrode assembly and the frame and the anode. The separator includes a separator on the cathode side in the thickness direction that forms a gas flow path from the cathode gas supply unit to the cathode gas discharge unit between the frame and the cathode. In addition, the fuel cell has a gas flow along the gas flow direction between the frame and each separator, and between the anode gas supply unit and the anode and between the cathode gas supply unit and the cathode. A gas distribution section having an increased path width, in the gas flow direction between the frame and each separator, and between the anode and the anode gas discharge section and between the cathode and the cathode gas discharge section; A gas recovery section with a narrow gas flow path width is provided. In addition, the fuel cell is in contact with the frame and one of the separators on the gas distribution part and the gas recovery part on both the anode side and the cathode side in the thickness direction, and has a base part and a plurality of spring functions formed on the base part. A displacement absorbing member for absorbing a displacement in the thickness direction having a portion, a range between at least two film members in the thickness direction and corresponding to at least a gas distribution portion, and a gas recovery portion A displacement absorbing member for absorbing displacement in the thickness direction is provided in a range corresponding to.

Further, the fuel cell stack of the present invention has a plurality of fuel cells are stacked, the stacked body at least one fuel cell is a fuel cell of the present invention, a pair of end for holding the laminate It comprises a plate and a pair of fastening members that fasten the pair of end plates.

According to the present invention, since any one of the above (1) and ( 2 ) is adopted, it is not necessary to use a frame or a separator provided with a convex portion of a predetermined size, which has caused a variation in accuracy. It is not necessary to interpose a plurality of elastic bodies of a predetermined size between the two. Therefore, it is possible to provide a fuel cell and a fuel cell stack that can achieve both reduction in electrical contact resistance between the membrane electrode assembly and the separator and suppression of frame breakage in the gas distribution unit and the gas recovery unit.

FIG. 1 is an exploded perspective view illustrating a fuel cell stack according to the first embodiment of the present invention. FIG. 2 is a perspective view showing an assembled fuel cell stack according to the first embodiment of the present invention. FIG. 3 is an exploded plan view for explaining the fuel cell constituting the fuel cell stack shown in FIG. FIG. 4 is an exploded plan view for explaining the separator that constitutes the fuel cell shown in FIG. FIG. 5 is a plan view showing the fuel cell constituting the fuel cell stack shown in FIG. 1 after assembling. 6A is a cross-sectional view showing the main part of the fuel cell along the line AA in FIG. 5, and FIG. 6B is the main part of the fuel cell along the line AA in FIG. It is typical sectional drawing which shows a part. FIG. 7 is a cross-sectional view (a) and (b) showing the main part of the fuel cell along a line at the same position as the AA line in FIG. 5 of the conventional fuel cell. FIG. 8 is a graph showing the relationship between anode / cathode length (W) / gas distribution section length (L) and inter-channel distribution variation in the fuel cell constituting the fuel cell stack according to the first embodiment of the present invention. is there. FIGS. 9A and 9B are schematic cross-sectional views showing the assembled fuel cell stack according to the first and second embodiments of the present invention. FIG. 10 (a) is an exploded view showing the main part of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the third embodiment of the present invention. FIG. 10B is a sectional view of the state of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the third embodiment of the present invention. It is sectional drawing which shows the assembly of the principal part. FIG. 11 is a cross-sectional view showing the fuel cell constituting the fuel cell stack according to the fourth embodiment of the present invention after assembling the main part of the fuel cell along the line AA in FIG. 5. FIG. FIG. 12 (a) shows the fuel cell constituting the fuel cell stack according to the fifth embodiment of the present invention after assembling the main part of the fuel cell along the line at the same position as the line AA in FIG. FIG. 12B and FIG. 12C are enlarged views of a portion surrounded by a one-dot chain line in FIG. FIG. 13A is an exploded view showing the main part of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the sixth embodiment of the present invention. FIG. 13B is a cross-sectional view of the state of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the sixth embodiment of the present invention. It is sectional drawing which shows the assembly of the principal part.

  Hereinafter, a fuel cell and a fuel cell stack according to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the dimension ratio of drawing quoted with the following forms is exaggerated on account of description, and may differ from an actual ratio.

(First form)
FIG. 1 is an exploded perspective view illustrating a fuel cell stack according to the first embodiment of the present invention. FIG. 2 is a perspective view showing the assembled fuel cell stack according to the first embodiment of the present invention. Further, FIG. 3 is an exploded plan view for explaining the fuel cell constituting the fuel cell stack shown in FIG. FIG. 4 is a plan view of a disassembled state for explaining the separator constituting the fuel cell shown in FIG. Further, FIG. 5 is a plan view showing the assembled fuel cell that constitutes the fuel cell stack shown in FIG. 6A is a cross-sectional view showing the main part of the fuel cell along the line AA in FIG. 5, and FIG. 6B is a fuel along the line AA in FIG. It is typical sectional drawing which shows the principal part of a battery.

  As shown in FIG. 1, the fuel cell stack 1 according to the first embodiment has one end portion in the stacking direction (in FIG. 1) with respect to a stack 50 having a structure in which fuel cells 10 each having a rectangular plate shape are stacked. An end plate 53A is provided on the right end) via a current collecting plate 51A and a spacer 52, and an end plate 53B is provided on the other end via a current collecting plate 51B. The fuel cell stack 1 is provided with fastening plates 54A and 54B, which are examples of fastening members, on both surfaces (upper and lower surfaces in FIG. 1) on the long side of the fuel cell 10 with respect to the stacked body 50. Reinforcing plates 55A and 55B are provided on both surfaces on the short side.

  The fuel cell stack 1 connects the fastening plates 54A and 54B and the reinforcing plates 55A and 55B to both end plates 53A and 53B by bolts B. In this way, the fuel cell stack 1 has a case-integrated structure as shown in FIG. 2. The stack 50 is restrained and pressurized in the stacking direction to apply a predetermined contact surface pressure to each fuel cell 10. Maintains good gas sealability and conductivity.

  The fuel cell 10 is also referred to as a single cell in the fuel cell stack 1, and as shown in FIGS. 1 and 3 to 6, a membrane electrode assembly 11 and an anode gas / cathode gas / cooling fluid supply unit. A frame 12 having S1 to S3 and discharge parts D1 to D3 and arranged around the membrane electrode assembly 11 to support the membrane electrode assembly 11, and an anode gas, cathode gas and cooling fluid supply unit A pair of separators 13 and 13 that have S1 to S3 and discharge portions D1 to D3 and sandwich the membrane electrode assembly 11 and the frame 12 are provided. In addition, each supply part S1-S3 and each discharge part D1-D3 are mutually connected in the thickness direction, and form each flow path. Although not shown, a part or all of the supply unit and the discharge unit may have a reverse positional relationship.

  Furthermore, the membrane electrode assembly 11 is generally called MEA (Membrane Electrode Assembly) and has a structure in which an electrolyte membrane 11a made of a solid polymer is sandwiched between an anode 11b and a cathode 11c (see FIG. 6). In the membrane electrode assembly 11, an anode gas (hydrogen-containing gas) is supplied to the anode 11b and a cathode gas (oxygen-containing gas / air) is supplied to the cathode 11c to generate electric power through an electrochemical reaction. The membrane electrode assembly 11 includes those having gas diffusion layers 11d and 11e made of carbon paper or a porous body on the surfaces of the anode 11b and the cathode 11c.

  The frame 12 is integrated with the membrane electrode assembly 11 by, for example, injection molding, thermocompression bonding with another film such as a PEN frame, or adhesion with an adhesive. In this embodiment, the film member 12a and the membrane electrode junction are integrated. The body electrolyte membrane 11a is laminated to form a rectangular shape with the membrane electrode assembly 11 in the center (see FIG. 3). Further, the frame 12 has three supply parts S1 to S3 and three discharge parts D1 to D3 arranged at both ends, and the membrane electrode assembly 11 is connected from the anode gas supply part S1 or the cathode gas supply part S3. A region reaching the anode 11b or the cathode 11c is a gas distribution part D, and a region from the anode 11b or the cathode 11c of the membrane electrode assembly 11 to the anode gas discharge part D3 or the cathode gas discharge part D1 is a gas recovery part C. Each of the frame 12 and the separators 13 and 13 has a rectangular shape having substantially the same vertical and horizontal dimensions.

  Furthermore, each separator 13 is a metal plate member 13a having an inverted shape, and is made of, for example, stainless steel, and is fitted with a hole 13f of another metal plate member 13c using press working or a convex shape 13b. It can be formed into a suitable shape by combination. The separator 13 in the illustrated example has at least a central portion corresponding to the membrane electrode assembly 11 formed in a concavo-convex shape. This separator 13 has ribs (cross-sectional uneven shape) 13d continuously in the long side direction, and forms a gas flow path for anode gas and cathode gas between the membrane electrode assembly 11 by corrugated recesses. To do.

  Each separator 13 is provided with another plate member 13c in which a plurality of rectangular convex portions 13e are arranged vertically and horizontally in the gas distribution part D and the gas recovery part C. These convex portions 13e are intended to maintain the reaction gas flow space by contacting the frame 12 when the displacement of the fuel cell 10 in the thickness direction is caused by the change of the membrane electrode assembly 11 over time. .

  Although not shown, the fuel cell may have a structure in which the unevenness of the separator on the cathode side and the anode side is shifted by a half pitch or a structure in which the unevenness is matched.

  Further, as shown in FIGS. 3 to 5, the fuel cell 10 is provided with a seal S between the edges of the frame 12 and each separator 13 and around the supply parts S1 to S3 and the discharge parts D1 to D3. It is. In a state where a plurality of fuel cells 10 are stacked, a seal S is also provided between the fuel cells 10, that is, between adjacent separators 13.

  In addition, the seal S hermetically separates the flow areas of the cathode gas, the anode gas, and the cooling liquid between the individual layers, and supplies only the predetermined fluid between the supply parts S1 to S3 and Openings are provided at appropriate locations on the peripheral edge of the discharge portions D1 to D3.

  The fuel cell 10 having the above-described configuration constitutes the fuel cell stack 1 by stacking a plurality of fuel cells 10 as described above. As shown in FIG. 6, the fuel cell stack 1 forms a coolant circulation space F between adjacent fuel cells 10.

  Further, the fuel cell stack 1 has a plurality of projections that form a spring function portion, which is in contact with the gas distribution portion D and the gas recovery portion C, in contact with one of the frame 12 and the separator 13 and in detail at a base portion described later. A displacement absorbing member 14 that absorbs the displacement in the thickness direction.

  With such a configuration, the displacement absorbing member is crushed during lamination. In other words, after stacking, the gas distribution part and the gas recovery part of the frame are held from the separators on both sides via the displacement absorbing member, and the displacement absorbing member is further bent to reliably push the separator against the anode and cathode of the membrane electrode assembly. You can guess. Therefore, even if there is a variation in accuracy in the height of the ribs (concave / convex structure) of the separator facing the anode and cathode of the gas distribution part and gas recovery part of the frame and the membrane electrode assembly, the membrane electrode is joined with an appropriate surface pressure. Since the rib can be brought into contact with the anode or the cathode of the body, it is possible to prevent or suppress performance degradation due to an increase in electrical contact resistance and to support the frame in the gas distribution part and the gas recovery part. Therefore, even if a gas differential pressure occurs between the anode side and the cathode side, damage due to flapping of the frame can be prevented.

  On the other hand, FIG. 7 is a cross-sectional view (a) and (b) showing the main part of the fuel cell along the line at the same position as the AA line in FIG. 5 of the conventional fuel cell. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fuel cell stack 1 according to the conventional configuration does not include a displacement absorbing member for absorbing displacement in the thickness direction in the gas distribution portion D (and a gas recovery portion (not shown)). Because of this configuration, when the accuracy of the rib (uneven structure) height of the separator facing the anode or cathode of the membrane electrode assembly varies and the rib height is low, Since the rib cannot be brought into contact with the anode or the cathode of the membrane electrode assembly by the surface pressure, the performance may be deteriorated due to an increase in electrical contact resistance (see FIG. 7A). On the other hand, because of such a configuration, when the accuracy variation occurs in the rib (uneven structure) height of the separator facing the anode or cathode of the membrane electrode assembly, and the rib height is high, Since the frame cannot be supported by the gas distribution unit and the gas recovery unit, when the gas differential pressure is generated between the anode side and the cathode side, the frame is damaged by flapping as shown by the downward arrow and the broken line. (See FIG. 7B).

  FIG. 8 is a graph showing the relationship between anode / cathode length (W) / gas distribution section length (L) and inter-channel distribution variation in the fuel cell constituting the fuel cell stack according to the first embodiment of the present invention. is there.

  In the fuel cell stack according to the first embodiment, as shown in FIG. 3, the length (W) of the anode or cathode with respect to the length (L) of the gas distribution section in the fuel cell (the length of anode or cathode (W ) / Gas distribution part length (L)) is preferably 5 or less. The distribution distribution performance between channels in the gas distribution section depends on the length of the anode or cathode (W) / the length of the gas distribution section (L). The smaller this value, the smaller the distribution distribution of gas in the gas flow path, and the performance improves.

(First and second forms)
FIGS. 9A and 9B are schematic cross-sectional views showing the assembled fuel cell stack according to the first and second embodiments of the present invention. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 9A, in the fuel cell stack 1 according to the first embodiment of the present invention, end plates 53A and 53B and fastening plates 54A and 54B, which are examples of fastening members, are directly fastened. This is because the fuel cell stack 1 according to the first embodiment of the present invention has the displacement absorbing member 14 in the stacked body 50 (see FIG. 6). That is, the fuel cell stack 1 according to the first embodiment of the present invention has a spring 61 and a spring support outside the stacked body 50 in the fuel cell stack 1 according to the second embodiment of the present invention as shown in FIG. There is an advantage that it is not necessary to have the external spring mechanism 60 composed of the plate 62.

(Third form)
FIG. 10 (a) is an exploded view showing the main part of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the third embodiment of the present invention. FIG. 10B is a sectional view of the state of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the third embodiment of the present invention. It is sectional drawing which shows the assembly of the principal part. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 10, the fuel cell stack according to the third embodiment has a spring function as a displacement absorbing member 14, which is in contact with the frame 12 and the separator 13, and is formed on the base 14 a and a metal substrate as the base 14 a. A displacement absorbing member for absorbing displacement in the thickness direction is provided, having a plurality of cantilevered metal spring pieces as convex portions constituting the portion 14b. Such a displacement absorbing member can be formed to have spring elasticity by plastic working a metal member.

  With such a configuration, the spring function portion of the displacement absorbing member is crushed during lamination. That is, after stacking, the gas distribution part and the gas recovery part of the frame are held from the separators on both sides via the displacement absorbing member, and the spring function part of the displacement absorbing member is further bent to ensure the anode and cathode of the membrane electrode assembly. Can be pressed against the separator. Therefore, even if there is a variation in accuracy in the height of the ribs (concave / convex structure) of the separator facing the anode and cathode of the gas distribution part and gas recovery part of the frame and the membrane electrode assembly, the membrane electrode is joined with an appropriate surface pressure. Since the rib can be brought into contact with the anode or the cathode of the body, it is possible to prevent or suppress performance degradation due to an increase in electrical contact resistance and to support the frame in the gas distribution part and the gas recovery part. Therefore, even if a gas differential pressure occurs between the anode side and the cathode side, damage due to flapping of the frame can be prevented.

(4th form)
FIG. 11 is a cross-sectional view showing the fuel cell constituting the fuel cell stack according to the fourth embodiment of the present invention after assembling the main part of the fuel cell along the line AA in FIG. 5. FIG. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 11, the fuel cell stack according to the fourth embodiment is, as the displacement absorbing member 14, in contact with the frame 12 and the separator 13, and formed on the base portion 14 a and the base portion 14 a to constitute the spring function portion 14 b. A displacement absorbing member for absorbing a displacement in the thickness direction. In this embodiment, the base portion 14a and the spring function portion 14b are made of a resin material. Such a displacement absorbing member can be formed by injection molding a resin material. Moreover, it can form by sticking a suitable resin film.

  With such a configuration, the spring function portion of the displacement absorbing member is crushed during lamination. That is, after stacking, the gas distribution part and the gas recovery part of the frame are held from the separators on both sides via the displacement absorbing member, and the spring function part of the displacement absorbing member is further bent to ensure the anode and cathode of the membrane electrode assembly. Can be pressed against the separator. Therefore, even if there is a variation in accuracy in the height of the ribs (concave / convex structure) of the separator facing the anode and cathode of the gas distribution part and gas recovery part of the frame and the membrane electrode assembly, the membrane electrode is joined with an appropriate surface pressure. Since the rib can be brought into contact with the anode or the cathode of the body, it is possible to prevent or suppress performance degradation due to an increase in electrical contact resistance and to support the frame in the gas distribution part and the gas recovery part. Therefore, even if a gas differential pressure occurs between the anode side and the cathode side, damage due to flapping of the frame can be prevented.

(5th form)
FIG. 12 (a) shows the fuel cell constituting the fuel cell stack according to the fifth embodiment of the present invention after assembling the main part of the fuel cell along the line at the same position as the line AA in FIG. FIG. 12B and FIG. 12C are enlarged views of a portion surrounded by a one-dot chain line in FIG. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 12, the fuel cell stack according to the fifth embodiment has a plurality of protrusions in contact with the frame in a range in which the separator 13 corresponds to a gas distribution unit (and a gas recovery unit (not shown)). It has a part 13e. The fuel cell stack has a thickness indicated by 12b in a range between two film members 12a in the thickness direction and a range corresponding to the gas distribution unit (and a gas recovery unit (not shown)). A displacement absorbing member for absorbing the vertical displacement is provided. The displacement absorbing member 12b is preferably, for example, an adhesive that bonds the film members 12a together and an elastic member that has spring elasticity even after curing.

  Even with this configuration, the elastic member, which is a displacement absorbing member, is crushed during lamination. That is, even if the convex part of the gas distribution part (or a gas recovery part (not shown)) of the separator is low, the displacement absorbing member in the range corresponding to the gas distribution part (and the gas recovery part (not shown)) of the frame after stacking. Even if all or part of the bending is eliminated and held from the separators on both sides (see FIG. 12B), and the convex part of the gas distribution part (or a gas recovery part (not shown)) of the separator is high. After the lamination, the displacement absorbing member in a range corresponding to the gas distribution part (and a gas recovery part (not shown)) of the frame is bent, so that the separator can be surely pressed against the anode and the cathode (see FIG. 12C). ). Therefore, even if there is a variation in accuracy in the height of the ribs (concave / convex structure) of the separator facing the anode and cathode of the gas distribution part and gas recovery part of the frame and the membrane electrode assembly, the membrane electrode is joined with an appropriate surface pressure. Since the rib can be brought into contact with the anode or the cathode of the body, it is possible to prevent or suppress performance degradation due to an increase in electrical contact resistance and to support the frame in the gas distribution part and the gas recovery part. Therefore, even if a gas differential pressure occurs between the anode side and the cathode side, damage due to flapping of the frame can be prevented.

(Sixth form)
FIG. 13A is an exploded view showing the main part of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the sixth embodiment of the present invention. FIG. 13B is a cross-sectional view of the state of the fuel cell along the line AA in FIG. 5 of the fuel cell constituting the fuel cell stack according to the sixth embodiment of the present invention. It is sectional drawing which shows the assembly of the principal part. Note that the same components as those of the previous embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  As shown in FIG. 13, the fuel cell stack according to the sixth embodiment has a spring function as a displacement absorbing member 14 that is in contact with the frame 12 and the separator 13 and is formed on the base 14a and the base 14a. A displacement absorbing member for absorbing displacement in the thickness direction is provided, having a plurality of cantilevered metal spring pieces as convex portions constituting the portion 14b. Further, this fuel cell stack has a thickness indicated by 12b between the two film members 12a in the thickness direction and in a range corresponding to the gas distribution unit (and a gas recovery unit (not shown)). A displacement absorbing member for absorbing the vertical displacement is provided.

  Even with this configuration, the spring function portion of the displacement absorbing member is crushed during lamination. That is, after stacking, the gas distribution part and the gas recovery part of the frame are held from the separators on both sides via the displacement absorbing member, and further between the spring function part of the displacement absorbing member and the two film members, and the gas distribution When the displacement absorbing member disposed in the range corresponding to the range (and the gas recovery unit not shown) is bent, the separator can be reliably pressed against the anode and cathode of the membrane electrode assembly. Therefore, even if there is a variation in accuracy in the height of the ribs (concave / convex structure) of the separator facing the anode and cathode of the gas distribution part and gas recovery part of the frame and the membrane electrode assembly, the membrane electrode is joined with an appropriate surface pressure. Since the rib can be brought into contact with the anode or the cathode of the body, it is possible to prevent or suppress performance degradation due to an increase in electrical contact resistance and to support the frame in the gas distribution part and the gas recovery part. Therefore, even if a gas differential pressure occurs between the anode side and the cathode side, damage due to flapping of the frame can be prevented.

  As mentioned above, although this invention was demonstrated with some forms, this invention is not limited to these, A various deformation | transformation is possible within the range of the summary of this invention.

  For example, the configurations described in the fuel cells and fuel cell stacks of each embodiment described above are not limited to each embodiment, and for example, the configurations of each embodiment may be combined other than each embodiment described above, or the configuration details Can be changed.

S1 Anode gas supply unit S3 Cathode gas supply unit D1 Cathode gas supply unit D3 Anode gas discharge unit D Gas distribution unit C Gas recovery unit 1 Fuel cell stack 10 Fuel cell 11 Membrane electrode assembly 11a Electrolyte membrane 11b Anode 11c Cathode 11d, 11e Gas diffusion layer 12 Frame 12a Film member 12b Displacement absorbing member 13 Separator 13e Convex part 14 Displacement absorbing member 14a Base part 14b Spring functional part 50 Laminate 53A, 53B End plates 54A, 54B Fastening member

Claims (9)

A membrane electrode assembly having a structure in which an electrolyte membrane is sandwiched between an anode and a cathode;
Disposed around the upper Kimaku electrode assembly, and a frame supporting the membrane electrode assembly,
An anode-side separator in the thickness direction that forms a gas flow path from the anode gas supply unit to the anode gas discharge unit between the frame and the anode;
A cathode-side separator in the thickness direction that forms a gas flow path from the cathode gas supply unit to the cathode gas discharge unit between the frame and the cathode,
Gas flow paths between the frame and the separators and between the anode gas supply unit and the anode and between the cathode gas supply unit and the cathode along the gas flow direction. It has a gas distribution part that expands in width,
Gas flow paths between the frame and the separators and along the gas flow direction between the anode and the anode gas discharge unit and between the cathode and the cathode gas discharge unit, respectively. It has a gas recovery section that narrows the width,
The gas distribution part and the gas recovery part on both the anode side and the cathode side in the thickness direction are in contact with one of the frame and each of the separators, and are formed on the base part and the base part. A fuel cell comprising a displacement absorbing member for absorbing a displacement in the thickness direction, having a plurality of convex portions constituting the same.   In a plane perpendicular to the thickness direction, the anode in a direction perpendicular to the perpendicular to the length (L) of the perpendicular from the anode gas supply part or the cathode gas supply part to the anode or cathode of the membrane electrode assembly 2. The fuel cell according to claim 1, wherein the cathode length (W) ratio (W / L) is 5 or less. The base is made of a metal substrate, and the convex is made of a cantilevered metal spring piece, or the base and the convex are made of a resin material. Fuel cell. The frame has a structure in which at least two film members are laminated ,
Upper Symbol each separator, the range corresponding to the range and the gas recovery unit corresponding to the gas distribution portion has a plurality of convex portions in contact with said frame,
Displacement absorption for absorbing displacement in the thickness direction between the at least two film members in the thickness direction and at least in a range corresponding to the gas distribution part and a range corresponding to the gas recovery part The fuel cell according to claim 1, further comprising a member. A membrane electrode assembly having a structure in which an electrolyte membrane is sandwiched between an anode and a cathode;
A frame that is disposed around the membrane electrode assembly and has a structure in which at least two film members are laminated, and a frame that supports the membrane electrode assembly;
An anode-side separator in the thickness direction that forms a gas flow path from the anode gas supply unit to the anode gas discharge unit between the frame and the anode;
A cathode-side separator in the thickness direction that forms a gas flow path from the cathode gas supply unit to the cathode gas discharge unit between the frame and the cathode,
Gas flow paths between the frame and the separators and between the anode gas supply unit and the anode and between the cathode gas supply unit and the cathode along the gas flow direction. It has a gas distribution part that expands in width,
Gas flow paths between the frame and the separators and along the gas flow direction between the anode and the anode gas discharge unit and between the cathode and the cathode gas discharge unit, respectively. It has a gas recovery section that narrows the width,
To the gas distribution portion of both the anode side and the cathode side and the gas recovery section in the thickness direction, with contact with one and the frame and the respective separators, base and a plurality of spring function formed in the base portion A displacement absorbing member for absorbing the displacement in the thickness direction having a portion,
Displacement absorption for absorbing displacement in the thickness direction between the at least two film members in the thickness direction and at least in a range corresponding to the gas distribution part and a range corresponding to the gas recovery part A fuel cell comprising a member.   In a plane perpendicular to the thickness direction, the anode in a direction perpendicular to the perpendicular to the length (L) of the perpendicular from the anode gas supply part or the cathode gas supply part to the anode or cathode of the membrane electrode assembly 6. The fuel cell according to claim 4 or 5, wherein the ratio (W / L) of the cathode length (W) is 5 or less. The said base part consists of metal substrates, and the said spring function part consists of a cantilever-type metal spring piece, or the said base part and the said spring function part consist of resin materials, It is characterized by the above-mentioned. Fuel cell. A stack having a structure in which a plurality of fuel cells are stacked, and at least one of the fuel cells is the fuel cell according to any one of claims 1 to 7,
A pair of end plates sandwiching the laminate,
A fuel cell stack comprising: a pair of fastening members that fasten the pair of end plates.   9. The fuel cell stack according to claim 8, wherein the end plate and the fastening member are directly fastened.

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